JP5673011B2 - Solenoid linear valve - Google Patents

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.

  In the electromagnetic linear valve, (a) the interior is divided into a first liquid chamber and a second liquid chamber, and a through-hole is formed to penetrate the first liquid chamber and the second liquid chamber so as to communicate with each other. (B) a first liquid chamber having a through hole that is movable in the axial direction and functions as a valve seat along with the movement in the axial direction. There is an electromagnetic linear valve provided with a plunger disposed in a first liquid chamber so that one end functioning as a valve body closes the opening to the first liquid chamber. Such an electromagnetic linear valve having a plunger and a housing prohibits the flow of hydraulic fluid from the hydraulic fluid path on the high pressure side to the hydraulic fluid path on the low pressure side when the valve element is blocking the valve seat. In a state where a gap is generated between the valve body and 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 2001-208233 A JP 2003-130247 A JP 2007-55521 A

  In the electromagnetic linear valve having the above structure, since the plunger is supported by the elastic body in the housing, there is a possibility that self-excited vibration may occur with the opening and closing of the valve. Various factors have been considered as the cause of the self-excited vibration of the plunger. For example, the action of the hydraulic fluid flowing into the housing from the high-pressure side hydraulic fluid path to the plunger is one of the factors causing the self-excited vibration. It is considered as one. For this reason, it is not desirable for the hydraulic fluid to flow into the housing from the high-pressure side hydraulic fluid passage. This invention is made in view of such a situation, and it is a subject to provide the electromagnetic linear valve which can suppress that a hydraulic fluid flows in into a housing vigorously from the hydraulic fluid path of a high voltage | pressure side. To do.

In order to solve the above problems, an electromagnetic linear valve according to the present invention includes: (a) a main body portion formed of a ferromagnetic material, and an outer diameter smaller than the outer diameter of the main body portion, and one end portion of the main body portion. A plunger having a rod portion extending from the tip and functioning as a valve body; and (b) a plunger main body cover that is formed of a ferromagnetic material and into which the plunger main body portion is inserted with clearance. An electromagnetic linear valve provided with a housing having an insertion portion, wherein one of the plunger main body portion and the plunger main body portion insertion portion of the housing has one end and the other end of the plunger main body portion in the plunger axial direction. together positioned between the parts, have a clearance smallest minimum clearance portion between the main body and the plunger body portion insertion member, the plunger main body to be inserted The inner peripheral surface of the main body portion has two tapered surfaces whose inner diameter increases from a certain portion toward both ends, or the outer peripheral surface of the main body portion has an outer diameter from the certain portion toward both ends. By forming the two tapered surfaces so as to be small, the certain portion functions as the minimum clearance portion .

  In the electromagnetic linear valve of the present invention, in the state where the tip of the rod portion is seated on the opening of the through hole, that is, in the state where it is in contact with the partition portion where the through hole is formed, One of the plunger body portion insertion portion contacts the other at the minimum clearance portion. For this reason, it is possible to tilt the plunger within the housing with the minimum clearance portion as a fulcrum in a state where the tip of the rod portion is seated in the opening of the through hole. That is, it is possible to change the size of the gap between the tip of the rod part and the opening, that is, the valve opening amount, without separating the tip of the rod part from the opening. Therefore, according to the electromagnetic linear valve of the present invention, it is possible to gradually change the size of the gap between the tip of the rod portion and the opening, and the hydraulic fluid is vigorously moved from the high-pressure side hydraulic fluid passage. It is possible to suppress the flow into the.

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.

The following item (0) is a term relating to an aspect indicating a configuration that is a premise of the claimable invention, and the technical feature described in any of the following terms is added to the aspect of the term. Aspects are aspects of the claimable invention. Incidentally, the item (1), in which the item (0) is cited , is added with the technical feature described in the item (8) and the technical feature described in the item (9) alternatively. The technical feature described in (2) is added to claim 1 in claim 2, and the technical feature described in (3) is added in claim 2 to claim 3. The technical feature described in (4) and (5) is added to claim 3 in claim 4, and in any one of claims 1 to 4, the technology described in (7). The technical feature is added to claim 5, the technical feature described in (8) is added to any one of claims 1 to 5, and claim 6 to claim 1 to claim 5. The technical feature described in the item (9) is added to any one of the items 5 to 7, and the item (21) is added to any one of the items 1 to 7. The technical features described above are added to claim 8, and the technical features described in claims (22) and (23) are added to claim 8 in claims 9 and (24). The technical features described in the item (8) correspond to the items (10), respectively.

(0) (a) A partition section in which the interior is partitioned into a first liquid chamber and a second liquid chamber, and a through-hole penetrating through the first liquid chamber and the second liquid chamber is formed so as to communicate with each other. And (b) an outflow port communicating with the first liquid chamber, and (c) an inflow port communicating with the second liquid chamber, and a housing filled with hydraulic fluid;
(A) A main body formed of a ferromagnetic material, and (B) a rod having an outer diameter smaller than the outer diameter of the main body, extending from one end of the main body, and the tip functioning as a valve body The tip of the rod portion closes the opening to the first liquid chamber of the through hole that functions as a valve seat with the movement in the axial direction. A plunger disposed in the first liquid chamber,
An elastic body that urges the plunger in one of a direction in which the distal end portion of the rod portion approaches the opening of the through hole and a direction away from the opening;
An electromagnetic linear valve provided with 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 aspect described in this section is an aspect that constitutes a premise of the claimable invention, and is an aspect in which basic components of the electromagnetic linear valve of the claimable invention are listed. In the electromagnetic linear valve described in this section, when the valve body is seated on the valve seat and the valve body is blocking the valve seat, the hydraulic fluid path from the high pressure side to the hydraulic fluid path on the low pressure side is used. The flow of the hydraulic fluid is prohibited, and the flow of the hydraulic fluid from the hydraulic fluid passage on the high pressure side to the hydraulic fluid passage on the low pressure side is allowed in a state where a gap is generated between the valve body and the valve seat. Incidentally, the “sitting state” in the present specification includes not only a state in which the valve body blocks the valve seat but also a state in which the valve body is in contact with the valve seat. That is, the “sitting state” in this specification includes a state in which the valve body is in contact with the valve seat and a gap is generated between the valve body and the valve seat.

(1) The housing is
It is formed of a ferromagnetic material, and has a plunger main body insertion portion into which the main body portion of the plunger is inserted with a clearance,
One of the plunger body portion and the plunger body portion insertion portion,
(0) Item having a minimum clearance portion located between one end portion and the other end portion of the main body portion in the axial direction of the plunger and having the smallest clearance between the main body portion and the inserted plunger main body portion. The electromagnetic linear valve described in 1.

  In the electromagnetic linear valve, since the plunger is supported by an elastic body in the housing, there is a possibility that self-excited vibration may occur as the valve opens and closes. Various factors have been considered as the cause of the self-excited vibration of the plunger. For example, the action of the hydraulic fluid flowing into the housing from the high-pressure side hydraulic fluid path to the plunger is one of the factors causing the self-excited vibration. It is considered as one. For this reason, it is not desirable for the hydraulic fluid to flow into the housing vigorously from the hydraulic fluid path on the high pressure side, and a rapid increase in the gap between the valve body and the valve seat, that is, the valve opening amount is not desirable.

  For example, in an electromagnetic linear valve in which the plunger is inserted with almost no play in the housing, the valve element is separated from the valve seat from the state where the valve element closes the valve seat by energizing the coil. The valve opening amount tends to increase rapidly. On the other hand, in an electromagnetic linear valve in which a plunger is inserted with a relatively large backlash in the housing, the valve element is first closed from the state where the valve element closes the valve seat by energizing the coil. Although it is in contact with the seat, the valve body is switched to a state where a gap is formed between the valve body and the valve seat, and the valve body is switched to a state where the valve body is separated from the valve seat. In other words, in an electromagnetic linear valve in which the plunger is inserted with a relatively large backlash in the housing, the gap between the valve body and the valve seat can be gradually increased, and the valve opening amount increases rapidly. Can be suppressed. However, it is desirable that the backlash of the plunger in the housing is small.

  In view of the above, in the electromagnetic linear valve described in this section, one of the plunger body portion and the plunger body portion insertion portion of the housing (hereinafter sometimes abbreviated as “insertion portion”) is In addition, it has a minimum clearance portion that is located between one end portion and the other end portion of the main body portion in the axial direction of the plunger and has the smallest clearance between the main body portion and the inserted portion. In the electromagnetic linear valve described in this section, normally, one of the plunger main body and the inserted portion of the housing is in contact with the other at the minimum clearance in a state where the valve body closes the valve seat. For this reason, it is possible to tilt the plunger within the housing from the state in which the valve body closes the valve seat, with the minimum clearance portion as a fulcrum, and without separating the valve body from the valve seat, It is possible to create a gap between the valve body and the valve seat. Further, since the plunger main body portion and the inserted portion of the housing are in contact with each other at the minimum clearance portion, rattling of the plunger in the housing is reduced. Therefore, according to the electromagnetic linear valve described in this section, the sudden increase in the valve opening amount is suppressed without increasing the backlash of the plunger in the housing, and the hydraulic fluid is vigorously supplied from the high pressure side hydraulic fluid passage. It is possible to suppress the inflow into the housing.

(2) The electromagnetic linear valve
The plunger in a state where one of the plunger main body portion and the plunger main body insertion portion of the housing is in contact with the other in the minimum clearance portion, and the tip of the rod portion is seated in the opening. The electromagnetic linear valve according to item (1), wherein the valve opening amount is increased as the inclination angle of the axis of the housing with respect to the axis of the housing increases.

  In the electromagnetic linear valve described in this section, the operation of the plunger when the valve is opened is specifically limited. According to the electromagnetic linear valve described in this section, the plunger can be tilted within the housing with the minimum clearance portion as a fulcrum, and the valve opening amount can be gradually increased.

(3) The housing is
(a) a core portion made of a ferromagnetic material and facing an end surface on the other end side of the main body portion of the plunger; and (b) the core portion and the plunger main body portion insertion portion. And a connecting portion that connects in a state where no magnetic flux flows between them,
The electromagnetic linear valve according to item (2), wherein a part of the plunger facing the connecting portion is configured to abut on the connecting portion by increasing the inclination angle.

  In an electromagnetic linear valve, usually, a magnetic flux flows between the core portion of the housing and the plunger, so that the plunger is moved against the elastic force. For this reason, when the plunger is excessively inclined in the housing, the end face of the core portion and the end face of the plunger facing the end face do not face each other, and the magnetic resistance between the two end faces increases, thereby moving the plunger. The power for this will be reduced. In the electromagnetic linear valve described in this section, when the inclination angle of the plunger is increased to some extent, in other words, when the inclination angle of the plunger becomes the set angle, a part of the plunger comes into contact with the connecting portion of the housing. . Therefore, according to the electromagnetic linear valve described in this section, it is possible to prohibit excessive inclination of the plunger.

  The “core portion”, “connecting portion”, and “plunger main body inserted portion” described in this section may be integrally formed from a single material, each of which is an individual member. It may be done. Specifically, when integrally molded from a single material, for example, a core portion, a connecting portion, and at least a portion continuous with the connecting portion of the inserted portion are made of a single material made of a ferromagnetic material. In addition, the connecting portion may be made non-magnetic. In addition, when each is a separate member, for example, as will be described in detail later, a member made of a non-magnetic material is allowed to function as a connecting portion, and a member that functions as a core portion is covered with the member. A member that functions as an insertion portion may be connected.

  (4) The plunger has a protruding portion formed on the outer peripheral surface of the other end portion of the main body, and the protruding portion is configured to contact the connecting portion by increasing the inclination angle. (3) The electromagnetic linear valve described in the item (3).

(5) The connecting portion is
The core portion is formed of a non-magnetic material and is externally fitted to the core portion and the plunger body portion insertion portion, and the end surface of the core portion and the end surface of the plunger body portion insertion portion are separated from each other. And a member connecting the plunger body portion insertion portion,
The protrusion is positioned between an end surface of the core portion and an end surface of the plunger body portion insertion portion, and is configured to contact the connecting portion by increasing the inclination angle (4). The electromagnetic linear valve described in 1.

  In the electromagnetic linear valve described in the above two terms, the structure of the portion that contacts the connecting portion of the plunger is specifically limited. In the electromagnetic linear valve described in the latter term, the structure of the housing is limited. It is specifically limited. The housing described in the latter section has a shape in which a recess is formed on the inner peripheral surface so as to extend in the circumferential direction, and the bottom of the recess functions as a connecting portion. In the electromagnetic linear valve described in the latter section, the protruding portion of the plunger is located in the recess, and the protruding portion can be suitably brought into contact with the bottom of the recess. In addition, the “projection part” described in the above two items may be formed over the entire circumference of the outer peripheral surface of the main body part, specifically, for example, an annular flange part. A part of the part may be cut out. As will be described in detail later, the cutout portion facilitates the flow of the working fluid, thereby facilitating the discharge of bubbles from the first liquid chamber.

  (6) In a state where one of the main body portion of the plunger and the plunger main body portion insertion portion of the housing is in contact with the other in the minimum clearance portion, a part of the plunger comes into contact with the connecting portion. The electromagnetic linear valve according to any one of (3) to (5), wherein the tip of the rod portion is sometimes separated from the partition portion.

  In the electromagnetic linear valve described in this section, in the state where the tip of the rod portion is separated from the partition portion, that is, in the state where the valve body is separated from the valve seat, the plunger main body portion and the inserted portion of the housing One is in contact with the other in the minimum clearance portion, and a part of the plunger is in contact with the connecting portion of the housing. In addition, as described above, the coupling portion prevents the magnetic flux from flowing. That is, the plunger is supported at two points in the housing in a separated state, and the connecting portion which is one of the two support points is a non-magnetic portion. The amount of magnetic flux flowing in the contact portion between the plunger and the housing is largely related to the frictional force generated between the plunger and the housing, and the frictional force decreases as the amount of magnetic flux flowing in the contact portion decreases. Therefore, according to the electromagnetic linear valve described in this section, it is possible to reduce the frictional force generated between the plunger and the housing in a separated state, and to ensure smooth movement of the plunger. It becomes.

(7) The main body portion of the plunger is (a) a small diameter portion that is located on the rod portion side and is formed of a ferromagnetic material, and (b) a side of the rod portion that is continuous with the small diameter portion. Is located on the opposite side and consists of a large diameter part made of a ferromagnetic material,
The plunger main body insertion portion of the housing includes (a) a small inner diameter portion in which the small diameter portion is inserted and formed of a ferromagnetic material, and (b) continuous with the small inner diameter portion. The inner diameter is larger than the inner diameter, the large diameter portion is inserted, and consists of a large inner diameter portion formed of a ferromagnetic material,
The electromagnetic linear valve according to any one of (1) to (6), wherein one of the small diameter portion and the small inner diameter portion has the minimum clearance portion.

  In the electromagnetic linear valve described in this section, the outer diameter of the small-diameter portion of the plunger is smaller than the outer diameter of the large-diameter portion so that the cross-sectional area of the plunger changes suddenly between the large-diameter portion and the small-diameter portion. It has become. And the minimum clearance part is provided in the small diameter part or the small internal diameter part of the housing in which a small diameter part is inserted. For this reason, magnetic saturation occurs in the small diameter portion of the plunger, and the amount of magnetic flux flowing through the contact portion between the plunger and the inner peripheral surface of the housing, that is, the minimum clearance portion, is smaller than the amount of all magnetic flux flowing through the plunger. Yes. Therefore, according to the electromagnetic linear valve described in this section, it is possible to reduce the frictional force generated between the plunger and the housing, and to ensure the smooth movement of the plunger.

  (8) The inner peripheral surface of the plunger body portion insertion portion is two tapered surfaces whose inner diameter increases from a certain portion toward both ends, and the certain portion is the minimum clearance portion. The electromagnetic linear valve according to any one of items (1) to (7), which functions as:

  (9) Since the outer peripheral surface of the main body portion has two tapered surfaces such that the outer diameter decreases from a certain portion toward both ends, the certain portion functions as the minimum clearance portion ( The electromagnetic linear valve according to any one of items 1) to (7).

  (10) The main body portion has a portion protruding in the radial direction over the entire circumference on the outer peripheral surface between the one end portion and the other end portion, and the protruding portion functions as the minimum clearance portion. Or the electromagnetic linear valve as described in any one of (7) term.

  In the electromagnetic linear valve described in the above three terms, the shape of the minimum clearance portion is specifically limited. The “tapered surface” described in the first and second terms may be formed toward the end of the outer peripheral surface of the main body or the inner peripheral surface of the inserted portion. It may not be formed. That is, the tapered surface may be formed on the outer peripheral surface of the main body portion or a part of the inner peripheral surface of the inserted portion, or may be formed on the entire surface. In addition, the “projecting portion” described in the third item may be a single member or may be formed on the outer peripheral surface of the main body. That is, for example, the main body portion may be configured by a cylindrical member and an annular member that is externally fitted to the cylindrical member, and the annular member may function as a minimum clearance portion. A single member having a generally cylindrical shape in which a part of the outer diameter between the other end portion is increased may be used.

(11) The elastic body is
The electromagnetic linear valve according to any one of (1) to (10), wherein the plunger is biased in a direction in which a tip portion of the rod portion approaches the opening.

  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 occurrence of self-excited vibration of the plunger is sufficiently utilized.

(21) The housing is
Formed of a ferromagnetic material, and having a core portion facing the end surface on the other end side of the main body portion of the plunger;
The main body is
A bottomed hole formed on the end surface on the other end side and opening toward the core, and a through passage opening in the bottomed hole and on the outer peripheral surface of the main body,
The elastic body is
A compression coil spring that is disposed in the bottomed hole in a compressed state by the bottom of the bottomed hole and the core, and biases the plunger in a direction in which the tip of the rod portion approaches the opening. The electromagnetic linear valve according to any one of items (0) to (11).

  The cause of the self-excited vibration of the plunger is not only the action of the hydraulic fluid flowing into the housing from the high-pressure side hydraulic fluid path to the plunger, but also the decrease in the damping force with respect to the movement of the plunger is a cause of the self-excited vibration. It is considered as one. When the plunger is moved, the plunger is attenuated by the hydraulic fluid in the first liquid chamber in which the plunger is disposed. However, if air bubbles enter the first liquid chamber, the damping effect by the hydraulic fluid may be reduced. There is. In particular, when air bubbles enter the spring chamber, which is a liquid chamber defined by the core portion and the end of the plunger facing the core portion, the air bubbles are moved by the plunger and the core portion as the plunger moves. There is a possibility that the damping effect by the hydraulic fluid may be reduced due to being sandwiched and compressed. For this reason, when air bubbles enter the spring chamber, it is desirable to quickly discharge the air bubbles from the spring chamber. However, the spring chamber is usually provided with a bottomed hole that accommodates a compression coil spring as an elastic body, and if a bubble enters the bottomed hole, the bubble is discharged outside the spring chamber. It is difficult.

  In view of the above, in the electromagnetic linear valve described in this section, a penetrating path that opens to the inside of the bottomed hole and the outer peripheral surface of the plunger is formed in the plunger. Therefore, according to the electromagnetic linear valve described in this section, air bubbles inside the bottomed hole are placed between the outer peripheral surface of the plunger and the inner peripheral surface of the housing, that is, outside the spring chamber, through the through passage. It becomes possible to discharge | emit and it becomes possible to suppress generation | occurrence | production of a self-excited vibration.

(22) The first liquid chamber is
(a) a valve chamber defined by an end surface of the plunger on one end portion side and the partition portion of the housing, and present around the rod portion and communicating with the outflow port; b) including a plunger chamber positioned on the other end side of the main body from the valve chamber,
The plunger is
The electromagnetic linear valve according to item (21), further comprising a communication passage that communicates the valve chamber and the plunger chamber.

  Even if the bubbles are discharged from the spring chamber, there is a possibility that the discharged bubbles may enter the spring chamber again if the discharged bubbles are not discharged from the first liquid chamber to the hydraulic fluid path on the low pressure side. In the electromagnetic linear valve described in this section, the valve chamber in which the low-pressure side hydraulic fluid passage opens and the plunger chamber are communicated with each other so that the bubbles can be easily discharged to the low-pressure hydraulic fluid passage. Therefore, according to the electromagnetic linear valve described in this section, it is possible to suppress the bubbles discharged from the spring chamber from entering the spring chamber again.

  (23) The electromagnetic linear valve according to (22), wherein the electromagnetic linear valve is configured such that the through-passage and the communication passage do not intersect.

  In the electromagnetic linear valve described in this section, the flow path of hydraulic fluid from the valve chamber to the spring chamber is different from the flow path of hydraulic fluid from the bottomed hole provided in the spring chamber to the outside of the spring chamber. It becomes possible to make it. Specifically, the hydraulic fluid in the valve chamber flows into the plunger chamber through the communication path, and the hydraulic fluid that has flowed into the plunger chamber flows into the spring chamber. Then, the hydraulic fluid that has flowed into the spring chamber flows into the bottomed hole and is discharged to the outside of the spring chamber through the through passage. As described above, the working fluid circulates in the first fluid chamber, whereby the bubbles in the bottomed hole can be suitably discharged to the working fluid path on the low pressure side. Incidentally, the “through passage” and “communication passage” described in this section may be any one in which one of the passage passage and the communication passage does not open to the other, and may be positioned in different phases in the circumferential direction of the plunger. That's fine. That is, the “penetrating passage” and the “communication passage” may cross three-dimensionally, for example.

(24) The housing is
It is formed of a ferromagnetic material, and has a plunger main body insertion portion into which the main body portion of the plunger is inserted with a clearance,
One of the plunger body portion and the plunger body portion insertion portion,
In the axial direction of the plunger is located between one end and the other end of the main body, and has a minimum clearance portion where the clearance between the main body and the plunger main body insertion portion is the smallest,
The electromagnetic linear valve according to (22) or (23), wherein the valve chamber and the plunger chamber are positioned with the minimum clearance portion interposed therebetween.

  If there is a narrow portion between the outer peripheral surface of the plunger and the inner peripheral surface of the housing, the flow of hydraulic fluid between the spring chamber and the valve chamber is difficult to be smooth. In the electromagnetic linear valve described in this section, the valve chamber and the plunger chamber located with the minimum clearance portion interposed therebetween are communicated with each other by a communication path. Therefore, according to the electromagnetic linear valve described in this section, it becomes possible to make the flow of the hydraulic fluid between the spring chamber and the valve chamber smooth, and the flow of the hydraulic fluid from the spring chamber to the low pressure side It becomes easy to discharge into the hydraulic fluid path.

It is a schematic sectional drawing which shows the electromagnetic linear valve which is an Example of claimable invention. It is a figure which shows the flow of the magnetic flux in the electromagnetic type linear valve of FIG. 1, and the magnetic force which urges | biases a plunger. It is a schematic sectional drawing which shows the electromagnetic type linear valve of a modification. It is a schematic sectional drawing which shows the electromagnetic linear valve of another modification. It is a schematic sectional drawing which shows the electromagnetic linear valve of another modification.

  Hereinafter, embodiments of the claimable invention and some modifications 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 columnar core 26 provided at the upper end portion, a generally cylindrical wall member 28 constituting a wall surface, and a covered cylindrical valve member 30 fitted into the lower end portion of the wall member 28. Have. 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 interior of the wall member 28 is stepped, and includes an upper end 50 positioned at the upper end, a first intermediate having an inner diameter smaller than the inner diameter of the upper end 50 and positioned below the upper end 50. It can be divided into a part 52, a second intermediate part 54 having an inner diameter smaller than the inner diameter of the first intermediate part 52, and a lower end part 56 located at the lower end part. . A valve member 30 as a partition portion is fixedly inserted into the lower end portion 56, 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. 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. 2 located below the cylindrical portion 72 and having an outer diameter smaller than the outer diameter of the second cylindrical portion 72, and an outer diameter located below the contacting portion 74 and smaller than the outer diameter of the contacting portion 74. And a stepped shape. Incidentally, the first cylindrical portion 70, the second cylindrical portion 72, and the contact portion 74 constitute a main body portion of the plunger 22.

  The first cylindrical portion 70 of the plunger 22 is provided so as to face the core 26 as the core portion, and is inserted into the upper end portion 50 of the wall member 28, and the second cylindrical portion 72 is connected to the first intermediate portion 52. The contact portions 74 are inserted into the second intermediate portion 54, respectively. That is, the main body portion of the plunger 22 is inserted into the plunger main body portion insertion portion configured by the upper end portion 50 of the wall member 28, the first intermediate portion 52, and the second intermediate portion 54. The outer diameters of the first cylindrical portion 70, the second cylindrical portion 72, and the contact portion 74 of the plunger 22 are the inner diameters of the upper end portion 50, the first intermediate portion 52, and the second intermediate portion 54 of the wall member 28, respectively. The plunger 22 is made slightly smaller so that the plunger 22 can smoothly move in the axial direction in the housing 20.

  The inner peripheral surface of the second intermediate portion 54 as the small inner diameter portion into which the contact portion 74 as the small diameter portion is inserted has a tapered shape in which the inner diameter increases as the inner diameter decreases downward. The step surface between the intermediate portion 54 and the first intermediate portion 52 has a tapered shape in which the inner diameter increases as the inner diameter increases upward. On the other hand, the outer peripheral surface of the contact portion 74 has a tapered shape that decreases as the outer diameter thereof decreases downward. Further, the outer diameters of the first cylindrical portion 70 and the second cylindrical portion 72 and the inner diameters of the upper end portion 50 and the first intermediate portion 52 are substantially uniform, and the first cylindrical portion 70 and the upper end portion 50 are made uniform. And the clearance between the second cylindrical portion 72 as the large diameter portion and the first intermediate portion 52 as the large inner diameter portion are the lower end portion of the contact portion 74 and the lower end portion of the second intermediate portion 54. The clearance between is almost the same. That is, the clearance between the plunger 22 and the wall member 28 is the smallest between the upper end portion of the contact portion 74 and the upper end portion of the second intermediate portion 54. In FIG. 1, each clearance is exaggerated in order to clarify the difference in clearance.

  With such a structure, when the axis of the plunger 22 and the axis of the housing 20 are misaligned, the plunger 22 and the wall member 28 of the housing 20 come into contact with the upper end portion of the second intermediate portion 54 as the minimum clearance portion. Contact is made with the upper end of the portion 74. A convex portion 78 is formed on the upper end surface of the first cylindrical portion 70 of the plunger 22, and the convex portion 78 is inserted into a concave portion 80 formed on the lower end surface of the core 26. Further, a flange portion 82 is formed on the outer peripheral surface of the upper end of the first cylindrical portion 70, and the flange portion 82 extends between the outer edge portion of the lower end surface of the core 26 and the upper end surface of the wall member 28. I'm out.

  A cutout 84 is formed on the outer circumferential surface of the contact portion 74 so as to extend in the axial direction at one place in the circumferential direction, and the two liquid chambers in the first liquid chamber 58 are communicated with each other by the cutout 84. ing. Specifically, the first liquid chamber 58 includes a step surface between the first plunger liquid chamber 86 defined by the core 26 and the upper end surface of the wall member 28, and the first cylindrical portion 70 and the second cylindrical portion 72. And the second plunger liquid chamber 88 defined by the step surface between the upper end portion 50 of the wall member 28 and the first intermediate portion 52, the step surface between the second cylindrical portion 72 and the contact portion 74, and the first step surface. The third plunger liquid chamber 90 defined by the step surface between the first intermediate portion 52 and the second intermediate portion 54, the step surface between the second intermediate portion 54 and the lower end portion 56, and the valve member 30. It is comprised by four liquid chambers with the 4th plunger liquid chamber 92 divided. Of the four liquid chambers, the third plunger liquid chamber 90 and the fourth plunger liquid chamber 92 are communicated with each other by a notch 84. Incidentally, the fourth plunger liquid chamber 92 is opened in the outer wall surface of the lower end portion 56 of the wall member 28, and the opening functions as an outflow port, so that the low pressure side hydraulic fluid path 14 is connected to the fourth plunger liquid chamber 92. That is, it is connected to the first liquid chamber 58.

  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 through hole 62 can be closed by the lower end of the rod portion 66 functioning as the valve body being seated in the opening 64 functioning as the valve seat. Incidentally, the plunger 22 is formed by processing a single material made of a ferromagnetic material. In the plunger 22 formed from one material, surface heat treatment for increasing the surface hardness, specifically, carburizing and quenching treatment is applied to the entire surface. The hardness of the lower end of the rod portion 76 seated in the opening 64 is increased.

  A bottomed hole 100 is formed in the upper end surface of the plunger 22, and a compression coil spring 102 is inserted into the bottomed hole 100. The upper end portion of the compression coil spring 102 protrudes from the upper end surface of the plunger 22, and the compression coil spring 102 is disposed in a compressed state by the bottom surface of the recess 80 formed in the core 26 and the bottom surface of the bottomed hole 100. Has been. For this reason, the plunger 22 is urged in a direction away from the core 26 by the elastic force of the compression coil spring 102 as an elastic body. That is, the lower end of the rod portion 76 of the plunger 22 is biased in a direction approaching the opening 64 (hereinafter also referred to as “approach direction”). Furthermore, a through passage 104 is formed in the plunger 22 so as to extend in the radial direction from the inside of the bottomed hole 100. The through passage 104 opens to the outer peripheral surface of the second cylindrical portion 72 of the plunger 22, and communicates the inside of the bottomed hole 100 and the second plunger liquid chamber 88. A rod-like stopper 106 is inserted into the bottomed hole 100 so as to be surrounded by the compression coil spring 102, and the amount of upward movement of the plunger 22 is limited by the stopper 106.

  The coil 24 is held at the outer periphery of the housing 20 by a resin holding member 107 and is covered with a coil case 108 made of a ferromagnetic material together with the holding member 107. The coil case 108 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 108, 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 high-pressure side hydraulic fluid path 12 by the elastic force of the compression coil spring 102. By closing 64, the electromagnetic linear valve 10 prohibits 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. 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 102 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 108, 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 102 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, the electromagnetic linear valve 10 controls the balance between the force that urges the plunger 22 upward and the force that urges the plunger 22 downward, so that the low pressure side hydraulic fluid pressure and the high pressure side hydraulic fluid pressure are controlled. The pressure difference is controlled, and the force that urges the plunger 22 upward and the force that urges the plunger 22 downward may be approximately the same. Further, since the plunger 22 is elastically supported in the housing 20 by the spring 102, the problem that the plunger 22 vibrates at a specific frequency depending on the spring constant of the spring 102, so-called plunger 22 itself. There is a problem of excitation vibration. Various factors such as an action on the plunger of the hydraulic fluid that vigorously flows into the housing from the inflow port are considered as the generation factors of the self-excited vibration. In particular, when the opening 64 of the through hole 62 is switched from the state where the opening 64 is blocked by the tip of the rod portion 76 to the state where the working fluid flows through the opening 64, that is, the initial flow of the working fluid into the first liquid chamber 58. Occasionally, when the gap in which the working fluid flows from the second fluid chamber 60 to the first fluid chamber 58 through the opening 64, in other words, the gap between the tip of the rod portion 76 and the opening 64 suddenly expands, the working fluid becomes vigorous. Acting on the plunger, the self-excited vibration of the plunger 22 is likely to occur.

  Therefore, in the electromagnetic linear valve 10, the hydraulic fluid flows in a state where the tip of the rod portion 76 is in contact with the opening 64 at the initial stage of inflow of the hydraulic fluid into the first fluid chamber 58. The gap between the tip and the opening 64 is prevented from suddenly expanding. Specifically, when the plunger 22 is biased in the approaching direction by the compression coil spring 102, the axis of the plunger 22 is aligned with the axis of the housing 20 when the tip of the rod portion 76 blocks the opening 64 of the through hole 62. The plunger 22 is in contact with the upper end portion of the second intermediate portion 54 of the wall member 28 in a state tilted with respect to the wall member 28. That is, the plunger 22 is supported at two points in the housing 20 at the opening 64 and the upper end portion of the second intermediate portion 54 of the wall member 28 when the valve is closed.

  In this state, when a current is supplied to the coil 24, the magnetic flux is generated from the outer edge of the concave portion 80 of the core 26 to the outer edge of the convex portion 78 of the plunger 22 as shown in FIG. Flowing. When the plunger 22 is attracted to the core 26 by the magnetic flux, a force for urging the plunger 22 in the axial direction and a force for urging the plunger 22 in the radial direction are also generated. By the force biased in the radial direction, the portion where the plunger 22 is in contact with the upper end portion of the second intermediate portion 54 is inclined as a fulcrum, so that the rod portion 76 is in a state where the tip of the rod portion 76 is in contact with the opening 64. A gap is formed between the front end of each and the opening 64. The hydraulic fluid flows into the first liquid chamber 58 from the gap. By increasing the amount of current supplied to the coil 24, the angle of inclination of the axis of the plunger 22 with respect to the axis of the housing 20 is also increased, and the gap between the tip of the rod portion 76 and the opening 64 is increased. That is, in the electromagnetic linear valve 10, the hydraulic fluid is changed into the first liquid chamber by changing the inclination angle of the axis of the plunger 22 with respect to the axis of the housing 20 at the initial stage of the flow of the hydraulic fluid into the first liquid chamber 58. It is restrained from flowing into 58.

  However, if the inclination angle of the axis of the plunger 22 with respect to the axis of the housing 20 is increased, the magnetic resistance between the lower end surface of the core 26 and the upper end surface of the plunger 22 is increased, so that excessive inclination is not preferable. Therefore, in the electromagnetic linear valve 10, the flange portion 82 is formed at the upper end portion of the plunger 22, and when the inclination angle of the axis line of the plunger 22 with respect to the axis line of the housing 20 increases, the flange portion 82 serves as a connecting portion. The sleeve 32 is brought into contact with the sleeve 32. That is, excessive inclination of the plunger 22 is prohibited by the flange portion 82 as the protruding portion.

  Then, after the flange portion 82 of the plunger 22 abuts against the sleeve 32, when the amount of current supplied to the coil 24 is further increased, the tip of the plunger 22 moves away from the opening 64 of the through hole 62, and the plunger 22 moves in the separating direction. To do. That is, the plunger 22 is supported at two points in the housing 20 by the sleeve 32 and the upper end portion of the second intermediate portion 54 in a state where the distal end of the plunger 22 is separated from the opening 64, in other words, in a separated state. is there. As described above, the sleeve 32 which is one of the two support points is non-magnetic, and no magnetic contact is generated between the sleeve 32 and the flange portion 82. Therefore, in the electromagnetic linear valve 10, smooth movement in the axial direction is ensured with the plunger 22 in a separated state.

  Furthermore, the upper end portion of the second intermediate portion 54 that is another support point is in contact with the contact portion 74 of the plunger 22. The outer diameter of the contact portion 74 is smaller than the outer diameter of the second cylindrical portion 72 positioned above the contact portion 74, and the cross-sectional area is between the second cylindrical portion 72 of the plunger 22 and the contact portion 74. It is supposed to decrease rapidly. For this reason, magnetic saturation occurs in the contact portion 74, and the amount of magnetic flux flowing through the contact portion 74 is smaller than the amount of magnetic flux flowing through the second cylindrical portion 72. The amount of magnetic flux flowing in the contact portion between the plunger 22 and the inner peripheral surface of the housing 20 is largely related to the frictional force generated between the plunger 22 and the inner peripheral surface of the housing 20, and the amount of magnetic flux flowing in the contact portion. The frictional force decreases as the value decreases. Therefore, the frictional force generated between the upper end portion of the second intermediate portion 54 and the contact portion 74 of the plunger 22 is relatively small, and it is possible to further ensure the smooth movement of the plunger 22. Yes.

  In addition, if air bubbles enter the liquid chamber in which the plunger 22 is accommodated, that is, the first liquid chamber 58, the damping effect by the hydraulic fluid is reduced, and the self-excited vibration of the plunger is likely to occur. That is, bubbles in the first liquid chamber 58 are also considered as one of the factors that cause self-excited vibration. For this reason, it is desirable that the bubbles that have entered the first liquid chamber 58 are discharged to the low pressure side hydraulic fluid passage 14. However, it is difficult to discharge the upper end portion of the first liquid chamber 58, that is, the bubbles entering the first plunger liquid chamber 86 to the fourth plunger liquid chamber 92 that opens to the low-pressure side hydraulic fluid passage 14. is there. In particular, if it is a bubble that has entered the bottomed hole 100 for accommodating the compression coil spring 102, it is even more difficult to discharge. Therefore, in the electromagnetic linear valve 10, the through passage 104 is formed so as to extend in the radial direction from the inside of the bottomed hole 100, and the third plunger liquid chamber 90 and the fourth plunger liquid chamber 92 are communicated with each other. A notch 84 is formed as a passage. And the notch part 84 and the penetration path 104 are located in the mutually opposite side on both sides of the axis line of the plunger 22. FIG. Thereby, the inflow path of the hydraulic fluid from the fourth plunger liquid chamber 92 as the valve chamber into the bottomed hole 100 and the outflow path of the hydraulic fluid from the bottomed hole 100 to the fourth plunger liquid chamber 92 are established. It is possible to make them different, and it is possible to suitably discharge the bubbles in the bottomed hole 100 to the fourth plunger liquid chamber 92.

  Specifically, when the plunger 22 moves upward, the upper end portion of the plunger 22 enters the first plunger liquid chamber 86, whereby the volume of the first plunger liquid chamber 86 is reduced and the working fluid is transferred to the first plunger. The liquid flows out from the liquid chamber 86 to the fourth plunger liquid chamber 92. On the other hand, when the plunger 22 moves downward, the volume of the first plunger liquid chamber 86 increases, and the working fluid flows from the fourth plunger liquid chamber 92 into the first plunger liquid chamber 86. Therefore, when the plunger 22 moves downward, the hydraulic fluid in the fourth plunger liquid chamber 92 flows into the third plunger liquid chamber 90 as the plunger chamber via the notch 84, and further, the second plunger The liquid flows into the first plunger liquid chamber 86 through the liquid chamber 88. Due to the inflow of the working fluid into the first plunger liquid chamber 86, the bubbles that have entered the bottomed hole 100 are discharged to the second plunger liquid chamber 88 through the through passage 104. When the plunger 22 moves upward, bubbles in the second plunger liquid chamber 88 are discharged to the fourth plunger liquid chamber 92 due to the flow of hydraulic fluid from the first plunger liquid chamber 86 to the fourth plunger liquid chamber 92. It is done. Therefore, in the electromagnetic linear valve 10, the bubbles in the bottomed hole 100 can be discharged from the first liquid chamber 58, and the occurrence of self-excited vibration can be suppressed.

Modified example

  FIG. 3 shows an electromagnetic linear valve 110 obtained by modifying the electromagnetic linear valve 10. The electromagnetic linear valve 110 according to the modified example has substantially the same configuration as that of the electromagnetic linear valve 10 except for the plunger 112 and the housing 114. Therefore, the description will focus on them, and the components having the same functions will be described. The description will be omitted or simplified using the same reference numerals.

  The housing 114 included in the electromagnetic linear valve 110 according to the modification is configured by a covered cylindrical member 120 having a closed cylindrical shape and a valve member 30 fitted into the lower end portion of the covered cylindrical member 120. The covered cylindrical member 120 includes a columnar core portion 122 and a cylindrical portion 124, and is integrally formed from a single material made of a ferromagnetic material. However, the upper end portion of the cylindrical portion 124, that is, the portion continuing to the core portion 122 of the cylindrical portion 124 is demagnetized by laser processing, and the covered cylindrical member 120 includes the core portion 122 having ferromagnetism and the non-magnetic portion. An upper end portion (hereinafter sometimes referred to as “nonmagnetic cylindrical portion”) 126 of the magnetized cylindrical portion 124 and a portion having ferromagnetism (hereinafter referred to as “strong”) obtained by removing the nonmagnetic cylindrical portion 126 from the cylindrical portion 124. It is possible to classify it into 128. In FIG. 3, the boundary between the core portion 122 and the nonmagnetic cylindrical portion 126 and the boundary between the nonmagnetic cylindrical portion 126 and the ferromagnetic cylindrical portion 128 are indicated by dotted lines.

  The inside of the ferromagnetic cylindrical portion 128 has a stepped shape. The ferromagnetic cylindrical portion 128 has an upper end portion 130 positioned at the upper end portion, a lower end of the upper end portion 130, and an inner diameter smaller than the inner diameter of the upper end portion 130. The first intermediate part 132 is divided into a first intermediate part 132, a second intermediate part 134 having an inner diameter smaller than the inner diameter of the first intermediate part 132, and a lower end part 136 positioned at the lower end part. Can do. The valve member 30 is fixedly fitted into the lower end portion 136, and the housing 114 is partitioned into a first liquid chamber 138 and a second liquid chamber 140 by the valve member 30.

  The plunger 112 is made of a ferromagnetic material, and is disposed in the first liquid chamber 138 so as to be movable in the axial direction. The plunger 112 is positioned below the first cylindrical portion 150 having the largest outer diameter, the second cylindrical portion 152 having an outer diameter smaller than the outer diameter of the first cylindrical portion 150, and the first cylindrical portion 150. 2 located below the cylindrical portion 152 and having an outer diameter smaller than the outer diameter of the second cylindrical portion 152, and an outer diameter located below the contacting portion 154 and smaller than the outer diameter of the contact portion 154. The rod portion 156 has a stepped shape. A convex portion 158 is formed on the upper end surface of the first cylindrical portion 150.

  The first cylindrical portion 150 of the plunger 112 is provided so as to face the core portion 122 and is inserted into the upper end portion 130 of the ferromagnetic cylindrical portion 128, and the second cylindrical portion 152 is connected to the first intermediate portion 132. The contact portions 154 are inserted into the second intermediate portion 134, respectively. The plunger 112 has substantially the same shape except for the plunger 22 of the electromagnetic linear valve 10 and the flange portion 82, and has the same outer diameter. Further, the ferromagnetic cylindrical portion 128 of the housing 114 into which the plunger 112 is inserted has substantially the same shape as the wall member 28 of the electromagnetic linear valve 10 and has the same inner diameter. Therefore, also in the electromagnetic linear valve 110 of the modified example, the clearance between the plunger 112 and the ferromagnetic cylindrical portion 128 is the same as that of the upper end portion of the contact portion 154 and the minimum clearance portion, similarly to the electromagnetic linear valve 10. When the axis of the plunger 112 and the axis of the housing 114 are misaligned with each other, the plunger 112 and the ferromagnetic cylindrical portion 128 are separated from each other in the second intermediate portion. The upper end portion of 134 and the upper end portion of the contact portion 154 come into contact with each other. In FIG. 3, each clearance is exaggerated in order to clarify the difference in clearance.

  A bottomed hole 160 is formed in the upper end surface of the plunger 112, and the compression coil spring 102 and the stopper 106 are disposed in the bottomed hole 160. The plunger 112 is formed with two through passages 162 and 164 extending in the radial direction from the inside of the bottomed hole 160, and the two through passages 162 and 164 extend in directions opposite to each other. I'm out. That is, the two through passages 162 and 164 are formed at two equally spaced positions in the circumferential direction. Further, on the outer peripheral surface of the contact portion 154 of the plunger 112, only two notches (only one notch 166 is shown in FIG. 3) so as to extend in the axial direction at two equally spaced positions in the circumferential direction. ) Is formed, and the third plunger liquid chamber 90 and the fourth plunger liquid chamber 92 are communicated with each other by a notch 166 serving as a communication path. The formation position of the notch portion 166 and the formation position of the through passages 162 and 164 are shifted by 90 ° in the circumferential direction, so that the notch portion 166 as the communication passage and the through passages 162 and 164 do not intersect each other. ing.

  With the above-described structure, in the electromagnetic linear valve 110 of the modified example, as in the electromagnetic linear valve 10 described above, the axis of the housing 114 is the axis of the plunger 112 at the initial stage of the working fluid flowing into the first liquid chamber 138. By changing the angle of inclination with respect to, the hydraulic fluid is prevented from flowing into the first liquid chamber 138 vigorously. Further, in the electromagnetic linear valve 110 of the modified example, when the plunger 112 is excessively inclined, the outer edge of the upper end surface of the first cylindrical portion 150, that is, between the first cylindrical portion 150 and the convex portion 158. The outer edge of the step surface is in contact with the non-magnetic cylindrical portion 126 as the connecting portion, and the smooth movement of the plunger 112 in the axial direction is ensured. Furthermore, also in the electromagnetic linear valve 110 of the modified example, the flow path of the hydraulic fluid from the fourth plunger liquid chamber 92 into the bottomed hole 160 and the bottomed hole are formed by the through passages 162 and 166 and the notch 166. It is possible to change the outflow path of the working fluid from the inside of the 160 to the fourth plunger liquid chamber 92, and it is possible to suitably discharge the bubbles in the bottomed hole 160 to the fourth plunger liquid chamber 92. It is said that.

  FIG. 4 shows another electromagnetic linear valve 170 which is another modification of the electromagnetic linear valve 10. Since the electromagnetic linear valve 170 of the modified example has substantially the same configuration as the electromagnetic linear valve 10 except for the plunger 172 and the housing 174, the description will focus on them, and the components having the same functions will be described. The description will be omitted or simplified using the same reference numerals.

  A housing 174 provided in the electromagnetic linear valve 170 of the modification has a covered cylindrical member 184 configured by a core portion 180 and a cylindrical portion 182 that constitutes a wall surface. The covered cylindrical member 184 is integrally formed from a single material made of a ferromagnetic material, but the upper end portion of the cylindrical portion 182, that is, the portion continuing to the core portion 180 of the cylindrical portion 182 is formed by laser processing. In FIG. 3, the nonmagnetic cylindrical portion 186 that is a part thereof is clarified by a dotted line in FIG. Note that portions other than the nonmagnetic cylindrical portion 186 of the cylindrical portion 182 have ferromagnetism and may be referred to as a ferromagnetic cylindrical portion 188.

  The inner diameter of the ferromagnetic cylindrical portion 188 of the covered cylindrical member 184 is made uniform, and the plunger 172 having a generally cylindrical plunger body 190 made of a ferromagnetic material is formed in the ferromagnetic cylindrical portion 188 having the uniform inner diameter. Has been inserted. That is, the ferromagnetic cylindrical portion 188 functions as a plunger body portion insertion portion. In the plunger main body 190 as the main body, an extending portion 192 extending in the radial direction is formed at the central portion in the axial direction thereof, and the outer diameter of the extending portion 192 is the outer diameter of the other portion. It is getting bigger. For this reason, the clearance between the plunger main body 190 and the cylindrical portion 182 is minimized at the extended portion 192 as the minimum clearance portion. Incidentally, the outer diameter of the extending portion 192 is slightly smaller than the inner diameter of the cylindrical portion 182 so that the plunger 172 can move smoothly in the axial direction in the housing 174. In FIG. 4, each clearance is exaggerated in order to clarify the difference in clearance.

  A bottomed hole 194 is formed in the lower end surface of the plunger main body 190, and a rod member 196 is fixedly fitted in the bottomed hole 194. The lower end of the rod member 196 faces the valve member 30 fitted to the lower end portion of the covered cylindrical member 184, and is seated in the opening 64 of the through hole 62 formed in the valve member 30. A bottomed hole 198 is also formed in the upper end surface of the plunger main body 190, and the compression coil spring 102 and the stopper 106 are disposed in the bottomed hole 198. A through passage 200 is formed in the plunger main body 190 so as to extend in the radial direction from the inside of the bottomed hole 198, and the through passage 200 opens on the outer peripheral surface of the plunger main body 190. Furthermore, two axial passages 202 and 204 are formed in the plunger main body 190 so as to extend in the axial direction thereof. One axial passage 202 opens to the upper end surface and the lower end surface of the plunger main body 190, and includes a first plunger chamber 206 defined by the core portion 180 and the plunger main body 190, the plunger main body 190, and the valve member. 30 communicates with the second plunger chamber 208 defined by the. On the other hand, another axial passage 204 opens to the lower end surface of the plunger main body 190 and the through passage 200, and communicates the second plunger chamber 208 and the inside of the through passage 200. An annular member 210 made of a nonmagnetic material is fixedly fitted around the lower end portion of the outer peripheral surface of the plunger main body 190.

  Due to the above-described structure, in the electromagnetic linear valve 170 of the modified example, as in the electromagnetic linear valve 10, the axis of the housing 174 is the axis of the plunger 172 at the initial stage of the flow of the hydraulic fluid into the first liquid chamber 138. By changing the angle of inclination with respect to, the hydraulic fluid is prevented from flowing into the first liquid chamber 138 vigorously. Further, in the electromagnetic linear valve 170 of the modified example, when the plunger 112 is excessively inclined, the outer edge of the upper end surface of the plunger main body 190, that is, the outer edge of the step surface between the plunger main body 190 and the convex portion 158. However, it is made to contact | abut to the nonmagnetic cylindrical part 186 as a connection part, and the movement to the smooth axial direction of the plunger 172 is ensured. Further, a nonmagnetic annular member 210 is provided at the lower end portion of the outer peripheral surface of the plunger main body 190. For this reason, even if the lower end portion of the plunger main body 190 comes into contact with the ferromagnetic cylindrical portion 188 when the plunger 172 is separated, magnetic contact does not occur between the lower end portion of the plunger main body 190 and the ferromagnetic cylindrical portion 188. Therefore, in this electromagnetic linear valve 170, the smooth movement in the axial direction is ensured by the annular member 210.

  Also in the electromagnetic linear valve 170 of the modified example, the flow path of the working fluid from the second plunger fluid chamber 208 as the valve chamber into the bottomed hole 198 is formed by the through passage 200 and the axial passages 202 and 204, The flow path of the hydraulic fluid from the inside of the bottomed hole 198 to the second plunger liquid chamber 208 can be made different, and the air bubbles in the bottomed hole 198 are suitably discharged to the second plunger liquid chamber 208. It is possible. More specifically, when the plunger 172 moves downward, the working fluid in the second plunger fluid chamber 208 flows into the first plunger fluid chamber 206 as the plunger chamber via the axial passage 202 as the communication passage. To do. When the plunger 172 moves upward, bubbles that have entered the bottomed hole 198 due to the flow of hydraulic fluid from the first plunger liquid chamber 206 to the second plunger liquid chamber 208 are passed through the through passage 200 and the axial passage. The liquid is discharged to the second plunger liquid chamber 208 through 204.

  Incidentally, in the electromagnetic linear valve 170 of the modified example, an extending portion 192 is formed on the outer peripheral surface of the plunger 172, and the extending portion 192 functions as a minimum clearance portion. It may be configured by two tapered surfaces, and the portion having the largest outer diameter may function as the minimum clearance portion. Specifically, as shown in FIG. 5, the first taper surface 222 is formed on the outer peripheral surface of the plunger 220 so that the outer diameter decreases from the center to the upper end, and the first taper is formed. The second tapered surface 224 is formed so that the outer diameter decreases from the lower end of the surface 222 toward the lower end portion of the plunger 220. That is, the portion where the first tapered surface 222 and the second tapered surface 224 intersect functions as the minimum clearance portion. Thus, the electromagnetic linear valve 226 provided with the plunger 220 formed with the two tapered surfaces 222 and 224 also exhibits the same effect as the electromagnetic linear valve 170 of the modification.

  10: Electromagnetic linear valve 20: Housing 22: Plunger 24: Coil 26: Core (core portion) 28: Wall member (plunger main body inserted portion) 30: Valve member (partition portion) 32: Sleeve (connecting portion) 52 : First intermediate part (large inner diameter part) 54: Second intermediate part (small inner diameter part) (minimum clearance part) 58: First liquid chamber 60: Second liquid chamber 62: Through hole 64: Opening 70: First column Portion (main body portion) 72: second cylindrical portion (main body portion) (large diameter portion) 74: contact portion (main body portion) (small diameter portion) 76: rod portion 82: flange portion (protruding portion) 84: notch portion (continuous) 90): Third plunger liquid chamber (plunger chamber) 92: Fourth plunger liquid chamber (valve chamber) 100: Bottomed hole 102: Compression coil spring (elastic body) 110: Electromagnetic linear valve 112: Plunger 114: Housing 122: Core portion 126: Non-magnetic cylindrical portion (connecting portion) 128: Ferromagnetic cylindrical portion (plunger main body inserted portion) 132: First intermediate portion (large inner diameter portion) 134: Second intermediate Part (small inner diameter part) (minimum clearance part) 138: first liquid chamber 140: second liquid chamber 150: first cylindrical part (main body part) 152: second cylindrical part (main body part) (large diameter part) 154: Contact portion (main body portion) (small diameter portion) 156: Rod portion 160: Bottomed hole 162: Through passage 164: Through passage 166: Notch portion (communication passage) 170: Electromagnetic linear valve 172: Plunger 174: Housing 180: Core 186: Non-magnetic cylindrical part (connecting part) 188: Ferromagnetic cylindrical part (plunger main body inserted portion) 190: Plunger main body (main body part) 192: Extension portion (minimum clearance portion) 198: Bottomed hole 200: Through passage 202: Axial passage (communication passage) 206: First plunger chamber (plunger chamber) 208: Second plunger chamber (valve chamber) 220: Plunger 226: Electromagnetic linear valve

Claims (10)

(a) a partition section in which the interior is partitioned into a first liquid chamber and a second liquid chamber, and a through-hole is formed so as to pass through the first liquid chamber and the second liquid chamber; a housing having an outflow port in communication with the first liquid chamber; and (c) an inflow port in communication with the second liquid chamber and filled with a working fluid;
(A) A main body formed of a ferromagnetic material, and (B) a rod having an outer diameter smaller than the outer diameter of the main body, extending from one end of the main body, and the tip functioning as a valve body The tip of the rod portion closes the opening to the first liquid chamber of the through hole that functions as a valve seat with the movement in the axial direction. A plunger disposed in the first liquid chamber,
An elastic body that urges the plunger in one of a direction in which the distal end portion of the rod portion approaches the opening of the through hole and a direction away 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 housing comprises:
It is formed of a ferromagnetic material, and has a plunger main body insertion portion into which the main body portion of the plunger is inserted with a clearance,
One of the plunger body portion and the plunger body portion insertion portion,
Together positioned between the one end and the other end of the body portion in the axial direction of the plunger, it has a clearance smallest minimum clearance portion between the said main body portion plunger body portion insertion member,
The inner peripheral surface of the inserted portion of the plunger main body portion has two tapered surfaces whose inner diameter increases from a certain portion toward both ends, or the outer peripheral surface of the main body portion has a certain portion. An electromagnetic linear valve in which a certain portion functions as the minimum clearance portion by forming two tapered surfaces such that the outer diameter decreases from both ends toward the both ends . The electromagnetic linear valve
The plunger in a state where one of the plunger main body portion and the plunger main body insertion portion of the housing is in contact with the other in the minimum clearance portion, and the tip of the rod portion is seated in the opening. The electromagnetic linear valve according to claim 1, wherein the valve opening amount increases with an increase in an inclination angle of the axis of the housing relative to the axis of the housing. The housing comprises:
(a) a core portion made of a ferromagnetic material and facing an end surface on the other end side of the main body portion of the plunger; and (b) the core portion and the plunger main body portion insertion portion. And a connecting portion that connects in a state where no magnetic flux flows between them,
3. The electromagnetic linear valve according to claim 2, wherein a part of the plunger facing the connecting portion is configured to contact the connecting portion by increasing the inclination angle. The connecting portion is
The core portion is formed of a non-magnetic material and is externally fitted to the core portion and the plunger body portion insertion portion, and the end surface of the core portion and the end surface of the plunger body portion insertion portion are separated from each other. And a member connecting the plunger body portion insertion portion,
The plunger has a protruding portion formed on the outer peripheral surface of the other end portion of the main body portion, and the protruding portion is located between the end surface of the core portion and the end surface of the plunger main body portion insertion portion. The electromagnetic linear valve according to claim 3, wherein the electromagnetic linear valve is configured to come into contact with the connecting portion as the inclination angle increases. The main body portion of the plunger is (a) a small diameter portion that is located on the rod portion side and is formed of a ferromagnetic material, and (b) a side opposite to the rod portion side that is continuous with the small diameter portion. And is composed of a large diameter portion formed of a ferromagnetic material,
The plunger main body insertion portion of the housing includes (a) a small inner diameter portion in which the small diameter portion is inserted and formed of a ferromagnetic material, and (b) continuous with the small inner diameter portion. The inner diameter is larger than the inner diameter, the large diameter portion is inserted, and consists of a large inner diameter portion formed of a ferromagnetic material,
5. The electromagnetic linear valve according to claim 1, wherein one of the small-diameter portion and the small-diameter portion has the minimum clearance portion.   The inner peripheral surface of the plunger main body insertion portion has two tapered surfaces whose inner diameter increases from a certain portion toward both ends, so that the certain portion functions as the minimum clearance portion. The electromagnetic linear valve according to any one of claims 1 to 5.   The outer peripheral surface of the main body portion is formed into two tapered surfaces such that the outer diameter decreases from a certain portion toward both ends, and the certain portion functions as the minimum clearance portion. The electromagnetic linear valve according to claim 5. The housing comprises:
Formed of a ferromagnetic material, and having a core portion facing the end surface on the other end side of the main body portion of the plunger;
The main body is
A bottomed hole formed on the end surface on the other end side and opening toward the core, and a through passage opening in the bottomed hole and on the outer peripheral surface of the main body,
The elastic body is
A compression coil spring that is disposed in the bottomed hole in a compressed state by the bottom of the bottomed hole and the core, and biases the plunger in a direction in which the tip of the rod portion approaches the opening. The electromagnetic linear valve according to any one of claims 1 to 7. The first liquid chamber is
(a) a valve chamber defined by an end surface of the plunger on one end portion side and the partition portion of the housing, and present around the rod portion and communicating with the outflow port; b) including a plunger chamber positioned on the other end side of the main body from the valve chamber,
The plunger has a communication passage communicating the valve chamber and the plunger chamber;
The electromagnetic linear valve according to claim 8, wherein the electromagnetic linear valve is configured such that the through path and the communication path do not intersect.   The electromagnetic linear valve according to claim 9, wherein the valve chamber and the plunger chamber are located with the minimum clearance portion interposed therebetween.

Images