JPS5831726Y2 - Braking hydraulic control device - Google Patents

Description

[Detailed Description of the Invention] The present invention provides a brake hydraulic control device installed in a vehicle, in particular, a brake hydraulic control device having an inlet communicating with a master cylinder and an outlet communicating with a wheel cylinder, and communicating with the inlet inside the brake hydraulic control device. a stepped inner hole having a small diameter inner hole and a large diameter inner hole communicating with the outlet; and a first oil chamber provided in parallel with the stepped inner hole and communicating with the small diameter inner hole and the large diameter inner hole. a housing main body, the large diameter portion of which is slidably inserted into the large diameter inner hole of the stepped inner hole to form a second oil chamber that communicates with the first oil chamber; a differential piston that is slidably inserted into a small diameter inner hole of the stepped inner hole to form a third oil chamber that communicates with the first oil chamber; A brake comprising: a spring biasing the first oil chamber; and a cutoff valve having an inertia valve body housed in the first oil chamber and blocking communication between the first oil chamber and the second oil chamber by its inertia force. This relates to the improvement of hydraulic control devices, and its purpose is to create a device that can bring the ratio of brake hydraulic pressure applied to the front and rear wheels as close as possible to the ideal distribution ratio that changes depending on the amount of cargo when braking the vehicle. Our goal is to provide the following.

An example of this will be explained below with reference to the drawings.
In the figure, reference numeral 10 indicates a known tandem-type master cylinder operated by the depression of a brake pedal 13, reference numeral 14 indicates a rear wheel cylinder, and reference numeral 15 indicates a front oil chamber 11 of the master cylinder 10.
The front wheel cylinder is shown directly connected to the rear oil chamber 12 of the master cylinder 10 by a conduit 16, and the rear oil chamber 12 of the master cylinder 10 and the rear wheel cylinder 14 are equipped with a deceleration-sensing brake hydraulic pressure control device according to the present invention. 20 is interposed.

The brake hydraulic control device 20 includes a housing body 30 fixed to a sprung member (not shown) at a predetermined angle of inclination;
Large diameter piston 41 incorporated into this housing body 30
．． It is equipped with a small diameter piston 42 and an inertia ball 46.

The housing body 30 includes a rear housing 30A having an inlet 31 connected to the rear oil chamber 12 of the master cylinder 10 by a conduit 17, and a front housing 30 having an outlet 32 connected to the rear wheel cylinder 14 by a conduit 18. B, inside thereof, there is a stepped inner hole 33 having a small diameter inner hole where the inlet 31 opens, a large diameter inner hole where the outlet 32 opens, and an inner hole that accommodates the coil spring 43; A communication path 3 is provided in the small diameter inner hole of the attached inner hole 33.
5 and a second communication path 3 to the large diameter inner hole.
A first oil chamber R1 communicating through the stepped inner hole 33 is provided in parallel with the stepped inner hole 33.

Moreover, inside this housing main body 30, a first
An air vent passage 37 is provided that opens in the earthen wall of the oil chamber R0 and opens into the second communication passage 36 at the other end.

The large-diameter piston 41 is fitted into the large-diameter inner hole of the stepped inner hole 33 via seal members 51 and 52 so as to be able to slide in the axial direction, and the outflow port 32 is directly opened in the large-diameter inner hole. At the same time, the first oil chamber R1 communicates with the second oil chamber R1 through the second communication passage 36.
An oil chamber R2 is formed.

The small diameter piston 42 is a stepped piston and has a stepped inner hole 33.
The oil chamber R1 is fitted into the small diameter inner hole through a seal member 53 so as to be slidable in the axial direction, and the inlet 31 opens directly into the small diameter inner hole, and the first oil chamber R1 communicates with the small diameter inner hole through the communication path 35. A third oil chamber R3 is formed.

Further, this small diameter piston 42 is in contact with the right end of the large diameter piston 41 at its left small diameter portion.

The compression coil spring 43 is assembled into the inner hole with a predetermined preload applied thereto, and is detachable from the right end of the large-diameter piston 41 via an annular retainer 44 having a required outer diameter at its left end. the rear housing 3 at its right end.
Engaged to 0A.

The inertia ball 46 is accommodated in the first oil chamber R1 so as to be able to move forward, and is connected to the first oil chamber R1 by an annular valve seat 45 interposed between the first oil chamber R1 and the second communication passage 36. It constitutes a cutoff valve that opens and closes communication between the second communication passages 36.

The inertia ball 46 is supported by a support plate 47 having an orifice 47a fixed to the rear housing 30A side, and when the inertia force (deceleration) acting thereon exceeds a predetermined value, it rolls forward. and seats on the valve seat 45.

However, in this embodiment, the first oil chamber R1 is located at one end.
A bypass passage 38 is provided in the front housing 30B, which communicates with the large diameter bore of the stepped bore 33 at the other end.

The bypass passage 38 includes an annular groove 38 a provided in a large diameter inner hole located between both seal members 51 and 52 when the large diameter piston 41 is not in operation, and an annular groove 38 a that opens into the annular groove 38 a at one end and opens at the other end. The communication hole 38b opens into the first oil chamber R1, and is closed by the peripheral wall of the piston 41 and both seal members 51 and 52 when the large-diameter piston 41 is not in operation, and prevents the large-diameter piston 41 from sliding to the right in the figure. The seal member 5
1 slides beyond the left end of the annular groove 38a,
The first oil chamber R1 and the second oil chamber R2 are connected to the valve seat 45 and the ball 46.
Bypassing the shutoff valve consisting of the

Next, the operation of this embodiment will be explained with reference to FIGS. 1 to 4.

If the brake pedal 13 is depressed when the vehicle is empty,
The oil pressure in both oil chambers 11 and 12 of the master cylinder 10 increases, and the oil pressure in the front oil chamber 11 is directly applied to the front wheel cylinder 15 through the conduit 16, and the oil pressure in the rear oil chamber 12 is applied to the front wheel cylinder 15 through the conduit 16. 17 to the inlet 31 of the control device 20.

Master cylinder oil pressure Pm applied to this inlet 31
3rd oil chamber R3 continuous passage 35 - 1st oil chamber R1 - valve seat 45
The oil is supplied to the second oil chamber R2 through the valve hole and the second communication passage 36, and is further supplied to the rear wheel cylinder 14 through the outlet 32 and the conduit 18.

When master cylinder oil pressure is applied to each wheel cylinder 14, 15 in this manner, the vehicle is braked in accordance with the oil pressure Pm.

During this braking, the small diameter piston 42 is pushed leftward by the hydraulic pressure Pm applied in the third oil chamber R3, and the large diameter piston 41 is pushed rightward by the hydraulic pressure Pm applied in the second oil chamber R2. Due to the difference in the pressure receiving areas, the large diameter piston 41 and the small diameter piston 42 slide to the right against the elastic force of the spring 43.

In this way, when the master cylinder oil pressure Pm becomes P1 and the deceleration acting on the inertia ball 46 reaches a predetermined value, the ball 46 rolls forward and seats on the valve seat 45, and the first oil chamber R
Communication between the first and second communication paths 36 is cut off.

(See point A in FIG. 4) Also, at this time, the large diameter piston 41 has only slightly slid to the right as shown in FIG.
It is closed by the peripheral wall of and both seal members 51 and 52.

Therefore, when the master cylinder oil pressure Pm increases and the oil pressure in the third oil chamber R3 increases, both pistons 41.4
2 is pushed to the left, and the oil pressure in the second oil chamber R2 (rear wheel cylinder oil pressure Pw) rises as shown by line AB in FIG.

As a result, the oil pressure applied to both wheel cylinders 14, 15 becomes a value that approximates the ideal distribution line in the empty vehicle state shown by the dashed line in FIG.

By the way, when the vehicle is braked in the loaded state, the weight of the vehicle increases compared to the empty state, so even if the master cylinder oil pressure Pm becomes pl, the vehicle (A, decrease mum< If the predetermined φ value &,q, then no.

Therefore, at the 2nd tm, the hydraulic pressure Pm becomes 3% lower than the 2nd communication drop 1. ．． ．． ．． H:1. ．．
Shite?・1st series C, attached J large diameter piston 41 is ``9
It moves further to the right while keeping up with the situation.

Thus, when the master cylinder oil pressure Pr becomes P2, y"H", 17e1m material 51 is ring tm, '38',
:',"h%"'M.

Beyond the end, the second oil chamber R2 is connected to the annular groove 38a and the communication hole "j8".
It communicates with the first oil chamber R1 through □b.

As a result, when the master cylinder oil pressure Pm rises thereafter, the master cylinder oil pressure Pm bypasses the cutoff valve regardless of whether the ball 46 is seated on the valve seat, and the communication hole 38b,
It is provided to the second oil chamber R2 through the annular groove 38a.

As a result, the oil pressure applied to both wheel cylinders 14, 15 becomes the same, which approximates the ideal distribution line in the loaded state shown by the two-dot chain line in FIG.

At this time, the large-diameter piston 41 slides to the right as shown in FIG. 3 in response to the master cylinder oil pressure Pm applied to m2 narrow*□.

The master cylinder oil pressure indicated by P3 in FIG. 4 is a value at which the reball 46 is seated on the valve seat 45 when the deceleration of the vehicle is at a predetermined value in a loaded state.

In summary, in the present invention, as exemplified in the above embodiment, the bypass passage 38, which communicates with the first oil chamber R1 at one end and the large diameter inner hole at the other end, is connected to the housing 30B.
(housing main body), when the large diameter piston 41 (differential piston) is not in operation, the bypass passage 38 is closed by the peripheral wall of the differential piston, and the differential screws and screws are inserted into the large diameter of the bypass conduit 38. Slide beyond the opening on the hole side: ,h
2 is located in the first oil chamber R1 and the second oil chamber'.
The feature is that the shutoff valve consisting of the valve seat 46 and the valve seat 45 is connected in two-way communication (1, □). The ratio of the braking oil pressure applied to the rear wheels can be brought closer to the ideal distribution ratio.

[Brief explanation of drawings]

'□゛1 Fig. 1 is a brake system diagram including the brake hydraulic control device according to the present invention, Figs. 2 and 3 are operation explanatory diagrams, and Fig. 4
The figure is a graph showing a brake hydraulic pressure distribution line and an ideal distribution line obtained by the device according to the present invention. Explanation of symbols 10...Master cylinder, 14
...Rear wheel cylinder, 20...
- Braking hydraulic control device, 30...Housing body, 31...Inflow port, 32...□Outflow port, 3j! ...□Stepped inner hole, 38...Bypass passage, 41゜42...Large diameter, small diameter piston (differential piston), 43...Spring, 45
... Valve seat, 46... Ball (valve body),
R1...First oil chamber, R2...Second oil chamber, R3...Third oil chamber.

Claims (1)

[Scope of utility model registration request] a stepped inner hole having an inlet communicating with the master cylinder and an outlet communicating with the wheel cylinder, and having inside thereof a small diameter inner hole communicating with the inlet and a large diameter inner hole communicating with the outlet; A housing main body including a first oil chamber provided in parallel with the stepped inner hole and communicating with the small diameter inner hole and the large diameter inner hole, and a first oil chamber provided in the large diameter inner hole of the stepped inner hole. The diameter portion is slidably inserted to form a second oil chamber communicating with the first oil chamber, and the small diameter portion is slidably inserted into the small diameter inner hole of the stepped inner hole to form the first oil chamber. a differential piston forming a third oil chamber communicating with the oil chamber; a spring biasing the differential piston toward the second oil chamber; A brake hydraulic pressure control device comprising a cutoff valve having an inertial valve body that cuts off communication between a first oil chamber and a second oil chamber, one end of which communicates with the first oil chamber and the other end of which connects the first oil chamber with the first oil chamber. A bypass passage communicating with the inner diameter hole is provided in the housing body, and when the differential piston is not in operation, the bypass passage is closed by the peripheral wall of the differential piston, and the differential piston is inserted into the large diameter of the bypass passage. A braking hydraulic control device characterized in that when sliding beyond the hole side opening, the first oil chamber and the second oil chamber bypass the cutoff valve and communicate with each other.