JP2012167766A - Electromagnetic linear valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnetic linear valve, in which self-excited vibration can be suppressed while the performance of proper differential pressure control is secured.SOLUTION: The electromagnetic linear valve 10 includes: (a) a housing including tube parts 28, 82, and a partitioning part that divides the interior thereof into a first liquid chamber and a second liquid chamber and is formed with a through hole connecting the chambers with each other; and (b) a plunger 22 movable in an axis line direction and disposed in the first liquid chamber so that a tip part thereof can be seated on an opening of the through hole. The electromagnetic linear valve includes two non-magnetic liners 78, 80 interposed between an inner periphery of the tube part and an outer periphery of the plunger, fixed to one of the two peripheries while spaced apart from each other in an axis line direction and coming into slide contact with the other of the two peripheries, wherein the inner periphery of the tube part and the outer periphery of the plunger are configured to face each other without contacting with each other between the two liners. The configuration prevents magnetic close contact and generates large electromotive force based on electromagnetic induction to suppress the self-excited vibration of the plunger by the electromotive force.

Description

  The present invention relates to an electromagnetic linear valve that includes a plunger and a housing in which the plunger is movable in the axial direction thereof, and opens and closes the valve by moving the plunger.

  The electromagnetic linear valve includes: (a) a cylindrical housing cylinder, a core that closes one end of the housing cylinder, and the interior of the housing cylinder divided into a first liquid chamber and a second liquid chamber. And a housing having a partition portion through which the first liquid chamber and the second liquid chamber communicate with each other, and (b) one end portion is a core portion and the other end portion is a through hole. There is an electromagnetic linear valve provided with a plunger that is disposed in the first liquid chamber so as to be movable in the axial direction in a state of being opposed to the opening, and can be seated on the opening at the other end. An electromagnetic linear valve equipped with such a plunger and housing prohibits the flow of hydraulic fluid from the hydraulic fluid passage on the high pressure side to the hydraulic fluid passage on the low pressure side when the valve element is seated on the valve seat. In the state where the valve body is away from the valve seat, the flow of the hydraulic fluid from the high-pressure side hydraulic fluid passage to the low-pressure side hydraulic fluid passage is permitted. Furthermore, the elastic body that biases the plunger in one of the direction in which the valve body approaches the valve seat and the direction in which the valve body moves away from the valve seat, and the plunger moves in a direction opposite to the direction in which the elastic body biases the plunger. And a coil that forms a magnetic field for controlling the hydraulic pressure of the hydraulic fluid in the hydraulic fluid passage on the high-pressure side (hereinafter referred to as “high-pressure hydraulic fluid pressure”) by controlling the amount of current supplied to the coil. The differential pressure between the hydraulic pressure of the hydraulic fluid in the low-pressure side hydraulic fluid passage (hereinafter sometimes referred to as “low-pressure side hydraulic fluid pressure”) can be changed in a controllable manner. The following patent document describes an example of an electromagnetic linear valve having a structure capable of controlling a differential pressure between a high-pressure side hydraulic fluid pressure and a low-pressure side hydraulic fluid pressure.

JP 2008-39157 A

  The electromagnetic linear valve having the above structure is configured to control the amount of current applied to the coil and control the force acting on the plunger when controlling the differential pressure between the high-pressure side hydraulic fluid pressure and the low-pressure side hydraulic fluid pressure. ing. For this reason, for example, if a large frictional force is generated between the outer peripheral surface of the plunger and the inner peripheral surface of the housing, there is a possibility that the differential pressure control between the high-pressure side hydraulic fluid pressure and the low-pressure side hydraulic fluid pressure cannot be appropriately executed. . On the other hand, in the electromagnetic linear valve having the above structure, since the plunger is supported by an elastic body in the housing, there is a problem of the self-excited vibration of the plunger. It is known that the frictional force generated between the surface and the inner peripheral surface of the housing is effective. For this reason, although it is desirable to reduce a frictional force, there exists a possibility that it will become difficult to suppress the self-excited vibration of a plunger only by reducing a frictional force. This invention is made | formed in view of such a situation, While providing execution of appropriate differential pressure control, providing an electromagnetic linear valve which can suppress the self-excited vibration of a plunger is provided. Let it be an issue.

  In order to solve the above problems, the electromagnetic linear valve of the present invention is interposed between the inner peripheral surface of the housing cylindrical portion and the outer peripheral surface of the plunger, and is axially disposed on one surface of the two surfaces. 2, two non-magnetic liners that are fixed in a state of being separated from each other and that are in sliding contact with the other surface that is the other of the inner peripheral surface of the housing cylindrical portion and the outer peripheral surface of the plunger, and between the two liners, The other surface is configured to face each other without contact.

  When the plunger moves while the magnetic flux is flowing in the plunger, an electromotive force based on electromagnetic induction is generated. This electromotive force increases as the density of the magnetic flux flowing through the plunger increases, and is generated in a direction that hinders the movement of the plunger. The electromotive force that relies on electromagnetic induction changes according to the moving speed of the plunger, and increases as the moving speed increases, but no electromotive force is generated when the plunger is stopped. For this reason, an electromotive force that increases as the moving speed of the plunger increases is suitable for attenuating the self-excited vibration of the plunger. In the electromagnetic linear valve of the present invention, the inner peripheral surface of the housing cylinder portion and the outer peripheral surface of the plunger face each other between the two nonmagnetic liners without contact. For this reason, the magnetic flux flowing between the plunger and the housing cylinder hardly flows to the two non-magnetic liners, concentrates between the two liners, and the density of the magnetic flux flowing between the two liners. Becomes higher. Thereby, a large electromotive force can be generated, and the self-excited vibration of the plunger can be effectively suppressed. In the electromagnetic linear valve of the present invention, two non-magnetic liners are interposed between the outer peripheral surface of the plunger and the inner peripheral surface of the housing cylindrical portion, so that the magnetic contact between the plunger and the housing cylindrical portion is achieved. Can be prevented, and the frictional force can be reduced. Therefore, according to the electromagnetic linear valve of the present invention, it is possible to ensure execution of appropriate differential pressure control and to suppress the self-excited vibration of the plunger.

Aspects of the Invention

  In the following, some aspects of the invention that can be claimed in the present application (hereinafter sometimes referred to as “claimable invention”) will be exemplified and described. As with the claims, each aspect is divided into sections, each section is numbered, and is described in a form that cites the numbers of other sections as necessary. This is merely for the purpose of facilitating the understanding of the claimable inventions, and is not intended to limit the combinations of the constituent elements constituting those inventions to those described in the following sections. In other words, the claimable invention should be construed in consideration of the description accompanying each section, the description of the embodiments, etc., and as long as the interpretation is followed, another aspect is added to the form of each section. In addition, an aspect in which constituent elements are deleted from the aspect of each item can be an aspect of the claimable invention.

  In each of the following items, item (1) corresponds to claim 1, and the technical features described in item (2) are added to item 1 and item 2 (3). ) And (4) are added with the technical features described in claim 3, and claims 2 or 3 are added with the technical features described in (5) in claim 4. Any one of claims 1 to 3 is provided with the technical feature described in (6) in addition to claim 5 and in any one of claims 1 to 5 in (7). The addition of the technical feature described in the item corresponds to claim 6, and the addition of the technical feature described in the item (8) to claim 6 corresponds to the claim 7.

(1) (a) a cylindrical housing cylinder part, (b) a core part closing one end of the cylindrical housing part, and (c) a first part located inside the housing cylindrical part on the core part side. A partition section that is partitioned into a liquid chamber and a second liquid chamber located on the opposite side of the core section, and a through-hole that penetrates the first liquid chamber and the second liquid chamber is formed so as to communicate with each other. And (d) a housing having an outflow port communicating with the first liquid chamber, and (e) an inflow port communicating with the second liquid chamber;
A plunger, one end of which is disposed in the first liquid chamber so as to be movable in the axial direction with the other end facing the opening of the through hole, and a plunger which can be seated in the opening at the other end; ,
An elastic body that biases the plunger in one of a direction in which the other end of the plunger approaches the opening of the through hole and a direction in which the other end of the plunger separates from the opening;
An electromagnetic linear valve comprising: a coil provided around the housing and forming a magnetic field for moving the plunger in a direction opposite to a direction in which the elastic body biases the plunger;
The electromagnetic linear valve
Interposed between the inner peripheral surface of the housing cylindrical portion and the outer peripheral surface of the plunger, and fixed to one of the two surfaces in a state of being separated from each other in the axial direction. An electromagnetic system comprising two non-magnetic liners that are in sliding contact with the other surface that is the other of the peripheral surface and the outer peripheral surface of the plunger, and the one surface and the other surface facing each other without contact between the two liners Linear valve.

  In the electromagnetic linear valve, the outer diameter of the plunger is slightly smaller than the inner diameter of the housing tube, and smooth movement of the plunger within the housing is ensured. However, the plunger normally moves while being in sliding contact with the inner peripheral surface of the housing cylindrical portion, and a frictional force is generated between the outer peripheral surface of the plunger and the inner peripheral surface of the housing cylindrical portion. However, the electromagnetic linear valve has a structure that controls the power applied to the plunger by controlling the energization amount to the coil during the differential pressure control between the high-pressure side hydraulic fluid pressure and the low-pressure side hydraulic fluid pressure. When such a frictional force becomes large, there is a possibility that the differential pressure control between the high-pressure side hydraulic fluid pressure and the low-pressure side hydraulic fluid pressure cannot be properly executed. In particular, when the ferromagnetic plunger comes into contact with the ferromagnetic member of the housing, magnetic adhesion occurs, and the frictional force is considerably increased. On the other hand, in the electromagnetic linear valve, since the plunger is supported by the elastic body in the housing, there is a problem of the self-excited vibration of the plunger, and the frictional force is effective to suppress the self-excited vibration. It has been known. For this reason, it is desirable to reduce the frictional force, but it is difficult to suppress the self-excited vibration of the plunger only by reducing the frictional force.

  In view of the above, in the electromagnetic linear valve described in this section, two non-magnetic liners are interposed between the inner peripheral surface of the housing cylindrical portion and the outer peripheral surface of the plunger, and the two liners Is fixed to one surface, which is one of the inner peripheral surface of the housing cylindrical portion and the outer peripheral surface of the plunger, in a state of being separated from each other in the axial direction, and is the other of the inner peripheral surface of the housing cylindrical portion and the outer peripheral surface of the plunger Touching the other side. And it is comprised so that one surface and the other surface may face each other between these two liners, without contacting. With such a configuration, it is possible to prevent magnetic contact between the plunger and the housing cylindrical portion and to increase the density of the magnetic flux flowing between the two liners. More specifically, since the two non-magnetic liners are interposed between the outer peripheral surface of the plunger and the inner peripheral surface of the housing cylinder portion, the plunger and the housing cylinder portion are not in contact with each other, and magnetic adhesion is prevented. . In addition, the inner peripheral surface of the housing cylinder and the outer peripheral surface of the plunger face each other between the two nonmagnetic liners without contact. For this reason, the magnetic flux flowing between the plunger and the housing cylinder hardly flows to the two non-magnetic liners, concentrates between the two liners, and the density of the magnetic flux flowing between the two liners. Becomes higher.

  The density of the magnetic flux flowing in the plunger will be described in detail later, but it is greatly related to the electromotive force that relies on the electromagnetic induction that occurs when the plunger moves. If the density of the magnetic flux that flows in the plunger increases, the electromotive force also increases. growing. The electromotive force is generated in a direction that hinders the movement of the plunger, and increases as the movement speed of the plunger increases. That is, no electromotive force is generated when the plunger is stopped. From this, according to the electromotive force based on electromagnetic induction, it becomes possible to effectively attenuate the self-excited vibration of the plunger. In the electromagnetic linear valve described in this section, as described above, the density of the magnetic flux flowing between the two liners is increased, and the self-excited vibration of the plunger can be effectively suppressed. Further, in the electromagnetic linear valve described in this section, it is possible to reduce the frictional force that hinders the differential pressure control by preventing the magnetic contact between the plunger and the housing cylinder. Therefore, according to the electromagnetic linear valve described in this section, it is possible to ensure execution of appropriate differential pressure control and to suppress the self-excited vibration of the plunger.

  The “liner” described in this section may be any one that is interposed between the inner peripheral surface of the housing cylindrical portion and the outer peripheral surface of the plunger and prevents contact between the housing cylindrical portion and the plunger. Like a cylindrical member, it may be constituted by one member, and by combining a plurality of plate-like members that are curved along the inner peripheral surface of the housing cylindrical portion and the outer peripheral surface of the plunger. It may be configured. In addition, the “one side” and the “other side” described in this section need only face each other without contact between the two liners, but the distance between the two sides, that is, the It is desirable that the clearance between the two surfaces be the smallest between the two liners in order to effectively increase the magnetic flux density between the two liners.

  (2) The electromagnetic linear valve according to (1), wherein each of the two liners has a cylindrical shape.

  According to the electromagnetic linear valve described in this section, the liner shape can be simplified.

  (3) In a state where the two liners are in sliding contact with the other surface, a separation distance between the one surface and the other surface facing each other between the two liners is greater than a thickness in a radial direction of the two liners. The electromagnetic linear valve according to Item (2).

  (4) The electromagnetic linear valve according to (3), wherein the separation distance is 1/600 or more and 1/10 or less of the thickness of the two liners.

  In the electromagnetic linear valve described in the above two items, it is possible to effectively increase the density of the magnetic flux flowing between the plunger and the housing cylindrical portion between the two liners. In the electromagnetic linear valve described in the above two items, one of the one surface and the other surface may protrude over the entire circumference toward the other in order to make the “separation distance” smaller than the thickness of the liner. The protruding portion, that is, the cylindrical portion may be a single ferromagnetic member, and the inner peripheral surface or the outer peripheral surface of the cylindrical ferromagnetic member may constitute a part of one surface. The “separation distance” described in the latter section is desirably 1/100 or more and 1/20 or less of the thickness of the two liners, and more specifically 1/60 or more and 1 / 20 or less is desirable.

(5) One of the housing tube portion having the one surface and the plunger is
The main body and a cylindrical member fixedly fitted to the main body are formed into a stepped shape, and the surface of the cylindrical member opposite to the surface in contact with the main body is the one surface. The electromagnetic linear valve according to any one of (2) to (4), wherein the electromagnetic linear valve functions as a part and is fixedly fitted to the main body so that the two liners sandwich the cylindrical member .

  In the electromagnetic linear valve described in this section, at least the main body and the cylindrical member are integrated to form a plunger or a housing cylindrical portion. That is, for example, a cylindrical member or a columnar member is adopted as the main body, and the cylindrical member is fitted to the member, so that these two members are integrated, or the outer peripheral surface or the outer peripheral surface. The surface functions as one surface. The “cylindrical member” described in this section is desirably a thickness that does not exceed the thickness of the liner in order to avoid contact with the other surface, and when the thickness is the same as the thickness of the liner, As will be described in detail later, it is necessary to form a concave portion in the circumferential direction on the other surface.

(6) The one surface is
The electromagnetic linear valve according to any one of the items (1) to (4), which projects between the two liners over the entire circumference toward the other surface.

  In the electromagnetic linear valve described in this section, a convex portion protruding in the radial direction is formed on one surface over the entire circumference, and two liners are disposed so as to sandwich the convex portion. In order to avoid contact with the other side, it is desirable that the protruding amount of the convex part not exceed the thickness of the liner, and when the amount corresponds to the thickness of the liner, the other side In addition, as will be described in detail later, it is necessary to form a recessed portion in the circumferential direction.

(7) The other side is
The electromagnetic linear valve according to any one of items (1) to (6), which is recessed over the entire circumference at a position facing the portion between the two liners on the one surface.

  In the electromagnetic linear valve described in this section, a concave portion that is recessed over the entire circumference is formed on the other surface, and the concave portion faces a portion between the two liners on one surface. According to such a configuration, for example, even when the protruding amount of the convex portion or the thickness of the cylindrical member is the same as the thickness of the liner, the contact between the one surface and the other surface is maintained. It is possible to avoid it reliably.

(8) The electromagnetic linear valve
The electromagnetic linear valve according to (7), comprising a conductive nonmagnetic member that is disposed in a portion that is recessed over the entire circumference of the other surface and is formed of a nonmagnetic and highly conductive material.

  When an electromotive force is generated based on electromagnetic induction that can effectively suppress the self-excited vibration of the plunger, a so-called eddy current flows in a vortex in a highly conductive portion. In the electromagnetic linear valve described in this section, since the conductive nonmagnetic member is disposed at a location where the magnetic flux flows densely, an eddy current can be generated in the member and a larger electromotive force can be generated. It becomes possible. Therefore, according to the electromagnetic linear valve described in this section, it is possible to more effectively suppress the self-excited vibration of the plunger. The “conductive nonmagnetic member” described in this section may be formed of a material that is nonmagnetic and highly conductive. Examples of the material include various materials such as gold, copper, and aluminum. Can be adopted.

(9) The one surface is an inner peripheral surface of the housing tube portion,
The electromagnetic linear valve according to any one of items (1) to (8), wherein the other surface is an outer peripheral surface of the plunger.

  In the aspect described in this section, two liners are fixed to the inner peripheral surface of the housing cylindrical portion, and a plunger is inserted into the two liners and the housing cylindrical portion. For this reason, for example, as described above, when the concave portion is formed over the entire circumference on the other surface, the concave portion is formed over the entire circumference on the outer peripheral surface of the plunger. On the other hand, in a mode opposite to the mode described in this section, when a recess is formed on the other surface over the entire periphery, it is necessary to form a recess over the entire periphery on the inner peripheral surface of the housing cylindrical portion. It is difficult to form such a recess on the inner peripheral surface of the cylindrical member, but it can be easily formed if the outer peripheral surface of the cylindrical member. Therefore, according to the aspect described in this section, the manufacturing process of the electromagnetic linear valve can be simplified.

  (10) In any one of items (1) to (9), the elastic body biases the plunger in a direction in which the other end of the plunger approaches the opening of the through hole. The electromagnetic linear valve described.

  The electromagnetic linear valve described in this section is limited to a normally closed electromagnetic linear valve. It is known that the frequency of occurrence of self-excited vibration of the plunger is generally higher in the normally closed electromagnetic linear valve than in the normally open electromagnetic linear valve. Therefore, in the electromagnetic linear valve described in this section, the effect of suppressing the self-excited vibration of the plunger is sufficiently utilized.

It is a schematic sectional drawing which shows the electromagnetic linear valve which is an Example of claimable invention. It is an enlarged view of the electromagnetic linear valve of FIG. It is a general | schematic expanded sectional view which shows the electromagnetic linear valve which is the 1st modification of claimable invention. It is a schematic sectional drawing which shows the electromagnetic linear valve which is the 2nd modification of claimable invention. It is a schematic sectional drawing which shows the electromagnetic linear valve which is the 3rd modification of claimable invention.

  Hereinafter, embodiments and modifications of the claimable invention will be described in detail with reference to the drawings. In addition to the embodiments described below, the present invention can be claimed in various aspects including various modifications and improvements based on the knowledge of those skilled in the art, including the aspects described in the above [Aspect of the Invention] section. Can be implemented.

<Configuration of electromagnetic linear valve>
FIG. 1 shows an electromagnetic linear valve 10 according to an embodiment of the present invention. The electromagnetic linear valve 10 is connected to a high-pressure side hydraulic fluid path 12 and a low-pressure side hydraulic fluid path 14. Normally, the valve body closes the valve seat, so that the low-pressure side hydraulic fluid path 12 has a low pressure. The flow of hydraulic fluid to the hydraulic fluid passage 14 on the side is prohibited. On the other hand, when a gap is generated between the valve body and the valve seat, the flow of hydraulic fluid from the hydraulic fluid passage 12 on the high pressure side to the hydraulic fluid passage 14 on the low pressure side is allowed and the flow of hydraulic fluid is allowed. The differential pressure between the hydraulic fluid pressure in the high-pressure side hydraulic fluid passage 12 and the hydraulic fluid pressure in the low-pressure hydraulic fluid passage 14 can be changed in a controllable manner.

  As shown in FIG. 1, the electromagnetic linear valve 10 includes a hollow housing 20, a plunger 22 provided in the housing 20 so as to be movable in the axial direction thereof, and a cylinder provided on the outer periphery of the housing 20. The coil 24 is provided. The housing 20 includes a core 26 as a columnar core provided at the upper end, a generally cylindrical wall member 28 constituting a wall surface, and a covered cylindrical valve fitted into the lower end of the wall member 28. Member 30. The core 26 and the wall member 28 are formed of a ferromagnetic material, and the core 26 and the wall member 28 are connected in a separated state via a cylindrical sleeve 32 formed of a nonmagnetic material. ing.

  The wall member 28 has a stepped interior, and is positioned between the upper end 50 located at the upper end, the lower end 52 located at the lower end, and the upper end 50 and the lower end 52. At the same time, it can be divided into an intermediate portion 54 having an inner diameter smaller than the inner diameters of the upper end portion 50 and the lower end portion 52. A valve member 30 as a partitioning portion is fixedly fitted to the lower end portion 52 of the wall member 28, and the inside of the housing 20 is partitioned into a first liquid chamber 58 and a second liquid chamber 60 by the valve member 30. Has been. The second liquid chamber 60 is opened at the lower end surface of the housing 20, and the opening functions as an inflow port so that the high-pressure side hydraulic fluid path 12 is connected to the second liquid chamber 60. The valve member 30 is formed with a through hole 62 penetrating in the axial direction. An opening 64 above the through hole 62 is formed in a tapered shape, and the opening 64 functions as a valve seat.

  The plunger 22 is made of a ferromagnetic material, and is disposed in the first liquid chamber 58 defined by the core 26, the wall member 28, and the valve member 30 so as to be movable in the axial direction. The plunger 22 is positioned below the first cylindrical portion 70 having the largest outer diameter, the second cylindrical portion 72 having an outer diameter smaller than the outer diameter of the first cylindrical portion 70, and the first cylindrical portion 70. The second cylindrical portion 72 is positioned below the second cylindrical portion 72 and has a third cylindrical portion 74 having an outer diameter smaller than that of the second cylindrical portion 72. The third cylindrical portion 74 is positioned below the third cylindrical portion 74. It is comprised by the rod part 76 of the outer diameter smaller than an outer diameter, and is made into the step shape.

  The first cylindrical portion 70 of the plunger 22 is provided so as to face the core 26 and is inserted into the upper end portion 50 of the wall member 28, and the second cylindrical portion 72 and the third cylindrical portion 74 are connected to the intermediate portion 54. Has been inserted. Between the third columnar portion 74 of the plunger 22 and the intermediate portion 54 of the wall member 28, three cylindrical members are interposed side by side in the axial direction. More specifically, non-magnetic cylindrical members 78 and 80 as two cylindrical liners formed of a non-magnetic material are fixed to the inner peripheral surface of the intermediate portion 54 of the wall member 28 in a state of being separated in the axial direction. A cylindrical ferromagnetic cylindrical member 82 formed of a ferromagnetic material is fixedly fitted between the two nonmagnetic cylindrical members 78 and 80. The two nonmagnetic cylindrical members 78 and 80 and the ferromagnetic cylindrical member 82 have the same thickness in the radial direction, and the inside of the two nonmagnetic cylindrical members 78 and 80 and the ferromagnetic cylindrical member 82 is the same. The circumferential surface is flush. The third cylindrical portion 74 of the plunger 22 is inserted into the three cylindrical members 78, 80, and 82, and the three cylindrical members 78, 80, and 82 are flush with each other. The inner diameter of the peripheral surface is slightly larger than the outer diameter of the third cylindrical portion 74. The inner diameter of the upper end portion 50 of the wall member 28 is slightly larger than the outer diameter of the first cylindrical portion 70 of the plunger 22, and the inner diameter of the intermediate portion 54 is slightly larger than the outer diameter of the second cylindrical portion 72. The plunger 22 can be moved smoothly in the axial direction within the housing 20.

  Further, the clearance between the inner peripheral surface of the upper end portion 50 of the wall member 28 and the outer peripheral surface of the first columnar portion 70 of the plunger 22, and the inner peripheral surface of the intermediate portion 54 of the wall member 28 and the second column of the plunger 22. The clearance between the outer peripheral surface of the portion 72 and the outer peripheral surface of the third cylindrical portion 74 of the plunger is the clearance between the inner peripheral surface that is flush with the three cylindrical members 78, 80, and 82. It has been enlarged. On the outer peripheral surface as the other surface of the third cylindrical portion 74 of the plunger 22, as shown in FIG. 2, a circumferential recess 84 that is recessed over the entire circumference is formed at a position facing the ferromagnetic cylindrical member 82. Yes. Therefore, when the axis of the plunger 22 and the axis of the housing 20 are misaligned, the plunger 22 comes into contact only with the two nonmagnetic cylindrical members 78 and 80. That is, even if the axis of the plunger 22 and the axis of the housing 20 are misaligned, the plunger 22 does not come into contact with the housing cylindrical portion formed by the wall member 28 and the ferromagnetic cylindrical member 82.

  Incidentally, FIG. 2 shows a state in which the axis of the plunger 22 and the axis of the housing 20 are deviated. From this figure, the plunger 22 contacts the two nonmagnetic cylindrical members 78 and 80, but as a cylindrical member. It can be seen that no contact is made with the ferromagnetic cylindrical member 82. In addition, the thickness α in the radial direction of the three cylindrical members 78, 80, 82 is 250 μm, and the depth β in the radial direction of the circumferential recess 84 is 7 μm. That is, the depth β in the radial direction of the circumferential recess 84, in other words, the shortest distance between the bottom surface of the circumferential recess 84 and the inner peripheral surface of the ferromagnetic cylindrical member 82 is the three cylindrical members 78, In FIG. 2, the depth β of the circumferential recess 84 is set so as to clarify that the plunger 22 and the ferromagnetic cylindrical member 82 do not contact each other. It is shown deeper than the actual one.

  Further, as shown in FIG. 2, a pair of grooves 86, 88 are formed on the outer peripheral surfaces of the two nonmagnetic cylindrical members 78, 80 over the entire circumference at both ends in the axial direction. The nonmagnetic cylindrical members 78 and 80 have a symmetrical structure in the axial direction. On the other hand, a pair of grooves 90 are formed on the outer peripheral surface of the ferromagnetic cylindrical member 82 over the entire circumference at both ends in the axial direction, and the ferromagnetic cylindrical member 82 also has a symmetrical structure in the axial direction. Has been. The grooves 86, 88, 90 formed in the cylindrical members 78, 80, 82 are formed in the intermediate portion 54 of the wall member 28 as a main body when the electromagnetic linear valve 10 is manufactured. It is formed in order to contain a press-fitting burr that may occur when press-fitting. For this reason, when the electromagnetic linear valve 10 is manufactured, it is possible to press-fit into the intermediate portion 54 of the wall member 28 from any one of both ends of each cylindrical member 78, 80, 82. 10 manufacturing processes can be simplified. Further, the two non-magnetic cylindrical members 78 and 80 have the same size, that is, one type of member, and the types of parts of the electromagnetic linear valve 10 are reduced.

  The lower end of the rod portion 76 of the plunger 22 is hemispherical and faces the opening 64 of the through hole 62 formed in the valve member 30. The lower end of the rod portion 76 is seated in the opening 64 and functions as a valve body. The lower end of the rod portion 76 that functions as the valve body is seated in the opening 64 that functions as a valve seat, so that the through hole 62 can be closed. In addition, the valve chamber 92 defined by the first liquid chamber 58 positioned around the rod portion 76, more specifically, the valve member 30, the lower end portion 52 of the wall member 28, and the nonmagnetic cylindrical member 80, is formed on the wall member 28. An opening is formed in the outer wall surface of the lower end 52, and the opening functions as an outflow port, whereby the low-pressure side hydraulic fluid passage 14 is connected to the valve chamber 92, that is, the first fluid chamber 58.

  Further, a concave portion 102 is formed on the lower end surface of the core 26 of the housing 20 so as to face the convex portion 100 formed on the upper end surface of the plunger 22, and the concave portion 102 extends in the axial direction of the plunger 22. Along with the movement, the convex portion 100 of the plunger 22 enters. A bottomed hole 104 is formed in the upper end surface of the convex portion 100 of the plunger 22, and a compression coil spring 106 is inserted into the bottomed hole 104. The upper end portion of the compression coil spring 106 protrudes from the upper end surface of the plunger 22, and the compression coil spring 106 is disposed in a compressed state by the bottom surface of the recess 102 formed in the core 26 and the bottom surface of the bottomed hole 104. Has been. For this reason, the plunger 22 is biased in a direction away from the core 26 by the elastic force of the compression coil spring 106 as an elastic body. That is, the tip of the rod portion 76 of the plunger 22 is biased in a direction approaching the opening 64 (hereinafter sometimes referred to as “approach direction”). A rod-shaped stopper 108 is inserted into the bottomed hole 104 so as to be surrounded by the compression coil spring 106, and the amount of upward movement of the plunger 22 is limited by the stopper 108.

  The coil 24 is held at the outer peripheral portion of the housing 20 by a resin holding member 110, and is covered with a coil case 112 formed of a ferromagnetic material together with the holding member 110. The coil case 112 is fixed to the core 26 at the upper end and is fixed to the wall member 28 at the lower end. For this reason, a magnetic path is formed in the coil case 112, the core 26, the plunger 22, and the wall member 28 as the magnetic field is formed by the coil 24.

<Operation of electromagnetic linear valve>
With the above-described structure, the electromagnetic linear valve 10 prohibits the flow of hydraulic fluid from the high-pressure side hydraulic fluid passage 12 to the low-pressure side hydraulic fluid passage 14 when no current is supplied to the coil 24. By supplying a current to the coil 24, the flow of hydraulic fluid from the hydraulic fluid passage 12 on the high pressure side to the hydraulic fluid passage 14 on the low pressure side is allowed and the operation on the high pressure side when the flow of hydraulic fluid is allowed. The differential pressure between the hydraulic pressure of the hydraulic fluid in the liquid passage 12 and the hydraulic pressure of the hydraulic fluid in the low-pressure side hydraulic fluid passage 14 is controllably changed.

More specifically, when no current is supplied to the coil 24, the opening of the through hole 62 in which the tip of the rod portion 76 of the plunger 22 is connected to the hydraulic fluid path 12 on the high pressure side by the elastic force of the compression coil spring 106. By closing 64, the electromagnetic linear valve 10 prohibits the flow of hydraulic fluid from the high-pressure side hydraulic fluid passage 12 to the low-pressure side hydraulic fluid passage 14. At this time, at the tip of the rod portion 76, the hydraulic pressure of the hydraulic fluid in the high-pressure side hydraulic fluid passage 12 (hereinafter sometimes referred to as “high-pressure hydraulic fluid pressure”) and the low-pressure side hydraulic fluid passage 14. A force F ₁ based on the difference from the hydraulic pressure of the hydraulic fluid (hereinafter sometimes referred to as “low-pressure side hydraulic fluid pressure”) is acting. The force F ₁ based on the pressure difference and the elastic force F ₂ of the compression coil spring 106 act in opposite directions, but the elastic force F ₂ is made somewhat larger than the force F ₁ based on the pressure difference. The electromagnetic linear valve 10 does not open when no current is supplied to the coil 24.

On the other hand, when a current is supplied to the coil 24, the magnetic flux passes through the coil case 112, the core 26, the plunger 22, and the wall member 28 as the magnetic field is formed. Then, a magnetic force is generated to move the plunger 22 in a direction in which the tip of the rod portion 76 is separated from the opening 64 of the through hole 62 (hereinafter sometimes referred to as “separation direction”). When a current is supplied to the coil 24 to form a magnetic field, the plunger 22 has a sum of a force F ₁ based on the pressure difference and a force F ₃ that biases the plunger 22 upward by the magnetic force, The elastic force F ₂ of the compression coil spring 106 acts in the opposite direction. At this time, while the sum of the force F ₁ based on the pressure difference and the biasing force F ₃ due to the magnetic force is larger than the elastic force F _2, the opening 64 closed by the tip of the rod portion 76 opens, and the high pressure side The hydraulic fluid flows from the hydraulic fluid passage 12 to the hydraulic fluid passage 14 on the low pressure side.

The working fluid of high pressure that flows into the hydraulic fluid passage 14 of the low-pressure side, an increase in the low-pressure side hydraulic fluid pressure, a force F ₁ based on the pressure difference is reduced. If the force F ₁ based on the pressure difference decreases and the sum of the force F ₁ based on the pressure difference and the biasing force F ₃ based on the magnetic force becomes smaller than the elastic force F ₂ , the electromagnetic linear valve 10 is closed. The flow of the hydraulic fluid from the high-pressure side hydraulic fluid passage 12 to the low-pressure side hydraulic fluid passage 14 is blocked. Therefore, the low-pressure side hydraulic fluid pressure is maintained at the low-pressure side hydraulic fluid pressure at the time when the sum of the force F ₁ based on the pressure difference and the biasing force F ₃ based on the magnetic force becomes smaller than the elastic force F ₂ . That is, by controlling the energization amount to the coil 24, it becomes possible to control the pressure difference between the low-pressure side hydraulic fluid pressure and the high-pressure side hydraulic fluid pressure up to the target hydraulic fluid pressure. It is possible to increase.

As described above, in the electromagnetic linear valve 10, the magnetic force F ₃ that moves the plunger 22, that is, the amount of magnetic flux that passes through the coil case 112, the core 26, the plunger 22, and the wall member 28 is controlled. Thus, the differential pressure between the low-pressure side hydraulic fluid pressure and the high-pressure side hydraulic fluid pressure is controlled. At the time of this differential pressure control, a magnetic flux flows between the plunger 22 and the wall member 28, and an attractive force is generated between the plunger 22 and the wall member 28. As described above, the plunger 22 Only the two nonmagnetic cylindrical members 78 and 80 are in sliding contact. That is, the plunger 22 is not slidably contacted with one surface constituted by the inner peripheral surface of the wall member 28 and the inner peripheral surface of the ferromagnetic cylindrical member 82, and is not contacted with a ferromagnetic material. It has become. For this reason, in the electromagnetic linear valve 10, it is possible to prevent magnetic contact between the plunger 22 and the housing 20 during differential pressure control, and it is possible to reduce the frictional force generated between them. ing.

  The electromagnetic linear valve 10 performs differential pressure control by controlling the balance between the force that urges the plunger 22 upward and the force that urges the plunger 22 downward, and when such frictional force increases. There is a possibility of affecting the differential pressure control. In other words, in the electromagnetic linear valve 10, it is possible to ensure execution of appropriate differential pressure control by the two nonmagnetic cylindrical members 78 and 80. Further, as can be seen from FIG. 1, the electromagnetic linear valve 10 has a symmetrical structure with its axis as the center. For this reason, the attractive force between the plunger 22 and the wall member 28 due to the magnetic flux flowing between the plunger 22 and the wall member 28 becomes substantially uniform in the circumferential direction of the plunger 22, and the friction force can be reduced. It has become. Also from this, it is possible to ensure execution of appropriate differential pressure control.

  On the other hand, the electromagnetic linear valve has a problem of self-excited vibration of the plunger, and friction force generated between the outer peripheral surface of the plunger and the inner peripheral surface of the housing is effective to suppress the self-excited vibration. It is known. For this reason, it is difficult to suppress the self-excited vibration of the plunger only by reducing the frictional force. Therefore, in the electromagnetic linear valve 10, a large electromotive force is generated by electromagnetic induction by disposing the ferromagnetic cylindrical member 82 between the two non-magnetic cylindrical members 78 and 80 for reducing the frictional force. The self-excited vibration of the plunger is suppressed by the electromotive force.

  More specifically, when a conductor moves in a state where magnetic flux flows, a force that tries to prevent the movement of the conductor, that is, an electromotive force is generated due to an electromagnetic induction effect. The electromotive force generated by electromagnetic induction increases as the moving speed of the conductor increases, and does not occur when the conductor is stopped. For this reason, even in the electromagnetic linear valve, the electromotive force is generated if the plunger moves while the magnetic flux flows through the plunger, the housing, etc. when the coil is energized. However, since the electromotive force generated by electromagnetic induction is not generated when the plunger is stopped, and becomes considerably small when the plunger moves at a low speed, it can be considered that the influence on the control of the differential pressure is small. That is, the electromotive force generated by the electromagnetic induction can suitably attenuate the self-excited vibration while ensuring the execution of the differential pressure control.

  The electromotive force generated by the electromagnetic induction depends on the moving speed of the plunger, but also depends on the density of the magnetic flux flowing between the plunger and the housing. In the electromagnetic linear valve 10, as described above, the ferromagnetic cylindrical member 82 is disposed between the two nonmagnetic cylindrical members 78 and 80, and between the plunger 22 and the wall member 28 of the housing 20. The magnetic flux flowing through the magnetic flux flows through the ferromagnetic cylindrical member 82, but hardly flows through the non-magnetic cylindrical member 82. That is, the magnetic flux flowing between the plunger 22 and the wall member 28 of the housing 20 flows densely in the ferromagnetic cylindrical member 82. For this reason, the magnetic flux density can be increased at the position where the ferromagnetic cylindrical member 82 is disposed, and a large electromotive force can be generated. Therefore, according to the electromagnetic linear valve 10, it is possible to suitably attenuate the self-excited vibration while ensuring execution of the differential pressure control.

Modified example

  In the electromagnetic linear valve 10, the ferromagnetic cylindrical member 82 is disposed between the two nonmagnetic cylindrical members 78 and 80 in order to generate a large electromotive force by electromagnetic induction. In the electromagnetic linear valve of the modified example, a non-magnetic and highly conductive member is interposed between the ferromagnetic cylindrical member 82 and the plunger 22 so that a larger electromotive force can be generated. ing. Since the electromagnetic linear valve of the modified example is a member in which a new member is disposed in the circumferential recess 84 of the plunger 22 of the electromagnetic linear valve 10, the explanation of the electromagnetic linear valve of the modified example is as shown in FIG. 3 that is an enlarged view corresponding to FIG. 3 will be described mainly with respect to the newly disposed members, and the same reference numerals will be used for the components having similar functions, and description thereof will be omitted or simplified. To do.

  In the circumferential concave portion 84 of the plunger 22 provided in the electromagnetic linear valve 120 of the modified example, a nonmagnetic and highly conductive member, specifically, copper is deposited, and a cylindrical shape as a conductive nonmagnetic member. The copper thin film 122 is fixed. The surface of the copper thin film 122 and the outer peripheral surface of the plunger 22 are not stepped, that is, are flush with each other, and when the plunger 22 moves, the non-magnetic copper thin film 122 forms the ferromagnetic cylindrical member 82. It comes in sliding contact. For this reason, also in the electromagnetic linear valve 120 of the modified example, the plunger 22 is prevented from coming into contact with a ferromagnetic material, and the differential pressure control is achieved by preventing magnetic contact between the plunger 22 and the housing 20. Can be guaranteed. Further, in the electromagnetic linear valve 120 according to the modified example, the magnetic flux flowing at high density between the plunger 22 and the wall member 28 of the housing 20 through the ferromagnetic cylindrical member 82 causes the copper thin film 122 having high conductivity to flow. Also flows through. For this reason, a current based on electromagnetic induction flows through the copper thin film 122, and a larger electromotive force is easily generated. Therefore, according to the electromagnetic linear valve 170 of the modified example, the self-excited vibration can be more effectively suppressed.

  FIG. 4 shows another electromagnetic linear valve 130 which is another modification of the electromagnetic linear valve 10. Since the electromagnetic linear valve 130 of the modified example has substantially the same configuration as that of the electromagnetic linear valve 10 except for the wall member 132, it will be mainly described, and components having the same functions are denoted by the same reference numerals. The description will be omitted or simplified using.

  The wall member 132 included in the electromagnetic linear valve 130 according to the modified example has a stepped inside. The upper end portion 134 is located at the upper end portion, the lower end portion 136 is located at the lower end portion, and the upper end portion 134. And an intermediate portion 138 having an inner diameter smaller than the inner diameters of the upper end portion 134 and the lower end portion 136. Further, the intermediate portion 138 includes a first intermediate portion 140 located below the upper end portion 134, a second intermediate portion 142 located above the lower end portion 136, and having the same inner diameter as the inner diameter of the first intermediate portion 140. The first intermediate portion 140 and the second intermediate portion 142 are located between the first intermediate portion 140 and the third intermediate portion 144 having an inner diameter smaller than the inner diameter of the first intermediate portion 140 and the second intermediate portion 142. That is, the wall member 132 of the electromagnetic linear valve 130 according to the modified example is shaped such that the inner peripheral surface of the intermediate portion 54 of the wall member 28 of the electromagnetic linear valve 10 protrudes over the entire circumference.

  The nonmagnetic cylindrical member 78 is fixedly fitted to the first intermediate portion 140 of the wall member 132, and the nonmagnetic cylindrical member 80 is fixedly fitted to the second intermediate portion 142. Further, the amount of protrusion of the third intermediate portion 144 from the inner peripheral surface of the first intermediate portion 140 and the second intermediate portion 142, that is, the inner diameter of the first intermediate portion 140 and the second intermediate portion 142, and the third intermediate portion 144 Half of the difference from the inner diameter is the same as the thickness of the nonmagnetic cylindrical members 78 and 80, and the inner peripheral surface of the third intermediate portion 144 and the inner peripheral surface of the nonmagnetic cylindrical members 78 and 80 are flush with each other. Has been. The third cylindrical portion 74 of the plunger 22 is inserted into the inner peripheral surface of the third intermediate portion 144 and the inner peripheral surfaces of the nonmagnetic cylindrical members 78 and 80 that are flush with each other. With such a structure, in the modified electromagnetic linear valve 130, the third cylindrical portion 74 of the plunger 22 is in sliding contact with the inner peripheral surfaces of the nonmagnetic cylindrical members 78 and 80 and the inner peripheral surface of the third intermediate portion 144. And the bottom surface of the circumferential recess 84 formed in the third cylindrical portion 74 of the plunger 22 face each other with a gap. That is, in the electromagnetic linear valve 130 of the modification, the third intermediate portion 144 functions as the ferromagnetic cylindrical member 82 of the electromagnetic linear valve 10, and the differential pressure control is performed in the same manner as the electromagnetic linear valve 10. As a result, the self-excited vibration can be suitably damped. Further, in the electromagnetic linear valve 130 according to the modified example, the ferromagnetic cylindrical member 82 is not required as compared with the electromagnetic linear valve 10 described above, so that the number of components of the electromagnetic linear valve can be reduced by one. Yes.

  FIG. 5 shows an electromagnetic linear valve 150 obtained by further modifying the electromagnetic linear valve 130 of the modified example. The electromagnetic linear valve 150 of the modified example has substantially the same configuration as that of the electromagnetic linear valve 130 of the modified example except for the wall member 152 and the plunger 154. Description of components will be omitted or simplified by using the same reference numerals.

  The wall member 152 included in the electromagnetic linear valve 150 according to the modified example has the same shape as the wall member 132 of the electromagnetic linear valve 130 except for the third intermediate portion 156. The inner diameter of the portion 156 is slightly larger than the inner diameter of the third intermediate portion 144 of the wall member 132 of the electromagnetic linear valve 130. Similarly to the wall member 132 of the electromagnetic linear valve 130, two nonmagnetic cylindrical members 78, 80 are fixedly fitted to the wall member 152. Thereby, the inner peripheral surface of the third intermediate portion 156 is in a state of being recessed from the inner peripheral surfaces of the two nonmagnetic cylindrical members 78 and 80 as shown in FIG.

  Further, the plunger 154 has the same shape as the plunger 22 of the electromagnetic linear valve 130 except for the third cylindrical portion 158, and the outer diameter of the third cylindrical portion 158 is uniform. That is, the plunger 154 has the same shape as the plunger 22 in which the circumferential recess 84 is not formed. The third cylindrical portion 158 of the plunger 154 is inserted into the inner peripheral surface of the third intermediate portion 156 and the inner peripheral surfaces of the nonmagnetic cylindrical members 78 and 80. With such a structure, in the electromagnetic linear valve 150 according to the modified example, the third cylindrical portion 158 of the plunger 154 is in sliding contact with the inner peripheral surfaces of the nonmagnetic cylindrical members 78 and 80 and the third intermediate portion 156 of the wall member 152. And the outer peripheral surface of the third cylindrical portion 158 of the plunger 154 face each other with a gap. Incidentally, the gap, that is, the shortest distance between the inner circumferential surface of the third intermediate portion 156 and the outer circumferential surface of the third cylindrical portion 158 of the plunger 154 is the circumferential distance formed on the plunger 22 of the electromagnetic linear valve 130. The depth is the same as the depth of the directional recess 84, and in FIG. 5, the gap is exaggerated in order to clarify that the plunger 154 and the wall member 152 do not contact each other. With such a structure, the electromagnetic linear valve 150 according to the modified example can suitably attenuate the self-excited vibration while ensuring the execution of the differential pressure control, similarly to the electromagnetic linear valve 130 described above. Yes. Furthermore, in the electromagnetic linear valve 150 according to the modified example, it is not necessary to form a circumferential recess on the outer peripheral surface of the plunger as compared with the electromagnetic linear valve 130. Therefore, the manufacturing process of the electromagnetic linear valve is simplified. It is possible.

  Incidentally, in the electromagnetic linear valves 10, 120, 130, 150 of the above-described embodiments and modifications, the two nonmagnetic cylindrical members 78, 80 are fixed to the inner peripheral surfaces of the wall members 28, 132, 152 of the housing 20. However, as with the electromagnetic linear valves 10, 120, 130, and 150, the self-excited vibration is preferably achieved while securing the execution of the differential pressure control by fixing the plungers 22 and 154 to the outer peripheral surface. It is possible to attenuate. In such a configuration, the ferromagnetic cylindrical member 82 is fixed to the outer peripheral surface of the plunger 22, and the portions corresponding to the portions 144, 156 protruding in the radial direction of the wall members 132, 152 are replaced with the plunger 22, 154 needs to be formed on the outer peripheral surface. Moreover, it is necessary to form what corresponds to the circumferential recessed part 84 formed in the outer peripheral surface of the plunger 22 on the inner peripheral surface of the wall members 28 and 132 of the housing 20.

  10: Electromagnetic linear valve 20: Housing 22: Plunger 24: Coil 26: Core (core part) 28: Wall member (housing cylinder part) (main body) 30: Valve member (partition part) 58: First liquid chamber 60: Second liquid chamber 62: Through hole 64: Opening 78: Nonmagnetic cylindrical member (liner) 80: Nonmagnetic cylindrical member (liner) 82: Ferromagnetic cylindrical member (housing cylindrical portion) (cylindrical member) 106: Compression coil spring (Elastic body) 120: Electromagnetic linear valve 122: Copper thin film (conductive nonmagnetic member) 130: Electromagnetic linear valve 132: Wall member (housing cylinder part) 150: Electromagnetic linear valve 152: Wall member (housing cylinder part) 154: Plunger

Claims (7)

(a) a cylindrical housing cylinder, (b) a core that closes one end of the housing cylinder, and (c) a first liquid chamber that is located inside the housing cylinder on the side of the core. A partition part that is partitioned into a second liquid chamber located on the opposite side of the core part, and has a through-hole penetrating the first liquid chamber and the second liquid chamber so as to communicate with each other; d) a housing having an outflow port in communication with the first liquid chamber; and (e) an inflow port in communication with the second liquid chamber;
A plunger, one end of which is disposed in the first liquid chamber so as to be movable in the axial direction with the other end facing the opening of the through hole, and a plunger which can be seated in the opening at the other end; ,
An elastic body that biases the plunger in one of a direction in which the other end of the plunger approaches the opening of the through hole and a direction in which the other end of the plunger separates from the opening;
An electromagnetic linear valve comprising: a coil provided around the housing and forming a magnetic field for moving the plunger in a direction opposite to a direction in which the elastic body biases the plunger;
The electromagnetic linear valve
Interposed between the inner peripheral surface of the housing cylindrical portion and the outer peripheral surface of the plunger, and fixed to one of the two surfaces in a state of being separated from each other in the axial direction. An electromagnetic system comprising two non-magnetic liners that are in sliding contact with the other surface that is the other of the peripheral surface and the outer peripheral surface of the plunger, and the one surface and the other surface facing each other without contact between the two liners Linear valve.   The electromagnetic linear valve according to claim 1, wherein each of the two liners has a cylindrical shape.   In a state where the two liners are in sliding contact with the other surface, the distance between the one surface and the other surface facing each other between the two liners is 1 / th of the radial thickness of the two liners. The electromagnetic linear valve according to claim 2, which is 600 or more and 1/10 or less. One of the housing tube portion having the one surface and the plunger is
The main body and a cylindrical member fixedly fitted to the main body are formed into a stepped shape, and the surface of the cylindrical member opposite to the surface in contact with the main body is the one surface. The electromagnetic linear valve according to claim 2 or 3, wherein the electromagnetic linear valve functions as a part and is fixedly fitted to the main body so that the two liners sandwich the cylindrical member. The one side is
The electromagnetic linear valve according to any one of claims 1 to 3, wherein the electromagnetic linear valve protrudes over the entire circumference toward the other surface between the two liners. The other side is
6. The electromagnetic linear valve according to claim 1, wherein the electromagnetic linear valve is recessed over the entire circumference at a position facing the portion between the two liners on the one surface. The electromagnetic linear valve
The electromagnetic linear valve according to claim 6, further comprising a conductive nonmagnetic member that is disposed in a portion that is recessed over the entire circumference of the other surface and is formed of a nonmagnetic and highly conductive material.

Images