JPH01317859A - Auxiliary equipment for slope starting of vehicle - Google Patents

Abstract

PURPOSE:To facilitate a slope starting by providing a switching valve opened at the car stopping time of stepping a brake pedal and clutch pedal on an ascent and continuing in the brake working state of a brake booster by the pressure fluid fed through this switching valve. CONSTITUTION:A brake assistor A cuts off the communication of a constant pressure chamber 4 and sliding pressure chamber 5 by actuating a valve mechanism 7 with the stepping of a brake pedal 24 and a valve body 6 is moved to the left part by leading the fluid pressure into the sliding pressure chamber 5 and a brake master cylinder is worked via a push rod 26 accordingly. In this case, the 1st switching valve 16 closed at the pressure fluid feeding time is provided on the passage 15 communicating the valve mechanism 5 and constant pressure chamber 4. On this 1st switching valve 16 the flow passage switching valve 41 feeding a pressure fluid at the stepping time of a clutch pedal 40 is also provided. Moreover the 2nd switching valve 39 released in case of a vehicle being inclined at more than the specified value on an ascent is interposed on the passage 36 communicating both valves 16, 41.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a slope start assist device using a brake booster, and particularly to a slope start assist device suitable for manual transmission vehicles.

"Prior Art" In general, a brake booster operates a valve mechanism when the brake pedal is depressed to cut off communication between a constant pressure chamber and a variable pressure chamber, and introduces fluid pressure into the variable pressure chamber to perform brake operation. Further, when the brake pedal is released, the constant pressure chamber and variable pressure chamber are communicated via the valve mechanism, and the fluid pressure introduced into the variable pressure chamber is released to the constant pressure chamber, thereby canceling the brake operation.

Conventionally, as a hill start assisting device using a brake booster, a device is known in which an electromagnetic on-off valve is provided in a passage communicating between the valve mechanism and a constant pressure chamber (Japanese Patent Laid-Open No. 1982-2
No. 79164), by closing the passage with the electromagnetic on-off valve, communication between the constant pressure chamber and the variable pressure chamber can be continuously cut off even when the brake pedal is released. Brake operation can be continued by preventing fluid pressure from escaping into the constant pressure chamber.

"Problem to be Solved by the Invention" By the way, when an electromagnetic on-off valve is attached to the above-mentioned valve body, the axial dimension of the brake booster must be adjusted by 1° so that the electromagnetic on-off valve does not interfere with the inner wall of the shell. Therefore, in order to suppress the increase in the axial dimension, it is desirable to reduce the axial dimension of the electromagnetic on-off valve.

In order to reduce the axial dimension of a solenoid valve, it is effective to reduce the axial dimension of the solenoid coil, but if the number of turns of the solenoid coil is reduced for this purpose, the attraction force of the solenoid coil will decrease. However, there are certain limits to its miniaturization. On the other hand, if the current applied to the solenoid coil is increased in order to compensate for the decrease in the suction force of the solenoid coil due to a decrease in the number of turns of the solenoid coil, the amount of heat generated will increase, which will reduce the durability of the diaphragm and valve body. will have a negative impact on

In addition, the hill start assist device is especially necessary when starting a vehicle on an uphill slope, but if you try to activate the hill start assist device only when starting on an uphill slope, it may cause the vehicle to stop. Requires a vehicle speed sensor to detect a vehicle speed, an inclination sensor to detect an uphill slope, a clutch sensor to detect that the clutch is engaged when starting, and a control device to manually control the opening and closing of the electromagnetic on-off valve using signals from these sensors. Therefore, the configuration was complicated and expensive.

"Means for Solving the Problem" In view of such circumstances, the present invention operates a valve mechanism by pressing the brake pedal to cut off communication between the constant pressure chamber and the variable pressure chamber, and introduces fluid pressure into the variable pressure chamber. A brake that causes a brake to be actuated by pressing the brake pedal, and also communicates a constant pressure chamber and a variable pressure chamber through the valve mechanism when the brake pedal is released, and releases fluid pressure introduced into the variable pressure chamber to the constant pressure chamber to release the brake. a booster, a first on-off valve that is provided in a passage that communicates the valve mechanism and the constant pressure chamber and that closes the passage when pressure fluid is supplied; A flow path switching valve that supplies pressurized fluid, and a second on-off valve that is provided in a passage that communicates the flow path switching valve and the first on-off valve and is opened when the vehicle tilts more than a required value due to an uphill slope. This device constitutes a slope start assist device for a vehicle.

"Operation" According to the above configuration, when the vehicle is stopped by depressing the brake pedal and the clutch pedal on an uphill slope of a required slope, the second on-off valve is released, so the flow path switching is performed in conjunction with the clutch pedal. Pressure fluid is supplied from the valve to the first on-off valve via the second on-off valve. Then, the first opening/closing valve is closed, so even if the brake pedal is released from this state, the pressure fluid introduced into the variable pressure chamber of the brake booster cannot escape to the constant pressure chamber, and therefore the brake operating state remains unchanged. Continued.

Alternatively, when the vehicle is stopped on an uphill slope with the parking brake applied, the brake pedal is depressed to activate the brake booster and release the parking brake, and then when the clutch pedal is depressed. Since the first on-off valve is also closed, even if the brake pedal is released from this state, the brake booster continues to operate the brake.

From this state, if you shift the shift lever to a low gear and release the clutch pedal while depressing the accelerator pedal, the release of the clutch pedal will cause the first
Since the supply of pressure fluid to the on-off valve is stopped, the first on-off valve is opened and the pressure fluid in the variable pressure chamber escapes into the constant pressure chamber, thereby canceling the brake operation by the brake booster. Therefore, the vehicle can be started smoothly.

Since the first on-off valve can obtain a large biasing force depending on the size of the pressure fluid supplied to it,
The axial dimension of the on-off valve can be reduced compared to conventional electromagnetic on-off valves, and since the above-mentioned on-off valves do not generate heat like electromagnetic on-off valves, there is no adverse effect of heat on the diaphragm or valve body. can be completely eliminated.

``Embodiment'' The present invention will be described below with reference to the illustrated embodiment. In FIG. 1, a shell 1 of a brake booster A consists of a front shell la and a rear shell lb, and a power piston 2 is slid into the shell 1. A diaphragm 3 is provided on the back of the power piston 2, and the power piston 2 and diaphragm 3 partition the inside of the shell 1 into a constant pressure chamber 4 at the front and a variable pressure chamber 5 at the rear. .

A valve mechanism 7 for switching the flow path is housed in a valve body 6 integrally provided on the shaft of the power piston 2, and the power piston 2, valve body 6, etc. are moved by a return spring 8 to the non-operating position shown in the figure. It is held in

The valve mechanism 7 includes a first valve seat 1 formed on the valve body 6.
0, a second valve seat 12 formed on the valve plunger 11, and a valve body 14 that is pressed against both valve seats 1O112 from the rear side of the power piston 2, that is, from the right side in FIG. 1 by the elastic force of a spring 13. We are prepared. And the first valve seat 10
The passage 15 and the first
It communicates with the constant pressure chamber 4 through an on-off valve 16, and further communicates the constant pressure chamber 4 with a negative pressure source such as an engine intake manifold (not shown) through a negative pressure introduction pipe 17 provided in the shell 1.

On the other hand, the first valve seat 1G, the valve body 14, and the second valve seat 1
2 and the valve body 14, the valve body 6
It communicates with the variable pressure chamber 5 through a passage 18 formed in the same direction, and further communicates with the atmosphere through a passage 20 provided with a filter 19 inside the seat portion between the second valve seat 12 and the valve body 14. The variable pressure chamber 5 is kept airtight from the outside by a seal member 21 that slidably passes through the valve body 6.

The valve plunger 11 constituting the valve mechanism 7 is a key member 2
3 prevents it from coming out of the valve body 6, and its distal end is connected to the input shaft 25 linked to the brake pedal 24, and the distal end surface of the valve plunger 11 is opposed to the distal end surface of the bushing rod 26. A reaction disk 27 is interposed between the opposing surfaces. Further, a cylindrical portion IC is formed on the shaft portion of the front shell la to protrude toward the inside of the shell 1, and the bushing rod 26 is slidably passed through a seal member 28 disposed inside the cylindrical portion IC. It is made to protrude to the outside of the shell 1, and its protruding end is interlocked with a piston of a master cylinder (not shown).

The first on-off valve 1B is disposed within the constant pressure chamber 4 and is attached to the valve body 6 at a position outside and below the coiled return spring 8. 6 allows the passage 15 formed in the valve body 6 to be opened and closed.

As shown enlarged in FIG. 2, the first on-off valve 16 is
The valve seat 30 includes a valve seat 30 that surrounds the opening of the passage 15 to the constant pressure chamber 4, and a casing 31 that covers the valve seat 30. The casing 31 accommodates a valve body 32 that is seated on the valve seat 30, and the small diameter portion 3 at the right end of the valve body 3z
2a is slidably fitted into the guide hole 6a formed on the valve body 6 side, so that the valve body 32 is fitted into the casing 3.
It is guided so that it can reciprocate in the axial direction of 1.

A spring 33 is provided between the valve element 32 and the valve body 6.
Normally, the valve body 32 is separated from the valve seat 30, and in this state, the passage 15 is connected to the constant pressure chamber through the gap between the valve seat 30 and the valve body 32 and the opening 31a formed in the casing 31. It is connected to 4.

A diaphragm 34 is attached to the left end face of the valve body 32, and by attaching the outer periphery of the diaphragm 34 to the stepped portion of the casing 31 while keeping it airtight, the left end of the diaphragm 34 can be Pressure chamber 3 inside casing 31
5 is formed. When pressure fluid is introduced into the pressure chamber 35, the valve body 32 is brought into contact with the valve seat 30 against the spring 33, thereby closing the passage 15.

One end of a flexible conduit 36 attached to the casing 31 is communicated with the pressure chamber 35.
The other end of 6 is wound spirally in constant pressure chamber 4, and then
As shown in the figure, a grommet 38 provided in an opening 37 of the front shell la maintains airtightness and extends the opening 37 to the outside of the shell 1. The conduit 36 drawn out to the outside of the shell 1 is connected to a second on-off valve 39 that is opened when the vehicle tilts more than a required value due to an uphill slope, and a first on-off valve I6 that is linked to the clutch pedal 40 and is opened when the clutch pedal is depressed. It is connected to the above-mentioned intake manifold via a flow path switching valve 4I that supplies pressure fluid, that is, atmospheric pressure, to the intake manifold.

The second on-off valve 39 includes a bottomed cylindrical housing 42, and one end opening of the housing 42 is connected to a plug 43.
By closing the housing, a pressure chamber 44 is formed inside the housing. Then, at both ends of this pressure chamber 44, first
A passage 42a and a second passage 42b are formed, and each passage 42a
, 42b, the first on-off valve 16 is communicated with the flow path switching valve 41 via the first passage 42a, the pressure chamber 44, and the second passage 42b.

Inside the pressure chamber 44 is a valve seat 45 surrounding the first passage 42a.
and a spherical valve body 4 seated on the valve seat 45.
6 is housed in a freely removable manner, and the valve body 46 is normally connected to the valve seat 4 via a pressure contact member 47 that is brought into contact with the valve body 46.
5 is provided with a spring 4B to hold it in the seated position. The second on-off valve 39 is attached to the vehicle with the valve seat 45 facing forward in the direction of travel of the vehicle, and horizontally or with the valve seat 45 side facing slightly upward.

Therefore, when the vehicle is stopped horizontally or on a downhill slope, the valve body 46 is seated on the valve seat 45a by the elastic force of the spring 48, so that the first on-off valve 16 and the flow path switching valve 41 are seated on the valve seat 45a.
Communication with is cut off. On the other hand, when the vehicle is stopped on an uphill slope of a predetermined slope or higher, the valve body 46 moves off the valve seat 45a against the elastic force of the spring 48 due to the weight of the valve body 46 and the pressure contact member 47. Therefore, the first on-off valve 16 and the flow path on-off valve 41 are brought into communication.

Further, even if the second on-off valve 39 is closed while pressure fluid is introduced into the first on-off valve 16, the first on-off valve 16
In order to allow pressure fluid to escape from the first on-off valve 16 , a bypass passage 49 is provided that bypasses the second on-off valve 39 .
A check valve 50 is provided to allow flow of pressure fluid to the 1.

Next, the flow path switching valve 41 has a stepped through hole 51 in the axial direction.
A housing 51 is provided, and a valve mechanism 52 having substantially the same configuration as the brake booster A is housed within the housing 51. This valve mechanism 52
A first valve seat 53 formed on the end face of the stepped portion of the stepped through hole 51a, a second valve seat 55 formed on the left end face of the valve plunger 54 slidably provided in the housing 51, and A valve body 57 is provided on the valve seat 53, 55 from the left side in FIG. 1 by the elastic force of a spring 56.

The outside of the seat portion of the first valve seat 53 and the valve body 57 is communicated with the intake manifold through a passage 58 formed in the housing 51, and the first valve seat 53, the valve body 57, and the 2. A passage 59 formed in the housing 51 at an intermediate portion between each sealing portion between the valve seat 55 and the valve body 57.
It is communicated with the second on-off valve 39 via. Further, the inner side of the seat portion between the second valve seat 55 and the valve body 57 is communicated with the atmosphere through a passage 61 provided with a filter 60.

The valve plunger 54 is connected to the clutch pedal 40 by a connecting member 62, and under normal conditions when the clutch pedal 40 is not depressed, the valve plunger 54 is connected to the clutch pedal 40.
0 to the inoperative position, and a spring 6 loaded between the valve plunger 54 and the housing 51.
3 moves the valve plunger 54 to the left, brings the second valve seat 55 of the valve plunger 54 into close contact with the valve body 57, and also causes the valve body 57 to separate from the first valve seat 53 against the spring 56. ing.

In this situation, the passage 59 communicating with the second on-off valve 39 is
Since communication with the passage 61 communicating with the atmosphere is cut off and communication with the passage 58 communicating with the intake manifold is established, negative pressure is supplied to the second on-off valve 39.

On the other hand, when the clutch pedal 40 is depressed,
Since the valve plunger 54 is displaced to the right via the connecting member 62, the valve body 57 is seated on the first valve seat 53, and the valve body 57 and the second valve seat 55 of the valve plunger 54 are separated. . In this state, the passage 59 communicating with the second on-off valve 39 is connected to the passage 58 communicating with the intake manifold.
Since the communication with the second on-off valve 39 is cut off and communicated with the passage 61 communicating with the atmosphere, the second on-off valve 39 is supplied with atmospheric pressure as a pressure fluid.

In the above configuration, when the vehicle is running with the brake pedal 24 released, the brake booster A is naturally inactive and no braking action is performed.

When the clutch pedal 40 is depressed to shift gears while driving on a flat land or downhill, the flow path of the flow path switching valve 41 is switched as described above to supply atmospheric pressure to the first on-off valve 16. However, since the second on-off valve 39 located in the middle is closed, atmospheric pressure is not introduced into the first on-off valve 16.

On the other hand, when the clutch pedal 40 is depressed for gear shifting while driving on an uphill slope of a predetermined slope or higher, the second on-off valve 39 is open, so that the atmospheric pressure increases to the first on-off valve 16. will be supplied to

Then, the first on-off valve 16 closes and blocks the passage 15, but
At this time, the brake pedal 24 is not depressed, so even if the passage 15 is closed, the brake booster A remains inactive, and the brakes are not operated. If released, the first
Since the atmospheric pressure that has been supplied to the on-off valve 16 is sucked and discharged to the intake manifold, the first on-off valve 16 is opened.

Next, when the brake pedal 24 is depressed to stop the vehicle, since the second on-off valve 39 is closed on a flat land or downhill, the first on-off valve 16 will not close, and therefore normal brake operation will not be possible. It will be done.

On the other hand, on an uphill slope of a predetermined slope or higher, the brake pedal 2
4 and when the vehicle is stopped by depressing the clutch pedal 40, the second on-off valve 39 opens due to the upward slope, and the passage switching valve 41 is communicated with the atmosphere by depressing the clutch pedal 40. Therefore, atmospheric pressure is supplied to the first on-off valve 16 and the passage 15 is shut off. At this time, since the atmosphere at the required pressure is introduced into the variable pressure chamber 5 by depressing the brake pedal 24, even if the brake pedal 24 is released from this state, the atmospheric pressure introduced into the variable pressure chamber 5 will be reduced. cannot escape to the constant pressure chamber 4 through the passage 15, so the brake operation continues.

In addition, when the vehicle is stopped on an uphill slope with the parking brake applied, the brake pedal 24 is depressed to activate the brake booster A, and the parking brake is released with φ, and then the clutch pedal 40 is depressed.
Since the first on-off valve 16 is also closed when the brake pedal is depressed, even if the brake pedal 24 is released from this state, the brake operation state of the rebrake booster A can be continued.

From this state, shift the shift lever to low gear and press the clutch pedal 40 while depressing the accelerator pedal.
When the clutch pedal 40 is released, the atmosphere that has been supplied to the first on-off valve 16 is sucked and discharged into the intake manifold.
will be opened. Then, the atmospheric air in the variable pressure chamber 5 is discharged into the constant pressure chamber 4, so that the brake operation by the brake booster A is released and the vehicle can be smoothly started.

By the way, the second on-off valve 39 may open even during sudden acceleration, but this does not cause any problem since it is usually not possible for the brake pedal 24 and clutch pedal 40 to be depressed at the same time during sudden acceleration. However, if such a situation should occur, the first on-off valve 1B closes while the brake booster A is in operation, and the acceleration decreases before the clutch pedal 40 is released, causing the second on-off valve to close. 39 may close, and in such a state, the commode 1 on-off valve 16
The atmospheric pressure is then sealed and the brakes continue to operate.

For this reason, in this embodiment, a bypass passage 49 and a check valve 50 are provided to bypass the second on-off valve 39, and when the clutch pedal 40 is released, the atmospheric pressure of the first on-off valve 16 is is discharged to the intake manifold through the bypass passage 49 and check valve 50, thereby making it possible to release the brake operation.

"Effects of the Invention" As described above, according to the present invention, the first on-off valve can obtain a large biasing force according to the size of the pressure fluid supplied to it, so that It is possible to reduce the axial dimension of the on-off valve compared to the above, and it is also possible to manufacture a slope start assisting device that operates only on uphill slopes with a relatively simple configuration.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram showing one embodiment of the present invention, and Fig. 2 is a circuit diagram showing an embodiment of the present invention.
It is an enlarged view of the main part of the figure. 1 - Shell 2 - Power piston 4 Constant pressure chamber 5 - Variable pressure chamber 6 - Valve body 7 - Valve mechanism 16 - First opening/closing valve 24 - Brake pedal 36 -
・Conduit 39--Second on-off valve 40--Clutch pedal 41-Flow path switching valve A-Brake booster patent applicant Jidosha Kiki Co., Ltd.

Claims (1)

[Claims] When the brake pedal is depressed, a valve mechanism is actuated to cut off communication between the constant pressure chamber and the variable pressure chamber, and fluid pressure is introduced into the variable pressure chamber to perform brake operation. a brake booster that communicates the constant pressure chamber with the variable pressure chamber and releases fluid pressure introduced into the variable pressure chamber to the constant pressure chamber to release the brake; and a brake booster provided in the passage communicating the valve mechanism and the constant pressure chamber. , a first for closing the passage when pressure fluid is supplied.
An on-off valve, a flow path switching valve that supplies pressurized fluid to the first on-off valve when the clutch pedal is depressed, and a passage that communicates the flow path switching valve and the first on-off valve. A slope start assisting device for a vehicle, comprising: a second opening/closing valve that is opened when the vehicle slopes by more than a predetermined value.