1. The telemetering device for measuring the thickness of an oil film between a piston and a cylinder sleeve based on a capacitance method is characterized in that: the device comprises a power supply voltage stabilizing module (1), a capacitance acquisition module (2), a wireless communication module (3), an upper computer data processing module (4) and a transformation piston (5);

the power supply voltage stabilizing module (1) mainly comprises a battery (1.1), a power supply voltage stabilizing chip, a peripheral circuit (1.2) of the power supply voltage stabilizing chip and a temperature control switch (1.3);

the capacitance acquisition module (2) comprises a capacitance acquisition chip and a peripheral circuit (2.1) thereof, a capacitor (2.2) to be detected, a cylinder sleeve and capacitance acquisition chip connecting device (2.3) and a probe fixing and connecting part (2.4); the capacitor (2.2) to be tested mainly comprises a capacitor electrode probe (2.2.1) to be tested, a cylinder sleeve (2.2.2) and lubricating oil (2.2.3); the two capacitance electrodes of the capacitor to be measured are respectively a probe (2.2.1) of the capacitor to be measured and a cylinder sleeve (2.2.2), namely, one electrode is the probe (2.2.1) of the capacitor to be measured fixed on the improved piston (5), and the other electrode is the cylinder sleeve (2.2.2); the cylinder sleeve and capacitor acquisition chip connecting device (2.3) mainly comprises a sliding conductor (2.3.1), a sliding conductor support frame (2.3.2), an elastic element (2.3.3), a sliding conductor and elastic element connecting piece (2.3.4) and a cylinder sleeve acquisition end lead (2.3.5); the probe fixing and connecting part (2.4) mainly comprises high-temperature insulating glue (2.4.1), a shielding case (2.4.2) and a probe acquisition end lead (2.4.3); a capacitance electrode probe (2.2.1) to be tested is directly connected to a capacitance acquisition chip and a peripheral circuit (2.1) thereof through a probe acquisition end lead (2.4.3); the cylinder sleeve (2.2.2) is connected with the capacitance acquisition chip and a peripheral circuit (2.1) thereof through a sliding conductor (2.3.1) and a cylinder sleeve acquisition end lead (2.3.5); the sliding conductor support frame (2.3.2), the elastic element (2.3.3), the sliding conductor and elastic element connecting piece (2.3.4) are used for keeping the sliding conductor and the cylinder sleeve in a compressed state and establishing electrical connection;

the wireless communication module (3) comprises an in-cylinder wireless communication module (3.1) and an out-cylinder wireless communication module (3.2), wherein the in-cylinder wireless communication module (3.1) and the out-cylinder wireless communication module (3.2) are respectively composed of a wireless communication chip, a peripheral circuit (3.1.1) of the wireless communication chip and an antenna (3.1.2);

the upper computer data processing module (4) is used for realizing data visual display and data storage on the telemetering measurement data, and the telemetering measurement data is a capacitance value reflecting the thickness change of an oil film between the piston and the cylinder sleeve;

the improved piston (5) is a piston which is provided with a capacitor electrode probe (2.2.1) to be tested, a cylinder sleeve and a capacitor acquisition chip connecting device (2.3) for adaptive improved processing, and an engine body does not need to be modified; the cylinder sleeve in the capacitance acquisition module (2) is connected with the capacitance acquisition chip connecting device (2.3) in a mechanical mode through adaptation improvement of a modified piston (5), a capacitance electrode probe (2.2.1) to be detected in the capacitance acquisition module (2) is fixed on the modified piston (5) through high-temperature glue, and the rest part of the capacitance acquisition module (2) is fixed on the modified piston through the high-temperature glue or the mechanical connection mode; the power supply voltage stabilizing module (1) and the in-cylinder wireless communication module (3.1) are fixed on the improved piston (5) in a high-temperature glue or mechanical connection mode; a power supply voltage stabilizing chip of the power supply voltage stabilizing module (1) and a peripheral circuit (1.2) thereof, a capacitance acquisition chip of the capacitance acquisition module (2) and a peripheral circuit (2.1) thereof, a wireless communication chip of the in-cylinder wireless communication module (3.1) and a peripheral circuit (3.1.1) thereof are manufactured into one or more integrated circuit boards, the plurality of integrated circuit boards are electrically connected by using a lead, and the circuit board, the battery (1.1) and the temperature control switch (1.3) are fixed on the inner wall of the skirt part of the modified piston (5); the following requirements are required when the circuit board and the battery (1.1) are installed: the mounting positions of the circuit board and the battery (1.1) need to be close to the inner wall of the skirt part of the modified piston (5) as much as possible, so that the circuit board and the battery (1.1) are ensured not to interfere with a connecting rod when an engine runs; and secondly, considering that the temperature of the piston is reduced from the top to the bottom and the maximum working temperature limit of the electronic components exists, the circuit board and the battery (1.1) are placed at the position, close to the bottom, of the inner wall of the skirt part of the modified piston (5) as much as possible.

2. The telemetering device for measuring the thickness of an oil film between a piston and a cylinder liner based on a capacitance method as claimed in claim 1, wherein: the adaptation improvement mode is that the original piston is respectively provided with a groove and a hole to form a modified piston (5); punching a hole at a position of an original piston skirt part to-be-measured point, installing a capacitance electrode probe (2.2.1) to be measured in the hole, enabling the working surface of the capacitance electrode probe (2.2.1) to be measured to be flush with the outer wall of the skirt part of the modified piston (5), enabling the side surface of the skirt part to keep a preset gap with the hole, enabling the capacitance electrode probe (2.2.1) to be measured to be made of a metal conductor, placing a shielding case (2.4.2) in the gap, filling high-temperature-resistant insulating glue (2.4.3) in the gap, keeping the capacitance electrode probe (2.2.1) to be measured, the shielding case (2.4.2) and the modified piston (5) to be insulated from each other, and enabling the capacitance electrode probe (2.2.1) to be measured and the shielding case (2.4.2) to be fixed in the hole; the cylinder sleeve and the capacitance acquisition chip connecting device (2.3) are connected to the improved piston (5) in a mechanical connection mode.

3. The telemetering device for measuring the thickness of an oil film between a piston and a cylinder liner based on a capacitance method as claimed in claim 1, wherein: the sliding conductor support frame (2.3.2) of the cylinder sleeve and capacitance acquisition chip connecting device (2.3) and the sliding conductor and elastic element connecting piece (2.3.4) are made of high-strength engineering plastics and are insulated from the improved piston (5) and the sliding conductor (2.3.1).

4. The telemetering device for measuring the thickness of an oil film between a piston and a cylinder liner based on a capacitance method as claimed in claim 1, wherein: the antenna (3.1.2) is not integrated in the circuit board, is led out from the circuit board and is fixed at a proper position on the improved piston (5) by using high-temperature glue or a mechanical connection mode.

5. The telemetering method for measuring the thickness of the oil film between the piston and the cylinder sleeve based on the capacitance method is realized based on the telemetering device for measuring the thickness of the oil film between the piston and the cylinder sleeve based on the capacitance method as claimed in claim 1, 2, 3 or 4, and is characterized in that: the improved piston (5) does high-speed reciprocating motion in the cylinder sleeve, the lubrication state between the improved piston (5) and the cylinder sleeve (2.2.2) is hydrodynamic lubrication at most positions in the stroke of the improved piston (5), the lubricating oil (2.2.3) is filled in a friction pair gap, and the lubricating oil (2.2.3) is a non-conductive material, so that a capacitance electrode probe (2.2.1) of a capacitor to be tested, the cylinder sleeve (2.2.2) and the lubricating oil (2.2.3) form a capacitor, and a capacitance value reflecting the change of the thickness of an oil film between the piston and the cylinder sleeve is measured through a capacitance acquisition chip and a peripheral circuit (2.1) of the capacitance acquisition chip; the capacitance acquisition module 2 transmits acquired capacitance signals to the in-cylinder wireless communication module (3.1), the in-cylinder wireless communication module (3.1) transmits the capacitance signals to the out-cylinder wireless communication module (3.2), the out-cylinder wireless communication module (3.2) transmits the capacitance signals to the upper computer data processing module (4) for data processing, the oil film thickness of the measuring point is deduced through a parallel plate capacitor formula, and the upper computer data processing module (4) realizes data visual display and data storage on the oil film thickness data of the measuring point; the in-cylinder wireless communication module (3.1) and the out-cylinder wireless communication module (3.2) realize two-way communication; the upper computer data processing module (4) sends an instruction, and the instruction is transmitted to the capacitance acquisition chip and the peripheral circuit (2.1) thereof through the wireless communication module (3), so that the capacitance acquisition module (2) is controlled.

6. The telemetry method for measuring the thickness of an oil film between a piston and a cylinder liner based on a capacitance method as claimed in claim 5, wherein: when single-point measurement is carried out, the abrasion loss at the measuring point of the piston (5) is monitored in real time along with the change of time according to the change of the oil film thickness at the tracked measuring point; when multi-point measurement is carried out, the capacitance electrode probes (2.2.1) to be measured are arranged on the thrust side and the secondary thrust side of the piston, and the second-order motion condition of the piston is monitored in real time according to the thickness change of the oil film at the tracked measuring point.

Background

With the modern development of society, the environmental protection consciousness of energy conservation and emission reduction is in depth. The internal combustion engine has wide application field and is widely used in the industries of vehicles, ships, aerospace, power stations and the like. The internal combustion engine is used as a part which runs under an extreme working condition, the piston moves at a high speed in the cylinder sleeve by means of power provided by fuel combustion, so that the serious friction and wear problems are certainly existed, the serious wear problems can cause the reduction of the thermal efficiency, the increase of the fuel consumption and the increase of the emission of polluted gas, the reduction of the friction and wear in the internal combustion engine is always a hot point for the research of the internal combustion engine, the friction performance of the internal combustion engine is optimized, and the influence factors and the influence law are required to be searched.

Due to the complex friction process, the factors influencing the frictional wear are numerous. The important influence factors of the friction and the abrasion of the internal combustion engine are the material property of a friction pair, the lubrication condition, the lubricating oil parameter, the contact surface force and the like, the lubrication condition and the contact surface force of the friction pair are influenced by the motion state of the piston, and the piston not only has reciprocating motion along the axis of a cylinder sleeve, but also has transverse motion vertical to the axis of the cylinder sleeve and rotary motion around a piston pin, namely second-order motion of the piston in the internal combustion engine. The existence of piston second order motion, make the piston strike the cylinder liner when being high-speed reciprocating motion, contact surface pressure between piston and the cylinder liner improves in the twinkling of an eye in striking, destroy lubricating oil film, the frictional state is changed into mixed friction or dry friction by liquid friction, the piston, the frictional wear aggravation between piston ring group and the cylinder liner, and the wearing and tearing of piston ring group will lead to the air leakage to increase, make the combustion chamber maximum pressure reduce on the one hand, the fuel consumption rate increases, the thermal efficiency reduces, on the other hand the fuel gets into the oil pan makes machine oil go bad, reduce the lubricated effect of machine oil, aggravation frictional wear, form vicious circle.

Therefore, the motion state of the piston needs to be researched, and at present, the research modes comprise theoretical analysis, numerical simulation and experimental monitoring, wherein the experimental monitoring on the abrasion of the piston and the motion state of the piston can be realized by measuring the thickness of an oil film between the piston and a cylinder sleeve. At present, three methods for measuring the thickness of a piston oil film are mainly used: the method comprises an ultrasonic method, a laser induced fluorescence method and a capacitance method, wherein the ultrasonic method and the capacitance method can be used for measuring the internal combustion engine in a working state, and the capacitance method is used for measuring due to high precision and easy realization. When the traditional capacitance method is used for measuring the thickness of the oil film, a plurality of capacitance probes to be measured are placed in an internal combustion engine body, and the thickness change of the oil film at a measuring point on a cylinder sleeve when a piston is at different crank angles can be measured. The method is convenient for measuring the minimum oil film thickness of the piston ring, but cannot continuously measure the oil film thickness change of a fixed measuring point of the piston. The test system is classified into a storage test type, a wired transmission type and a remote measurement type according to a signal transmission mode. The method has the advantages that the improvement on the internal combustion engine is small, the whole structure of the test system is simple, but the test machine needs to be disassembled after each test, and the operation is complex. Wired transmission allows real-time monitoring of data, but makes major modifications to the engine and the placement of the measurement system in the piston inconvenient. The remote measurement type can monitor the change of the lubricating oil film in real time, and has little change to the internal combustion engine, but the data transmission speed is slightly lower than that of a wired transmission method.

Disclosure of Invention

The invention discloses a telemetering device and a method for measuring the thickness of an oil film between a piston and a cylinder sleeve based on a capacitance method, aiming at solving the problems that the traditional method for measuring the thickness of the oil film between the piston and the cylinder sleeve when an engine runs based on the capacitance method can not directly monitor the change of the thickness of the oil film between a preset measuring point of the piston and the cylinder sleeve, the engine is greatly changed and the like: the telemetering measurement of the oil film thickness between the piston and the cylinder sleeve is realized based on a capacitance method, the data visualization display and the data storage of the telemetering measurement data can be realized, and in addition, the following advantages are brought by placing a capacitance acquisition module in the piston: (1) the capacitance electrode probe to be measured is placed on the piston, so that the thickness change of an oil film during the movement of the piston can be directly tracked and measured; (2) the remote measurement of the thickness of an oil film between the piston and the cylinder sleeve can be realized only by carrying out adaptive improved processing of installing a capacitance electrode probe to be measured on the piston without modifying an engine body, so that the processing complexity and cost are obviously reduced; (3) by using the sliding conductor and the lead to connect the cylinder sleeve and the capacitance acquisition chip instead of directly using the lead to connect, the mounting structure of the connecting device can be greatly simplified, and the possibility of damage to the measuring device caused by the fact that the lead is wound on moving parts in the cylinder is reduced.

The object of the present invention is achieved by the following technical means.

The invention discloses a telemetering device for measuring the thickness of an oil film between a piston and a cylinder sleeve based on a capacitance method.

The power supply voltage stabilizing module mainly comprises a battery, a power supply voltage stabilizing chip, a peripheral circuit of the power supply voltage stabilizing chip and a temperature control switch.

The capacitance acquisition module comprises a capacitance acquisition chip and a peripheral circuit thereof, a capacitor to be detected, a cylinder sleeve and capacitance acquisition chip connecting device, and a probe fixing and connecting part. The capacitor to be tested mainly comprises a capacitor electrode probe to be tested, a cylinder sleeve and lubricating oil. The two capacitance electrodes of the capacitor to be tested are respectively the electrode probe of the capacitor to be tested and the cylinder sleeve, namely, one electrode is the electrode probe of the capacitor to be tested fixed on the improved piston, and the other electrode is the cylinder sleeve. The connecting device of the cylinder sleeve and the capacitance acquisition chip mainly comprises a sliding conductor, a sliding conductor support frame, an elastic element, a sliding conductor and elastic element connecting piece and a cylinder sleeve acquisition end lead. The probe fixing and connecting part mainly comprises high-temperature insulating glue, a shielding case and a probe acquisition end lead. The capacitance electrode probe to be tested is directly connected to the capacitance acquisition chip and the peripheral circuit thereof through the probe acquisition end lead. The cylinder sleeve is connected with the capacitance acquisition chip and the peripheral circuit thereof through a sliding conductor and a cylinder sleeve acquisition end lead. The sliding conductor support frame, the elastic element, the sliding conductor and elastic element connecting piece are used for keeping the sliding conductor and the cylinder sleeve in a compression state and establishing electrical connection.

The wireless communication module comprises an in-cylinder wireless communication module and an out-cylinder wireless communication module, and the in-cylinder wireless communication module and the out-cylinder wireless communication module are respectively composed of a wireless communication chip, a peripheral circuit of the wireless communication chip and an antenna.

The upper computer data processing module is used for realizing data visual display and data storage on the telemetering measurement data, and the telemetering measurement data is a capacitance value reflecting the change of the thickness of an oil film between the piston and the cylinder sleeve.

The improved piston is a piston which is adaptive and improved to process and is provided with a capacitance electrode probe to be detected, a cylinder sleeve and a capacitance acquisition chip connecting device, and an engine body does not need to be modified. The cylinder sleeve in the capacitance acquisition module is mechanically connected with the capacitance acquisition chip connecting device through adaptation improvement of a transformed piston, a capacitance electrode probe to be detected in the capacitance acquisition module is fixed on the transformed piston through high-temperature glue, and the rest of the capacitance acquisition module is fixed on the transformed piston through the high-temperature glue or a mechanical connection mode. The power supply voltage stabilizing module and the in-cylinder wireless communication module are fixed on the transformation piston in a high-temperature glue or mechanical connection mode. The power supply voltage stabilizing chip and the peripheral circuit of the power supply voltage stabilizing module, the capacitor acquisition chip and the peripheral circuit of the capacitor acquisition module, the wireless communication chip and the peripheral circuit of the wireless communication module in the cylinder are manufactured into one or more integrated circuit boards, the plurality of circuit boards are electrically connected by using a lead, and the circuit boards, the battery and the temperature control switch are fixed on the inner wall of the skirt part of the reconstructed piston. The following requirements need to be satisfied when mounting the circuit board and the battery: (1) the installation positions of the circuit board and the battery need to be close to the inner wall of the piston skirt as much as possible, so that the circuit board and the battery are ensured not to interfere with the connecting rod when the engine runs; (2) considering that the temperature of the piston is reduced from the top to the bottom and the maximum working temperature limit of electronic components exists, the circuit board and the battery are placed at the position close to the bottom of the inner wall of the modified piston skirt portion as much as possible.

Preferably, the adaptation improvement mode is as follows: and respectively grooving and perforating on the original piston to form the modified piston. Punching a hole at the position of an original piston skirt part point to be measured, installing a capacitance electrode probe to be measured in the hole, enabling the working surface of the capacitance electrode probe to be measured to be flush with the outer wall of the modified piston skirt part, keeping a preset gap between the side surface and the hole, enabling the capacitance electrode probe to be measured to be made of a metal conductor, placing a shielding case in the gap, filling high-temperature-resistant insulating glue, keeping the capacitance electrode probe to be measured, the shielding case and the modified piston to be insulated from each other, and enabling the capacitance electrode probe to be measured and the shielding case to be fixed in the hole. The cylinder sleeve and the capacitance acquisition chip connecting device are connected to the improved piston in a mechanical connection mode.

Preferably, the sliding conductor support frame and the sliding conductor and elastic element connecting piece of the cylinder sleeve and capacitance acquisition chip connecting device are made of high-strength engineering plastics and are insulated from the improved piston and the sliding conductor.

Preferably, the antenna is not integrated in the circuit board, is led out from the circuit board, and is fixed at a proper position on the transformation piston by using high-temperature glue or a mechanical connection mode.

The invention also discloses a telemetering method for measuring the thickness of the oil film between the piston and the cylinder sleeve based on the capacitance method, which is realized based on the telemetering device for measuring the thickness of the oil film between the piston and the cylinder sleeve based on the capacitance method, and the telemetering method comprises the following steps: the modified piston does high-speed reciprocating motion in the cylinder sleeve, the lubrication state between the modified piston and the cylinder sleeve is fluid dynamic pressure lubrication at most positions in the stroke of the modified piston, lubricating oil is filled in a friction pair gap, and the lubricating oil is a non-conductive material, so that a capacitance is formed by the capacitance electrode probe to be measured, the cylinder sleeve and the lubricating oil, and a capacitance value reflecting the thickness change of an oil film between the piston and the cylinder sleeve is measured through a capacitance acquisition chip and a peripheral circuit thereof. The capacitance acquisition module transmits acquired capacitance signals to the in-cylinder wireless communication module, the in-cylinder wireless communication module transmits the capacitance signals to the out-cylinder wireless communication module, the out-cylinder wireless communication module transmits the capacitance signals to the upper computer data processing module for data processing, the oil film thickness of the measuring point is deduced through a parallel plate capacitor formula, and the upper computer data processing module realizes data visualization display and data storage on the oil film thickness data of the measuring point. And bidirectional communication is realized between the in-cylinder wireless communication module and the out-cylinder wireless communication module. The upper computer data processing module sends an instruction, and the instruction is transmitted to the capacitance acquisition chip and the peripheral circuit thereof through the wireless communication module, so that the capacitance acquisition module is controlled.

Preferably, during single-point measurement, the abrasion loss at the measuring point of the modified piston is monitored in real time along with the change of time according to the change of the oil film thickness at the measuring point which is tracked and measured. When in multipoint measurement, the capacitance electrode probes to be measured are arranged on the thrust side and the secondary thrust side of the piston, and the second-order motion condition of the piston is monitored in real time according to the change of the oil film thickness of a measured point which is tracked and measured.

Has the advantages that:

1. the invention discloses a telemetering device and a telemetering method for measuring the thickness of an oil film between a piston and a cylinder sleeve based on a capacitance method.

2. Under traditional measuring piston and the cylinder liner oil film thickness device normal operating condition based on electric capacity method, electric capacity collection module exists a plurality of capacitance electrode probes that await measuring that are located the cylinder liner outside the jar, and the processing of probe mounting hole is inwards punched by the engine outside, owing to need use a plurality of electrode probes to survey the oil film thickness of piston in different positions department, so need beat a plurality of mounting holes from the surface to the cylinder liner at the engine organism. The design of the engine body valve control mode inevitably increases the processing workload, the processing difficulty and the cost. The invention discloses a telemetering device and a method for measuring the thickness of an oil film between a piston and a cylinder sleeve based on a capacitance method.

3. Traditional be based on electric capacity method measurement piston and cylinder liner between diaphragm thickness device when punching to the cylinder liner from the engine organism, owing to need process a plurality of through-holes, can not avoid lining up the water jacket, need consider the sealed problem of every capacitance electrode probe department that awaits measuring this moment, if sealed effect is poor, make water jacket coolant liquid reveal to combustion chamber or oil pan, lead to the combustion effect variation or make the rotten aggravation frictional wear of machine oil, lead to the measuring result inaccurate. The invention discloses a telemetering device and a method for measuring the thickness of an oil film between a piston and a cylinder sleeve based on a capacitance method.

4. The invention discloses a telemetering device and a method for measuring the thickness of an oil film between a piston and a cylinder sleeve based on a capacitance method.

5. The invention discloses a telemetering device and a telemetering method for measuring the thickness of an oil film between a piston and a cylinder sleeve based on a capacitance method.

6. The invention discloses a telemetering device and a telemetering method for measuring the thickness of an oil film between a piston and a cylinder sleeve based on a capacitance method. When in multipoint measurement, the capacitance electrode probe to be measured is arranged on the thrust side and the secondary thrust side of the modified piston, and the second-order motion condition of the piston is monitored in real time according to the thickness change of the oil film at the tracked measuring point.

Drawings

FIG. 1 is a structural frame diagram of a telemetering apparatus for measuring the thickness of an oil film between a piston and a cylinder liner based on a capacitance method, which is disclosed in this embodiment.

Fig. 2 is a three-dimensional diagram of an in-cylinder part installation structure of the telemetering device for measuring the thickness of an oil film between a piston and a cylinder sleeve based on a capacitance method.

Fig. 3 is a schematic structural view of a cylinder liner and a capacitance acquisition chip connection device, fig. 3(a) is a front view, fig. 3(b) is a side view, fig. 3(c) is a top view, and fig. 3(d) is an isometric view.

Fig. 4 is a structural view of the installation of the electrode probe of the capacitor to be measured.

FIG. 5 is a schematic diagram of a telemetry system hardware circuit configuration and a data signal transmission route.

Wherein: 1, a power supply voltage stabilizing module; 1.1-a battery; 1.2-power supply voltage-stabilizing chip and its peripheral circuit; 1.3-temperature control switch; 2-a capacitance acquisition module; 2.1-capacitance acquisition chip and its peripheral circuit; 2.2-capacitance to be measured; 2.2.1-capacitance electrode probe to be measured; 2.2.2-cylinder liner; 2.2.3 lubricating oil; 2.3-cylinder liner and electric capacity gather the chip junction device; 2.3.1 — sliding conductor; 2.3.2 — sliding conductor support; 2.3.3 — an elastic element; 2.3.4-sliding conductor and elastic element connection; 2.3.5-cylinder sleeve collection end conducting wire; 2.4-probe fixing and connecting part; 2.4.1-high temperature insulating glue; 2.4.2-shield cover; 2.4.3-probe acquisition end lead; 3-a wireless communication module; 3.1-in-cylinder wireless communication module; 3.2-an out-of-cylinder wireless communication module; 3.1.1 — wireless communication chip and its peripheral circuit; 3.1.2 — antenna; 4, an upper computer data processing module; 5, modifying the piston.

Detailed Description

The invention will now be described in further detail with reference to the accompanying drawings, which are simplified schematic drawings that illustrate, by way of illustration only, the basic structure and operation of the invention, and thus show only the elements that are relevant to the invention.

Example 1:

as shown in fig. 1 and 2, the telemetering device for measuring the thickness of an oil film between a piston and a cylinder liner based on a capacitance method disclosed in this embodiment includes a power supply voltage stabilizing module 1, a capacitance acquisition module 2, a wireless communication module 3, an upper computer data processing module 4, and a modified piston 5. The wireless communication module 3 uses a Zigbee wireless communication module based on Zigbee wireless communication technology.

The power supply voltage stabilizing module 1 consists of a battery BR2450A1.1, a power supply voltage stabilizing chip Lm1117-3.3, a peripheral circuit 1.2 of the power supply voltage stabilizing chip and a temperature control switch 1.3. Battery BR2450A1.1 is automobile-grade button cell, establishes ties the back with 3 batteries, uses high temperature glue to fix in transformation piston skirt portion inner wall downside, provides 9V mains voltage for telemetering system jar inner circuit. The power supply voltage stabilizing chip Lm1117-3.3 and the peripheral circuit 1.2 thereof output 3.3V voltage after inputting 9V power supply voltage to supply power for the capacitance acquisition chip PCAP01 and the peripheral circuit 2.1 thereof, the wireless communication chip CC2530 and the peripheral circuit 3.1.1 thereof. The type of the temperature control switch KSD97001.3 is a normally open type, and the threshold temperature is 65 ℃. Because the maximum temperature that the temperature control switch KSD97001.3 can bear is higher, the temperature control switch KSD97001.3 is installed at a position on the upper part of the inner wall of the piston compared with the battery or the circuit board.

The capacitance acquisition module 2 comprises a capacitance acquisition chip PCAP01 and a peripheral circuit 2.1 thereof, a capacitor to be detected 2.2, a cylinder sleeve and capacitance acquisition chip connecting device 2.3 and a probe fixing and connecting part 2.4. In the embodiment, the capacitor acquisition chip PCAP01 and the peripheral circuit 2.1 thereof include a capacitor acquisition chip PCAP01 and a main control chip STM32F 103. The main control chip STM32F103 burns programs to the capacitor acquisition chip PCAP01, sets a configuration register of the PCAP01, reads capacitor data measured by the PCAP01 at regular time, and sends the capacitor data to the Zigbee in-cylinder wireless communication module 3.1 through UART serial port communication. The capacitor to be measured 2.2 mainly comprises a capacitor electrode probe to be measured 2.2.1, a cylinder sleeve 2.2.2 and lubricating oil 2.2.3. The two capacitance electrodes of the capacitor to be measured are the capacitance electrode probe 2.2.1 to be measured and the cylinder sleeve 2.2.2, namely, one electrode is the capacitance electrode probe 2.2.1 to be measured fixed on the improved piston 5, and the other electrode is the cylinder sleeve 2.2.2. The capacitance electrode probe 2.2.1 to be measured is made of brass, the shape of the capacitance electrode probe is processed into a cylinder, the diameter of a working surface of the capacitance electrode probe is 3mm, a lead connecting hole is processed at the rear end of the capacitance electrode probe 2.2.1 to be measured, and the diameter of the hole is 0.8 mm. The cylinder sleeve and capacitor acquisition chip connecting device 2.3 mainly comprises a sliding conductor 2.3.1, a sliding conductor support frame 2.3.2, an elastic element 2.3.3, a sliding conductor and elastic element connecting piece 2.3.4 and a cylinder sleeve acquisition end lead 2.3.5. The material of the sliding conductor 2.3.1 is graphite, and the material has good conductivity and self-lubricating property. And 2 metal extension springs are selected as the elastic elements 2.3.3. The material of the sliding conductor support frame 2.3.2 and the sliding conductor and elastic element connecting piece 2.3.4 in the cylinder sleeve and capacitor acquisition chip connecting device 2.3 is high-strength engineering plastic, and the modified piston 5, the sliding conductor 2.3.1 and the elastic element are insulated from each other after the cylinder sleeve and capacitor acquisition chip connecting device 2.3 is installed. The shape of sliding conductor 2.3.1 is the cuboid, and length, width and height are 39mm, 4.9mm, 2mm respectively to at every arris processing radius angle, the radius is 0.5mm, two holes of back half processing at sliding conductor 2.3.1, first hole position is 3mm apart from the rear end face, and second hole position is 8mm apart from the rear end face, and the aperture all is 2 mm. The sliding conductor and elastic element connecting piece 2.3.4 is cylindrical in shape, the diameter is 2mm, the length is 20mm, threads with the depth of 5mm are machined at two ends of the sliding conductor and elastic element connecting piece 2.3.4, the sliding conductor and elastic element connecting piece 2.3.4 penetrates into a second through hole, close to the tail end, of the sliding conductor 2.3.1, and the length of exposed parts at two ends of the sliding conductor and elastic element connecting piece 2.3.4 is kept equal after installation. The bottom plate of the sliding conductor support frame 2.3.2 is a cuboid, four through holes with the diameter of 3mm are processed at four corners close to the bottom plate, a cuboid protruding structure is arranged on the bottom plate, the through holes are processed on the protruding structure, the shape and the size of each through hole are consistent with the cross section of the sliding conductor 2.3.1, the sliding conductor 2.3.1 penetrates into the hole, and the shape and the size of each through hole only allow the sliding conductor 2.3.1 to slide in the hole. Two spring fixed ends are processed on the sliding conductor support frame 2.3.2, one end of one spring is fixed on each spring fixed end, the other ends of the two springs are fixed at two ends of the sliding conductor and elastic element connecting piece 2.3.4 through nuts, and tension is generated on the sliding conductor and the elastic element connecting piece 2.3.4. When the modified piston 5 is fitted into the cylinder liner, the tension of the spring will keep the sliding conductor 2.3.1 and the cylinder liner 2.2.2 in compression and establish an electrical connection. The first through hole of the sliding conductor 2.3.1 near the tail end uses a bolt and a nut to fix one end of the lead wire 2.3.5 at the acquisition end of the cylinder sleeve, and establishes the electrical connection between the sliding conductor 2.3.1 and the lead wire 2.3.5 at the acquisition end of the cylinder sleeve. The other end of the cylinder sleeve acquisition end lead 2.3.5 is electrically connected with a capacitance measurement pin of the capacitance acquisition chip PCAP01 and the peripheral circuit 2.1 thereof in a welding mode. So far, the cylinder sleeve 2.2.2 is electrically connected with the capacitance acquisition chip PCAP01 and the peripheral circuit 2.1 thereof through the cylinder sleeve and capacitance acquisition chip connecting device 2.3. The probe fixing and connecting part 2.4 mainly comprises high-temperature insulating glue 2.4.1, a shielding case 2.4.2 and a probe acquisition end lead 2.4.3. And a shielding case 2.4.2 is placed in the gap, wherein the shielding case 2.4.2 is made of brass, and is cylindrical in shape, 4mm in diameter and 0.2mm in thickness. The lead 2.4.3 of the acquisition end of the probe is inserted into a lead connecting hole at the rear end of the electrode probe 2.2.1 of the capacitor to be tested, the lead 2.4.3 of the acquisition end of the probe is fixed at the rear end of the probe in a welding mode and is electrically connected, and the other end of the lead 2.4.3 of the acquisition end of the probe is connected with a capacitor measurement pin of a capacitor acquisition chip PCAP01 and a peripheral circuit 2.1 thereof in a welding mode.

The Zigbee wireless communication module 3 comprises a Zigbee in-cylinder wireless communication module 3.1 and a Zigbee out-cylinder wireless communication module 3.2, and the Zigbee in-cylinder wireless communication module 3.1 and the Zigbee out-cylinder wireless communication module 3.2 are respectively composed of a wireless communication chip CC2530, a peripheral circuit 3.1.1 and an antenna 3.1.2. The wireless communication chip CC2530 and the peripheral circuit 3.1.1 thereof are integrated into a circuit board independently, the circuit board is two panels, the shape is a cuboid, the length is 30mm, the width is 20mm, and the height is 1.6 mm. The antenna 3.1.2 is not integrated in the circuit board, is fixed on the bottom surface of the skirt part right below the pin hole of the modified piston 5 by using high-temperature glue, and is connected with the wireless communication chip CC2530 and the peripheral circuit 3.1.1 thereof through a lead.

The upper computer data processing module 4 is developed by using Visual Studio, and needs to set upper computer interface arrangement, serial communication, data conversion algorithm, data image display and data storage. The device is used for realizing data visualization display and data storage of the telemetering measurement data, and the telemetering measurement data is a capacitance value reflecting the change of the oil film thickness between the piston and the cylinder sleeve.

The improved piston 5 is a piston which is provided with a capacitance electrode probe 2.2.1 to be tested and a cylinder sleeve and capacitance acquisition chip connecting device 2.3 for adaptive improved processing, and an engine body does not need to be refitted. The modified piston 5 is 150mm in outer diameter and 138.8mm in height. And punching a through hole with the diameter of 5mm at the position of the original piston skirt part point to be measured. The capacitance electrode probe 2.2.1 to be measured is placed in the hole, the working surface of the capacitance electrode probe 2.2.1 to be measured is flush with the outer wall of the skirt part of the improved piston 5, the side surface and the hole are concentric, and the gap is 1 mm. The shielding case 2.4.2 is placed in the gap, the installation position of the shielding case is concentric with the capacitance electrode probe 2.2.1 to be detected, and the gap is filled with the high-temperature-resistant insulating glue 2.4.1, so that the capacitance electrode probe 2.2.1 to be detected and the shielding case 2.4.2 are fixed in the hole, and the capacitance electrode probe 2.2.1 to be detected, the shielding case 2.4.2 and the transformation piston 5 are insulated from each other. 4M 3 threaded holes are processed on the bottom surface of the skirt part (opposite to the antenna fixed position) right below the pin hole of the modified piston 5, and the sliding conductor support frame 2.3.2 in the cylinder sleeve and capacitor acquisition chip connecting device 2.3 is mechanically connected with the modified piston 5 through a screw with the size of M3. The power supply voltage stabilizing chip Lm1117-3.3 and the peripheral circuit 1.2 thereof, the capacitance acquisition chip PCAP01 and the peripheral circuit 2.1 thereof are made into an integrated circuit board which is cuboid and 30mm, 20mm and 1.6mm in length, width and height, and the wireless communication chip CC2530 and the peripheral circuit 3.1.1 thereof are made into an integrated circuit board separately. The two circuit boards are electrically connected by 4 wires, namely a 3.3V power line, a ground wire, a UART transmitting wire and a UART receiving wire. The power supply voltage stabilizing module 1, the capacitor acquisition chip PCAP01 and the peripheral circuit 2.1 thereof, the capacitor electrode probe to be tested 2.2.1, the cylinder sleeve acquisition end lead 2.3.5, the shielding case 2.4.2, the probe acquisition end lead 2.4.3 and the Zigbee in-cylinder wireless communication module 3.1 are fixed on the transformation piston 5 through high-temperature glue. The two circuit boards and the conducting wire are fixed at the bottom of the inner wall of the skirt part of the improved piston 5 by using high-temperature structural adhesive. The temperature control switch KSD97001.3 is fixed on the inner wall of the skirt part of the modified piston 5 by high-temperature structural adhesive, and the position of the temperature control switch KSD97001.3 is slightly higher than that of the circuit board. The battery BR2450A1.1 is fixed on the bottom of the inner wall of the skirt part at the other side of the modified piston 5 by high-temperature structural adhesive.

Before the measurement system runs, each chip and an upper computer need to be programmed, the required programs comprise PCAP01 firmware, STM32 firmware, CC2530 firmware and computer-side upper computer programs, wherein the PCAP01 firmware is burnt by STM32 through SPI serial port communication. The STM32 firmware is to realize SPI initialization, UART initialization, PCAP01 firmware burning, PCAP01 configuration register setting, PCAP01 result register reading and result sending to the CC2530 chip through UART. The CC2530 firmware uses a Zigbee protocol stack frame to realize the functions of UART serial port transceiving and wireless sending. The upper computer program realizes serial port receiving and transmitting, signal conversion and signal visual display and storage.

The embodiment also discloses a telemetering method for measuring the thickness of the oil film between the piston and the cylinder sleeve based on the capacitance method, which is realized based on the telemetering device for measuring the thickness of the oil film between the piston and the cylinder sleeve based on the capacitance method, and the telemetering method comprises the following steps: the improved piston 5 reciprocates at a high speed in the cylinder sleeve, the lubrication state between the improved piston 5 and the cylinder sleeve 2.2.2 is fluid dynamic pressure lubrication at most positions in the stroke of the improved piston 5, the lubricating oil 2.2.3 is filled in a friction pair gap, and the lubricating oil 2.2.3 is a non-conductive material, so that the capacitance electrode probe 2.2.1 to be measured, the cylinder sleeve 2.2.2 and the lubricating oil 2.2.3 form capacitance, and a capacitance value reflecting the thickness change of an oil film between the piston and the cylinder sleeve is measured by a capacitance acquisition chip PCAP01 and a peripheral circuit 2.1 thereof. The capacitance acquisition module 2 transmits acquired capacitance signals to the Zigbee in-cylinder wireless communication module 3.1, the Zigbee in-cylinder wireless communication module 3.1 transmits the capacitance signals to the Zigbee out-cylinder wireless communication module 3.2, the Zigbee out-cylinder wireless communication module 3.2 transmits the capacitance signals to the upper computer data processing module 4 for data processing, the oil film thickness of the measuring point is deduced through a parallel plate capacitor formula, and data visualization display and data storage are realized on the oil film thickness data of the measuring point through the upper computer data processing module 4. And the Zigbee in-cylinder wireless communication module 3.1 and the Zigbee out-cylinder wireless communication module 3.2 realize two-way communication. The upper computer data processing module 4 sends an instruction, and the instruction is transmitted to the capacitance acquisition chip PCAP01 and the peripheral circuit 2.1 thereof through the Zigbee wireless communication module 3, so as to control the capacitance acquisition module 2.

When single-point measurement is carried out, the abrasion loss at the measuring point of the piston 5 is monitored in real time along with the change of time according to the change of the oil film thickness at the measuring point which is tracked and measured. When multi-point measurement is carried out, the capacitance electrode probe 2.2.1 to be measured is arranged on the thrust side and the secondary thrust side of the piston, and the second-order motion condition of the piston is monitored in real time according to the change of the oil film thickness of a measuring point which is tracked and measured.

The above detailed description is provided for the purpose of illustrating the invention, and it should be understood that the present invention is only exemplary and is not intended to limit the scope of the invention, and any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the scope of the present invention.