JPH10220624A - Solenoid valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solenoid valve which stably controls pressure or flow and produces good control characteristics even if gas such as air is mixed in operating fluid. SOLUTION: A bearing member 16 for slidably guiding a plunger 6 in the axial direction is provided on the inner periphery of a solenoid 3, a cylindrical valve part 64 slidably inserted into a flow-in passage 8 of a port 4 is provided on the tip end of the plunger 6, and an opening 65 gradually opened by a movement of the plunger 6 in the axial direction is provided in the side wall of the cylindrical valve 64. An upper end surface of the bearing 16 is made to be a regulation surface for regulating the position of the plunger 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solenoid valve used for, for example, hydraulic control and flow rate control.

[0002]

2. Description of the Related Art A conventional solenoid valve of this type is known, for example, as shown in FIG.

That is, a center post 100, a solenoid 101 provided so as to surround the center post 100, a port portion 102 provided at a predetermined distance from the center post 101 in the axial direction, and a solenoid 101
A plunger 104 is movably inserted in the axial direction into a plunger chamber 103 formed by the inner peripheral surface of the plunger and the opposing surfaces of the center post 100 and the port portion 102, and is inserted between the plunger 104 and the center post 100. A spring 105 is provided to press the plunger 104 against the port portion 102, and an inflow passage 106 and an outflow passage 107 provided in the port portion 102 are provided.

The solenoid 101 is excited to attract the plunger 104 to the center post 100 against the spring force of the spring 105, thereby opening the inflow passage 106 and changing the amount of current supplied to the solenoid 101 to change the inflow passage. The control pressure is controlled by controlling the opening amount of 106.

[0005]

However, in the case of the prior art described above, if air is mixed in the working liquid such as hydraulic pressure, the control pressure is reduced as shown in a section of FIG. There was a problem of instability.

[0006] This is because the conventional plunger 104 is configured to come into contact with and separate from the port portion 102 in a planar manner, and as shown in FIG. (Valve sensitivity) is large, and even if the plunger 104 moves slightly, it has been found that the cause is that the control pressure changes sensitively.

Although the conventional plunger 104 is supported on the inner periphery of the bobbin 108 of the solenoid 101, the minimum clearance is 60 to 8 due to the difference in the coefficient of thermal expansion between the two.
0 [μm] is the limit, and therefore, chattering in the circumferential direction is apt to occur, and the center of the port portion 102 with respect to the inflow path 106 is also likely to occur.

As a method for solving these problems, there is a method of providing air bleeding inside the solenoid.
When the solenoid valve is inside the hydraulic unit (such as when applied to an automatic transmission, etc.) or when the hydraulic unit itself is mixed with air oil, air bleeding has not been enough.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art.
It is an object of the present invention to provide a solenoid valve which is stable in pressure and flow rate even when gas such as air is mixed in a working liquid and has excellent control characteristics.

[0010]

In order to achieve the above object, according to the present invention, there is provided a center post, a solenoid provided so as to surround the center post, and a predetermined distance in the axial direction from the center post. A plunger movably inserted in the axial direction into a plunger chamber formed by a port portion provided at a distance, an inner peripheral surface of the solenoid, and an opposing surface of the center post and the port portion; A spring inserted between the springs to press the plunger against the port, and an inflow passage provided in the port, wherein the solenoid is excited to move the plunger toward the center post against the spring force of the spring. The amount of opening of the inflow passage at the side of the plunger chamber is changed by changing the amount of electricity supplied to the solenoid to change the suction force. In Gosuru solenoid valve,
A bearing member for guiding the plunger slidably in the axial direction is provided on the inner periphery of the solenoid, and a cylindrical valve portion is slidably inserted into the inner periphery of the inflow passage of the port portion at the tip of the plunger. An opening is provided on the side wall of the cylindrical valve portion, the opening being gradually opened by the axial movement of the plunger.

In the present invention, the opening in the side wall of the cylindrical valve portion gradually opens in accordance with the stroke of the plunger, but the increment of the opening area per unit stroke is small, and the change in control pressure and flow rate is also small. . Therefore, even if the air or the like in the control liquid is compressed by the gas and the plunger is further stroked, the increase in the opening area is small, the axial chattering can be prevented, and the change in the control pressure and flow rate characteristics can be suppressed to a small value. .

Further, since the plunger is supported by the bearing member, the plunger can be prevented from rattling in the radial direction, and chattering in the radial direction can be prevented.

Further, the bearing member is provided with a fitting cylindrical portion fitted and fixed to the inner periphery of the inflow passage of the port portion, and a gap is provided between the outer periphery of the bearing member and the inner periphery of the solenoid. This gap serves as a flow path for flowing the fluid flowing from the inflow path to the back side of the plunger. With this configuration, since the bearing member is positioned with respect to the inflow passage of the port portion, the center axis of the cylindrical valve portion of the plunger guided by the bearing member can also be accurately centered with respect to the inflow passage. it can.

The bearing member may be provided with a regulating surface that regulates the position of the plunger when the plunger is urged toward the port portion by the spring force of the spring, and does not face the fluid flow path.

Therefore, the position of the plunger is regulated on a surface that does not face the fluid flow path (a surface on which dirt or the like in the fluid does not adhere), so that the plunger is properly regulated.

Also, a center post, a solenoid provided to surround the center post, a port portion provided at a predetermined interval in the axial direction from the center post, an inner peripheral surface of the solenoid, a center post and a port. A plunger movably inserted in an axial direction into a plunger chamber formed by an opposing surface of the portion, a spring inserted between the plunger and the center post to press the plunger against a port portion, and the port And an inflow path provided in the section, and excites the solenoid to attract the plunger to the center post side against the spring force of the spring, thereby changing the amount of electricity supplied to the solenoid to change the attraction force. In a solenoid valve for controlling an opening amount of an outlet of the inflow passage on the plunger chamber side, At the end, a cylindrical valve portion slidably inserted into the inner periphery of the inflow passage of the port portion is protruded, and an opening portion gradually opened by the axial movement of the plunger is provided on a side wall of the cylindrical valve portion. A cylindrical valve sleeve for supporting the cylindrical valve portion may be provided.

Therefore, the opening of the side wall of the cylindrical valve portion gradually opens in accordance with the stroke of the plunger, so that the increment of the opening area per unit stroke is small, and the change in the control pressure and the flow rate is also small. Therefore, even if the air or the like in the control liquid is compressed by the gas and the plunger is further stroked, the increase in the opening area is small, the axial chattering can be prevented, and the change in the control pressure and flow rate characteristics can be suppressed to a small value. .

Further, since the cylindrical valve portion is supported by the valve sleeve, the plunger can be restrained from rattling in the radial direction, chattering in the radial direction can be prevented, and the valve sleeve has a cylindrical shape. Therefore, insert molding is also possible.

Further, a center post, a solenoid provided so as to surround the center post, a plunger attracted by excitation of the solenoid, a valve which moves in accordance with the movement of the plunger, and a valve which moves the valve to the plunger side A spring for pressing and a port portion having an inflow path are provided, and the solenoid is excited to attract the plunger to the center post side against the spring force of the spring, and to vary the amount of electricity supplied to the solenoid to attract the solenoid. In a solenoid valve for controlling an opening amount of an outlet on the valve side of the inflow passage by changing a force, a cylindrical valve portion slidably inserted into an inner periphery of an inflow passage of a port portion at a tip end of the valve. It is also possible to provide an opening which is gradually opened by the axial movement of the plunger on the side wall of the cylindrical valve portion.

Therefore, the opening of the side wall of the cylindrical valve portion is gradually opened in accordance with the stroke of the plunger, so that the increment of the opening area per unit stroke is small, and the control pressure and the flow rate are small. Therefore, even if the air or the like in the control liquid is compressed by the gas and the plunger is further stroked, the increase in the opening area is small, the axial chattering can be prevented, and the change in the control pressure and flow rate characteristics can be suppressed to a small value. .

[0021]

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) FIG. 1 shows a first embodiment of the present invention.
2 shows a solenoid valve according to the embodiment.

That is, the solenoid valve 1 includes a center post 2, a solenoid 3 provided to surround the center post 2, and a port portion 4 provided at a predetermined distance from the center post 2 in the axial direction. Have.

A hollow plunger chamber 5 is formed by the inner peripheral surface of the solenoid 3 and the opposing surfaces of the center post 2 and the port 4, and a plunger 6 is formed in the plunger chamber 5.
Are movably inserted in the axial direction. A spring 7 is mounted between the plunger 6 and the center post 2,
The plunger 6 is pressed against the port 4 by the spring force of the spring 7.

The port portion 4 is provided with an inflow channel 8 penetrating in the axial direction, the center post 2 is provided with a first outflow channel 9, and a second outflow channel 10 is provided at the base of the port portion 4. Is provided.

The center post 2 is provided with a through hole 21 penetrating in the center axis direction.
The adjusting screw 22 for adjusting the set load is screwed in, and the first outflow passage 9 is formed in the adjusting screw 22. One end of the spring 7 is engaged with an end of the adjusting screw portion 22 facing the plunger chamber 5.

The end face of the center post 2 facing the plunger chamber 5 is a tapered surface that gradually projects from the inner diameter end toward the outer diameter end toward the plunger chamber, and forms a cylindrical portion of the lower plate 11 forming a magnetic path. It faces the tip of 11a at a predetermined interval in the axial direction.

The solenoid 3 has a structure in which a coil 32 is wound around a bobbin 31. The center post 2 is fitted on the inner periphery of the upper half of the bobbin 31, the lower half is a plunger chamber 5, and the port 4 is a solenoid. 3 is provided so as to close the lower end opening. The lower plate 11 is in contact with the lower end surface of the solenoid 3. The lower plate 11 has a cylindrical shape with a flange, the flange portion 11b abuts on the lower end surface of the solenoid 3, and the cylindrical portion 11a is a bobbin 31 of the solenoid 3.
It is embedded in the inner circumference. The inner periphery of the cylindrical portion 11a of the lower plate 11 is covered with a thin resin portion 4a. Bobbin 31, thin resin portion 4a and port portion 4
Are integrally formed with the lower plate 11 inserted. The upper end of the center post 2 projects further upward from the upper end of the solenoid 3, and the inner end of an annular upper plate 12 serving as a yoke forming a magnetic path is fixed to the upper end of the center post 2.

A connector 13 is interposed between the upper plate 12 and the solenoid 3. This connector part 1
A socket 14 provided with a terminal 14 a is connected to 3, and a lead wire (not shown) extending from the solenoid 3 is embedded in the connector 13.

The solenoid 3 is housed in a case 15,
The outer diameter end of the upper plate 12 is fitted and fixed to the upper end opening of the case 15, and the outer diameter end of the flange 11 b of the lower plate 11 is fitted and fixed to the lower end opening of the case 15. As a result, the magnetic circuit H when the solenoid 3 is excited includes the center post 2, the plunger 6, the lower plate 1
1, it is formed so as to return to the center post 2 through the case 15 and the upper plate 12.

A stepped cylindrical sleeve 16 as a bearing member for guiding the plunger 6 slidably in the axial direction is provided on the inner periphery of the solenoid 3. The sleeve 16 is made of a non-magnetic material. The sleeve 161 is disposed on the inner periphery of the lower half of the plunger chamber 5 via a predetermined gap g. And a fitting cylinder portion 162 fitted to the inner periphery of the inflow path 8 of the bearing 4, and a communication hole 163 is provided at a lower end portion of the bearing portion 161.

The plunger 6 is located above the upper end of the bearing part 161 of the sleeve 16, has a diameter larger than the inner diameter of the bearing part 161, is smaller than the inner diameter of the solenoid 3, and has a predetermined distance between the inner circumference of the solenoid 3. Large diameter portion 6 forming gap G
1 and the bearing portion 161 extending downward from the lower end of the large diameter portion 61.
A sliding portion 62 slidably in contact with the inner periphery; a small-diameter portion 63 having a smaller diameter than the sliding portion 62 and extending further downward from the lower end of the sliding portion 62 to face a communication hole 163 opening at a lower portion of the bearing portion 161; And a cylindrical valve portion 64 extending further downward from the lower end of the portion 63 and slidably inserted into the inner periphery of the inflow passage 8 of the port portion 4. Hole 6 as opening
5 are provided.

An opening hole 65 of the cylindrical valve portion 64 is a circular hole, and a plurality of holes are provided in the circumferential direction. When no current is supplied, the upper end of the opening hole 65 and the upper end position of the cylindrical valve portion 64 are positioned. An overlap portion 66 is provided between the sleeve 16 and the sleeve 16 so as to be in close contact with the inner periphery of the fitting tube portion 162 and close the opening 65. If the overlap portion 66 is too large, the stroke until opening becomes longer, and even if the current is increased, the control pressure does not easily decrease. When the overlap portion 66 starts to decrease, the control pressure suddenly decreases, and the proportionality with the current is lost. It is desirable to make the size as small as possible as long as the sealing property can be secured.

The shape of the opening 65 is not limited to a round hole, and the shape can be selected according to required control pressure and flow characteristics. For example, a slit that opens to the tip of the cylindrical valve portion is provided. Alternatively, as shown in FIG. 2, it is also possible to form a shape (a) in which the centers of circles having different diameters are shifted from each other or a triangle (b).

The port portion 4 has an insertion tube portion 41 projecting below the lower end surface of the solenoid 3, and the inflow passage 8 is formed through the insertion tube portion 41. A seal member 42 such as an O-ring for sealing a fitting portion with the mounting hole 30 is mounted on the outer periphery of the insertion tube portion 41. A retaining ring 43 is attached to the outer periphery of the lower end of the fitting tube portion 162 of the sleeve 16 fitted to the inner periphery of the insertion tube portion 41 to prevent the sleeve 16 from coming off to the plunger chamber 5 side. The retaining ring 43 is formed integrally with the port portion 4, and the lower end of the fitting tubular portion 162 of the sleeve 16 is fixed by caulking.

FIG. 3 shows an example of a hydraulic circuit in which the solenoid valve of the present embodiment is used.

That is, the insertion tube portion 41 of the solenoid valve 1 is inserted and fixed in the mounting hole 30 of the hydraulic unit, and the inflow passage 8 communicates with the control chamber 301. Control room 3
01 is acts source pressure P _O from a hydraulic source (not shown) through a first orifice 302 is controlled by the predetermined pressure by the solenoid valve 1, the control pressure P _C is a second orifice 3
03, and is supplied to the spool valve 304 and the like. The first and second outflow passages 9 and 10 of the solenoid valve 1 are used as drain ports.

In the present invention, when the solenoid 3 is energized, the plunger 6 is attracted, and the plunger 6 moves toward the center post 2 as the current increases. An opening hole 65 in the side wall of the portion 64 is open. As shown in FIG.
Compared with the conventional planar opening / closing mechanism, the increment of the opening area per unit stroke is small, and the change in control pressure (valve sensitivity) is also small. Therefore, even if a gas having a compressibility such as air in the control liquid is compressed and the plunger 6 strokes extra, the increment of the opening amount is small, and FIG.
As shown in (1), the change in the control pressure can be suppressed small, and since the plunger 6 is supported by the sleeve 16, the rattling of the plunger 6 in the radial direction can be suppressed and chattering can be prevented. Can be.

In particular, the sleeve 16 is provided with a fitting cylindrical portion 162 fitted and fixed to the inner periphery of the inflow passage 8 of the port portion 4 and a gap G is provided between the outer periphery of the bearing portion 161 and the inner periphery of the solenoid 3. The bearing part 161 is positioned with respect to the inflow path 8,
The center axis of the cylindrical valve portion 64 of the plunger 6 guided by the sleeve 16 is also accurately centered with respect to the inflow path 8.

In the circuit shown in FIG. 3, the case where the solenoid valve 1 is used for hydraulic pressure control has been described, but the flow rate can be controlled. Further, although the first and second outflow passages 9 and 10 are used as drain ports, a configuration in which the control pressure is supplied from the first or second outflow passage may be adopted.

Next, the position regulation of the plunger 6 when the plunger 6 is urged toward the port portion 4 by the spring force of the spring 7 when the solenoid 3 is not excited will be described with reference to FIG. . FIG. 4 shows the plunger 6
In the enlarged view of the vicinity, two ways of position regulation are shown, separated on the left and right with the center line as a boundary.

The position of the plunger 6 can be regulated in two ways as shown in FIG.

That is, as shown on the left side (A side) of the center line in the figure, the upper end surface 162a of the fitting cylindrical portion 162 which is a step at the lower end of the bearing portion 161 is provided with a regulating surface for regulating the position of the plunger 6. And a case where the upper end surface 161a of the bearing portion 161 is a regulating surface for regulating the position of the plunger 6, as shown on the right side (B side) of the center line in the drawing.

As shown in the figure, in the case of the configuration like the side A, a clearance is provided between the upper end surface 161a of the bearing part 161 and the plunger 6, and the configuration like the side B is adopted. In such a case, it is necessary to provide a clearance between the upper end surface 162a of the fitting cylinder 162 and the plunger 6. In order to regulate the position of both parts without providing a clearance, the accuracy of dimensions and the like must be increased.In addition, due to the accuracy error or wear of individual parts, the position must be regulated only in one of them. This becomes unstable and may adversely affect the flow rate characteristics.

First, in the case of a configuration like the side A,
The position from the position where the plunger 6 is regulated (the solenoid 3 is not excited) to the time when the solenoid 3 is excited and the opening hole 65 is opened (the time until the opening is opened by a predetermined exciting force) is defined by the overlap portion 66. It is excellent in that it is determined only by the stroke. However, the upper end surface 1 of the fitting cylindrical portion 162
62a faces the flow path of a fluid such as oil when the opening hole 65 is opened, so that iron powder and dust (so-called contaminants) adhere and adsorb on the upper end surface 162a, and the opening hole 65 is completely closed. It is conceivable that an unclosed state may occur and the flow rate becomes unstable.

On the other hand, in the case of the configuration on the B side, from the position where the position of the plunger 6 is restricted (the solenoid 3 is not excited) until the solenoid 3 is excited and the opening hole 65 is opened. (Time until opening by a predetermined exciting force) is disadvantageous in comparison with the above-described configuration on the A side in that the position is determined by the mutual dimensions of the plunger 6 and the sleeve 16. However, in the case of the configuration on the B side, since the upper end surface 161a of the bearing portion 161 is located at a position not facing the fluid flow path, it is almost impossible for iron powder or dust to adhere or adsorb. Not
Further, by providing a sufficient clearance between the upper end surface 162a and the plunger 6, the opening hole 65 can be properly closed even if dust or the like adheres or adheres to the upper end surface 162a, and the flow rate is stabilized.

In view of the above, it is desirable to adopt a configuration such as that on the B side, so that the flow rate can be stabilized and the quality can be improved without affecting the control characteristics. In the above-described embodiment, the upper end surface 161a of the bearing portion 161 is defined as the regulating surface due to the relationship between the shapes of the plunger 6 and the sleeve 16, but the point is that if the upper surface 161a does not face the fluid flow path, It goes without saying that not only this surface but also an appropriate surface can be set as the regulating surface according to the shapes of the plunger and the sleeve.

(Second Embodiment) FIG. 5 shows a second embodiment of the present invention. In the first embodiment, the bearing member is provided to support the plunger. However, in the present embodiment, the length of the cylindrical valve portion is increased, and the cylindrical valve portion is provided by the cylindrical valve sleeve. Is supported to support the plunger. Other configurations and the like are the same as those of the first embodiment.
The same components are denoted by the same reference numerals, and description thereof will be omitted.

Hereinafter, a configuration different from the first embodiment will be described in detail with reference to FIG. FIG. 5 is a schematic configuration sectional view of a solenoid valve according to a second embodiment of the present invention.

As shown in the figure, in this embodiment, the length of the cylindrical valve portion 64A of the plunger 6A is increased, and the cylindrical valve sleeve 16A is positioned at the position of the cylindrical valve portion 64A. It is configured to be supported (bearing) by.

By making the length of the cylindrical valve portion 64A sufficiently long, the inclination of the plunger 6A is prevented.

By adopting such a configuration, unlike the first embodiment, the valve sleeve 16A can be formed in a cylindrical shape.
The valve sleeve 1
Since 6A can be fixed by insert molding, manufacture becomes easy.

The large diameter portion 61A of the plunger 6A
Gap G so that there is no contact between
Is provided, the plunger 6A is positioned with respect to the inflow path 8, and the center axis of the cylindrical valve portion 64A of the plunger 6A guided by the sleeve 16A is also accurately centered with respect to the inflow path 8.

With the above configuration, the same effects as those of the above-described first embodiment can be obtained, and the manufacturing can be facilitated.

(Third Embodiment) FIG. 6 shows a third embodiment of the present invention. In the above embodiment, the plunger is provided integrally with the cylindrical valve portion, but in the present embodiment, the plunger and the cylindrical valve member are formed as separate components. Since other configurations and the like are the same as those of the above-described embodiment, the same components are denoted by the same reference numerals and description thereof will be omitted.

Hereinafter, a configuration different from that of the first embodiment will be described in detail with reference to FIG. FIG. 6 is a schematic cross-sectional view of a main part of a solenoid valve according to a third embodiment of the present invention.

As shown in the figure, in the present embodiment, the plunger 6B and the cylindrical valve member 64B are separate parts.

The plunger 6B is connected to the plunger 6B.
The large diameter portion 61B is supported by the inner periphery of the bobbin 31B, and the cylindrical valve member 64B is supported by the valve sleeve 16B.

The valve sleeve 16B can be fixed by integral molding.

The cylindrical valve member 64B is pressed toward the plunger 6B by the oil pressure of the oil flowing from the inflow passage 8, and moves together with the plunger 6B.

With the above configuration, when the plunger and the cylindrical valve portion are integrated as in the above embodiment, the clearance of the valve portion is set to a fixed value (for example, It is necessary to strictly control the dimensional accuracy of the plunger, the valve sleeve, and the like in order to reduce the size to 60 μm or less. In the present embodiment, however, since the plunger and the cylindrical valve member are provided separately, the dimensions of each member are reduced. The management is relatively rough and the manufacturability is excellent.

Further, since the valve sleeve 16B can be fixed by integral molding, the number of steps is small and the workability is excellent.

Further, since the outer periphery of the plunger 6B also serves as a sliding portion with the magnetic path, it is different from the case where the bearing member covers a part of the outer peripheral region of the plunger as in the first embodiment. As a result, the magnetic attraction area can be ensured, so that the attraction force is improved and the size can be reduced.

(Fourth Embodiment) FIG. 7 shows a fourth embodiment of the present invention. In the above embodiment, the configuration applied to the so-called normally closed type solenoid valve is shown. In the present embodiment, the configuration applied to the so-called normally open type solenoid valve is shown. Since other configurations and the like are the same as those of the above-described embodiment, the same components are denoted by the same reference numerals and description thereof will be omitted.

In the above-described embodiment, the case of the normally closed type (the type which is closed when the current is OFF and the plunger moves and opens by energizing the solenoid when the current is turned ON) has been described as a normally open type. Type (open when current is off,
A type in which the plunger moves and closes when the solenoid is excited when the current is turned on can be applied. One embodiment will be described below with reference to FIG.

FIG. 7 is a schematic sectional view of a solenoid valve according to a fourth embodiment of the present invention.

As shown in the figure, unlike the above embodiment, a center post 2C is provided on the port 4 side.

The plunger 6C supported by the sleeve 16C is urged toward the port 4 by the spring 71C to press the valve member 641C, and the valve member 641C is pressed by the spring 72C.
Is pressed.

Here, the biasing force of the spring 71C can be adjusted by the adjusting screw 22C.

The end of the valve member 641C has an opening 6
A cylindrical valve portion 642C having a protrusion 5 is protrudingly provided, and is slidably disposed on the inner periphery of the inflow passage 8.

The valve member 641C is supported by the center post 2C by the bearing 161C.

With such a configuration, when the current is OFF, the valve member 641C is urged toward the plunger 6C by the spring 72C, and the opening hole 65 is opened.

[0073] Therefore, the control pressure P _C is the lowest pressure.

When the solenoid is excited by turning on the current, the plunger 6C is attracted by the center post 2C and the spring 7 is increased as the current value increases.
It moves against the urging force of 2C, and the opening 65 gradually closes.

[0075] Therefore, the control pressure P _C is gradually increased.

Incidentally, reference numeral 14C in the figure denotes a bracket for fixing to a predetermined portion.

As described above, similarly to the above-described normally closed type solenoid valve, as shown in FIG. The increment of the opening area with respect to the stroke is small, and the change of the control pressure (valve sensitivity) is also small. Therefore, even if a gas having a compressibility such as air in the control liquid is compressed and the plunger 6 is further stroked, the increment of the opening amount is small, and FIG.
As shown in (f), the change in the control pressure can be suppressed small, and the control characteristics are improved.

[0078]

As described above, according to the present invention, the opening of the side wall of the cylindrical valve portion is opened in accordance with the stroke of the plunger. And changes in flow rate are small. Therefore, even if the air in the control liquid is compressed and the plunger is further stroked, the increment of the opening area is small, and changes in the control pressure and the flow rate characteristics can be suppressed to be small, and the control characteristics are excellent.

Further, since the plunger is supported by the bearing member, rattling is suppressed, so that chattering can be prevented.

Further, the bearing member is provided with a fitting cylindrical portion which is fitted and fixed to the inner periphery of the inflow passage of the port portion, and if a gap is provided between the outer periphery of the bearing member and the inner periphery of the solenoid, the bearing member can receive the inflow of the port portion. Positioned relative to the road. The center axis of the cylindrical valve portion of the plunger guided by the bearing member can also be accurately centered with respect to the inflow path.

Further, by regulating the position of the plunger by a regulating surface provided on the bearing member so as not to obstruct the flow path of the fluid, the flow rate can be stabilized, and the control characteristics can be further improved.

Further, if the cylindrical valve portion is supported by a cylindrical valve sleeve, the plunger can be prevented from rattling in the radial direction, and chattering in the radial direction can be prevented. Molding is also possible, and manufacturability is improved.

[Brief description of the drawings]

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

FIG. 2 is a diagram showing an example of an opening hole applied to the solenoid valve according to the embodiment of the present invention.

FIG. 3 is a diagram showing an example of a hydraulic circuit in which the solenoid valve of the present invention is used.

FIG. 4 is an enlarged view of a main part of FIG. 1, showing two ways of position regulation divided into right and left with a center line as a boundary.

FIG. 5 is a schematic sectional view of a solenoid valve according to a second embodiment of the present invention.

FIG. 6 is a schematic configuration sectional view of a main part of a solenoid valve according to a third embodiment of the present invention.

FIG. 7 is a schematic configuration sectional view of a solenoid valve according to a fourth embodiment of the present invention.

FIG. 8 is a longitudinal sectional view of a conventional solenoid valve.

9 (a) is a graph showing control characteristics of a conventional solenoid valve, FIG. 9 (b) is a graph showing valve sensitivity of a conventional solenoid valve, and FIGS. 9 (c) and (e) are the present invention. And (d) and (f) are graphs showing the control characteristics of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Solenoid valve 2 Center post 21 Through hole 22 Adjustment screw part 3 Solenoid 31 Bobbin 32 Coil part 4 Port part 4a Thin resin part 41 Insertion cylinder part 42 Seal member 43 Retaining ring 5 Plunger chamber 6 Plunger 61 Large diameter part 62 Slide part 63 Small-diameter portion 64 Cylindrical valve portion 65 Opening hole 66 Overlap portion 7 Spring 8 Inflow channel 9, 10 First and second outflow channels 11a Cylindrical portion 11b Flange portion 11 Lower plate 12 Upper plate 13 Resin molded portion 14a Terminal 14 Socket Part 15 Case 16 Sleeve (bearing member) 161 Bearing part 161a Upper end face (of bearing part 161) 162 Fitting cylinder part 162a Upper end face (of fitting cylinder part 162) 163 Communication hole G Gap 30 Mounting hole 301 Control chamber 302, 303 first and second orifices Scan

Claims (5)

[Claims] 1. A center post, a solenoid provided to surround the center post, a port portion provided at a predetermined interval in the axial direction from the center post, an inner peripheral surface of the solenoid, a center post and a port. A plunger movably inserted in an axial direction into a plunger chamber formed by an opposing surface of the portion, a spring inserted between the plunger and the center post to press the plunger against a port portion, and the port And an inflow passage provided in the section, by energizing the solenoid to attract the plunger to the center post side against the spring force of the spring, and changing the amount of electricity to the solenoid to change the attraction force In a solenoid valve for controlling an opening amount of an outlet of the inflow passage on the plunger chamber side, an inner periphery of the solenoid is provided. In addition to providing a bearing member for guiding the lancer slidably in the axial direction, a cylindrical valve portion slidably inserted into the inner periphery of the inflow passage of the port portion is provided at the distal end of the plunger, and A solenoid valve having an opening which is gradually opened by axial movement of a plunger on a side wall of a valve portion. 2. The bearing member according to claim 1, wherein a fitting tube portion fitted and fixed to an inner periphery of the inflow passage of the port portion is provided, and a gap is provided between an outer periphery of the bearing member and an inner periphery of the solenoid. 2. The solenoid valve according to item 1. 3. The bearing member has a regulating surface that regulates the position of the plunger when the plunger is urged toward the port by the spring force of a spring, and does not face the fluid flow path. The solenoid valve according to claim 1 or 2, wherein 4. A center post, a solenoid provided so as to surround the center post, a port portion provided at a predetermined interval in the axial direction from the center post, an inner peripheral surface of the solenoid, a center post and a port. A plunger movably inserted in an axial direction into a plunger chamber formed by an opposing surface of the portion, a spring inserted between the plunger and the center post to press the plunger against a port portion, and the port And an inflow passage provided in the portion, by energizing the solenoid to attract the plunger to the center post side against the spring force of the spring, and by changing the amount of electricity to the solenoid to change the attraction force In a solenoid valve for controlling an opening amount of an outlet of the inflow passage on the plunger chamber side, a tip of the plunger A cylindrical valve portion that is slidably inserted into the inner periphery of the inflow passage of the port portion, and an opening portion that is gradually opened by axial movement of the plunger is provided on a side wall of the cylindrical valve portion; A solenoid valve provided with a cylindrical valve sleeve for supporting a cylindrical valve portion. 5. A center post, a solenoid provided to surround the center post, a plunger attracted by excitation of the solenoid, a valve which moves in accordance with the movement of the plunger, and a valve which moves the valve to the plunger side. A spring having pressure and a port having an inflow path, wherein the solenoid is excited to attract the plunger to the center post side against the spring force of the spring, and to vary the amount of electricity supplied to the solenoid to attract the plunger. A solenoid valve for controlling an opening amount of an outlet on the valve side of the inflow passage by changing a force, wherein a cylindrical valve portion slidably inserted into an inner periphery of the inflow passage of a port at a tip end of the valve. Characterized in that an opening is provided on the side wall of the cylindrical valve portion, the opening being gradually opened by the axial movement of the plunger. Valve.