JP2001227672A - Solenoid valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solenoid valve easy to manufacture and having a stable control characteristic for a long period of time. SOLUTION: A plunger 19 and a spool valve 20 are independently provided, are the control characteristic of this solenoid valve 1 is made appropriate by adjusting an effective valve stroke by the adjustment of press-in quantity in pressing the spool valve 20 into the plunger 19. A finished product can therefore be obtained without the control characteristic being influenced by a spring 8 and a support member 17 built in afterwards, and this results in obtaining the solenoid valve 1 of good quality with the appropriate control characteristic.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a current control electromagnetic variable relief valve used for hydraulic control, for example, and more particularly to a solenoid valve applied to hydraulic control of an automatic transmission for an automobile.

[0002]

2. Description of the Related Art A conventional solenoid valve of this type is known, for example, as shown in FIG. The solenoid valve 101 includes a solenoid 102 and a valve unit 103.

A solenoid 102 includes a coil 104 wound in a cylindrical shape, a center post 105 fixedly disposed on the inner peripheral side of the coil 104, and a valve portion 1 of the center post 105.
A plunger 107 movably inserted in the axial direction into a plunger chamber 106 formed on the side of the valve 03, and a spring inserted between the plunger 107 and the center post 100 to press the plunger 104 against the valve unit side. 108.

The valve section 103 includes a spool valve 119 provided at an end of the plunger 107, and a valve sleeve 120 sliding on the outer periphery of the spool valve 119.

The valve section 103 is provided with a supply pressure port SP penetrating in the axial direction. The center post 105 is provided with a drain port DP.
A pilot pressure port PP is provided at the base of 03.

Then, the solenoid 102 is excited, and the plunger 107 is attracted to the center post 105 against the spring force of the spring 108, thereby connecting the supply pressure port SP and the pilot pressure port PP to control the fluid. Is going.

[0007]

However, the solenoid valve 101 of the prior art has the following problems.

As a method of adjusting the control characteristics of the solenoid valve 101, there are generally a method of adjusting the set load of the spring 108 and a method of adjusting the valve stroke. Particularly, in the method of adjusting the valve stroke, the center post 105 is adjusted. It was common to move and adjust by screwing or press fitting.

A specific example of the screwing of the center post 105 will be described. For example, a male screw portion 105a is provided on the outer periphery of the center post 105, and a female screw portion 112a meshing with the male screw portion is provided on the upper plate 112. The center post 105 is screwed into the solenoid 102 for adjustment, and then the center post 105 and the upper plate 1 are adjusted.
12 was caulked and made a finished product.

However, when the center post 105 is screwed or press-fitted as a method for adjusting the effective valve stroke, the structure of the solenoid valve 101 itself becomes complicated because the center post 105 is movable. Costs up.

After the adjustment, the center post 105 is adjusted.
In order to caulk the upper plate 112 and the finished product, if the control characteristics are deteriorated due to an impact or the like at the time of caulking after the adjustment is completed, appropriate control characteristics at the time of adjusting the solenoid valve 101 are obtained in the completed product. There was nothing.

Next, the conventional solenoid valve 1 will be described.
01, the spool valve 119 and the valve sleeve 12
The spool valve 119 is mounted on the valve sleeve 1 by an amount corresponding to the clearance between the outer peripheral surfaces of the spool valve 119 and the inner peripheral surface of the valve sleeve 120.
May lean to 20.

When the spool valve 119 is inclined with respect to the valve sleeve 120, the spool valve 119 makes line contact at two points, that is, the tip of the spool valve 119 and the end of the valve sleeve 120 when the valve is closed. As shown, only the edge of the opening 119a of the spool valve 119 and the edge of the end of the valve sleeve 120 may come into contact with each other to form a point contact. When this point contact state is repeated, the point contact portion wears out, and the control characteristics of the solenoid valve 101 may change.

The wear of the point contact portion causes the solenoid valve 10
Since the control characteristics do not recover if the control characteristics of the solenoid valve 101 change, the durability of the solenoid valve 101 is limited.
It has been difficult to extend the life of the steel.

Furthermore, in the conventional solenoid valve, as shown in FIG.
When foreign matter (contamination) I contained in the fluid enters the clearance between the sliding surfaces of the outer circumference and the inner circumference of the valve sleeve 120, sliding resistance is generated. As a result, the spool valve 119 cannot move smoothly, and the control characteristics are changed, which impairs the control function. Depending on the degree, the spool valve 119 may be caught and the solenoid valve 101 may become inoperable.

The foreign matter that has entered the clearance portion is carried by the flow of the fluid and drops from the clearance portion, thereby restoring the valve function. However, the longer the sliding surfaces of the sliding portions are, the longer the foreign matter is required to drop off. , The time until the valve function is restored becomes longer.

As described above, from the viewpoint of the contamination resistance of the clearance portion for stabilizing the control characteristics, it is better that the length of the sliding surfaces of the sliding portions is shorter. In order to reduce the contact of the sliding part with respect to the side, it is necessary to provide the sliding surfaces of the sliding parts long, or to provide the sliding parts at two separate positions.

Spool valve 119 and valve sleeve 1
FIG. 14 shows an example in which two sliding portions 20 are provided. In FIG. 14, the sliding parts 119e,
119f are provided at two places. In such a case, it is difficult to manufacture with high accuracy, which has led to an increase in cost.

An object of the present invention is to solve the above-mentioned problems of the prior art, and an object of the present invention is to provide a solenoid valve which is easy to manufacture and has stable control characteristics for a long period of time.

[0020]

In order to achieve the above object, according to the present invention, there is provided a center post fixedly disposed inside a solenoid, and a center post provided opposite to the center post and movable in an axial direction. A solenoid valve comprising a plunger, a spool valve interlocked with the plunger, and a valve sleeve sliding on an outer peripheral surface of the spool valve, wherein the center post has a through hole penetrating in the axial direction, And the spool valve are separately provided, and the jig inserted from both sides in the axial direction through the inside of the valve sleeve and the through hole of the center post press-fits the spool valve to the plunger, And that the effective valve stroke is adjusted by adjusting the axial length of the spool valve according to the press-fit amount. To.

Here, the effective valve stroke refers to a difference between a position where the spool valve starts to open and a position where the spool valve reaches the maximum opening.

Therefore, the valve stroke is adjusted to make the control characteristics of the solenoid valve appropriate, and the subsequent incorporation of parts does not affect the control characteristics. Therefore, it is possible to obtain a finished solenoid valve with proper control characteristics and good quality. it can.

In addition, since the adjustment can be performed with a simple structure in which the plunger and the spool valve are separated, the cost can be reduced as compared with the conventional technique.

A center post fixedly disposed inside the solenoid, a plunger provided opposite to the center post and movable in the axial direction, a spool valve interlocked with the plunger and having an opening for allowing fluid to pass therethrough; ,
A valve sleeve that slides on the outer peripheral surface of the spool valve, wherein an annular groove forming a clearance between the entire outer peripheral surface around the opening of the spool valve and the inner peripheral surface of the valve sleeve. Is good.

With this arrangement, it is possible to prevent the edge of the opening from coming into contact with the edge of the end of the valve sleeve in the open state of the valve to form a point contact. Therefore, the life of the solenoid valve can be extended.

Further, since the annular groove has a space around the opening of the spool valve with respect to the inner peripheral surface of the valve sleeve, even if a minute burr is formed around the opening during processing of the opening. The sliding of the spool valve with respect to the valve sleeve is not affected.

A center post fixedly arranged inside the solenoid, a plunger provided opposite to the center post and movable in the axial direction, a spool valve interlocked with the plunger, and an outer peripheral surface of the spool valve. And a valve sleeve having an inner peripheral surface that slides, wherein a dividing groove is provided for dividing a portion in which the outer peripheral surface of the spool valve slides and the inner peripheral surface of the valve sleeve into a plurality of parts in the axial direction. Is good.

As a result, the portion where the outer peripheral surface of the spool valve slides and the inner peripheral surface of the valve sleeve slide in the dividing groove is divided into a plurality in the axial direction, but the distance to both ends of the divided sliding portion is constant. Therefore, the spool valve is prevented from tilting, so that the spool valve can be prevented from hitting one side.

The sliding resistance caused by foreign matter (contamination) contained in the fluid entering the clearance between the sliding surface of the spool portion at the sliding portion and the sliding surface of the inner periphery of the valve sleeve due to the dividing groove is reduced. Is provided, and the sliding portion is shortened, so that the sliding portion is reduced, and the control characteristics are stabilized. Even in the case of control failure, the sliding portion is short, so that the foreign matter falls off from the clearance portion at an early stage, so that the time until the return is short.

Further, since the two sliding portions divided by the dividing grooves are provided with the same outer diameter, centerless processing becomes possible, processing is easy, and the outer diameter can be created with high precision. The movement of the spool valve is stabilized, the control of the solenoid valve is stabilized, and the machining can be performed at two places at the same time as compared with the one having two sliding parts having different diameters, so that the cost can be reduced.

It is preferable to provide a passage for making the gap formed by the dividing groove between the outer peripheral surface of the spool valve and the inner peripheral surface of the valve sleeve equal to the supply pressure.

As a result, the gap between the dividing groove and the inner peripheral surface of the valve sleeve becomes equal in pressure to the supply pressure by the passage, so that it is difficult for foreign substances to enter the sliding portion at the tip of the valve sleeve, and the control characteristics are stable. I do.

Further, since the fluid pressure is lower around the plunger, foreign matter that has entered the gap between the dividing groove and the inner peripheral surface of the valve sleeve is passed through the sliding portion of the divided plunger side to flow. As it goes, the control characteristics are stabilized.

[0034]

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the dimensions of the components described in this embodiment,
The materials, shapes, relative arrangements, and the like are not intended to limit the scope of the present invention only to them unless otherwise specified.

(First Embodiment) First, a hydraulic control system for controlling the hydraulic pressure of an automatic transmission for a vehicle to which the solenoid valve of the present embodiment is applied will be described with reference to FIG.

In FIG. 5, a pressure reducing valve 502 is connected to a line pressure oil passage 501 to which a line pressure L is supplied, and a solenoid supply pressure S controlled to a constant pressure by the pressure reducing valve 502 is supplied to the solenoid supply pressure oil passage. It is supplied at 503 and guided to the supply pressure port SP of the solenoid valve 1.

The solenoid valve 1 has a supply pressure port S
In addition to P, a drain port DP and a pilot pressure port PP are provided. From the pilot pressure port PP, a pilot pressure P controlled by the solenoid valve 1 is guided to a pilot pressure oil passage 504 communicating with the spool valve 505. I will

The spool valve 505 has a line pressure oil passage 50
1, the pilot pressure oil passage 504 and the output pressure oil passage 506 are connected. The output pressure O guided to the output pressure oil passage 506 by the spool valve 505 is controlled by the line pressure L as the base pressure and the pilot pressure P as the operation signal pressure controlled by the solenoid valve 1.

The output pressure oil passage 506 is connected to a piston oil chamber of a clutch and the like when not shown, and controls the clutch and the like according to the magnitude of the output pressure.

In the above hydraulic control system, when the solenoid valve 1 is energized, the supply pressure port SP communicates with the pilot pressure port PP, and the drain port DP is shut off. Also, when the power is not supplied, the supply pressure port SP is shut off,
The pilot pressure port PP communicates with the drain port DP.

Thus, the pilot pressure P of the pilot pressure oil passage 504 can be controlled in the range of 0 to the solenoid supply pressure S.

The structure of the solenoid valve will be described with reference to FIG. Solenoid valve 1 is connected to solenoid 2
And a valve section 3.

The solenoid 2 includes a coil 4 wound in a cylindrical shape and a center post 5 fixedly disposed on the inner peripheral side of the coil 4.
And a plunger 7 that is axially movably inserted into a plunger chamber 6 formed on the valve portion 3 side of the center post 5 and that is provided to face the center post 5. A spring 8 inserted between the springs to press the plunger 7 against the valve portion 3.

The solenoid 2 has a structure in which the coil 4 is wound around the bobbin 9. The center post 5 is fitted to the inner periphery of the bobbin 9 on the side opposite to the valve section 3, and the half of the valve section 3 becomes the plunger chamber 6. The valve section 3 is provided so as to close the opening of the plunger chamber 6 on the valve section 3 side.

A lower plate 10 is provided in contact with the end face of the solenoid 2 on the valve section 3 side. The lower plate 10 has a cylindrical shape with an outward flange.
b contacts the end face of the solenoid 2 on the valve section 3 side, and the cylindrical section 10a is embedded in the inner periphery of the bobbin 9 of the solenoid 2. The inner periphery of the cylindrical portion 10a of the lower plate 10 is covered with a thin resin portion 2a.

The bobbin 9, the thin resin portion 2a, and the cylindrical portion 11 forming the outer peripheral wall of the valve portion are integrally formed by inserting a lower plate 10.

The end of the center post 5 on the side opposite to the valve portion 3 further protrudes from the end of the solenoid 2, and an annular yoke forming a magnetic path is formed at the end of the center post 5 on the side opposite to the valve portion 3. The inner diameter end of the upper plate 12 is fixed.

A connector 13 is interposed between the upper plate 12 and the solenoid 2. 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 2 is embedded in the connector 13.

The solenoid 2 is housed in a case 15,
The outer diameter end of the upper plate 12 is fitted and fixed to the end opening of the case 15 on the side opposite to the valve portion 3.
The outer diameter end of the flange portion 10b of the lower plate 10 is fitted and fixed to the side end opening.

Thus, the magnetic circuit H when the solenoid 2 is excited is formed so as to return to the center post 5 through the center post 5, the plunger 7, the lower plate 10, the case 15, and the upper plate 12.

The case 15 is provided with a mounting plate 16, and the solenoid valve 1 is fixed at a predetermined position by the mounting plate 16.

The center post 5 is provided with a through hole 51 penetrating in the axial direction and communicating with the drain port DP. A support member 17 for adjusting the set load of the spring 8 and supporting the spring is fixed to the through hole 51. Have been. Also,
One end of a spring 8 is engaged with an end of the support member 17 facing the plunger chamber 6.

The end face of the center post 5 facing the plunger chamber 6 is a tapered surface that gradually projects toward the plunger chamber 6 from the inner diameter end toward the outer diameter end. It faces the tip of the cylindrical portion 10a at a predetermined interval in the axial direction. The end face has a plunger 7
A stopper 18 is provided so as to come into close contact with the plunger 7 when is attracted to the center post 5.

The plunger 7 has a smaller diameter than the inner diameter of the solenoid 2, a large-diameter portion 71 having a predetermined annular gap between the inner periphery of the solenoid 2, and a valve portion 3 extending from the end of the large-diameter portion 71 on the valve portion 3 side. And a small-diameter portion 72 whose end face is in contact with the end of the valve sleeve 20.

The anti-valve portion 3 of the large diameter portion 71 of the plunger 7
A concave portion 73 is formed on the side end surface, and the other end of the spring 8 is fitted into the concave portion 73 and positioned. A concave portion 74 is also formed on the end surface of the small diameter portion 72 on the valve portion 3 side, and the spool valve 19 of the valve portion 3 is press-fitted into the concave portion 74.

There is a gap between the outer periphery of the plunger 7 and the inner wall surface of the plunger chamber 6 so that the fluid can move in the axial direction.

The valve section 3 has a small diameter section 72 of the plunger 7.
A spool valve 19 press-fitted into the concave portion 74, a valve sleeve 20 sliding on the outer periphery of the spool valve 19,
A cylindrical portion 11 forming an outer peripheral wall.

The valve sleeve 20 is fixed to the inner periphery of the cylindrical portion 11 and has a uniform inner diameter.

An O-ring 21 is provided around the outer periphery of the cylindrical portion 11 to exhibit a sealing property when the cylindrical portion 11 is fitted into a mounting hole or the like.
Is installed.

The inside of the spool valve 19 penetrates in the axial direction and serves as a supply pressure port SP. And
The fluid of the solenoid supply pressure S of the solenoid supply pressure oil passage 503 flows into the solenoid valve 1 from the supply pressure port SP.

A pilot pressure port PP is provided at the base of the valve section 3. A pilot pressure P controlled by the solenoid valve 1 is guided from the pilot pressure port PP to the pilot pressure oil passage 504.

The pilot pressure port PP communicates with the drain port DP via the through hole 51 of the plunger chamber 6 and the center post 5 when the valve is closed, and communicates with the supply pressure port SP when the valve is open.

Here, the spool valve 19 will be described in more detail with reference to FIGS.

The spool valve 19 has an opening 19 a through which fluid flows to the pilot pressure port PP, an annular groove 19 b that makes the entire outer peripheral surface around the opening 19 a non-slidable with the inner peripheral surface of the valve sleeve 20, and an opening. A dividing groove 19c that divides a sliding portion composed of sliding surfaces between the outer periphery of the spool valve 19 and the inner periphery of the valve sleeve 20 closer to the solenoid supply pressure oil passage 503 than the portion 19a into two in the axial direction; A hole 19 d as a passage penetrating the inner periphery of the spool valve 19 at the provided portion.

When the valve is opened, that is, when the plunger 7 is attracted to the center post 5, the opening 19a separates from the inner peripheral surface of the valve sleeve 20 and connects the supply pressure port SP to the pilot pressure port PP.

The annular groove 19b prevents the edge of the opening 19a from contacting the edge of the end of the valve sleeve 20, and has a diameter smaller than the outer diameter of the sliding portion over the entire circumference. The groove side surface of the annular groove is provided perpendicular to the axial direction.

The dividing groove 19c is formed in an annular shape provided on the entire circumference in the same manner as the annular groove 19b, and the portion provided with the dividing groove 19c has a gap between it and the inner peripheral surface of the valve sleeve 20. Two sliding portions are provided so that the outer periphery of the spool valve 19 slides on the inner periphery of the valve sleeve 20. Here, the sliding portion at the tip of the spool valve 19 is referred to as a first sliding portion 19e, and the sliding portion on the plunger 7 side is referred to as a second sliding portion 19f.

The hole 19d is provided such that a gap between the dividing groove 19c and the inner peripheral surface of the valve sleeve 20 communicates with the inside of the spool valve 19, and the gap is formed by the spool valve 19c.
The inner supply pressure S is made equal to the inner supply pressure S.

Also, as shown in FIG.
9 is a separate body from the plunger 7 and has a spool valve 19.
Into the recess 74 on the end face of the small diameter portion 72 of the plunger 7,
As shown in FIG. 3, the spool valve 19 and the plunger 7 are integrated.

In the solenoid valve 1 of the present embodiment, the solenoid 2 is excited, and the plunger 7 is attracted to the center post 5 against the spring force of the spring 8, thereby opening the opening 19 a of the spool valve 19. Is separated from the inner peripheral surface of the valve sleeve 20 to open the valve,
The supply pressure port SP communicates with the pilot pressure port PP. At this time, the plunger 7 comes into close contact with the stopper 18 provided on the center post 5 to shut off the drain port DP.

On the other hand, when the solenoid 2 is not energized, the plunger 7 is pressed against the valve section 3 by the spring force of the spring 8, so that the spool valve 19 is located in the valve sleeve 20 and the valve is closed, and the supply pressure port SP is closed. Blocked, the through hole 51 of the center post 5 and the plunger chamber 6
Pressure port PP and drain port DP via
Communicate.

Here, in the solenoid valve 1 of the present embodiment, at the time of manufacturing, as shown in FIG.
In the stage before the spring 8 and the support member 17 are assembled after performing the caulking of No. 5, the total length in the axial direction including the plunger 7 and the spool valve 19 is changed to adjust the effective valve stroke, and the control characteristics of the solenoid valve 1 are adjusted appropriately. I have to.

Here, the effective valve stroke refers to the difference between the position where the spool valve 19 starts to open and the position where the spool valve 19 reaches the maximum opening.

As described above, since the plunger 7 and the spool valve 19 are integrated by press-fitting, by adjusting the amount of press-fit of the spool valve 19 into the plunger 7, the total length of the spool valve 19 press-fitted and integrated with the plunger 7 is reduced. Can be varied, thereby adjusting the valve stroke to optimize the control characteristics.

Before the spring 8 and the support member 17 are assembled, the solenoid valve 1 is connected to the plunger 7 and the spool valve 19 so that the press-fit amount can be adjusted.
The both sides in the axial direction of the supply pressure port SP side and the drain port DP side are opened to the outside.

Then, as shown in FIG. 4, a jig 401 is inserted from both sides of the opened axial direction, and the jig 401 presses the concave portion 73 of the plunger 7 and the end of the spool valve 19 on the supply pressure port SP side. The spool valve 19 is press-fitted into the plunger 7 while adjusting the press-fit amount.

In this adjustment, not only the total length of the plunger 7 and the spool valve 19 can be changed, but also the position of the opening 19a of the spool valve 19 can be adjusted.

After the control characteristics of the solenoid valve 1 are adjusted appropriately, the spring 8 is inserted through the through hole 51 of the center post 5 and installed, and the support member 17 is fixed in the through hole 51 to fix the solenoid valve. 1 has been completed.

Therefore, in this embodiment, the plunger 7 and the spool valve 19 are provided separately, and the effective valve stroke is adjusted by adjusting the amount of press-fitting when the spool valve 19 is press-fitted into the plunger 7, so that the solenoid is controlled. Since the control characteristics of the valve 1 are made appropriate, the finished product can be manufactured without being affected by the control characteristics of the spring 8 and the support member 17 incorporated thereafter, and the solenoid valve 1 with good control characteristics and high quality can be obtained. be able to.

The plunger 7 and the spool valve 19
Can be adjusted with a simple configuration in which the center post 5 is not screwed or press-fitted as in the related art, and the cost can be reduced as compared with the related art.

On the other hand, as shown in FIG. 2, the spool valve 19 is provided with an annular groove 19b on the outer peripheral surface of the spool valve 19 around the opening 19a. Point contact can be prevented by contacting the edge of the end of the valve sleeve 20.

In particular, the annular groove 19b is provided on the entire circumference, and the groove side surface of the annular groove 19b is perpendicular to the axial direction. Since the line is only in line contact with the edge of the 20 end, deterioration of durability due to point contact wear does not occur, and the life of the solenoid valve 1 can be extended.

Further, since the periphery of the opening 19a of the spool valve 19 has a gap with respect to the inner peripheral surface of the valve sleeve 20 due to the annular groove 19b, a minute space around the opening 19a is formed when the opening 19a is processed. Even if the burr is generated, the sliding of the spool valve 19 with respect to the valve sleeve 20 is not affected.

The annular groove 19b can be variously modified in addition to the present embodiment, such as being provided on the valve sleeve 20 side as shown in FIG. FIG. 6 shows an example in which a spool valve 19 is integrated with the plunger 7 (here, a spool valve 19 having a plunger portion and a spool valve portion).
This is a model in which only the annular groove 19b is taken up.

FIGS. 6 (a) and 6 (b) have an annular groove 19b in the spool valve portion as in the present embodiment. In particular, in FIG. 6B, the side face of the annular groove 19b on the side opposite to the valve section 3 is the end face of the plunger section.
In 9, when the valve is closed, the end face of the plunger portion and the end face of the valve sleeve abut.

FIG. 6C shows an arrangement in which an annular groove 19a is provided on the valve sleeve 20 side, and the same effect can be obtained by this.

The spool valve 19 has a dividing groove 19c.
Are provided, and the sliding portions are provided at two locations (first and second sliding portions 19e and 19f) in the axial direction.
Since the distance to both ends of 19f is constant, the inclination of the spool valve 19 is prevented, so that the spool valve 19 can be prevented from hitting one side.

The sliding portions 19e, 19
The sliding resistance caused by the entry of foreign matter (contamination) contained in the fluid into the clearance between the sliding surface f and the sliding surface on the inner periphery of the valve sleeve is reduced by the provision of the dividing groove 19c as shown in FIG. It is reduced by shortening itself, and the control characteristics are stabilized. When the control failure occurs, the sliding portions 19e, 1
Since 9f is short, the foreign matter drops off from the clearance portion at an early stage, so that the time until restoration is short (the arrow indicates the flow of foreign matter I in FIG. 7).

Further, since the two sliding portions 19e and 19f divided by the dividing groove 19c are provided with the same outer diameter, centerless processing can be performed, the processing is easy, and the outer diameter is created with high precision. As a result, the movement of the spool valve 19 is stabilized, the control of the solenoid valve 1 is stabilized, and the machining can be performed at two places at the same time as compared with the one having two sliding parts having different diameters, so that the cost can be reduced. it can.

It is to be noted that the division groove 19c can be variously modified, for example, provided on the valve sleeve 20 side as shown in FIG. 8B, or provided with a plurality of sliding portions at three or more places. FIG. 8 is a model in which only the dividing groove 19c is taken up similarly to FIG.

Further, a hole 19d penetrating through the inner and outer peripheries at the portion where the dividing groove 19c is provided is provided, and the gap between the dividing groove 19c and the inner peripheral surface of the valve sleeve 20 communicates with the inside of the spool valve 19, Since the gap is equal in pressure to the supply pressure S inside the spool valve 19, it is difficult for foreign matter to enter the first sliding portion 19e.

Also, since the fluid pressure is lower around the plunger 7 through the opening 19a of the spool valve 19, foreign matter that has entered the gap between the dividing groove 19c and the inner peripheral surface of the valve sleeve 20 will not pass through the second slide. Moving part 19f and valve sleeve 20
The foreign matter I flows while passing through the gap between the inner peripheral surface (see FIG. 9, arrows).

In this embodiment, the passage 19d is provided as a passage on the inner and outer periphery of the spool valve 19.
Various modifications are possible, such as providing a passage 20a provided inside the valve section 3 and circling outside the supply pressure port SP as shown in FIG. 10 (b). FIG. 10 is a model similar to FIGS. 6 and 8 in which only a passage for making the gap formed by the dividing groove 19c between the outer peripheral surface of the spool valve 19 and the inner peripheral surface of the valve sleeve 20 equal to the supply pressure is taken up. .

[0094]

As described above, according to the present invention, the center post has a through hole penetrating in the axial direction, the plunger and the spool valve are provided separately, and the inside of the valve sleeve and the center post are provided. The spool valve is pressed into the plunger by the jigs inserted from both sides in the axial direction through the through holes, and the axial lengths of the plunger and the spool valve are adjusted by the press-fitting amount to adjust the effective valve stroke. As a result, the control characteristics of the solenoid valve become appropriate, and the subsequent incorporation of components does not affect the control characteristics, so that it is possible to obtain a finished solenoid valve with appropriate control characteristics and good quality.

Further, since the adjustment can be performed with a simple structure in which the plunger and the spool valve are separated, the cost can be reduced as compared with the prior art.

By providing an annular groove which forms a gap between the entire outer peripheral surface around the opening of the spool valve and the inner peripheral surface of the valve sleeve, the edge of the opening is closed at the end of the valve sleeve when the valve is open. Point contact due to contact with the edge can be prevented, durability does not deteriorate due to point contact wear, and control characteristics are stabilized for a long time, so that the life of the solenoid valve can be extended.

[0097] Further, since the periphery of the opening of the spool valve has a gap with respect to the inner peripheral surface of the valve sleeve due to the annular groove, even when a small burr is generated around the opening during processing of the opening. The sliding of the spool valve with respect to the valve sleeve is not affected.

By providing a dividing groove for dividing a portion where the outer peripheral surface of the spool valve and the inner peripheral surface of the valve sleeve slide into a plurality of parts in the axial direction, the outer peripheral surface of the spool valve and the inner peripheral surface of the valve sleeve slide by the dividing groove. The divided portion is divided into a plurality of portions in the axial direction. However, since the distance to both ends of the divided sliding portion is constant, the spool valve is prevented from tilting, so that the spool valve can be prevented from coming into contact with one side.

The sliding resistance generated by foreign matter (contamination) contained in the fluid entering the clearance between the sliding surfaces of the outer periphery of the spool valve and the inner periphery of the valve sleeve in the sliding portion due to the divided groove is reduced. Is provided, and the sliding portion is shortened, so that the sliding portion is reduced, and the control characteristics are stabilized. Even in the case of control failure, the sliding portion is short, so that the foreign matter falls off from the clearance portion at an early stage, so that the time until the return is short.

Further, since the two sliding portions divided by the dividing grooves are provided with the same outer diameter, centerless processing can be performed, the processing is easy, and the outer diameter can be created with high accuracy. The movement of the spool valve is stabilized, the control of the solenoid valve is stabilized, and the machining can be performed at two places at the same time as compared with the one having two sliding parts having different diameters, so that the cost can be reduced.

By providing a passage for making the gap formed by the dividing groove between the outer peripheral surface of the spool valve and the inner peripheral surface of the valve sleeve equal to the supply pressure, the gap between the dividing groove and the inner peripheral surface of the valve sleeve is provided. Since the gap becomes equal to the supply pressure by the passage, it becomes difficult for foreign matter to enter the sliding portion at the tip of the valve sleeve, and the control characteristics are stabilized.

Further, since the fluid pressure is lower around the plunger, foreign matter that has entered the gap between the dividing groove and the inner peripheral surface of the valve sleeve is passed through the sliding portion of the divided plunger side to flow. As it goes, the control characteristics are stabilized.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a solenoid valve according to an embodiment.

FIG. 2 is a sectional view and a top view showing a spool valve and a plunger according to the embodiment.

FIG. 3 is a cross-sectional view and a top view showing a state where the spool valve and the plunger according to the embodiment are integrated.

FIG. 4 is a cross-sectional view showing a state at the time of adjusting the effective valve stroke of the solenoid valve according to the embodiment.

FIG. 5 shows a hydraulic control system to which a solenoid valve is applied.

FIG. 6 is a model diagram showing another example of the annular groove of the present invention.

FIG. 7 is an explanatory view showing the operation of the dividing groove of the present invention.

FIG. 8 is a model diagram showing another example of the annular groove of the present invention.

FIG. 9 is an explanatory view showing the operation of the hole of the present invention.

FIG. 10 is a model diagram showing another example of the passage of the present invention.

FIG. 11 is a longitudinal sectional view showing a conventional solenoid valve.

FIG. 12 is a diagram showing a point contact state between a spool valve and a valve sleeve.

FIG. 13 is an explanatory diagram illustrating a state in which a foreign object has entered a clearance portion.

FIG. 14 is a view showing a spool valve provided with two sliding portions.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Solenoid valve 2 Solenoid 3 Valve part 4 Coil 5 Center post 51 Through hole 6 Plunger chamber 7 Plunger 8 Spring 9 Bobbin 10 Lower plate 10a Cylindrical part 10b Flange part 11 Cylindrical part 12 Upper plate 13 Connector part 14 Socket part 14a Terminal 15 Case 16 Mounting plate 17 Support member 18 Stopper 19 Spool valve 19a Opening 19b Annular groove 19c Dividing groove 19d Hole 19e First sliding part 19f Second sliding part 20 Valve sleeve 21 O-ring SP Supply pressure port PP Pilot pressure port DP Drain port

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3H106 DA07 DB02 DB12 DB23 DB32 DC09 DC18 DD03 EE30 EE35 EE42 EE48 GA25 GB06 GC02 JJ03 KK03 KK17

Claims (4)

[Claims] 1. A center post fixedly arranged inside a solenoid, a plunger provided to face the center post and movable in an axial direction, a spool valve interlocked with the plunger, and an outer peripheral surface of the spool valve A center sleeve having a through hole extending in an axial direction, the plunger and the spool valve being provided separately, an inner side of the valve sleeve and the center. The jig inserted from both sides in the axial direction through the through hole of the post press-fits the spool valve to the plunger, and the axial length of the plunger and the spool valve is adjusted by the press-fit amount to be effective. A solenoid valve whose valve stroke is adjusted. A center post fixedly disposed inside the solenoid, a plunger provided opposite to the center post and movable in an axial direction, and a spool having an opening interlocked with the plunger and allowing fluid to pass therethrough. A solenoid valve comprising: a valve; and a valve sleeve sliding on an outer peripheral surface of the spool valve, wherein a gap is formed between the entire outer peripheral surface around the opening of the spool valve and the inner peripheral surface of the valve sleeve. Solenoid valve characterized by having an annular groove. A center post fixedly disposed inside the solenoid; a plunger provided to face the center post and movable in an axial direction; a spool valve interlocked with the plunger; and an outer peripheral surface of the spool valve. And a valve sleeve having an inner peripheral surface that slides with respect to the solenoid valve, wherein a dividing groove that divides a portion where the outer peripheral surface of the spool valve slides and the inner peripheral surface of the valve sleeve into a plurality of parts in the axial direction is provided. A solenoid valve. 4. A passage provided to equalize a supply pressure with a gap formed by the dividing groove between the outer peripheral surface of the spool valve and the inner peripheral surface of the valve sleeve. The described solenoid valve.