JPH11248013A - Linear valve - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To convert a rotation input into a linear output and control a flow rate with a small operation force. A cam mechanism is formed by fitting steel balls (9a, 9b) into semicircular grooves (14a, 14b) provided on the opposite end face of the input shaft (1) and having a groove depth shallower in the rotation direction. With this cam mechanism, the rotation of the input shaft activates the slide 3 having a flow control unit movable in the output axis direction, and the rotation of the input shaft 1 is converted into the linear movement of the slide 3 in the axial direction. Control.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear valve for controlling a flow rate according to a rotation input amount.

[0002]

2. Description of the Related Art A conventional rotary input type flow control valve of this type is of a rotary valve type for controlling a flow path by rotating a spool, and its structure is as shown in a sectional view of FIG. That is, the configuration is such that a cylindrical sleeve 52 having two through holes 51a and 51b in a direction perpendicular to the axis is fitted to the inner diameter of the sleeve and is rotatable with respect to the sleeve. A spool 54 having a through hole 53 in a direction perpendicular to the axis communicating with the holes 51a and 51b
And the two through-holes 51 which are fitted externally to the sleeve 52.
a, an external connection port 55 communicating with each of
a, 55b, and rotation support bearings 57, 5
8 are provided.

When the spool 54 is rotated by an external rotational force, the passage 53 is formed in the holes 51a and 51b of the sleeve.
And a flow path from one port 55a of the case to the other port 55b is formed, and the opening area formed by the holes 51a and 51b of the sleeve and the hole 53 of the spool is changed by changing the rotation angle of the spool. And thereby controls the flow rate through said flow path.

[0004]

However, in the conventional rotary valve, if an attempt is made to reduce the internal leakage between the spool and the sleeve, the frictional resistance increases in order to reduce the gap, and a large operating force is required. There are problems that the size and weight are larger than those of the valve system, and that the cost is increased due to selection of a material having good wear resistance and special wear resistance treatment. The present invention
In order to take advantage of the linear valve in view of such problems, using a mechanism that converts the rotation input to valve linear displacement,
It is an object of the present invention to provide a linear valve with reduced rotational operation force.

[0005]

In order to achieve the above object, a linear valve according to the present invention comprises a rotatable input shaft and a cam mechanism using a steel ball as a cam follower to rotate the input shaft in the direction of the input shaft. The opening degree of the flow path is controlled by a conversion mechanism that converts the linear motion into a linear motion and an output shaft that performs the linear motion after the conversion. Therefore, the linear operation of the valve can be smoothly performed by the steel ball.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will now be described with reference to FIGS.
This will be described with reference to FIG.

FIG. 1 is a sectional view showing the structure of a linear valve according to the present invention. This linear valve is a motion conversion unit that converts external rotation input into linear motion by a cam mechanism using a steel ball as a cam follower, a flow control unit that controls the flow rate by linear motion, and a casing unit that has a connection port that connects to an external actuator. It is composed of

[0008] First, the motion converter has a disk-shaped end, and a phase 180 ° coaxial with the center axis of the disk on the non-input side end face 12 of the disk.
The radial bearing 7 is formed by engraving two semicircular concave grooves 14a and 14b of a cross section (see FIG. 4 showing a cross section taken along the line CC in FIG. 3) which is shifted and whose bottom depth gradually decreases in the circumferential direction. The input shaft 1 supported by the shaft 8 and the thrust bearing 8;
Steel balls 9a and 9b guided by 4b, and irregularities fitted into axial slits 13 provided in housing 6 on the outer periphery for supporting the steel balls so that they can rotate and cannot revolve around the axis of input shaft 1. Ball retainer 2 with
(See FIG. 2) and a recess 1 holding steel balls 9a, 9b at positions corresponding to the grooves 14a, 14b at one end.
A slide 3 having a disk-shaped end surface having irregularities fitted on an outer circumferential surface of the housing 6 and engraved with 6a and 16b, and a spring 10 for urging the slide 3 toward the input shaft; It is composed of That is, the motion conversion unit is mainly a cam mechanism using a steel ball as a cam follower. And the slide 3 corresponds to the output shaft.

The flow rate control section includes a cylindrical portion extending on the side opposite to the input shaft of the slide 3, that is, the slide 3, which has a groove 17 on the outer periphery, and a through hole 18a, 1
8b and a cylindrical sleeve 4 having a hole 8b.
The slide 3 corresponds to the output shaft, but is formed integrally with the valve body in the illustrated example.

[0010] The casing part is a through hole 1 of the sleeve 4.
Body 5 having external connection ports 20 and 21 communicating with 8a and 18b, and one support bearing 11 of the slide 3
And a cover 19 having the same.

The other support bearing 24 of the slide 3 is provided at the center of the end surface 12 of the input shaft 1 on the side opposite to the input shaft.

Normally, the outer peripheral groove 17 of the slide 3 does not communicate with the through holes 18a and 18b of the sleeve 4,
It is shut off between 0 and 21.

When a rotational force is applied to the input shaft 1, the grooves 14a, 14b formed on the disk-shaped end face 12 and having shallow bottoms in the circumferential direction revolve. On the other hand, since the steel balls 9a and 9b fitted in the grooves cannot revolve in the circumferential direction by the ball retainer 2, the steel balls 9a and 9b rotate on their own and move relatively to the shallower grooves 14a and 14b with the rotation of the input shaft.
Is reciprocated in the sleeve 4 side. As shown in FIG. 5, when the slide 3 is moved, the groove 17 provided on the outer periphery of the slide 3 communicates with the through holes 18a and 18b of the sleeve 4, and the external connection ports 20 and 21 communicate. By changing the rotation angle of the input shaft 1, the amount of axial movement of the slide 3 is controlled, and the opening area to the through holes 18a, 18b is changed to control the flow rate between the external connection ports 20, 21. Also, grooves 14 a, 1, which are formed in the end face 12 of the input shaft 1.
By changing the curve of the bottom surface shape of 4b, it is possible to provide a dead zone for the rotation input and change the flow control pattern for the left and right rotation.

[0014]

As described above, the present invention is constructed as described above. When converting a rotary input into a linear motion, the frictional force can be reduced and the flow rate can be controlled with a small operating force. Further, since only the necessary rotation angle can be slid, that is, the valve can be linearly stroked, the overall length can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a configuration of a linear valve of the present invention.

FIG. 2 is a diagram showing a cross section taken along line AA of FIG. 1;

FIG. 3 is a diagram showing a BB cross section of FIG. 1;

FIG. 4 is a view showing a cross section taken along line CC of FIG. 3;

FIG. 5 is a diagram in which a slide is moved in a linear direction by rotating an input shaft.

FIG. 6 is a sectional view showing a configuration of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Input shaft 2 ... Ball retainer 3 ... Slide 4 ... Sleeve 5 ... Body 6 ... Housing 7 ... Radial bearing 8 ... Thrust bearing 10 ... Spring 11 ... Bearing 19 ... Cover 22 ... Groove bottom

Claims (1)

[Claims] 1. A conversion mechanism for converting a rotary motion of an input shaft into a linear motion in an input axis direction by a rotatable input shaft and a cam mechanism using a steel ball as a cam follower, and an output shaft which is converted and linearly moves. A linear valve characterized by controlling the degree of opening of a flow path.