JPH074553A - Solenoid valve - Google Patents

Abstract

PURPOSE:To dispense with air vent operation after assembling and facilitate maintenance by providing a seal member which keep fluid-tightness between a rod and a core when the rod is at a receding position, between a core and the rod which is connected to a plunger electromagnetically driven. CONSTITUTION:A solenoid valve adopted to a brake liquid pressure controlling device or the like is prepared by fitting a coil support member 56 housing a cylindrical coil 54 into a cylindrical main body 50, and concentrically arrange a plunger 60 and a core 62 on its inner peripheral part. One end of a rod 68 is press-fitted into the plunger 60, while the other end of the rod 68 is slidably fitted to a through-hole 64 of the core 62. A valve body 74 is provided on a large end of the rod 68. A valve seat member 84 is arranged oppositely to the valve body 74. A seal surface 66 is formed on an opening surface of the through-hole 64 of the core 62, on the side facing a valve chamber 86. A seal surface 76 is formed on the surface opposed to the rod 68, and then a seal means is prepared. The through-hole 64 is sealed when the rod 68 is at a receiding position.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a solenoid valve.

[0002]

2. Description of the Related Art An electromagnetic valve is used in a brake fluid pressure control device, an example of which is described in Japanese Utility Model Laid-Open No. 2-38744. This solenoid valve consists of (a) a cylindrical coil, (b) a plunger that is concentrically arranged inside the coil, and is moved forward by energizing the coil, and (c)
Arranged concentrically with the plunger in front of the plunger,
A core having a through hole on the center line, and (d) the intermediate portion is slidably fitted in the through hole of the core, the rear end portion is engaged with the plunger, and the valve element is provided at the front end portion. (E) A valve chamber surrounding the valve is formed, and a first port and a valve seat around the first port are provided at a position facing the valve, and a second port is provided at another position. It includes a fixing member provided, (f) a spring for urging the valve element in a direction away from the valve seat, and (g) an air venting means for venting air around the plunger. The air bleeding means is composed of a female screw hole formed in the main body and a plug detachably provided in the female screw hole.

This solenoid valve is installed in the brake fluid pressure control device so that air does not exist around the plunger. The rod is always at the retracted end position due to the urging force of the spring, the valve element is separated from the valve seat, and the first port and the second port are in communication with each other through the valve chamber. The energization causes the plunger to move forward against the urging force of the spring, which in turn causes the rod to move forward, causing the valve element to sit on the valve seat and disconnect the first port and the second port. It

However, during assembly, air may remain around the plunger or air in the liquid passage may flow in. If air exists around the plunger, the air is compressed when the hydraulic pressure in the valve chamber rises. Therefore, in this solenoid valve, when the hydraulic fluid is supplied from one of the first port and the second port to the other, a part of the hydraulic fluid flows into the vicinity of the plunger, and the extra hydraulic fluid is required. As a result, there arises a problem that the supply of the hydraulic fluid to the other port is delayed.

In particular, when the solenoid valve is provided in the middle of the fluid passage connecting the master cylinder and the wheel cylinder of the brake fluid pressure control device, one of the hydraulic fluid supplied from the master cylinder to the wheel cylinder is provided. Since the part flows into the vicinity of the plunger, the braking effectiveness is delayed accordingly. In order to avoid this problem, the air around the plunger must be appropriately evacuated by the evacuating means.

[0006]

As described above, in the conventional solenoid valve, the solenoid valve must be assembled so that air does not exist inside, so that there is a problem that the assembly work becomes troublesome. . In addition, since the air accumulated around the plunger must be appropriately removed even after the assembling, there is a problem that the maintenance is troublesome. Further, since the air venting means must be provided, there is a problem that the structure becomes complicated accordingly. Therefore, an object of the present invention is to obtain an electromagnetic valve that facilitates maintenance and can reduce costs.

[0007]

The gist of the present invention resides in the above (a) coil, (b) plunger, and
(c) In a solenoid valve including a core, (d) rod, (e) fixing member, and (f) spring, when the rod is at the retracted end position between the front end of the rod and the core, It is to provide a sealing means for maintaining liquid tightness between the rod and the core. The sealing means may be any means as long as it maintains the liquid tightness between the rod and the core. For example, the front end portion of the rod and the core are in close contact with each other to prevent the liquid from flowing. The pair of sealing surfaces may be formed.

[0008]

In the solenoid valve of the present invention, the sealing means provided between the front end of the rod and the core maintains liquid tightness between the rod and the core when the rod is at the retracted end position. . Therefore, when the rod is at the retracted end position and the first port and the second port are in communication with each other, the hydraulic fluid is prevented from flowing into the vicinity of the plunger from between the rod and the core. Therefore, the supply delay of the hydraulic fluid when the hydraulic fluid is supplied from one of the first port and the second port to the other port is avoided.

Further, when the solenoid valve of the present invention is arranged in the middle of the fluid passage connecting the master cylinder and the wheel cylinder of the brake fluid pressure control device, the working fluid from the master cylinder flows into the vicinity of the plunger. Instead, all is supplied to the wheel cylinders, so that a delay in braking effectiveness is avoided. There is no problem even if air is present around the plunger.

[0010]

Therefore, according to the solenoid valve of the present invention,
Since it is not necessary to perform the assembling work of the solenoid valve so that air does not exist inside, the assembling work can be easily performed. Further, since it is not necessary to vent the air even after the assembling, the maintenance becomes easy. Further, since the air venting means which is required in the conventional solenoid valve is not required, the structure can be simplified and the cost can be reduced accordingly.

[0011]

FIG. 2 shows a part of a hydraulic brake system equipped with a brake hydraulic pressure control device including an electromagnetic opening / closing valve according to an embodiment of the present invention. Reference numeral 10 is a brake pedal, 12 is a master cylinder, and 14 is a wheel cylinder. Liquid passage 16 connecting master cylinder 12 and wheel cylinder 14
A normally open electromagnetic on-off valve 18 is provided in the middle of the path, and another liquid passage 2 that connects the wheel cylinder 14 and the reservoir 19 is provided.
A normally closed electromagnetic on-off valve 22 is disposed in the middle of 0.
The electromagnetic on-off valves 18 and 22 are controlled based on a command from a control device (not shown). Further, the hydraulic fluid in the reservoir 19 is pumped up by the pump 26 and stored in the accumulator 28 at appropriate times.

The electromagnetic on-off valves 18 and 22 are always in the original position in the figure, the liquid passage 16 is in communication with the liquid passage 20, and the liquid passage 20 is closed. When the brake pedal 10 is depressed,
A hydraulic pressure is generated in the master cylinder 12 according to the pedaling force, and the hydraulic pressure is transmitted to the wheel cylinder 14 via the electromagnetic opening / closing valve 18. Further, when the hydraulic pressure of the wheel cylinder 14 becomes excessive in relation to the friction coefficient μ of the road surface, the electromagnetic opening / closing valves 18 and 22 are switched, the liquid passage 16 is shut off, and the liquid passage 20 is communicated. The hydraulic fluid in the wheel cylinders 14 is discharged to the reservoir 19 via the electromagnetic opening / closing valve 22, and the hydraulic pressure in the wheel cylinders 14 is reduced.

Next, the solenoid on-off valve 18 will be described in detail with reference to FIG. In FIG. 1, reference numeral 50 denotes a main body having a generally cylindrical shape, and one opening of the main body 50 has a plug 5
It is blocked by 2. The main body 50 and the plug 52 are made of a magnetic material. Inside the main body 50, a coil support member 56 made of a non-magnetic material, which has a cylindrical coil 54 built therein.
Are fitted and fixed. In addition, the coil support member 5
A plunger 60 and a core 62 made of a magnetic material are arranged concentrically with the coil 54 on the inner peripheral part of the sleeve 6 via a sleeve 58. The plunger 60 can be advanced by energizing the coil 54, and the core 62 is fixed to the main body 50 in front of the plunger 60. Also, core 6
A through hole 64 is formed on the center line of 2, and the opening on the front end face side of the through hole 64 is tapered to form a sealing surface 66.
Are formed.

A rod 68 is concentrically extended forward from the plunger 60. Rod 68 has a small diameter portion 70
And a large diameter portion 72. Plunger 60 at the rear end
And the middle part is slidably fitted in the through hole 64 of the core 62. A large diameter portion 72 is provided at the protruding end of the small diameter portion 70 from the core 62, and a valve element 74 is provided at the front end of the large diameter portion 72. In addition, the small diameter portion 7 of the large diameter portion 72
The corner on the 0 side is rounded to form a sealing surface 76.

The outer diameter of the plunger 60 is slightly smaller than the inner diameter of the sleeve 58, and the axial length of the plunger 60 is shorter than the distance between the plug 52 and the core 62. A first chamber 78 is formed in front of the plunger 60, and a second chamber 80 is formed in the rear of the plunger 60. Since there is a gap between the plunger 60 and the sleep 58, the first chamber 78 and the second chamber 80 are always in communication with each other.
With the movement of 0, the hydraulic fluid flows between the first chamber 78 and the second chamber 80.

A valve seat member 84 is fitted and fixed to the opening of the main body 50 opposite to the plug 52. The valve seat member 84 forms a valve chamber 86 that surrounds the valve element 74 together with the main body 50 and the core 62. A first port 88 is formed at a position of the valve seat member 84 facing the valve element 74, and the periphery of the first port 88 is a valve seat 90. A second port 92 is formed in the portion of the main body 50 surrounding the valve chamber 86. The master cylinder 12 is connected to the first port 88, and the wheel cylinder 14 is connected to the second port 92. In this way, the fixing member in the present invention is constituted by a part of the main body 50 and the valve seat member 84. A spring 98 is provided between the valve element 74 and the valve seat 90, and biases the valve element 74 in a direction away from the valve seat 90.

On the other hand, the main body 50 is formed with a communication passage 100 that bypasses the first port 88 and communicates with the second port 92, and the communication passage 100 is provided with a check valve 102. The check valve 102 blocks the flow of the hydraulic fluid in the direction toward the second port 92 and allows the flow in the opposite direction. Reference numerals 104 and 106 are filters.

As described above, the sealing surface 66 is formed in the opening of the through hole 64 of the core 62 on the front end surface side, and the rod 6
Since the seal surface 76 is formed on the rod 8,
Seal surface 7 when it has retracted to the retracted end position.
6 contacts the sealing surface 66, and liquid tightness between the core 62 and the rod 68 is maintained. These sealing surfaces 76
The sealing surface 66 constitutes the sealing means.

The operation of the electromagnetic control valve 18 constructed as above will be described. It is always in the original position shown. Disciple 7
4 is separated from the valve seat 90 by the urging force of the spring 98, the first port 88 and the second port 92 are communicated with each other, the rod 68 is located at the retracted end, and the seal surface 76 is in close contact with the seal 66. The liquid tightness between the rod 68 and the core 62 is maintained. Brake pedal 1
When 0 is depressed, hydraulic pressure corresponding to the pedaling force is generated in the master cylinder 12, and the hydraulic pressure of the master cylinder 12 is transmitted to the wheel cylinder 14 via the first port 88, the valve chamber 86, and the second port 92. To be done. In that case, since the liquid tightness between the rod 68 and the core 62 is maintained, the hydraulic fluid flowing into the valve chamber 86 is retained in the first chamber 78 and the second chamber 8.
Inflow around the zero degree plunger 60 is prevented.

When the hydraulic pressure of the wheel cylinder 14 becomes excessively large in relation to the friction coefficient μ of the road surface and the slip of the wheels becomes excessively large, the anti-skid control is started. The coil 54 is energized by a controller (not shown), the plunger 60 is advanced, and the rod 68 is advanced against the urging force of the spring 98. As a result, the valve element 74 is seated on the valve seat 90, the first port 88 and the second port 92 are shut off, and the supply of hydraulic fluid to the wheel cylinder 14 is stopped. At the same time, the solenoid opening / closing valve 22 is opened, and the hydraulic fluid in the wheel cylinder 14 is stored in the reservoir 1.
9 and the hydraulic pressure in the wheel cylinder 14 is reduced.

As described above, the solenoid opening / closing valve 18 of this embodiment is
In the above, in the state where the first port 88 and the second port 92 are in communication with each other, the liquid tightness between the rod 68 and the core 62 is maintained by the sealing means composed of the pair of sealing surfaces 66 and 76. The hydraulic fluid in the valve chamber 86 is prevented from flowing into the vicinity of the plunger 60 such as the first chamber 78 and the second chamber 80. Therefore, from the master cylinder 12 to the first port 88
All of the hydraulic fluid flowing into the valve chamber 86 via the second port 9
Since it is supplied to the wheel cylinder 14 after passing through 2, it is possible to avoid a delay in the braking effectiveness. That is, in the solenoid opening / closing valve 18 of the present embodiment, the first chamber 78
There is no problem even if there is air around the plunger 60 such as the second chamber 80, and it is not necessary to remove air from this portion.

The sealing means is not limited to the mode of the above embodiment, but may be, for example, the mode shown in FIG. In FIG. 3, an O-ring 210 is arranged on the step portion between the large diameter portion 202 and the small diameter portion 204 of the rod 200. On the other hand, a fitting hole 216 having a larger diameter than the through hole 214 is formed on the lower end surface of the core 212. When the rod 200 is located at the retracted end, the O-ring 210 is brought into contact with the fitting hole 216 to maintain liquid tightness between the rod 200 and the core 212. That is, the O-ring 210 and the fitting hole 21
The sealing means is constituted by 6 and 6.

Further, it is not always essential to provide the large diameter portion at the front end portion of the rod. When the large diameter portion is not provided, a groove may be formed near the front end portion of the intermediate portion of the rod, and the O ring may be fitted in the groove. When the rod is located at the retracted end, the O-ring is engaged with the through hole formed in the core, and the liquid tightness between the rod and the core is maintained. The O-ring and the through hole constitute a sealing means.

Further, in the above embodiment, the rod 6
8 is press-fitted into the plunger 60 so that the rod 6
Although 8 and the plunger 60 were able to move integrally, it is not essential to fix the rod 68 to the plunger 60. Although not shown, the rod is fitted in a fitting hole formed in front of the plunger, and a spring for urging the plunger in the direction of bringing the plunger into contact with the rod is provided in the second chamber. In this case, the elastic force of the spring is smaller than that of another spring arranged between the valve element and the valve seat that biases the rod in the backward direction. Normally, the rod is positioned at the retracted end by the above-mentioned other spring, but if the plunger is advanced by energizing the coil, the rod is advanced accordingly. In this way, they can be moved together without fixing the rod to the plunger.

Further, in the above embodiment, the case where the solenoid valve of the present invention is applied to the solenoid opening / closing valve has been described, but it may be applied to the solenoid directional control valve. In that case, two or more seat valves may be combined.

Although not specifically exemplified, the present invention can be implemented in various modified and improved modes without departing from the scope of the claims based on the knowledge of those skilled in the art.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an electromagnetic opening / closing valve that is an embodiment of the present invention.

FIG. 2 is a partial circuit diagram of a hydraulic brake device including the electromagnetic opening / closing valve.

FIG. 3 is a sectional view showing a main part of an electromagnetic opening / closing valve according to another embodiment of the present invention.

[Explanation of symbols]

 18 Electromagnetic on-off valve 54 Coil 60 Plunger 62,202 Core 66 Sealing surface 68,200 Rod 74 Valve 76 Sealing surface 84 Valve seat member 98 Spring 210 O-ring 216 Fitting hole

Claims (1)

[Claims] 1. A cylindrical coil, a plunger arranged concentrically inside the coil and advanced by energizing the coil, and arranged in front of the plunger concentrically with the plunger,
A core having a through hole on its center line, a rod having an intermediate portion slidably fitted in the through hole of the core, a rear end portion engaged with the plunger, and a valve element provided at a front end portion. And a fixing member that forms a valve chamber that surrounds the valve element, includes a first port at a position facing the valve element and a valve seat around the first port, and has a second port at another position, In a solenoid valve including a spring that biases a valve element in a direction away from a valve seat, between a rod and a core between the rod and the core when the rod is at a retracted end position between the front end portion of the rod and the core. A solenoid valve provided with a sealing means for maintaining liquid tightness.