JP2013076439A - Solenoid valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solenoid valve in which a valve can be opened even by a small attracting force, and reduction of operating sound can be attained.SOLUTION: A valve body is held relatively displaceably for a predetermined quantity in a stroke direction of a movable iron core by the movable iron core. A relative displaceable quantity of the valve body to the movable iron core is set smaller than the stroke quantity of the movable iron core. A through hole communicating to a valve hole in the inner periphery of a valve seat is arranged in the valve body. A seal lip contacting so as to be able to contact and depart from the movable iron core is arranged in the end face of the movable iron core side of the valve body and around the through hole. A seal area by the seal lip is set smaller than a seal area by the valve seat. A primary fluid pressure can act on the end face of the movable iron core side of the valve body.

Description

  The present invention relates to an electromagnetic valve which is a kind of valve device. The electromagnetic valve of the present invention is used, for example, in a water supply section in a warm water washing toilet seat, or as other fluid control component.

  Conventionally, as shown in FIG. 4, the normally closed type is excited when the electromagnetic coil 51 is energized, the movable iron core 52 is attracted to the fixed iron core 53, and the valve body 54 held by the movable iron core 52 is a valve seat 55. An electromagnetic valve is known that opens when it is separated from the valve (see Patent Document 1).

  In the solenoid valve, since both the movable iron core 52 and the fixed iron core 53 are made of a ferromagnetic metal, an operating sound (collision sound) may be generated when the movable iron core 52 collides with the fixed iron core 53 during suction. There is a need to reduce such operating noise as much as possible because it may cause discomfort to the surroundings depending on the usage environment.

  As a measure for reducing the operating noise, a technique of avoiding collision between metal surfaces by sandwiching an elastic body such as rubber between the movable iron core 52 and the fixed iron core 53 is employed.

  However, this method can be applied to a normal solenoid valve that applies a constant voltage. In recent years, variable control for the purpose of miniaturization and power saving of the solenoid valve, particularly duty control that gives a pulse at a constant frequency, With solenoid valves that reduce power consumption by PWM control, problems such as the movable iron core separating from the fixed iron core when the pulse is OFF, or generating a squeaking noise until it does not leave, reduce operating noise. Have difficulty. In order to reduce the operating noise, it is necessary to use the method described above. To this end, it is necessary to increase the size of the solenoid valve and apply a constant voltage, and this environment is required for downsizing and low power consumption. It was difficult to solve conflicting problems.

JP 2000-257744 A JP 2005-172151 A

  The present invention has been made in view of the above points, and an object thereof is to provide an electromagnetic valve that can be operated to open even with a small suction force and at the same time can achieve a reduction in operating noise.

  In order to achieve the above object, an electromagnetic valve according to a first aspect of the present invention includes an electromagnetic coil, a fixed core that is excited by energization of the electromagnetic coil, and a magnet that is excited by energization of the electromagnetic coil and is magnetically applied to the fixed core. In a solenoid valve comprising: a movable iron core to be sucked; a valve body that is held by the movable iron core so as to be in contact with and separable from a valve seat; The valve body is held by the movable iron core so as to be relatively displaceable over a predetermined amount in the stroke direction of the movable iron core, and the relative displacement amount of the valve body with respect to the movable iron core is set smaller than the stroke amount of the movable iron core. The valve body is provided with a through hole that communicates with the valve hole on the inner periphery of the valve seat, and can be moved toward and away from the movable core around the through hole on the movable core side of the valve body A seal lip that abuts is provided, a seal area by the seal lip is set smaller than a seal area by the valve seat, and a primary fluid pressure can be applied to an end surface of the valve body on the movable core side. It is characterized by.

  The electromagnetic valve according to a second aspect of the present invention is the electromagnetic valve according to the first aspect, wherein the movable iron core is provided with a cylindrical holding portion to hold the valve body in a relatively displaceable manner. In order to prevent the valve body from coming off, a bent portion toward the inner diameter direction is provided at the tip of the holding portion.

The solenoid valve of the present invention having the above-described configuration is in a state where the valve body is pressed against the valve seat by the spring force (reaction force) of the spring means and the fluid pressure (primary fluid pressure) in the normal state (when not energized). Yes, so the valve is closed. The valve body is provided with a through-hole leading to the valve hole on the inner periphery of the valve seat, but the seal lip provided around the through-hole on the movable iron core side of the valve body is in contact with the movable iron core. Therefore, the through hole is substantially closed. At this time, the force F _{1 in the} valve closing direction applied to the movable iron core is
F ₁ = (spring force of the spring means) + (seal area by the seal lip) × (fluid pressure) (A) On the other hand, the valve closing force F _{2 applied} to the valve body is ,
F ₂ = (spring force of the spring means) + ((seal area by the valve seat) − (seal area by the seal lip)) × (fluid pressure) (b) formula, and the seal area by the seal lip is By setting it smaller than the seal area by the valve seat, the dimensions are set so that F ₁ <F ₂ . Next, by energizing the coil, a suction force P is generated between the movable iron core and the fixed iron core, and when this suction force P exceeds F ₁ (P> F ₁ ... (C) formula), the movable iron core. However, since the valve element can be displaced relative to the movable core in the stroke direction of the movable core over a predetermined amount, only the movable core moves momentarily. The movable core moves away from the seal lip due to a slight movement of the movable core, the sealing performance between the movable core and the valve body is lost, and fluid pressure is applied to the valve hole side (output side) through the through hole of the valve body. Become. In this state, there is no pressure difference before and after the valve body, and since the movable iron core is also detached, there is no spring force of the spring means, so F ₂ ≈0. Finally, the valve body is held by the movable iron core and is separated from the valve seat, so that the valve is opened. In the prior art in which the valve body is integrated with the movable iron core, this is not the above formula (c),
P> (spring force of spring means) + (seal area by valve seat) x (fluid pressure) ... (d) Since the valve is opened by the formula (4), a large suction force is required to operate even in high water pressure areas. According to the present invention, it is possible to operate even with a small suction force by setting the seal area by the seal lip in the valve body small, and at the same time, it is possible to reduce the operating noise. it can.

  Since the movable iron core holds the valve body in a relatively displaceable manner, it is preferable that the movable iron core is provided with a cylindrical holding portion, and since the holding portion prevents the valve body from coming off, the holding portion has an inner diameter direction at the tip thereof. It is preferable to provide a bent portion toward the head. In addition, in order to apply the primary fluid pressure to the end surface of the valve body on the movable iron core side, a part of the circumferential flow path is provided on the outer peripheral surface of the valve body, or a radial gap is provided between the holding portion and the valve body. It is preferable to set or provide a communication hole in the movable iron core.

  The present invention has the following effects.

  That is, according to the present invention, as described above, by setting the seal area by the seal lip in the valve body to be smaller than the seal area by the valve seat, the valve can be opened even with a small suction force. Reduction can be achieved.

Sectional drawing of the solenoid valve based on the Example of this invention 1 is an enlarged view of the main part of FIG. The perspective view of the valve body with which the solenoid valve is equipped Cross-sectional view of a conventional solenoid valve

The present invention includes the following embodiments.
(1) As a method for reducing the operation sound of the solenoid valve, it is possible to inevitably reduce the operation sound (collision sound) if the movable iron core easily operates even when the suction force of the solenoid valve is small. However, we propose a structure that avoids an increase in the number of parts, such as the addition of a water stop diaphragm, and an increase in size due to the addition of parts.
(2) About the water stop rubber (valve) of the solenoid valve, a seal surface having a through hole smaller than the original seal diameter of the solenoid valve (valve seat diameter) at the center of the water stop rubber and continuing from the through hole ( A seal lip) is provided, and the water stop rubber is movable in the axial direction while being cylindrically supported in the movable iron core. The movable amount of the still water rubber should be less than the stroke amount of the movable iron core.
(3) When the movable iron core is lifted by energization, the valve body is pressed against the valve seat side due to the primary / secondary pressure difference. Hole). The valve then becomes easier to open.
(4) According to the above (1) to (3), a solenoid valve for a hot water flush toilet seat that reduces operating noise and obtains a comfortable space in the solenoid valve installation environment without changing the performance and appearance of the solenoid valve A comfortable use environment can be provided in a limited sealed space.

  Next, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows an overall cross section of a solenoid valve according to an embodiment of the present invention, and the main part thereof is shown in an enlarged manner in FIG. FIG. 3 is a single perspective view of the valve body 6 provided in the electromagnetic valve. The solenoid valve according to this embodiment is used in a water supply section in a warm water washing toilet seat, and is configured as follows.

  That is, as shown in FIG. 1, the electromagnetic valve includes a body 1, a bobbin 2, an electromagnetic coil 3 wound around the outer periphery of the bobbin 2, and a fixed arrangement on the inner peripheral side of the bobbin 2. A fixed iron core (center post) 4 that is excited by energization of the electromagnetic coil 3 and an inner peripheral side of the bobbin 2 that is coaxial with the fixed iron core 4 and is excited and fixed by energization of the electromagnetic coil 3. A movable iron core (plunger) 5 that is magnetically attracted to the iron core 4, a valve body (water blocking rubber) 6 that is held at one end in the stroke direction of the movable iron core 5 and contacts the valve seat (body seal surface) 14 detachably; Spring means (water stop spring) 7 is provided between the fixed iron core 4 and the movable iron core 5 and urges the movable iron core 5 in a direction away from the fixed iron core 4. An O-ring 8 is arranged as a sealing means between the body 1 and the bobbin 2, and an O-ring 9 is also arranged as a sealing means between the bobbin 2 and the fixed iron core 4. Reference numeral 10 denotes a mold that covers the outer periphery of the coil 3, 11 denotes a connector that supplies power to the coil 3, and 12 denotes a yoke that forms a magnetic circuit with the fixed iron core 4 and the movable iron core 5. The body 1 is provided with a valve chamber 13, and a valve seat 14 with which the valve body 6 comes into contact with the valve chamber 13 so as to be able to contact and separate is provided. The valve chamber 13 communicates directly with the primary side input port 15 and also communicates with the secondary side output port 17 through a valve hole 16 in the inner periphery of the valve seat 14.

  As shown in FIGS. 2 and 3 in an enlarged manner, the valve body 6 is formed into a disc shape by a predetermined rubber-like elastic body. Further, a downward stepped portion 6a having an annular shape is provided on the outer peripheral surface of the valve body 6, and a portion above the stepped portion 6a is a large diameter portion (large diameter disc portion) 6b and a lower portion. Is a small diameter portion (small diameter disk portion) 6c. The valve body 6 is provided with a through hole 6d that is located in the center of the plane and penetrates the valve body 6 in the thickness direction, that is, in the axial direction. The through hole 6d is formed in the valve hole 16 in the inner periphery of the valve seat 14. It is supposed to open and communicate here. Further, an upper seal lip (valve seal surface) 6f having an annular shape is provided around the upper end surface 6e of the valve body 6, that is, the end surface on the movable iron core 5 side and around the opening of the through hole 6d. The movable core 5 is in contact with the lower end surface 5a of the movable iron core 5 so as to be able to contact and separate. Further, a part of the groove-like channel 6g on the circumference is provided on the outer peripheral surface of the valve body 6 on the outer peripheral surface of the large-diameter portion 6b so as to penetrate the large-diameter portion 6b in the thickness direction, that is, the axial direction. Yes. The lower end surface 6h of the valve body 6, that is, the end surface on the valve seat 14 side is a flat surface. A plurality of groove-like flow paths 6g may be provided on the circumference.

  The valve body 6 is held by the movable iron core 5 so as to be relatively displaceable over a predetermined amount in the stroke direction (axial direction) of the movable iron core 5. For this reason, the cylindrical holding part 5b is provided in the lower end part of the movable iron core 5, and the valve body 6 is accommodated in the inner peripheral side of the holding part 5b so as to be movable in the axial direction. Further, in order to prevent the valve body 6 from coming off from the holding portion 5b, a bent portion (crimping portion) 5c toward the inner diameter direction is provided at the tip (lower end) of the holding portion 5b, and a step of the valve body 6 is provided at the bent portion 5c. By engaging the portion 6a, the valve body 6 is prevented from being detached from the holding portion 5b.

FIG. 2 shows the closed state of the solenoid valve. The lower end surface 6h of the valve body 6 abuts on the valve seat 14, and the seal lip 6f provided on the upper end surface 6e abuts on the lower end surface 5a of the movable iron core 5. ing. In this case a predetermined axial gap c ₁ is set between the stepped portion 6a of the bent portion 5c and the valve body 6 provided in the holding portion 5b lower end of the movable iron core 5, thus the valve body 6 is the axial gap c _In the range of ₁ , it is possible to make a relative displacement in the axial direction with respect to the movable iron core 5.

Further, the relative displacement can amount for the movable iron core 5 of the axial gap c ₁ i.e. the valve body 6 is set smaller than the stroke amount ST of the movable iron core 5, thus upwardly moving core 5 is attracted to the fixed iron core 4 When moved, the movable iron core 5 lifts the valve body 6 at the bent portion 5c, and the valve body 6 can be separated from the valve seat 14.

The sealing lip 6f provided on the upper end surface 6e of the valve body 6, which seal the area S ₁ when in contact with the lower end face 5a of the movable iron core 5, when the valve body 6 is in contact with the valve seat 14 It is set smaller than the seal area S ₂ by the valve seat 14 (S ₁ <S ₂ ), and the former seal area S ₁ is set smaller than the difference between the seal areas S ₁ and S ₂ (S _{1 <S} 2 _{-S 1).} Note that S ₁ <S ₂ in this way means that, in other words, the diameter of the seal lip 6 f is set smaller than the diameter of the valve seat 14.

The predetermined radial clearance c ₂ is set between the outer peripheral surface or outer peripheral surface of the small-diameter portion 6c of the front end of the bent portion 5c and the valve body 6. As described above, a part of the groove-shaped flow path 6g on the circumference is provided on the outer peripheral surface of the valve body 6 and on the outer peripheral surface of the large-diameter portion 6b. Thus there is a possible primary pressure valve chamber 13 through these radial clearance c ₂ and the groove-like channel 6g acts on the upper end surface 6e i.e. the end face of the movable iron core 5 side of the valve body 6.

The solenoid valve having the above configuration is in a state in which the valve body 6 is pressed against the valve seat 14 by the spring force (reaction force) of the spring means 7 and the water pressure (primary water pressure) in its normal state (when not energized). Therefore, the valve is closed. The valve body 6 is provided with a through hole 6d. However, since the seal lip 6f is in contact with the movable iron core 5, the through hole 6d is substantially closed. At this time, the force F _{1 in the} valve closing direction applied to the movable iron core 5 is
F ₁ = (spring force of the spring means 7) + (seal area S ₁ by the seal lip 6f) × (hydraulic pressure) (b) On the other hand, in the valve closing direction applied to the valve body force _{F 2} is,
F ₂ = (spring force of the spring means 7) + ((seal area S ₂ by the valve seat 14) − (seal area S ₁ by the seal lip 6f)) × (water pressure) (...) In the electromagnetic valve, as described above, S ₁ <S ₂ , S ₁ <S ₂ -S ₁ , and F ₁ <F ₂ is set. Therefore, when the suction force P generated by energization exceeds F ₁ (P> F ₁ ... (C) type), the movable iron core 5 is attracted to the fixed iron core 4, but the valve body 6 is movable armature. since it is possible relative displacement over a predetermined amount c ₁ to the stroke direction of the movable iron core 5 to 5, momentarily only the movable iron core 5 is small amount moved. When the movable iron core 5 is moved in a small amount in the axial direction, the movable iron core 5 is separated from the seal lip 6f, the sealing performance between the movable iron core 5 and the valve body 6 is lost, and the water pressure passes through the through hole 6d of the valve body 6 and the valve hole 16 It will be added to the side (output side). In this state, there is no difference in water pressure before and after (upper and lower) of the valve body 6, and the movable iron core 5 is also detached and there is no spring force of the spring means 7, so that F ₂ ≈0. Eventually, the valve body 6 is held by the bent portion 5c of the movable iron core 5 and is separated from the valve seat 14, so that the valve opens and enters a water passage state. In the prior art in which the valve body is integrated with the movable iron core, this is not the above formula (c),
P> (spring force of spring means) + (seal area by valve seat) x (water pressure) ··· (d) formula, so a large suction force is required to operate even in high water pressure areas. where even greater sound, according to the present invention embodiment, by setting smaller than the seal area S ₂ by the sealing area S ₁ of the valve seat 14 by the seal lip 6f in the valve body 6, the valve opening operation even with a small suction force At the same time, a reduction in operating noise can be achieved.

  Further, in the electromagnetic valve having the above-described configuration, the valve body 6 held by the movable iron core 5 so as to be relatively displaceable is not a metal valve body but a rubber-like elastic valve body. is there.

  That is, when the valve body 6 is made of metal, there is a concern that when the valve body 6 comes into contact with the lower end surface 5a of the movable iron core 5 or the bent portion 5c as a result of relative displacement, an operating noise is generated due to contact between the metals. However, since the valve body is made of a rubber-like elastic body, such an operating noise is not generated. Moreover, since the elasticity peculiar to a rubber-like elastic body can be utilized, the seal lip 6f can be pressed against the movable iron core 5 without providing a spring means.

  In the above embodiment, as a structure for applying the primary water pressure to the upper end surface 6e of the valve body 6, that is, the end surface on the movable iron core 5 side, a part of the groove shape on the circumference is formed on the outer peripheral surface of the valve body 6. The flow path 6g is provided, but instead of this, a structure may be provided in which a radial gap is provided over the entire circumference between the holding part 5b and the valve body 6 (large diameter part 6b). Moreover, it is good also as a structure which provides a communicating hole in the movable core 5.

DESCRIPTION OF SYMBOLS 1 Body 2 Bobbin 3 Electromagnetic coil 4 Fixed iron core 5 Movable iron core 5a, 6h Lower end surface 5b Holding part 5c Bending part 6 Valve body 6a Step part 6b Large diameter part 6c Small diameter part 6d Through hole 6e Upper end face 6f Seal lip 6g Groove flow Path 7 Spring means 8, 9 O-ring 10 Mold 11 Connector 12 Yoke 13 Valve chamber 14 Valve seat 15 Input port 16 Valve hole 17 Output port

Claims (2)

An electromagnetic coil, a fixed iron core excited by energization of the electromagnetic coil, a movable iron core excited by energization of the electromagnetic coil and magnetically attracted to the fixed iron core, and held by the movable iron core and separated from the valve seat In a solenoid valve comprising: a valve body that abuts in a possible manner; and spring means that urges the movable iron core in a direction in which the movable iron core is separated from the fixed iron core.
The valve body is held by the movable iron core so as to be relatively displaceable over a predetermined amount in the stroke direction of the movable iron core, and the relative displacement amount of the valve body with respect to the movable iron core is set smaller than the stroke amount of the movable iron core. And
The valve body is provided with a through hole that communicates with the valve hole on the inner periphery of the valve seat, and is an end surface of the valve body on the side of the movable iron core that can be brought into contact with and separated from the movable iron core around the through hole. A seal lip that is in contact with the seal lip, a seal area by the seal lip is set smaller than a seal area by the valve seat, and a primary fluid pressure can be applied to an end surface of the valve body on the movable core side. Characteristic solenoid valve. The solenoid valve according to claim 1, wherein
A cylindrical holding portion is provided on the movable iron core to hold the valve body in a relatively displaceable manner, and a bent portion toward the inner diameter direction is provided at the tip of the holding portion to prevent the valve body from coming off. A solenoid valve characterized by that.

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