JP4172419B2 - solenoid valve - Google Patents

Description

  The present invention relates to an electromagnetic valve that is operated by an electromagnetic actuator and switches a flow path.

[Conventional technology]
2. Description of the Related Art Conventionally, an electromagnetic valve that is inserted into a body or the like in which various fluid circuits are formed and switches a flow path is known. The solenoid valve includes a sleeve in which a plurality of ports communicating with various flow paths are formed, a spool that is slidably supported in the axial direction inside the sleeve, and that switches the communication state between the ports by displacing in the axial direction; And an electromagnetic actuator that applies a driving shaft force to the spool to displace the spool in the axial direction.

  A circumferential groove is formed on the outer periphery of the sleeve, and a port is opened in the groove. A filter that captures foreign substances contained in the fluid is attached to the groove and covers each port. A filter is a filter with a frame which has the filtration part which consists of metal nets, and the resin-made frame part shape | molded integrally with the filtration part, for example, and is formed in substantially C shape. The framed filter is fitted into the groove so as to surround the outer periphery of the sleeve in an annular shape, and is engaged by engaging portions provided at both ends of the frame (see, for example, Patent Document 1). ).

  However, when adopting a framed filter, it is necessary to increase the processing accuracy of the engaging portion and to perform the mounting operation with certainty in order to prevent leakage of foreign matter in the engaging portion. On the other hand, in recent years, a porous filter 100 made of a thin metal plate having no frame portion as shown in FIG. 5 has attracted attention. The porous filter 100 fulfills a filtration function by a large number of pores 101 penetrating in the thickness direction.

  As with the framed filter, the porous filter 100 is also fitted and fitted into the groove portion 103 so as to surround the outer periphery of the sleeve 102 in an annular shape as shown in FIG. At this time, the porous filter 100 is mounted with both end portions 104 and 106 overlapped (see FIGS. 5B and 5C). When a fluid pressure is applied, the outer peripheral surface 105 of the porous filter 100 at one end 104 comes into liquid-tight contact with the inner peripheral surface 107 of the porous filter 100 at the other end 106, thereby preventing leakage of foreign matter. Is done. For this reason, the malfunction regarding the engaging part at the time of employ | adopting a filter with a frame is eliminated. However, since the ring diameter of the porous filter 100 is expanded by applying the pressure of the fluid, the following another problem occurs.

[Problems with conventional technology]
That is, when the porous filter 100 is attached to the groove 103 where the output port 108 opens, the porous filter 100 is added in the direction in which the ring diameter is expanded (expanded) by the fluid, as shown in FIG. Pressed. Thereby, the distance between the outer peripheral surface 105 of the porous filter 100 and the inner peripheral surface 110 formed on the body 109 is reduced. For this reason, the area (effective filtration area) of the effective filtration part in which filtration is performed substantially will fall. And if the porous filter 100 expands until the outer peripheral surface 105 and the internal peripheral surface 110 contact, the effective filtration area will fall to the same extent as the opening area of the flow path 111 in the internal peripheral surface 110. FIG.

  Note that the same problem is expected to occur when the porous filter 100 is attached to the groove 103 where the input port 112 opens, as shown in FIG. In this case, the porous filter 100 is pressurized in the direction in which the ring diameter is reduced, and the effective filtration area is considered to be reduced by reducing the distance between the inner peripheral surface 107 of the porous filter 100 and the outer peripheral surface 113 of the groove 103. .

However, as shown in FIG. 5 (a), since both ends of the groove 103 are conventionally formed with stepped portions 114 or portions corresponding thereto, the porous filter 100 has a height higher than the effective height h of the stepped portion 114. The groove 103 cannot be approached. For this reason, even if the porous filter 100 is attached to the groove portion 103 where the input port 112 opens, a necessary effective filtration area can be ensured.
JP 2000-346006 A

  The present invention has been made to solve the above-described problems, and it is an object of the present invention to provide an electromagnetic valve capable of ensuring an effective filtration area of a porous filter attached to an output port.

[Means of Claim 1]
In the electromagnetic valve according to the first aspect, the pressing member comes into contact with at least one of the one end or the other end in the axial direction of the porous filter covering the output port from the outer peripheral side of the porous filter. The pressing member is a coil including a spiral portion wound in a spiral shape and an annular portion wound in an annular shape at both ends of the spiral portion.
Thereby, the pressing member can prevent the porous filter from being pressurized and expanded by the fluid flowing out from the output port. For this reason, it is possible to prevent the distance between the outer peripheral surface of the porous filter and the inner peripheral surface formed on the body from being reduced. As a result, the effective filtration area of the porous filter attached to the output port can be ensured.

[Means of claim 2 ]
In the electromagnetic valve according to claim 2 , the spiral portion of the coil is formed by one turn.
Thereby, the fall of the filtration efficiency in the axial direction center part of a porous filter can be suppressed to the minimum.

[Means of claim 3 ]
In the electromagnetic valve according to claim 3 , the porous filter and the pressing member are fitted in a circumferential groove formed on the outer periphery of the sleeve, and the pressing member does not protrude to the outer peripheral side from the outer peripheral surface of the sleeve. .
The inner peripheral surface of the body and the outer peripheral surface of the sleeve are processed extremely precisely so as to come into liquid-tight contact. For this reason, if the pressing member protrudes more outward than the outer peripheral surface of the sleeve, the sleeve cannot be fitted into the body. Therefore, the sleeve can be smoothly inserted into the body by preventing the pressing member from protruding outward from the outer peripheral surface of the sleeve.

  The solenoid valve of the best mode 1 is supported by a sleeve in which an output port from which a fluid flows and an output port from which the fluid flows is formed, and is slidably supported in the axial direction inside the sleeve, and is displaced in the axial direction. A spool that opens and closes the output port, an electromagnetic actuator that applies a driving axial force to the spool and displaces the spool in the axial direction, and a thin plate that covers both ends of the sleeve in an annular manner and surrounds the output port And a holding member that suppresses the porous filter from being expanded by being pressurized by the fluid flowing out from the output port by contacting at least one of the axial end and the other end of the porous filter from the outer peripheral side. With.

Even push member is a coil having a circular section wound in a ring shape on both ends of the wound spiral portion spiral shape and Nishisen portion. Further, the spiral portion is formed by one turn.
Further, the porous filter and the pressing member are fitted into a groove formed circumferentially on the outer periphery of the sleeve, and the pressing member does not protrude to the outer peripheral side from the outer peripheral surface of the sleeve.

[Configuration of Example 1]
The configuration of the electromagnetic valve 1 of Example 1 will be described with reference to FIGS. 1 to 3 (Example 1 is a reference example of the present invention) .
The solenoid valve 1 includes a body (not shown) in which a fluid circuit such as a hydraulic circuit that supplies hydraulic pressure to a transmission element of an automatic transmission and a hydraulic circuit that supplies hydraulic pressure to a variable element of an engine valve variable timing device is formed. And the flow path is switched.

  As shown in FIGS. 1A and 1B, the solenoid valve 1 includes a sleeve 3 in which a plurality of ports 2 communicating with various flow paths constituting a fluid circuit are formed, and an axial direction within the sleeve 3. A spool (not shown) that is slidably supported and switches the communication state between the ports 2 by being displaced in the axial direction, and an electromagnetic actuator 4 that applies a driving axial force to the spool to displace the spool in the axial direction. The porous filter 5 that covers each port 2 and captures foreign matters contained in the fluid, and the pressing member 7 that suppresses the diameter expansion of the porous filter 5 that covers the output port 6 are provided.

  The sleeve 3 has a plurality of ports 2 such as an input port (not shown) through which fluid flows into the sleeve 3 from an external flow path, and an output port 6 through which fluid flows from the inside of the sleeve 3 to the external flow path. Is formed. The sleeve 3 is fitted into the body so that a flow path that opens to the inner peripheral surface of the body and a port 2 that matches the flow path communicate with each other. Further, a groove 11 is formed on the outer periphery of the sleeve 3 in a circumferential shape, and each port 2 is opened in the groove 11. Furthermore, step portions 12 that sandwich the porous filter 5 together with the pressing member 7 are formed at both axial ends of the groove portion 11.

  As shown in FIGS. 1B and 1C, the porous filter 5 is a rectangular metal thin plate in which a large number of pores 14 are formed in the thickness direction. Both ends of the porous filter 5 form overlapping portions 15 and 16 that are overlapped with each other. The porous filter 5 is deformed into a substantially C shape so that the overlapping portions 15 and 16 are overlapped, and the porous filter 5 is fitted into the groove portion 11 so as to surround the outer periphery of the sleeve 3 in an annular shape. Note that the axial width of the porous filter 5 is substantially the same as the width of the groove 11, and the porous filter 5 can be easily fitted into the groove 11.

  The pressing member 7 is mounted so as to surround the porous filter 5 fitted in the groove 11 from the outer peripheral side. As shown in the development view of FIG. 2, the pressing member 7 has a substantially rectangular shape, and includes two crosspieces 18 in the long side direction, an auxiliary crosspiece 19 that bridges the two crosspieces 18 in the short side direction, and two crosspieces 18. And two engaging portions 20 that engage with each other when enclosing the porous filter 5. The pressing member 7 is formed in a substantially C shape, and the engaging portions 20 are engaged with each other as shown in FIG.

  The crosspiece 18 is arrange | positioned so that the axial direction both ends of the porous filter 5 may be pinched | interposed with the step part 12, as shown in FIG.1 (b), (c). Further, the auxiliary bar 19 is cross-linked so as to form a predetermined gap with the porous filter 5. Thereby, the fall of the filtration efficiency accompanying attachment of the auxiliary crosspiece 19 can be prevented. Further, the pressing member 7 is sized so as not to protrude to the outer peripheral side from the outer peripheral surface 22 of the sleeve 3 in a state of being fitted into the groove portion 11 together with the porous filter 5.

[Operation of Example 1]
The operation of the solenoid valve 1 according to the first embodiment will be described.
When the spool is driven in the axial direction by the electromagnetic actuator 4 and fluid begins to flow out from the output port 6, the porous filter 5 is pressurized in the direction of expanding the diameter. Accordingly, the outer peripheral surface 24 of the porous filter 5 in the one overlapping portion 15 comes into liquid-tight contact with the inner peripheral surface 25 of the porous filter 5 in the other overlapping portion 16. Further, the pressing member 7 contacts the outer peripheral surface 24 from the outer peripheral side. Thereby, it is suppressed that the porous filter 5 expands in diameter, maintaining the liquid tightness in the overlapping parts 15 and 16.

[Effect of Example 1]
In the solenoid valve 1 of the first embodiment, the pressing member 7 contacts the outer peripheral surface 24 from the outer peripheral side of the porous filter 5 that covers the output port 6.
Thereby, the holding member 7 can prevent the porous filter 5 from being pressurized and expanded in diameter by the fluid flowing out from the output port 6. For this reason, it is possible to prevent the distance between the outer peripheral surface 24 of the porous filter 5 and the inner peripheral surface of the body from being reduced. As a result, the effective filtration area of the porous filter 5 attached to the output port 6 can be ensured.

In the electromagnetic valve 1 according to the first embodiment, the two crosspieces 18 surround both ends of the porous filter 5 in the annular shape as the pressing member 7.
As a result, it is possible to reliably prevent the diameter of the porous filter 5 from being increased and to perform filtration effectively at the central portion in the axial direction of the porous filter 5.

In the electromagnetic valve 1 according to the first embodiment, two crosspieces 18 disposed at both axial ends of the porous filter 5 are bridged by auxiliary crosspieces 19.
As a result, it is possible to prevent the two crosspieces 18 from moving from both axial ends of the porous filter 5 to the central portion in the axial direction. As a result, it can prevent that the filtration efficiency in the axial center part of the porous filter 5 falls.

In the solenoid valve 1 according to the first embodiment, the porous filter 5 and the pressing member 7 are fitted in a circumferential groove portion 11 formed on the outer periphery of the sleeve 3, and the pressing member 7 is more than the outer peripheral surface 22 of the sleeve 3. It does not protrude to the outer periphery.
The inner peripheral surface of the body and the outer peripheral surface 22 of the sleeve 3 are processed extremely precisely to maintain liquid tightness. For this reason, if the crosspiece 18 protrudes from the outer peripheral surface 22 of the sleeve 3 to the outer peripheral side, the sleeve 3 cannot be inserted into the body. Therefore, the sleeve 3 can be smoothly inserted into the body by preventing the crosspiece 18 from projecting to the outer peripheral side of the outer peripheral surface 22.

[Configuration of Example 2]
The configuration of the solenoid valve 1 of the second embodiment will be described with reference to FIG. 4 (the second embodiment is an application example of the present invention) .
The pressing member 7 of the second embodiment is a coil 28. The coil 28 includes a spiral portion 29 wound in a spiral shape and an annular portion 30 wound in an annular shape at both ends of the spiral portion 29. The coil 28 has substantially the same length as the width of the porous filter 5 in the axial direction, and the annular portion 30 surrounds both ends in the axial direction of the porous filter 5 in a C shape, and the porous filter 5 together with the step portion 12 It arrange | positions so that it may pinch | interpose. Further, the coil 28 is sized so as not to protrude outward from the outer peripheral surface 22 of the sleeve 3.

[Effect of Example 2]
In the electromagnetic valve 1 according to the second embodiment, the coil 28 as the pressing member 7 prevents the porous filter 5 from expanding in diameter.
Thereby, the diameter expansion of the porous filter 5 can be prevented reliably.

In the solenoid valve 1 of the second embodiment, the spiral portion 29 of the coil 28 is formed by one turn.
Thereby, the fall of the filtration efficiency in the axial direction center part of the porous filter 5 can be suppressed to the minimum.

[Modification ]
In the real施例2, the spiral portion 29 had to Volume 1 in consideration of the filtration efficiency may be increased the number of turns in two or more volumes.

(A) is a side view of the solenoid valve before mounting the porous filter, (b) is an explanatory view showing a mounting state of the porous filter and the pressing member, and (c) is a sectional view of the solenoid valve after mounting the porous filter. (Example 1). (A) is a top view when a pressing member is developed, (b) is a side view when a pressing member is developed (Example 1). (Example 1) which is a perspective view of a pressing member. (A) is explanatory drawing which shows the mounting state of a porous filter and a pressing member, (b) is sectional drawing of the solenoid valve after porous filter mounting (Example 2). (A) is sectional drawing which shows the state which attached the solenoid valve to the body, (b) is explanatory drawing which shows the state which attached the porous filter to the output port, (c) is attached to the input port of the porous filter It is explanatory drawing which shows the state which carried out (conventional example).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Solenoid valve 2 Port 3 Sleeve 4 Electromagnetic actuator 5 Porous filter 6 Output port 7 Holding member 11 Groove part 18 Crosspiece 19 Auxiliary crosspiece 22 Outer peripheral surface 28 Coil 29 Spiral part 30 Ring part

Claims (3)

A sleeve in which an output port from which fluid flows in and fluid flows out is formed;
A spool that is slidably supported in the axial direction inside the sleeve, and that opens and closes the output port by being displaced in the axial direction;
An electromagnetic actuator that applies a driving axial force to the spool to displace the spool in the axial direction;
A thin plate-like porous filter covering the output port, with both ends overlapped and annularly surrounding the outer periphery of the sleeve;
A pressing member that prevents the porous filter from being expanded by being pressurized by the fluid flowing out from the output port by contacting at least one of the axial end and the other end of the porous filter from the outer peripheral side. ,
The solenoid valve according to claim 1, wherein the pressing member is a coil including a spiral wound part in a spiral shape and an annular part wound in an annular shape at both ends of the spiral part . The solenoid valve according to claim 1,
The electromagnetic valve according to claim 1, wherein the spiral portion is formed by one turn . The solenoid valve according to claim 1 or 2,
The porous filter and the pressing member are fitted into a groove formed circumferentially on the outer periphery of the sleeve,
The electromagnetic valve according to claim 1, wherein the pressing member does not protrude from the outer peripheral surface of the sleeve to the outer peripheral side .

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