JPS5967147A - Actuator for anti-skid system - Google Patents

Abstract

PURPOSE:To enhance the safety of a brake system upon failure of an anti-skid device, by dipsosing a stopper pin in a small bore opend to a slidable piston hole in the anti-skid device so that the pin is arranged to be projected by spring force upon failure of a control hydraulic pressure system to be engaged with a piston. CONSTITUTION:Hydraulic pressure which is produced from a master cylinder 45 by operating a brake pedal 53, acts a brake 47 through a valve hole 10 to carry out normal brake operation. At this time, if the locking condition of a wheel 46 due to abrupt braking is detected from the output of a rotational speed sensor 48, a controller 49 opens a solenoid valve 37. Thereby, a piston 22 moves to the left, overcoming a spring 35, and therefore, a ball valve 12 closes a valve hole 10. Accordingly, brake hydraulic pressure is cut off to release the brake 47. Further, if a control hydraulic pressure system is failed due to failure of a hydraulic pump 51, a stopper pin 38 is projected by a spring 41 to engage with the stepped part 42 of a piston 22 for nullifying the function of the anti-skid device, thereby the normal function of braking may be ensured.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application This invention relates to an actuator for adjusting brake fluid pressure in an anti-skid device of an automobile.

(b) Prior Art An anti-skid device for a vehicle is a device that prevents the rear wheels from locking during sudden braking and prevents the vehicle body from rolling and spinning, and has been known for a long time.

In such an anti-skid device, as an actuator for adjusting the brake fluid pressure, the actuator body (both pressure receiving surfaces of the housed piston) are connected to the brake fluid pressure and control valve.
The brake fluid pressure AMI regulator, which applies the hydraulic pressure to the brake fluid pressure side and follows the piston control, is also controlled.
@ Hydraulic pressure side (This is provided with a solenoid valve operated by the anti-skid controller, and the anti-skid signal opens the solenoid valve to reduce the control 6111 hydraulic pressure and return the piston.Thus, the brake fluid regulating valve is activated. A basic configuration in which the device is closed is known.

(c) The control fluid pressure that acts on one pressure receiving surface of the intercondylar point piston to be solved by the invention is reduced as described above (when the anti-skid signal is issued from the controller, the pressure is reduced, and as a result, the brake fluid pressure is adjusted). The valve is closed to release the brake pressure, but if an anti-skid device with such a function is installed, the brakes may not work due to a failure in the control hydraulic system. Therefore, it is necessary to provide a so-called fail-safe function that immediately disables the anti-skid function and resumes the normal braking function when a failure of the control 111io occurs in the pressure system.

An object of the present invention is to provide an actuator incorporating such a fail-safe function.

In order to achieve the above-mentioned object, the present invention provides a stopper that is retractable on the wall surface of the control 1 hydraulic chamber, and a means for resolving the intercondylar point. Correct pressure.

The piston 1 is set to be smaller than the normal control pressure, and the piston 1 is provided with an engaging portion for the above stopper, and the position of the stopper described in -1- is adjusted to the above-mentioned engaged position when the piston opens the brake d'li and the pressure regulating valve. The configuration is such that the position is selected so that it can engage with the mating portion.

(e) Examples Examples of the present invention will be described below with reference to the drawings attached.

As shown in Figure 1, the actuator body 1 (here,
A human power port 3 and an output port 4 connected to the brake fluid pressure passage 2, and an anti-skid brake pressure dispersion passage 5 (a human power port and an output port door connected thereto).

are formed, and each of these ports communicates with a cylinder bore 8 provided in the main body 1.

One end of the cylinder bore 8 is closed by a plug 9, and an input hydraulic pressure chamber 11 for brake hydraulic pressure is formed between the valve hole 10 formed by narrowing the bore 8 and the plug 9.
The manpower port 4 is communicated with the hydraulic pressure chamber 11. A ball valve 12 is inserted into the hydraulic pressure chamber 11, and a spring 13 is interposed between the ball valve 12 and the plug 9 to bias the ball valve 12 toward the valve hole 10.

The above-mentioned valve hole 10 (the part of the bore 8 that communicates with this part is formed with a small diameter part 14, a medium diameter part 15, and a lower diameter part 16 in order from the right through a first step part 17 and a second step part 18, respectively. In order to fit each of these parts 14, 15, 16i, the small diameter part 1
9. A piston 22 having a medium-diameter portion 2o and a large-diameter portion 21 is mounted in a single layer such that it can freely slide around the bore 81.

The piston 22 is located in the small diameter portion 14 of the bore 8 to the maximum extent (
In the illustrated state of moving forward to the right, the output port 3 is communicated with the position above that which is blocked by the piston 22, and the cup seal 23 is inserted into the outer circle of the small diameter portion 19 of the piston 22. An output hydraulic pressure chamber 24 is formed between the valve hole 10 and the valve hole 10 . Further, a valve rod 25 is protruded from the tip of the small diameter portion 19 of the piston 22, and comes into contact with the ball valve 12 as shown in the figure when the piston 22 is at its forward limit, thereby opening the valve hole 10.

A communication portion 26 that is thinner than the medium diameter portion 20 is formed between the medium diameter portion 20 and the large diameter portion 21 of the piston 22 . A cup seal 27 is fitted around the outer circle of the medium diameter portion 20, and a manual port is connected to the outer circular bore portion of the communication portion 26 to form a manual pressure chamber 2B.

A communication hole 29 is formed in the communication portion 26, one of which is
An orifice 30 communicating with the small through hole 29 is formed in the center of the large diameter portion 21 of the piston, and a valve chamber 31 protruding from the large diameter portion 21 is formed in the solid portion of the orifice 30.
is stored in this.

The large diameter portion 16 of the bore 8 is closed by a plaque 33,
An output hydraulic pressure chamber 34 is formed between the plaque 33 and the piston large diameter portion 21, and the output port door is communicated with this hydraulic pressure chamber 34. There is a plaque 33 and a screw 1 inside the output hydraulic pressure chamber 34.
- A balance spring 35 is interposed between the large-diameter portion 21 of the spring, and a spring 36 or 1 is inserted between the plaque 33 and the ball valve 32.

Further, a solenoid valve 37 is interposed in the 8i cupboard door 1, and the port 5 is closed in a normal state for towing.

Further, a stopper pin 38 is provided in a portion of the main body 1 in the bore medium diameter portion 15 so as to protrude and retract from the manual liquid juice chamber 28 . The stopper pin 38 is fluid-tightly inserted into the small bore 39 in the direction perpendicular to the pore 8, and
(A spring 41 is interposed between the fitted support plate 40 and the stopper pin 38 is urged in the projecting direction. However, the spring force of the spring 41 is Please set it to be smaller.
Therefore, the human power ttyr+ is in the immersed state as shown in the figure, with normal control fluid pressure acting on the chamber 28.
The movement of the piston 22 is not hindered. The above-mentioned stopper pin 38 is provided at the engagement step portion 42 of the piston 22 at the forward limit as shown in the figure, that is, between the medium diameter portion 20 and the Jlh passage portion 2.
When the stopper pin 38 protrudes from this state, the piston 2
The stopper pin 38 is selected so that it engages with the engagement step 42 when the amount of retraction of the stopper pin 2 is substantially zero.

Note that the first stage portion 17 of the bore 8 is provided with an air vent hole 43 and a filter 44.

The actuators described above are connected together as described below and constitute a part of the anti-skid device.

Person on the brake fluid pressure side of the above actuator] Port 4
(This is the master cylinder 45 via the brake a pressure passage 2.
is connected, and 11. j Cab 3 (The brake 47 of the rear wheel 46 is connected via the moss brake hydraulic passage 2. The rear wheel 461 is provided with a rotation sensor 4B, and its output signal is input to an electronic controller 49t. The controller 49 (in this case, processes the above signals and locks or locks the rear wheels 46).
When detecting the condition, the anti-skid signal is sent to the solenoid valve
7 (This is how it is output.

On the other hand, an accumulator 50 is connected to the manual port on the anti-skid control 1/f& pressure side via a control hydraulic pressure passage 5, and the accumulator 50 is connected to a liquid tank 52 via an LEE pump 51. Further, the output port door is connected to the tank 52 through the city 1 solenoid valve 37 and the control hydraulic pressure passage 5.

Next, the operation of the above actuator will be explained.

[During non-braking and normal braking] (Fig. 1) Since the solenoid valve 37 is closed when not braking, the control Ml/i pressure from the accumulator 50 is distributed equally to the human hydraulic pressure 28 and the output liquid chamber 34. As shown in FIG. 1, the piston 22 is moved to its forward limit state where its stepped portion abuts the first stepped portion 17 of the pore 8, and the valve rod 25 pushes the ball valve 12 to open the valve hole 10. do.

In this case, the ball valve 32 on the control m1 hydraulic pressure side is connected to the spring 3
The spring force 1 of 6 closes the orifice 30, and the stopper pin 38 is in the retracted state due to the controlled hydraulic pressure of the human-powered liquid chamber 28.

In the above state, when the brake pedal 53 is stepped on and hydraulic pressure is generated from the mask cylinder 45, the liquid passes through the valve hole 10 and acts on the brake 47, thereby performing normal braking.

[Anti-skid control all] (Fig. 1, Fig. 2, Fig. 3) When the rotational speed of the rear wheel 46 rapidly decreases due to sudden braking and a locked state or a state close to it is detected through the rotation sensor 48, the controller 49 An anti-skid signal is output from the switch 1 to open the electric shielding valve 37.

By opening the solenoid valve 37, the control MI of the output hydraulic pressure chamber 34 is
When the pressure M suddenly decreases, the balance of the piston 22 (mainly the pressure acting on it (mainly the brake fluid 1-1, the brakes turned off at night, and the spring force of the balance spring 35) changes, causing the balance spring 35 to change. Compress and piston 22
or move to the left. As a result, flake? On the felling side, the valve rod 25 is pulled out from the valve hole 10, the ball valve 12 closes the valve hole 10 by the spring force of the spring 13, and the brake/fres pressure is transmitted from the master cylinder 45 to the brake 47. When the piston 22 moves further to the left, the volume of the output hydraulic pressure chamber 24 increases, so that the brake hydraulic pressure is reduced and the brake 47 is released.

In the above case, 1ill? Nl rW pressure side ball valve 3
2, the pressure in the human power fluid 1,000 chamber 28 is higher than the pressure in the output hydraulic pressure chamber 34, so the orifice 30 is opened (see Figure 2).The rear wheel 46 is locked by releasing the brake 47. When the controller 49 comes out of a state near or above, the controller 49 detects the state through the rotation sensor 48, cancels the anti-skid signal, returns the solenoid valve 37, and closes the output port door again (FIG. 3). ,
The pressure in the output hydraulic pressure chamber 34 becomes -H, and the balance of pressure acting on the piston 22 is disrupted, causing it to move to the right.

The movement 1 of the piston 22 results in an output l on the brake fluid pressure side.
Life II - Because the hydraulic pressure in chamber 24 is earth-like, brake 47+
As the brake fluid increases, the rear wheel 46 is again locked or close to locking, and as described above, the lock signal is output and the brake is released.

By repeating this action two or three times, the wheels are prevented from skidding.

[When Controlled Hydraulic Pressure Loss] (Fig. 1 7 Fig. 4) In the state shown in Fig. 1, due to failure of the hydraulic pump 51, etc., the control fil (I
If a failure occurs in the r & pressure system, the pressure in the input hydraulic pressure chamber 28 will be zero, so the spring force of the stopper pin 38 or its spring 4.1 will protrude from the spring 4. Therefore, the piston 22 can move to the left, and the valve hole 1 on the brake fluid pressure side
0 in the open state (hold at this time).

Therefore, although the anti-skid function is lost, the normal braking function is ensured, resulting in a so-called fail-safe.

To ensure the above-mentioned functionality, the stopper pin 38 engages with the piston 221 when the piston 22 is fully advanced, that is, when the ball valve 12 is fully open. Most preferably, the ball valve 12
If opening of the small pore 39 is ensured by a predetermined amount, it is acceptable to set the position of the small pore 39 so that it engages with the stopper pin 3B at a position where the piston 22 is slightly retracted.

(G) In the embodiment described in Other Embodiments, an orifice 301 and ball'/T'32 are provided, and when the solenoid valve 37 is opened, the human hydraulic pressure chamber 28 and the output P! , the piston 22 is moved to the left while maintaining a large pressure difference in the Kawamuro 4, but if it is possible to raise the orifice 30 and obtain the desired pressure difference,
There is no problem even if the ball valve ', 32 is omitted.

(Effects) As shown in the above, this invention provides a stopper with the control M1 fluid (which applies the required pressing force and is placed in the required position) so that it engages with the piston. A failure in the control 1 hydraulic system was detected on the night of the 2nd night, and the 1ift operation was quickly carried out.
This has the effect of safely losing the antilock function and ensuring the normal (11) movement function.

[Brief explanation of the drawing]

FIG. 1 is a sectional view, and FIGS. 2 to 4 are diagrams for explaining the order of production. 1... Actuator wood, 3... Human power port,
4... Output port, 6... Manpower port, -t... Output capo-1-18... Bore, 10... Valve hole, 11... Manpower hydraulic pressure chamber, 12... Ball valve, 19...Small diameter part, 2
C) ・Medium diameter part, 21...Large diameter part, 22...Piston, 24...Output S chamber, 25...Valve stem, 28
...Input liquid 11: chamber, 30...orifice, 32...
-Ball valve, 34...Output fluid chamber, 35-Balance splinter, 37...Solenoid valve, 38...Stotsunogu-pin patent applicant Sumitomo Electric Industries, Ltd. Sekido Agent Sickle 1) Interchange 2nd 3rd Figure 6 Figure 4

Claims (2)

[Claims] (1) Both pressure-receiving surfaces of the piston housed in the actuator body (brake fluid pressure and control fluid pressure are applied to these surfaces respectively, and the brake fluid pressure regulating valve that follows the piston is placed on the brake fluid pressure side, and the anti-brake fluid pressure control valve is placed on the control hydraulic pressure side). The anti-skid actuator is equipped with a solenoid valve that is activated by the skid controller, and opens the C solenoid valve in response to the anti-skid signal to reduce the control pressure 1 and return the piston.
Here, the wall surface of the control 1llI hydraulic pressure chamber (with 1 retractable stopper installed), the pressing force that urges the stopper in the protruding direction is set to be smaller than the control 1llll hydraulic pressure in normal conditions, and the piston The engagement part for the stopper is provided in the above, and the position of the stopper is adjusted to the state where the brake fluid adjustment valve is opened (hereinafter, the 1st part is engaged). The anti-skid actuator is characterized in that the engagement position is selected. (2) - A patent claim characterized in that the stopper is set at a position where the piston can engage the engaging portion in a state where the brake fluid pressure regulating valve is opened by a maximum of one position. The anti-skid actuator of QIj2, item 1, item 1.