JP2008082527A - Solenoid valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small-size and high-performance solenoid valve 1 capable of easily managing the machining accuracy and assembling accuracy of a sliding part, superior in productivity with one-way assembly and less in cost increase. <P>SOLUTION: The solenoid valve 1 comprises a first core member 11 having a cylinder part 10 passed therethrough in the axial direction and an assembling flange part 17 on one side thereof, a second core member 12 provided separately from the first core member 11, and having a cylinder part 20 coaxially stored on one side of the cylinder part 10 and provided with a suction face 22 on the other side and an assembling flange part 18, and a yoke 16 for holding a non-magnetic member 30 having a predetermined thickness and having an assembling flange part 31 on one side and a cylinder part 32 on the other side for storing a plunger 6, between the first core member 11 and the second core member 12 so that the cylinder part 32 of the non-magnetic member 30 stores the plunger 6 to be reciprocative in opposition to the suction face 22 and the flange parts are encircled in sequence from one side and caulked and joined to a flange part 8a of a sleeve 8. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electromagnetic valve in which a valve element is driven by a magnetic force from a solenoid.

  Conventionally, the flow path is switched and opened and closed, or the fluid (hydraulic oil) is controlled to a predetermined flow rate and pressure using an electromagnetic valve whose valve element is driven by a magnetic force from a solenoid. This solenoid valve is used in, for example, control of the hydraulic pressure of hydraulic oil supplied to a hydraulic control device of an automatic transmission for automobiles, a variable valve timing device that varies the advance phase of a camshaft of an internal combustion engine by hydraulic pressure, and the like. .

[First prior art]
For example, as shown in FIG. 3, a conventional solenoid valve 100 includes a valve body (spool) 110 that is accommodated in a sleeve 111 having a plurality of oil passages (ports) 107 to open and close the port 107, and the spool 110. A valve body 120 formed of a spring 119 that biases the other side; a mover (plunger) 102 that is disposed on the other side and can be displaced to one side in the axial direction by receiving a magnetic force from the solenoid 101; A magnetic circuit is configured between a fixed core (core stator) 104 provided with a plunger accommodating portion 103 that slidably accommodates the plunger 102 and a yoke 114 that accommodates the solenoid 101 therein, and the spool 110 is driven to one side. Drive unit 105.

  A bearing portion 112 that slidably supports a shaft 106 that interlocks the plunger 102 and the spool 110 is formed on one side in the axial direction of the plunger housing portion 103. A suction surface 108 is formed on the other end surface of the bearing portion 112, and a magnetic circuit is formed between the inner peripheral side of the solenoid 101 and the one end surface 109 of the plunger 102. Since the one end surface 109 of the plunger 102 and the suction surface 108 of the bearing portion 112 are arranged to have a finite gap, the suction force by the magnetic force from the solenoid 101 is increased, and the displacement amount of the plunger 102 is increased. Regardless of, it can be maintained at a substantially constant value. As a result, the control performance such as hydraulic pressure due to the displacement of the spool 110 can be stabilized (for example, see Patent Document 1).

  In order to switch the flow path and control the hydraulic pressure of the hydraulic oil reliably and stably, the inner peripheral surface of the plunger housing portion 103 is processed as accurately as possible so that the plunger 102 can be displaced precisely. There is a need. However, since the suction surface 108 of the bearing portion 112 is formed at the tip of the inner peripheral surface, it is difficult to perform high-precision processing such as burnishing on the inner peripheral surface in the vicinity of the suction surface 108, The processing accuracy of the inner peripheral surface cannot be increased. Therefore, the plunger housing portion 103 and the bearing portion 112 are not integrally formed, but the first core member 104A having the plunger housing portion 103 and the first core member 104A are separate from each other, and the plunger housing portion 103 The core stator 104 is formed by fitting with the second core member 104B which is fixed to one side and constitutes the bearing portion 112 (see Patent Document 2).

  Thus, before the second core member 104B is fitted and fixed to the first core member 104A, the inner peripheral surface of the plunger housing portion 103 can be subjected to high-precision processing such as burnishing, and the plunger 102 can be precisely processed. Displacement is possible. Furthermore, since the suction surface 108 of the second core member 104B and the one end surface 109 of the plunger 102 can be opposed to each other on the inner peripheral side of the solenoid 101, the suction force by the magnetic force between the plunger 102 and the core stator 104 is increased. In addition, it can be set to a substantially constant value regardless of the displacement amount of the plunger 102, and stable control performance can be ensured.

  In addition, since the first core member 104A and the second core member 104B are separated, the second core member 104B alone is attached to the sliding surface of the bearing portion 112 that slidably supports the shaft 106. Since the hardening process and the groove of the breathing hole 113 can be easily provided on the outer peripheral surface, the complexity of the process of providing the breathing hole 113 can be reduced and the processing efficiency can be improved.

  As described above, the first prior art has the advantageous effects as described above. However, the first core member 104A and the second core member 104B are separated from each other and precision finished with each other. Since the core stator 104 is formed by performing fitting and fixing, there is a concern that the number of parts increases and the trouble of accuracy control and the increase in the number of fitting assembly steps reduce productivity and increase costs.

[Second prior art]
In a solenoid valve that can be reduced in size, it is possible to increase the attraction force due to the magnetic force between the plunger 102 and the core stator 104 and to maintain a substantially constant value regardless of the displacement amount of the plunger 102 and to ensure stable control performance. If a gap (referred to as a side gap) formed radially between the inner circumferential side of the plunger housing portion 103 and the outer circumferential side of the plunger 102 is eccentric with respect to the plunger housing portion 103 when the plunger 102 reciprocates, As a result, a force (referred to as a side force) that attracts the plunger 102 in the radial direction of the plunger housing portion 103 increases, and a sliding resistance generated between the plunger 102 and the plunger housing portion 103 increases. .

  When the current value supplied to the solenoid 101 is increased, the magnetic force increases, the side force increases, and the sliding resistance also increases. Accordingly, the hysteresis of the reciprocating position of the plunger 102 increases with respect to the current value in the increasing / decreasing direction of the current supplied to the solenoid 101. When an electromagnetic valve having a large hysteresis is used in a hydraulic control device or the like, there arises a problem that the flow rate or hydraulic pressure of the hydraulic oil is different between the increasing direction and decreasing direction of the current with respect to the same current value, that is, the hydraulic pressure cannot be controlled with high accuracy.

  For this reason, a non-magnetic material is provided on the inner peripheral side of the plunger housing portion 103 and on the outer peripheral side of the plunger 102 as a solenoid valve that has a small hysteresis in the reciprocating position of the plunger 102 relative to the current value supplied to the solenoid 101 and can be reduced in size. Covering with resin coating or nickel / phosphorus (NiP) plating, etc., the eccentricity of the plunger 102 with respect to the plunger housing portion 103 is suppressed to 20% or more and 60% or less, and the current value supplied to the solenoid 101 is increased. An electromagnetic valve having a structure in which the attracting surface 108 is magnetically saturated when it reaches about 50% of the maximum current value is disclosed (see Patent Document 3).

  An example in which the solenoid valve disclosed in Patent Document 3 is applied to control the hydraulic pressure of hydraulic fluid supplied to a hydraulic control device of an automatic transmission for an automobile is shown. Also in the solenoid valve disclosed in Patent Document 3, the spool 110 reciprocally moves together with the plunger 102 and the magnetic circuit such as the solenoid 101 that generates a magnetic attractive force by supplying current, thereby controlling the hydraulic pressure of the hydraulic oil. The type hydraulic control valve is the same as the electromagnetic valve described in the first prior art in the configuration and operation. Accordingly, substantially the same components as those in the first conventional example are denoted by the same reference numerals, and detailed description of the configurations is omitted.

  In such a solenoid valve, even if the current value supplied to the solenoid 101 is increased to 50% or more of the maximum current value, the side force is suppressed from increasing. Even if it is eccentric, the upper limit value of the side force can be reduced, and the upper limit value of the sliding resistance acting between the plunger accommodating portion 103 and the plunger 102 can be reduced. The difference between the reciprocating positions of the plunger 102 and the spool 110 in terms of values, that is, the value of the hydraulic pressure is small, and the hysteresis is small. Therefore, it is possible to control the hydraulic pressure with high accuracy by adjusting the current value.

  As described above, although the second conventional technique has the effects as described above, in order to suppress the eccentricity to 20% or more and 60% or less, the inner circumference of the plunger housing portion 103 can be reduced. When the magnetic gap between the side and the outer peripheral side of the plunger 102 is 100 μm, the sum of the thicknesses of the nonmagnetic layers on the inner peripheral side of the plunger housing portion 103 and the outer peripheral side of the plunger 102 is suppressed to 40 μm or more and 80 μm or less. In order to process the non-magnetic layer by resin coating or NiP plating, etc., the processing thickness is excessive, the processing time becomes longer, the productivity decreases, and the amount of expensive material used also increases. There was concern that the cost would be high.

[Third prior art]
As described above, the electromagnetic valve disclosed in Patent Document 3 as the second prior art suppresses the eccentricity of the plunger 102 with respect to the plunger accommodating portion 103 to 20% or more and 60% or less, and further supplies the solenoid 101 with it. The electromagnetic valve has a structure in which the suction surface 108 is magnetically saturated when the current value increases and reaches approximately 50% of the maximum current value. However, the magnetic saturation characteristic and the eccentricity 60% or less suppression characteristic do not need to be simultaneously established, and either the magnetic saturation characteristic or the eccentricity 60% or less suppression characteristic may be realized, and the plunger is accommodated. A nonmagnetic layer is preferably processed on both the portion 103 and the plunger 102, but a nonmagnetic layer of 40 μm or more and 80 μm or less may be processed on only one of them.

  Thus, as a second conventional technique, an electromagnetic wave that has been solved by adopting a SUS cup made of a non-magnetic material has been solved by the use of a SUS cup made of a non-magnetic material, because the processing thickness of the non-magnetic layer of the electromagnetic valve disclosed in Patent Document 3 is excessive. A valve is disclosed (see Patent Document 4). Here, the SUS cup is formed of a nonmagnetic material such as stainless steel (SUS), and has a bottomed cylindrical portion as a cylindrical portion and a flange portion as a connecting portion, and is formed in a cup shape. It is a member.

  The electromagnetic valve disclosed by patent document 4 has shown the example applied to the hydraulic control valve of the valve variable timing apparatus of an internal combustion engine. Also in the solenoid valve disclosed in Patent Document 4, when the spool 110 reciprocates together with the magnetic circuit such as the solenoid 101 and the plunger 102 that generate a magnetic attractive force by supplying an electric current, the flow path of the hydraulic oil can be switched. The spool type hydraulic control valve that adjusts the flow rate is the same as the electromagnetic valve described in the first and second prior arts in terms of configuration and action. Accordingly, substantially the same components as those in the first conventional example are denoted by the same reference numerals, and detailed description of the configurations is omitted.

  However, the difference is that a SUS cup-shaped nonmagnetic member formed of a nonmagnetic material such as stainless steel (SUS) is disposed inside the core stator 104. The nonmagnetic member covers the other end (flange portion) opening of the sleeve 111, and the bottom side of the bottomed cylindrical portion covers one side of the plunger 102 in the reciprocating direction. Further, the bottomed cylindrical portion covers the suction surface 108 of the core stator 104. The flange portion of the nonmagnetic member is sandwiched between the flange portion of the core stator 104 and the flange portion of the sleeve 111, and each flange portion is liquid-tightly connected by caulking as a fastening means of the yoke 114. A solenoid valve is formed.

  When a current is supplied to the solenoid 101, the plunger 102 is attracted toward one side, that is, toward the suction surface 108 against the biasing force of the biasing means. On the other hand, the spool 110 that is interlocked in the axial direction via the plunger 102 and the shaft 106 moves in the sleeve 111 in the same manner, causing communication and blocking of the port 107, and switching the flow of hydraulic oil.

  The position of the spool 110 is determined by the balance between the magnetic attractive force acting on the plunger 102 and the biasing force of the biasing means. Since the current value supplied to the solenoid 101 is proportional to the generated magnetic force, the position of the spool 110 can be linearly controlled by controlling the current value supplied to the solenoid 101. As a result, the amount of hydraulic oil supplied to or discharged from the control device is easily and accurately controlled by the position of the spool 110, that is, the current value. At this time, the hydraulic oil leaking to the plunger 102 side is prevented from leaking to the outside of the nonmagnetic member, for example, the solenoid 101 side by the nonmagnetic member. At the same time, an appropriate side gap is maintained by a non-magnetic member having a predetermined thickness, and the side force acting on the plunger 102 is reduced. Therefore, both the plunger 102 and the spool 110 can move with high accuracy, and stable flow rate control is possible. Become.

  However, the SUS cup-shaped non-magnetic member accommodates the plunger 102 inside the bottomed cylindrical portion, covers the suction surface 108 of the core stator 104 outside, and exhibits a predetermined side gap to realize the reciprocating movement of the plunger 102. However, it may be difficult to set the opposing suction surfaces 108 for increasing the suction force described in the first prior art. Therefore, Patent Document 4 adopts a stepped SUS cup-shaped nonmagnetic member, accommodates the plunger 102 inside the small diameter cylindrical portion of the stepped SUS cup, covers the inner cylinder of the yoke 114 on the outside, Further, the cylindrical portion of the core stator 104 is accommodated inside the large diameter cylindrical portion of the stepped SUS cup. One end of the cylindrical portion of the core stator 104 is a flange portion, and the other end is a suction surface 108 for increasing a suction force. An example is shown which is arranged with And the solenoid 101 molded with resin is covered outside the large-diameter cylindrical portion of the stepped SUS cup, and the solenoid 101 is accommodated in the outer cylinder of the yoke 114 formed in a double cylinder shape. Is disclosed.

  In this solenoid valve, the large diameter cylindrical portion of the stepped SUS cup-shaped non-magnetic member covers the opening of the flange portion of the sleeve 111 as a housing, and the stepped SUS cup-shaped flange portion is the flange portion of the sleeve 111. It is connected by caulking. Accordingly, it is possible to prevent the hydraulic oil leaking to the plunger 102 side from leaking to the outside of the cup-shaped member, for example, the solenoid 101 side. Furthermore, since the plunger 102 is directly supported by the stepped SUS cup-shaped non-magnetic member, the plunger 102 is not misaligned, and it is necessary to increase the gap to absorb the misalignment as in the prior art. Therefore, the magnetic circuit, that is, the driving unit 105 can be downsized. Further, since the side gap formed between the inner cylinder of the yoke 114 and the plunger 102 can be reduced, the magnetic attraction force does not decrease even if the size is reduced.

As described above, although the third prior art has the advantageous effects described above, since the plunger 102 is accommodated in the inner cylinder of the yoke 114 via the cup-shaped member, the yoke 114 is A double cylinder structure having an inner cylinder and an outer cylinder is required, and in order to ensure the coaxiality of the inner cylinder and the outer cylinder, there is a concern that precision manufacturing by a large-scale press facility or the like is required and the cost is increased. Also in the assembly of the solenoid valve, the annular solenoid 101 is inserted between the outer cylinder and the inner cylinder of the yoke 114 having a double cylinder structure, and the inner peripheral surface of the inserted solenoid 101 and the inner cylinder of the yoke 114 are also inserted. Therefore, it is necessary to manage the shape accuracy of the stepped SUS cap that is simultaneously fitted to the inner peripheral surface, and there is a concern that the shape of the stepped structure is complicated and the cost is increased. In addition, one-way assembly is difficult, and assembly productivity may be reduced.
JP 2001-227669 A JP 2005-214236 A JP 2002-222710 A Japanese Patent Laid-Open No. 2001-18779

  The present invention has been made in view of the problems of the above-mentioned plurality of conventional techniques. The processing accuracy and assembly accuracy management of the sliding portion is simple, one-way assembly is possible, productivity is high, and cost is high. The purpose is to provide a small, high-performance solenoid valve with reduced noise.

[Means of Claim 1]
The solenoid valve adopting the means of claim 1 is a core stator that forms a magnetic circuit with the plunger, and includes a cylindrical portion penetrating in the axial direction, and is caulked and fixed to the other end of the sleeve on one side of the cylindrical portion. The first core member having a flange portion and the first core member are separate from each other and have a cylindrical portion that is accommodated coaxially on one side of the cylindrical portion of the first core member, and the other side of the cylindrical portion Is provided between the first core member and the second core member, the second core member having a suction surface for sucking the plunger and having a flange portion that is caulked and fixed to the other end of the sleeve on one side. A flange portion for assembly on one side, a cylinder portion accommodated in the cylinder portion of the first core member on the other side, and a predetermined gap on the other side of the cylinder portion. The plunger is accommodated in a reciprocating manner, and the suction side of the cylindrical portion of the second core member is plugged on one side. Characterized in that it comprises a non-magnetic member disposed so as to face the jaws, and a yoke that accommodates solenoids, sequentially surrounds each flange portion from one side, and is caulked with the other end portion of the sleeve. Yes.

  Thereby, since it can divide | segment into a 1st and 2nd core member and a 2nd core member can be coaxially inserted inside a 1st core member, the suction surface which is the other end of a 2nd core member is made into a 1st core member It is easy to place it facing one end of the plunger accommodated so as to be able to reciprocate, enhances the attractive force due to the magnetic force between the plunger and the core stator, and is substantially constant regardless of the displacement amount of the plunger Thus, stable control performance can be ensured, and a small and high performance solenoid valve can be realized.

  Further, a nonmagnetic member having a predetermined thickness is sandwiched between the inner periphery of the first core member and the outer periphery of the second core member, and the plunger is reciprocally accommodated on the inner periphery side of the nonmagnetic member. Therefore, the magnetic gap between the plunger and the core stator can be reduced to the thickness of the nonmagnetic member, and the attractive force of the plunger can be easily increased. Thereby, a small high-performance solenoid valve can be realized. Also, by reducing the thickness of the nonmagnetic member, the eccentricity of the plunger relative to the core stator can be suppressed to 20% or more and 60% or less without processing a large amount of resin coating or NiP plating as in the past. Therefore, the occurrence of hysteresis can be easily reduced. Thereby, while improving the linear control performance by the increase / decrease in electric current value, productivity can improve and the small high performance solenoid valve which suppressed the high cost is realizable.

  Furthermore, each of the first and second core members and the non-magnetic member has a flange portion on one side and is closely fixed by caulking with a yoke that sequentially surrounds from one side. Assembling accuracy management becomes simple and one-way coaxial assembling becomes possible, productivity is improved and high cost can be suppressed.

[Means of claim 2]
In the solenoid valve adopting the means of claim 2, a plunger having a nonmagnetic material covering portion on a reciprocating sliding surface, and reciprocating together with the plunger, being accommodated in the sleeve, A spool that controls the flow rate or pressure of the fluid by opening and closing, a biasing means that biases the plunger to the other side in the reciprocating direction, and a solenoid that generates a magnetic force to attract the plunger to one side in the reciprocating direction; A core stator that forms a magnetic circuit with the plunger, and a predetermined distance in the reciprocating direction of the plunger between the cylindrical portion that covers the outer peripheral side surface of the plunger, the flange portion that is caulked and fixed to the other end of the sleeve, and the cylindrical portion A sleeve having a first core member having a gap and a suction surface for sucking a plunger on the other side in the reciprocating direction; and being accommodated coaxially in a cylindrical portion of the first core member; A second core member having a flange portion that is caulked and fixed to the other end, and a reciprocation with a plunger facing the other side of the cylindrical portion of the first core member and a suction surface on the other side of the cylindrical portion of the second core member It is characterized by comprising a yoke that is movably accommodated, a solenoid is accommodated, and each flange portion is sequentially surrounded from one side to be caulked with the other end portion of the sleeve.

  According to this, the only difference from the solenoid valve adopting the means of claim 1 is whether or not the nonmagnetic member is disposed in the core stator, and the nonmagnetic member is disposed to set a suitable side gap. Is substantially realized by providing the plunger with a coating portion of a non-magnetic material having a predetermined thickness. Thus, the same actions and effects as in claim 1 can be obtained, and in particular, the number of parts to be assembled can be reduced and the number of assembling steps can be reduced. Can be reduced, productivity can be improved, and a small high-performance solenoid valve can be realized at a low cost.

  The best embodiment of the present invention includes a first core member having a cylindrical portion penetrating in the axial direction and having a flange portion for assembly on one side thereof, and the first core member is a separate body. A second core member having a flange portion that is coaxially accommodated on one side of the tube portion of the first core member and has a flange portion that is fixed in close contact with the flange portion of the first core member; A cylindrical portion having a predetermined thickness between the member and the second core member, accommodated in the cylindrical portion of the first core member, and a flange portion for assembly on one side and a plunger on the other side A solenoid that sandwiches the non-magnetic member and is disposed outside the cylindrical portion of the first core member to generate a magnetic force between the plunger and the other side suction surface of the second core member, and contains the solenoid, Enclose each flange part sequentially from one side and closely contact the other end part of the sleeve A yoke for closing coupling, the spool is displaced in the axial direction of the drive of the plunger in conjunction through the shaft, an electromagnetic valve comprising a.

[Configuration of Example 1]
The solenoid valve of Example 1 is demonstrated based on FIG. FIG. 1 is an axial sectional view of a solenoid valve in the present embodiment. The solenoid valve 1 opens and closes the flow path and adjusts the flow rate and pressure of hydraulic oil by driving the spool 3 with the magnetic force from the solenoid 2. The electromagnetic valve 1 is used for controlling hydraulic pressure in a hydraulic control device for an automatic transmission for automobiles, for example.

  As shown in FIG. 1, the electromagnetic valve 1 is arranged on the other side with a valve body portion 4 in which a spool 3 that opens and closes a flow path is accommodated, and the spool 3 is moved by using magnetic force from the solenoid 2. The driving unit 5 is driven. In the electromagnetic valve 1 having the rod-like shape of the present embodiment, the axial valve body 4 side is referred to as one side, the drive unit 5 side is referred to as the other side, and the axial positional relationship follows this. Shall.

  The valve body 4 accommodates a spool 3 having a different diameter step structure which is displaced in the axial direction in conjunction with a plunger 6 which will be described later, and the spool 3 is slidable in the axial direction, and also has a hydraulic oil inlet or outlet. And a spring 8 for urging the spool 3 to the other side.

The drive unit 5 includes a yoke 16 as a stator, a core stator 15, a solenoid 2 and a nonmagnetic member 30 formed by molding a coil around a cylindrical bobbin, and a plunger 6 as a mover.
The yoke 16, the core stator 15 and the plunger 6 constitute a magnetic circuit that flows (circulates) the magnetic flux excited in the solenoid 2 by energization, and is made of a magnetic material.

  The yoke 16 is a cylindrical hollow cylinder having an opening on one side and a bottom on the other side. The opening cylinder portion on one side surrounds a core stator 15 and a nonmagnetic member 30 which will be described later and is caulked and coupled to the sleeve 8. For this reason, a caulking portion 16a for stealing meat is provided. Further, the bottomed cylindrical portion on the other side is provided with a step to form a small-diameter cylindrical portion, which is fitted to the cylindrical portion 10 of the core stator 15 and also serves as a core ring 16b as a magnetic circuit.

  The core stator 15 is composed of two core members, includes a cylindrical portion 10 that is penetrated in the axial direction, and includes a first core member 11 having a flange portion 17 for assembly on one side thereof, and the first core member 11. And a second portion having a flange portion 18 that is tightly fixed to the cylindrical portion 20 and the flange portion 17 that are coaxially accommodated on the inner circumference of one side of the cylindrical portion 10 of the first core member 11. It consists of a core member 12.

  The cylindrical portion 10 of the first core member 11 has a plunger accommodating portion 14 that accommodates the plunger 6 in a reciprocating manner, and a magnetic flux in the plunger 6 to generate a large force that attracts the plunger 6 to one side in the reciprocating direction. The plunger accommodating portion 14 is formed with a thin portion 19 as a magnetic resistance portion that makes it difficult for the magnetic flux to flow. Here, the surplus thickness of the thin portion 19 is set so as to be sufficiently large in magnetic resistance, but in this embodiment, as will be described later, when the maximum current value supplied to the solenoid 2 becomes approximately 50%, the second thickness is set. The surplus thickness is determined in consideration of the shape being set so that the suction surface 22 provided on the core member 12 is saturated with magnetic flux.

  Similarly, the second core member 12 includes a cylindrical portion 20 penetrating in the axial direction, and the outer peripheral side of the cylindrical portion 20 is a cylindrical shape that can be coaxially fitted to the inner periphery of the first core member 11. A bearing portion 21 that accommodates the shaft 13 in a reciprocating manner is formed on the circumferential side, and a suction surface 22 for generating a force that attracts the plunger 6 to the one side in the reciprocating direction is formed on the other side in the axial direction. Yes. When the second core member 12 is fitted coaxially with the first core member 11 to form the core stator 15, the length is such that the suction surface 22 reaches the set position of the thin portion 19 of the first core member 11. Also, as will be described later, the other end of the cylindrical portion 20 is tapered toward the axis so that the suction surface 22 is saturated with magnetic flux when the maximum current value supplied to the solenoid 2 reaches about 50%. The processing has been adjusted.

  The bearing portion 21 of the cylindrical portion 20 of the second core member 12 supports the shaft 13 so as to be slidable in the axial direction, and a finite gap is formed on the sliding surface between the bearing portion 21 and the shaft 13. The communication of air or hydraulic oil accompanying the displacement of the plunger 6 is ensured.

  Furthermore, in this embodiment, a nonmagnetic member 30 formed of a nonmagnetic material such as stainless steel and having a predetermined thickness is disposed between the first core member 11 and the second core member 12. . The nonmagnetic member 30 includes a cylindrical portion 32 penetrating in the axial direction, and has a flange portion 31 for assembly on one side thereof. The cylindrical portion 32 has a length that fits over the inner periphery of the first core member 11 and covers substantially the entire region of the inner peripheral surface of the first core member 11. A smooth and accurate plunger accommodating portion 34 is provided in a region (part) corresponding to the plunger accommodating portion 14 of the first core member 11 on the other axial side of the inner peripheral surface of the cylindrical portion 32. The plunger accommodating portion 34 has a predetermined gap so that the plunger 6 can be reciprocally moved. Further, one side in the axial direction of the cylindrical portion 32 is fitted to cover the entire cylindrical portion 20 of the second core member 12.

  Further, the nonmagnetic member 30 can be molded with a nonmagnetic material or can be integrally formed with the flange portion 31 and the cylindrical portion 32 by pressing, and the thickness of the cylindrical portion 32 can be set freely, and in addition, the dimensional accuracy is also good. . The thickness of the nonmagnetic material forming the cylindrical portion 32 of the nonmagnetic member 30 determines the radial magnetic gap between the plunger 6 accommodated in the plunger accommodating portion 34 and the core stator 15. Since it is easy to reduce the magnetic gap by reducing the thickness of the cylindrical portion 32, the attractive force of the plunger 6 can be easily increased.

  Further, the eccentricity of the plunger 6 with respect to the core stator 15 is 20% or more even when the processing thickness of the nonmagnetic material coating or NiP plating or the like to cover the outer peripheral side surface of the plunger 6 to be described later is reduced. , 60% or less, which makes it difficult for the plunger 6 to be eccentric with respect to the plunger housing portion 34. Accordingly, the side gap is reduced due to the eccentricity, the magnetic flux flowing in the radial direction is increased, the side force is increased, the sliding resistance is increased, and the plunger 6 is prevented from sliding smoothly.

  On the other hand, even if the current value to be supplied exceeds approximately 50% of the maximum current value, the magnetic flux density of the plunger 6 and the plunger housing portion 14 increases uniformly, and the magnetic saturation occurs up to the maximum current value. It is configured so that there is no. Therefore, the current value for energizing the solenoid 2 increases, the current value increases up to about 50%, the magnetic flux density at each part increases, and the attractive force increases. However, since the current value is as low as about 50%, the side force is not large. If the current value exceeds approximately 50%, the magnetic flux density of the plunger 6 and the plunger housing portion 14 can be increased. Therefore, even if the plunger 6 is eccentric with respect to the plunger housing portion 14, the plunger housing portion 14 and the plunger 6 The amount of increase of the magnetic flux flowing in the radial direction between the two decreases. Thereby, it is suppressed that side force increases locally.

  In other words, when the sliding resistance of the plunger 6 is increased or decreased due to the side force, so-called hysteresis is generated in which the reciprocating position of the plunger 6 is different with respect to the same current value in the increasing / decreasing direction of the current value, and the hydraulic pressure is controlled with high accuracy. become unable. In the solenoid valve 1 of the present embodiment, this hysteresis is reduced to enable highly accurate hydraulic pressure control. Further, the non-magnetic member 30 having a predetermined thickness or the core stator 15 after being inserted can be easily managed in processing accuracy and assembly accuracy, and can be easily assembled in one direction in the same manner as the second core member 12. This is a good structural member that can be reliably implemented and maintains a small and uniform magnetic gap.

  The plunger 6 is a columnar member that is disposed in a plunger accommodating portion 34 formed in the cylindrical portion 32 of the nonmagnetic member 30 coaxially inserted in the first core member 11 so as to be reciprocally movable with a predetermined gap. It is. Although the inner peripheral surface of the cylindrical portion 32 of the nonmagnetic member 30 forms a smooth and accurate sliding surface, more preferably, in order to reduce the sliding resistance associated with the reciprocating movement of the plunger 6. In addition, the outer peripheral side surface of the plunger 6 may be coated with a resin material with high hardness by NiP plating or the like, and both end surfaces of the plunger 6 may be coated and used. In addition, the coating thickness of the plunger 6 increases the magnetic gap between the plunger 6 and the core stator 15 by the thickness, so that the attractive force is reduced. For this reason, the coating thickness of the plunger 6 is set as thin as possible. It is desirable that the nonmagnetic layer be made thin. In addition, a breathing hole 23 that communicates both spaces in the reciprocating direction of the plunger 6 is formed on the outer peripheral surface or inside of the plunger 6 so that the plunger 6 can be reciprocated quickly and smoothly.

  Further, the end surface on one side in the axial direction of the plunger 6 is perpendicular to the axial direction, forms a uniform gap facing the suction surface 22 formed on the other end surface of the second core member 12, and has a large suction force. A substantially uniform suction force is generated regardless of the displacement of the plunger 6. Although the coating thickness of the outer peripheral side surface for reducing the sliding resistance of the plunger 6 affects the eccentricity of the plunger 6 as described above, the degree of freedom in setting the thickness of the cylindrical portion 32 of the nonmagnetic member 30 Therefore, the eccentricity condition can be satisfied (established) even with a sufficiently thin coating thickness on the outer peripheral surface of the plunger 6.

  The solenoid 2, the core stator 15 and the like are surrounded and accommodated by the yoke 16. The caulking portion 16a on one side of the yoke 16 sequentially surrounds the outer periphery of the flange portion 17 of the first core member 11, the flange portion 18 of the second core member 12, and the flange portion 31 of the nonmagnetic member 30 from one side, By caulking and joining together with the flange portion 8a of the sleeve 8, the flange portions are brought into close contact with each other to maintain liquid tightness, and the valve body portion 4 and the drive portion 5 are connected.

[Operation of Example 1]
When the solenoid 2 is energized, a magnetic flux is generated by exciting the coil. The generated magnetic flux circulates through the magnetic paths of the core stator 15, the plunger 6 and the yoke 16. However, in the thin portion 19 of the first core member 11, the magnetic resistance is large, and the magnetic flux flows into the plunger 6 from the suction surface 22 of the second core member 12. At this time, a magnetic attractive force is generated in the gap between the attractive surface 22 and the one end surface 6a of the plunger 6. This magnetic attractive force acts on one side of the plunger 6, and the plunger 6 moves against the urging force of the spring 9, which is an urging means, and the spool 3 is interlocked with the plunger 6 via the shaft 13. Move to one side.

  By the movement of the spool 3, the spool 3 blocks or communicates with each port 7 of the sleeve 8, or changes the open / close ratio to control the inflow and outflow amount of hydraulic oil, that is, the flow rate or pressure.

  When the energization is turned off, the magnetic flux disappears, the magnetic attractive force acting on the plunger 6 disappears, and the spool 3 and the plunger 6 are initialized by the biasing force of the spring 9 which is the biasing means of the valve body 4. It is pushed back to the position and stops.

  From the above, the displacement of the plunger 6 is substantially determined mainly by the balance between the attractive force and the biasing force. Since the attractive force is proportional to the increase in the current value, the desired flow rate or pressure can be set easily and quickly by linear control of the current applied to the solenoid 2. At this time, the plunger 6 can be accurately moved in the plunger accommodating portion 34 having a smooth and uniform thickness without generating a large side force. As a result, it is possible to set the flow rate or pressure with high accuracy and stability.

[Effect of Example 1]
In this embodiment, a core stator that forms a magnetic circuit with a plunger is provided with a cylindrical portion that penetrates in the axial direction, and has a flange portion that is caulked and fixed to the other end of the sleeve on one side of the cylindrical portion. A suction surface that separates the core member and the first core member, has a cylindrical portion accommodated coaxially on one side of the cylindrical portion of the first core member, and sucks the plunger on the other side of the cylindrical portion A second core member having a flange portion that is caulked and fixed to the other end of the sleeve on one side, and is disposed between the first core member and the second core member, and has a predetermined thickness, It has a flange part for assembly on one side and a cylinder part accommodated in the cylinder part of the first core member on the other side, and has a predetermined gap on the other side of the cylinder part so that the plunger can be reciprocated freely. So that the suction surface of the cylindrical portion of the second core member faces the plunger. And a nonmagnetic member for location, housing the solenoid, sequentially surrounding each flange portion from one side to constitute a yoke for the caulking and the other side end portion of the sleeve, the solenoid valve comprising a.

  Thereby, since it can divide | segment into a 1st and 2nd core member and a 2nd core member can be coaxially inserted inside a 1st core member, the suction surface which is the other end of a 2nd core member is made into a 1st core member It is easy to place it facing one end of the plunger accommodated so as to be able to reciprocate, enhances the attractive force due to the magnetic force between the plunger and the core stator, and is substantially constant regardless of the displacement amount of the plunger Thus, stable control performance can be ensured, and a small and high performance solenoid valve can be realized.

  Further, a nonmagnetic member having a predetermined thickness is sandwiched between the inner periphery of the first core member and the outer periphery of the second core member, and the plunger is reciprocally accommodated on the inner periphery side of the nonmagnetic member. Therefore, the magnetic gap between the plunger and the core stator can be reduced to the thickness of the nonmagnetic member, and the attractive force of the plunger can be easily increased. Thereby, a small high-performance solenoid valve can be realized. Also, by reducing the thickness of the nonmagnetic member, the eccentricity of the plunger relative to the core stator can be suppressed to 20% or more and 60% or less without processing a large amount of resin coating or NiP plating as in the past. Therefore, the occurrence of hysteresis can be easily reduced. Thereby, while improving the linear control performance by increase / decrease in an electric current value, productivity improves and the small high performance solenoid valve which suppressed the cost increase is realizable.

  In addition, the first and second core members and the non-magnetic member can be processed separately by precision finishing of the inner peripheral surface of each cylindrical portion, taper finishing of the suction surface, surface treatment, etc. Assembling is a structure in which each flange is tightly fixed by caulking with a yoke that sequentially surrounds the flanges from one side, so that the machining efficiency of the unit is improved and machining accuracy and assembly accuracy management are simplified. As a result, one-way coaxial assembly is possible, productivity is improved, and high costs can be suppressed.

[Configuration of Example 2]
A second embodiment of the present invention is shown in FIG. FIG. 2 is an axial cross-sectional view of the solenoid valve according to the second embodiment. Components that are substantially the same as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  In Example 1, the core stator 15 constituting the magnetic circuit with the plunger 6 is divided into two parts, a first core member 11 and a second core member 12, and provided with flange portions 17 and 18 for assembly to each other. The cylindrical portion 20 of the two-core member 12 is coaxially inserted into the inner peripheral side of the cylindrical portion 10 of the first core member 11 and has a predetermined thickness between the first core member 11 and the second core member 12. The non-magnetic member 30 is sandwiched, and the plunger 6 is reciprocally accommodated in a plunger accommodating portion 34 provided on the other side of the cylindrical portion of the non-magnetic member 30, and is formed on the other end face of the cylindrical portion of the second core member 12. A predetermined magnetic gap is provided in the axial direction and the radial direction so as to face the attraction surface 22.

  However, the present invention is not limited to this, and in the present embodiment, a predetermined radial magnetic gap between the plunger 6 and the core stator 15 is simply determined by the thickness of the covering portion 6b made of a nonmagnetic material on the outer peripheral side surface of the plunger 6. This is a solenoid valve characterized in that the use of the nonmagnetic member 30 is stopped. This is the main difference between the present embodiment and the first embodiment, and other configurations are not greatly changed.

  As shown in FIG. 2, the core stator 15 is composed of two core members, includes a cylindrical portion 10 penetrating in the axial direction, and has a first core member 11 having a flange portion 17 for assembly on one side thereof. The first core member 11 is separate from the first core member 11 and is tightly fixed to the cylindrical portion 20 and the flange portion 17 accommodated coaxially on the inner circumference of one side of the cylindrical portion 10 of the first core member 11. The second core member 12 has a flange portion 18.

  The cylindrical portion 10 of the first core member 11 has a plunger accommodating portion 14 that accommodates the plunger 6 in a reciprocating manner with a predetermined gap and a large force that attracts the plunger 6 to one side in the reciprocating direction. In order to do so, a thin portion 19 is formed as a magnetoresistive portion that reduces the flow of magnetic flux to the plunger housing portion 14.

  Similarly, the second core member 12 includes a cylindrical portion 20 penetrating in the axial direction, and the outer peripheral side of the cylindrical portion 20 is a cylindrical shape that can be coaxially fitted to the inner periphery of the first core member 11. A bearing portion 21 that accommodates the shaft 13 in a reciprocating manner is formed on the circumferential side, and a suction surface 22 for generating a force that attracts the plunger 6 to the one side in the reciprocating direction is formed on the other side in the axial direction. Yes. When the second core member 12 is fitted coaxially with the first core member 11 to form the core stator 15, the length is such that the suction surface 22 reaches the set position of the thin portion 19 of the first core member 11. The other end of the cylindrical portion 20 is tapered and adjusted toward the axis so that the suction surface 22 is saturated with the magnetic flux when the maximum current value supplied to the solenoid 2 reaches approximately 50%. .

  The bearing portion 21 of the cylindrical portion 20 of the second core member 12 supports the shaft 13 so as to be slidable in the axial direction, and a finite gap is formed on the sliding surface between the bearing portion 21 and the shaft 13. The communication of air or hydraulic oil accompanying the displacement of the plunger 6 is ensured.

  The plunger 6 is a columnar member that is disposed so as to be reciprocally movable with a predetermined gap in a plunger accommodating portion 14 formed on the other side of the cylindrical portion 10 of the first core member 11. The outer peripheral surface of the plunger 6 that slides with the inner peripheral surface of the plunger accommodating portion 14 is formed with a resin material coating process for forming a predetermined radial magnetic gap and reducing sliding resistance, Alternatively, it is coated with NiP plating or the like to a uniform thickness. This coating thickness determines the magnetic gap based on the sum of the gap in which the plunger 6 is arranged in the plunger accommodating portion 14 with a predetermined gap, and since the degree of freedom in setting the coating thickness is high, It is easy to suppress the eccentricity with respect to the plunger accommodating portion 14 to 20% or more and 60% or less, and it is easy to configure an appropriate side gap.

  The outer peripheral surface of the plunger 6 may be covered with a SUS cup formed of a non-magnetic material such as stainless steel (SUS) without being limited to a resin material coating process or NiP plating. Alternatively, a thin plate formed of a nonmagnetic material in a quadrangular shape may be rolled into a cylindrical shape and fitted to the plunger 6 to be covered. The cylindrical thin plate may be merely fitted to the plunger 6 with an elastic force, or may be fixed to the plunger 6 by adhesion or welding.

  Further, the end surface on one side in the axial direction of the plunger 6 is perpendicular to the axial direction, forms a uniform gap facing the suction surface 22 formed on the other end surface of the second core member 12, and has a large suction force. A substantially uniform suction force is generated regardless of the displacement of the plunger 6. Note that a breathing hole 23 that communicates both spaces in the reciprocating direction of the plunger 6 is formed on the outer peripheral surface or inside of the plunger 6 so that the plunger 6 can be reciprocated quickly and smoothly.

  The solenoid 2, the core stator 15 and the like are surrounded and accommodated by the yoke 16. The caulking portion 16a on one side of the yoke 16 surrounds the outer periphery of the flange portion 17 of the first core member 11 and the flange portion 18 of the second core member 12 sequentially from one side, and is caulked and joined together with the flange portion 8a of the sleeve 8. By doing so, the valve body part 4 and the drive part 5 are connected to each other by keeping the flange parts in close contact with each other and maintaining liquid tightness.

[Effect of Example 2]
Unlike the solenoid valve in the first embodiment, the solenoid valve in the present embodiment inserts a nonmagnetic member into the core stator, that is, between the first core member and the second core member, and the inner circumference of the nonmagnetic member. Instead of setting the side gap suitable for the radial direction of the outer peripheral side surface of the plunger, a coating portion of a nonmagnetic material having a predetermined thickness is provided in the radial direction of the outer peripheral side surface of the plunger. Thus, a suitable side gap is set in the radial direction of the outer peripheral side surface of the plunger. As a result, the side gap can be reduced, the suction force can be easily increased, the eccentricity of the plunger can be suppressed, and the side force can be reduced, so that hysteresis with respect to increase / decrease in the current value can be reduced. Further, the main difference is only whether or not the nonmagnetic member is inserted, and other structures are not greatly changed, and the same operation and effect as in the first embodiment can be obtained. By stopping the operation, the number of parts to be assembled can be reduced, the number of assembling steps can be reduced, the productivity can be improved, and a small high-performance solenoid valve with reduced cost can be realized.

(Example 1) which is an axial sectional view of a solenoid valve. (Example 2) which is an axial sectional view of a solenoid valve. It is an axial sectional view of a solenoid valve (conventional example).

Explanation of symbols

1 Solenoid valve 2 Solenoid 3 Spool (valve)
4 Valve body part 5 Drive part 6 Plunger (mover)
6b Cover 7 port (oil passage)
8 Sleeve (housing)
8a, 17, 18, 31 Flange portion 9 Spring 10, 20, 32 Tube portion 11 First core member 12 Second core member 13 Shaft 14, 34 Plunger accommodating portion 15 Core stator (fixed core)
16 Yoke 16a Caulking portion 21 Bearing portion 22 Suction surface 30 Nonmagnetic member

Claims (2)

A mover,
In conjunction with the mover, reciprocates in the sleeve, and opens and closes the flow path of the sleeve to control the flow rate or pressure of the fluid; and
Urging means for urging the mover to one side in the reciprocating direction;
A solenoid that generates a magnetic force to attract the mover to the other side in the reciprocating direction;
A fixed core that forms a magnetic circuit with the mover, and includes a cylindrical portion that penetrates in an axial direction, and a flange portion that is caulked and fixed to the other end of the sleeve on one side of the cylindrical portion. A core member;
The first core member is separate from the first core member and has a cylindrical portion that is coaxially accommodated on one side of the cylindrical portion, and the movable element is sucked to the other side of the cylindrical portion. A second core member having a suction surface and having a flange portion that is caulked and fixed to the other end of the sleeve on one side;
A flange portion is disposed between the first core member and the second core member, has a predetermined thickness, has a flange portion for assembly on one side, and the tube of the first core member on the other side. A cylindrical portion that is accommodated in the portion, and has a predetermined gap on the other side of the cylindrical portion to accommodate the movable element so as to be able to reciprocate. One side is the suction of the cylindrical portion of the second core member A nonmagnetic member having a surface disposed so as to face the mover;
A yoke that accommodates the solenoid, sequentially surrounds the flanges from one side, and is caulked with the other side end of the sleeve;
A solenoid valve consisting of A mover having a nonmagnetic material coating on the reciprocating sliding surface;
A valve body that reciprocates in conjunction with the mover, is accommodated in a sleeve, and controls the flow rate or pressure of the fluid by opening and closing the flow path of the sleeve;
Urging means for urging the mover to the other side in the reciprocating direction;
A solenoid that generates a magnetic force to attract the mover to one side in the reciprocating direction;
A fixed core that forms a magnetic circuit with the mover, the movable part being interposed between a cylindrical part that covers an outer peripheral side surface of the movable element, a flange part that is caulked and fixed to the other end of the sleeve, and the cylindrical part A first core member having a predetermined gap in the reciprocating direction of the child;
A second surface having a suction surface for sucking the movable element on the other side in the reciprocating direction, having a flange portion coaxially accommodated in the cylindrical portion of the first core member and caulked and fixed to the other end of the sleeve. A core member;
The movable element is reciprocally accommodated on the other side of the cylindrical portion of the first core member so as to face the suction surface on the other side of the cylindrical portion of the second core member,
A yoke that accommodates the solenoid, sequentially surrounds the flanges from one side, and is caulked with the other side end of the sleeve;
A solenoid valve consisting of

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