JP2006189140A - Solenoid valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solenoid valve in which seizure of a plunger and any other malfunctions such as sliding troubles are not caused, normal valve-opening/closing operations are ensured for a long period of time, and an impulsive sound produced at the time of actuation is effectively reduced. <P>SOLUTION: A movable member 32 is axially movably provided at the end of an attraction piece 27 with a shock-absorbing member 35 made of a gummy elastic material placed in between so that the plunger 22 is brought into contact with the movable member 32. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electromagnetic valve, and more particularly, to an electromagnetic valve that is provided with a measure for reducing the impact shock noise between an attractor and a plunger.

  In the solenoid valve, when the on-off valve is operated, the plunger is magnetically attracted to the attractor, so that the attractor and the plunger collide to generate an impact sound (operation sound). This impact sound becomes annoying noise for people around the device in electromagnetic valves used in automobiles, medical devices, room air conditioners and the like.

  In order to attenuate the impact sound at the time of this operation, a buffer material is put between the suction element and the plunger (for example, Patent Document 1).

  When rubber is used as the cushioning material, the cushioning material will stick (adsorb) to the plunger, and the phenomenon that the valve does not operate in the valve closing direction with only the return spring force (plunger sticking) or the operation delay phenomenon will occur. It has been known.

  In order to eliminate this rubber sticking, it is also considered to use a resin such as a tetrafluoroethylene resin as a buffer material. However, since the resin has a higher hardness than rubber and does not have sufficient elasticity, a sufficient silencing effect cannot be expected.

  Further, as a structure that draws out the characteristics of the rubber cushioning material without causing rubber sticking, a laminated structure in which a resin plate is superimposed on the surface of the rubber plate on which the plunger collides has been devised (for example, Patent Document 2).

  However, depending on the use conditions of the solenoid valve, the buffer material stacked under the influence of fluid and temperature may swell and expand and deform, obstructing the movement path of the plunger and hindering the operation of the plunger. In addition, when the resin plate is laminated on the rubber plate, the plunger is separated from the attractor by the thickness of the resin plate in order to ensure the same lift length of the plunger. As a result, the power consumption of the electromagnetic coil required for magnetically attracting the plunger increases.

  Moreover, there exists an electromagnetic valve which reduces an impact force with the bending of a shock absorbing material through the shock absorbing action rod which consists of magnetic bodies (for example, patent document 3).

  However, the following matters are mentioned as disadvantages of this solenoid valve.

(1) Since the structure is such that the buffer operating rod is pressed and locked to the suction element or the plunger, the processing and assembly costs are increased.

(2) Since the buffer actuating rod, which is a magnetic body, slides within an attractor or plunger, which is a magnetic body, when wear powder is generated, it is magnetized and cannot be removed, thus promoting wear. The magnetized wear powder becomes a sliding resistance and causes a delay in the opening / closing time of the solenoid valve.

(3) When the number of operations increases, magnetized wear powder may adhere to the periphery of the plunger adsorption surface, and the valve closing operation may not be performed normally.
Japanese Utility Model Publication No. 3-24946 Japanese Patent No. 2670476 Japanese Utility Model Publication No. 56-104675

  The problem to be solved by the present invention is to effectively reduce the impact noise generated during operation by guaranteeing normal on-off valve operation over a long period of time without causing problems such as plunger sticking and sliding trouble. That is.

  An electromagnetic valve according to the present invention includes an electromagnetic coil, a fixedly arranged attractor that generates a magnetic attractive force by excitation of the electromagnetic coil, a plunger that is magnetically attracted to the attractor and moves in an axial direction, and the plunger. In the electromagnetic valve having a valve body that opens and closes by movement of the plunger in the axial direction and a separation spring that biases the plunger in a direction to separate the plunger from the attractor, either the attractor or the plunger, A movable member is provided so as to be movable in the axial direction across a rubber-made elastic cushioning member, and when the plunger is magnetically attracted by the attractor, either the attractor or the plunger contacts the movable member. Touch.

  In the electromagnetic valve according to the present invention, preferably, a bottomed receiving hole is formed in one of the attractor and the plunger, and the movable member is slidably fitted in the receiving hole so as to be slidable in the axial direction. The buffer member is disposed between the bottom of the receiving hole and the movable member.

  In the electromagnetic valve according to the present invention, preferably, a non-contact magnetic attraction surface for the other of the attraction element and the plunger is formed on the periphery of the receiving hole, and the movable member is made of a non-magnetic material. .

  In the electromagnetic valve according to the present invention, preferably, the buffer member is attached to the movable member in a state where a maximum compression allowance is defined.

  The electromagnetic valve according to the present invention is preferably configured such that one of the springs of the separation spring is in contact with a portion of the movable member where the other of the plunger and the plunger abuts when the plunger is magnetically attracted by the attractor. A seat is formed.

  In the electromagnetic valve according to the present invention, when the plunger is magnetically attracted to the attractor by the excitation of the electromagnetic coil, and the plunger moves in the axial direction in the direction approaching the attractor against the spring force of the separation spring, the attractor and the plunger are moved. Either one of them comes into contact with the movable member, and the buffer member is elastically deformed through the movable member. Due to the elastic deformation of the buffer member, the impact impact sound between the other of the suction element and the plunger and the movable member is attenuated.

  When the electromagnetic coil is demagnetized and the magnetic attractive force of the attractor disappears, the plunger moves axially in the direction away from the attractor by the spring force of the separation spring. At this time, even if the buffer member made of rubber-like elastic material is in a fixed state, this sticking is performed by the suction element provided so that the movable member can move in the axial direction across the buffer member made of rubber-like elastic material. Since it occurs between any one of the plungers and the movable member, it is not hindered that the plunger moves in the axial direction in a direction away from the suction element.

  As a result, without causing troubles such as sticking of the plunger and sliding obstruction, normal on-off valve operation is ensured over a long period of time, and impact noise generated during operation is effectively reduced.

  Embodiment 1 of an electromagnetic valve according to the present invention will be described with reference to FIGS.

  As shown in FIG. 1, the solenoid valve has a valve housing 11. The valve housing 11 has a valve chamber 12, two fluid inlet / outlet ports 13 and 14, and a valve port 15. The valve housing 11 defines an annular ridge-shaped valve seat 16 on the outer periphery of the open end of the valve port 15 on the valve chamber 12 side.

  An upper lid member 18 is fixedly attached to the upper portion of the valve housing 11 with bolts 19 with an O-ring 17 interposed therebetween. The upper lid member 18 is integrally formed with a cylindrical plunger tube 21 of the electromagnetic solenoid device 20. Both the valve housing 11 and the upper lid member 18 are made of a nonmagnetic metal such as SUS316.

  A cylindrical plunger 22 made of magnetic metal such as SUS430 or the like is provided in the plunger tube 21 so as to be slidable in the axial direction (vertical direction). The plunger 22 integrally has a valve body 23 at the lower end.

  An O-ring groove 24 is formed on the outer periphery of the lower end of the valve body 23. An O-ring 25 made of ethylene propylene rubber or the like is fitted in the O-ring groove 24. In addition, a cylindrical cover 26 for preventing the O-ring 25 from falling off is fixedly mounted on the outer periphery of the O-ring mounting portion of the valve body 23.

  The valve body 23 approaches the valve seat portion 16 side by the downward movement, and is seated on the valve seat portion 16 with the O-ring 25, thereby closing the valve port 15 and closing the valve, and the valve seat portion 16 by the upward movement. By separating further, the valve port 15 is opened.

  A cylindrical suction element 27 made of magnetic metal such as SUS430 or the like is fixedly attached to the upper end portion of the plunger tube 21 so as to close the upper end opening of the plunger tube 21. The outer circumferences of the plunger tube 21 and the suction element 27 have the same outer diameter, and a resin-molded electromagnetic coil 28 is fixed to the outer circumference part together with an outer rod 30 fixed to the upper end portion of the suction element 27 by a bolt 29. It is installed.

  The upper end portion of the plunger 22 and the lower end portion of the attractor 27 are opposed to each other in the vertical axis direction in the plunger tube 21, and the attractor 27 causes the plunger 22 to move to the lower end portion by excitation of the electromagnetic coil 28 by energization. Magnetic attraction that attracts magnetically is generated.

  A receiving hole 31 having a bottomed downward opening is formed at the center of the lower end of the suction element 27. A movable member 32 made of a nonmagnetic metal such as SUS316 is fitted in the receiving hole 31 so as to be movable in the axial direction. Needless to say, an appropriate clearance is provided between the inner peripheral surface of the receiving hole 31 and the outer peripheral surface of the movable member 32 so that the movable member 32 can smoothly slide in the receiving hole 31 in the axial direction. ing.

  An O-ring mounting recess 34 is formed at the upper end of the movable member 32 facing the bottom 33 of the receiving hole 31. An O-ring 35 made of ethylene propylene rubber or the like is mounted on the O-ring mounting recess 34 as a cushioning member made of a rubber-like elastic material in a tightly fitted state.

  As a result, the O-ring 35 serving as a buffer member is disposed between the bottom 33 of the receiving hole 31 and the upper end of the movable member 32 facing the bottom 33. Furthermore, in other words, the movable member 32 is provided at the lower end portion of the suction element 27 so as to be movable in the axial direction with an O-ring 35 as a cushioning member made of rubber-like elastic material interposed therebetween.

  As shown in FIG. 2A, the depth Da of the O-ring mounting recess 34 is smaller by a predetermined amount ΔP than the wire diameter Db of the O-ring 35 when not compressed. As a result, the O-ring 35 mounted in the O-ring mounting recess 34 protrudes upward (to the bottom 33 side of the receiving hole 31) by a predetermined amount ΔP from the upper end surface 32A of the movable member 32 in the non-compressed state. The protrusion height by the predetermined amount ΔP is defined as the maximum compression allowance of the O-ring 35.

  At the center of the upper end of the plunger 22, an annular protrusion 36 having an outer diameter sufficiently smaller than the inner diameter of the receiving hole 31 is formed. When the electromagnetic coil 28 is energized, it is shown in FIGS. 2 (b) and 2 (c). As shown, the upper end surface 36 </ b> A of the annular protrusion 36 is in contact with the lower end surface 32 </ b> B of the movable member 32.

  An annular lower end surface that exists around the receiving hole 31 of the attractor 27 and an annular upper end surface that exists around the annular projecting portion 36 of the plunger 22 face each other, and are not in contact with each other. 37 and 38.

  As shown in FIG. 1, in a non-energized state (demagnetized state) in which the electromagnetic coil 28 is not excited, the plunger 22 is in the lowest lowered position by the spring force of the separation spring 41 described later, that is, the valve body. In the valve closed state in which 23 is seated on the valve seat 16 with the O-ring 25, as shown in FIG. 2 (a), the axial gap La between the magnetic attraction surfaces 37 and 38 is such that the plunger 22 in the same state The axial distance Lb between the upper end surface 36A of the annular protrusion 36 and the lower end surface 32B of the movable member 32 (see FIG. 2A) is set to be greater than the predetermined amount ΔP.

  As a result, as shown in FIGS. 2B and 2C, the electromagnetic coil 28 is excited and the magnetic attracting surface 38 of the plunger 22 is magnetically attracted to the magnetic attracting surface 37 of the attractor 27. However, the magnetic attraction surfaces 37 and 38 maintain a non-contact state in which they do not contact.

  A concave spring receiving seat 39 is formed at the lower end of the movable member 32 opposite to the upper end of the movable member 32 facing the bottom 33 of the receiving hole 31. Between the spring receiving seat 39 and the concave spring receiving seat 40 formed at the upper end of the plunger 22, the plunger 22 is biased in the direction away from the lower end of the suction element 27, that is, in the valve closing direction. The separating spring 41 is sandwiched. In addition, the spring receiving seat part 39 and the spring receiving seat part 40 are set to the outer diameter which becomes a clearance fit with the separation spring 41.

  As shown in FIG. 1, pressure equalization passages 42 and 43 are formed in the plunger 22, and pressure equalization passage 44 is formed in the movable member 32.

  Next, the operation of the solenoid valve according to the first embodiment will be described.

  As shown in FIGS. 1 and 2A, in the non-energized state (demagnetized state) in which the electromagnetic coil 28 is not excited, the plunger 22 is pushed down by the spring force of the separation spring 41, and the valve element 23 is The valve is closed with the O-ring 25 seated on the valve seat 16.

  In this valve-closed state, the O-ring 35 is lightly sandwiched between the movable member 32 and the bottom 33 of the receiving hole 31 without being substantially elastically deformed in the compression direction by the spring force of the separation spring 41, and magnetically. The suction surfaces 37 and 38 are separated from each other with an axial gap La, and the upper end surface 36A of the annular protrusion 36 of the plunger 22 and the lower end surface 32B of the movable member 32 are also separated with an axial gap Lb.

  When the electromagnetic coil 28 is energized and the electromagnetic coil 28 is excited, the plunger 22 is magnetically attracted to the magnetic attraction surface 37 of the attractor 27 by the magnetic attraction surface 38 by the magnetic attraction between the magnetic attraction surfaces 37 and 38. The plunger 22 moves in the axial direction (upward movement) in the direction approaching the lower end of the suction element 27 against the spring force of the separation spring 41.

  As a result, the O-ring 25 of the valve body 23 is separated from the valve seat portion 16, the valve port 15 is opened, and the valve is opened. Due to the upward movement of the plunger 22, the upper end surface 36 </ b> A of the annular protrusion 36 of the plunger 22 contacts the lower end surface 32 </ b> B of the movable member 32, as shown in FIG.

  Even after this contact state, the magnetic attraction surface 38 of the plunger 22 approaches the magnetic attraction surface 37 of the attractor 27 due to magnetic attraction by the excitation of the electromagnetic coil 28, and accordingly the movable member 32 becomes the annular protrusion of the plunger 22. The movable member 32 is pushed upward by 36 and moves up in the receiving hole 31 while elastically deforming the O-ring 35 in the compression direction.

  As shown in FIG. 2C, the elastic deformation of the O-ring 35 accompanying the upward movement of the movable member 32 includes a magnetic attraction force due to the excitation of the electromagnetic coil 28, a spring force of the separation spring 41, and an O The process is performed until the repulsive force due to the elastic deformation of the ring 35 is balanced, and the impact shock sound between the plunger 22 and the movable member 32 is attenuated by the elastic deformation of the O-ring 35.

  The balance between the magnetic attraction force due to the excitation of the electromagnetic coil 28, the spring force of the separation spring 41, and the repulsion force due to the elastic deformation of the O-ring 35 includes the magnetic attraction force due to the excitation of the electromagnetic coil 28, the spring force of the separation spring 41, O By selecting the rubber hardness of the ring 35, the upper end surface 32A of the movable member 32 is obtained just before contacting the bottom portion 33 of the receiving hole 31, and in this balanced state, the upper end surface 32A of the movable member 32 and the bottom portion of the receiving hole 31 are obtained. A minute gap Ga is secured between the movable member 32 and the upper end surface 32 </ b> A of the movable member 32 so as not to collide with the bottom 33 of the receiving hole 31. Therefore, no collision sound is generated in this portion.

  Even in this balanced state, the magnetic attraction surface 38 of the plunger 22 does not collide with the magnetic attraction surface 37 of the attractor 27, and the magnetic attraction surfaces 37 and 38 are maintained in a non-contact state with a gap Gb. Therefore, no collision noise is generated even in this portion.

  When the valve is opened from the above-described state, energization to the electromagnetic coil 28 is stopped and the electromagnetic coil 28 is demagnetized. As a result, the magnetic attractive force of the attractor 27 disappears, and the plunger 22 moves in the axial direction (downward movement) in the direction away from the lower end of the attractor 27 by the spring force of the separation spring 41.

  At this time, even when the O-ring 35 made of a rubber-like elastic material is fixed to the bottom 33 of the receiving hole 31, this fixing occurs between the suction element 27 and the movable member 32. Even if the movement is hindered, the plunger 22 is not hindered from moving in the axial direction in the direction away from the lower end portion of the suction element 27, and the valve body 23 has the O-ring 25 by the downward movement of the plunger 22. An appropriate valve closed state seated on the seat portion 16 can be obtained without hindrance.

  As a result, the normal on-off valve operation is ensured over a long period of time without causing other problems such as sticking of the plunger 22 and sliding trouble, and the impact sound generated during operation is effectively reduced. The

  The actions and effects of the electromagnetic valve according to this embodiment are summarized as follows.

(1) The plunger operating impact force when the solenoid valve is energized is attenuated by the O-ring 35 that is a buffer material via the movable member 32.

(2) Since the rubber-like elastic O-ring 35 is not directly sandwiched between the plunger 22 and the suction element 27, even if the O-ring 35 is fixed during energization, the plunger 22 is not hindered, and the plunger 22 There is no hindrance to withdrawal.

(3) The movable member 32 and the O-ring 35 are locked to the O-ring mounting recess 34 by the separation spring 41, and can always stably absorb the impact force when the valve is opened. Even when the valve is closed, the movable member 32 and the O-ring 35 do not move freely.

(4) The movable member 32 is a nonmagnetic metal, is not magnetized even when energized, and transmits the impact force of the plunger 22 to the O-ring 35 without any stagnation. Even if the wear powder of the plunger 22 is generated and magnetized, the attracting surface is a combination of a magnetic material and a non-magnetic material, and does not prevent the plunger 22 from being detached.

(5) The movable member 32 is a non-magnetic metal and is not magnetized when energized, and does not swell or expand.

(6) The movable member 32 is slidably disposed in the receiving hole 31 and can stably transmit the impact force of the plunger 22 to the O-ring 35. Further, the movable member 32 does not enlarge the magnetic gap (axial gap La) between the plunger 22 and the attractor 27, and the power consumption of the electromagnetic coil 28 does not increase.

(7) One end of the movable member 32 is a holding portion for the O-ring 35, and the other end is a spring receiver for the separation spring 41, and the O-ring 35 and the separation spring 41 are not detached or caught.

  A second embodiment of the electromagnetic valve according to the present invention will be described with reference to FIGS. In FIGS. 3 and 4, parts corresponding to those in FIGS. 1 and 2 are denoted by the same reference numerals as those in FIGS. 1 and 2, and description thereof is omitted.

  As shown in FIG. 3, a receiving hole 51 having a bottomed upward opening is formed at the center of the upper end portion of the plunger 22. In the receiving hole 51, a movable member 32 made of a nonmagnetic metal such as SUS316 is fitted so as to be movable in the axial direction in a posture opposite to that of the first embodiment. Needless to say, an appropriate clearance is provided between the inner peripheral surface of the receiving hole 51 and the outer peripheral surface of the movable member 32 so that the movable member 32 can smoothly slide in the receiving hole 51 in the axial direction. ing.

  An O-ring mounting recess 34 is formed at the lower end of the movable member 32 facing the bottom 52 of the receiving hole 51, and the O-ring mounting recess 34 is made of a rubber-like elastic material, as in the first embodiment. As the buffer member, an O-ring 35 made of ethylene propylene rubber or the like is mounted in a tightly fitted state.

  Thereby, the O-ring 35 which is a buffer member is disposed between the bottom 52 of the receiving hole 51 and the lower end of the movable member 32 facing the bottom 52. Furthermore, in other words, the movable member 32 is provided at the upper end of the plunger 22 so as to be movable in the axial direction with an O-ring 35 serving as a buffer member made of rubber-like elastic material interposed therebetween.

  Also in this embodiment, as shown in FIG. 4, the depth Da of the O-ring mounting recess 34 is smaller by a predetermined amount ΔP than the wire diameter Db of the O-ring 35 when not compressed. As a result, the O-ring 35 mounted in the O-ring mounting recess 34 is below the upper end surface 32A of the movable member 32 (the lower end surface of the movable member 32 in FIG. 4) by a predetermined amount ΔP in an uncompressed state. (The bottom 52 side of the receiving hole 51) protrudes, and the protrusion height by this predetermined amount ΔP is defined as the maximum compression allowance of the O-ring 35.

  An annular protrusion 53 having an outer diameter that is sufficiently smaller than the inner diameter of the receiving hole 51 is formed at the center of the lower end of the attractor 27. When the electromagnetic coil 28 is energized, the lower end surface 53A of the annular protrusion 53 is The movable member 32 is in contact with the lower end surface 32B (the upper end surface of the movable member 32 in FIG. 4).

  An annular lower end surface that exists around the annular protrusion 53 of the attractor 27 and an annular upper end surface that exists around the receiving hole 51 of the plunger 22 face each other and are not in contact with each other. 37 and 38.

  Also in this embodiment, as shown in FIG. 3, the plunger 22 is in the lowest lowered position by the spring force of the separation spring 41 in a non-energized state (demagnetized state) where the electromagnetic coil 28 is not excited, that is, When the valve body 23 is seated on the valve seat 16 with the O-ring 25, as shown in FIG. 4, the axial clearance La between the magnetic attracting surfaces 37 and 38 is the same as that shown in FIG. The axial gap Lb between the lower end surface 53A of the annular protrusion 53 of the suction element 27 and the lower end surface 32B of the movable member 32 (the upper end surface of the movable member 32 in FIG. 4) is set larger than the predetermined amount ΔP. Has been.

  Thus, even in this embodiment, even if the electromagnetic coil 28 is excited and the magnetic attraction surface 38 of the plunger 22 is magnetically attracted to the magnetic attraction surface 37 of the attractor 27, the magnetic attraction surfaces 37 and 38 are Maintain a non-contact state that does not contact.

  A concave spring receiving seat 39 is formed at the upper end of the movable member 32 opposite to the lower end of the movable member 32 facing the bottom 52 of the receiving hole 51. Between the spring receiving seat 39 and the concave spring receiving seat 54 formed at the lower end of the suction element 27, the plunger 22 is attached in a direction away from the lower end of the suction element 27, that is, in the valve closing direction. A separating spring 41 is sandwiched. In addition, the spring receiving seat part 39 and the spring receiving seat part 54 are set to the outer diameter which becomes a clearance fit with the separation spring 41.

  Next, the operation of the electromagnetic valve according to the second embodiment will be described.

  As shown in FIG. 3, in a non-energized state (demagnetized state) where the electromagnetic coil 28 is not excited, the plunger 22 is pushed down by the spring force of the separation spring 41, and the valve body 23 holds the valve seat with the O-ring 25. The valve seated on the portion 16 is closed.

  In this valve closed state, as shown in FIG. 4, the O-ring 35 is not substantially elastically deformed in the compression direction by the spring force of the separation spring 41, and the bottom of the movable member 32 and the receiving hole 51. 52, the magnetic attraction surfaces 37 and 38 are separated from each other with an axial gap La, and the lower end surface 53A of the annular protrusion 53 of the attractor 27 and the lower end surface 32B of the movable member 32 (FIG. 4). Among them, the upper end surface of the movable member 32 is also separated with an axial gap Lb.

  When the electromagnetic coil 28 is energized and the electromagnetic coil 28 is excited, the plunger 22 is magnetically attracted to the magnetic attraction surface 37 of the attractor 27 by the magnetic attraction surface 38 by the magnetic attraction between the magnetic attraction surfaces 37 and 38. The plunger 22 moves in the axial direction (upward movement) in the direction approaching the lower end of the suction element 27 against the spring force of the separation spring 41.

  As a result, the O-ring 25 of the valve body 23 is separated from the valve seat portion 16, the valve port 15 is opened, and the valve is opened. Due to the upward movement of the plunger 22, the lower end surface 32 </ b> B of the movable member 32 (the upper end surface of the movable member 32 in FIG. 4) contacts the lower end surface 53 </ b> A of the annular protrusion 53 of the suction element 27.

  Even after this contact state, the magnetic attraction surface 38 of the plunger 22 approaches the magnetic attraction surface 37 of the attractor 27 by the magnetic attraction by the excitation of the electromagnetic coil 28, so that the upward movement of the movable member 32 is stopped. The plunger 22 moves upward. Accordingly, when viewed relatively, the movable member 32 is pushed downward by the annular protrusion 53 of the suction element 27 with respect to the plunger 22, and the movable member 32 elastically deforms the O-ring 35 in the compression direction while receiving the receiving hole. 51 moves downward while relatively looking inside.

  The elastic deformation of the O-ring 35 accompanying the downward movement of the movable member 32 relative to the plunger 22 is repulsive due to the magnetic attraction force due to the excitation of the electromagnetic coil 28, the spring force of the separation spring 41, and the elastic deformation of the O-ring 35. The process is performed until the force is balanced, and the impact shock noise between the plunger 22 and the movable member 32 is attenuated by the elastic deformation of the O-ring 35.

  The balance between the magnetic attraction force due to the excitation of the electromagnetic coil 28, the spring force of the separation spring 41, and the repulsion force due to the elastic deformation of the O-ring 35 includes the magnetic attraction force due to the excitation of the electromagnetic coil 28, the spring force of the separation spring 41, O By selecting the rubber hardness of the ring 35, the upper end surface 32A of the movable member 32 (the lower end surface of the movable member 32 in FIG. 4) is obtained just before contacting the bottom 52 of the receiving hole 51. A small gap is secured between the upper end surface 32A of the movable member 32 (the lower end surface of the movable member 32 in FIG. 4) and the bottom 52 of the receiving hole 51, and the upper end surface 32A of the movable member 32 (in FIG. 4). Then, the lower end surface of the movable member 32 does not collide with the bottom 52 of the receiving hole 51. Therefore, no collision sound is generated in this portion.

  Even in this balanced state, the magnetic attraction surface 38 of the plunger 22 does not collide with the magnetic attraction surface 37 of the attractor 27, and the magnetic attraction surfaces 37 and 38 are maintained in a non-contact state. Therefore, no collision noise is generated even in this portion.

  When the valve is opened from the above-described state, energization to the electromagnetic coil 28 is stopped and the electromagnetic coil 28 is demagnetized. As a result, the magnetic attractive force of the attractor 27 disappears, and the plunger 22 moves in the axial direction (downward movement) in the direction away from the lower end of the attractor 27 by the spring force of the separation spring 41.

  At this time, even when the O-ring 35 made of a rubber-like elastic material is fixed to the bottom 52 of the receiving hole 51, this fixing occurs between the plunger 22 and the movable member 32, and hence the movement of the movable member 32. Even if the plunger 22 is hindered, the plunger 22 is not hindered from moving in the axial direction in the direction away from the lower end portion of the suction element 27. An appropriate valve closed state seated on the portion 16 can be obtained without hindrance.

  As a result, in this embodiment as well, the same effect as in the first embodiment can be obtained, and normal on-off valve operation can be performed over a long period of time without causing other problems such as fixation of the plunger 22 and sliding obstruction. Assured, the impact sound generated during operation is effectively reduced.

It is a longitudinal cross-sectional view which shows Embodiment 1 of the solenoid valve by this invention. (A)-(c) is a longitudinal cross-sectional view of the principal part which shows the operating state of the solenoid valve by Embodiment 1. FIG. It is a longitudinal cross-sectional view which shows Embodiment 2 of the solenoid valve by this invention. It is a longitudinal cross-sectional view of the principal part which shows the operating state of the solenoid valve by Embodiment 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Valve housing 12 Valve chamber 13, 14 Fluid inlet / outlet port 15 Valve port 16 Valve seat part 17 O-ring 18 Upper cover member 19 Bolt 20 Electromagnetic solenoid device 21 Plunger tube 22 Plunger 23 Valve body 24 O-ring groove 25 O-ring 26 Cylindrical cover 27 Attractor 28 Electromagnetic coil 29 Bolt 30 Outer flange 31, 51 Receiving hole 32 Movable member 33, 52 Bottom 34 O-ring mounting recess 35 O-ring 36, 53 Toroidal protrusion 37, 38 Magnetic attraction surface 39, 40, 54 Spring receiving seat 41 Separating spring 42, 43, 44 Pressure equalizing passage

Claims (5)

An electromagnetic coil, a fixedly arranged attractor that generates a magnetic attractive force by excitation of the electromagnetic coil, a plunger that is magnetically attracted to the attractor and moves in an axial direction, and is connected to the plunger, and is in an axial direction of the plunger In an electromagnetic valve having a valve body that opens and closes by movement and a separation spring that urges the plunger in a direction to separate the plunger from the attractor,
A movable member is provided on one of the attractor and the plunger so as to be movable in the axial direction with a rubber-like elastic cushioning member interposed therebetween, and when the plunger is magnetically attracted by the attractor, An electromagnetic valve in which one of the plungers is in contact with the movable member.   A bottomed receiving hole is formed in one of the suction element and the plunger, and the movable member is slidably fitted in the receiving hole so as to be slidable in the axial direction, and the bottom of the receiving hole and the movable member The solenoid valve according to claim 1, wherein the buffer member is disposed therebetween.   The solenoid valve according to claim 2, wherein a non-contact magnetic attraction surface for the other of the attraction element and the plunger is formed at the periphery of the receiving hole, and the movable member is made of a non-magnetic material.   The electromagnetic valve according to claim 1, wherein the buffer member is attached to the movable member in a state where a maximum compression allowance is defined.   2. The spring receiving seat portion of one of the separation springs is formed at a portion of the movable member where either the plunger or the plunger abuts when the plunger is magnetically attracted by the attractor. The electromagnetic valve of any one of -4.

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