A real-time detection instrument for the slip rate of a roller reaction type automobile brake test bench

Abstract

The present invention relates to a real-time detector for the slip rate of a roller reaction-force automobile brake test bench, comprising a roller meter wheel, a frequency signal transmitter, a USB3200N analog signal acquisition card, a code disc mounting bracket, and a coupling claw between the code disc bracket and the third roller swing support arm. The code disc bracket is tightly connected to the third roller swing support arm through the coupling claw of the code disc bracket, and the code disc bracket is installed on the coupling claw of the code disc bracket, so that the encoder on the roller meter wheel that can measure the roller linear speed can measure the real-time speed of the third roller, convert the speed into a pulse signal, and input it into the USB3200N analog signal acquisition card through the frequency signal transmitter, and finally upload it to the computer. The advantages of this detector are: a real-time slip rate curve can be obtained, and data acquisition is automatically terminated when the drive motor stops, so that the instantaneous slip rate when it stops can be obtained, and the structure is simple, economical and efficient.

Description

Technical Field

[0001] The invention relates to a roller reaction force type automobile brake test bench slip rate real-time detector, which can generate a curve of the instantaneous slip rate in the detection process on a computer so as to achieve the purpose of precise control. Background Art

[0002] At present, the most common vehicle brake testing mechanism in China is the roller reaction brake test bench, which detects the maximum braking force of the wheel by using a third roller to measure the slip rate. When the slip rate reaches the critical slip rate value, the braking force value at this time is taken as the maximum braking force.

[0003] The roller drive device drives the front and rear rollers to rotate, and the front and rear rollers drive the wheels to rotate, and the wheels drive the third roller to rotate. The speed at this time is recorded as v1, so the speed of the third roller is the speed of the wheel. When the brake pedal is stepped on, the speed of the wheel drops instantly, and the speed of the third roller also drops at the same time. The speed at this time is recorded as v2. The speed of the front and rear rollers of the brake platform remains unchanged at v1, and the slip rate is S = (v1-v2) / v1. Because the method of the third roller controlling the automatic shutdown of the drive motor will lead to great uncertainty, and the real-time requirements of the control process are high, it often causes control delays, causing the motor to stop too late. Therefore, the tire under inspection will inevitably have a certain degree of peeling, and the tire life will be greatly shortened; at the same time, the drive motor will also be damaged. Therefore, there is an urgent need for a roller reaction brake test bench tester that can detect the slip rate in real time. Summary of the invention

[0004] The present invention mainly aims at the problem of low real-time slip rate detection accuracy of common roller reaction type automobile brake test bench slip rate detector, and provides a roller reaction type automobile brake test bench real-time slip rate detector with simple structure and simple operation.

[0005] The technical solution adopted by the present invention is described as follows in conjunction with the accompanying drawings:

[0006] A roller reaction force type automobile brake test bench slip rate real-time detector, comprising: a third roller 4, a brake bench front roller 5, a brake bench rear roller 6, a roller type meter wheel 1 and an encoder 14, wherein the third roller 4 is arranged in parallel with the brake bench front roller 5 and the brake bench rear roller 6 respectively, the brake bench front roller 5 and the brake bench rear roller 6 are connected by a chain 2, the brake bench rear roller 6 is driven by a drive motor 8 to drive the brake bench front roller 5 to rotate synchronously, the encoder 14 is fixed on the code disc support swing arm 12, the code disc swing arm support shaft 16 and the code disc swing arm support shaft 16 are connected to the code disc swing arm support shaft 16 and the code disc swing arm support shaft 16. The disc mounting bracket 7 is bolted, and two roller meter wheels 1 are fixed on the third roller swing support arm 3 through the code disc bracket 7 to respectively measure the speed of the third roller contacted by the left and right wheels of the car, and the compression speed measuring wheel spring 9 fixed on the code disc support swing arm 12 is used to ensure that the roller meter wheel 1 is tightly fitted on the third roller 4 during the measurement process; the measured speed is converted into an NPN incremental pulse signal through the encoder 14 on the meter wheel 1, and is input into the USB3200N analog signal acquisition card 24 via the frequency signal transmitter, and finally uploaded to the computer.

[0007] Furthermore, libview is used for programming on the computer. When the program starts running, the data acquisition card does not start collecting data. A conditional trigger is set in the program. When the brake pedal is pressed, data collection officially starts. During the data collection process, a real-time slip rate curve is displayed on the computer. The signal for the end of data collection is sent at the instant when the brake roller drive motor 8 stops working. When the program ends, the slip rate measured during the process is generated into a document.

[0008] Furthermore, the code disc mounting bracket 7 is installed on the T-slot nut guide rail 11 of the code disc bracket connecting claw 17 by means of bolts 10, and the bolts 10 are tightened to make it slide laterally along the T-slot nut guide rail 11 and be fixed, and then the code disc bracket connecting claw 17 is fixed to the third roller swing support arm 3 by means of a top screw 18.

[0009] Furthermore, the two roller meter wheels 1 are connected in the same way, and are powered by a 24V switching power supply to ensure the normal operation of the encoder 14. The signal output terminal 20 in the encoder terminal 15 is connected to the frequency signal transmitter signal receiving terminal 21, and another frequency signal transmitter signal receiving terminal 23 is additionally connected to a 2K resistor 28 in series with the positive pole 27 of the power supply, and another frequency signal transmitter signal receiving terminal 23 of the frequency signal transmitter 22 is connected to the negative pole 19 of the power supply.

[0010] Furthermore, the frequency signal transmitter 22 is also powered by a 24V switching power supply, the positive output terminal 29 is connected to the analog signal input terminal AI031 of the USB3200N analog signal acquisition card 24, and the negative output terminal 30 is connected to the analog signal input terminal AGND32.

[0011] Furthermore, the switch II26 controlled by the brake pedal signal is connected in series with the resistor 2K, and the two are connected in parallel with the 80K resistor, powered by a 5V switching power supply, and its overall positive pole is connected to the digital circuit input terminal PFI135 of the USB3200N analog signal acquisition card 24, and its negative pole is connected to the digital circuit input terminal DGND36 of the USB3200N analog signal acquisition card 24.

[0012] Furthermore, the switch Ⅰ25 controlled by the drive motor stop signal is connected in series with the resistor 2K, and the two are connected in parallel with the 80K resistor, and powered by a 5V switching power supply. The positive pole of the whole is connected to the digital circuit input terminal PFI034 of the USB3200N analog signal acquisition card 24, and the negative pole is connected to the digital circuit input terminal DGND33 of the USB3200N analog signal acquisition card 24.

[0013] Furthermore, through the USB3200N analog signal acquisition card 24, the signal indicating the end of data acquisition is sent out at the instant when the brake roller drive motor 8 stops working. The equipment for data acquisition and control of acquisition stop is the same USB3200N analog signal acquisition card, and the two are performed in one program to ensure the accuracy of the data.

[0014] Furthermore, the roller meter wheel 1 is closely connected to the third roller 4 through the code disc bracket 7 and the third roller swing support arm connecting claw, and the roller meter wheel 1 is moved laterally, which makes the speed of the third roller 4 measured accurately and the structure flexible.

[0015] Furthermore, the pulse of the roller meter wheel 1 is 1000P, and the circumference of the wheel is 200mm.

[0016] The technical effect of the present invention is that a real-time slip rate curve can be obtained, and when the driving motor stops, the data acquisition card automatically stops collecting data, and the collected data is stored in a document for subsequent data processing. At the same time, the structure is simple, economical and efficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the present invention after installation;

[0018] Figure 2 It is a schematic diagram of the roller meter wheel of the present invention being fixed on the third rolling swing support arm through the code disc bracket and the third roller swing support arm connecting claw;

[0019] Figure 3 The circuit diagram of the encoder on the roller meter wheel of the present invention is connected to the USB3200N analog signal acquisition card via the frequency signal transmitter; the circuit diagram of the brake pedal signal controlling the start of data acquisition; the circuit diagram of the drive motor stopping controlling the end of data acquisition;

[0020] In the figure: 1. Roller meter wheel, 2. Chain, 3. Third roller swing support arm, 4. Third roller, 5. Brake platform front roller, 6. Brake platform rear roller, 7. Code disk mounting bracket, 8. Drive motor, 9. Press speed wheel spring, 10. Bolt, 11. T-slot nut guide rail, 12. Code disk support swing arm, 13. Bolt, 14. Encoder, 15. Encoder terminal, 16. Code disk swing arm support shaft, 17. Code disk bracket coupling claw, 18. Top screw, 19. 24V switch power supply positive pole, 20. Encoder signal output terminal, 21. Frequency signal transmitter signal receiving terminal, 22 .Frequency signal transmitter, 23. Another frequency signal transmitter signal receiving end, 24.USB3200N analog signal acquisition card, 25.Switch I, 26.Switch II, 27.24V switching power supply negative pole, 28.2K resistor, 29.Frequency signal transmitter voltage positive output end, 30.Frequency signal transmitter voltage negative output end, 31.USB3200N analog signal acquisition card AI0 port, 32.Acquisition card AGND port, 33Acquisition card DGND port, 34.Acquisition card PFI0 port, 35Acquisition card PFI1 port, 36.Acquisition card DGND port DETAILED DESCRIPTION

[0021] The present invention is described in detail below in conjunction with the accompanying drawings:

[0022] See also Figure 1 , Figure 2 A roller reaction type automobile brake test bench slip rate real-time detector includes a roller meter wheel 1, an encoder 14, a code disc mounting bracket 7, a code disc bracket and a third roller swing support arm connecting claw 17, and a top screw 18. The roller rubber ring with a circumference of 200 mm on the roller meter wheel 1 is bolted to the encoder 14, so that the encoder 14 can receive the speed signal of the third roller 4.

[0023] The encoder 14 is connected and fixed to the code disc support swing arm 12 by bolts 13, and the code disc swing arm support shaft 16 is bolted to the code disc mounting bracket 7. The compression speed wheel spring 9 fixed to the code disc support swing arm 12 can make the roller meter wheel 1 fit closely to the third roller 4 during the measurement process.

[0024] The code disc mounting bracket 7 is fixed to the T-slot nut guide rail 14 of the code disc bracket connecting claw 17 by two bolts 10. By loosening and tightening the bolts 10, the code disc bracket connecting claw 17 can be slid laterally along the T-slot nut guide rail 11, and then the code disc bracket connecting claw 17 is fixed to the third roller swing support arm 3 by the top screw 18.

[0025] See also Figure 3The roller meter wheel 1 is powered by a 24V switching power supply to ensure the normal operation of the encoder 14. The signal output terminal 20 in the encoder terminal 15 is connected to the frequency signal transmitter signal receiving terminal 21. Another frequency signal transmitter signal receiving terminal 23 is additionally connected to a 2K resistor 28 in series with the positive pole 27 of the power supply. Another frequency signal transmitter signal receiving terminal 23 is connected to the negative pole 19 of the power supply.

[0026] The frequency signal transmitter 22 is also powered by a 24V switching power supply, the positive output terminal 29 is connected to the analog signal input terminal AI031 of the USB3200N analog signal acquisition card 24, and the negative output terminal 30 is connected to the analog signal input terminal AGND32. The second meter wheel is wired in the same way.

[0027] The switch II 26 controlled by the brake pedal signal is connected in series with the resistor 2K, and the two are connected in parallel with the 80K resistor and powered by a 5V switching power supply. The positive pole of the whole is connected to the digital circuit input terminal PFI135 of the USB3200N analog signal acquisition card 24, and the negative pole is connected to the digital circuit input terminal DGND36 of the USB3200N analog signal acquisition card 24.

[0028] The switch Ⅰ25 controlled by the drive motor stop signal is connected in series with the resistor 2K, and the two are connected in parallel with the 80K resistor and powered by a 5V switching power supply. The positive pole of the whole is connected to the digital circuit input terminal PFI034 of the USB3200N analog signal acquisition card 24, and the negative pole is connected to the digital circuit input terminal DGND33 of the USB3200N analog signal acquisition card 24.

[0029] Working principle of the roller reaction type automobile brake test bench slip rate real-time detector:

[0030] The driving motor 8 is running to rotate the rear roller 6 of the brake platform, and the rear roller 6 of the brake platform drives the front roller 5 of the brake platform to rotate via the chain 2. The brake platform rollers 5 and 6 drive the wheels to rotate, and the wheels drive the third roller 4 to rotate. The speed at this time is recorded as v1, so the speed of the third roller 4 is the speed of the wheel. When the brake pedal is stepped on, the speed of the wheel drops instantly, and the speed of the third roller 4 also drops at the same time. The speed at this time is recorded as v2, and the speed of the brake platform rollers 5 and 6 remains unchanged at v1, and the slip rate is S=(v1-v2) / v1. The speed of the third roller 4 is measured by the roller meter wheel 1. The pulse of the roller meter wheel encoder 14 is 1000P, and the circumference of the wheel is 200mm. The definition of pulse 1000P is that the wheel can emit 1000 pulses after one rotation. At the same time, the pulse frequency is how many pulses are emitted per second. The frequency signal transmitter 22 can convert the pulse frequency into voltage. The frequency range of the frequency signal transmitter 22 selected by the present invention is 0-5KHz, and the voltage range is 0-10V. The input frequency is output as voltage in a linearly changing manner, input into the USB3200N analog signal acquisition card 24, and finally uploaded to the computer. The program is processed using libview on the computer. When the program starts, the data acquisition card does not start to collect data. A digital edge rising trigger condition is set in it. Only when the brake pedal is stepped on, its signal will close the switch II 26, so that the PFI136 and GDND36 digital circuits change from low level to high level, meet the trigger condition, and start collecting data. Through programming, the voltage input into the analog signal acquisition card is converted into slip rate, and then a real-time slip rate curve is generated and the slip rate is recorded. The drive motor 8 shutdown control switch I 25 is closed, and it is set as a stop condition in the program. Therefore, when the drive motor stops, the entire slip rate acquisition process stops, ensuring that the slip rate of the drive motor 8 at the moment of stopping can be obtained, and the slip rate measured in the entire process is generated into a file.

Claims

1. A roller reaction type automobile brake test bench slip rate real-time detector, comprising: The invention relates to a third roller (4), a brake platform front roller (5), a brake platform rear roller (6), a roller type meter wheel (1) and an encoder (14), characterized in that the third roller (4) is arranged in parallel with the brake platform front roller (5) and the brake platform rear roller (6), respectively, the brake platform front roller (5) and the brake platform rear roller (6) are connected by a chain (2), the brake platform rear roller (6) is driven by a drive motor (8) to drive the brake platform front roller (5) to rotate synchronously, the encoder (14) is fixed on the code disc support swing arm (12), the code disc swing arm support shaft (16) and the code disc mounting bracket (7) bolt connection, fixed to the third roller swing support arm (3) through the code disk mounting bracket (7); two roller meter wheels (1) respectively measure the speed of the third roller contacted by the left and right wheels of the vehicle; a compression speed measuring wheel spring (9) fixed to the code disk support swing arm (12) is used to make the roller meter wheel (1) closely fit the third roller (4) during the measurement process; the measured speed is converted into an NPN incremental pulse signal through the encoder (14) on the meter wheel (1), and input into the USB3200N analog signal acquisition card (24) through the frequency signal transmitter, and finally uploaded to the computer; The two roller meter wheels (1) are connected in the same way, and a 24V switching power supply is used to ensure the normal operation of the encoder (14). The signal output terminal (20) of the encoder terminal (15) is connected to the signal receiving terminal (21) of the frequency signal transmitter, and another frequency signal transmitter signal receiving terminal (23) is additionally connected to a 2K resistor (28) in series with the positive electrode (27) of the power supply, and another frequency signal transmitter signal receiving terminal (23) of the frequency signal transmitter (22) is connected to the negative electrode (19) of the power supply; The frequency signal transmitter (22) is also powered by a 24V switching power supply, the positive electrode (29) of the output terminal is connected to the analog signal input terminal AI031 of the USB3200N analog signal acquisition card (24), and the negative electrode (30) of the output terminal is connected to the analog signal input terminal AGND32; The switch II (26) controlled by the brake pedal signal is connected in series with a resistor of 2K, and the two are connected in parallel with an 80K resistor, and a 5V switching power supply is supplied, and the positive electrode of the whole is connected to the digital circuit input terminal PFI135 of the USB3200N analog signal acquisition card (24), and the negative electrode is connected to the digital circuit input terminal DGND36 of the USB3200N analog signal acquisition card (24); The switch Ⅰ (25) for driving the motor stop signal control is connected in series with a resistor 2K, and the two are connected in parallel with an 80K resistor, and a 5V switching power supply is supplied. The positive electrode of the whole is connected to the digital circuit input terminal PFI034 of the USB3200N analog signal acquisition card (24), and the negative electrode is connected to the digital circuit input terminal DGND33 of the USB3200N analog signal acquisition card (24).

2. The real-time slip rate detector of the roller reaction type automobile brake test bench according to claim 1 is characterized in that: The program is programmed using libview on a computer. When the program starts running, the data acquisition card does not start collecting data. A conditional trigger is set in the program. When the brake pedal is pressed, data collection officially starts. During the data collection process, a real-time slip rate curve is displayed on the computer. The signal for the end of data collection is sent at the instant when the brake roller drive motor (8) stops working. When the program ends, the slip rate measured during the process is generated into a document.

3. The real-time slip rate detector of the roller reaction type automobile brake test bench according to claim 1 or 2, characterized in that: The code disc mounting bracket (7) is mounted on the T-slot nut guide rail (11) of the code disc bracket coupling claw (17) by means of bolts (10), and is slid and fixed laterally along the T-slot nut guide rail 11 by means of loosening and tightening the bolts (10), and the code disc bracket coupling claw (17) is then fixed to the third roller swing support arm (3) by means of a top screw (18).

4. The real-time slip rate detector of the roller reaction type automobile brake test bench according to claim 1 is characterized in that: The USB3200N analog signal acquisition card (24) is used to send a signal indicating the end of data acquisition at the instant when the brake roller drive motor (8) stops working. The equipment for data acquisition and control of acquisition stop is the same USB3200N analog signal acquisition card, and the two are performed in one program to ensure the accuracy of the data.

5. The real-time slip rate detector of the roller reaction type automobile brake test bench according to claim 1 is characterized in that: The roller meter wheel (1) is closely connected to the third roller (4) through a code disc mounting bracket (7) and a connecting claw of a third roller swing support arm, and the roller meter wheel (1) is moved laterally, so that the speed of the third roller (4) can be measured accurately and the structure is flexible.

6. The real-time slip rate detector of the roller reaction type automobile brake test bench according to claim 1 is characterized in that: The pulse of the roller meter wheel (1) is 1000P, and the circumference of the wheel is 200mm.

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