JPS61205540A - Wheel slip prevention device - Google Patents

Abstract

PURPOSE:To prevent the slip of wheels by detecting the slip generated at start and acceleration and allowing driving wheels to operate desired braking force. CONSTITUTION:If excessive torque is generated in front wheels 30a and 30b that are driving wheels when a car body starts and is accelerated, a large rotation difference is generated between the front wheels 30a, 30b and rear wheels 30c, 30d. In this case, an electronic control unit 45 detects a driving wheel slip by comparing and computing signals from wheel speed pulse generators 46a-46d. The electronic control unit 45 sends a control signal to a control valve 37 for pressurization and actuates the control valve 37. As a result, a piston 49 is operated through a cylinder 48 for pressurization and a brake pedal 32 is stepped in. Simultaneously with this, the unit 45 generates a signal that disconnects a liquid path between the master and wheel cylinder sides in a reduction device 42.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a wheel slip prevention device for automobiles, two-wheeled vehicles, etc., and particularly relates to a wheel slip prevention device that prevents wheels from slipping during starting, acceleration, etc. .

Conventional Technology When the drive wheels rotate at high speed during start-up and acceleration, and the difference in rotation between the drive wheels and the non-drive wheels becomes large, slippage occurs in the drive wheels. The anti-slip device that tries to prevent this slip is JP-A-Bl? It is disclosed in Japanese Patent No. 59-145652. FIG. 4 is a sectional view of a brake booster used in the anti-slip device disclosed in Japanese Unexamined Patent Publication No. 59-145652, and FIG. 5 is a schematic diagram of this anti-slip device.

First, FIG. 4 will be explained. Inside the brake booster 1, a chamber A and a chamber B are provided with a power piston 2 in between. Piping is provided between the A room and the B room via the main solenoid valve 3. The manifold negative pressure is guided to chamber A and also to chamber B via the solenoid valve 4. Atmospheric air is guided to B via the solenoid valve 5. Further, as shown in the figure, a differential pressure sensor 6 is provided between chamber A and chamber B.

The main solenoid valve 3 is of the normal oven type, and the solenoid valves 4 and 5 are of the normally closed type. Therefore, under normal conditions, it functions as an ordinary brake booster. On the other hand, if the main solenoid valve 3 is closed and the M11 valves 4 and 5 are turned on and off to change the pressure in chamber B under microcomputer control, the power piston 2 will respond to the pressure difference between chamber B and A. Transmits proportional force to the master cylinder. As a result,
Braking force is generated without any pedal effort.

Next, FIG. 5 will be explained. This anti-slip device is applied to front-wheel drive vehicles. In the figure, 7 is a brake pedal, 8 is a master cylinder, and 9 and 10 are drive wheels, a right front wheel and a left front wheel, respectively. Reference numerals 11 and 12 denote a right rear wheel and a left rear wheel, respectively, which are non-driving wheels. Each wheel 9.10.11.12 is provided with a disc-type brake actuator 13, 14, 15.16, respectively. Also, as shown in the figure, the master cylinder 8
A first -Jail valve 17 is disposed in an oil passage leading from the front right wheel brake operating section 13 to the right front wheel brake operating section 13 . Further, a second control valve 18 is disposed in an oil passage leading from the master cylinder 8 to the left front wheel brake actuation section 14 . and,
The oil passage leading from the master cylinder 8 to the right rear wheel brake actuator 15 and the left rear wheel brake actuator 16 includes a third
A control valve 19 is arranged in common. Furthermore, a shutoff valve 20 is arranged in the oil passage leading from the master cylinder 8 to the left rear wheel brake actuation part 16, and a shutoff valve 21 is arranged in the oil passage leading to the right rear wheel brake actuation part 15. .

Next, the operation of the anti-slip device shown in FIG. 5 will be explained. For example, when starting, if the rotational difference between the driving wheels 9, 10 and the non-driving wheels 11, 12 increases, the microcomputer detects this and activates the brake booster 1.
Apply a predetermined braking force to the At the same time, the shutoff valves 20 and 21 are closed to apply braking force only to the drive wheels 9 and 10 that are slipping, thereby suppressing slippage. In addition, since the braking force of the drive wheels 9.10 is controlled by the first and second control valves 17.18 which are independent of each other, even on road surfaces where only one of the drive wheels 9, 10 slips, the braking force can be controlled appropriately. This allows for a smooth start.

Problems to be Solved by the Invention In the anti-slip device disclosed in Japanese Patent Application Laid-Open No. 59-145652, the electromagnetic valve-controlled brake booster 1 configured to generate brake fluid pressure during no braking is The structure is complex and difficult to manufacture. In particular, the double capalub part and the main it! ! ! The passage connecting the valve 1 and the valve 3 must be made flexible without interfering with the return spring or slidable on the outer wall of the shell, but this is extremely difficult. Furthermore, in the above anti-slip device, two ffi magnetic valves 20 are used to close the fluid passages leading to the rear wheel brake actuating parts 15 and 16.
, 21 have been proposed, resulting in a total of five solenoid valves being required. Therefore, the entire device becomes large and the cost becomes high.

SUMMARY OF THE INVENTION Therefore, it is an object of the present invention to provide a wheel slip prevention device which is capable of achieving the above-mentioned operation and which is simple in structure and easy to manufacture.

Means for Solving the Problems The wheel slip prevention device according to the present invention includes a brake pedal, a pressurizing device, a master cylinder, a pressure reducing device, and an electronic control device. The pressurizing device is configured so that the driver can press the brake pedal even when the driver does not press the brake pedal. The master cylinder converts the operating force from the brake pedal into braking fluid pressure. The pressure reducing device is located between the brake of each wheel and the master cylinder, and can cut off or reduce the brake fluid pressure for each wheel. Further, the electronic control I device determines a desired braking force for each wheel from various information including at least information regarding the rotational speed of each wheel, and controls the pressurized bag @ and the decompression device to generate the desired braking force. control. At least regarding the driving wheels, the pressure reducing device is independently arranged for each wheel. In addition, when the electronic control device controls the pressurization IA position so as to press the brake pedal independently of the driver's driving operation, the pressure reduction device disposed in the fluid path leading to the non-driving wheels is controlled by the electronic control device. The liquid path can be shut off by command.

In a preferred embodiment of the present invention, the vehicle further includes a brake switch capable of detecting that the brake pedal is operated by a driving action by the driver. Information from this brake switch is supplied to an electronic control system.

Effect: For example, when starting, if excessive torque is generated in the drive wheels,
The drive wheels slip, creating a large rotational difference between them and the non-drive wheels. In such a case, the electronic control unit 1 detects drive wheel slip and calculates a desired braking force for the drive wheels. Then, in order to produce this desired braking force,
Controls pressurization and depressurization devices. The brake pedal is pressed in response to the operation of the pressurizing device, and hydraulic pressure is generated in the master cylinder. The reduced pressure @11 located in the fluid path between the master cylinder and the non-driving wheels is given a command from the electronic control device to shut off the fluid path. Therefore, the hydraulic pressure generated from the master cylinder is applied only to the drive wheels. Furthermore, at least regarding the drive wheels, a pressure reducing device is placed independently for each wheel, so even if only one of the two drive wheels slips, it is possible to prevent that slip. I can do it.

Embodiment [ FIG. 1 shows an outline of an embodiment of the present invention. This embodiment is applied to a front wheel drive vehicle. In the figure, 30a and 30b are a right front wheel and a left front wheel, respectively, and both are drive wheels. 30c and 30
d are the right rear wheel and the left rear wheel, which are non-driving wheels, respectively. Each wheel has a brake actuation section 318.31
b, 310.31d. As shown in the figure, a pressurizing device 70 is provided to apply pressurizing force to the brake pedal 32. This pressurizing device 70 includes a pressurizing hydraulic cylinder 48 connected to the brake pedal 32 so as to be able to operate the brake pedal 32, and a pressurizing control valve that can change the force acting on the pressurizing cylinder 48. Contains 37. The pushing force of the pressurizing hydraulic cylinder 48 is obtained by pressurizing the hydraulic oil in the reservoir tank 35 with the pump 36 and controlling the accumulated pressure in the accumulator with the pressurizing control valve 37. The pressurizing cylinder 48 has a piston 49, and this piston 4
9 is connected to the brake pedal 32. In this embodiment, the pressurization control valve 37 has three positions! 1J1ilI valve is used. The pressurization control valve 37 may be controlled by known pulse width modulation techniques, but is not limited thereto. In order to perform smoother control more reliably, a variable flow rate control valve may be used as the pressurization control well 37.

There are many known variable flow rate control valves such as servo valves and proportional solenoid valves. In addition, 3 positions are used in this example! Instead of the IIIl valve, two two-position control valves may be used.

The operating force from the brake pedal 32 is converted into hydraulic pressure by the existing booster and master cylinder 33.

Two liquid passages 38 and 39 come out from the master cylinder 33. As shown in the figure, a pressure reducing device 40a is disposed in the dark liquid path between the master cylinder 33 and the right front wheel brake actuation section 31a. Similarly, a pressure reducing device 40b is arranged in the fluid path between the master cylinder 33 and the left front wheel brake actuation section 30b. Pressure reducing devices 40a and 40b
Both have an anti-lock function. The brake operating portion 31c of the rear wheel 30 (!, 30d) is a non-driving wheel.

In the liquid path between 31d and the master cylinder 33, one pressure reducing device @42 is disposed in common. This pressure reducing device 42 has an anti-lock function like the pressure reducing devices 40a and 40b, and also has a function of blocking the fluid path between the master cylinder 33 and the rear wheel brake operating parts 31c and 31d. It should be noted here that, at least with respect to the drive wheels, the pressure reducing device is arranged independently for each wheel. Regarding the non-driving wheels, one pressure reducing device 42 may be commonly disposed as in this embodiment, but it goes without saying that a pressure reducing device may be provided independently for each wheel. Pressure reducing device 40a.

The structures of 40b and 42 will be explained using FIG.

Further, as shown in the figure, a P-pulp (a known pure mechanism i*[) 43, 44 that approximates the front-rear hydraulic pressure distribution by a polygonal line is disposed between the pressure reducing device 142 and the master cylinder 33. Pressurization control valve 37 and each pressure reducing device 40a
, 40b, 42 are sent from an electronic control unit or microcomputer 45. Then, send that signal. The information that should be used as a basis for judgment is the four wheel speed pulse generators 4 provided in relation to the front wheels 30a, 3Qb and the rear wheels 30c, 30d.
6a, 46b, 46c, 46d and a brake switch 47 provided in association with the brake pedal 32.

Next, a description will be given of how the wheel slip prevention device configured as described above operates to prevent wheel slip, for example, during start acceleration. The front wheel 30a is the driving wheel when the vehicle starts or accelerates,
When excessive torque is generated at 30b, the front wheels 30a, 3
0b slipped, and the rear wheel 30C, which is a non-drive wheel,
, 30d. In such a case, the electronic control device 45 controls the wheel speed pulse generator 4
Drive wheel slip is detected by comparing and calculating signals from 6a, 46b, and 460.46d. Then, the electronic control m device 45 uses the control signal for pressurization! 1J ti
ll valve 37, and the vJ control valve 37 is operated. In response to the operation of the control valve 37, liquid pressurized by the pump 36 is sent into the pressurizing cylinder 48. As a result, the piston 49 operates and pushes the brake pedal 32. At the same time, the electronic control device 145
2, sends a signal to cut off the fluid path between the master cylinder side and the wheel cylinder side. Therefore, the hydraulic pressure generated from the master cylinder 33 is applied to the front wheels 3 which are the driving wheels.
It acts only on the brake actuation parts 318.31b of 0a and 30b. Note that at this time, the pressure reducing devices 40a and 40b are each independently controlled by a control signal from the electronic control device 45, so that, for example, the two drive wheels 30
It is possible to start even in a situation where only one of wheels a and 30b slips. In this way, it is possible to always obtain directional stability and maximum acceleration of the vehicle even under slippery conditions such as muddy, icy, or snowy roads.

Next, an explanation will be given of the anti-lock function that prevents the wheels from locking when the brakes are applied. The driver presses the brake pedal 3
2, a signal from the brake switch 47 is sent to the electronic 84 Ill system W1145, and as a result, the electronic control unit 6F45 determines that the current situation is braking. And this electronic control device! 45 is a wheel speed pulse generator 46a, 45b, 45c,
When a situation where the brakes are about to lock is detected by calculating the signal from the brakes 45d, the pressure reducing devices 40a and 40b are used to lower the hydraulic pressure of the wheel brakes that are about to lock.
, 42 to send the necessary signals. At this time, the vacuum bags are connected to the right front wheel brake operating section 31a and the left front wheel brake operating section 31b, respectively! f40a and 40b are independently controlled. Therefore, front wheels 30a and 30b
The braking force for the left and right sides is controlled independently. On the other hand, since one pressure reducing device 42 is disposed in common for the rear wheels 30C and 30d, the rear wheels 30C and 30d
And 30d, the braking force of the left and right wheels will be controlled simultaneously.

In this way, the electronic control unit 45 optimally determines the brake fluid pressure for each wheel, so that each wheel slip rate is within the optimal range, resulting in a reduction in vehicle directional stability, vehicle steering performance, and braking distance. can be achieved.

The above explanation was given using a front-wheel drive vehicle as an example, but even in a rear-wheel drive vehicle, if one anti-lock pressure reducing device is added,
This is achieved by installing a total of four pressure reducing devices on each side of the front and rear wheels. In other words, to prevent drive wheel slippage, brake hydraulic pressure is prevented from being applied to the front wheels using an antilock pressure reducing device for the front wheels (non-drive wheels), and when antilock operation is performed, the antilock pressure reduction device for the front wheels (non-drive wheels) is used to prevent brake hydraulic pressure from being applied to the front wheels. This is achieved by controlling the locking pressure reducing device a.

2. ``Kuchimame J-'' FIG. 2 shows a principle diagram of the vacuum bag W140 shown in FIG. 1. Since the decompression devices 40 and 42 have substantially the same configuration, the decompression bag f will be described below to represent them.
f40 will be explained. The pressure reducing device 40 includes a pressure reducing hydraulic cylinder 50 and a pressure reducing control valve 52. The pressure reducing hydraulic cylinder 50 has a piston 53 that can change the braking force applied to the wheels. Furthermore, within the pressure reducing hydraulic cylinder 50, there are three chambers 54, 55, and 56. The chamber 54 is connected to the master cylinder side via the boat 57 31! Omitted. The chamber 55 communicates with the front wheel brake operating section via a boat 58. Further, the auxiliary power circuit 51 is connected to the boat 59 in the chamber 56.
We are in contact via.

The piston 53 has a ball valve 60 at its right end in the figure.
and a spring 6 disposed within the chamber 54.
1, it is always urged to move to the left.

When the pressure reducing control valve 52 is inactive, the piston 53 is located at the right end, as shown in FIG. and,
When the pressure reducing control valve 52 operates, the piston 53 begins to move to the left, and the communication between the chambers 54 and 55 is blocked by the ball valve 60.

Although the auxiliary power circuit 51 is common to the auxiliary power circuit connected to the pressurizing device as shown in FIG. 1, there is no problem in making it separate. Further, as shown in the figure, a pressure reducing control valve 52 is disposed within the auxiliary power circuit 51. This pressure reduction control valve 52 controls the hydraulic pressure acting on the piston 53 of the pressure reduction hydraulic cylinder 50. In this example,
A three-position control valve is used as the pressure reduction control valve 52.

Instead of this three-position control valve 52, it is possible to use two two-position control valves.

The state shown in FIG. 2 is the normal state. That is,
No current flows through the solenoid of the pressure reducing control valve 52. In that case, the hydraulic pressure provided by the pump 36 is introduced into the chamber 56, pushing the piston 53 to the rightmost position it can go to. Therefore, the chambers 54 and 55 are in communication with each other, and therefore, the master cylinder side and the front wheel brake operating section side are in communication with each other. Now, if the three-position control valve 52 operates and the pressure in the chamber 56 drops, the piston 53 will move to the left due to the hydraulic pressure from the master cylinder and the biasing force of the spring 61. Immediately after the piston 53 starts moving leftward, communication between the chambers 54 and 55 is interrupted. In this way, when the brake stone 53 moves left and right according to the operation of the three-position control valve 52 and the volume of the chamber 55 changes, the brake fluid pressure path communicating with the chamber 55 changes.
The hydraulic pressure of the pump changes. In this way, the anti-lock function is fulfilled.

FIG. 3 is a diagram showing a connecting portion between the brake pedal 32 and the pressurizing hydraulic cylinder 48 shown in FIG. 1.

In the figure, the brake pedal 32 rotates around a fulcrum 62. Further, the brake pedal 32 and the master cylinder are connected via a pin 63. Further, the four pistons of the cylinder 48 and the brake pedal 32 are connected via pins 63 and 64. Further, the cylinder 48 is rotatably attached to its attachment portion via a pin 65. When hydraulic pressure from the pump 36 is applied to the piston 49 of the cylinder 48, the piston 49 moves, and the bottle 64 moves circularly around the fulcrum 62 accordingly. As a result, the bin 63 moves forward. In other words, the brake pedal 32 is pushed in. In addition,
In FIG. 3, the cylinder 48 is installed above the brake pedal 32 so as not to interfere with the driver. However, it is not necessary to install the cylinder 48 in such a position, and the cylinder 48 may be installed in any position as long as the operation of the brake pedal 32 as described above can be achieved. Note that the brake switch 47 needs to be installed so that it does not respond to the force received from the pressurizing hydraulic cylinder, but only responds to the driver's brake operation force.

That is, the brake switch 47 is connected to the brake pedal 3 below the pin 63 connected to the master cylinder.
2 must be attached.

Note that although the embodiments described above were applied to four-wheeled vehicles, they can be similarly applied to two-wheeled vehicles.

Effects of the Invention As described above, according to the present invention, since it has an anti-lock function and a drive wheel slip prevention function, the maximum possible acceleration and deceleration can always be performed even on a road surface with a low coefficient of friction. In addition, its structure is simpler than that of the anti-slip device disclosed in Japanese Patent Application Laid-Open No. 59-145652,
Therefore, it is easy to manufacture. This will become clear if we assume that a drive wheel slip prevention function is to be added to the anti-lock system. That is, in such a case, in the anti-slip device disclosed in Japanese Patent Application Laid-Open No. 59-145652, the four valves and the booster must be significantly modified. On the other hand, according to the present invention, it is only necessary to add a pressurizing device to a so-called pure mechanical type booster that has been generally used in the past, and there are few changes.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an embodiment of the present invention. FIG. 2 is a principle diagram of the pressure reducing device 40 shown in FIG. 1. FIG. 3 is a diagram showing a connecting portion between the brake pedal 32 and the pressurizing hydraulic cylinder 48 shown in FIG. 1. FIG. 4 is a sectional view of a brake booster used in an anti-slip device disclosed in Japanese Patent Application Laid-Open No. 59-145652. FIG. 5 is a schematic diagram of an anti-slip device disclosed in Japanese Patent Application Laid-Open No. 59-145652. In the figure, 32 is a brake pedal, 33 is a master cylinder, 37 is a pressurization control valve, 408.4Qb, 42 is a pressure reducing device, 48 is a pressurization hydraulic cylinder, 50 is a pressure reduction hydraulic cylinder, 52 is a pressure reduction control valve, 70 indicates a pressurizing device.

Claims (3)

[Claims] (1) A brake pedal, a pressurizing device configured to apply pressurizing force to the brake pedal, a master cylinder that converts the operating force from the brake pedal into hydraulic pressure, a brake for each wheel, and a pressurizing device configured to apply pressure to the brake pedal. A pressure reducing device is located between the master cylinder and can cut off or reduce the braking fluid pressure for each wheel, and a desired braking force for each wheel is calculated from various information including at least information regarding the rotational speed of each wheel. an electronic control device that controls the pressure device and the pressure reduction device to generate a braking force; at least with respect to drive wheels, the pressure reduction device is arranged independently for each wheel; and the electronic control device When the pressurizing device is controlled to press the brake pedal independently of the driving operation by the driver, the depressurizing device disposed in the fluid path leading to the non-driving wheels is controlled by the command from the electronic control device. A wheel slip prevention device that can block the fluid path. (2) The pressurizing device includes a pressurizing hydraulic cylinder connected to the brake pedal so as to be able to operate the brake pedal, and a pressurizing hydraulic cylinder that is controlled by the electronic control device to act on the piston of the pressurizing hydraulic cylinder. a pressurizing control valve that can change the applied force, and the pressure reducing device includes a pressure reducing hydraulic cylinder that can change the braking fluid pressure with respect to the wheels, and a piston of the pressure reducing cylinder that is controlled by the electronic control device. The wheel slip prevention device according to claim 1, further comprising a pressure reducing control valve capable of changing the force acting on the wheel slip prevention device. (3) Claims further comprising a brake switch capable of detecting that the brake pedal is operated by a driving action by a driver, and information from the brake switch is supplied to the electronic control device. The wheel slip prevention device according to item 1 or 2.