1. A calibration system of a longitudinal force friction coefficient tester is characterized in that: including track (1), support (2) are installed to the end of track (1), the coupling has push rod (3) in support (2), servo motor (4) are installed to support (2) bottom, install eccentric wheel (5) on the rotation axis of servo motor (4), pressure sensor (10) are installed to the bottom of push rod (3), eccentric wheel (5) contact with pressure sensor (10), contact (6) are installed at the top of push rod (3), contact (6) contact with dynamometry sensor (8) on longitudinal force coefficient of friction tester (7), detachable installs spacer pin (9) on track (1).

2. A system for calibrating a longitudinal force coefficient of friction tester as defined in claim 1, wherein: an expansion rod (11) is installed at the top of the push rod (3), and the contact (6) is installed on the expansion rod (11).

3. The system for calibrating a longitudinal force coefficient of friction tester as recited in claim 2, wherein: the contact (6) comprises a base (12), clamping pieces (13) are hinged to two sides of the base (12), a sliding plate (14) is arranged on the inner sides of the clamping pieces (13) in a sliding mode, and a rubber jacking block (15) is installed on the base plate (12) in a threaded mode.

4. The system for calibrating a longitudinal force coefficient of friction tester as recited in claim 3, wherein: the base (12) is arranged on the telescopic rod (11) through a connecting shaft (16).

5. A method of calibrating a calibration system for a longitudinal force coefficient of friction tester as claimed in any one of claims 1 to 4, comprising the steps of:

A. the limiting pin (9) is disassembled, the longitudinal force friction coefficient tester (7) is moved to the front of the support (2), and a testing wheel of the longitudinal force friction coefficient tester (7) is positioned on the track (1);

B. inserting the push rod into a longitudinal force friction coefficient tester (7) to enable the contact (6) to be in contact with the force measuring sensor (8);

C. reinstalling the limiting pin (9) to enable the limiting pin (9) to be in compression joint with the longitudinal force friction coefficient tester (7);

D. starting the servo motor (4), driving the eccentric wheel (5) to rotate by a rotating shaft of the servo motor (4), so that the eccentric wheel (5) extrudes the push rod (3), and synchronously measuring extrusion force by the pressure sensor (10);

E. converting the stress of the force measuring sensor (8) according to the force application of the servo motor (4) to the push rod (3) and the length of force arms at two ends of the push rod, and calibrating the detection value of the force measuring sensor (8) according to the converted stress;

F. when the deviation between the force application magnitude of the push rod (3) by the servo motor (4) and the detection value of the pressure sensor (10) exceeds a preset threshold value, a calculation function of the force application of the servo motor and/or the pressure sensor (10) is calibrated.

Background

The longitudinal force friction coefficient refers to the ratio of the longitudinal resistance of the test wheel generated between the test special tire and a wet road surface under the condition of complete braking or incomplete braking to the vertical load acting on the ground when the test wheel keeping the same direction with the advancing direction of the vehicle runs at a certain speed. The longitudinal resistance is measured by a load cell, the magnitude of which is proportional to the coefficient of friction between the road surface and the tire. The braking force tester mainly comprises a bearing vehicle or a tractor, a force transducer, a vertical load device, a distance testing device, a temperature testing device, a water supply device, a computer control system and the like, wherein the accuracy of longitudinal resistance detection of the force transducer directly influences the detection precision of the longitudinal force friction coefficient, so that the force transducer needs to be calibrated regularly. In the prior art, during calibration, the load cell needs to be detached from a test vehicle and mounted on a pressure calibration device for calibration. However, the force sensor may be disturbed during the mounting and dismounting process, which may affect the calibration effect.

Disclosure of Invention

The invention aims to provide a calibration system and a calibration method for a longitudinal force friction coefficient tester, which can overcome the defects of the prior art, can calibrate a force sensor without disassembling the force sensor and have high calibration precision.

In order to solve the technical problems, the technical scheme adopted by the invention is as follows.

The utility model provides a calibration system of longitudinal force coefficient of friction tester, includes the track, and the support is installed to orbital end, and the coupling has the push rod on the support, and servo motor is installed to the support bottom, installs the eccentric wheel on servo motor's the rotation axis, and pressure sensor is installed to the bottom of push rod, and the eccentric wheel contacts with pressure sensor, and the contact is installed at the top of push rod, and the contact contacts with the dynamometry sensor on the longitudinal force coefficient of friction tester, and detachable installs the spacer pin on the track.

Preferably, the top of the push rod is provided with a telescopic rod, and the contact is arranged on the telescopic rod.

Preferably, the contact includes the base, and the base both sides are articulated to have the clamping piece, and the inboard slip of clamping piece is provided with the slide, and threaded mounting has the rubber kicking block on the base plate.

Preferably, the base is mounted on the telescopic rod through a connecting shaft.

A calibration method of the calibration system of the longitudinal force friction coefficient tester comprises the following steps:

A. the limiting pin is disassembled, the longitudinal force friction coefficient tester is moved to the front of the support, and a testing wheel of the longitudinal force friction coefficient tester is positioned on the track;

B. inserting the push rod into a longitudinal force friction coefficient tester to enable the contact to be in contact with the force transducer;

C. reinstalling the limiting pin to enable the limiting pin to be in compression joint with the longitudinal force friction coefficient tester;

D. starting a servo motor, driving an eccentric wheel to rotate by a rotating shaft of the servo motor, enabling the eccentric wheel to extrude a push rod, and synchronously measuring extrusion force by a pressure sensor;

E. converting the stress of the force sensor according to the force application of the servo motor to the push rod and the length of force arms at two ends of the push rod, and calibrating the detection value of the force sensor according to the converted stress;

F. and when the deviation between the force application size of the push rod by the servo motor and the detection value of the pressure sensor exceeds a preset threshold value, calibrating a calculation function of the force application of the servo motor and/or the pressure sensor.

Adopt the beneficial effect that above-mentioned technical scheme brought to lie in: the invention can realize the direct calibration of the force transducer on the longitudinal force friction coefficient tester without disassembling the longitudinal force friction coefficient tester. The telescopic rod is used for adjusting the height position of the contact, and the contact and the force measuring sensor are convenient to mount and fix. When the contact is connected with the force transducer, the clamping piece is clamped outside the force transducer, and the sliding plate is in contact with the force transducer, so that the contact and the force transducer can generate relative displacement only in the sliding direction of the sliding plate, and the contact stability of the contact and the force transducer is improved. The contact is movably mounted through the connecting shaft, and angle change of the push rod during calibration can be effectively adapted. Meanwhile, the calibration system carries out synchronous self-checking on the calibration process through the pressure sensor, and can find out the error in time when the calibration system has the error, so that the calibration error caused by the problem of the calibration system can be avoided.

Drawings

FIG. 1 is a block diagram of one embodiment of the present invention.

Figure 2 is a top view of a contact in accordance with an embodiment of the present invention.

In the figure: 1. a track; 2. a support; 3. a push rod; 4. a servo motor; 5. an eccentric wheel; 6. a contact; 7. a longitudinal force friction coefficient tester; 8. a force sensor; 9. a spacing pin; 10. a pressure sensor; 11. a telescopic rod; 12. a substrate; 13. a clip; 14. a slide plate; 15. a rubber top block; 16. and (7) connecting the shafts.

Detailed Description

The standard parts used in the invention can be purchased from the market, the special-shaped parts can be customized according to the description and the description of the attached drawings, and the specific connection mode of each part adopts the conventional means of mature bolts, rivets, welding, sticking and the like in the prior art, and the detailed description is not repeated.

Referring to fig. 1-2, a specific embodiment of the present invention includes a rail 1, a bracket 2 is installed at the end of the rail 1, a push rod 3 is coupled to the bracket 2, a servo motor 4 is installed at the bottom of the bracket 2, an eccentric wheel 5 is installed on a rotating shaft of the servo motor 4, a pressure sensor 10 is installed at the bottom end of the push rod 3, the eccentric wheel 5 is in contact with the pressure sensor 10, a contact 6 is installed at the top of the push rod 3, the contact 6 is in contact with a force sensor 8 on a longitudinal force friction coefficient tester 7, and a limit pin 9 is detachably installed on the rail 1. The top of the push rod 3 is provided with an expansion link 11, and the contact 6 is arranged on the expansion link 11. The contact 6 comprises a base 12, clamping pieces 13 are hinged to two sides of the base 12, sliding plates 14 are arranged on the inner sides of the clamping pieces 13 in a sliding mode, and rubber jacking blocks 15 are installed on the base plate 12 in a threaded mode. The base 12 is mounted on the telescopic rod 11 by means of a connecting shaft 16.

A calibration method of the calibration system of the longitudinal force friction coefficient tester comprises the following steps:

A. the limiting pin 9 is disassembled, the longitudinal force friction coefficient tester 7 is moved to the front of the support 2, and the testing wheel of the longitudinal force friction coefficient tester 7 is positioned on the track 1;

B. inserting the push rod into a longitudinal force friction coefficient tester 7 to enable the contact 6 to be in contact with a force measuring sensor 8;

C. reinstalling the limit pin 9, and enabling the limit pin 9 to be in pressure connection with the longitudinal force friction coefficient tester 7;

D. starting the servo motor 4, driving the eccentric wheel 5 to rotate by a rotating shaft of the servo motor 4, enabling the eccentric wheel 5 to extrude the push rod 3, and synchronously measuring the extrusion force by the pressure sensor 10;

E. converting the stress of the force sensor 8 according to the force applied by the servo motor 4 to the push rod 3 and the length of the force arms at the two ends of the push rod, and calibrating the detection value of the force sensor 8 according to the converted stress;

F. when the deviation between the force application magnitude of the push rod 3 by the servo motor 4 and the detection value of the pressure sensor 10 exceeds a preset threshold value, the calculation function of the force application of the servo motor and/or the pressure sensor 10 is calibrated.

In the description of the present invention, it is to be understood that the terms "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on those shown in the drawings, are merely for convenience of description of the present invention, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the present invention.

The foregoing shows and describes the general principles and broad features of the present invention and advantages thereof. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.