KR20020009026A - Solenoid valve for ABS - Google Patents

Abstract

PURPOSE: A solenoid valve for an anti-lock brake system is provided to avoid the damage on a lip seal by fitting the lip seal in a seal combining unit of a magnet core and to improve assembling efficiency by installing a filter member in a filter combining unit via an elastic fixing piece. CONSTITUTION: A solenoid valve(30) for an anti-lock brake system includes a magnet core(31a) having an inlet(31b) and an outlet(31c) and a valve seat between the inlet and outlet(34), a lip seal(35) installed on the lower circumference of the magnet core to perform as a check valve, and a filter member(36) placed below the magnet core to block up contaminants. A seal combining unit(31e) cylindrically extended to be fitted with the lip seal and a filter combining unit(31f) having a taper face are prepared at the lowest end of the magnet core. The filter member has a frame(36a) having a filter screen(36b) and fixing pieces(36c) formed on the edge of the frame. Since the diameter of the filter combining unit is larger than the inner diameter of the lip seal, the lip seal is smoothly fitted in the seal combining unit by passing through the filter combining unit. If the filter member is forcibly fitted in the filter combining unit, the fixing pieces are widened and gradually combined to the filter combining unit.

Description

Solenoid valve for anti-lock brake system {Solenoid valve for ABS}

The present invention relates to an antilock brake system, and more particularly, to a solenoid valve for an antilock brake system that regulates braking hydraulic pressure by closing or opening in ABS control.

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.

In addition, a filter member 1i for preventing the inflow of foreign substances is mounted to the inlet portion of the inlet 1b immediately below the valve seat 1e through the caulking means. That is, the filter member 1i is fixedly arranged by the caulking unit 1j by caulking the filter member 1i at the bottom end of the magnet core 1a.

Therefore, in the case of applying the braking pressure, the elastic piece 5a of the lip seal 5 opens radially and closely contacts the inner circumference of the bore 4a, whereby the braking pressure is determined by the filter member 1i → inlet 1b → orifice ( 1d) → It is transmitted to the hydraulic brake side via 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 → the filter member 1i, and the rest of the braking pressure exits the inner circumference of the bore 4a. It exits through the clearance between the outer peripheries of the lower end of the magnet core 1a.

However, such a conventional solenoid valve has a disadvantage in that assembly work is difficult by caulking and fixing the filter member 1i at the lower end of the magnet core 1a to prevent the inflow of foreign substances.

In addition, 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. 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 in the process of assembling. There is a tearing problem.

The present invention is to solve this problem, the main object of the present invention to improve the installation structure of the filter member to improve its assembly workability and to provide a solenoid valve for an anti-lock brake system that can further reduce the manufacturing cost will be.

In addition, another object of the present invention is to provide a solenoid valve for an anti-lock brake system that can more easily install a lip seal performing a check valve function on the outer periphery of the lower end of the magnet core and prevent damage thereof.

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 and 4 show the internal structure of the normal open solenoid valve and the mounting structure of the filter member according to an embodiment of the present invention.

5 is an extract showing the mounting structure of the filter member according to another embodiment of the present invention.

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

30. Solenoid valve 31 a. Magnet core 31 b. Inlet

31c.Outlet 31e.Seal coupling part 31f.Filter coupling part

31g .. Tapered surface 31h. Jam groove 35. Lip seal

36. Filter element 36a Frame 36c Fixing piece

36f ..

The present invention for achieving this object,

An inlet and an outlet are formed at the lower end of the modulator block, which are fitted into the bore of the modulator block, and a magnet seat with an orifice perforated valve seat disposed axially therebetween, and installed at the outer periphery of the lower end of the magnet core to check between A solenoid valve for an anti-lock brake system having a lip seal performing a valve function and a filter member disposed under the magnet core to prevent foreign substances from entering the inlet side,

The lower end of the magnet core is provided with a seal coupling portion extending in a cylindrical shape so that the lip seal is fitted and coupled, and a filter coupling portion having a tapered surface extending gradually coaxially from the seal coupling portion and gradually increasing in outer diameter.

The filter member is provided with a frame provided with a strainer on the center, and a plurality of fixed at regular intervals along the edge of the frame is coupled to surround the filter coupling portion while elastically deformed, and at the same time the upper surface supports a lower end of the lip seal. It is a constitution.

In addition, the outer circumference of the filter coupling portion is provided with a recess groove,

Inside the fixing piece is characterized in that the locking step is provided elastically coupled to the locking groove.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. 2 is a hydraulic system diagram of an anti-lock brake system to which the present invention is applied, and FIGS. 3 and 4 show a configuration of a NO type solenoid valve to which an embodiment of the present invention is applied.

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 to which the present invention is applied is coupled to the modulator block 80 and forms a magnetic force upon application of a valve assembly 31 having a valve device 33 therein. 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 has a magnet core 31a having an inlet 31b machined in the axial direction and an outlet 31c machined in the radial direction at the lower end thereof, and a coaxial indentation in the inlet 31b. It includes a valve seat 34 in which the orifice 34a is perforated, and a cylindrical sleeve 31d coupled to the upper portion of the magnet core 31a. At this time, the lower end of the magnet core 31a is inserted into and fixed to the bore 81 machined in the modulator block 80, so that the inlet 31b is associated with the master cylinder 11 (see Fig. 2) and the outlet 31c. ) Is associated with the inlet side of the hydraulic brake 20 and the NC-type solenoid valve 40. Reference numeral "37" denotes an auxiliary orifice which is determined according to the vehicle (required liquid amount, vehicle characteristics) and press-fitted to the magnet core 31a.

The valve device 33 has an armature 33a which moves up and down by interacting with a magnetic force inside the sleeve 31d, and a plunger 33b extending in a rod shape at the lower end of the armature 33a and having a steel ball 33c disposed at its tip. ). The plunger 33b is arranged to move up and down through the inside of the magnet core 31a so that the steel ball body 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 steel ball body 33c of the plunger 33b is normally kept open in the orifice 34a by the return spring 33d. This return spring 33d is composed of a kind of coil spring.

On the other hand, the lower end of the magnet core (31a) located on the bottom of the bore 81 is coupled to have a predetermined clearance with the inner circumference of the bore 81, there is a lip seal (35, lip composed of an elastic material to perform a check valve function) seal) and a filter member 36 for preventing foreign matter from entering the inlet 31b side, and the detailed structure thereof is as follows.

First, at the bottom end of the magnet core 31a, the seal coupling portion 31e extends in a cylindrical shape to have a predetermined inner diameter D1, and extends coaxially from the seal coupling portion 31e, but the taper surface gradually increases in diameter. A filter coupling portion 31f having 31g is provided. At this time, the length L1 of the seal coupling portion 31e is the thickness of the lip seal 35 so as to be in contact with the fixing piece 36c of the filter member 36 to be described later in a state where the lip seal 35 is fitted. It is preferable to configure similarly to L2). In addition, it is preferable that the taper angle of the filter engagement portion 31f is appropriately adjusted so that the lip seal 35 can be expanded while being coupled without difficulty.

In addition, the lip seal 35 may allow oil to flow out from the top of the outer circumference of the lower portion of the magnet core 31a, but prevent oil from entering the bottom from the top. The predetermined thickness L2 and the inner diameter D2 may be prevented. It is provided with an annular body (35a) having a), and an elastic piece (35b) is provided along the edge of the body (35a) and configured with a free end to allow expansion and contraction in the radial direction. The lip seal 35 is mounted to the seal coupling portion 31e after passing through the filter coupling portion 31f, and the diameter of the filter coupling portion 31f is slightly larger than the inner diameter D2 of the lip seal 35. Because of that, they fit together without problems.

The filter member 36 is mounted to the filter coupling part 31f to prevent foreign substances from entering the inlet 31b and also supports the lower end of the lip seal 35. To this end, the filter member 36 includes a ring-shaped frame 36a provided with a mesh-type filter net 36b on the center portion thereof, and a plurality of fixing pieces 36c coupled to surround the filter coupling portion 31f while being elastically deformed. Include. The fixing piece 36c is formed at regular intervals along the edge of the frame 36a, and each inner surface 36e is inclined to be in surface contact with the tapered surface 31g of the filter coupling portion 31f, and the upper surface 36d. The flat surface is configured to support the lower end of the lip seal 35 while being in surface contact. The filter member 36 having the fixing piece 36c is preferably formed of a plastic material to have its own elastic force.

Next, the assembly process of the lip seal 35 and the filter member 36 of the NO type solenoid valve configured as described above and the effects thereof will be described.

First, the lip seal 35 is assembled to the seal coupling portion 31e of the magnet core 31a. At this time, since the lip seal 35 must pass through the filter engaging portion 31f composed of the tapered surface 31g, it is assembled while artificially expanding slightly.

And when the filter member 36 is forcibly inserted into the filter coupling portion 31f in the state where the lip seal 35 is assembled, the fixing piece 36c is gradually coupled to the filter coupling portion 31f while spreading outward. Subsequently, while restoring, the filter engaging portion 31f is wrapped while being in surface contact with the tapered surface 31g. As a result, the fixing piece 36c is elastically deformed and coupled to the filter coupling portion 31f, so that the filter member 36 is easily and firmly mounted, thereby allowing the filter from the filter coupling portion 31f without applying an artificial force. The member 36 is not detached. At this time, the upper surface 36d of the fixing piece 36c abuts and supports the lower end of the body 35a of the lip seal 35 as described above.

Therefore, since the lip seal 35 is inserted into the seal coupling portion 31e without any difficulty, the assembly is easily performed and is not damaged in the assembly process. In addition, the filter member 36 is mounted on the lower end of the magnet core 31a through the fixing piece 36c having its own elastic force, thereby making it easy and robust to assemble.

On the other hand, this technical idea is not limited to this, as shown in Figure 5, when forming the engaging groove 31h in the filter coupling portion 31f and providing the engaging jaw 36f in the fixing piece 36c, the filter The member 36 can be installed more firmly.

That is, the engaging groove 31h is formed in a ring-shaped recess on the outer circumference of the filter engaging portion 31f adjacent to the lower end of the body 35a of the lip seal 35. The locking jaw 36f is provided to protrude to the inside of the fixing piece 36c to elastically engage the locking groove 31h.

Therefore, when the filter member 36 is forcibly pressed into the filter engaging portion 31f, the locking jaw 36f is elastically coupled to the locking groove 31h, whereby the filter member 36 is more firmly mounted.

As described in detail above, according to the solenoid valve for the anti-lock brake system according to the present invention, the lip seal for performing the check valve function is inserted into the seal coupling portion formed on the lower end of the magnet core without any difficulty, so that the assembly is easy. It does not damage during assembly. In addition, the filter member is mounted to the filter coupling portion through the fixing piece having its own elastic force, thereby improving the assembling work thereof, as well as reducing the manufacturing cost.

Claims (2)

An inlet and an outlet are formed at a lower end of the modulator block to be fitted into the bore of the modulator block, and a magnet seat having an orifice perforated valve seat disposed in the axial direction therebetween, and installed at an outer periphery of the lower end of the magnet core, between In the solenoid valve for the anti-lock brake system having a lip seal for performing a check valve function in the and a filter member disposed in the lower portion of the magnet core to prevent foreign matter from entering the inlet side, At the bottom end of the magnet core 31a, the seal coupling portion 31e extends in a cylindrical shape so that the lip seal 35 is fitted and coupled, and extends coaxially from the seal coupling portion 31e, but the outer diameter gradually increases. A filter engaging portion 31f having a tapered surface 31g is provided, The filter member 36 is coupled to surround the filter coupling portion 31f while being elastically deformed by providing a plurality of frames 36a provided with a sieve 36b on the center and at regular intervals along the edge of the frame 36a. At the same time the upper surface (36d) is provided with a fixing piece (36c) for supporting the lower end of the lip seal 35, the solenoid valve for an anti-lock brake system. The method of claim 1, The outer circumference of the filter coupling portion 31f is provided with a recessed groove 31h concavely, A solenoid valve for an anti-lock brake system, characterized in that a locking jaw (36f) is elastically coupled to the locking groove (31h) inside the fixing piece (31c).