JPH0243666B2 - GENSOKUDOKANCHIGATASEIDOEKIATSUSEIGYOSOCHI - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement in a deceleration sensing type brake hydraulic pressure control device.

(Prior Art) Various deceleration-sensing brake fluid pressure control devices have been proposed in the past that detect changes in the vehicle's live load as changes in deceleration during braking and control the brake fluid pressure ratio of the rear wheels. There is.

For example, Japanese Patent Application Laid-Open No. 56-34558 (hereinafter referred to as Prior Art 1) proposes a device that detects deceleration using an inertial ball and a gradient. There is no linear relationship between the speeds, (2) the behavior of the ball is unstable due to vibrations from the road surface, (3) the brake fluid flow has a large effect on the ball, and (4) the coaxiality of the ball and seat is poor. In addition to problems such as performance being influenced by (5) the ball rolling on a slope, there was a problem that the braking force of the rear wheels was noticeably insufficient when heavily loaded due to (1).

Therefore, in order to solve the above problem (1), in Japanese Patent Publication No. 11613/1982 and Japanese Patent Publication No. 38424/1984 (hereinafter referred to as Prior Art 2), an inertial ball is biased with a spring, and the A device has been proposed that controls the deceleration at the start of ball movement by continuously varying the load, but in addition to problems (3) and (4) above, (6) a separate component is required to control the spring. (7) There were problems such as friction with the spring when the ball rolled.

(Object of the Invention) The present invention has been made in view of the above-mentioned conventional problems, and basically, by adopting a sleeve-shaped inertial sensor instead of an inertial ball, various problems caused by using a ball can be solved. The purpose is to solve the following problems all at once.

(Structure of the Invention) Therefore, the deceleration sensing type brake fluid pressure control device according to the present invention has a first chamber in the front part of the plunger fitting hole in the longitudinal direction of the vehicle, a second chamber in the middle part, and a second chamber in the rear part. Third
a first branch passageway which is provided with a chamber and extends from a hydraulic inlet communicating with the master cylinder to a second chamber;
A second branch passage leading to the third chamber is provided, a third branch passage leading to the first chamber from a hydraulic pressure outlet communicating with the rear wheel cylinder, and a fourth branch passage leading to the third chamber, A plunger is fitted into the plunger fitting hole so as to be movable back and forth, and is biased forward by a main spring. is formed, and is provided with an internal passage that communicates the first chamber and the second chamber, and a valve that opens the internal passage when it comes into contact with the front wall of the first chamber, and the third chamber is provided with:
A sleeve-shaped inertial sensor is fitted so as to be movable back and forth, and is biased backward by a sensor spring. When the inertial sensor moves forward by a predetermined amount, the fourth branch passage is closed, and the plunger is moved backward. The sensor spring is configured to be compressed when the sensor spring moves a predetermined amount.

Therefore, until near the turning point when the load is light, the plunger is moved forward by the main spring and the valve opens the internal passage of the plunger, so the working hydraulic pressure of the master cylinder is changed from the hydraulic inlet to the first branch passage to the first branch passage. 2nd room →
Internal passage → first chamber → third branch passage → first flow passage from hydraulic pressure outlet, and from hydraulic inlet to second branch passage → third
It acts on the rear wheel cylinder through the chamber → the fourth branch passage → the second flow passage leading to the hydraulic pressure outlet.

In the case of a light load, the hydraulic pressure near the turning point when the load is light causes a deceleration greater than the biasing force of the sensor spring, causing the inertial sensor to move forward and close the fourth branch passage. There is only a flow path, and the plunger functions as a proportional pressure reducing valve (PCV). On the other hand, in the case of medium or heavy loads, when the hydraulic pressure is near the turning point when the load is light, deceleration greater than the biasing force of the sensor spring does not occur, so the second flow path remains open. When the turning point in the loading period is exceeded, the second flow path remains open and the plunger is moved backward by the hydraulic pressure, compressing the sensor spring and
Since the valve closes the internal passage of the plunger, only the second flow path remains open, and thereafter the second flow path remains open until a deceleration greater than the biasing force of the compressed sensor spring occurs.

(Effects of the Invention) According to the present invention, since a sleeve-shaped inertial sensor is used as the inertial sensor, problems (1) to (7) caused by the conventional inertial ball described above can be solved at once. be able to.

In addition, in Prior Art 1, when the ball sensor is activated, liquid pressure is sealed in the blind chamber, and then the proportional pressure reducing valve is activated, resulting in a breaking point, but in the present invention, after the inertial sensor is activated, Since a breaking point occurs immediately, responsiveness is improved.

In addition, compared to conventional technology 2 in which the proportional pressure reducing valve (PCV) section and the inertial sensor are simply connected in parallel, the present invention dramatically increases the turning point during heavy stacking, and effectively reduces the operating pressure of the master cylinder. It can be transmitted to the rear wheel cylinder to increase braking force.

Furthermore, even in the event of overloading or failure of the front system, the turning point does not occur until the necessary deceleration occurs in the vehicle, so there is no need to add a separate safety device in case of failure.

(Embodiments) Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIGS. 1 and 2, a cover 2 is integrally connected to the rear part of a body 1 via a seal ring 3, and a plunger fitting hole 4 in the longitudinal direction of the vehicle is formed in the body 1. ing.

The front end of the plunger fitting hole 4 is closed by a plug 5, and the rear end extends into the cover 2 by a cylindrical portion 1a projecting from the rear surface of the body 1.

A first chamber 7 is provided in the front part of the plunger fitting hole 4, and a first chamber 7 is provided in the middle part of the plunger fitting hole 4. There are 2 rooms 8,
A third chamber 9 including a cavity inside the cover 2 is provided at the rear, and an air chamber 10 partitioned between the second chamber 8 and the third chamber 9 by the seal ring 12 and the seal cup 25 is provided. It is provided.

A hydraulic inlet 14 communicating with a master cylinder (not shown) is provided on the side of the body 1 (see FIG. 2), and a first branch passage 15 leading from the hydraulic inlet 14 to the second chamber 8 and a second branch passage 16 leading to the third chamber 9 are formed.

Further, a hydraulic pressure outlet 17 communicating with a rear wheel cylinder (not shown) is provided in the upper part of the body 1, and a third branch passage 18 leading from the hydraulic pressure outlet 17 to the first chamber 7 and a third chamber 16 Fourth branch passage 19 leading to
is formed.

The fourth branch passage 19 opens at the rear surface of the body 1, and a sheet 20 is fitted into the opening.

The plunger 11 is urged forward by a main spring 13 compressed in the air chamber 10.

The plunger 11 has a large diameter pressure receiving surface portion 11a formed in the second chamber 8 and a small diameter pressure receiving surface portion 11b formed in the third chamber 9.

Further, the plunger 11 is formed with an internal passage 21 that communicates the first chamber 7 and the second chamber 8, and the front part of the internal passage 21 is biased forward by a spring 22, and the valve seat 23 is biased forward. A poppet valve 24 is provided which closes the internal passageway 21 when seated;
The poppet valve 24 is configured to open the internal passage 21 when the plunger 11 moves forward and the tip 24a comes into contact with the front wall 7a of the first chamber 7 and retreats and leaves the valve seat 23.

On the other hand, in the third chamber 9, a sleeve-shaped inertial sensor 26 is fitted to the cylindrical portion 1a of the body 1 via ball bearings 31, . . . , 31 so as to be movable back and forth.

The inertial sensor 26 is compressed between a spring holder 28 that is held against a seal retainer 27 fixed in the plunger fitting hole 4 of the cylindrical portion 1a, and a spring seat 29 that closes the rear end of the inertial sensor 26. The rear end portion 26a is biased rearward by the sensor spring 30, and the rear end portion 26a is in contact with the rear wall 9a of the third chamber 9.

With the rear end 26a of the inertial sensor 26 in contact with the rear wall 9a of the third chamber 9, the front end 26b of the inertial sensor 26 and the seat 20 of the fourth branch passage 19
A gap t ₁ is formed between the inertial sensor 2 and the inertial sensor 2.
6 moves forward by a gap _t1 , the inertial sensor 26 closes the fourth branch passage 19.

The plunger 11 has a rear wall 7b of the first chamber 7.
A shoulder portion 11c is provided which separates a gap t ₂ between the
There is a gap t ₃ between the third chamber 9 and the spring holder 28.
A shoulder portion 11d is provided to separate the two, and the gap is set to t ₂ > t ₃ so that the plunger 11 moves backward through the gap t _{3 .}
When the sensor spring 30 is moved by the same amount, the plunger 11 compresses the sensor spring 30 via the spring holder 28.

The operation of the brake hydraulic pressure control device configured as described above will be explained with reference to the flowchart in FIG. 3 and the graph showing changes in hydraulic pressure in FIG. 4.

When the hydraulic pressure is from 0 to around the turning point Pke when the load is light (the state shown in FIG. 1), the plunger 11 is moved forward by the main spring 13, and the tip 24a touches the front wall 7a of the first chamber 7. Poppet valve 2
4 is retracted and separated from the valve seat 23, and the internal passage 21 of the plunger 11 is opened.

Therefore, the working hydraulic pressure of the master cylinder is transferred from the hydraulic inlet 14 to the first branch passage 15 → second chamber 8 → internal passage 21 → first chamber 7 → third branch passage 18 → hydraulic outlet 17. Flow path a and a second line from the hydraulic inlet 14
It acts on the rear wheel cylinder through the branch passage 16 → third chamber 9 → fourth branch passage 19 → second flow passage b leading to the hydraulic pressure outlet 17.

In the case of a light load, when a deceleration greater than the biasing force G1 of the sensor spring 30 occurs due to the hydraulic pressure near the turning point Pke when the load is light, and the inertial sensor 26 moves forward, the front end 26b of the inertial sensor 26 Since the fourth branch passage 19 is closed, the second passage b is closed and only the first passage a remains.

Then, the plunger 11 has a gap t ₄ (see Figure 1).
It moves back and forth within the range of , acting as a proportional pressure reducing valve (PCV).

In the case of medium or heavy loads, the biasing force of the sensor spring 30 (G1) at the hydraulic pressure near the turning point Pke during light loads.
Since the above deceleration does not occur, the second passage b remains open, but when the turning point Pke at the time of light loading is exceeded, the second passage b remains open and the plunger 1
The plunger 11 is moved backward against the biasing force of the main spring 13 by the working fluid acting on the large diameter pressure receiving surface portion 11a of the sensor spring 30.
is compressed, and at the same time the poppet valve 24 moves forward,
It seats on the valve seat 23 and closes the internal passage 21 of the plunger 11.

Therefore, the working hydraulic pressure of the master cylinder comes to act on the rear wheel cylinder through the second flow path b.

Then, at the hydraulic pressure near the turning point Pkg during intermediate loading or the turning point Pkf during heavy loading, a deceleration greater than the biasing force (G2) of the compressed sensor spring 30 occurs.
When the inertial sensor 26 moves forward, the fourth branch passage 19 is closed by the front end 26b of the inertial sensor 26, so the second flow passage b is also closed.

[Brief explanation of drawings]

Fig. 1 is a longitudinal cross-sectional view of a deceleration sensing type brake hydraulic pressure control device according to the present invention, Fig. 2 is a cross-sectional plan view of the main part of Fig. 1, Fig. 3 is an operation flow chart, and Fig. 4 is a hydraulic pressure control device. It is a graph showing changes. 1... Body, 2... Cover, 4... Plunger fitting hole, 7... First chamber, 8... Second chamber, 9...
Third chamber, 11... Plunger, 11a... Large diameter pressure receiving surface section, 11b... Small diameter pressure receiving surface section, 13... Main spring, 14... Hydraulic pressure inlet, 15... First
Branch passage, 16... Second branch passage, 17... Hydraulic pressure outlet, 18... Third branch passage, 19... Fourth branch passage, 21... Internal passage, 24... Poppet valve, 26... Inertial sensor , 30...sensor spring.

Claims (1)

[Claims] 1. A first chamber is provided at the front of the plunger fitting hole in the longitudinal direction of the vehicle, a second chamber is provided at the middle, and a third chamber is provided at the rear, and a hydraulic inlet communicating with the master cylinder. From, the second
A first branch passage leading to the chamber and a second branch passage leading to the third chamber are provided, and a third branch passage leading to the first chamber and a third branch passage leading to the third chamber from the hydraulic pressure outlet communicating with the rear wheel cylinder. A fourth branch passage is provided, a plunger is fitted into the plunger fitting hole so as to be movable back and forth, and is urged forward by a main spring, and the plunger has a large diameter pressure receiving surface in the second chamber. and a small-diameter pressure-receiving surface portion in the third chamber, and an internal passage communicating the first and second chambers;
A valve that opens an internal passage when it comes into contact with the front wall of the chamber is provided, and a sleeve-shaped inertial sensor is fitted into the third chamber so as to be movable back and forth, and is biased backward by a sensor spring. When the inertial sensor moves forward a predetermined amount,
A deceleration sensing type brake hydraulic pressure control device, characterized in that the fourth branch passage is closed and the plunger compresses a sensor spring when moved rearward by a predetermined amount.