JP4217647B2 - Normally open solenoid valve - Google Patents

Description

  The present invention relates to a normally open solenoid valve including a valve member that opens and closes a hydraulic fluid flow path.

  Conventionally, as an electromagnetic valve (solenoid valve) that opens and closes a hydraulic fluid flow path, the valve is normally opened and an electromagnetic attraction force is generated between a fixed core and a movable core by energization of a coil to perform a valve closing operation. A normally open type solenoid valve (normally open valve) is known. Such a normally open solenoid valve includes a valve seat having a communication channel for allowing hydraulic fluid to flow into the valve, and a valve that contacts / separates the valve seat to open and close the communication channel of the valve seat. And a retainer provided with a body. In a normally open solenoid valve, the core is excited by energization of the coil, and an electromagnetic attraction force is generated between the fixed core and the movable core, whereby the movable core moves to the fixed core side and pushes the retainer. The valve body is brought into contact with the valve seat to shut off the communication fluid flow path. On the other hand, when energization of the coil is stopped, the retainer is urged toward the movable core, and the valve body is separated from the valve seat, thereby opening the communication fluid flow path.

Some normally open solenoid valves have a movable core with relief means built in (see Patent Document 1). The relief means provided in the normally open solenoid valve has a guide hole formed in the center of the movable core, a slide member that pushes the retainer toward the valve seat, and a relief spring that biases the slide member toward the retainer Is housed. In such a relief means, even when the coil is energized and the movable core is moved to the fixed core side and the valve is closed, the hydraulic pressure on the communication passage side of the valve seat rises above a predetermined pressure. When the relief spring is compressed, the retainer moves in the seating direction with respect to the valve seat together with the valve body, so that the hydraulic pressure can be relieved.
JP 2000-18416 A

  However, if fluid pressure fluctuations occur in the hydraulic fluid flow path by a pump provided in the hydraulic fluid flow path on the communication flow channel side of the valve seat repeatedly discharging the hydraulic fluid to the solenoid valve side, etc., relief occurs. The means may react sensitively and actuate to vibrate the slide member. This vibration may generate abnormal noise or generate unnecessary hydraulic fluid pulsations in the hydraulic fluid flow path. If the relief spring that biases the slide member is strengthened to prevent this, there is a concern that the relief means will not operate as set.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a normally-open electromagnetic valve that can prevent the vibration of the slide member and stabilize the operation of the relief means.

  The present invention provides a fixed core, a valve seat having a communication channel for allowing hydraulic fluid to flow in, a valve member that is slidably provided on the valve seat and opens and closes the communication channel of the valve seat, and the fixed A movable core disposed opposite to the core and capable of moving forward and backward with respect to the valve seat together with the valve member; a first elastic biasing member that biases the valve member against the valve seat in a separating direction; A coil that generates an electromagnetic attractive force between at least the fixed core and the movable core by energization, and a set load that is built in the movable core and is in contact with the valve member and larger than the first elastic biasing member The hydraulic fluid that has flowed into the communication flow path of the valve seat in a state where the valve member is pushed in the seating direction by the second elastic urging member provided in step S5 and the valve member is seated on the valve seat. When the pressure reaches a predetermined pressure, the second elastic biasing member is compressed. And a relief means having a slide member that slides in the movable core so as to separate the valve member from the valve seat. The present invention relates to a normally open solenoid valve characterized by being made of a magnetic material.

  According to the present invention, the slide member of the relief means that moves so as to move the valve member away from the valve seat is formed of the magnetic material, so that it slides using the magnetism generated from the coil in the closed state. The member can be slid while being attracted to the movable core. That is, in the present invention, by increasing the sliding resistance of the slide member during the relief operation, the movement of the slide member is slowed down, and the relief means reacts sensitively to the hydraulic pressure fluctuation of the hydraulic fluid, causing the slide member to vibrate. Can be prevented. As a result, in the normally open solenoid valve of the present invention, the hydraulic fluid pressure stabilization control is performed without generating abnormal noise in the relief operation or causing unnecessary hydraulic fluid pulsation in the hydraulic fluid flow path. It can be performed.

  In the normally open solenoid valve of the present invention, the movable core has a cylindrical guide region that guides the sliding of the slide member, and the slide member is a cylindrical slide that is guided by the guide region. It is preferable that the outer diameter of the sliding portion is smaller than the inner diameter of the guide region. In this way, since the area where the slide member is attracted to the movable core is only a small area along the sliding direction of the slide member, the relief operation can be surely performed even if the sliding resistance is increased. it can.

  In the normally open solenoid valve according to the present invention, the slide member may be formed in a cylindrical shape with a bottom so that at least a part of the second elastic urging member can be accommodated therein. In this way, the weight can be reduced, and it is not necessary to provide a separate space for accommodating the second elastic biasing member, so that the entire solenoid valve can be reduced in size, and further, the electromagnetic The degree of freedom of design inside the valve can be improved.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the drawings.

  FIG. 1 is a longitudinal cross-sectional view showing an example of a valve open state of a normally open solenoid valve 10 according to the present embodiment. FIG. 2 is a longitudinal sectional view showing an example of a closed state of the normally open solenoid valve 10 according to the present embodiment. FIG. 3 is a longitudinal sectional view showing an example of a relief state of the normally open solenoid valve 10 according to the present embodiment. FIG. 4 is a partially enlarged view of FIG. FIG. 5 is a cross-sectional view of FIG.

  The normally open solenoid valve 10 according to the present embodiment is for opening and closing a hydraulic fluid passage of a vehicle brake fluid pressure control device, for example. A part of the normally open solenoid valve 10 is inserted into a mounting hole 3 formed in a base 1 made of aluminum, for example, and is fixed by an annular locking member 4. The normally-open electromagnetic valve 10 is accommodated in a fixed core 20 fixed to the base 1, a valve seat 60 that forms an opening for a flow path of hydraulic fluid, and a valve hole 22 that penetrates from one end of the fixed core 20 to the other end. Retainer 30 and valve body 50 as valve members to be operated, a seat spring 52 (first elastic biasing member) that biases the valve body 50 in the seating direction with respect to the valve seat 60, and the fixed core 20. And a movable core 40 that moves forward while pushing the retainer 30 and the valve body 50 against the valve seat 60. Further, the normally open solenoid valve 10 includes a coil 12 that energizes the fixed core 20 by energization to advance the movable core 40 in the seating direction of the valve body 50 and the movable core 40, and pushes the retainer 30 in the seating direction. And a relief means 43 that moves.

  The fixed core 20 is a substantially cylindrical member formed of a magnetic material such as iron or an iron alloy. The fixed core 20 has a first opening 24 and a second opening 26 that open to the hydraulic fluid channel 2 formed in the base 1. On the first opening 24 side of the fixed core 20, an annular seal member C <b> 2 made of a rubber composition is disposed between the base 1 and the working fluid flow path on the first opening 24 side and the second opening 26 side. 2 is liquid-tightly sealed. An annular seal member C1 made of a rubber composition is disposed between the fixed core 20 and the base 1 at the second opening 26 side. The outside is liquid-tightly sealed. A first filter member F <b> 1 is attached to the first opening 24 of the fixed core 20. A cylindrical valve seat 60 is fitted and fixed to the first opening 24 side which is one opening end of the valve hole 22 of the fixed core 20.

  The opening side of the bottomed cylindrical guide tube 18 is welded and fixed to the fixed core 20 protruding from the upper surface of the base 1, and the coil 12 wound around the resin bobbin 14 and the outside of the coil 12 are connected. A covering coil case 16 is attached. The guide cylinder 18 has a thin cylindrical portion having an inner diameter substantially the same as the outer peripheral surface of the fixed core 20 and a hemispherical bottom portion that closes an end portion of the cylindrical portion. The opening-side inner peripheral surface of the upper portion of the guide tube 18 is welded and fixed to the outer peripheral surface of the fixed core 20. A movable core 40 is built in the guide cylinder 18, and the movable core 40 is slidably guided on the inner peripheral surface of the cylindrical portion, and is retracted by contacting the inner surface of the bottom portion.

  The coil 12 is electrically connected to current control means (not shown) through a terminal 13. The current control unit selectively controls the energization of an arbitrary current value to the coil 12 according to the use state of the brake fluid pressure control device.

  The movable core 40 has a substantially cylindrical shape made of a magnetic material such as an iron-based metal, and a plurality of, for example, three communication grooves 41 extending along the longitudinal axis direction are formed on the outer peripheral surface. The hydraulic fluid can be circulated by communicating with 22. The movable core 40 is spaced apart from the fixed core 20 in a non-energized state of the coil 12, and is moved forward by being attracted to the fixed core 20 side in the energized state of the coil 12. A guide hole 42 penetrating in the axial direction is formed in the movable core 40, and a relief means 43 is provided in the guide hole 42.

  The relief means 43 is a bottomed cylindrical shape that is press-fitted and fixed to a rear end portion (upper end portion in FIG. 1) of the guide hole 42 that is slidably guided in the guide region 42a in the guide hole 42 and can be moved forward and backward. And a relief spring 44 (second elastic biasing member) disposed between the contact member 48 and the receiving member 47. The slide member 48 of the relief means 43 abuts on the end of the retainer 30 and pushes the retainer 30 by the movable core 40 being attracted and moved forward by energizing the coil 12. The relief spring 44 is contracted so that the set load is larger than the seat spring 52 that urges the valve body 50 away from the valve seat 60 in the separating direction. Therefore, when the coil 12 is energized and the movable core 40 is attracted to the fixed core 20, the seat spring 52 is compressed earlier than the relief spring 44, and the valve body 50 is seated on the valve seat 60.

  As shown in FIG. 4, the slide member 48 has a thin bottomed cylindrical shape, a contact portion 481 that contacts the retainer 30, a slide portion 482 that is guided by the guide region 42 a of the guide hole 42, and a contact portion A step portion 484 connected from the portion 481 to the sliding portion 482, and is formed so that at least a part of the relief spring 44 can be accommodated therein. One end of the relief spring 44 comes into contact with the inner side surface of the step portion 484, and the outer surface of the step portion 484 comes into contact with a stopper step portion 462 formed to protrude inside the guide hole 42 of the movable core 40. 48 advance limits are defined. The contact portion 481 has a bottom portion 483 formed on a flat surface, and contacts the end surface 36 of the retainer 30. The hydraulic fluid is formed between the slide member 48 and the guide hole 42 so that the hydraulic fluid can flow therethrough, and the hydraulic fluid can also flow through the relief means 43 by the communication hole 49 formed on the side surface of the sliding portion 482. ing. Thus, if it forms so that the relief spring 44 may be accommodated in the inside of the slide member 48, weight reduction can be achieved. In addition, since it is not necessary to provide a space for accommodating the relief spring 44, the entire solenoid valve can be reduced in size, and the degree of freedom in designing the solenoid valve can be improved.

  The retainer 30 has a substantially cylindrical shape, and is slidably guided by a valve hole 22 penetrating along the axial direction of the fixed core 20 so as to freely advance and retract. A spherical valve body 50 is press-fitted and fixed at the tip of the retainer 30, and an end surface 36 with which the slide member 48 of the movable core 40 abuts is formed at the other end. A plurality of flow grooves 32 are formed on the outer peripheral wall surface of the retainer 30 to allow the working fluid to flow. The retainer 30 abuts against the seat spring 52 and is biased toward the valve seat 60 in the separating direction.

  The valve seat 60 has a substantially cylindrical shape and includes a first valve seat opening 62 having a small diameter and a second valve seat opening 64 having a large diameter, and the second valve seat extends from the first valve seat opening 62. A communication channel that penetrates the opening 64 in the axial direction is provided. The valve seat 60 is fitted and fixed to the first opening 24 side of the valve hole 22 of the fixed core 20, and the second valve seat opening 64 opens to the first opening 24 of the fixed core 20. A seat 66 for seating the valve body 50 is formed in the first valve seat opening 62 of the valve seat 60. The seating portion 66 is formed by a tapered surface whose diameter increases toward the outside of the valve seat 60, and closes the first valve seat opening 62 by closing the valve body 50.

  Hereinafter, the operation of the normally open solenoid valve 10 according to the present embodiment will be described. The normally open solenoid valve 10 can take at least three operation states, ie, a valve open state shown in FIG. 1, a valve closed state shown in FIG. 2, and a relief state shown in FIG.

  FIG. 1 shows a valve-open state of the normally-open electromagnetic valve 10. In a state where no current is supplied to the coil 12, the retainer 30 and the valve body 50, which are valve members, are separated from the valve seat 66 by the seat spring 52. Therefore, in this state, the valve is always open, and the working fluid flows from the first opening 24 to the second opening 26 through the first valve seat opening 62. At this time, the retainer 30 is biased toward the movable core 40 by the spring force of the seat spring 52. Although the slide member 48 of the relief means is in contact with the end face 36 of the retainer 30, the set load of the seat spring 52 is smaller than the set load of the relief spring 44, so the relief spring 44 is not compressed. Therefore, the retainer 30 pushes up the movable core 40 while the step 484 of the contact member 48 is in contact with the stopper step 462 of the guide hole 42, and the end of the movable core 40 is placed on the inner surface of the bottom of the guide tube 18. It is held at the pushed back limit.

  FIG. 2 shows an example of the closed state of the normally open solenoid valve 10. When energization of the coil 12 is started from the valve-opened state shown in FIG. 1, the movable core 40 is attracted to the fixed core 20 side by the magnetic attraction force, and advances toward the fixed core 20 side while compressing the seat spring 52. This attractive force is a force that attracts each other by the magnetic flux between the end face 28 of the fixed core 20 on the movable core 40 side and the facing portion 46 of the movable core 40 that faces the end face 28. When the movable core 40 is sucked, the slide member 48 that is in contact with the end surface 36 of the retainer 30 pushes the retainer 30. The suction force generated between the fixed core 20 and the movable core 40 exceeds the spring force of the seat spring 52, and the valve body 50 is seated on the valve seat 66 and closes the flow path of the first opening 26.

  At this time, when the hydraulic fluid flows into the communication flow path from the second valve seat opening 64 to the first valve seat opening 62 at a fluid pressure equal to or higher than a predetermined relief pressure, the retainer 30 is moved as shown in FIG. By pushing the relief means 43, the valve body 50 is separated from the valve seat 60 and opened to relieve the hydraulic fluid. In the relief means 43, the relief spring 44 is compressed by receiving a pushing force from the retainer 30, so that the slide member 48 moves backward while sliding in the guide hole 42 of the movable core 40. In the present embodiment, the relief pressure of the relief means 43 is determined by the compression amount of the relief spring 44 in the valve closed state.

  With respect to such a relief operation, the pump provided in the hydraulic fluid channel on the communication channel side of the valve seat 60 repeatedly performs the operation of discharging the hydraulic fluid to the normally open solenoid valve 10 side, etc. When fluid pressure fluctuations occur in the path, the relief means 43 may react with sensitivity and operate to vibrate the slide member 48. This vibration may generate abnormal noise or generate unnecessary hydraulic fluid pulsations in the hydraulic fluid flow path.

  Therefore, in the present embodiment, the slide member 48 is formed of a magnetic material such as iron or an iron alloy. Accordingly, when the valve closing state shown in FIG. 2 is shifted to the relief state shown in FIG. 3, the slide member 48 is guided while being attracted to the guide region 42 a of the movable core 40 using the magnetism generated by energization of the coil 12. It can be slid in the hole 42. In other words, in this embodiment, the sliding resistance of the slide member 48 is increased during the relief operation, thereby slowing the movement of the slide member 48, and the relief means 43 reacts sensitively to the hydraulic pressure fluctuation and slides. The situation where the member 48 vibrates can be prevented. As a result, the normally open solenoid valve 10 performs stabilization control of the hydraulic pressure of the hydraulic fluid without generating abnormal noise in the relief operation or causing unnecessary hydraulic fluid pulsation in the hydraulic fluid flow path. be able to.

  Further, in the present embodiment, as shown in the sectional view of FIG. 5, the movable core 40 has a cylindrical guide region 42a in the guide hole 42 that guides the sliding of the slide member 48, and the slide member 48 has a cylindrical sliding portion 482 guided by the guide region 42a, and is provided such that the outer diameter d1 of the sliding portion 482 is smaller than the inner diameter d2 of the guide region 42a. In this way, the area where the sliding portion 482 of the slide member 48 is attracted to the guide area 42a of the movable core 40 is limited to the vicinity of the contact 420 on the circumference, so the slide member 48 is formed of a magnetic material. Even if the sliding resistance is increased, the relief operation can be surely performed.

  In addition, this invention is not limited to this Embodiment, It can deform | transform into various forms within the range of the summary of this invention. For example, the relief spring 44 may be constituted by another elastic member instead of the spring. Further, for example, the slide member 48 is formed in a bottomed cylindrical shape, but may be formed in a block shape.

It is sectional drawing which shows the valve opening state of the normally open solenoid valve which concerns on this Embodiment. It is sectional drawing which shows the valve closing state of the normally open solenoid valve which concerns on this Embodiment. It is sectional drawing which shows the relief state of the normally open type solenoid valve which concerns on this Embodiment. FIG. 3 is an enlarged cross-sectional view of the vicinity of an end portion of a movable core in FIG. 2. It is sectional drawing regarding the VV line | wire of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Normally open type solenoid valve, 12 coils, 20 fixed core, 30 retainer, 40 movable core, 42 guide hole, 42a guide area | region, 43 relief means, 44 relief spring (2nd elastic urging member) 48 slide member, 481 Abutting portion, 482 sliding portion, 50 valve body, 52 seat spring (first elastic biasing member), 60 valve seat,

Claims (3)

A fixed core;
A valve seat having a communication channel for flowing hydraulic fluid;
A valve member provided so as to be seated on the valve seat, and opening and closing a communication flow path of the valve seat;
A movable core disposed opposite to the fixed core and capable of moving forward and backward with respect to the valve seat together with the valve member;
A first elastic biasing member that biases the valve member in a separating direction with respect to the valve seat;
A coil that generates an electromagnetic attractive force between at least the fixed core and the movable core by energization;
Built in the movable core, abuts on the valve member and pushes the valve member in the seating direction by a second elastic biasing member provided with a larger set load than the first elastic biasing member, The second elastic biasing member is compressed when the hydraulic pressure of the hydraulic fluid flowing into the communication flow path of the valve seat reaches a predetermined pressure with the valve member seated on the valve seat. A relief means having a slide member that slides in the movable core so as to separate the valve member from the valve seat.
In a normally open solenoid valve with
The normally open solenoid valve characterized in that the slide member is formed of a magnetic material. In claim 1,
The movable core has a cylindrical guide region that guides sliding of the slide member,
The normally open solenoid valve characterized in that the slide member has a cylindrical sliding portion guided by the guide region, and an outer diameter of the sliding portion is smaller than an inner diameter of the guide region. In claim 1 or 2,
The normally open solenoid valve characterized in that the slide member has a bottomed cylindrical shape, and is formed so as to accommodate at least a part of the second elastic biasing member.

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