CN201322688Y

CN201322688Y - Brake testing machine

Info

Publication number: CN201322688Y
Application number: CNU2008201137054U
Authority: CN
Inventors: 粟定华; 赖小梅
Original assignee: HAOHUA SOUTH CHINA (GUILIN) RUBBER CO Ltd
Current assignee: HAOHUA SOUTH CHINA (GUILIN) RUBBER CO Ltd
Priority date: 2008-12-24
Filing date: 2008-12-24
Publication date: 2009-10-07
Anticipated expiration: 2018-12-24

Abstract

The utility model discloses a brake testing machine which comprises a fly wheel and a motor connected with the fly wheel and controlling the speed of the fly wheel, a tire is pressed on the fly wheel and a brake device with a friction material is mounted between the tire and a tire fixed axle. The brake testing machine is characterized in that the machine further comprises a fly wheel speed sensor, a brake moment sensor and a microprocessor. The fly wheel speed sensor and the brake moment sensor are connected to the input end of the microprocessor through signal wires; the internal memory of the microprocessor predicates the accumulated reduced energy of the fly wheel and calculates corresponding program for fly wheel testing speed; the obtained fly wheel testing speed is worked as the output signal of the microprocessor; and the output end of the microprocessor is connected with the control terminal of an electric motor. The brake testing machine can simulate the brake state of a practical brake device or a friction material more real and accurate.

Description

Brake testing machine

Technical field

The utility model relates to a kind of brake testing machine.

Background technology

At present, the domestic electrical analogue method that performance test adopted for brake gear or friction material, this method flywheel need not counterweights, flywheel and powerful motor direct connection or link by kinematic train.This motor can stepless time adjustment, and when tire presses flywheel, when carrying out skidding, the rotating speed perseverance of Electric Machine Control flywheel is decelerated to zero, with the velocity variations situation by control flywheel brake speed simulation actual brake process.Yet in the existing wheels-locked testing process, because flywheel deceleration and brake pressure are constant, and brake torque depends on the performance of brake material, therefore, when flywheel speed reduced to zero, the energy that absorbs of might braking did not reach or surpasses the brake energy that requires.In addition, in the actual vehicle brake process, even brake pressure is invariable, the variation of actual speed is not to be that a perseverance is decelerated to zero process yet, but an irregular velocity variations process, but speed will inevitably absorb certain brake energy when reducing to zero.Therefore, can not simulate the actual brake process fully by existing brake testing method, when carrying out the performance test of brake gear or friction material by existing method, the test findings of its gained and actual vehicle brake result are discrepant.

The utility model content

Technical problem to be solved in the utility model provides a kind of brake testing machine, and it can simulate the braking state of actual brake device or friction material more truly, exactly.

For addressing the above problem, the brake testing machine that the utility model is designed comprises flywheel and links to each other with flywheel and control the motor of flywheel speed that tire is pressed on the flywheel, and the brake gear that has friction material is installed between tire and the tire stationary shaft.Described flywheel speed sensor, brake torque sensor and the microprocessor of also comprising, the flywheel speed sensor links to each other with the input end of microprocessor by signal wire with the brake torque sensor, this microprocessor internal memory contains the energy of calculating that the flywheel accumulation reduces, calculate the program of corresponding with it flywheel measuring and calculating speed again, calculate the output signal of speed as microprocessor with the flywheel that obtains, the output terminal of microprocessor links to each other with the control end of motor.

In the such scheme, described microprocessor is for storing

V_{i} = V_{0} \times \sqrt{1 - \frac{Σ \frac{Mi}{r} \times V_{i} Δt}{E}}

Microprocessor, wherein E is the Brake Energy value that requires, r is the flywheel radius, V ₀Be initial flywheel speed, V _i' flywheel speed that measures in real time for the flywheel speed sensor, M _iBe the brake torque that the brake torque sensor measures in real time, Δ t is the sampling interval time.

In the such scheme, described motor requires can stepless time adjustment, corresponding given better performances, therefore motor described in the utility model servomotor preferably.

In the such scheme, the sampling interval time that described flywheel speed sensor and brake torque sensor detect in real time was less than 0.1 second.Optimum sampling interval time is 0.01 second.

The utility model adopts energy control method to carry out wheels-locked testing, compares with permanent rate of deceleration method, more near the actual conditions of vehicle brake.Simulate in the control using a computer, as long as interval time is enough short, the following feature of motor is good, and the effect of this test method can be quite desirable.It had both demonstrated the electric analogy testing machine and had adjusted flexible characteristic, had also taken into account inertia test machine " inertia braking " characteristics.When setting brake speed and brake energy, this method can just reach predetermined value by accumulated energy when brake speed is reduced to zero-speed, and makes the rate of deceleration and brake torque proportional, well simulating vehicle inertia braking process.This shows that this electric analogy testing method conforms to kinetic theory, can satisfy testing requirements fully.

Description of drawings

Fig. 1 is the control block diagram of a kind of brake testing machine of the utility model.

Embodiment

Fig. 1 is the control block diagram of a kind of brake testing machine of the utility model, includes the brake gear, flywheel, motor, flywheel speed sensor, brake torque sensor and the microprocessor that have friction material.The utility model motor, flywheel, tire and to have the mounting means of brake gear of friction material identical with existing brake testing machine, promptly tire is pressed on the flywheel of rotation, and the brake gear that has friction material is installed between tire and the tire stationary shaft.Motor and flywheel are direct-connected or link by kinematic train, and the speed of Motor Control flywheel reduces to zero, simulates the velocity variations situation of actual brake process with this.Different is, the flywheel speed sensor links to each other with the input end of microprocessor by signal wire with the brake torque sensor, and the output terminal of microprocessor links to each other with the control end of motor.The motor of the utility model brake testing machine requires the energy stepless time adjustment and responds given better performances, so the selected motor that has of the utility model most preferred embodiment is a servomotor.

It is the flywheel of r that the brake testing machine of the utility model most preferred embodiment is selected radius for use.At the beginning of the test, be flywheel starting velocity V with Brake Energy value E and the initial brake speed that requires ₀The parameter input microprocessor that these two users are given, and the operation program by the microprocessor stored

m = \frac{2 E}{{V_{0}}^{2}}

①

Be stored in the microprocessor after calculating the quality that this tire mounting vehicle works as.

Start brake testing machine then, microprocessor sends instruction to motor, and the driven by motor flywheel turns to flywheel beginning speed V ₀, the initial kinetic energy of flywheel promptly equals the Brake Energy value E of requirement at this moment.

Reach the flywheel beginning speed V of setting when the speed of flywheel ₀The time, the brake gear that has friction material is started working, and brake testing machine just formally enters the wheels-locked testing process.Then, the flywheel speed sensor flywheel speed V that will measure in real time _i', the brake torque that the brake torque sensor will measure in real time is M _iSend into microprocessor, then can be by the operation program of microprocessor stored

E_{i} = Σ \frac{Mi}{r} \times {V_{i}}^{,} dt

②

Calculate the energy that the flywheel accumulation reduces

According to theorem of kinetic energy, as the starting velocity V of flywheel ₀Be reduced to a certain speed V _iThe time,

E - Ei = m \times \frac{{V_{i}}^{2}}{2}

③

So composite type 1., 2. and 3., the flywheel measuring and calculating speed that can draw a certain moment flywheel correspondence should be

V_{i} = V_{0} \times \sqrt{1 - \frac{Σ \frac{Mi}{r} \times {V_{i}}^{,} dt}{E}}

④

Above-mentioned formula operation program 4. is stored in the microprocessor, this operation program can be by the flywheel speed and the brake torque of flywheel speed sensor and brake torque sensor The real time measure, calculate the energy that the flywheel accumulation reduces, and then calculate corresponding with it flywheel measuring and calculating speed.The flywheel measuring and calculating speed that obtains is as the output signal of microprocessor, the control end that the output terminal of this output signal by microprocessor is delivered to motor is used for the closed-loop control motor, adjusts flywheel speed, the retarded velocity of flywheel is directly proportional with brake torque, and the flywheel speed energy that accumulative total reduces when reducing to zero equal the Brake Energy value of requirement.

Certainly in wheels-locked testing process of the present utility model, the real-time sampling of flywheel speed sensor and brake torque sensor is short more interval time, more near the actual brake state.Yet in fact, the sampling time of flywheel speed sensor and brake torque sensor can not accomplish infinitely small, therefore the utility model most preferred embodiment is in carrying out above-mentioned simulation control procedure, double sampling Δ interval time t with sensor replaces dt, i.e. the program of the flywheel of microprocessor stored measuring and calculating speed is

V_{i} = V_{0} \times \sqrt{1 - \frac{Σ \frac{Mi}{r} \times {V_{i}}^{,} Δt}{E}}

This shows that as long as the sampling interval time is enough short, the following feature of motor is good, the effect of this test method still can be quite desirable.The sampling interval time that the utility model flywheel speed sensor and brake torque sensor detect in real time is preferably less than 0.1 second.As the utility model most preferred embodiment, the real-time sampling of described flywheel speed sensor and brake torque sensor is 0.01 second interval time.

Brake testing machine of the present utility model not only can carry out the detection of doughnut, and the detection of suitable and aero tyre tire or other friction materials.

Claims

1, brake testing machine, comprise flywheel and link to each other with flywheel, and the motor of control flywheel speed, tire is pressed on the flywheel, the brake gear that has friction material is installed between tire and the tire stationary shaft, it is characterized in that: the described flywheel speed sensor that also comprises, brake torque sensor and microprocessor, the flywheel speed sensor links to each other with the input end of microprocessor by signal wire with the brake torque sensor, this microprocessor internal memory contains the energy of calculating that the flywheel accumulation reduces, calculate the program of corresponding with it flywheel measuring and calculating speed again, the flywheel measuring and calculating speed that obtains is as the output signal of microprocessor, and the output terminal of microprocessor links to each other with the control end of motor.

2, brake testing machine according to claim 1 is characterized in that: described microprocessor is for storing

V_{i} = V_{0} \times \sqrt{1 - \frac{Σ \frac{Mi}{r} \times {V_{i}}^{'} Δt}{E}}

Microprocessor, wherein E is the Brake Energy value that requires, r is the flywheel radius, V ₀Be initial flywheel speed, V _i' measure flywheel speed in real time for the flywheel speed sensor, M _iBe the brake torque that the brake torque sensor measures in real time, Δ t is the sampling interval time of flywheel speed sensor and brake torque sensor.

3, brake testing machine according to claim 1 and 2 is characterized in that: described motor is a servomotor.

4, brake testing machine according to claim 1 and 2 is characterized in that: the sampling interval time of described flywheel speed sensor and brake torque sensor The real time measure was less than 0.1 second.

5, brake testing machine according to claim 4 is characterized in that: the sampling interval time of described flywheel speed sensor and brake torque sensor The real time measure is 0.01 second.