JPH03168402A - Actuator for valve drive - Google Patents

Abstract

PURPOSE: To easily and speedily adjust the end of a stroke position by providing a toothed part meshing with a pinion of a shaft connected with a valve member and an end of a stroke contact member adjusting a piston stroke from the outside in a piston having an empty barrel movable in the opposite direction. CONSTITUTION: An empty barrel 3 movable in the opposite direction is provided, and pistons 4, 5 are provided in a first separation chamber 6 and a second separation chamber 7. Toothed parts 20, 21 are provided in connection side parts of the pistons 4, 5 to mesh them with a toothed pinion 22 of a shaft 23. A first core bar 30 which abuts to the piston 4 and can be adjusted from the outside is provided in a head part of the separation chamber 6, a second core bar 36 is mounted in a head part of the separation chamber 7 so as to adjust it from the outside and a cap bush 35 engageable with the head part 38 is provided in the piston 5 to adjust a stroke on the opposite side to the first core bar 30. Consequently, it is possible to adjust a stroke end position easily and speedily, ensure the operation, and reduce cost.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to improvements in actuators for driving valve members.

BACKGROUND OF THE INVENTION As is already known, actuators for opening and closing several valve members usually have either a hydraulic or pneumatic member suitable for driving the drive spindle of the actuated valve member. is commercially available.

These known actuators are generally very complex in construction and do not allow precise adjustment of the rotation angle of the spindle of the valve member according to requirements.

SUMMARY OF THE INVENTION Accordingly, it is a principal object of the present invention to provide an improved valve actuator that allows for easy and quick adjustment of the end of stroke position of a driven valve member. The purpose is to solve the above problems.

(Means for Solving the Problems) In order to achieve the above object, an improved actuator according to the present invention has a body with a cavity in which two pistons can move in opposite directions, and the pistons is provided with a toothed portion that meshes with a toothed pinion fixed to a shaft suitable for connection with the spindle of the valve member to be driven, and is further adjustable from the outside of the main body, and is capable of controlling the opening and closing stroke of the valve member. A stroke abutment member end is provided for contact engagement with the piston don for adjustment.

(Operations and Effects) Therefore, by adjusting the stroke abutting member from the outside of the main body, the end of the stroke position of the bulb member can be adjusted easily and quickly.

(Other objects and effects) Another object of the present invention is to provide a valve actuator that is significantly reduced in size and has a fast response speed so that the valve member can be quickly switched from the closed position to the open position and from the open position to the closed position. Our goal is to provide the following.

Yet another object of the present invention is to provide an actuator that is reliable in operation and can be easily manufactured at low cost from readily available components and materials.

(Example) Improvements of the actuator 1 for driving a valve member according to the present invention will be described with reference to the accompanying drawings. The actuator 1 has a body 2 defining a preferably cylindrical cavity 3. In this cavity 3, two pistons 4.5 move in opposite directions. In other words, the first
and ensure movement in the second compartment 6.7.

A first compressed air discharge duct 10 communicates with the cavity 3, and a further discharge duct 11 communicates with the heads of the compartments 6, 7 for displacing the pistons 4, 5 in opposite directions. ing.

The piston 4.5 is provided with toothed portions 20.21 on its connecting side, these toothed portions extending along a straight line parallel to the piston sliding direction and connected to a shaft rotatably supported on the body 2. It meshes with the toothed pinion 22 fixed to the pinion 23.

As shown in the figure, the shaft 23 protrudes from the main body 2 and has a hollowed-out seat 24 at its bottom so that an accessory 25 can be held therein.
is formed with a corresponding outer hollow for connection with the spindle of the valve member on which the actuator acts.

The fittings 25 are therefore interchangeable for easy and quick engagement with valve spindles of different shapes.

The main feature of the invention is that it is provided with an end of the stroke member which can be directly adjusted from outside the body 2 and into direct contact engagement with the piston.

As clearly shown in FIG. 2, the end of the stroke member is provided with a first mandrel 30 which engages the head of the compartment 6, this threaded mandrel 30 being connected to the first piston. 4 and functions as a contact member when the first piston is displaced in the first direction.

In this regard, it will be clear that when the first piston is locked, the other pistons will also be locked automatically due to the connection between the toothed part and the toothed pinion.

Furthermore, the other piston 5 has a cap bushing 35 which is restrained and engages a second threaded mandrel 36 connected to the other head of the compartment 7, which mandrel has a push end. An enlarged head 38 is provided which abuts and engages an annular reduction 39 formed in the ring.

The head 3 of the second mandrel thus acts as a stop for displacing the piston in a direction opposite to the direction in which the mandrel 30 acts as a stop for the first piston.

Further, the cap bush 35 is fixed to the piston 5,
Preferably, a closing plug is provided in the part of the push facing the toothed pinion.

The adjustment is made by a nut 50, which allows the axles to be properly positioned so that the piston serves as the end of the stroke member. A lock nut 51 is provided on each of the two mandrels.

4 Actuation of the mandrels 30,36 makes it possible to subtly change the position of these mandrels and to stop them precisely in the desired position with complete adjustment of the pistons.

From the above disclosure, it will be clear that the present invention fully achieves its objectives.

Although the invention has been disclosed and described with reference to a preferred embodiment, it will be understood that various modifications may be made without departing from the scope of the appended claims.

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view showing a valve actuator according to the present invention, FIG. 2 is a sectional view taken along the line ■-■ in FIG. 1, and FIG. 3 is a cross-sectional view taken along the line ■-■ in FIG. 1. FIG. 4 is a plan view.

Claims (1)

[Scope of Claims] 1. An actuator for driving a valve, wherein the actuator has a body with a cavity in which two pistons can move in opposite directions, and the pistons move in the direction of the valve member to be driven. The toothed portion is provided with a toothed portion that meshes with a toothed pinion secured to a shaft suitable for connection with the spindle, and further includes a toothed portion that is adjustable from the outside of the main body and is connected to the piston to adjust the opening and closing stroke of the valve member. An actuator characterized in that an end portion of a stroke abutment member is provided for contact engagement. 2. The actuator according to claim 1, wherein the shaft is provided with a seat at one end protruding from the main body to removably receive an attached member connected to the spindle. 3. The actuator of claim 2, wherein said seat has an inner hollow portion that engages a corresponding outer hollow portion of said attachment member. 4. The two pistons define opposing first and second compartments that communicate with a compressed air discharge duct for displacing the pistons in the cavity. actuator. 5. The stroke abutting member end portion is a mandrel rotatably supported on the heads of opposing first and second compartments formed in the cavity. actuator. 6. The actuator further comprises a first threaded mandrel rotatably supported in the head of the first compartment and adapted for contacting engagement with a first piston. Actuator as described. 7. The actuator further comprises a cap bushing on the second piston having an inner seat therein that engages a head of a second threaded mandrel rotatably supported on the head of the second compartment. and further configured to act as an abutment member for the head to form a stroke position end of the second piston in a piston sliding direction opposite to a sliding direction of the first piston in contact with the first mandrel. 2. The actuator according to claim 1, further comprising an annular abutting member having a circular shape. 8. The actuator further includes an adjustment bolt that engages the mandrel for fine adjustment of the mandrel, and further includes a lock nut for holding the mandrel in a set position. The actuator according to claim 1.