KR100423647B1 - 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 its object is to improve 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 the anti-lock brake system according to the present invention, the outer diameter (D1) is formed to be reduced in the lower end of the magnet core (31a), the lip seal (35) is fitted in the upper direction from the bottom to the coupling A small diameter portion 31e is provided, and a filter member 36 having an oil outlet 36e formed on the outer circumference thereof while supporting the lower end of the lip seal 35 at the bottom of the bore 81. Accordingly, the lip seal 35 performing the check valve function can be easily assembled and the damage can be prevented at the same time, and the braking pressure is immediately released through the oil outlet 36e when the braking action is released. There is this.

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 axially disposed inside 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. Accordingly, 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, and the other part of the inner periphery of the bore 4a and the lower end of the magnet core 1a. 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. This causes the braking pressure not to be released immediately, so if you take your foot off the brake pedal it will not be restored immediately.

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 its 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 35. Lip Seal

36. Filter element 36e. Oil outlet

In order to achieve the above object, the present invention provides a magnet core in which an inlet and an outlet are formed at a lower portion coupled to a bore of a modulator block, and an orifice perforated valve seat is disposed in an axial direction, and mounted on an upper portion of a magnet core. A normal sleeve which is installed to surround the sleeve, and a coil assembly that forms a magnetic field when the power is applied, and is built into the sleeve so as to move up and down, and the amateur descends when the power is applied to the coil assembly, and penetrates the magnet core so as to interlock with the armature. A normal open solenoid valve for an anti-lock brake system having a plunger disposed to open and close an orifice, and an annular lip seal installed under the magnet core to perform a check valve function.

The lower end of the magnet core is formed to have a reduced outer diameter so that the lip seal is fitted in the upper direction from the bottom to the small diameter portion is provided,

A filter member is provided at the bottom of the bore to support the lower end of the lip seal and prevents foreign substances from entering and exiting the filter member, and an oil outlet is formed at the outer circumference of the filter member so that oil flowing out through the outside of the lip seal is discharged. Configuration.

In addition, the filter member is provided with a fixing member having a cylindrical side that is press-fitted to the bottom of the bore and the bottom of the communication hole perforated, and a strainer provided to cover the communication port, the upper portion of the fixing member in contact with the lower end of the lip seal The outward flange portion having an inner diameter larger than the outer diameter of the small diameter portion is provided to accommodate the end of the neck portion with ease, and the oil outlet is configured to be formed axially on the outer periphery of the outward flange portion.

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 34a 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 arranged to move up and down through the inside of the magnet core 31a, so that the valve surface 33c opens and closes the orifice 34a. To this end, a return spring 33d is provided between the lower portion of the plunger 33b and the upper portion of the valve seat 34 to elastically support the plunger 33b in an upward direction. Therefore, the valve surface 33c of the plunger 33b normally keeps the orifice 34a open by the return spring 33d. This return spring 33d is composed of a kind of coil spring.

On the other hand, the lower portion of the magnet core 31a located at the bottom of the bore 81 is coupled to have a predetermined clearance with the inner circumference of the bore 81, the outer lip seal 35 of the elastic material to perform a check valve function Lip seals are placed. The lip seal 35 allows oil to flow out from the top of the outer periphery of the lower portion of the magnet core 31a, but prevents oil from entering the bottom from the top. The ring seal has a predetermined inner diameter D2. The body 35a, and is provided along the edge of the body 35a and has an elastic piece 35b composed of a free end to enable elastic deformation in the radial direction.

The lip seal 35 is assembled from the lower end to the upper end of the magnet core 31a in an upward direction, and the body 35a of the lip seal 35 is disposed at the outer periphery of the lower end of the magnet core 31a to facilitate assembly thereof. ) A small diameter portion 31e having an outer diameter D1 substantially the same as the inner diameter D2 is provided stepwise. Accordingly, by attaching to the small diameter portion 31e without artificially expanding the lip seal 35, its assembly work is made easier and no damage is caused.

In addition, at the bottom of the bore 81 to which the magnet core 31a, to which the lip seal 35 is assembled, is press-fitted, a filter member 36 for preventing entry of foreign matter is provided.

The filter member 36 includes a fixing member 36a having a cylindrical side surface and a bottom surface on which the communication port 36b is perforated, and a mesh-shaped filter net 36c provided to cover the communication port 36b. The side inner diameter D3 of the fixing member 36a is configured to be slightly larger than the outer diameter D1 of the small diameter portion 31e, and accommodates and arranges the ends of the small diameter portion 31e internally when the magnet core 31a is assembled.

In addition, an outward flange portion 36d having a diameter expanded to be press-fitted to the bottom of the bore 81 is integrally formed at the upper side of the fixing member 36a, and an oil outlet 36e is formed in the outer circumference thereof. A plurality of oil outlets 36e are provided to be spaced apart by a predetermined interval, which is to guide oil coming out through the lip seal 35 to the master cylinder 11 side.

Accordingly, after the filter member 36 is press-fitted to the bottom of the bore 81, and the magnet core 31a on which the lip seal 35 is disposed is mounted on the bore 81, the lip seal 35 is formed at the upper end diameter portion ( 31e) abuts on the stepped portion 31f formed by the processing and abuts on the upper surface of the outward flange portion 36d of the filter member 36, which has a wide bottom, and is firmly fixed. At this time, inside the filter member 36, the end of the small diameter portion 31e is accommodated so as to have a predetermined clearance.

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 normally the NO-type solenoid valve 30 is maintained in the open state, the braking hydraulic pressure in the direction of the arrow shown in Figure 3 is the hydraulic pressure through the filter member 36 → orifice 34a → 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. The orifice 34a is closed by In this state, oil is discharged from the hydraulic brake 20 side through the NC-type solenoid valve 40 which is opened, 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.

As such, during the ABS control, the NO-type solenoid valve 30 according to the present invention repeatedly opens and closes the opening and closing operation of the orifice 34a according to the lifting and lowering motion of the valve device 33.

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 axially provided on the outer circumference of the filter member 36. It is transmitted to the lip seal 35 side through the oil discharge port 36e, 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 only through the orifice 34a 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 release passage is formed between the lower outer circumference and the inner circumference of the bore 81. At this time, since the lower end of the lip seal 35 abuts on the upper surface of the outward flange portion 36d of the filter member 36, the phenomenon between the clearance does not occur.

Therefore, a part of the braking pressure coming out of the hydraulic brake 20 side exits to the master cylinder 11 side through the communication port 36b of the outlet 31c → the orifice 34a → the filter member 36, and the other part of the bore (81) A pressure release flow path formed between the inner circumference and the outer circumference of the lower end of the magnet core 31a → exits to the master cylinder 11 side through the oil discharge port 36e.

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.

As described above in detail, according to the normally open solenoid valve for the anti-lock brake system according to the present invention, the outer diameter is reduced in the lower end of the magnet core is provided with a small diameter portion that is lip seal is fitted in the upper direction from the bottom to the coupling At the bottom of the bore, the lower end of the lip seal is supported, and at the same time a filter member having an oil outlet is formed on the outer periphery. 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 a lower portion of the modulator block, and a magnet seat having an orifice perforated valve seat disposed axially therebetween, a conventional sleeve mounted on an upper portion of the magnet core, and the sleeve A coil assembly which is installed to surround and forms a magnetic field when the power is applied, and is built into the sleeve so that the coil assembly can be lowered and lowered when the power is applied to the coil assembly, and is disposed through the magnet core so as to interlock with the armature. In the normally open solenoid valve for an anti-lock brake system having a plunger for opening and closing the plunger, and an annular lip seal installed at a lower portion of the magnet core to perform a check valve function, A small diameter portion 31e is formed at the lower end of the magnet core 31a so that the outer diameter D1 is reduced so that the lip seal 35 is inserted into the upper direction from the lower portion thereof and coupled thereto. A filter member 36 supporting a lower end of the lip seal 35 and preventing entry of foreign matters is disposed at the bottom of the bore 81, and the lip seal 35 is formed on an outer circumference of the filter member 36. Normally open solenoid valve for an anti-lock brake system, characterized in that the oil outlet (36e) is formed so that the oil coming out through the outside of the). The method of claim 1, The filter member 36 is installed to cover the communication member 36a and the fixing member 36a having a cylindrical side to be press-fitted to the bottom of the bore 81 and a bottom surface of the communication hole 36b. With a sieve 36c, The inner diameter D2 is larger than the outer diameter D1 of the small diameter portion 31e so that the upper end of the small diameter portion 31e can be accommodated in an upper portion of the fixing member 36a in contact with the lower end of the lip seal 35. A largely formed outward flange portion (36d) is provided, the oil discharge port (36e) is a normal open solenoid valve for an anti-lock brake system, characterized in that formed in the axial direction on the outer periphery of the outward flange portion (36d).