CROSS-REFERENCE TO RELATED APPLICATION

This application is based on and claims priority under 35 U.S.C. § 119 to Korean Patent Applications No. 2017-0100096, filed on Aug. 8, 2017, and No. 2017-0115825, filed on Sep. 11, 2017 in the Korean Intellectual Property Office, the disclosures of which are incorporated herein by reference.

BACKGROUND

1. Field

The present disclosure relates to a solenoid valve used in a brake system that generates a braking force using an electrical signal corresponding to a displacement of a brake pedal.

2. Description of the Related Art

Vehicles are provided with a hydraulic brake system for braking. Recently, various types of hydraulic brake systems have been proposed for obtaining more powerful and stable braking force. Examples of the hydraulic brake system include an anti-lock brake system (ABS) that prevents wheel skidding during braking, a brake traction control system (BTCS) that prevents slip of driving wheels during sudden start or sudden acceleration of the vehicle, and an electronic stability system (ESC) that stably maintains a driving condition of the vehicle by controlling brake hydraulic pressure using a combination of the ABS and the BTCS.

On the other hand, the ESC requires a certain level of transfer of fluid in a brake apply and a brake release, and in order to implement such a system, a plurality of electronically-controlled solenoid valves are installed in a modulator block.

A solenoid valve used in the above-described brake system includes a hollow valve housing that is insertedly installed in a bore of a modulator block and has an inlet port and an outlet port communicating with the modulator block, a hollow cylindrical valve housing that is inserted from the top of the valve housing and welded to the valve housing, a valve seat that is press-fitted to the inside of the valve housing and provided with an orifice, a magnetic core welded to the sleeve at a side opposite the valve housing, and an armature reciprocatingly installed in the sleeve.

RELATED ART DOCUMENT

Patent Document

(Patent Document 0001) Korean Registered Patent No. 10-1276072 (Jun. 18, 2013)

SUMMARY

Therefore, it is an object of the present disclosure to provide a solenoid valve for a brake system having a reduced noise, vibration, and harshness (NVH).

Additional aspects of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Therefore, it is an aspect of the present disclosure to provide a solenoid valve for a brake system controlling a flow rate of a flow path connecting a first port to a second port, the solenoid valve including: a valve housing installed in a modulator block; an armature disposed inside the valve housing and reciprocating in an axial direction to adjust a flow rate of a working fluid; a first elastic member configured to provide the armature with an elastic force; a magnet core configured to provide the armature with a driving force in a direction opposed to the elastic force provided by the first elastic member; and a damper part interposed between the magnet core and the armature.

The solenoid valve may further include: a sleeve configured to guide an ascent and a descent of the armature, and engaged with the magnet core at an upper side thereof and engaged with the valve housing at a lower side thereof; and a filter member installed at an outer surface of the valve housing and provided with a mesh part at a surface facing the first port, wherein the first elastic member may be installed to have one end making contact with the armature and the other end making contact with the damper part.

The solenoid valve may further include: a sleeve configured to guide an ascent and a descent of the armature, and engaged with the magnet core at an upper side thereof and engaged with the valve housing at a lower side thereof; a first valve seat located at a lower side of the armature and having an orifice that is opened and closed by the armature; a second elastic member configured to provide the first valve seat with an elastic force; and a second valve seat fixed to the valve housing and having a flow path that is opened and closed by an ascent and a descent of the first valve seat, wherein the first elastic member may have opposite ends thereof making contact with the magnet core and the damper part, respectively.

The damper part may include: a restriction part inserted into a rectangular groove of the armature; a protrusion part provided at a side facing the magnet core; and an engagement part configured to restrict the first elastic member.

The first elastic member may be integrally formed with the damper part.

The first elastic member may include: a wrinkle part configured to generate an elastic force with a restoring force against contraction or expansion; and a protrusion part protruding from an outer surface of the wrinkle part to restrict a width direction movement of the first elastic member.

The solenoid valve may further include: a sleeve configured to guide an ascent and a descent of the armature, and engaged with the magnet core at an upper side thereof and engaged with the valve housing at a lower side thereof; and a filter member installed at the valve housing to surround the second port, wherein the first elastic member may have one end thereof making contact with the armature and the other end thereof making contact with the magnet core.

The solenoid valve may further include: a sleeve configured to guide an ascent and a descent of the armature, and engaged with the magnet core at an upper side thereof and engaged with the valve housing at a lower side thereof; a first valve seat located at a lower side of the armature and provided with an orifice that is opened and closed by the armature; a second elastic member providing the first valve seat with an elastic force; and a second valve seat fixed to the valve housing and having a flow path that is opened and closed by an ascent and a descent of the first valve seat, wherein the first elastic member may be installed to have one end thereof making contact with the armature and the other end thereof making contact with the magnet core.

The solenoid valve may further include: a lip seal engaged with the valve housing and provided with an inclined protrusion part that is deformed by a difference in pressure such that transfer of a fluid is allowed only in one direction, wherein the flow path may include: a first flow path that is opened and closed by an ascent and a descent of the armature; and a second flow path formed by deformation of the inclined protrusion part.

