JPH02212253A - Stoppage holding device for vehicle - Google Patents

Abstract

PURPOSE:To prevent generation of impact noise by driving and controlling an electromagnetic valve to intermittently attract its valve body to quietly seat it on a valve seat at the time of closing the electromagnetic valve in a device that brake operating condition is maintained by closing a passage in a brake booster by means of the electromagnetic valve. CONSTITUTION:A brake booster (A), when a brake pedal is stepped on to move a valve plunger 13 forward, shuts off between a vacuum line 8 and an atomosphere line 9 by means of a valve mechanism 7 and communicates the atomosphere line 9 and an atomosphere line 10 to move a power piston 2 forward due to differential pressure between a pressure changing chamber 5 and a pressure constant chamber 4. And an electromagnetic valve 21 is closed to shut off the vacuum line for maintaining a brake under braking condition. In this case, when it is judged that operational conditions to close the electromagnetic valve 21 is effected in the operation judging unit 31 in a control unit 29, indicating voltage is output from an intermittently attracting drive unit 35 to a constant current circuit 28 to intermittently effect electricity condition applied to the solenoid coil 22 of the electromagnetic valve 21 to quietly seat a valve body on a valve seat 25.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a vehicle stop-keeping device, and more particularly, to a vehicle stop-keeping device using a brake booster ft-.

``Prior art'' Conventionally, as a stop-holding device for a vehicle using a brake booster%, a solenoid valve that opens and closes a vacuum passage is attached to the pulp body, and a solenoid valve that opens and closes a vacuum passage is attached to the pulp body under certain conditions such as when the vehicle is stopped for a continuous period of time. There is a known system in which the brake booster is maintained in an activated state by closing the electromagnetic valve when the above condition is satisfied, thereby allowing the brake to continue to be activated even after the brake pedal is released. (Japanese Unexamined Patent Publication No. 62-279164).

In other words, a negative pressure brake booster generally includes a power piston slidably disposed within a shell, a valve mechanism housed within a pulp body of the power piston shaft, and a valve mechanism formed on the front side of the power piston in the operating direction. a constant pressure chamber into which negative pressure is constantly introduced; a variable pressure chamber formed on the rear side into which atmospheric pressure is introduced; and a passageway formed in the pulp body and communicating the constant pressure chamber and the variable pressure chamber via the valve mechanism. and a passage communicating between the atmosphere and the variable pressure chamber, and an input shaft that operates a valve brusher constituting the valve mechanism to switch the flow path and supply atmospheric pressure to the variable pressure chamber to advance the power piston; It is equipped with an output shaft that moves on the pulp body, and the pedal force applied to the input shaft via the brake pedal is boosted, making it possible to perform a strong braking action with a light pedal force. .

In snowmaking that uses this type of brake booster M to keep a vehicle stationary, a solenoid valve is placed in the constant pressure chamber and attached to the pulp body, and the solenoid valve applies a constant pressure through the valve mechanism. A passage communicating between the chamber and the variable pressure chamber is opened and closed.

In the case of snowmaking with this configuration, if the solenoid valve is left open, the same operation as a normal brake booster can be obtained, and when the vehicle stops due to braking, the required If the above-mentioned solenoid valve is closed when the above condition is satisfied, the above-mentioned solenoid valve will close even if the brake action is released and the variable pressure chamber and the constant pressure chamber are to be communicated through the above-mentioned valve mechanism and passage. Therefore, the atmospheric pressure introduced into the variable pressure chamber cannot escape to the negative pressure source via the constant pressure chamber. Therefore, even if the pedal force is released from the brake pedal, the braking action can be continued.

Conventionally, when closing the solenoid valve, a control device applies current to the solenoid coil of the solenoid valve, attracts the valve body of the solenoid valve, and seats it on the valve seat. ! I was trying to close my eyes.

"Problem to be Solved by the Invention" However, if the valve element is seated on the valve seat by simply applying current to the solenoid coil, an impact noise is generated when the valve element is seated on the valve seat. In addition, there was a risk that the durability of the valve body and valve seat would be reduced due to the impact upon seating.

"Means for Solving the Problems" In view of such circumstances, the present invention provides the above-mentioned stop-holding snowmaking system, in which the control device controls the energization state of the solenoid coil when the solenoid valve is closed. An intermittent suction drive unit is provided that intermittently suctions the valve body to gently seat it on the valve seat.

"Operation" According to the above configuration, the intermittent suction drive section of the control device, when the solenoid valve is closed, intermittently suctions the valve body while controlling the energization of the solenoid coil, for example, ON-OFF, to gently valve the valve. Since the valve body is seated on the valve seat, it is possible to prevent the occurrence of impact noise when the valve body is seated on the valve seat, and it is also possible to prevent the durability of the valve body and the valve seat from decreasing due to the impact.

``Embodiment'' The present invention will be described below based on the illustrated embodiment. In FIG. A diaphragm 3 is stretched between the shell 1 and the power piston 2 and the diaphragm 3 to partition the interior 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 is housed in a pulp body 6 provided in a detail of the power piston 2, and this valve mechanism 7 includes a vacuum passage 8 communicating with the constant pressure chamber 4 and an atmospheric passage communicating with the variable pressure chamber 5. 9, and an atmosphere introduction passage 1 that roughly communicates with the atmosphere.
The state of communication with 0 is switched and controlled.

The valve plunger 13 constituting the valve mechanism 7 is the key member 1
4 prevents the pulp body 6 from coming out, and its end is connected to an input shaft 15 that is linked to a brake pedal (not shown), and the tip of the plunger 13 is connected to a rear crayon disc 16! Via Bush Rod 1
It is linked to 7.

The power piston 2, pulp body 6, etc. are normally held in the non-operating position shown in the figure by a return spring 18, and in this state, the valve mechanism 7 connects the vacuum passage 8 and the atmospheric passage 9, and also connects the atmospheric passage 9 with the atmospheric passage 9. The communication with the atmosphere introduction passage 10 is disconnected, thereby the negative pressure introduction pipe 1
The negative pressure that is constantly introduced into the constant pressure chamber 4 through the vacuum passage 9 is introduced into the variable pressure chamber 5 through the vacuum passage 8 and the atmospheric passage 9.

On the other hand, when the brake pedal is depressed and the valve plunger 13 is moved forward, the valve mechanism 7 disconnects the communication between the vacuum passage 8 and the atmosphere passage 9, and also connects the atmosphere passage 9 and the atmosphere introduction passage 10. As a result, the atmosphere is introduced into the variable pressure chamber 5 from the atmosphere introduction passage 10 through the atmosphere passage 9, so that the power piston 2, pulp body 6, etc. are moved forward against the retardation spring 18. Become.

Therefore, the solenoid valve 2 for maintaining the brake in the operating state
1 is disposed in the constant pressure chamber 4 and attached to the pulp body 6 at the outer and lower position of the water spring 1, and the solenoid coil 22 of the solenoid valve 21 is energized to attract the valve body 23. When actuated, the valve body 23 is seated on a valve seat 25 against a spring 24, thereby closing the vacuum passage 8.

The harness 26 pulled out from the solenoid coil 22 is kept airtight by the sealing means 27 and then pulled out to the outside of the shell 1, and then passed through the constant current circuit 28 to the solenoid valve 21.
It is connected to a control device @29 consisting of a micro combi coater etc. that controls opening and closing.

The solenoid valve 21 is maintained in an open state [(here,
It is clear that braking can be effected by depression and release of the brake pedal, similar to brake boost snowmaking known in the art. On the other hand, if the solenoid valve 21 is operated to close the vacuum passage 8 in the operating state of the brake booster MA when the brake pedal is depressed, the pressure will change even if the brake pedal is subsequently released. The pressure fluid in the chamber 5 cannot escape to the constant pressure chamber 4, and the power piston 2, pulp body 6, etc. located at the operating position are maintained at the same position, and the brake operating state is maintained.

Next, the control device 29 includes an operation determination unit 31 which determines whether an operating condition for closing the electromagnetic valve 21 and a release condition for opening the electromagnetic valve 21 are satisfied. The operation determination unit 31 includes a brake switch 32 that detects whether or not the brake pedal is depressed, a clutch switch 33 that detects that the clutch is engaged, and a push button that activates the stop holding device 1. A signal from the actuation switch 34 is input.

The operation determination section 31 operates to close the solenoid valve 21 when the operation switch 34 is pressed by the driver while the brake switch 32 detects that the brake pedal is depressed. It is now determined that the condition has been met, and from that state,
When the clutch switch 33 detects that the clutch is connected, it is determined that the release condition for opening the electromagnetic valve 21 is satisfied.

When the operation determination unit 31 determines that the operation condition is satisfied, the operation determination unit 31
5 outputs a command voltage to a constant current circuit 28, and when the command voltage is applied, the constant current circuit 28 energizes the solenoid coil 22 with a constant value of current according to the magnitude of the command voltage, and operates the solenoid valve 21. Make it close.

Further, when the operation determination unit 31 determines that the release condition is satisfied from the closed state of the solenoid valve 21, the operation determination unit 31 stops the excitation of the solenoid coil 22 by the intermittent suction drive unit 35, and causes the valve body 23 of the solenoid valve 21 to is opened by a spring 24.

By the way, when the solenoid valve 21 is closed, the intermittent suction drive unit 35 intermittently sucks the valve body 23 to gently seat it on the valve seat 25, and after seating the valve body 23 at the valve pressure 25, By lowering the command voltage to the constant current circuit 28 and lowering the constant current iI applied to the solenoid coil 22 from the constant current circuit 28, it is possible to prevent the solenoid coil 22 from burning out.

That is, as shown in FIG. 2, the intermittent suction drive section 35
is a suction instruction voltage v1 of a sufficient magnitude to cause the valve body 23 to actuate suction at the start of suction T, and for a predetermined suction time T1.
After a predetermined rest time T2 has elapsed, the suction command voltage V+ is output again for a predetermined suction time T3, and roughly after a predetermined rest time T4 has elapsed, it is output for a predetermined suction time Ts. I am doing one thing to do. At this time, it goes without saying that the lengths of the above-mentioned times T and -T are set so that the valve body 23 can be seated gently on the valve seat 25.

After the valve body 23 is seated on the valve seat 25, the intermittent suction drive unit 35 continues to seat the valve body 23 on the valve seat 25, although it is not large enough to operate the valve body 23 by suction. By continuously outputting the holding instruction voltage V2 as large as possible, it is possible to prevent the solenoid coil 22 from burning out due to the continuous output of the large attraction instruction voltage V.

In the above configuration, when the operation determination section 31 of the control device 29 determines that the operation condition for closing the solenoid valve 21 is satisfied, that is, the brake switch edge 32 detects that the brake pedal is depressed. In this state, when the operation switch 34 is pressed by the driver, the operation determination section 31 outputs this to the intermittent suction drive section 35.

Then, the intermittent suction drive unit 35 maintains the suction instruction voltage v1 for a predetermined suction time T+T3 with each pause time T2 and T4 in between.
, Ts. As a result, the valve body 23 of the solenoid valve 21
does not suddenly sit on the valve seat 25 as shown by the imaginary line in FIG. 2, but '5i7!' in the same figure. , ta, the valve body 23 is seated gently on the valve seat 25, so that it is possible to prevent the generation of impact noise when the valve body 23 is seated on the valve seat 25, and also to prevent the valve body 23 and the valve body 23 due to the impact from being generated. Deterioration in the durability of the valve seat 25 can be prevented.

When the final suction time T, which is sufficient for the valve body 23 to sit on the valve seat 25, has elapsed, the intermittent suction drive unit 3
5 switches the suction instruction voltage V to a smaller holding instruction voltage V2 to prevent the solenoid coil 22 from burning out.

Next, when it is detected that the clutch is connected by the clutch switch 33 after a smooth start on a hill from the stopped state, for example, the operation determination section 31 determines that the release condition is satisfied. Then, the output of the holding instruction voltage V2 by the intermittent suction drive section 35 is stopped, the solenoid valve 21 is opened, and the above-mentioned stopped holding state is released.

Note that the length of each of the above-mentioned times T1 to T5 does not always have to be constant, and depending on the configuration of the control device 29 and constant current circuit 28, the length of each time T1 to T5 may be set to be optimal according to fluctuations in the power supply voltage. It is also possible to vary it.

"Effects of the Invention" As described above, according to the present invention, the intermittent suction drive section of the control device controls the energization of the solenoid coil when the solenoid valve is closed, and intermittently suctions the valve body to gently Since it is seated on the valve seat, it is possible to prevent the generation of impact noise when the valve body is seated on the valve seat, and it is also possible to prevent the durability of the valve body and valve seat from decreasing due to the impact. is obtained.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing one embodiment of the present invention, and FIG. 2 is a characteristic diagram illustrating the operating state. 6.-Pulp body 8.-Passage 21-.Solenoid valve 22.-Solenoid coil 2
3.-Valve body 25-.Valve seat 29-..Control device 31--Operation determination section 35.--Intermittent suction drive section A..-Brake booster T+ Ts, Ts--Suction time T2, T4--Stop Time patent applicant Jidosha Kiki Co., Ltd.

Claims (1)

[Claims] A solenoid valve that is provided in the pulp body of the brake booster and closes a passage formed in the pulp body to maintain the brake booster in a brake operating state, and a solenoid coil of the solenoid valve that is energized. and a control device for suctioning the valve body of the solenoid valve to seat it on the valve seat and closing the passage, wherein the control device includes a control device that controls the solenoid coil when the solenoid valve is closed. A stop-holding device for a vehicle, comprising an intermittent suction drive unit that controls the energization state and intermittently suctions the valve body to gently seat it on the valve seat.