JPH0125101Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in a deceleration sensing type hydraulic pressure control device for a vehicle brake system, and in particular to its air vent mechanism.

It has been well known that vehicle braking force needs to be reduced by a predetermined ratio on the rear wheels compared to the front wheels due to the difference in the pressing force of the front and rear wheels against the road surface during braking. It is also known that the pressing force changes in response to changes in the loading state of the vehicle.

Therefore, in response to such changes, various measures have been taken to prevent the occurrence of wheel lock by distributing brake force between the front and rear wheels as ideally as possible.
For example, by setting the hydraulic force and spring force between pistons facing the input and output hydraulic pressure chambers that have different hydraulic pressure receiving areas and the spring that applies spring force to these pistons, the rear wheel brake hydraulic pressure is reduced to a certain point. A proportioning type hydraulic pressure control valve is used to control the valve, and when the deceleration during vehicle braking reaches a certain value, communication with the sealing liquid chamber is cut off, and the valve is adjusted according to the sealed hydraulic pressure value. There is also provided an inertia valve which compresses the spring and varies the starting point of corner point pressure reduction control in accordance with the amplification of the spring force.

This type of hydraulic control device is difficult to achieve the ideal distribution of front and rear brake force because the brake force required to obtain a constant deceleration increases in proportion to the increase in vehicle load. This is designed to obtain approximate control characteristics.

By the way, in such devices, the fluid pressure state in the sealing fluid chamber, which is separated from the main brake fluid transmission system by the inertia valve, is an important factor that determines the characteristics for corner point pressure reduction control. From doing this,
For example, operations such as so-called air bleeding when assembling the device must be performed reliably and completely like other parts of the brake fluid system. Therefore, conventionally, an air bleeder facing the sealing fluid chamber has been provided separately from an air bleed device (hereinafter referred to as an air bleeder) for the main brake fluid transmission system.

However, this air venting operation has traditionally not been easy to perform. In other words, when venting air, hydraulic pressure is applied to the main brake fluid transmission system, and the air bleeder facing the sealing fluid chamber is opened to bleed air from the same chamber. In this case, when the air bleeder is opened, the seal is Because the liquid pressure in the liquid stop chamber disappears,
A rapid flow of fluid from the main brake fluid transmission system through the inertia valve to the sealing fluid chamber can occur, which can cause the inertia ball to abut against the valve seat.
Once the inertia ball comes into contact with the valve seat, the sealing state between the inertia ball and the valve seat continues due to hydraulic action, making it impossible to bleed out sufficient air from the sealing liquid chamber. It is.

To prevent this problem and completely bleed the sealing fluid chamber, gradually apply a very low fluid pressure over time to avoid the inertia ball hitting the valve seat due to the fluid flow. It is necessary to take measures such as venting air through the brake fluid or providing a bypass path to connect the main brake fluid transmission system and the sealing fluid chamber.

Therefore, the present applicant has proposed a means for mechanically locking the inertial ball in contact with the valve seat when air is vented from the sealing liquid chamber, for example, by manual operation from outside the valve body to prevent the assembly of the inertial ball and the valve seat. We have developed a mechanism that releases the state and permanently opens the liquid flow from the inertial ball storage part to the sealing liquid chamber, thereby solving the above-mentioned complication in air venting work. The present invention further improves this, and when the air bleeder is opened, a locking rod that locks the inertia ball against the valve seat without releasing the assembled relationship between the valve seat and the inertia ball is attached to the shaft inside the valve seat. Provided is a deceleration-sensing hydraulic pressure control device that protrudes from the core flow path toward the inertia ball, and when the air bleeder is closed, the locking rod automatically retracts to bring the inertia ball into contact with the valve seat. It is something to do.

The feature of the deceleration-sensing hydraulic pressure control device for vehicle brake systems of the present invention that achieves this purpose is that the brake fluid pressure transmitted from the master cylinder to the vehicle rear wheel brake system is adjusted to the sealing fluid pressure value in the sealing fluid chamber. a hydraulic pressure control valve that performs pressure reduction control based on a corner value determined accordingly, a valve seat that communicates between the brake fluid pressure transmission system and the sealing fluid chamber through an axial passage, and deceleration during vehicle braking. deceleration of a vehicle brake system, which is equipped with an inertia valve mechanism in which an inertia ball abuts the valve seat to seal a sealing fluid chamber communicating with a brake fluid pressure transmission system when In the sensing type hydraulic pressure control device, the sealing liquid chamber is provided with an air vent mechanism that communicates and shuts off the sealing liquid chamber with outside air by tightening the bleeder to close it and loosening it to open it. a locking rod that is provided so as to be able to protrude in the direction of the inertial ball through the flow path; and a locking rod that is engaged with the locking rod and is deformed when the bleeder is tightened to close it, and the deformation is restored when the bleeder is loosened and opened. A spring member is provided, and the locking rod projects from the flow path of the valve seat axis toward the inertial ball only when the deformation of the spring member is restored by loosening and opening the bleeder.

Embodiments of the present invention will be described below based on the drawings.

The embodiment shown in the drawings is a case where the present invention is applied to a deceleration sensing type hydraulic pressure control device for double piping, but it goes without saying that it may be used for a single system.

In Fig. 1, 1 and 2 are valve bodies, 3,
Reference numerals 4, 5, and 6 are stepped cylinders that house proportioning-operated hydraulic pressure control valves, and the opening of the largest diameter cylinder 6 (on the right side in the figure) faces the spring housing portion 7.

The hydraulic pressure control valve constitutes a known hydraulic pressure control mechanism for double piping, in which 8 is a cylindrical fail-safe piston, 9 is a balance cylinder, 10 is a back-up, 11 is a middle cylinder member, and 12 is a cylinder member. The middle cylinder 13 is a balance piston slidably fitted to the balance cylinder 9, one end of which is connected to the B system input liquid chamber b ₁
is inserted through it and faces the output liquid chamber _b2 , and the other end faces the A system output liquid chamber _a2 . Reference numeral 14 denotes a valve seat assembled into the inner cylinder portion of the fail-safe piston 8, which cooperates with a valve body portion formed at the head portion of the balance piston 13 to form a B-series valve portion. 1
5 is a hold spring, and 16 is a locking ring.

Reference numeral 17 denotes a control piston for the A system, one end of which is connected to the balance piston 13 within the A system output liquid chamber _a2 via a failsafe clip 18 so as to have a separation limit of a certain length, and the other end is connected to the middle cylinder 12. It is inserted through and faces the spring housing portion 7. Reference numeral 19 denotes a valve seat assembled in the cylinder 5, which cooperates with a valve body formed at the head of the control piston 17 to form an A-system valve section. 20 is a hold spring, 21 and 22 are spring seats, 23 is a piston cup, and 24 is a locking ring.

25 is the spring housing portion 7 of the control piston 17
It is a cap-shaped spring seat assembled to the other end protruding from the spring seat, and a control spring 28 is stretched between this spring seat and an adjustment piston 27 that is slidably fitted to an adjustment cylinder 26. An adjustment spring 29 is tensioned between the spring seat 25 and the valve body 1 and applies a spring force in a direction that opposes the spring force of the control spring 28.

The spring seat 30 attached to the adjustment piston 27 is provided so that its axial movement within the spring housing chamber 7 is restricted to a certain length or less, thereby limiting the compression limit of the control spring 28. is configured to have.

To briefly describe the operation of the hydraulic pressure control valve with the above configuration, hydraulic pressure is transmitted from the master cylinder to the A and B system input liquid chambers a ₁ and b ₁ by each piston, which is normally in the rest position shown in the figure. Then, this hydraulic pressure is transmitted to the output liquid chambers a ₂ and b ₂ through the A and B system valve parts, and then to the respective rear wheel brake devices. Based on the relationship between the size of the hydraulic pressure receiving area facing the input and output fluid chambers a ₁ and a ₂ of the control piston 17 and the biasing spring force of the control spring 28, the A system adjusts the output fluid from a constant brake fluid pressure value. The corner point pressure reduction control of the pressure P _a2 is started with respect to the input hydraulic pressure P _a1 , and along with this, the corner point pressure reduction control of the B system is passively generated. The corner value at this time is variably increased depending on the degree of compression of the control spring 28 by the adjustment piston 26, but the movement of the adjustment piston 26 is caused by the sealing liquid pressure P _c in the sealing liquid chamber C of the inertia valve to be described later. It will be determined.

The input liquid chambers a ₁ and b ₁ of the A and B systems are respectively communicated with the master cylinders of the respective systems in the same row, and the output liquid chambers a ₂ and
b ₂ are connected to the rear wheel brake devices of each system, so that the braking force on the rear wheel side can be reduced compared to the front wheel side.

Next, the inertial valve will be described. Reference numeral 31 denotes an inertial valve housing chamber, in which a cylindrical seat member 32 and a valve seat structure 35 including a valve seat 36 are positioned by fastening and fixing the valve bodies 1 and 2. Sheet member 3
The ball accommodating portion in 2 is communicated with the sealing liquid chamber C through the opening of the valve seat. Reference numeral 33 denotes a guide surface of an inertia ball 34 formed on the inner surface of the seat member 32, which forms an elevation angle θ with respect to the vehicle's progress as indicated by the arrow in the figure. At times, the inertia ball 34 is configured to sit on the valve seat 36 and seal the sealing liquid chamber C.

This sealing liquid chamber C is configured to face the end of the adjustment piston 27 within the adjustment cylinder 26.

Further, the circumferential gap formed between the inertial valve accommodating portion 31 and the outer periphery of the seat member 32 is located in the A system liquid draining chamber.
A fluid passage 37 is formed between the a ₂ and the rear wheel brake device via a port (not shown), and a fluid passage 37 is formed between the fluid passage 37 and the inertia ball accommodating portion in the cylinder of the seat member 32. Fluid passage openings 38 and 39 that communicate with each other are formed in pairs and separated from each other before and after the movement of the inertial ball 34.

With this configuration, the fluid pressure value in the sealing fluid chamber C is determined by the inertia ball 34 in the inertia valve being seated against the valve seat 36, thereby controlling the corner point pressure reduction to the rear wheel brake device. The basic working relationship, in which the hydraulic pressure is also determined, is the same as the existing one, but a pair of liquid passage openings 38,
39, the liquid flow is conducted through the liquid passage opening 38 and then 39 into the inertial ball housing. Although there is actually an extremely small time difference between before and after such transmission, this has a good effect on the movement of the inertia ball 34 in correlation with the sudden slowing down of the brake operation, and for example, when the brake fluid pressure is relatively low. During normal braking, which starts slowly, the effects on the inertia ball 34 due to the liquid flow flowing in from the pair of liquid passage openings 38 and 39 cancel each other out, thereby preventing the risk of malfunction due to factors other than inertial force. However, when the brake fluid pressure rises rapidly, such as during sudden braking, the influence of the inflowing fluid flow from the fluid passage opening 38 located on the master cylinder side in the system becomes large, and this fluid flow becomes Under the influence, the movement tendency of the inertial ball 34 to come into contact with the valve seat 36 is amplified, and the valve seat 36 is amplified by normal inertial movement alone.
This has the effect that it is possible to prevent the problem that the closing of the opening of the valve is delayed and abnormally high hydraulic pressure is sealed.

The feature of the present invention lies in the configuration of the air venting device for the sealing liquid chamber C which is particularly suitable for the hydraulic pressure control device having the configuration shown in the figure. To explain the configuration of this example for this purpose, the valve seat component 35 is A stepped cylindrical plug 40 is fixed by fastening the valve bodies 1 and 2 through the seat member 32, and a shaft body and a disc spring-like spring member, which will be described later, are installed at predetermined positions in the stepped inner cylindrical portion of this plug 40. As shown in the figure, the valve seat 36 is fixed opposite to the inertia ball 34 in the inertia valve accommodating part.

The seal holder 41 has an axial flow path 42 formed in its axial center for communicating the liquid chamber on the inertial ball 34 side and the sealing liquid chamber, and also connects the sealing liquid chamber C of this axial flow path 42 with the liquid chamber on the inertial ball 34 side. The opening is provided with a stepped large diameter, and a spring member 43 as described below is engaged with this large diameter opening.

As shown in FIGS. 2A and 2B, this spring member 43 has a plurality of tongues 43b (three in this example) protruding radially inward from a ring portion 43a having an annular shape. In the natural state, the ring portion 43a extends obliquely to one surface side (one side in the axial direction), and the intermediate portion of the inclination of each of the inclined tongues 43b engages with the large diameter opening edge of the seal holder 41. The ring portion 43a is formed and arranged so as to float above the end surface of the seal holder 41 in its natural state.

44 is a ring portion 43a of this spring member 43 which is pressed against the seal holder 41 by the shaft body 45.
It is a cup-shaped member that is pressed against the end surface of the brake, and the cup-shaped portion has an opening partially formed through which brake fluid passes.

The shaft body 45 has a through-axis flow path for air venting in its axial center, and has a large-diameter portion that fluid-tightly slides into a small-diameter cylinder 46 formed in the valve body 2 at one end, and a large-diameter portion at the other end. It is formed to form a liquid flow path with the small-diameter cylinder 46 and has a small-diameter portion that engages with the cup-shaped member 44, and is formed concentrically with the small-diameter cylinder 46 of the valve body 2. When the air bleeder 49 is screwed into the threaded portion 50 , the screwing force presses the cup-shaped member 44 and releases the spring member 43 .
The ring portion of the seal holder 41 is pressed against the end surface of the seal holder 41. By screwing in the air bleeder 49, the tip protrusion of the air bleeder 49 tightly engages with the opening of the axial flow path of the shaft body 45, cutting off communication between the sealing liquid chamber C and the outside air, and the other end. When the screw is loosened, the engagement with the shaft body 45 is released and the sealing liquid chamber C is configured to communicate with the outside air.

Therefore, when the air bleeder 49 is screwed in to close the cap, the ring portion 43a of the spring member 43 is pressed against the end surface of the seal holder 41, and each tongue piece 43 is pressed against the end surface of the seal holder 41.
b is elastically deformed and deformed in a direction that makes the inclination with respect to the ring portion 43a gentle (a direction that goes out from the large diameter opening of the seal holder 41 to the outside of the opening), and when the air bleeder 49 is opened, the spring member 43 returns to its natural state. Then, each tongue piece 43b returns to its original state so as to enter inside the large diameter opening of the seal holder 41.

Reference numeral 51 denotes a locking rod that is assembled to be held by the tip of each tongue of the spring member 43, and the tip of the locking rod is inserted through the axial flow path 42 of the seal holder 41 and is connected to the valve seat 3.
It is formed and arranged so that it can protrude from the opening of 6 toward the inertial ball 34 side. And this locking rod 51
The tongue piece 43b of the spring member moves as it deforms and restores itself as the air bleeder 49 is opened and closed, and when the air bleeder 49 is closed, it enters the axial flow path 42 of the seal holder 41 and causes the inertia ball 34 and valve seat 36 to move. Although it does not interfere with the fitting, when the air bleeder is opened, it protrudes from the opening of the valve seat 36 and becomes a hindrance to the fitting of the inertial ball 34 with the valve seat 36.

According to such a configuration, after the device is assembled, the bleeder 45 is loosened from the screw hole 44 in order to vent air from the sealing fluid chamber C, and the pressing force of the seal holder 41 is released, and the main brake fluid transmission is performed. By applying hydraulic pressure to the system (that is, the system passing through the inertia ball 34) and performing a predetermined air removal operation from the air bleeder 45, air removal can be achieved satisfactorily. That is, in this case, the liquid pressure in the sealing liquid chamber C disappears, and the sealing liquid chamber C is removed from the side where the inertia ball 34 is located.
A large liquid flow to the side occurs, resulting in inertia ball 3
4 is moved together, in this case the spring member 43 returns to its natural state and the locking rod 51
protrudes from the valve seat 36 and locks the inertia ball 34 in contact with the valve seat 36.
Since a liquid-tight seal between the valve seat 36 and the valve seat 36 does not occur, sufficient liquid replenishment to the sealing liquid chamber C can be achieved.

It should be noted that the present invention is not particularly limited to the embodiments described above, and can of course be applied to, for example, a hydraulic pressure control device for one system.

As described above, the deceleration-sensing hydraulic pressure control device for vehicle brake systems according to the present invention has a simple configuration and relatively easy work to bleed air from the sealing fluid chamber in this type of device. It has the advantage that it can be carried out in
Its practical benefits are enormous.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a hydraulic pressure control device showing an embodiment of the present invention, and FIGS. 2A and 2B are individual views of the spring member 43. 1, 2... Valve body, 3, 4, 5, 6...
Stepped cylinder, 7... Spring housing section, 8...
Fail-safe piston, 9... Balance cylinder, 10... Back up, 11... Middle cylinder member, 12... Middle cylinder, 13... Balance piston, 14... Valve seat, 15... Hold spring, 16... Locking ring, 17... Control piston, 18... Fail-safe clip,
19...Valve seat, 20...Hold spring, 21, 22...Spring seat, 23...Piston cup, 24...Lock ring, 25...Spring seat, 26...Adjustment cylinder, 27...Adjustment piston , 28... control spring, 29...
Adjustment spring, 30... Spring seat, 31...
...Inertial valve housing section, 32... Seat member, 33...
Guide surface, 34... Inertia ball, 35... Valve seat structure, 36... Valve seat, 37... Liquid passage, 38...
Liquid passage opening, 39...Liquid passage opening, 40...Plug,
41... Seal holder, 42... Axial flow path, 43...
...Spring member, 43a...Ring part, 43b...
Tongue piece, 44...Cup-shaped member, 45...Shaft body, 4
6... Small diameter cylinder, 47... Axial flow path, 48...
Liquid flow path, 49... air bleeder, 50... screw hole, 51... locking rod.

Claims (1)

[Scope of Claim for Utility Model Registration] A hydraulic pressure control valve that reduces the brake fluid pressure transmitted from the master cylinder to the rear wheel brake system of the vehicle using a corner value determined according to the sealing fluid pressure value in the sealing fluid chamber. and a valve seat that communicates between the brake fluid pressure transmission system and the sealing fluid chamber through a passage in the shaft center, and an inertia ball that connects to the valve seat when the deceleration during vehicle braking exceeds a certain value. In a deceleration-sensing hydraulic pressure control device for a vehicle brake system, the device includes an inertia valve mechanism that seals a sealing fluid chamber that communicates with a brake fluid pressure transmission system, wherein the sealing fluid chamber includes: An air bleed mechanism is provided that connects and blocks the sealing liquid chamber with outside air by tightening the bleeder to close it and loosening it to open it, and is provided so as to be able to protrude in the direction of the inertial ball through the axial center flow path of the valve seat. A locking rod and a spring member that is engaged with the locking rod and is deformed when the bleeder is tightened and closed, and the deformation is restored when the bleeder is loosened and opened, are provided. A deceleration sensing type hydraulic pressure control device for a vehicle brake system, characterized in that the locking rod projects from the flow path of the valve seat axis toward the inertial ball only when the deformation is restored.