JPS63266287A - Valve opening/closing apparatus - Google Patents

Abstract

PURPOSE:To smoothly actuate a valve by contacting slidably each other the peripheral surface of a scotch yoke to the base of a U-shaped groove formed in the piston tail of a piston. CONSTITUTION:A body has a scotch yoke 15 fixed to two pistons 12, piston tails 13 and an output shaft 11, and engaged with pins 14. A groove 20 having a U-shaped cross-section is formed on each piston tail 13 and the outer peripheral surface of the scotch yoke 15 is brought into contact with the base of the groove 20 slidably each other so as to maintain the posture of the piston 12 during its reciprocation. Accordingly, even if the piston 12 rotates about the axial center, the sliding resistance shows no more increase, because the contact width between the outer peripheral surface of the scotch yoke 15 and the base 20 of the piston tail 13 is narrow.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a pneumatically operated valve opening/closing device that rotates a valve shaft, and more specifically, a piston is reciprocated to rotate a Scotch choke.

This invention relates to an improvement of a valve opening/closing device that can obtain large torque at the beginning and end of valve opening/closing.

[Prior Art] As shown in FIGS. 5 and 6, a conventional valve opening/closing device that rotates a Scotch choke using a piston has a cylindrical main body 10 and a cylindrical main body 10 that is supported by a bearing at the center of the main body and is perpendicular to the axis. an output shaft 11 protruding in the direction, left and right pistons 12 arranged symmetrically with respect to the output shaft 11 on both sides of the output shaft 11 of the main body lO, and an inner surface of the main body so as to sandwich the output shaft from the left and right pistons 12. a piston tail 13 extending along the piston tail 13; a pin 14 implanted in the piston tail 13 in parallel with the output shaft 11;
4, and the left and right side plates 16 of the main body 10. When pressurized air is introduced inside the piston 12, the piston 12 moves outward and the Scotch choke 15, that is, the output shaft 11, is moved to one side. When the valve rotates and the valve closes and pressurized air is introduced to the outside of the piston 12, the piston 1
2 moves inward to open the valve. piston 12
The posture during reciprocation is maintained by inserting the piston tail 13 between the output shaft 11 and the inner surface of the main body 10, and the piston tail 1
There is a resin sleeve 1 on the circumferential surface of the output shaft 11 that slides on the output shaft 11.
9 was fitted externally.

[Problems to be Solved by the Invention] In the conventional device, the piston tail 13 of the piston 12 is guided by sliding bearings 19 fitted on both sides of the Scotch choke 15 of the output shaft 11. If the piston tail 13 rotates even slightly relative to the center, one side of the piston tail 13 will be inclined to sink into the sleeve 18, resulting in a significant increase in contact resistance. Therefore, there was a problem in that the pressure of the pressurized air that operates the piston 12 had to be set high.

If the valve is closed by pushing the piston 12 with a spring when the pressure air is released, the spring is housed between the inner surface of the side plate and the outer surface of the piston, but in order to reduce the axial protrusion length of the side plate. However, if the piston tail 13 is guided by the output shaft 11 as shown in FIG. Piston tails 1 of mutually opposite pistons in the inner central part of
Since the tip of the piston 12 was not able to be recessed inward. As a result, there was a problem in that accommodating the spring considerably increased the length of the device in the axial direction.

The present invention was made to solve the above problem, and its purpose is to enable smooth operation without increasing the pressure of pressurized air, and to enable smooth operation of the valve by closing or opening the valve. To provide a valve opening/closing device whose axial length does not become so large when a spring is attached thereto.

[Means for Solving the Problems] In order to achieve the above object, the features of the present invention include the following:
As shown in FIG. 1, the piston tail 1 of the piston 12
3 is formed with a groove having a U-shaped cross section, and the outer circumferential surface of the Scotch choke 15 is slidably abutted against the bottom surface of the groove, thereby maintaining the posture of the piston 12 during reciprocation.

[Function] When pressurized air is introduced inside the piston 12, the piston 12 moves outward and rotates the output shaft 11 in one direction to open the valve. When pressurized air is introduced outside, the piston 12 moves inward. The valve is closed, but at this time the piston tail 13 of the piston 12 is restrained between the outer peripheral surface of the Scotch choke 15 and the inner surface of the main body 10 and reciprocates, so that the piston 1
2 maintains a posture orthogonal to the axis J direction and moves smoothly.

Even if the piston 12 rotates slightly around its axis during reciprocation, the outer peripheral surface of the Scotch choke 15 and the piston tail 13
Since the contact width of the bottom surface of the groove 20 is relatively narrow, the sliding resistance of the piston does not become particularly large.

When the pistons 12 on both sides move inward, the tip of the other piston tail 13 comes to the inner peripheral edge of the piston 12, so as shown in FIG. It becomes possible to fit. Therefore, even if the valve is closed by the spring 17 when the pressurized air is released, the length of the device in the axial direction does not become very large.

[Example] The apparatus of the present invention will be described in more detail based on an example shown in the drawings. As shown in Figures 1 to 3, the device includes a cylindrical main body 10, an output shaft 11 that is supported in the center of the main body and protrudes in a direction perpendicular to the axis, and is symmetrical about the output shaft. Left and right pistons 12 are fitted on both sides of the main body 10.

A piston tail 13 extends from the piston along the inner surface of the main body lO so as to sandwich the output shaft 11, a bin 14 rotatably supported by the piston tail, and an output shaft 1
Scotch choke 15 fixed to 1 and engaged with pin 14
and a side plate 1B that covers the left and right end faces of the main body 10.

The main body 10 is provided with pressure air introduction holes 31 and 32 that open to the outside and inside of the piston 12. Although not shown, the protruding end of the output shaft 11 is connected to the operating shaft of the valve via a coupling or the like. Concatenated.

As shown in FIG. 2, the piston tail 13 has a U-shaped cross section and has a groove 20 extending in the axial direction.

The arcuate outer circumferential surface 21 of the Scotch choke 15 is in contact with the bottom surface of the groove 20, and the pin 14 crosses the groove 20 at right angles to the Scotch choke 1.
It fits into the pin groove 22 of No.5.

As shown in FIG. 1, when the left and right pistons 12 move inward, the piston tails 13 of each other come into contact with the inside of the piston 12, but since the contact portion is the peripheral edge, the piston 12 is moved inward. It can be recessed to form a spring receiver 30 on the outside.

As shown in FIG. 2, the output shaft 11 has a piston tail 13
There is no need to attach a sleeve or the like to the output shaft 11 to prevent wear.

When pressurized air is introduced into the piston 12 through the introduction hole 32, the left and right pistons 12 move outward, and the pistons 12 move outward. 4 rotates the output shaft 11 in one direction via the Scotch choke 15, the valve opens, and when it enters the outside of the piston 12 from the introduction hole 31, the left and right pistons 12 move inward, and the bottle 1
4 reverses the output shaft 11 via the Scotch choke 15, so the valve closes. At this time, the piston tail 13 of the piston 12 is sandwiched and guided between the outer peripheral surface 21 of the Scotch choke 15 and the inner peripheral surface of the main body 10. piston 12
However, even if it rotates slightly around the axis during reciprocation, the sliding resistance of the piston 12 will not become particularly large because the width of the outer peripheral surface of the Scotch choke 15 in contact with v420 of the piston tail 13 is relatively small. Therefore, even if the pressurized air is set at a relatively low pressure, the piston 12 operates smoothly.

As shown in FIG. 4, when the left and right side plates 16 of the main body 10 are made into a bowl shape and accommodate the coil spring 17 which can be adjusted with a port 27 and a washer 28, when the pressure air from the introduction hole 32 is released, the piston 12 can be automatically moved inward by the force of spring 17 to close the valve. That is, when the pressure inside the piston 12 decreases.

The spring 17 pushes the piston 12 inward and rotates the output shaft 11 integral with the Scotch choke 15 via the pin 14 of the piston tail 13. Since the outer surface of the piston 12 is recessed inward to form the spring receiver 30, the provision of the spring 17 does not significantly increase the length of the device in the axial direction.

[Effects of the Invention] As described above, unlike the conventional device in which the piston tail of the piston is guided along the output shaft, the piston tail of the piston is guided by the outer peripheral surface of the Scotch choke, so that the piston tail of the piston is guided by the outer circumferential surface of the Scotch choke. Even if the piston rotates slightly around its axis, the sliding resistance of the piston does not become particularly large.Therefore, an excellent effect is obtained in that the pressure of the working fluid can be lowered than before. It will be done.

Further, when the left and right pistons are brought together, the piston tails touch the peripheral edges of the opposing pistons, so the pistons can be recessed inward to form a spring receiver on the outside. Therefore, even when a spring is provided, the device of the present invention provides a special effect in that the length in the axial direction does not become so large.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of an apparatus according to an embodiment of the present invention, showing a state in which the piston is moved inward. FIG. 2 is a cross-sectional view of the device of FIG. 1, showing the piston in an intermediate position. FIG. 3 is a longitudinal sectional view showing a state in which the piston is moved outward. FIG. 4 is an exploded perspective view of another embodiment. FIGS. 5 and 6 are views corresponding to FIGS. 1 and 2 of the conventional apparatus. In the figure, 10 is the main body, 11 is the output shaft, 12 is the piston, 13 is the piston tail, 14 is the bottle, 15 is the Scotch choke, 16 is the side plate, 17 is the spring, 20 is the groove, 2
Reference numeral 1 indicates an outer circumferential surface, 22 indicates a pin groove, and 30 indicates a spring receiver.

Claims (1)

[Scope of Claims] 1) A cylindrical main body, an output shaft supported at the center of the main body and protruding in a direction perpendicular to the axis, and slidable on the main body symmetrically about the output shaft. two pistons fitted into the body, and a piston tail extending axially along the inner surface of the main body so as to sandwich the output shaft from the two pistons to form a groove having a U-shaped cross section; A Scotch yoke fixed to the center of the output shaft and fitted into the U-shaped groove of the piston tail, a pin attached to the piston tail and engaged with a pin groove of the Scotch yoke, and a pin provided on the left and right end surfaces of the main body. and a pressure air introduction hole opening on the inside and outside of the piston, the apparatus comprising: a side plate having a side plate formed on the piston; and pressure air introduction holes opening on the inside and outside of the piston, the apparatus comprising: A valve opening/closing device characterized in that the piston tail is sandwiched and guided between the inner surface of the main body and the outer peripheral surface of the Scotch yoke. 2) The tip of the piston tail is formed so as to come into contact with the inner peripheral edge of the other piston when the pistons move inward, and the outer surface of the piston other than the peripheral edge is recessed inward to form a spring receiver. A valve opening/closing device according to claim 1, characterized in that: