KR100423643B1 - 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 effectively reduce noise generated by an increase in hydraulic pressure transmitted to an hydraulic brake side through an orifice during orifice opening operation according to ABS control.

According to the normally open solenoid valve 30 for an anti-lock brake system which concerns on this invention, the hydraulic pressure which escaped between the orifice 31e and the valve surface 33c to the lower end of the plunger 33b turns to the valve seat 31e side. Hydraulic guide means 34 and 35 for guiding the outlet 31c toward the outlet 31 are provided so that the pressure pulsation of the hydraulic pressure per unit pulse is reduced and transmitted stably, and can effectively prevent the occurrence of noise due to the hydraulic control. There is an advantage.

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, the vehicle is equipped with a hydraulic brake for braking the front wheel and the rear wheel, a hydraulic power unit for forming and transmitting the braking hydraulic pressure to the hydraulic brake side, and a master cylinder, so that the braking hydraulic pressure is formed when the driver presses the brake pedal. To generate 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 transmitted to the hydraulic brake side. With a pump.

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) has an inlet 1b and an outlet 1c formed therebetween, and a valve seat 1e having a perforated orifice 1d therebetween is formed. A valve assembly (1) disposed in the axial direction and the coil assembly (2) consisting of a kind of solenoid is wound around the coil (2a) to form a magnetic force upon application of current.

The valve assembly 1 includes a magnet core 1a having a lower end compactly mounted on an aluminum modulator block 4, and the magnet core 1a moves forward and backward by magnetic force to open and operate the orifice 1d. The valve device 3 is installed.

The lower end of the magnet core (1a) is processed in the axial direction inlet (1b) is associated with the hydraulic line of the master cylinder side, the outlet (1c) is processed on the magnet core side side of the hydraulic brake (not shown) It is associated with the inlet of the wheel cylinder side and the normally closed solenoid valve (not shown).

In addition, the valve device 3 has a cylindrical sleeve 3a which is press-fitted to the upper end of the magnet core 1a exposed to the outside of the modulator block 4, and is capable of moving forward and backward in the sleeve 3a. Armature (3b, armature).

The armature 3b is installed to be accommodated in the coil assembly 2, and is provided with a plunger 3c extending in a rod shape at the lower end and having a sphere 3d at the lower end. The plunger 3c is slidably disposed in the magnet core 1a in the axial direction together with the armature 3b, so that the sphere 3d opens and closes the orifice 1d of the valve seat 1e.

In addition, a coil spring type return spring 3e is disposed between the lower end of the plunger 3c and the orifice 1d for the return of the armature 3b. As a result, the sphere 3d of the plunger 3c is normally maintained in the open state of the orifice 1d by the elastic support force of the return spring 3e. (In the case of a normally closed solenoid valve, the sphere of the plunger will normally keep the orifice closed.)

In the anti-lock brake system equipped with the NO type solenoid valve configured as described above, when the vehicle is locked due to excessive pressure from the master cylinder to the hydraulic brake side during ABS operation, the ECU locks the NO type solenoid valve. Power is applied to the assembly 2 to block the flow path of the master cylinder side and the hydraulic brake.

That is, when power is applied to the coil assembly 2, a magnetic field is formed in the periphery of the coil assembly 2, whereby the armature 3b and the plunger 3c overcome the elastic force of the return spring 3e, That is, it is pulled to the magnet core 1a side. At this time, as the plunger 3c is lowered integrally with the armature 3b, the sphere 3d is seated on the upper part of the orifice 1d and the orifice 1d is closed, so that the braking hydraulic pressure generated by the master cylinder or the pump is applied to the hydraulic brake. Delivery to the side is blocked.

The power supply is cut off when additional hydraulic pressure is required to the hydraulic brake side under control of ECU during braking. At this time, the armature 3b rises upward with the plunger 3c by the elastic restoring force of the return spring 3e, whereby the sphere 3d of the plunger 3c opens the orifice 1d again. When braking hydraulic pressure is transmitted from the cylinder side, it is transmitted to the hydraulic brake side through the orifice 1d.

However, in the conventional NO type solenoid valve, considerable noise is generated due to repeated operations such as opening, closing, opening, closing, etc. during the ABS control. In particular, upon opening the orifice 1d according to the ABS control, as soon as a short clearance G1 between the orifice 1d and the sphere 3d is passed, the flow path expands and the hydraulic pressure suddenly exits to the outlet 1c side. Accordingly, the pressure pulsation peak of the oil remains, which acts as a cause of the operation noise of the anti-lock brake system, and the pressure pulsation is transmitted to the brake pedal side through the master cylinder, thereby causing anxiety to the driver.

The present invention is to solve such a problem, an object of the present invention is to configure the flow path so that the hydraulic pressure exiting it at the opening of the orifice exits by rotating the side of the valve seat, while reducing the pressure pulsation of the hydraulic pressure per unit pulse It is to provide a normally open solenoid valve for an anti-lock brake system that can be stably transmitted and effectively prevent noise generation due to hydraulic control.

1 is a cross-sectional view showing the internal configuration of a conventional normal open solenoid valve used in an anti-lock brake system.

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

Figure 3 is a cross-sectional view showing a normal open solenoid valve according to an embodiment of the present invention.

Figure 4 is a cross-sectional view showing a normal open solenoid valve according to another embodiment of 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 31d .. Valve seat

31f. Sleeve 32. Coil Assembly

33. Valve device 33a.

33b..plunger 33d..return spring

34. Skirt 35. Guide

The present invention for achieving this object,

A valve seat having an inlet and an outlet formed at one end thereof and a perforated orifice therebetween, and a magnet core having a conventional sleeve mounted at the other end thereof, a coil assembly installed to surround the sleeve to form a magnetic field when power is applied, and a sleeve The armature which is built in to be able to move up and down but descends when the power is supplied to the coil assembly, and the magnet core is arranged in the axial direction to interlock with the armature to open and close the orifice. In a normally open solenoid valve for an anti-lock brake system with a return spring disposed between the plunger and the valve seat to return,

The lower portion of the plunger is characterized in that the hydraulic pressure guide means for guiding the hydraulic pressure exited between the orifice and the valve surface to exit to the outlet side while rotating the valve seat side.

In addition, the hydraulic pressure guide means is characterized in that it comprises a cylindrical skirt integrally formed on the lower end of the plunger so as to surround the side of the valve seat to maintain a constant interval.

In addition, the hydraulic guide means is provided with a cylindrical guide tube, one end of which is fixed to the bottom of the plunger and the other end to surround the side of the valve seat to maintain a constant interval, characterized in that the return to one end of the guide tube An outward flange portion for supporting the end of the spring is provided.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. 2 is a hydraulic system diagram of the anti-lock brake system to which the present invention is applied, and FIG. 3 shows the internal structure 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.

Referring to FIG. 3, the NO type solenoid valve 30 according to the present invention is coupled to the modulator block 80 and has a valve assembly 31 in which a valve device 33 is built, and forms a magnetic force when a power is applied to the valve device. A coil assembly 32 for operating 33 is provided.

First, 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 31f to be described later. When the power is applied under the control of the ECU, the valve device 33 To create a magnetic force to actuate

In addition, the valve assembly 31 is press-fitted to the bore 81 processed at the lower end of the modulated block 80, and the inlet 31b processed in the axial direction so as to be associated with the master cylinder 11 (see FIG. 2). It is coaxially press-fitted inside the inlet 31b with the magnet core 31a having the outlet 31c machined radially on the side to be connected to the inlet side of the hydraulic brake 20 and the NC type solenoid valve 40. It consists of a valve seat 31d having an orifice 31e drilled in the axial direction, a cylindrical sleeve 31f coupled to an upper end of the magnet core 31a protruding out of the modulator block 80, and the like. Reference numeral "31g" is a ball type check valve provided on the outer periphery of the lower end of the magnet core 31a, and "31h" is a filter member for compactly disposed at the bottom of the inlet 31b to prevent foreign substances from entering.

In addition, the valve device 33 has an armature 33a which moves up and down by interacting with a magnetic force inside the sleeve 31f, and extends in a rod shape at the lower end of the armature 33a, and has a hemispherical valve face 33c at its tip. The plunger 33b is provided. The plunger 33b is arranged to be able to move up and down by loosely penetrating the inside of the magnet core 33a in the axial direction. At this time, the valve surface 33c is normally positioned directly above the valve seat 31d so as to be spaced apart at regular intervals so that the orifice 31e is kept open. For this purpose, the lower end of the plunger 33b and the valve seat 31d are provided. Between the upper part, the return spring 33d which elastically supports the plunger 33b upwards is provided. This return spring 33d is composed of a kind of coil spring. Reference numeral 33e denotes a grove formed on the outer circumferential surface of the armature 33a in an axial direction, and thus, all the oil is filled in the sleeve 31f.

On the other hand, the plunger 33b of the valve device 33 is stably transmitted while reducing the pressure pulsation of the hydraulic pressure, and escaped between the orifice 31e and the valve surface 33c to effectively prevent noise generation due to the hydraulic pressure control. A hydraulic pressure guiding means for guiding the hydraulic pressure to exit the upper side of the valve seat 31d toward the outlet 31c is provided.

The hydraulic guide means is composed of a skirt portion 34 integrally formed on the lower edge portion of the plunger 33b, which is provided in a tubular shape so as to surround the upper side of the valve seat 31d so as to maintain a constant interval. As a result, the hydraulic pressure which has escaped the clearance between the orifice 31e and the valve face 33c continues to pass between the inner surface of the skirt portion 34 and the upper surface of the valve seat 31d and exits to the outlet 31c side.

As a result, since the hydraulic flow path is configured to be much longer than the conventional one, the hydraulic pressure is discharged to the outlet 31c side while the pressure pulsation is removed, which will be described in detail in the following operation effects. At this time, the clearance between the inner surface of the skirt portion 34 and the upper surface of the valve seat 31d is preferably configured to remain constant throughout.

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 is transmitted to the hydraulic brake 20 side through the inlet 31b → orifice 31e → outlet 31c and the braking action is performed. Is done. 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 31e 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.

Thus, during the ABS control, the NO-type solenoid valve 30 according to the present invention, the opening and closing of the orifice 31e according to the lifting and lowering movement of the valve device 33. .. closing.

At this time, when the orifice 31e is opened by lifting the valve device 33, the hydraulic pressure passes between the upper side of the valve seat 31d and the inner surface of the skirt portion 34, that is, the direction of the arrow shown in FIG. Accordingly, it exits to the outlet 31c side, and as it passes through a long flow path, the pressure pulsation peak per unit pulse is completely removed and transmitted stably, and noise generation due to hydraulic control is significantly reduced.

In addition, as the hydraulic pressure exiting the orifice 31e exits the inner surface of the skirt portion 34 and the upper surface of the valve seat 31d toward the outlet 31c, the inner surface of the skirt portion 34 moves downward. Under pressure, the orifice 31e is slowly opened. That is, since the return of the plunger 33b and the armature 33a progresses gradually compared with the past, the noise by the friction of the armature 33a and the upper part of the sleeve 31f is reduced remarkably.

On the other hand, this technical idea is not limited to this, as shown in Figure 4, even if the hydraulic guide means consisting of a guide pipe 35 that is press-fitted to the bottom of the plunger 33b can achieve the desired purpose of the present invention. .

That is, the guide tube 35 is configured in a cylindrical shape to accommodate the upper end is tightly fixed to the lower end of the plunger (33b) to surround the upper side of the valve seat (31e) to maintain a constant interval. Further, an outward flange portion 35a for supporting the upper end of the return spring 33d is provided at the upper end of the guide tube 35.

Therefore, when the NO type solenoid valve 30 is closed and the power supply is cut off, the armature 33a is raised again together with the plunger 33b by the elastic restoring force of the return spring 33d, and the orifice 31e is opened. At this time, the hydraulic pressure exiting the orifice 31e is transmitted to the outlet 31c while rotating between the inner surface of the guide tube 35 and the upper surface of the valve seat 31e.

Because of this, since the hydraulic pressure passes through the passage formed long between the guide tube 35 and the upper surface of the valve seat 31e, the pressure pulsation peak is completely removed, and the hydraulic pressure is stably transmitted to the hydraulic brake 20 side. Noise generation is significantly reduced.

As described in detail above, according to the normally open solenoid valve for an anti-lock brake system according to the present invention, the hydraulic pressure that escapes between the orifice and the valve surface at the lower end of the plunger is guided to the outlet side while turning the valve seat side. Since the hydraulic pressure guide means is provided, the pressure pulsation of the hydraulic pressure per unit pulse is stably transmitted and has an advantage of effectively preventing the generation of noise due to the hydraulic pressure control.

Claims (4)

A magnet seat having an inlet and an outlet formed at one end thereof and having a perforated orifice therebetween, and a magnet core having a conventional sleeve mounted at the other end thereof, and a coil assembly installed to surround the sleeve to form a magnetic field when power is applied; A plunger which is built in the sleeve so as to move up and down and descends when power is applied to the coil assembly, and the magnet core penetrates in the axial direction to interlock with the armature and open and close the orifice. And, in the normally open solenoid valve for an anti-lock brake system having a return spring disposed between the plunger and the valve seat to return the armature and the plunger, Hydraulic pressure guide means for guiding the hydraulic pressure exited between the orifice (31e) and the valve surface (33c) exits the side of the valve seat (31e) toward the outlet (31c) at the lower end of the plunger (33b) Normally open solenoid valve for an anti-lock brake system, characterized in that provided. The method of claim 1, The hydraulic guide means has an anti-lock brake, characterized in that it comprises a cylindrical skirt portion 34 formed integrally with the lower end of the plunger 33b so as to surround the side of the valve seat 31e so as to maintain a constant interval. Normally open solenoid valve for system. The method of claim 1, The hydraulic guide means is provided with a cylindrical guide tube 35, one end of which is secured to the lower end of the plunger (33b) and the other end to surround the side of the valve seat (31e) to maintain a constant interval. A normally open solenoid valve for an anti-lock brake system. The method of claim 3, An open flange solenoid valve for an anti-lock brake system, characterized in that an outward flange portion 35a is provided at one end of the guide tube 35 to support an end of the return spring 33d.