JPS616405A - Reciprocating apparatus - Google Patents

Abstract

PURPOSE:To simplify the structure and to reduce the cost by disposing two switch valves in fluid passages leading to an actuator in such a manner as to opposite to each other, and switching the switch valves alternately by means of a lever mounted on an output shaft of the actuator. CONSTITUTION:Two switch valves 10, 11 are disposed in fluid passages 7, 8 leading to an atuator 11 in such a manner as to be opposite to each other, and a lever 5 is fixed to an output shaft 4 of the actuator 1. The switch valves 10, 11 are switched alternately by the leaver 5. In this arrangement, the actuator 1 can be reciprocated by using the existing fluid pressure system for reciprocating the actuator, so that the structure can be simplified to reduce the cost.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a reciprocating device that generates reciprocating motion using fluid.

(Prior Art) A reciprocating device is used, for example, as a drive source for a metering pump, and provides reciprocating motion to the metering pump. Conventionally, this type of reciprocating device generally uses a reciprocating actuator (cylinder), and its direction is changed by an electric or pneumatic limit switch attached to the locus of movement of the output shaft of the actuator. I was going. In addition, a separate deceleration device is generally provided to decelerate the operation of the actuator at the turnaround point to ensure stability in direction change.

(Problem to be solved by the invention) However, in the above direction change method, the limit switch,
Reciprocating devices require accessory devices such as relay circuits and speed reduction devices, and the reciprocating device as a whole has a complicated structure, requires troublesome maintenance, and is inevitably expensive.

The present invention aims to solve the above problems and provide a reciprocating device with a simple structure and low cost.

(Means for Solving the Problems) Therefore, the present invention provides an actuator that reciprocates with fluid, a fluid pressure source that supplies fluid to the actuator, and an output shaft of the actuator that is connected to the fluid pressure source. The present invention has realized a reciprocating device including two switching valves that are provided opposite to each other in the moving direction of the actuator so as to be able to alternately abut and separate from each other to switch the fluid flow path to the actuator.

(Function) In the above-mentioned reciprocating device, fluid is supplied to the actuator through one switching valve that is always open at first, the output shaft of the actuator moves forward, and the other switching valve that is normally closed is switched near the turning point. Abuts against the valve. Finally, the other switching valve opens, and at the same time, the - switching valve closes due to the difference in the effective area of the spools, the fluid flow path to the actuator is switched, and the output shaft of the actuator moves backward. After that, the actuator automatically reciprocates.

(Embodiments) Hereinafter, embodiments of the present invention will be described based on the accompanying drawings.

FIG. 1 shows the system of the reciprocating device according to the present invention. In the same figure, l is an actuator, which includes a cylinder 2, a piston 3 that is slidably installed inside the cylinder 2, a piston rod 4 that extends from the piston 3 to the outside through the cylinder l, and A lever 5 is fixedly installed perpendicularly to the tip of the piston rod 4.

It consists of Inside the cylinder 2, two chambers 6a and 6b are defined by the piston 3, and the respective chambers 6a and 6b are defined by a piston 3.
A fluid at a predetermined pressure is supplied to b from a fluid pressure source 9 through a first pipe 7 and a second pipe 8 of separate series.

10 is a first switching valve installed in the first pipe 7; 11 is a second switching valve installed in the second pipe 8; both of them face each other so as to be able to abut against the lever 5. It is arranged as follows.

The first and second switching valves 10.11 are connected to the cylinder 1, respectively.
2a, 12b, spools 13a, +3b slidably installed inside the cylinders 12a, +2b, and the spool 1.
Insert cylinders 12a and +2b from 3a and 13b to A
The valve stems 14a, 14b are provided with valve stems 14a, 14b extending up to the 1st part, so that the valve stems 14a, 14b can come into contact with the above-mentioned/he-5. The spool 13a of the second switching valve 10 is normally biased in the valve opening direction, and the spool 13b of the second switching valve 11 is biased in the valve closing direction when the switching valve 10 is in operation.

Further, from the middle of the first pipe 7, a second switching block 1'1
A first branch pipe 16 that communicates with the side opposite to the valve rod in the second pipe 8 is extended, while a first switching valve 10 is connected from the middle of the second pipe 8.
A second branch pipe 17 is extended to communicate with the side opposite to the valve rod. Further, a first discharge pipe 19 equipped with a first throttle 18 constituting a deceleration means, which will be described later, extends from the middle of the first branch pipe 16, and a first discharge pipe 19 is provided with a first throttle 18 that constitutes a deceleration means, which will be described later. A second discharge pipe 21 is provided with a second throttle 20, which also serves as a speed reduction means. That is, the secondary side of the first switching valve 10 communicates with the rear end of the second switching valve 11 and the first throttle 18, while the secondary side of the second switching valve 11
The next side communicates with the rear end of the first 9J switching valve 10 and the second throttle 20.

In addition, the discharge pipe 2 is also connected to PfSl and the second switching valve 10.11.
2 are attached to each. Also, the spools 13a, 1
3b is set to have a smaller effective cross-sectional area than the piston 3 of the actuator 1.

With the configuration shown above, when the fluid pressure source 9 is activated now, the switching valve 11 of the first node 2 is closed, so the first switching valve 1 is closed.
Fluid is supplied to one chamber 6a in the actuator 1 through the first pipe 7 and the first pipe 7, thereby causing the piston 2 and therefore the piston rod 4 to move forward to the right. During this time, the fluid that was present in the other chamber 6b in the actuator l is
It reaches the second switching valve 11 through the pipe 8°, and is discharged to the outside via the discharge pipe 22 there.

As the piston rod 4 moves forward, the piston rod 4-5 comes into contact with the valve stem 14b of the second switching valve 11, as shown in FIG. The spool 13b eventually closes the flow path of the second pipe 8 leading to the discharge pipe 22, and the second
It becomes impossible to discharge fluid from the switching valve 11. During this time, the movement of the piston 2 is decelerated.

When the lever 5 moves further forward, as shown in FIG. 3, the flow path of the second pipe 8 leading to the fluid pressure s9 is opened, and the fluid is supplied to the chamber 6b in the actuator l through the second pipe 8. Ru. On the other hand, the fluid pressure at that time is guided to the rear end of the first switching valve 10 via the second branch pipe 17, and the piston 2
Due to which effective area difference, the spool 13a therein advances against the biasing force of the biasing means 15a as shown, closing the first pipe 7 leading to the fluid pressure source 9 and opening the discharge pipe 22.

This ensures the movement of the fluid in the chamber 6a of the actuator 1, the piston 2 is changed direction and retreats to the left, and the lever 5 is again moved to the valve stem 1 of the first switching valve 10.
4a, and finally the first pipe 7 leading to the discharge pipe 22 is closed due to the retreat of the spool 13a.

As a result, the fluid in the chamber 6a of the actuator 1 is discharged through the first throttle 18, and the movement of the piston 2 is decelerated at this stage. Finally, the actuator 1 returns to the original state shown in FIG. 1, and thereafter repeats the above operation.

Note that even if the fluid pressure source 9 is stopped during the operation of the actuator, the biasing force of the biasing means 14a and 14b will cause the first,
The second switching valve 10.11 returns to its old position (7m in FIG. 1).

(Effects of the Invention) As described above in detail, the reciprocating device according to the present invention includes two switching valves facing each other in the fluid flow path to the actuator, and the output shaft of the actuator is connected to the The fluid flow path is switched by alternately contacting the switching valve, making it possible to switch the actuator operation using the existing fluid pressure system that reciprocates the actuator. This reciprocating device has an overall structure that is as simple as possible, and has the effect of being able to be realized at a low cost.

[Brief explanation of the drawing]

FIG. 1 is a system diagram of a reciprocating device according to the present invention, and FIGS. 2 and 3 are explanatory diagrams showing how the reciprocating device is used. ■...Actuator, 4...Output shaft 5...Lever, 7, 8...Piping 9...Fluid pressure source
, 10...first switching valve 11-'fs 2 (
7) Switching valve, 13a, 13b...spool 14a,
+4b... Valve stem', +5a, 15b... First means 16.17... Branch pipe, 18.20... Restriction 19.21... υ1 outlet pipe patent applicant Tokico Co., Ltd. agent Person Yumi Calyx (and 1 other person) Figure 1 Figure 2

Claims (5)

[Claims] (1) An actuator that reciprocates with a fluid, a fluid pressure source that supplies fluid to the actuator, and a fluid pressure source that is connected to the fluid pressure source and that alternately contacts and separates from the output shaft of the actuator. A reciprocating device comprising: two switching valves provided opposite to each other in the moving direction of the actuator to switch a fluid flow path. (2) The reciprocating device according to claim 1, wherein a lever that can come into contact with the switching valve is attached to the output shaft of the actuator. (3) The switching valve is composed of a spool valve, and includes a valve stem that can come into contact with the output shaft of the actuator and a biasing means that normally biases the spool toward the valve opening side or the valve closing side. A reciprocating device according to claim 1. (4) The reciprocating device according to claim 1 or 3, wherein the secondary side of one switching valve and the opposite valve stem side of the other switching valve are in communication with each other. . (5) A deceleration means is connected to the side opposite to the valve rod of the switching valve to reduce the operation of the actuator by squeezing and discharging the fluid during the switching operation. Reciprocating device.