JPH049246Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a brake pressure holding device, and in particular to an improvement of the device that automatically maintains the braking pressure even when the brake pedal is released when the vehicle is stopped. Regarding.

[Prior Art] In general, a braking pressure holding device for an automobile is designed to maintain the braking pressure obtained by depressing the brake pedal to stop the vehicle even when the brake pedal is released. It is said to be an effective means of preventing self-propulsion when the vehicle is stopped while in the drive range. This type of brake pressure holding device is interposed in the oil path leading from the master cylinder to the brake, maintains the brake pressure by blocking this oil path, and switches to the blocked state in response to a signal such as a vehicle start operation. It is starting to be released.

FIG. 2 shows a conventional braking pressure holding device. This braking pressure holding device includes a valve seat 3 and a ball valve body 4 at the tip of a plug 2 inserted into a housing 1.
The plug 2 has a valve body support member consisting of a spring 6 and a valve opening rod 7 built into a bored hole 5 that opens toward the ball valve body 4 side. The housing 1 is provided with an inlet port 8 that opens on the outer circumference side of the tip end of the plug 2, and an outlet port 10 that opens facing the branch hole 9 that communicates with the bore hole 5 of the plug 2 and opens on the outer circumference of the plug. The oil passage from 8 to the outlet port 10 via the bored hole 5 and the branch hole 9 is kept open by the action of the valve body support member, thereby securing the brake line from the master cylinder to the brake. There is. On the other hand, a push rod 12 driven by a solenoid 11 is disposed in the housing 1 at a symmetrical position with the valve opening rod 7 and the ball valve body 4 in between, and
By pushing the push rod 12 in response to a vehicle stop signal, the ball valve body 4 is pressed against the valve seat 3, thereby blocking the oil passage and maintaining braking pressure.

By the way, in this type of solenoid 11, it is necessary to maintain the valve seat 3 at a predetermined hardness, and the plug 2
From the viewpoint of assembling the spring 6 and the valve opening rod 7 into the bore hole 5, the plug 2 and the valve seat 3 are constructed as separate structures, and the two are integrated by press-fitting. In addition, in order to prevent a short circuit between the inlet port 8 and the outlet port 10 and to prevent internal hydraulic pressure leakage, a circumferential groove is formed in the land portion of the plug 2 located between the ports 8 and 10, and a circumferential groove is formed in the land portion of the plug 2 located between the ports 8 and 10. A liquid seal means is provided which is a combination of a seal 13 and a seal hold 14 which are brought into pressure contact with the peripheral wall of the plug insertion hole of the housing 1.

[Problems to be solved by the invention] However, in the above-mentioned conventional brake pressure holding device, the valve seat 3 is press-fitted into the plug 2 to form a metal seal, so there were the following problems. .

The outer periphery of the valve seat 3 to be press-fitted has a groove for assembling the seal 13 to the plug 2 and is thin, so the press-fitting load must be strictly controlled.
Care must be taken to ensure that the diameter does not increase due to press fitting.

There is a risk that press-fit burrs will occur, which poses a problem that will have an adverse effect on the built-in movable parts.

In order to confirm the sealability of the metal seal surface, it is essential to check for internal leaks during assembly.

Since the plug 2 and the valve seat 3 are integrated using a press-fitting method, the hardness of the valve seat 3, which is a press-fitted part, cannot be set higher than necessary, and foreign matter is found on the sealing surface due to insufficient hardness relative to the ball valve body 4. This may cause dents or the sealing surface may wear out due to the flow of foreign matter.
It was not possible to provide sufficient durability.

The present invention has focused on the above-mentioned problems, and aims to provide a brake pressure holding device having a structure that does not have the problem of internal leakage and can particularly improve the strength and durability of the valve seat portion.

[Means for Solving the Problems] In order to achieve the above object, the brake pressure holding device according to the present invention includes a valve seat provided in a plug that forms an oil passage interposed in a brake line from a master cylinder. A braking pressure holding device in which a valve body is disposed in the brake pressure holding device, and the valve body is sandwiched between a valve body support member having a built-in plug and an electromagnetic drive means operated by a control signal, wherein the valve body support member is built in. The plug is divided into a fitting structure with a sealing material interposed, an insertion opening for the valve body support member is formed on the divided end side of one divided plug, a valve seat is formed on the opposite end side, and the other divided plug is The plug is configured to fit into the one split plug so as to close the insertion opening on the one end side of the one split plug.

[Function] According to the above configuration, since the plug is divided, there is no problem in assembling the valve body support member into the built-in part, and since the valve seat is formed directly on one of the split plugs, By increasing the hardness of the plug itself, it is possible to increase the hardness of the valve seat and improve durability. Further, since there are no press-fitted parts, there are no manufacturing problems associated with press-fitting or internal leakage of hydraulic pressure, and there is an advantage that there is no need to check for leaks, especially for press-fitted metal seals.

[Example] Hereinafter, an example of the braking pressure holding device according to the present invention will be described in detail with reference to the drawings.

FIG. 1 is a sectional view of a brake pressure holding device according to an embodiment. As shown in the figure, this device includes a plug insertion hole 22 provided in a housing 20, and
A pair of divided plugs 24A and 24B are inserted in a fitted state and fixed and held with bolts 26. The plugs 24, 24A, 24B are a cylindrical female plug 24A with a bottom and a female plug 24.
It consists of a substantially cylindrical male plug 24B equipped with an insertion cylinder part 28 that is inserted into the opening of A,
The structure is such that a seal 30 is interposed on the outer peripheral surface of the insertion tube portion 28 and the insertion tube portion 28 is fitted and connected. The inner cavity formed by the fitting of both the split plugs 24A and 24B has a spring 32 and a spring 32 thereby forming the plug 24.
The valve opening rod 34 is biased toward the distal end of the valve body supporting member 36. In this case, the opening on the split end side of the male plug 24B is the insertion opening 39 of the valve body support member 36.
It is said that On the other hand, a conical valve seat 40 is provided on the outer surface of the tip of the male plug 24B opposite to the insertion port 39.
is directly formed, and the tip of the valve opening rod 34 faces the center of the valve seat 40. A valve chamber 42 is formed between the inner wall surface of the plug insertion hole 22 and the male plug 24B facing the valve seat 40, and a ball valve body 44 is accommodated therein.

On the other hand, the housing 20 includes the ball valve body 4.
The electromagnetic drive means 4 is located on the opposite side of the plug 24 across the plug 24.
6 is installed. This means 46 is the solenoid 4
8 and a push rod 50 that is activated by energizing the solenoid 48.
0 is located symmetrically on the same axis as the valve opening rod 34 and faces into the valve chamber 42. Then, by pushing the push rod 50, the ball valve body 44
is pressed against the valve seat 40 against the valve opening force of the valve opening rod 34, thereby isolating the valve chamber 42 from the storage portion 38 within the plug 24.

The housing 20 is provided with an inlet port 52 that serves as a communication path to a master cylinder (not shown) and an outlet port 54 that serves as a communication path to a brake (not shown). The inlet port 52 opens on the outer peripheral surface of the tip of the plug 24 corresponding to the valve chamber 42, and communicates with the valve chamber 42 through a communication passage 56 formed at the tip of the plug 24B. The outlet port 54 is opened at a portion facing a radiation passage 58 formed in the body of the male plug 24 and communicates with the housing portion 38 of the valve element support member 36. In addition, the male plug 24B is connected to the inlet port 5.
Concave grooves 60 and 62 are formed in the facing part between the outlet port 54 and the outlet port 54.
A land portion 64 is provided in the intermediate portion by forming a land portion 64 . This land portion 64 has a port 52,
To prevent short circuit of 54, seal hold 66
A liquid sealing means consisting of a seal 68 and a seal 68 is provided. Further, an O-ring seal 70 is also provided on the outer periphery of the female plug 24A to provide a liquid seal between the female plug 24A and the plug insertion hole 22.

The braking pressure holding insertion hole 22 having such a configuration operates as follows. In normal running conditions, as shown in FIG. 1, the valve body support member 36 in the plug 24 presses the valve body 44 to open the valve, so the hydraulic pressure entering from the inlet port 52 is The brake pressure from the master cylinder is applied to the brake through the passage 56, the valve chamber 42, the housing 38, and the radial passage 58 to the outlet port 54. On the other hand, when the electromagnetic drive means 46 is activated due to vehicle stop detection, etc., the ball valve body 44 comes into contact with the valve seat 40 and blocks the oil passage, so there is no passage for the hydraulic pressure from the brake side to escape, and the hydraulic pressure is reduced. will be contained. As a result, braking pressure can be maintained when the vehicle is stopped.

By the way, in the above embodiment, the conventional structure in which the valve seat was press-fitted into the plug was stopped, and the plug 24
Since the valve seat 40 is formed directly on one of the plugs 24B using a male-female mating structure, the hardness of the plug 24B itself on which the valve seat 40 is formed can be increased, and in particular, the hardness of the valve seat 40 can be increased. The hardness can be made equal to the hardness of the ball valve body 44. Therefore, the strength and wear resistance of the valve seat 40 can be improved (hardness H _RC 28 to 45), and there are no problems with press-fitting loads, press-fitting burrs, or internal leaks on the metal seal surface. It disappears. Also, when installing the valve body support member 36 inside the plug 24, the female plug 24A and the male plug 24B are separated, and the spring 3
2 and valve opening rod 34 are built into both plugs 24.
It is only necessary to fit A and 24B together, and assembly can be performed in a sub-assembly state, thereby facilitating the assembly work. Further, in the sub-assembly state of the plug 24, the male plug 24B is prevented from separating and falling off due to the tightness of the seal 30 disposed on the outer peripheral surface of the insertion cylinder portion 28 of the male plug 24B.

In the above embodiment, the spring 32 and the valve opening rod 34 are built in the plug 24, but the spring 32 and the valve body 44 are built in to form the valve seat 40 in the plug 24, and the inlet port 52 and the outlet port 54 may be exchanged to provide a braking pressure holding device in which the valve opening operation is retracted by the pressure of the push rod 50 to perform the valve opening operation.

[Effects of the invention] As explained above, according to the invention, the plug is divided into a fitting structure with a seal interposed, and the valve seat is formed directly on one of the divided plugs, so that the valve seat is formed directly on one of the divided plugs. Internal leakage of hydraulic pressure and manufacturing difficulties are completely eliminated, and the braking pressure holding device is extremely easy to assemble, and the hardness of the valve seat portion is increased, making it durable.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a brake pressure holding device according to an embodiment, and FIG. 2 is a sectional view of a conventional example and the same device. 20...Housing, 24, 24A, 24B...
... plug, 36 ... valve body support member, 39 ... insertion port, 40 ... valve seat, 44 ... valve body, 46 ... electromagnetic drive means.

Claims (1)

[Scope of utility model registration request] An electromagnetic drive means in which a valve body is disposed on a valve seat provided in a plug that forms an oil path interposed in a brake line from a master cylinder, and the valve body is actuated by a valve body support member built into the plug and a control signal. In the braking pressure holding device, the plug containing the valve body support member has a two-part structure, and the two are fitted with a sealing material,
An insertion port for the valve body support member is formed at one end of one of the split plugs, and a valve seat is formed at the other end, and the other split plug closes the insertion port at the one end of the one split plug. A braking pressure holding device that fits into one of the split plugs as shown in FIG.