1. Hang agricultural implement operating resistance and measure sensing device, including force transducer and by the measuring circuit of force transducer structure, characterized by: three force sensors (3), (5) and (7) are pin shaft type strain two-way radial force sensors which are respectively arranged on a U-shaped upper suspension lug (6) and two lower U-shaped suspension lugs (4) and (8) at the left and right of a suspended agricultural implement; each U-shaped suspension lug is provided with a small and a large two directional and limiting screw holes (10) and (11), the central connecting line of the two limiting screw holes is parallel to the horizontal reference surface of the frame of the agricultural implement, and each pin shaft sensor is fixed on the U-shaped suspension lug by a bolt to prevent the pin shaft sensor from rotating in the circumferential direction and moving in the axial direction; each pin sensor can measure radial component forces in the X direction and the Y direction; the three pin shaft sensors have the same structural parameters, strain gauge resistance values and X and Y direction sensitivity parameters.

2. The sensing device for measuring the operating resistance of a suspended agricultural implement according to claim 1, wherein: one end of the pin shaft type strain two-way radial force sensor is provided with a pin shaft head (101) with the diameter larger than that of a pin shaft cylinder, two positioning notches (102) and (104) which are one small and one large are symmetrically arranged on the outer edge of the pin shaft head at an interval of 180 degrees, and the pin shaft sensor is fixed on two corresponding directional and limiting screw holes (10) and (11) on a U-shaped hanging lug of an agricultural implement through the two positioning notches by bolts so as to limit the circumferential rotation and the axial movement of the pin shaft sensor.

3. The sensing device for measuring the operating resistance of a suspended agricultural implement according to claim 1, wherein: the pin shaft type strain two-way radial force sensor is provided with a left annular groove (110) and a right annular groove (111) along the circumference at two ends close to the pin shaft; 4 lead grooves (130) are axially formed in the cylindrical surface of the pin shaft at intervals of 90 degrees, the positions of the lead grooves on the circumference are staggered with two positioning notches (102) and (104) by +/-45 degrees, and 4 threading through holes (103) are correspondingly formed in the end surface of the pin shaft head (101) and used for leading out a measurement lead.

4. The sensing device for measuring the operating resistance of a suspended agricultural implement according to claim 1, wherein: the pin shaft type strain two-way radial force sensor is characterized in that 4 uniaxial strain gages are adhered to each annular groove surface of a pin shaft at intervals of 90 degrees in the circumferential direction, the 4 strain gages are opposite in pairs, wherein R2 is opposite to R4, R6 is opposite to R8 and corresponds to the positions of two positioning notches in the outer edge of the pin shaft head, R1 is opposite to R3, R5 is opposite to R7, and the circumferential position of the sensor is 90 degrees staggered from the two positioning notches in the outer edge of the pin shaft head; the longitudinal axis of each strain gauge on the two ring grooves and the cylinder surface prime line of the ring groove form an angle of +/-45 degrees; 8 strain gages are connected in sequence to form two full-bridge measuring circuits, wherein four strain gages of R1 and R3 on the left annular groove and R5 and R7 on the right annular groove are connected in sequence of R1-R3-R7-R5 to form a full-bridge measuring circuit (803) of X-direction radial component force, four strain gages of R2 and R4 on the left annular groove and R6 and R8 on the right annular groove are connected in sequence of R2-R4-R8-R6 to form a full-bridge measuring circuit (804) of Y-direction radial component force, and the magnitude and direction angle of radial resultant force applied to the pin sensor are obtained according to the force synthesis principle by the output component force of the X and Y two groups of bridges.

5. The sensing device for measuring the operating resistance of a suspended agricultural implement according to claims 1 to 4, characterized by the following: the measuring circuit constructed by the force sensors is formed by connecting three pin shaft type strain two-way radial force sensor X-direction measuring bridges 803 in parallel according to the sequence of a graph (6), namely, the three pin shaft type strain two-way radial force sensor measuring bridge circuits A, B, C, D are respectively connected, namely, the three pin shaft type strain two-way radial force sensor measuring bridges A, B, C, D are respectively connected, and an X-direction total component force measuring bridge circuit of the whole agricultural implement is constructed; the Y-direction measuring bridges 804 of the three pin shaft sensors are connected in parallel in sequence according to the figure (7) to form a Y-direction total component force measuring bridge circuit of the agricultural implement; the output of the X and Y total component force measuring bridge can obtain the magnitude and direction angle of the operation resistance of the tractor rear-mounted agricultural implement according to the force synthesis principle.

Background

The operating resistance of the agricultural implement is an important parameter when the novel agricultural implement is researched and developed and matched with the power model selection of the agricultural implement. If the change of the operation resistance can be dynamically monitored and mastered in real time in the operation of the agricultural implement, the intelligent control method has practical significance for improving the operation quality and realizing the intelligent control of the operation quality. At present, most of non-self-propelled field operation machines are suspension type agricultural machines, a standardized three-point type hydraulic suspension mechanism is configured on a tractor, the agricultural machines are in three-point suspension connection with the tail ends of an upper pull rod and a lower pull rod of the hydraulic suspension mechanism of the tractor through three suspension points on a rack, when the hydraulic suspension mechanism of the tractor is put down, the agricultural machines fall to the ground, working parts enter the soil, a towing machine pulls the agricultural machines to move forwards for operation, when the hydraulic suspension mechanism of the tractor is lifted up, the agricultural machines are lifted up, and the machine set transfers or transports in the field. Three hitching lugs on a frame of the agricultural implement are connected with ball hinges at the tail ends of an upper pull rod and a lower pull rod of a hydraulic suspension mechanism of the tractor through pin shafts to transmit lifting, pressing and traction force; the other is to replace three common connecting pin shafts with three pin shaft type sensors and then to cooperate with a tilt angle sensor and the like to measure the operation resistance, and the other is to add five pull pressure sensors on an upper pull rod, two lower pull rods and two lower pull rod lifting arms of a tractor suspension device to measure; the above measuring devices have complicated structures, and require more than three sensors to measure each sensor and perform a complicated force calculation process to obtain the operating resistance value. Therefore, it is necessary to develop a simple and easy method for measuring the operating resistance of agricultural machinery and a sensing device, so as to meet the requirements of production and test detection.

Disclosure of Invention

Aiming at the problems, the invention discloses a sensing device for measuring the operation resistance of a suspended agricultural implement, which adopts the technical scheme that: three pin shaft type radial two-way force sensors are arranged on an upper U-shaped suspension lug and two lower U-shaped suspension lugs of a suspended agricultural implement, the pin shaft sensors and the U-shaped suspension lugs are designed in a specific structure, the pin shaft sensors are resistance strain type force sensors, the three pin shaft sensors are connected with a bridge circuit through ingenious ground fabric pieces, the three pin shaft sensors respectively sense the component forces in the X direction and the Y direction on the three U-shaped suspension lugs of the agricultural implement, only the three pin shaft type force sensors are used for respectively detecting the radial component forces in the X direction and the Y direction on the three U-shaped suspension lugs of the agricultural implement, and the magnitude and the direction of the total resistance force during the operation of the whole suspended agricultural implement can be accurately measured according to the force synthesis principle.

Drawings

FIG. 1 is a schematic elevation view of a three-point hitch agricultural implement of a tractor;

FIG. 2 is a schematic top view of a three point hitch agricultural implement of the tractor;

FIG. 3 is a schematic view of three U-shaped suspension lugs and positioning limit screw holes on an agricultural implement;

FIG. 4 is a schematic diagram of a pin-axis strain radial bi-directional force sensor configuration;

FIG. 5 is a schematic diagram of the X-direction and Y-direction strain gauges connected into a bridge measurement circuit, disclosing the bridging connection sequence of the strain gauges;

FIG. 6 is a circuit diagram for measuring total component force in X direction of three pin force sensors

FIG. 7 is a circuit diagram for measuring total component force in Y direction of three pin shaft force sensors

In fig. 1 to 7, the following symbols are used: 1-upper pull rod of tractor suspension device, 2-right lower pull rod of tractor suspension device, 3, 5 and 7-pin shaft type force sensor, 4, 6 and 8-U-shaped suspension ear on farm machinery frame, 9-left lower pull rod of tractor suspension device, small screw hole for orientation and limitation on 10-U-shaped suspension ear, large screw hole for orientation and limitation on 11-U-shaped suspension ear, 101-pin head, small notch for limitation and orientation on 102-pin head, 103-lead wire through hole on pin head, large notch for limitation and orientation on 104-pin head, 110-left ring groove of pin shaft, 111-right ring groove of pin shaft, 112-limit pin hole of pin shaft, 130-axial lead wire groove, 4 strain gauges pasted on R1-R4-left ring groove, 4 strain gauges pasted on R5-R8-right ring groove, the full-bridge measuring circuit for 803-X direction radial component force, the full-bridge measuring circuit for 804-Y direction radial component force, A, B, C and D-are respectively 4 nodes of the bridge circuit.

Detailed Description

Specific embodiments and descriptions of the present invention are provided below in conjunction with the appended drawings:

the sensor for measuring the working resistance of suspended agricultural implement includes force sensor and measuring circuit constituted by the force sensor. 1-3, force sensors 3, 5 and 7 are only pin shaft type strain radial two-way force sensors, and are respectively arranged on a U-shaped suspension lug 6 and a left lower U-shaped suspension lug 4 and a right lower U-shaped suspension lug 8 of a suspended agricultural implement to replace the original suspension pin shaft, wherein the specific structure of the force sensors is shown in FIG. 4; each U-shaped suspension lug is provided with 1 small, 1 large and 2 directional and limiting screw holes 10 and 11, the central connecting line of the two limiting screw holes is parallel to the horizontal reference surface of the frame of the agricultural implement, and the pin shaft force sensor is fixed on the U-shaped suspension lug by a bolt to prevent the pin shaft force sensor from rotating in the circumferential direction and moving in the axial direction; each pin sensor can measure radial component forces in the X direction and the Y direction; the three pin shaft sensors have the same structural parameters, strain gauge resistance values and X and Y direction sensitivity coefficients.

Referring to fig. 4, one end of the pin shaft type strain two-way radial force sensor of the present invention is provided with a pin shaft head 101 with a diameter larger than the diameter of a pin shaft cylinder, the outer edge of the pin shaft head is symmetrically provided with 1 small and 1 large 2 positioning and orientation notches 102 and 104 at an interval of 180 degrees, correspondingly, the U-shaped suspension lifting lug of an agricultural implement is provided with 2 positioning and limiting screw holes 10 and 11, and the pin shaft sensor is fixed on the U-shaped suspension lifting lug of the agricultural implement by bolts through the 2 positioning notches so as to limit circumferential rotation and axial movement of the pin shaft sensor.

As shown in fig. 4, a left annular groove 110 and a right annular groove 111 are formed on the cylindrical surface of the pin shaft near the two ends of the pin shaft; 4 lead grooves 130 are axially formed in the cylindrical surface of the pin shaft at intervals of 90 degrees, and the forming angles of the lead grooves on the circumference are staggered from the 2 positioning notches 102 and 104 by +/-45 degrees; and 4 lead through holes 103 are correspondingly formed in the end surface of the pin head 101 and used for leading out measurement leads.

As shown in fig. 4 and 5, 4 uniaxial strain gauges are adhered to each annular groove of the pin shaft at intervals of 90 degrees in the circumferential direction, R1-R4 are adhered to the left annular groove, R5-R8 are adhered to the right annular groove, the 4 strain gauges on each annular groove are opposite in pairs, wherein R2 is opposite to R4, R6 is opposite to R8, and the circumferential position of each strain gauge is consistent with 2 positioning notches on the outer edge of the pin shaft head; r1 is opposite to R3, R5 is opposite to R7, and the circumferential position is staggered by 90 degrees with 2 positioning notches on the outer edge of the pin head; the longitudinal axis of each strain gauge and the cylinder surface line of the annular groove form an angle of +/-45 degrees; 8 strain gages are connected in sequence to form 2 full-bridge measuring circuits, wherein four strain gages of R1 and R3 on the left annular groove 110 and R5 and R7 on the right annular groove 111 are connected in sequence of R1-R3-R7-R5 to form a full-bridge measuring circuit 803 of radial component force in the X direction, four strain gages of R2 and R4 on the left annular groove 110 and four strain gages of R6 and R8 on the right annular groove 110 are connected in sequence of R2-R4-R8-R6 to form a full-bridge measuring circuit 804 of radial component force in the Y direction, and two groups of bridge measuring circuits of X, Y measure radial component force in the pin X, Y direction respectively.

As shown in fig. 6 and 7, the sensor measuring circuit is constructed as follows: the X-direction measuring bridge circuits 803 of the 3 pin shaft type force sensors are connected in parallel according to the graph of FIG. 6, namely, the A, B, C, D points of the 3 pin shaft type force sensor measuring bridges are respectively connected, namely, the A, B, C, D points of the 3 pin shaft type force sensor measuring bridges are respectively connected to form an X-direction total force dividing measuring bridge circuit of the whole agricultural implement; the Y-direction measuring bridges 804 of the 3 pin shaft sensors are connected in parallel according to the sequence of the figure 7, and are constructed to form a Y-direction total component force measuring bridge of the agricultural implement; the output of the X and Y total component force measuring bridge can obtain the magnitude and direction angle of the operation resistance of the tractor rear-mounted agricultural implement according to the force synthesis principle.