CN102774365A - Intelligent handbrake device and control method - Google Patents

Abstract

The invention discloses an intelligent handbrake device, which comprises a box body and a tensioning mechanism arranged in the box body. The rear end of the tensioning mechanism is connected with a vehicle brake cable. The front end of the tensioning mechanism is driven by a motor to tension and release the vehicle brake cable. The motor is controlled by an electric control unit. A limiting switch is arranged at the rear end of the tensioning mechanism, and is connected with the electric control unit. The electric control unit controls the rotation of the motor to implement or release parking according to an acquired motor rotating speed signal, a vehicle inclination angle signal, a brake cable displacement signal, a shoe temperature signal of brake calipers and a signal of the limiting switch. The intelligent handbrake device can be used for intelligently implementing/releasing the parking according to the intention of a driver in a full-intelligent mode.

Description

An intelligent handbrake device and control method

technical field

The invention relates to an intelligent handbrake device, in particular to an automobile intelligent handbrake device.

Background technique

The automobile brake system is mainly divided into a service brake system and a parking brake system. The service brake refers to the system used to implement the vehicle brake during the driving process of the vehicle. The parking brake is mainly used for the long-term stable parking system of the vehicle after the vehicle stops, also known as the hand brake.

At present, the handbrake of most models adopts the manual pull of the handbrake lever to implement the parking brake. During the process of pulling the handbrake, the driver often implements the parking brake force of the vehicle on different slopes according to experience and hand feeling, or directly applies the handbrake. The pull rod is pulled to the maximum stroke, so there is artificial uncertainty in the size of the parking brake. The pulling force applied by the driver directly affects the safety of parking and the overuse of components, thereby affecting the fatigue life of the components.

In the process of starting on a slope, the cooperation of the handbrake is also required to make the vehicle run normally, and the process is cumbersome, and the situation of slipping down the slope or even stalling due to erratic operation often causes potential safety hazards.

Contents of the invention

The technical problem to be solved by the present invention is to provide an intelligent hand brake device, which can automatically calculate the parking brake force required by the vehicle according to the slope angle of the road surface and the driving angle of the vehicle.

In order to solve the above-mentioned technical problems, the present invention adopts the following technical solutions: an intelligent handbrake device, including a box body and a tensioning mechanism arranged in the box body, the rear end of the tensioning mechanism is connected to a vehicle brake cable, which is characterized in that: The front end of the tensioning mechanism is driven by a motor to tighten and loosen the vehicle brake cable. The motor is controlled by an electronic control unit. A limit switch is arranged at the rear end of the tensioning mechanism. The electronic control unit controls the rotation of the motor according to the collected motor speed signal, vehicle inclination signal, brake cable displacement signal, brake caliper shoe temperature signal and limit switch signal to implement or release parking.

Preferably, the tensioning mechanism includes a gear transmission mechanism and a lead screw nut mechanism, the output shaft of the motor is connected to the gear transmission mechanism, the output gear of the gear transmission mechanism is fixed to the lead screw in the lead screw nut mechanism, and the screw in the lead screw nut mechanism The lever nut is connected to the vehicle brake cable.

As a preference, the gear transmission mechanism includes a motor gear mounted on the output shaft of the motor and a double gear, the double gear is arranged on a double gear shaft, the double gear is composed of a large gear and a small gear, the large gear and the The motor gear meshes, and the pinion gear meshes with the lead screw gear.

Preferably, the screw nut mechanism includes a lead screw and a lead screw nut matched with the lead screw, the lead screw gear is installed on the lead screw, the lead screw nut is arranged in a nut guide sleeve, and the bottom of the nut guide sleeve There is a spring, the screw nut is inserted into the nut guide sleeve and pressed against the spring, the guide block at the top of the screw nut is embedded in the guide groove at the top of the nut guide sleeve, the screw nut is fastened with a cable fixing seat, and the cable is fixed A brake cable hanging slot is provided at the end of the seat to connect the vehicle brake cable.

As a preference, the front end of the screw rod passes through the front end cover of the box, and the front end cover is provided with an end face bearing to support the lead screw, and a lock nut is threadedly connected to the front end of the screw rod for fastening, and the inner end face of the lock nut is pressed against the end face bearing On the outer end face, during the rotation of the screw rod, the lock nut compresses the bearing on the end face and rotates with the screw rod.

As a preference, the double gear shaft passes through the front end cover of the box body, and a hexagonal sink for matching with a hexagonal wrench is processed on the end surface of the double gear shaft.

Preferably, the electronic control unit is a single-chip microcomputer, and the single-chip microcomputer is connected with a motor speed sensor for collecting motor speed signals, a vehicle inclination sensor for collecting vehicle inclination signals, a temperature sensor for collecting brake caliper shoe temperature signals, and a vehicle brake sensor for collecting vehicle braking signals. Displacement sensor connection for guy wire displacement.

Preferably, the displacement sensor is hooked to the bottom of the screw nut, and the displacement sensor moves linearly with the screw nut synchronously and monitors the displacement signal.

The present invention also provides a control method for the above-mentioned intelligent handbrake device: it is characterized in that:

The electronic control unit controls the implementation of parking including the following steps: first, the electronic control unit calculates the required parking force according to the vehicle inclination angle signal and controls the motor to rotate forward; secondly, the electronic control unit performs control according to the motor speed signal. The electronic control unit controls the motor to stop. If the motor rotates forward, the electronic control unit adjusts the required parking force and controls the rotation of the motor according to the brake cable displacement signal and the shoe temperature signal of the brake caliper. Finally, if the required parking force is reached The electric control unit controls the motor to stop rotating, and the braking process ends. If the required parking force cannot be reached, the parking brake will continue to be applied;

The electronic control unit control to release the parking includes the following steps: first, the electronic control unit controls the motor to reverse, and secondly, the electronic control unit controls according to the motor speed signal. If the motor is rotating forward, the electronic control unit controls the motor to stop. Turn, the electronic control unit calculates the required parking force according to the displacement signal of the brake cable and controls the rotation of the motor. Finally, if the limit switch is closed, the electronic control unit controls the motor to stop rotating. If the limit switch is not closed, it needs to judge whether the required If the unlocking threshold is reached, the motor will continue to reverse for the set number of turns, and then the motor will stop rotating, and the braking process will end.

In the present invention, the tightening mechanism is driven by a motor to tighten the brake cable of the vehicle. The electronic control unit of the motor is based on the collected motor speed signal, vehicle inclination angle signal, parking brake force signal, limit switch signal and shoe temperature of the brake caliper. The signal controls the rotation of the motor, and the parking can be implemented or released through the positive and negative rotation of the motor. Therefore, it can automatically calculate the parking brake force required by the vehicle according to the slope angle of the road surface and the driving angle of the vehicle, and can also target the brake shoe. Temperature compensation is made for temperature changes, and then the appropriate parking brake is implemented, realizing the intelligent implementation/release of parking according to the driver's intention in the full intelligent mode.

Description of drawings

The present invention will be further described below in conjunction with accompanying drawing and specific embodiment:

Fig. 1 is the exploded diagram of this patent structure assembly;

Fig. 2 is the explosion diagram of the gear-screw drive of the patent;

Fig. 3 is the exploded view of the front end cover assembly with screw rod of this patent;

Figure 4 is an exploded view of the tensioning mechanism of the patent;

Fig. 5 is the front view of manual unlocking of this patent;

Figure 6 is a structural block diagram of the electric parking brake device, in which the assembly of the device is inside the solid line frame, and the parts connected to it are outside;

Fig. 7 is a circuit principle block diagram of the electric parking brake device;

8A is a schematic diagram of the motor forward and reverse control part of the motor drive circuit of the control circuit X;

8B is a schematic diagram of the motor loop current detection part and the motor freewheeling control circuit part of the motor drive circuit of the control circuit X;

8C is a schematic diagram of the detection circuit of the inclination sensor of the control circuit X;

FIG. 8D is a schematic diagram of a pull Hall sensor detection circuit of the control circuit X;

8E is a schematic diagram of the temperature detection circuit detection circuit of the control circuit X;

Fig. 9 is a logical block diagram of the parking brake;

Fig. 10 is a logical block diagram of releasing the parking brake.

Detailed ways

First, the mechanical structure of the intelligent handbrake device of the present invention will be described in detail with reference to FIGS. 1 to 6,

As shown in Figure 1, this kind of intelligent handbrake device includes: 1 tensioning mechanism, 2 upper end cover, 3 electronic control unit, 4 motor, 5 screw gear, 6 double gear, 7 front end cover, 8 sliding bearing, 9 bearing , 10 box, 11 screw, 12 limit switch, 13 rear end cover. The device is an electromechanical coupling product with compact structure, stable performance and comprehensive functions, which can effectively simplify the driver's operation and improve the superiority of the vehicle.

Specifically, the motor 4 is fastened to the box body 10 through bolts; the duplex gear 6 is installed in the gearbox of the box body 10 through the sliding bearing 8, and meshed with the lead screw gear 5; the lead screw gear 5 is installed in the box body through the bearing 9 10 inside the gear box and meshes with the double gear 6; the screw 11 and the screw gear 5 are fixed by keys; the front cover 7 is fastened to the box 10 by bolts, and the end face of the connection is provided with an end face sealing ring; the electronic control unit 3 passes Bolts are tightly connected to the upper end cover 2, and the upper end cover 2 and the box body 10 are fastened by bolts, and an end face sealing ring is provided on the connecting end face; the tensioning mechanism 1 has a built-in screw nut 1c and a screw rod 11 to engage and drive a linear motion, The rear end hanging groove of tensioning mechanism 1 can be hung with a vehicle brake cable.

As shown in Figure 2, the motor gear 42 is connected to the output shaft 41 at the front end of the motor to transmit torque, and the motor speed sensor 43 is connected to the end of the motor output shaft 41; the motor gear 42 meshes with the large gear in the double gear 6 and drives the double gear The gear rotates; the double gear pinion meshes with the lead screw gear 5 and rotates with the lead screw gear; the inner diameter of the lead screw gear 5 is provided with a keyway, and the lead screw 11 is connected with the lead screw gear through the key 14 and rotates with the lead screw gear; pull The tightening mechanism 1 has a built-in screw nut 1c that engages with the screw 11 and slides in the guide groove in the box body 10 to make a linear displacement. The bolts are installed in the box body 10 and arranged at the end of the tensioning mechanism 1 .

As shown in Figure 3, the front end of the screw rod passes through the front end cover 74 and is connected with the end face bearing 73, the lock nut 72 is threaded and fastened with the front end of the screw rod 11, and its end face is pressed against the end face of the end face bearing 73, and the screw rod 11 During the rotation, the lock nut 72 presses the end face bearing 73 and rotates with the screw rod. The front end cover plate 71 is tightly connected with the front end cover 74 by bolts to seal the corresponding components and limit the linear movement of the screw rod 11.

As shown in Figure 4, the energy storage device 1b is installed in the nut guide sleeve 1a, and the energy storage device is a spring; the screw nut 1c is inserted into the nut guide sleeve 1a and contains the energy storage device 1b as a whole, and the top of the screw nut 1c is guided The block is embedded in the top guide groove of the nut guide sleeve 1a; the top plate of the cable fixing seat 1d is in close contact with the end surface of the nut guide sleeve 1a and fastened by bolts, and the brake cable hanging groove is set at the end of the cable fixing seat 1d; the displacement sensor 1e is hung on The bottom of the screw nut moves linearly with the screw nut synchronously and monitors the displacement signal. The screw nut 1c is driven by the screw 11 and moves linearly under the limit of the guide groove at the top of the nut guide sleeve 1a, presses the energy storage device 1b to generate displacement and pushes the nut guide sleeve 1a to make a linear motion, and the electronic control unit 3 calculates according to the displacement Braking tension; at the same time, the cable fixing seat 1d tightly connected with the nut guide sleeve 1a moves linearly in the same direction, and then drives the brake cable in the hanging groove to move as a parking brake.

The nut guide sleeve is rigidly connected with the cable fixing seat, and is in a tensioned state with the brake cable; the screw nut is driven by the screw rod to move axially, and compresses the compression spring, and because the displacement sensor is fixed on the screw nut, Therefore, at the same time, it moves axially with the screw nut, thereby generating displacement. That is to say, this displacement corresponds to the compression amount of the compression spring, and the spring pressure corresponds to the pulling force required by the parking brake (that is, the parking force).

The initial state of the limit switch 12 is connected to the top plate of the cable fixing seat 1d, and provides a reset signal for braking initialization during installation, disassembly and adjustment of this kind of smart handbrake device.

Parking brake:

As shown in Figure 1, the electronic control unit 3 controls the motor 4 to rotate forward, the double gear 6, the screw gear 5, and the screw 11 are driven by the motor gear to rotate forward at the same time, and then the tensioning mechanism 1 makes a forward linear motion, implementing Parking brake.

As shown in Figure 9, the electronic control unit controls the implementation of parking including the following steps;

Firstly, the electronic control unit calculates the required parking force according to the vehicle inclination signal and controls the motor to rotate forward. Secondly, the electronic control unit makes control according to the motor speed signal. If the motor reverses, the electronic control unit controls the motor to stop. The electronic control unit adjusts the required parking force and controls the rotation of the motor according to the displacement signal of the brake cable and the temperature signal of the shoe of the brake caliper. Finally, if the required parking force is reached, the electronic control unit controls the motor to stop rotating, and the brake After the start process is over, if the required parking force cannot be reached, continue to apply the parking brake;

To release the parking brake:

As shown in Figure 1, the electric control unit 3 controls the motor 4 to reverse, and the double gear 6, the screw gear 5, and the screw 11 are driven by the motor gear to rotate in the opposite direction at the same time, and then the tensioning mechanism 1 makes a reverse linear motion, and stops. The car brake is released.

As shown in Figure 10, the control of the ECU to release the parking includes the following steps: firstly, the ECU controls the motor to reverse, and secondly, the ECU makes control according to the motor speed signal. If the motor rotates forward, the ECU controls the motor stop, if the motor reverses, the electronic control unit calculates the required parking force according to the brake cable displacement signal and controls the motor to rotate, and finally, if the limit switch is closed, the electronic control unit controls the motor to stop rotating, if the limit switch is not closed It is necessary to judge whether the required unlocking threshold is reached. If the unlocking threshold is reached, the motor will continue to reverse the set number of turns, and then the motor will stop rotating, and the braking process will end.

After detecting whether the logic threshold a is reached, continuing to reverse N circles is the automatic gap adjustment function. This function is provided by mechanical components on traditional brakes, but it is realized by the control unit in this mechanism, which is more reliable and accurate.

Manual release of parking:

As shown in Figure 5, the rotating shaft of the dual gear 6 communicates with the front end cover 7, and the front end of the rotating shaft is processed with a hexagonal sinking platform 16. Rotate to, and then drive screw gear 5, screw mandrel 11 counter-rotate, reach and remove parking effect.

Refer to Fig. 6 and Fig. 7 to explain the circuit principle block diagram and working principle: please refer to Fig. 7 for the circuit principle block diagram. Composition of electrical components in control circuit component X, control circuit component X does not include motor X, stroke sensor X, limit switch, automatic mode switch, manual parking switch and manual release switch, but these electrical components are included in the device; The outside frame indicates the connection between the outside world and the circuit in the device, including ignition switch, brake switch, etc.

The principle of several important functional modules in the control circuit X, including the motor drive circuit, the detection circuit of the inclination sensor, the detection circuit of the tension sensor and the detection circuit of the temperature sensor, the principle is explained as follows:

The entire motor drive circuit is divided into the following important parts: the motor forward and reverse control part, the motor loop current detection part, and the motor freewheeling control circuit part. Refer to Figure 8A for the forward and reverse control part of the motor, and Figure 8B for the motor loop current detection part and the motor freewheeling control circuit.

The forward and reverse control part of the motor: through the output terminal FWD and REV of the single-chip microcomputer to drive the conduction and cut-off of the transistors Q1 and Q2, to control whether the inductance coil between pins 2 and 3 and between pins 4 and 5 in the relay is energized, so as to Control the pull-in and disconnection of the contact 7 or 8 of the relay, and the common end of the relay is respectively connected to the two-stage Motor++ and Motor-- of the motor, so as to coordinate and control the forward and reverse rotation of the motor. Motor loop current detection part: This part detects the motor loop current through the chip BTS443P. According to the characteristics of the motor, we use two BTS443P in parallel to increase the range. The single-chip microcomputer outputs the Motor_Control signal to drive the chip BTS443P to work, so that the motor can work normally. At this time, the chip BTS443P can sense the motor loop current, and output the corresponding proportional feedback current through the chip pin 4. The feedback current flows through the resistor R10, and R10 generates Voltage drop, this voltage value is input to the MCU pin MotorCurrent_Detection_AD for detection, that is, the motor loop current value is detected. Motor freewheeling control circuit part: when the control motor stops, the MCU Motor_Control signal controls the BTS443P to stop. At this time, the current flows through the freewheeling diode D9 or D10. After the motor stops, the MCU stops outputting the forward and reverse control signal FWD or REV.

Motor speed sensor function:

a) Judging the positive and negative rotation of the motor, and actually implementing parking/releasing the brake correspondingly;

b) In the function of automatic gap adjustment (see the logic block diagram of parking release), the motor reverses N turns and the motor sensor recognizes the number of turns signal.

Inclination sensor: This component is built into the circuit board and placed horizontally. It can monitor the direction of vehicle travel and the inclination angle of front and rear vehicles, and provide angle signals for the control unit. The vehicle travel angle can be provided by an inclination sensor. is a negative inclination.

Parking brake force signal: the displacement sensor at the bottom of the screw nut. The controller calculates the braking force from this displacement.

Temperature sensor: Arranged inside the brake caliper, connected to the control unit through wires. The sensor monitors the temperature change of the caliper shoe and provides a temperature signal for the control unit. Based on this, the control unit calculates the thermal decay of the shoe due to temperature change and the change of the shoe clearance caused by the thermal expansion of the shoe. And accordingly implement feedback control to the actuator.

Please refer to Figure 8C for the detection circuit of the inclination sensor. The inclination sensor is a mature product SCA60C. The sensor is externally connected to a 5V drive power supply, and pin 7 is an analog voltage signal output pin. Connect VOUT to the analog conversion pin of the MCU to sample the voltage value.

Please refer to Figure 8D for the detection circuit of the tension sensor. The linear Hall sensor is SS495A. The output of the linear Hall sensor of the SS490 series is a ratiometric voltage output related to the supply voltage. When working normally, its output signal pin 3 is connected to the analog conversion pin of the MCU, and the voltage value sampling can be performed.

Please refer to Figure 8E for the temperature sensor detection circuit. The temperature sensor is DS1820. The sensor is externally connected to a 5V drive power supply, and pin 2 is a digital signal output pin. When working normally, connect the DQ pin to the MCU pin to read data.

In summary, the present invention has the following advantages:

1. It can automatically calculate the parking brake force required by the vehicle according to the slope angle of the vehicle driving road and the driving angle of the vehicle.

2. It has the function of automatic gap adjustment. In the process of releasing the parking brake, the parking tension signal is collected, and the fixed return stroke is set according to the nominal tension, so as to achieve clearance adjustment. After a vehicle using a traditional handbrake device is used for a long time, the brake cable is often deformed, and its length gradually increases, thereby affecting the parking brake force and the parking operation response. This patent collects the parking pull force signal during the process of releasing the parking brake, and sets a fixed return stroke according to the nominal pull force, so as to achieve clearance adjustment.

3. With temperature compensation function. It can monitor the temperature change of each component in the braking process in real time, and calculate the deformation of each component, and make temperature compensation according to the deformation, and then implement appropriate parking brake. The vehicle often implements the service brake before the parking brake. The service brake force and braking time are different under different road conditions, and the heat generated by the friction of the brake shoe and the brake disc is also very different. The thermal deformation of the moving shoe is also different, so the parking force needs to be implemented according to the different thermal deformation under different working conditions. The patent can monitor the temperature change of each component in the braking process in real time, calculate the deformation of each component, make temperature compensation according to the deformation, and then implement appropriate parking brake. This function is especially effective in vehicle emergency braking

4. With the function of initial reset, the limit switch implements brake initialization during the installation, disassembly and adjustment of this kind of intelligent handbrake device.

Claims (9)

1. An intelligent handbrake device, comprising a box body (10) and a tensioning mechanism (1) arranged in the box body, the rear end of the tensioning mechanism is connected to the vehicle brake cable, and it is characterized in that: the front end of the tensioning mechanism The tensioning and loosening of the vehicle brake cable is driven by the motor (4), the motor is controlled by the electronic control unit (3), and a limit switch (12) is arranged at the rear end of the tensioning mechanism. The electronic control unit controls the rotation of the motor to implement or release parking according to the collected motor speed signal, vehicle inclination signal, brake cable displacement signal, brake caliper shoe temperature signal and limit switch signal. 2. An intelligent handbrake device according to claim 1, characterized in that: the tensioning mechanism includes a gear transmission mechanism and a screw nut mechanism, the output shaft of the motor is connected to the gear transmission mechanism, and the output gear of the gear transmission mechanism is connected to the wire The leading screw in the screw nut mechanism is fixed, and the leading screw nut in the leading screw nut mechanism is connected with the vehicle brake pull wire. 3. An intelligent handbrake device according to claim 2, characterized in that: the gear transmission mechanism includes a motor gear (42) mounted on the motor output shaft (41) and a double gear (6). The gear is arranged on a duplex gear shaft, and the duplex gear is made up of a large gear and a small gear, the large gear meshes with the motor gear, and the pinion meshes with the threaded screw gear (5). 4. An intelligent handbrake device according to claim 3, characterized in that: the screw nut mechanism includes a screw (11) and a screw nut (1c) matched with the screw, and the screw gear is installed On the lead screw, the lead screw nut is arranged in a nut guide sleeve (1a). A spring is provided at the bottom of the nut guide sleeve. Embedded in the guide groove at the top of the nut guide sleeve, the lead screw nut is fastened to a cable fixing seat (1d), and the end of the cable fixing seat is provided with a brake cable hanging groove to connect the vehicle brake cable. 5. An intelligent handbrake device according to claim 4, characterized in that: the front end of the screw rod passes through the front end cover (74) of the box, and an end face bearing (73) is provided in the front end cover to support the screw, and a The lock nut (72) is threadedly connected with the front end of the screw rod, and the inner end face of the lock nut presses the outer end face of the end face bearing. During the rotation of the screw rod, the lock nut compresses the end face bearing and rotates with the screw rod. 6. An intelligent handbrake device according to claim 5, characterized in that: the double gear shaft passes through the front end cover of the box body, and the end surface of the double gear shaft is processed with a hexagonal sinker matched with a hexagonal wrench (15). Taiwan (16). 7. An intelligent handbrake device according to claim 6, characterized in that: the electronic control unit (3) is a single-chip microcomputer, and the single-chip microcomputer is connected with the motor speed sensor (43) for collecting the motor speed signal and for collecting the vehicle inclination angle. The vehicle inclination sensor for the signal, the temperature sensor for collecting the temperature signal of the brake caliper shoe, and the displacement sensor (1e) for collecting the displacement of the vehicle brake cable are connected. 8. An intelligent handbrake device according to claim 7, characterized in that: the displacement sensor (1e) is hooked to the bottom of the screw nut (1c), and the displacement sensor moves linearly synchronously with the screw nut and Monitor the displacement signal. 9. A control method for an intelligent handbrake device, characterized in that: The electronic control unit controls the implementation of parking including the following steps: first, the electronic control unit calculates the required parking force according to the vehicle inclination angle signal and controls the motor to rotate forward; secondly, the electronic control unit performs control according to the motor speed signal. The electronic control unit controls the motor to stop. If the motor rotates forward, the electronic control unit adjusts the required parking force and controls the rotation of the motor according to the brake cable displacement signal and the shoe temperature signal of the brake caliper. Finally, if the required parking force is reached The electric control unit controls the motor to stop rotating, and the braking process ends. If the required parking force cannot be reached, the parking brake will continue to be applied; The electronic control unit controls the release of parking including the following steps: first, the electronic control unit controls the motor to reverse, and secondly, the electronic control unit controls the motor according to the motor speed signal. If the motor rotates forward, the electronic control unit controls the motor to stop. Turn, the electronic control unit calculates the required parking force according to the displacement signal of the brake cable and controls the rotation of the motor. Finally, if the limit switch is closed, the electronic control unit controls the motor to stop rotating. If the limit switch is not closed, it needs to judge whether the required If the unlocking threshold is reached, the motor will continue to reverse for the set number of turns, and then the motor will stop rotating, and the braking process will end.

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