JPH06255472A - Spool type electromagnetic hydraulic pressure control device - Google Patents

Abstract

PURPOSE:To provide a spool type electromagnetic hydraulic pressure control device which can develop control pressure without delay, and seldom develops improper pressure before starting fluid pressure control. CONSTITUTION:It is detected by a footing detection switch 3O that a brake pedal 20 has been footed, a dither current command signal is outputted from a dither current command circuit 124, so that dither current is supplied to an exciting coil. It is detected by a footing force sensor 128 that the footing force of a brake pedal 20 has come up to a specified value, the supply of dither current is suspended, and concurrently the output of an exciting current command signal is started, which is required to develop control pressure enabling car body deceleration in response to the footing force to be obtained by a basic current command circuit 122. The supply of dither current starts supplying exciting current in response to the footing force of the brake pedal 20, and concurrently makes a spool go ahead without delay, so that control pressure is thereby developed immediately. Since it is good enough that the average value of dither current is even small, improper pressure developed before fluid control starts becomes small.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spool type electromagnetic hydraulic pressure control device, and more particularly to elimination of response delay of control pressure.

[0002]

2. Description of the Related Art A spool type electromagnetic hydraulic pressure control device controls the hydraulic pressure by switching the flow of the liquid by moving the spool, and is known from Japanese Utility Model Laid-Open No. 63-40270. The spool type electromagnetic hydraulic pressure control device is generally
(A) A housing having a high pressure port, a low pressure port, and a control pressure port; and (b) a valve hole in the housing that is slidably and substantially fluid-tightly fitted, and the control pressure port is a high pressure port. (C) An actuating force for actuating the spool in a direction to cut off the control pressure port from the high pressure port by applying a force based on the hydraulic pressure of the control pressure port to the spool and the spool that selectively communicates with the low pressure port. And (d) an exciting coil for controlling the supply current to the exciting coil to apply a control force in the direction opposite to the operating force of the operating force generating means to the spool. And (e) current supply control means for controlling the current supply to the exciting coil. The spool is always kept in the original position where it shuts off the control pressure port from the high pressure port, but if the exciting current is supplied to the exciting coil and the controlling force is applied to the spool by the exciting force, the spool moves. The control pressure port is communicated with the high pressure port, and a control pressure having a height corresponding to the exciting current to the exciting coil is generated in the control pressure port.

In such a spool type electromagnetic hydraulic pressure control device, since there is a frictional resistance between the spool and the housing, when the control pressure is generated, the spool exerts a control force even if a current is supplied to the exciting coil. If the control force applied by the means does not overcome the frictional resistance, the movement does not start, and the control pressure is delayed. Therefore, the applicant of the present invention supplies a constant amount of current to the exciting coil before starting the hydraulic pressure control for generating a control pressure according to the magnitude of the exciting current in the control pressure port, thereby making the spool Developed a device that can start moving without delay and obtain control pressure without delay.

[0004]

However, although the control pressure can be obtained without delay in this way, there is a disadvantage that the pressure is generated in the control pressure port before the execution of the hydraulic control and the pressure is supplied to the actuator. It turned out to occur. In view of such a situation, the present invention does not generate unnecessary pressure in the control pressure port before starting the hydraulic control, or even if it is small, it is possible to generate the control pressure without delay when starting the hydraulic control. It is an object of the present invention to provide a spool-type electromagnetic hydraulic pressure control device capable of achieving the above.

[0005]

The gist of the present invention is to provide (a) housing, (b) spool, (c) actuating force generating means, (d) control force applying means, and (e) current supply control. A dither current supply that supplies a dither current whose magnitude is periodically changed and whose average value is constant to the exciting coil to at least the current supply control means of the spool-type electromagnetic hydraulic pressure control device having means. There is a means.

[0006]

As described above, if the exciting current is increased after supplying the dither current to the exciting coil at least immediately before the hydraulic pressure control is started, the control pressure is generated without delay. Moreover,
The average value of the dither current can be smaller than that when DC current is supplied before starting the hydraulic control, so the pressure generated at the control pressure port can be small before starting the hydraulic control. It can be lost. Further, since the pressure generated by the supply of the dither current is small, it is possible to always supply the dither current in the non-hydraulic pressure control state. Further, the dither current may be supplied not only during non-hydraulic pressure control but also during hydraulic pressure control. In this case,
Since the dither current is superposed on the exciting current to be supplied to the exciting coil, the additional effect of reducing the hysteresis of the hydraulic control characteristic can be obtained. The dither current has an amplitude of 0.05
A current that draws a sine curve of ~ 0.25 amps and a frequency of 100-300 Hertz is desirable.

[0007]

As described above, according to the present invention, it is possible to obtain a spool type electromagnetic hydraulic pressure control device having high responsiveness while avoiding generation of an inconvenient pressure before the hydraulic pressure control is started.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to the drawings, taking as an example the case where the present invention is applied to a spool type electromagnetic hydraulic pressure control device for an automotive hydraulic brake device.

In FIG. 1, 10 and 12 are respectively
The left and right front wheels are front wheel cylinders, and 14 and 16 are rear left and right rear wheel cylinders, respectively. These wheel cylinders 10, 12, 14, 16 are provided with a hydraulic pressure generated in the master cylinder 22 according to the depression of the brake pedal 20 by switching the change valve 18, and an electromagnetic hydraulic pressure based on the depression of the brake pedal 20. The higher of the hydraulic pressures controlled by the control valve 24 is supplied alternatively. The brake fluid pumped up from the reservoir 36 by the pump 38 is always stored in the accumulator 26 in a constant fluid pressure range. A motor 40 drives the pump 38.

In this hydraulic brake device, the wheel cylinders 10, 12, 14, 16 are normally supplied with the hydraulic pressure controlled by the electromagnetic hydraulic pressure control valve 24, but the electromagnetic hydraulic pressure control valve 24 side is abnormal. If cylinder occurs, master cylinder 2
The hydraulic pressure generated in 2 is supplied to secure the braking force. The control pressure of the electromagnetic hydraulic pressure control valve 24 (the hydraulic pressure of the control pressure port 78) is set to be slightly higher than the hydraulic pressure of the master cylinder 22.

The electromagnetic hydraulic pressure control valve 24 has a housing 50 as shown in FIG. The housing 50 has a plurality of blocks fixed therein, and has a bottomed valve hole 52 having a circular cross-sectional shape, and a stepped large space 56 located on the open end side of the valve hole 52. Communicate with each other and are formed concentrically. A spool 58 is fitted in the valve hole 52 so as to be substantially liquid-tight and slidable. Spool 5
8 has a stepped shape, a small diameter portion 64 is formed between the first large diameter portion 60 and the second large diameter portion 62, and the first and second large diameter portions 60,
The first large diameter portion 60 is sized to fit into the valve hole 52 at 62 and to project into the space 56 from the valve hole 52.

The clearance between the outer peripheral surfaces of the first and second large diameter portions 60 and 62 and the inner peripheral surface of the valve hole 52 is as small as 10 μm or less in diameter. An intermetallic seal is formed between them. In the housing 50, a pin hole 66, which is concentric with the valve hole 52 and opens on the bottom surface thereof, has a diameter smaller than the valve hole 52 and has a bottom, is formed, and the reaction force pin 68 is slidably fitted therein. At the same time, the spring 70 projects into the valve hole 52, and the spool 58
Is urged in the direction of abutting against.

The housing 50 further includes a high pressure port 72 connected to the accumulator 26, first and second low pressure ports 74 and 76 connected to the reservoir 36, and a control pressure port 78 connected to the wheel cylinders 10-16.
Are formed. The control pressure port 78 has a spool 58.
Is communicated with an annular chamber 80 formed by the small diameter portion 64 of the valve hole 52 and the inner peripheral surface of the valve hole 52, and the high pressure port 72 is an annular ring formed in a portion on the bottom side of the control pressure port 78 of the valve hole 52. It communicates with the groove 82.

The first low pressure port 74 is communicated with the bottom of the valve hole 52, and the second low pressure port 76 is an annular groove 84 formed on the opening side of the valve hole 52 with respect to the control pressure port 78 of the valve hole 52. Is in communication with. Further, the pin hole 66
A liquid passage 86 branched from the control pressure port 78 is connected between the bottom surface of the reaction force pin 68 and the reaction force pin 68.
Receives the hydraulic pressure of the control pressure port 78 and causes an operating force based on the hydraulic pressure to act on the spool 58, thereby generating an operating force in a direction of blocking the communication between the high pressure port 72 and the control pressure port 78. In this embodiment, the reaction force pin 68 and the liquid passage 86 constitute the operating force generating means.

The valve hole 52 of the first large diameter portion 60 of the spool 58.
The ends of the diaphragm 90 are respectively locked to the protrusions from the inside and the inner peripheral surface of the space 56, and the space 56 communicates with the drain chamber 94 communicated with the reservoir 36 by the drain port 92 and the air. It is divided into a filled air chamber 96. A force motor 98 is provided in the air chamber 96. The drain chamber 94 includes a first large diameter portion 60 and a valve hole 62.
Brake fluid leaking from the metal-to-metal seal between and flows in, and returns to the reservoir 36 through the drain port 92.

A small-diameter threaded portion 99 is provided at the end of the spool 58 protruding from the valve hole 52. The exciting coil 100 of the force motor 98 is held by a holding member 106 made of a non-magnetic material, which is fixed to the screw portion 99, and is fitted into an annular groove 110 formed in the yoke 108. The yoke 108 includes a permanent magnet 112, and the holding member 10
6 is on the magnetic path of the permanent magnet 112. Excitation coil 100
Is longer than the axial length of the portion of the yoke 108 facing the outer peripheral surface of the exciting coil 100, and the exciting coil 100 projects to both sides of the magnetic field formed by the permanent magnet 112. There is.

When the exciting current is not supplied to the exciting coil 100, the spool 5 is urged by the spring 70.
2 is maintained in its original position communicating the control pressure port 78 with the second low pressure port 76 as shown in FIG. When an exciting current is supplied to the exciting coil 100, the exciting coil 10
0 is pushed out from the yoke 108 by the magnetic field of the permanent magnet 112. When the exciting coil 100 moves forward, the spool 5
8 is advanced into the valve hole 52. A force for connecting the control pressure port 78 to the high pressure port 72 on the spool 58,
That is, a control force in the opposite direction to the actuation force generated based on the control pressure applied by the reaction force pin 68 is applied, and the force motor 98 constitutes a control force application means.

The magnitude of the exciting current supplied to the exciting coil 100 is commanded by the controller 120 shown in FIG. The controller 120 has a basic current command circuit 122,
A dither current command circuit 124 and an adder 126 are provided. The basic current command circuit 122 and the dither current command circuit 124 are each supplied with a detection signal of a pedaling force sensor 128 for detecting the pedaling force of the brake pedal 20, and the dither current command circuit 124 is further depressed to detect the pedaling of the brake pedal 20. The detection signal of the detection switch 130 is supplied.

The basic current command circuit 122 adds an exciting current command signal for obtaining a deceleration to be generated in the vehicle body according to the pedaling force of the brake pedal 20 to the adder 126.
Output to. In addition, the dither current command circuit 124 has an amplitude of 0.15 to
A dither current command signal that draws a sine curve of 0.2 amperes and a frequency of 150 hertz is output to the adder 126, and when the pedal force detected by the pedal force sensor 128 exceeds a set value, the output of the dither current command signal is stopped. Adder 1
The reference numeral 26 supplies the sum of the command signals from the basic current command circuit 122 and the dither current command circuit 124 to the operation amplifier 132, and the commanded current is supplied from the operation amplifier 132 to the exciting coil 100.

In the hydraulic brake device constructed as described above, no current is supplied from the operational amplifier 132 to the exciting coil 100 during normal operation when the brake pedal 20 is not depressed. Therefore, the electromagnetic hydraulic control valve 24
2, the spool 58 is in the original position shown in FIG. 2, and in this state, the second low pressure port 76 and the control pressure port 78 are communicated with each other via the annular chamber 80, and the wheel cylinder 10
The hydraulic pressures of ˜16 are equal to the atmospheric pressure which is the hydraulic pressure of the reservoir 36.

When the depression operation of the brake pedal 20 is started, the start is detected by the depression detection switch 130 and the depression force of the brake pedal 20 is detected by the depression force sensor 128. Stepping detection switch 1
The dither current command circuit 124 issues a dither current command signal in response to the detection signal of 30, and supplies the dither current to the exciting coil 100. When the depression force of the brake pedal 20 reaches the set value, the dither current command circuit 124 stops outputting the dither current command, while the basic current command circuit 12
Reference numeral 2 starts to output an exciting current command signal for obtaining a deceleration of a height corresponding to the depressing force of the brake pedal 20, and thereafter, the exciting current corresponding to the depressing force of the brake pedal 20 is applied to the exciting coil 1.
00 is supplied. In the present embodiment, the hydraulic pressure control is started when the pedal effort of the brake pedal 20 reaches the set value.

The change in the exciting current supplied to the exciting coil 100 is shown in the graph of FIG. As is apparent from this graph, the dither current is supplied to the exciting coil 100 after the depression of the brake pedal 20 is started until the depression force of the brake pedal 20 reaches the set value, and thereafter, the brake pedal 2 is pressed.
An exciting current corresponding to a pedaling force of 0 is supplied to the exciting coil 100.

When the exciting current corresponding to the pedaling force of the brake pedal 20 is supplied to the exciting coil 100, the spool 58 is advanced and the communication between the second low pressure port 76 and the control pressure port 78 is cut off, and the spool 58 is cut off. Is further advanced, the high pressure port 72 and the control pressure port 78 are connected to each other in the annular chamber 8.
The hydraulic pressure of the control pressure port 78 rises and the hydraulic pressure control of the wheel cylinders 10 to 16 is performed. The spool 58 stops at a position where the operating force and the control force applied in opposite directions are balanced with each other, and the control pressure is controlled to a height at which deceleration corresponding to the pedaling force is obtained.

When the depression of the brake pedal 20 is started, the supply of the dither current to the exciting coil 100 is started, and the exciting current based on the depression force of the brake pedal 20 is supplied until the supply of the exciting coil 100 is started. Therefore, the spool 58 starts to move forward simultaneously with the start of the supply of the exciting current based on the pedaling force of the brake pedal 20, and the control pressure corresponding to the depression of the brake pedal 20 can be obtained without delay.

The average value of the dither current is the spool 5
8 and the reaction force pin 68 and the housing 50 are sized to generate a force in the force motor 98 that is just balanced with the frictional force between the housing 50 (which is reduced by the dither current) and the set load of the spring 70. Therefore, the control pressure is not generated in the control pressure port 78, and the wheel cylinders 10-1 to 10-1 are started before the hydraulic pressure control is started even though the pedaling force of the brake pedal 20 has not reached the set value.
Brake pressure is never supplied to 6.

If the stepping force of the brake pedal 20 is weakened, the current value supplied from the operation amplifier 132 is reduced based on the instruction of the controller 120, and the forward force of the spool 58 becomes smaller than the reaction force, so that the spool 58 is moved. Is retracted, the control pressure port 78 is communicated with the second low pressure port 76, and the hydraulic pressure in the wheel cylinders 10 to 16 is reduced. When the depression operation of the brake pedal 20 is released, the spool 58 returns to the original position, and the hydraulic pressure of the control pressure port 78 becomes almost atmospheric pressure.

As is apparent from the above description, in this embodiment, the basic current command circuit 1 of the controller 120 is used.
22 constitutes a current supply control means together with the pedal force sensor 128, and the dither current command circuit 124 of the controller 120 constitutes a dither current supply means together with the pedal force sensor 128 and the depression detection switch 130.

In the above embodiment, the supply of the dither current is stopped at the same time when the supply of the electric current based on the pedaling force of the brake pedal 20 is started. However, the depression detection switch 130 depresses the depression of the brake pedal 20. It is also possible to supply the dither current all the time during the detection. By doing so, the effect of reducing the hysteresis of the hydraulic control characteristic due to the decrease in the friction coefficient of the spool can be obtained.

Further, in the above embodiment, the dither current is supplied based on the start of depression of the brake pedal 20, but the dither current is supplied by detecting the release of the accelerator pedal. It is also possible to start the supply of the dither current early in this way.

Further, the control force applying means is not limited to the force motor, but may be constituted by a solenoid and a yoke magnetized by supplying an exciting current to the solenoid to cause the magnetic attraction force to act on the spool as a control force.

In addition, the present invention can be implemented in various modified and improved modes based on the knowledge of those skilled in the art.

[Brief description of drawings]

FIG. 1 is a system diagram of a hydraulic brake device having a spool type electromagnetic hydraulic pressure control device according to an embodiment of the present invention.

FIG. 2 is a front sectional view of the electromagnetic hydraulic pressure control device.

FIG. 3 is a graph showing an exciting current supplied to an exciting coil of the electromagnetic hydraulic pressure control device.

[Explanation of symbols]

 24 Electromagnetic Hydraulic Control Valve 50 Housing 58 Spool 68 Reaction Force Pin 72 High Pressure Port 74 First Low Pressure Port 76 Second Low Pressure Port 78 Control Pressure Port 86 Liquid Passage 98 Force Motor 100 Excitation Coil 120 Controller 122 Basic Current Command Circuit 124 Dither Current Command circuit

Claims (1)

[Claims] 1. A housing having a high pressure port, a low pressure port, and a control pressure port, and a valve hole in the housing, which is slidably and substantially fluid-tightly fitted, and which connects the control pressure port to the high pressure port. And a spool that selectively communicates with the low pressure port, and an actuating force that operates the spool in a direction to shut off the control pressure port from the high pressure port by applying a force based on the hydraulic pressure of the control pressure port to the spool. A control force applying means for applying a control force in the direction opposite to the operation force of the operating force generation means to the spool by controlling the supply current to the exciting coil; In a spool type electromagnetic hydraulic pressure control device including a current supply control means for controlling current supply to an exciting coil, the current supply control means is provided with at least immediately before starting hydraulic pressure control. Size periodically fluctuates, the average value of the spool type solenoid fluid pressure control apparatus characterized in that a dither current supply means for supplying a constant dither current to the exciting coil.