KR100423648B1 - Normal open type solenoid valve for ABS - Google Patents

Abstract

The present invention relates to a normally open solenoid valve for an anti-lock brake system, and an object thereof is to improve the assembly workability of a lip seal performing a check valve function and to prevent damage thereof.

According to the normally open solenoid valve 30 for an anti-lock brake system according to the present invention, a valve composed of a small diameter portion 34a, a large diameter portion 34c, and an outward flange portion 34e having an oil outlet 34f formed along an edge thereof. After the lip seal 35 that performs the check valve function is previously mounted on the seat 34, the valve seat 34 is coupled to the magnet core 31a. Accordingly, the assembly of the lip seal 35 performing the check valve function is more easily performed, and at the same time, the damage is prevented. When the braking action is released, the braking pressure is immediately released through the oil outlet 34f. have.

Description

Normal open type solenoid valve for anti-lock brake system

The present invention relates to an anti-lock brake system, and more particularly, to a normally open solenoid valve for an anti-lock brake system, which is closed or open during ABS control to control braking hydraulic pressure, but is normally kept open.

In general, a vehicle is equipped with a hydraulic brake for braking the front wheels and the rear wheel, a power booster for forming and transmitting a braking hydraulic pressure to the hydraulic brake side, a master cylinder, and the like. Since a cylinder or the like is mounted, a brake hydraulic pressure is formed when the driver presses the brake pedal, which is transmitted to the hydraulic brake to generate a braking force.

However, when the driver presses the brake pedal to control the increase / maintenance of the braking force, if the braking pressure is greater than the road surface or the friction force of the hydraulic brake is greater than the braking force generated from the tire or the road surface, the tire slips on the road surface. Is generated.

The anti-lock brake system is an anti-lock brake system that effectively prevents such slip phenomenon and obtains a strong and stable braking force. This includes a plurality of solenoid valves and accumulators for controlling the braking hydraulic pressure delivered to the hydraulic brake side. And an ECU for controlling the pump and the electric drive element.

The valve assembly of the accumulator, the pump and the solenoid valve is compactly provided in the modulator block made of aluminum, and the coil assembly of the solenoid valve and the circuit board for controlling the driving of the pump and the solenoid valve are disposed in the ECU.

At this time, the solenoid valve is divided into a normal open solenoid valve disposed on the upstream side of the hydraulic brake and normally kept open, and a normally closed solenoid valve disposed on the downstream side and normally closed.

Referring to FIG. 1, a conventional normal open solenoid valve (hereinafter referred to as a NO solenoid valve) is fixed to a modulator block 4 and has a valve assembly in which an orifice 1d is perforated with a valve seat 1e disposed in an axial direction. (1) and a coil assembly 2 composed of a kind of solenoid wound around the coil 2a to form a magnetic force upon application of current.

The valve assembly 1 is provided with an inlet 1b and an outlet 1c and a magnet core 1a having a lower portion where the valve seat 1e is disposed in the inlet 1b is mounted on the bore 4a of the modulator block 4. And a normal sleeve 1f press-fitted to the upper portion of the magnet core 1a exposed to the outside of the modulator block 4, and the magnet core 1a is moved back and forth by a magnetic force to provide the orifice 1d. A valve device 3 for opening and closing operation is provided. The inlet 1b is associated with the hydraulic line on the master cylinder side, and the outlet 1c is associated with the wheel cylinder side of the hydraulic brake (not shown) and the inlet of a normal closed solenoid valve (not shown).

The valve device 3 has an armature 3a built in the sleeve 1f so as to be able to move up and down in an up and down direction, and a plunger 3b having a spherical body 3c extending in the shape of a rod under the armature 3a. It is provided. The plunger 3b is slidably disposed axially in the magnet core 1a together with the armature 3a, so that the sphere 3c opens and closes the orifice 1d of the valve seat 1e. In addition, a coil spring type return spring 3d is disposed between the lower end of the plunger 3b and the upper end of the valve seat 1e for the return of the armature 3a. As a result, the spherical body 3c of the plunger 3b is normally kept open by the orifice 1d by the elastic support force of the return spring 3d. (In the case of a normally closed solenoid valve, the sphere of the plunger will normally keep the orifice closed.)

On the other hand, the lower portion of the magnet core (1a) in which the valve seat (1e) is arranged in the axial direction is coupled to have a predetermined clearance with the inner circumference of the bore (4a), the lip seal provided with an elastic material to perform a check valve function on the outer circumference thereof (5, lip seal) is installed. That is, the lip seal 5 is provided in an annular shape having an elastic piece 5a at its edge, and an annular seating groove 1g is machined on the outer periphery of the lower end of the magnet core 1a for its installation.

Accordingly, the lip seal 5 fitted to the annular seating groove 1g is radially opened in close contact with the inner circumference of the bore 4a when a braking pressure is applied, whereby the braking pressure is inlet ( 1b) → It is transmitted to the hydraulic brake side via the orifice 1d → the outlet 1c. On the other hand, at the time of releasing the braking pressure, the elastic piece 5a is retracted toward the center by the hydraulic pressure that is released, so as to be spaced apart from the inner circumference of the bore 4a to form a pressure releasing passage. As a result, a part of the braking pressure coming out of the hydraulic brake side exits to the master cylinder side through the outlet 1c → the orifice 1d → the inlet 1b. Exit through the clearance between the outer periphery.

However, in such a conventional normal open solenoid valve, since the lip seal 5 performing the check valve function is inserted into the seating groove 1g in an artificially expanded state, the lip seal 5 is often damaged. do.

That is, since the outer diameter of the inlet portion 1h of the seating groove 1g for preventing the detachment of the lip seal 5 is configured to be larger than the inner diameter of the lip seal 5, the lip seal 5 is sometimes torn during the assembly process. There are disadvantages to losing.

In addition, the end of the lip seal 5 is pushed between the inlet portion 1h of the seating groove 1g and the inner circumference of the bore 4a to permanently or temporarily block the pressure release passage. As a result, the braking pressure is not released immediately, and this phenomenon causes the case that it is not immediately restored even when the foot is released from the brake pedal.

The present invention is to solve this problem, the object of the present invention is to improve the installation structure of the lip seal to perform the check valve function to prevent the damage during the assembly process and also to release the braking pressure immediately when the braking action is released. To provide a normally open solenoid valve for an anti-lock brake system.

1 is a cross-sectional view showing the internal configuration of a conventional normal open solenoid valve.

2 is a hydraulic system diagram of an anti-lock brake system to which the present invention is applied.

3 to 5 show the internal configuration and operation of the normal open solenoid valve according to the present invention.

* Description of the symbols for the main parts of the drawings *

30. Normally open solenoid valve 31. Valve assembly

31a .. Magnet Core 31b .. Inlet

31c..Outlet 31d..Sleeve

33. Valve device 34. Valve seat

34a.Orifice 34b. Orifice

34c .. Daekyung 34d .. Oil passage

34e.Outward flange 34f.Oil drain

35..lip seal

The present invention for achieving this object,

An inlet and an outlet formed at one end coupled to the bore of the modulator block, and a magnet core equipped with a conventional sleeve at the other end exposed to the outside of the modulator block, a coil assembly installed to surround the sleeve to form a magnetic field when the power is applied; It is built in the sleeve so as to move up and down, and the armature descends when the coil assembly is turned on, the plunger disposed through the magnet core in the axial direction so as to interlock with the armature, and is fitted into the inlet to be opened and closed according to the lifting movement of the plunger. In a normally open solenoid valve for an anti-lock brake system having a valve seat with an orifice perforated in an axial direction and an annular lip seal installed at one end of a magnet core to perform a check valve function,

The valve seat has a small diameter portion having an orifice perforated, a diameter extending from the small diameter portion, a large diameter portion having an upper portion press-fitted in the inlet, and an oil passage provided in the axial direction, and an outward flange portion having a diameter extending under the large diameter portion. The lip seal is configured to be disposed between the outward flange portion and one end of the magnet core.

In addition, the outward flange portion of the valve seat is characterized in that the oil outlet is formed at regular intervals along the edge.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Briefly, the accompanying drawings, Figure 2 is a hydraulic system of the anti-lock brake system to which the present invention is applied, Figures 3 and 4 show the configuration of the NO-type solenoid valve according to the present invention.

As shown in FIG. 2, the anti-lock brake system to which the present invention is applied includes a plurality of solenoid valves 30 and 40 and a low pressure and high pressure accumulator 50 for controlling hydraulic pressure transmission to the hydraulic brake 20 side. 70, and a modulator block 80 in which a pair of pumps 61 and a motor 60 are incorporated, and an ECU (not shown) for controlling an electric drive element.

The modulator block 80 is composed of an aluminum cuboid block. A plurality of solenoid valves 30 and 40 are compactly arranged on one side of the modulator block 80 to control braking hydraulic pressure transmitted to the hydraulic brake 20 side, and opening and closing of the solenoid valves 30 and 40. Operation is controlled by an ECU that senses the vehicle speed via wheel sensors (not shown) disposed on the front and rear wheels, respectively.

The solenoid valve is connected to the upstream side of the hydraulic brake 20 and is normally open solenoid valve 30 (hereinafter, referred to as a NO type solenoid valve) that is normally kept open, and the downstream side of the hydraulic brake 20. It is distinguished from a normally closed solenoid valve 40 (hereinafter referred to as an NC solenoid valve) which is connected and normally closed.

3 and 4, the NO-type solenoid valve 30 according to the present invention is coupled to the modulator block 80 and the valve assembly 31, the valve device 33 is built, and forms a magnetic force when the power is applied. And a coil assembly 32 for operating the valve device 33.

The coil assembly 32 is a kind of solenoid. The coil assembly 32 is wound around the bobbin 32a to be wound around the sleeve 31d to be described later. When the power is applied under the control of the ECU, the valve device 33 is opened. It creates a magnetic force to actuate.

The valve assembly 31 is coaxially press-fitted with the magnet core 31a in which the inlet 31b machined in the axial direction and the outlet 31c machined in the radial direction and the inlet 31b are coaxially pressed into the shaft. The valve seat 34 in which the orifice 34b is drilled in the direction, and a cylindrical sleeve 31d coupled to the upper portion of the magnet core 31a. The lower part of the magnet core 31a is press-fitted to the bore 81 machined in the modulator block 80, whereby the inlet 31b is associated with the master cylinder 11 (see Fig. 2) and the outlet 31c is hydraulically It is associated with the inlet side of the brake 20 and the NC type solenoid valve 40.

The valve device 33 includes an armature 33a which moves up and down by interacting with a magnetic force in the sleeve 31d, and a plunger having a hemispherical valve face 33c extending at the tip and having a rod shape at the lower end thereof. 33b). The plunger 33b is loosely penetrated in the axial direction through the inside of the magnet core 31a, and is arrange | positioned so that it can raise and lower.

On the other hand, the orifice 34b of the valve seat 34 is opened and closed by the lifting and lowering motion of the plunger 33b, the detailed structure of which is as follows.

First, the lower end of the magnet core 31a on which the valve seat 34 is installed is provided to have an inner circumference of the bore 81 and a predetermined clearance.

The valve seat 34 has a small diameter portion 34a in which the orifice 34b is axially perforated, and a diameter is extended from the small diameter portion 34a so that the upper portion is press-fitted and fixed in the inlet 31b. ) And a large diameter portion 34c provided with an oil passage 34d in the axial direction so as to be in communication with each other), and an outward flange portion 34e formed to further extend a diameter in the lower portion of the large diameter portion 34c. At this time, the diameter of the outward flange portion 34e is preferably configured to be substantially the same as or slightly smaller than the inner diameter of the bore 81, a plurality of oil outlet 34f is formed at regular intervals on the edge portion thereof. The oil outlet 34f is for guiding oil exiting through the outside of the lip seal 35 to be described later to the master cylinder 11 side.

When the valve seat 34 configured as described above is provided in the inlet 31b of the magnet core 31a, the valve face 33c of the plunger 33b and the small diameter portion 34a of the valve seat 34 are normally spaced at regular intervals. The orifice 34b is spaced apart to be kept open. For this purpose, a return spring 33d is provided between the lower end of the plunger 33b and the upper portion of the valve seat 34 to elastically support the plunger 33b in an upward direction. This return spring 33d is composed of a kind of coil spring.

In addition, a lip seal 35 that performs a check valve function is disposed between the outward flange portion 34e of the valve seat 34 and the lower end portion of the magnet core 31a. The lip seal 35 is capable of flowing oil from the upper side to the lower side, but prevents oil from entering the upper side from the bottom, and has an annular body 35a having a predetermined inner diameter and the body 35a. It is provided along the edge of the elastic piece (35b) configured to be free end to enable expansion and contraction in the radial direction. At this time, the inner diameter of the body 35a is preferably configured to be the same as the diameter of the large diameter portion 34c of the valve seat 34.

The lip seal 35 is fitted to the large diameter portion 34c before the valve seat 34 is coupled to the magnet core 31a. That is, after the lip seal 35 is coupled to the lower side of the large diameter portion 34c through the small diameter portion 34a side of the valve seat 34, the valve seat 34 is installed on the inlet 34b of the magnet core 31a. The lip seal 35 is disposed between the lower end of the magnet core 31a and the outward flange portion 34e. Therefore, since the lip seal 35 is simply fitted in the downward direction from the upper portion of the valve seat 34, the assembling work is easily made and no damage thereof is caused.

Next will be described the operation and effect of the NO-type solenoid valve 30 according to the present invention configured as described above.

First, the general braking action is as follows. The braking hydraulic pressure generated in the master cylinder 11 by the driver stepping on the brake pedal 10 is transmitted to the hydraulic brake 20 through the NO type solenoid valve 30.

That is, since the NO-type solenoid valve 30 is normally maintained in the open state, the braking hydraulic pressure in the direction of the arrow shown in Figure 3 is hydraulic pressure through the oil passage (34d) → orifice (34b) → outlet (31c) The brake 20 is delivered to the brake 20 side. When the driver releases the brake pedal 10 little by little or completely, the braking hydraulic pressure in the hydraulic brake 20 is returned in the reverse order through the open NO solenoid valve 30 to reduce the braking force or to completely release the braking action. do.

On the other hand, in the case of ABS control that prevents the slip of the vehicle, the three modes of braking pressure decompression, boosting, and holding are controlled so that the NO type solenoid valve 30 controls the hydraulic pressure transmission to the hydraulic brake 20 side. The opening and closing operation is repeatedly performed.

That is, when the braking pressure in the hydraulic brake 20 is greater than the road surface condition in the state of braking, the pressure should be lowered to the appropriate pressure. In the ECU (not shown), the NO type solenoid valve 30 is closed and the NC type solenoid valve is operated. 40 is open operation.

Therefore, when power is applied to the coil assembly 32 of the NO solenoid valve 30, a magnetic field is formed and the plunger 33b comes down while compressing the return spring 33d together with the armature 33a, and the valve surface 33c. ) Orifice 34b is closed. In this state, the oil is discharged from the hydraulic brake 20 side through the NC-type solenoid valve 40 which is operated in an open manner, thereby lowering the braking pressure and preventing sliding from the road surface. At this time, the oil escaping from the hydraulic brake 20 is temporarily stored in the low pressure accumulator 50.

In addition, when the braking pressure decompression state lasts for a long time or the vehicle proceeds to a place where the friction coefficient of the road surface is high, the friction force that can be generated on the vehicle tire and the road surface than the braking pressure in the hydraulic brake 20 can be braked. This increases the vehicle braking efficiency. The ECU judges such a situation based on a signal input from each wheel sensor, and drives the motor 60 to operate the pump 61 to increase the braking pressure in the hydraulic brake 20. Therefore, the oil stored in the low pressure accumulator 50 is pressurized and supplied to the high pressure accumulator 70, and the power supply is continuously cut off and transferred to the hydraulic brake 20 through the NO type solenoid valve 30 which is opened. This increases the braking hydraulic pressure.

Thus, during the ABS control, the NO-type solenoid valve 30 according to the present invention, the opening and closing of the orifice 34b in accordance with the lifting and lowering movement of the valve device 33. The closing operation is made repeatedly.

At this time, when the valve device 33 is lifted and at the same time a braking pressure is applied from the master cylinder 11 side, as shown in FIG. 3, a part of the braking pressure is lip seal 35 through the oil discharge port 34f. It is transmitted to the side, whereby the elastic piece 35b extends in the radial direction and is in close contact with the inner circumference of the bore 81. Therefore, the braking pressure is transmitted to the hydraulic brake 20 side through the oil passage 34d, the orifice 34b, and the outlet 31c.

On the other hand, when the braking pressure is released through the NO-type solenoid valve 30, as shown in FIG. 5, the elastic piece 35b is retracted in the center direction by the hydraulic pressure and spaced apart from the inner circumference of the bore 81, thereby providing a magnet core. A pressure relief passage is formed between the lower outer periphery and the inner circumference of the bore 81. Accordingly, a part of the braking pressure coming out of the hydraulic brake 20 side exits to the master cylinder 11 side through the outlet 31c → the orifice 34b → the oil passage 34d, and the rest of the braking pressure passes through the inner circumference of the bore 81. It exits to the master cylinder 11 side through the pressure relief flow path formed between the outer periphery of the lower end of the magnet core 31a, and the oil discharge port 34f.

As a result, when the driver releases the brake pedal 10, the braking pressure is released immediately, thereby smoothly restoring the reliability of the overall braking system. In addition, since the lower end of the lip seal 35 which performs such a check valve function is abutted with the outwardly flanged portion 34e, which is widely configured, the phenomenon between the clearance of the bore 81 does not occur.

As described in detail above, according to the normally open solenoid valve for an anti-lock brake system according to the present invention, a check valve function is performed on a valve seat composed of a small diameter portion, a large diameter portion, and an outward flange portion having an oil discharge port formed along an edge thereof. After pre-mounting the lip seal, the valve seat is coupled to the magnet core. Accordingly, there is an advantage in that the assembly work of the lip seal performing the check valve function is more easily performed and damage is prevented, and the braking pressure is immediately released through the oil outlet when the braking action is released.

Claims (2)

An inlet and an outlet are formed at one end coupled to the bore of the modulator block, and a magnet core having a conventional sleeve mounted at the other end exposed to the outside of the modulator block, and a coil assembly installed to surround the sleeve to form a magnetic field when power is applied. An armature which is lowerably mounted in the sleeve and lowers when power is applied to the coil assembly, a plunger disposed through the magnet core in an axial direction so as to interlock with the armature, and fits into the inlet and is coupled to the inlet Normally open solenoid valve for an anti-lock brake system having a valve seat with an orifice perforated in the axial direction so as to be opened and closed according to the lifting and lowering motion of the magnet core, and an annular lip seal installed at one end of the magnet core to perform a check valve function. To The valve seat 34 has a small diameter portion 34a in which the orifice 34b is perforated, and a diameter is extended from the small diameter portion 34a so that the upper portion is press-fitted in the inlet 31b and oil in the axial direction. A large diameter portion 34c provided with a passage 34b, and an outward flange portion 34e formed to expand in diameter at a lower portion of the large diameter portion 34c; The lip seal (35) is a normal open solenoid valve for an anti-lock brake system, characterized in that disposed between the outward flange portion (34e) and one end of the magnet core (31a). The method of claim 1, Normally open solenoid valve for an anti-lock brake system, characterized in that the outward flange portion (34e) of the valve seat 34 is formed with an oil outlet (34f) at regular intervals along the edge.