JP2003097739A - Structure for preventing rotation of spool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure for preventing rotation of a spool energized and inserted into a slide hole of a valve element by a spring. SOLUTION: This structure 28 for preventing rotation has an abutting face 44 formed on the spool 26 with extending in a shaft line 27 direction and an abutting body 48 fixed on a spacer 46 interposed between the valve element 22 and a spring housing 10 and abutted against the abutting face 44 for preventing rotation of the spool 26 in the slide hole 24.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spool detent structure for a spool valve.

[0002]

2. Description of the Related Art As a typical example of a spool valve, there is a well-known directional control valve for supplying / discharging hydraulic oil from a hydraulic source to an actuator such as a hydraulic cylinder to control its expansion / contraction operation. Explaining with reference to FIG. 7, in this directional control valve, a spool 6 slidably inserted in a sliding hole 4 of a valve body 2 is
A spring 8 attached to the end of the spool 6 biases the spool 6 in the direction of the axis 7 and normally keeps the neutral position (the state shown in FIG. 7) to stop the supply of hydraulic oil to the actuator. . When pilot pressure oil is applied to the end portion of the spool 6, for example, the end portion shown in the drawing, through the port 9 by the operating means (not shown), the pressure oil causes the spool 6 to resist the biasing force of the spring 8. The hydraulic fluid is supplied to the hydraulic cylinder by being slid inward of the sliding hole 4, being positioned at the operating position, opening the flow path.

The spring 8 is sandwiched between a pair of spring receivers 12 and 14 in a housing 10 attached to the opening end of the sliding hole 4 of the valve body 2, and the spring receiver 1
It is fixed to the end of the spool 6 with bolts 16 together with the bolts 2 and 14. One spring receiver 12 is in contact with the ends of the valve body 2 and the spool 6, and the other spring receiver 14 is in contact with the inner surface of the housing 10.

[0004]

The conventional spool valve having the above-mentioned configuration has the following problems to be solved.

That is, when the spool 6 is operated to the operating position and the hydraulic fluid supplied to and discharged from the hydraulic actuator passes through the spool 6, the spool 6 moves in the direction of the axis 7 as the flow rate increases. It is a well-known force that tries to do so, or tries to rotate in the circumferential direction,
Flow force is generated. In particular, the force to rotate is applied to the contact portion where the spool 6 and the valve body 2 are in contact with the spring receiver 12, and the housing 10 and the spring receiver 1.
Relative movement in the rotational direction is generated at the contact portion with which the abutment 4 contacts, and the contact portions such as the valve body 2, the spool 6, and the spring receivers 12 and 14 are worn. When this wear progresses, the neutral position, the operating position, etc. of the spool 6 in the direction of the axis 7 change, and there arises a problem that the flow of the hydraulic oil cannot be properly controlled.

The present invention has been made in view of the above facts, and its technical problem is to provide a detent structure for stopping the rotation of a spool which is urged by a spring and inserted into a sliding hole of a valve body of a spool valve. Is to provide.

[0007]

That is, according to the present invention, a structure for preventing rotation of a spool, which is urged by a spring and inserted into a sliding hole of a valve body of a spool valve, which solves the above technical problems, is provided. The spool is provided with an abutment surface formed to extend in the axial direction of the spool, and an abutment body attached to the valve body side to abut the abutment surface to stop the rotation of the spool in the sliding hole. A structure for preventing rotation of a spool is provided.

Then, the abutment surface formed on the spool and the abutment body attached to the valve body are brought into contact with each other,
Stop spinning the spool.

In the preferred embodiment, the contact surface is formed by a flat surface. The contact surface may have an arcuate cross section and extend in a groove shape. The contact body has a spherical surface that contacts the corresponding contact surface. And it is formed of a sphere. Further, the spring is attached to an end of the spool, a housing for accommodating the spring is attached to an opening end of a sliding hole of the valve body via a spacer member, and a corresponding contact body is attached to the spacer member. Has been.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION A spool detent structure constructed according to the present invention will be described in more detail below with reference to the accompanying drawings illustrating preferred embodiments.
Note that the substantially same parts as those in FIG. 7 are denoted by the same reference numerals.

Referring to FIG. 1, a directional control valve, generally indicated by numeral 20, which is a typical example of a spool valve, has a spool 26 slidably inserted in a slide hole 24 of a valve body 22.
And a spring 8 attached to one end of the spool 26 (the right end in FIG. 1) via spring receivers 12 and 14 to bias the spool 26 in the direction of its axis 27.

The spring 8 is a compression spring,
It is sandwiched between the spring receivers 12 and 14 in the housing 10 which is attached to one opening end (the right end in FIG. 1) of the sliding hole 24 of the valve body 22 via a spool detent structure 28. The spring receivers 12 and 14 are fixed to the end of the spool 26 by bolts 16. One spring receiver 12 is in contact with the end portions of the spool detent structure 28 and the spool 26, and the other spring receiver 14 is in contact with the inner surface of the housing 10, and the spool 26 is held in the neutral position (the position shown in FIG. 1). ing. At the neutral position, the supply of hydraulic oil from the hydraulic pump 32 to the hydraulic cylinder 30, which is an actuator, is stopped by the spool 26.

A housing 34 is attached to the other opening end (the left end in FIG. 1) of the sliding hole 24 of the valve body 22. A port X is formed in the housing 10 and a port Y is formed in the housing 34 for guiding pilot pressure oil for slidingly operating the spool 26 to both ends of the spool 26.

When pilot pressure oil is supplied to the port X by an operating means (not shown), the spool 26 (in the state shown in FIG. 1) positioned at the neutral position moves the inside of the valve body 22 by the pressure oil. Sliding (to the left in FIG. 1), the spring 8 is compressed while generating a biasing force that is a return force to the neutral position, and the discharge oil of the hydraulic pump 32 flows through the load check valve 36 to the port 38. , Flows into the head side oil chamber 30a of the hydraulic cylinder 30, and extends the hydraulic cylinder 30. The hydraulic oil in the rod-side oil chamber 30b of the hydraulic cylinder 30 is returned to the tank 42 through the port 40 of the valve body 22.

When pilot pressure oil is supplied to the port Y, the spool 26 in the neutral position (state of FIG. 1) is slid inward of the valve body 22 (right side of FIG. 1) by the pressure oil, The spring 8 is compressed while generating an urging force that is a return force to the neutral position, and the oil discharged from the hydraulic pump 32 flows through the load check valve 36 to the port 40 and the hydraulic cylinder 3
0 into the rod side oil chamber 30b, and the hydraulic cylinder 30 is contracted. Head side oil chamber 30 of hydraulic cylinder 30
The hydraulic oil of a passes through the port 38 of the valve body 22 and the tank 42.
Returned to.

When the pilot pressure oil in the port X or the port Y is released, the spool 26 moves to the spring 8 described above.
It is returned to the neutral position by the urging force of. More specific operation of the spring 8 mounting portion will be described later.

The spool detent structure 28 will be described with reference to FIGS. 2 and 3. The rotation stopping structure 28 is attached to a contact surface 44 formed at the end of the spool 26 extending in the direction of the axis 27 and a spacer 46 interposed between the valve body 22 and the housing 10 to prevent rotation of the spool 26. And a spherical body 48 which is an abutting body that abuts against the abutting surface 44 and stops.

The spacer 46 is formed of a plate-shaped steel member and has an insertion hole 46a through which the spool 26 is freely inserted.
And the outer contour is substantially the same as the abutting housing 10 and has two bolt holes 46b. The insertion hole 46a is formed with a recess 46c of a size that holds the sphere 48 freely in a part of the circumferential direction so as to be open to the valve body 22 side and closed to the housing 10 side. In addition, the valve body 22
An annular O-ring seal groove 46d is formed on the mounting surface of and. The spacer 46 has a recess 46c formed by a sintering method.
It is good to mold simultaneously. A steel ball is used as the sphere 48.

The contact surface 44 has a dimension H in the radial direction from the axis 27 of the spool 26 and a dimension K from the end portion in the direction of extension of the axis 27 to the dimension K. It is formed in a plane shape with a gap that allows 48 to freely abut. Dimension K is spool 26
The sphere 48 (FIG. 2) in the neutral position is defined to a length that allows the spool 26 to operate as described above. More specifically, the maximum stroke L (FIG. 2) of the spool 26 defined by the contact between the spring receiver 12 and the spring receiver 14 is twice or more. The stroke L will be described in detail later.

In assembling the spool detent structure 28 formed as described above, first, the spacer 46 and the recess 46 are formed in the valve body 22 in which the spool 26 is incorporated.
A sphere 48 is inserted between the c and the contact surface 44 of the spool 26 and positioned. Next, the spring receivers 12 and 14 and the spring 8 are sandwiched between the spring receivers 12 and 14 at the end of the spool 26, and the spring 16 is attached by the bolt 16. Then, these are covered with the housing 10, and bolts 50 (two) are passed through the spacer 46 and the housing 10 to fix them to the valve body 22.

With reference to FIG. 4 together with FIGS. 1 and 2, the sliding operation of the spool 26 at the portion where the spool detent structure 28 is disposed will be described. When pilot pressure oil is supplied to the port X of the housing 10 by the operating means, the spool 26 moves the valve body 2 as shown in FIG.
Inside the sliding hole 24 of 2, the spring receiver 12 is in contact with the spacer 46, and the spring receiver 14 moves together with the bolt 16 connected to the spool 26, so that the end portions of the spring receivers 12 and 14 are brought into contact with each other. It is pushed in until it abuts (stroke L). At this time, the spherical body 48 of the recess 46 c of the spacer 46 is positioned on the spool end side of the contact surface 44 of the spool 26.

When pilot pressure oil is supplied to the port Y of the other housing 34, the spool 26 contacts the outside of the sliding hole 24 and the spring receiver 14 contacts the inner surface of the housing 10 as shown in FIG. 4B. In the contact state, the spring receiver 12 is pushed and moved by the end portion of the spool 26, and is pushed out until the end portions of the spring receivers 12 and 14 come into contact with each other (stroke L). At this time, the spherical body 48 of the recess 46 c of the spacer 46 is positioned at the farthest position from the spool end side of the contact surface 44 of the spool 26.

The operation of the spool detent structure 28 as described above will be described mainly with reference to FIGS. 2 and 3.

(1) Anti-rotation of the spool: The rotation of the spool 26 in the sliding hole 24 (rotation in the direction shown by the arrow in FIG. 3) is caused by contacting the spherical body 48 whose contact surface 44 is the contact body with the two-dot chain line. It is stopped by abutting as shown in. Therefore, the rotation of the spool 26 is stopped even if a rotational force is generated in the spool 26.

(2) Spherical abutment body: The abutment body that abuts the abutment surface 44 is a spherical surface, which is a sphere 48 in the present embodiment, and the abutment surface 44 extends in the direction of the axis 27 of the spool 26. Since the abutment surface 44 and the sphere 48 are in point contact with each other, the spool detent structure 28 does not become a resistance that hinders the sliding of the spool 26.

Although the present invention has been described in detail above based on the embodiments, the present invention is not limited to the above embodiments, and various modifications are possible within the scope of the present invention, for example, as described below. It can be transformed or modified.

(1) Spool valve: In the present embodiment, the directional control valve 20 is shown as the spool valve, but it goes without saying that the spool valve is not limited to the directional control valve.

(2) Contact surface: In the present embodiment,
The contact surface 44 of the spool 26 extending in the direction of the axis 27 is formed of a flat surface, but as shown in FIG. 5, it may be a circular arc surface 52 having a circular arc cross section and extending in a groove shape.

(3) Contact member: In the present embodiment,
A spherical body 48 is used as an abutting body having a spherical surface. As the abutting body, as shown in FIG.
The plug member 54 provided with 4a may be screwed and attached to the spacer portion 46.

(4) Spacer member: In the present embodiment, the spherical body 48, which is the contact body, is the valve body 22 and the housing 1.
The spacer member 46 is attached to the valve member 22.
It may be attached to itself.

[0031]

According to the present invention, the spool is provided with an abutment surface extending in the axial direction thereof, and the valve body is provided with an abutment body which abuts against the abutment surface and stops the rotation of the spool in the slide hole. Therefore, even if a rotational force is generated on the spool, a rotation stopping structure for the spool is provided that can reliably stop the rotation of the spool.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a directional control valve that is a typical example of a spool valve having a spool detent structure constructed according to the present invention.

FIG. 2 is an enlarged cross-sectional view of a portion of the spool detent structure of FIG.

FIG. 3 is a sectional view taken along the line AA of FIG.

FIG. 4 is a diagram showing the operation of the spool detent structure shown in FIG. 2 depending on the sliding state of the spool. (A) shows a state where the spool is slid inwardly of the valve body. (B) is a state in which the spool is slid to the outside of the valve element.

5 is a view showing another embodiment of the contact surface in the same cross section as FIG. 3. FIG.

FIG. 6 is a view showing another embodiment of the contact body in the same cross section as FIG. 2.

FIG. 7 is a sectional view of a spool end portion of a conventional directional control valve.

[Explanation of symbols]

8: Spring 10: Housing 20: Directional control valve (spool valve) 22: Disc 24: Sliding hole 26: Spool 27: Axis 28: Spool detent structure 44: Contact surface 46: Spacer (spacer member) 48: Sphere (contact body) 52: Arc surface

Claims (6)

[Claims] 1. A structure for preventing rotation of a spool, which is urged by a spring into a sliding hole of a valve body of a spool valve and inserted, the contact surface being formed on the spool so as to extend in the axial direction thereof. And a contact body that is attached to the valve body side and contacts the contact surface to stop rotation of the spool in the sliding hole. 2. The rotation stopping structure for a spool according to claim 1, wherein the contact surface is a flat surface. 3. The spool detent structure according to claim 1, wherein the abutting surface has an arcuate cross section and extends in a groove shape. 4. The detent structure for a spool according to claim 1, wherein the abutting body has a spherical surface that abuts on the abutting surface. 5. The spool detent structure according to claim 4, wherein the contact body is formed of a sphere. 6. The spring is attached to an end of the spool, and a housing for accommodating the spring is attached to an opening end of a sliding hole of the valve body through a spacer member.
6. The spool detent structure according to any one of claims 1 to 5, wherein a corresponding contact body is attached to the spacer member.