JPH10213257A - Solenoid valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily provide a compact solenoid valve. SOLUTION: A solenoid valve 10 involves a moving core 24 arranged outside a coil 32 so as to reciprocate in the direction perpendicular to the axis of the coil 32. That coil 32 not enclosing the moving core 24 is thus reduced in its size. The location of the coil 32 outside the reciprocating path of the moving part constituted of the moving core 24 and a valve element 25 also contributes to the smaller size of the moving core 24. The electromagnetic force required to attract the moving core 24 is thus correspondingly lessened to help to further reduce the size of the coil 32 and resultantly the total size of the solenoid valve 10. The annular portion 22a of a stationary core 20 encloses the moving core 24 for its uniform magnetic flux density to thereby attract the moving core 24 evenly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a solenoid valve.

[0002]

2. Description of the Related Art Conventionally, a movable portion to be attracted to a fixed portion is provided outside a coil, and a solenoid valve having no movable portion in the coil is disclosed in Japanese Patent Application Laid-Open Nos. 60-249777 and 61-249. The one disclosed in Japanese Patent No. 31781 is known. A solenoid valve disclosed in Japanese Patent Application Laid-Open No. 60-249777 has a movable iron piece as a movable part extending in a radial direction of the coil in one axial direction of the coil, and a rod connected to an end of the movable iron piece. The valve opens and closes the valve port.

The solenoid valve disclosed in Japanese Patent Application Laid-Open No. 61-31781 is provided with a movable core as a movable portion extending in a radial direction of the coil in one axial direction of the coil, and the movable core is a fixed core. , The other end of the movable iron core is attracted to the other magnetic pole of the fixed iron core, and the valve element attached to the movable iron core changes the opening area of the valve hole.

[0004]

However, Japanese Patent Application Laid-Open Nos. Sho 60-249777 and 61-3178.
In any of the solenoid valves disclosed in Japanese Patent Application Publication No. 1 (1994), the axial direction of the coil and the moving direction of the movable portion are parallel, the coil exists in the reciprocating direction of the movable portion, and the movable portion extends in the radial direction of the coil. The valve member is disposed at the end of the. Therefore, there is a problem that the physical size of the movable portion in the radial direction is increased.

Further, as a method of sucking the movable portion, there are disclosed a structure in which the movable portion is uniformly sucked toward the coil side and a structure in which the movable portion is sucked like a lever with one point of the movable portion as a fulcrum. In the configuration (1), there is a problem that the movable portion needs to have a certain degree of rigidity, so that the size of the movable portion increases, and the electromagnetic force needs to be increased in order to attract the enlarged movable portion.

Further, in order to achieve a desired amount of movement of the movable portion, the length of the movable portion in the radial direction of the coil is increased, and the size of the solenoid valve is increased. An object of the present invention is to provide a solenoid valve which can be easily reduced in size.

[0007]

According to the solenoid valve according to the first aspect of the present invention, the movable core disposed outside the coil reciprocates in the direction orthogonal to the axis of the coil.
It is possible to adopt a configuration in which no coil exists in the reciprocating direction of the movable portion of the solenoid valve having the movable core. Therefore, since the coil as the electromagnetic drive unit and the movable part of the electromagnetic valve including the movable core can be manufactured as a module, respectively, the assembly of the electromagnetic valve becomes easy. Further, since no movable portion is accommodated in the coil, the coil can be reduced in size. Furthermore, since a valve section can be provided at the end of the movable core in the reciprocating movement direction, it is possible to prevent the movable section including the movable core from being enlarged, and to move the movable section without increasing the size of the movable section. The amount can be increased. Therefore, it is not necessary to increase the electromagnetic force required to attract the movable part, and the electromagnetic valve can be downsized.

According to the solenoid valve of the second aspect of the present invention,
The annular portion formed on the side opposite to the support portion of one arm constituting the fixed core is arranged so as to surround the movable core, so that the magnetic flux density in the annular portion is made uniform in the circumferential direction surrounding the movable core. Can be. Therefore, there is no bias in the force for attracting the movable core, so that the movable core can smoothly reciprocate.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 shows an evaporative fuel supply system using an electromagnetic valve according to one embodiment of the present invention. The solenoid valve 10 is the solenoid valve of the present embodiment, and is used as a three-way valve in the evaporative fuel supply system shown in FIG.

The evaporative fuel supply system shown in FIG. 2 is a system for checking for a leak of evaporative fuel generated from the fuel tank 100 and the canister 110. The fuel tank 100 is connected to a canister 110 via a pipe 101. A bypass pipe 102 is connected to the pipe 101, and the solenoid valve 10 and the pressure sensor 120 are attached to the bypass pipe 102. The canister 110
It is connected to an electromagnetic valve 112 via an atmosphere opening pipe 111 and to a purge valve 113 via a pipe 104. An intake pipe 1 is provided on the side of the purge valve 113 opposite to the canister.
05 is connected.

The fuel tank 100 is maintained at a constant positive pressure by the set pressure of the internal pressure valve 103. This constant positive pressure is applied to the pressure sensor 120 via the first port 41 and the second port 42 of the solenoid valve 10, and the pressure sensor 120 checks the pressure in the fuel tank to check for leakage of fuel vapor. On the other hand, when checking for leakage on the canister side, the solenoid valve 112 is closed, and the purge valve 113 is closed when the inside of the canister reaches a constant negative pressure, thereby maintaining the inside of the canister at a constant negative pressure. This constant negative pressure is the third
The pressure is applied to the pressure sensor 120 via the entrance 43 and the second entrance 42, and the pressure inside the canister is checked by the pressure sensor 120 to check for leakage of fuel vapor.

Next, the configuration of the solenoid valve 10 will be described in detail.
As shown in FIG. 1, a first entrance 41 and a second entrance 41 are formed in the housing 11, and the third entrance 4 is formed in the cover 12.
3 are formed. Housing 11 and cover 12
Is made of resin. The first passage 41a and the second
The second flow path 42a in the entrance and the third flow path 4 in the third entrance and exit.
3a are respectively formed. A cylindrical portion 11a formed near the center of the inside of the housing 11 supports a movable core 24 to be described later in a reciprocating manner. The cylindrical portion 11
A through-hole communicating with the first flow path 41a is formed at an end of a, and a valve seat 41b on which the valve member 25 can be seated is formed around the through-hole.

As shown in FIG. 4 and FIG.
0 is the L-shaped member 21, the first plate member 22 and the second
It is made of a plate member 23 and is pressed integrally into a plate shape. The L-shaped member 21 includes an arm portion 21a and a support portion 21c, and the arm portion 21 facing the movable core 24.
an opposing portion 21b which protrudes in a cylindrical shape toward the movable core at a position a
Are formed. A third flow path 43 is provided at the center of the facing portion 21b.
A through hole communicating with the valve member b is formed, and a valve seat 43b on which the valve member 25 can be seated is formed around the through hole.

The first plate member 22 includes an annular portion 22a and a plate portion 22b, and together with the arm portion 21a, constitutes a "pair of arm portions" described in the claims. The annular portion 22a surrounds the outer periphery of the cylindrical portion 11a, and further surrounds the movable core 24. The first plate member 22 is assembled in contact with the support portion 21c.
The second plate member 23 is a plate portion 2 of the first plate member 22.
2b to reinforce the mechanical strength.

As shown in FIG. 1, the movable core 24 is disposed outside a coil 32, which will be described later, and has a cylindrical shape. The movable core 24 is supported by the cylindrical portion 11a so as to be able to reciprocate. The movable core 24 is urged in a direction away from the facing portion 21b by the urging force of a spring 26 as urging means. The reciprocating direction of the movable core 24 is orthogonal to the axis of the coil 32. The valve member 25 is a movable core 2
4 and a movable portion, and is fixed to a side of the movable core 24 opposite to the protruding portion 21b which is one end in the reciprocating movement direction. A sliding clearance 5 enough to allow fluid to flow between the outer peripheral wall of the movable core 24 and the inner peripheral wall of the cylindrical portion 11a.
Since 0 is formed, when the valve member 25 is seated on the valve seat 41b, the second flow path 42a and the third flow path 43a communicate with each other via the sliding clearance 50.

The bobbin 31 is disposed on the outer periphery of the first plate member 22 and the second plate member 23, and a coil 32 is wound around the bobbin 31. The coil 32 is arranged on one radially outer peripheral side of the movable core 24, and the axis of the coil 32 is orthogonal to the reciprocating axis of the movable core 24. When the power supply to the coil 32 is turned on, a magnetic flux flows as shown by an arrow in FIG. 3 and the movable core 24 is seated on the valve seat 43 b against the urging force of the spring 26.

Next, the operation of the solenoid valve 10 will be described. (1) When the power to the coil 32 is turned off, the movable core 24 is urged toward the valve seat 41b by the urging force of the spring 26,
The valve member 25 is seated on the valve seat 41b. At this time, the first flow path 41a is shut off, and the second flow path 42a and the third flow path 4
3a.

(2) When the energization of the coil 32 is turned on, the movable core 24 is attracted to the opposite side of the L-shaped member 21 and the valve member 25
Is seated on the valve seat 43b. At this time, the third flow path 43
a is shut off, and the first flow path 41a and the second flow path 42a communicate with each other. In the example showing the embodiment of the present invention described above, the movable core 24 is disposed outside the coil 32,
Since the movable core 24 reciprocates in a direction perpendicular to the axis of the coil 32, there is no movable portion and no fluid flow path in the coil. Therefore, the coil 3 as an electromagnetic drive unit
2 can be made smaller. Further, since the coil 32 does not exist in the reciprocating direction of the movable portion including the movable core 24 and the valve member 25, it is not necessary to increase the size of the movable core 24 to drive the valve member 25. Thus, the size of the movable core 24 can be prevented and the electromagnetic force for attracting the movable core 24 can be reduced, so that the size of the coil 32 can be reduced. Therefore, the physical size of the solenoid valve 10 can be reduced. Further, the lift amount of the valve member 25 can be increased without being limited by the occupied area of the coil 32 and without increasing the size of the movable core 24.

In this embodiment, since the annular portion 22a of the fixed core 20 surrounds the movable core 24, the coil 3 is disposed on one radially outer side of the movable core 24.
Even when the coil 2 is provided, the magnetic flux density in the annular portion 22a becomes uniform, so that the movable core 24 can be uniformly attracted to the opposing portion of the L-shaped member 21 when the coil 32 is turned on.

Furthermore, the number of members constituting the fixed core 20 is small, and the first plate member 22 is
c, the first plate member 22 and the opposite side of the arm 21a extending from the end of the support 21c.
Of the opposed portion 21b and the annular portion 22a formed on the side opposite to the support portion can be suppressed. Therefore, the force for attracting the movable core 24 is not biased, and the movable core 24 can be uniformly sucked, so that the movable core 24 can reciprocate smoothly.

Further, in this embodiment, the members constituting the solenoid valve 10 are formed separately and modularized, and are not formed by, for example, molding or insert molding when the solenoid valve 10 is assembled. . Therefore,
Since the manufacturing process of the solenoid valve 10 can be clearly classified into a member forming process and an assembling process, the manufacturing process of the solenoid valve 10 is simplified, and the number of manufacturing steps is reduced.

Further, in this embodiment, since each member constituting the fixed core 20 is formed in a plate shape, the fixed core 20 can be processed by pressing instead of cutting. Therefore, the processing of the fixed core is facilitated, and the manufacturing cost is reduced. In this embodiment, an example in which the configuration of the present invention is applied to a three-way valve has been described, but the configuration of the present invention may be applied to a two-way valve.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a solenoid valve according to an embodiment of the present invention.

FIG. 2 is a configuration diagram showing an evaporative fuel supply system using the solenoid valve of the present embodiment.

FIG. 3 is a cross-sectional view illustrating a magnetic circuit according to the present embodiment.

FIG. 4 is a side view showing a fixed core of the present embodiment.

FIG. 5 is a perspective view showing a fixed core of the present embodiment.

[Explanation of symbols]

 Reference Signs List 10 solenoid valve 11 housing 12 cover 20 fixed core 21 L-shaped member 21a arm portion 21b facing portion 21c support portion 22 first plate member (arm portion) 22a annular portion 23 second plate member (arm portion) 24 movable core 25 valve member 26 spring 31 bobbin 32 coil 41 1st doorway 42 2nd doorway 43 3rd doorway

Claims (2)

[Claims] An electromagnetic valve, wherein a magnetic circuit is formed by a movable core and a fixed core, and the energization of a coil is turned on so that the movable core is attracted to the fixed core. An electromagnetic valve disposed outside, wherein the movable core reciprocates in a direction orthogonal to an axis of the coil. 2. The fixed core is formed in a substantially U-shape including a supporting portion and a pair of arms extending from both ends of the supporting portion, and the movable core is provided on one of the arms opposite to the supporting portion. An annular portion surrounding the core; an opposite portion facing the movable core on a side opposite to the support portion of the other arm portion; the coil being wound around one of the pair of arm portions; 2. The solenoid valve according to claim 1, wherein: