JPH0584835B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a reciprocating motion switching device used in a pump that reciprocates by automatically switching fluid pressure.

(Prior art) As shown in Japanese Unexamined Patent Application Publication No. 64-369, a switching valve chamber provided inside a switching device main body, and a valve inserted through the switching valve chamber alternately supplying and discharging fluid to two working fluid chambers. an actuating rod that is reciprocated by a working fluid; a switching body that is loosely fitted in the actuating rod in the axial direction and is moved to one side or the other side of the switching valve chamber; A concave switching element that switches the supply and discharge of working fluid supplied to the switching valve chambers to and from the two working fluid chambers, and a spring that holds the switching body on one side or the other side of the switching valve chamber. In a reciprocating switching device for a pump having
As the spring, a substantially C-shaped wire spring is formed by bending both ends of a wire in opposite directions, and the straight portions at both ends of the wire spring are perforated in the lateral direction of the switching body. The wire spring is rotatably fitted into the provided hole, and the central linear part of the wire spring is integrated into the inner surface of the plug, which is located on the opposite side of the switching element and closes the switching valve chamber. There is something that is attached to the body so that it can rotate freely.

(Problems to be Solved by the Invention) In this conventional example, the switching actuating body, which is a relatively large member, is snap-actioned by a wire spring with respect to the spring receiver provided on the plug. The protrusion of this wire spring also increases, making it impossible to form the switching device main body, switching valve chamber, etc. compactly (small diameter). It is also necessary to separately provide a detent spring for holding the switching element in the switching position and bringing it into close contact with the opposing switching valve seat.

SUMMARY OF THE INVENTION An object of the present invention is to provide a reciprocating switching device in which wire springs can be incorporated more compactly than in conventional devices, and the number of parts is even smaller than in conventional devices.

[Structure of the invention]

(Means for Solving the Problems) The present invention includes a switching valve chamber 22 provided inside a switching device main body 11, and two working fluid chambers 18 and 19 that are inserted through the switching valve chamber 22 and are alternately supplied and discharged. The actuating rod 13 is reciprocated by the actuating fluid.
A switching actuating body 23 is loosely fitted in the actuating rod 13 in the axial direction and is moved to one side or the other side of the switching valve chamber 22, and the switching actuating body 23 operates to switch and supply the switching valve chamber 22. a relatively small and lightweight switching element 27 that switches the supply and discharge of the working fluid to and from the two working fluid chambers 18 and 19;
3 and a spring holding the switching valve chamber 22 on one side or the other side, the spring has both sides curved with respect to a straight portion 71 located at the center of the wire. A substantially C-shaped wire spring 64 is formed by arranging the linear portions 72 located at both ends to face each other, and the linear portion 71 at the center of this wire spring 64 is connected to the switching element 27 and the switching actuating body 23. The linear portions 72 at both ends of the wire spring 64 are rotatably fitted to the other of the switch 27 and the switching body 23.

(Function) In the present invention, as the actuating rod 13 moves, the switching actuating body 23 is also moved, and until the spring fitting part of the switching actuating body 23 is lined up with the spring fitting part of the switching element 27, the switching actuating body 23 is moved. The wire spring 64 between the switching actuating body 23 and the switching element 27 is compressed while rotating around the spring fitting part of the switching element 27, and the spring fitting part of the switching actuating element 23 is compressed by the switching element 27. If the wire spring 64 passes even slightly past the spring fitting part, the restoring force stored in the wire spring 64 is applied to the small and lightweight switching element 27, and this switching element 27 instantly locks on the opposite side within its loose fitting range. position and the working fluid chambers 18, 19
The supply and discharge of working fluid to and from the pump can be switched in an instant.

(Examples) Hereinafter, the present invention will be described in detail with reference to examples shown in the drawings.

As shown in FIG. 1, a cylinder 12 is hermetically screwed onto the upper side of the switching device main body 11, and an actuating rod 13 is movably fitted into the center of the switching device main body 11. A washer 14 and a cap nut 15 are screwed together at the upper end, and a piston 17 consisting of a pair of disks 16 and a packing is clamped by these.
8 and a lower working fluid chamber 19 are provided.

An air supply port 21 through which compressed air is supplied is provided on the side surface of the switching device main body 11, and this air supply port 21 communicates with a switching valve chamber 22 formed approximately at the center of the switching device main body 11. Inside this switching valve chamber 22, a switching actuating body 23 is loosely fitted in the axial direction within a predetermined range to the actuating rod 13, and is slid relative to the rod 13. A flat portion 24 is formed on one side of the switching body 23 . A guide plate 25 is fitted into the device main body 11 so as to face the flat portion 24 of the switching body 23, and a switch 27 is fitted into the guide square hole 26 so as to be movable in the axial direction. A recess 28 is formed in the sliding surface of the switch 27. This switching element 27 is formed to be relatively small and lightweight compared to the switching operating body 23.

A portion of the switching element 27 facing the sliding surface includes:
The switching valve seat 31 is highly wear resistant like the switching element 27.
is fitted, and an air supply hole 32, an exhaust hole 33, and an air supply hole 34 are bored in this switching valve seat 31. Each of the holes 32, 33, and 34 communicates with an air supply hole 35, an exhaust hole 36, and an air supply hole 37 formed in the main body 11 of the switching device.
It communicates with a connection port 38 provided in the. A pipe 43 is communicated with this connection port 38 via an elbow 41 and a pipe fitting 42, and a connection port 46 of the cylinder 12 is further communicated with this connection port 38 via a pipe fitting 44 and an elbow 45.

The actuating rod 13 has a bush 51 fitted on the upper side of the switching actuating body 23 and a large diameter portion 52 formed on the lower side. A gland housing 54 is fitted to the bush 51 via an O-ring 53, and a packing 55 is fitted to the large diameter portion 52.
are fitted.

A large diameter screw hole 61 is provided on the left side of the switching valve chamber 22.
A plug 62 is screwed into this screw hole 61 with an O-ring 63 interposed therebetween. In the switching valve chamber 22 sealed by the plug 62, a wire spring 64 formed of a wire rod (piano wire) with a round cross section is interposed between the switching element 27 and the switching actuating body 23. ing.

As shown in FIG. 2, this wire spring 64 has a linear portion 71 formed in the center, and linear portions 72 at both ends face each other with respect to the central linear portion 71. By curving both sides, it is formed into an approximately C shape. The straight portion 71 at the center of the wire spring 64 is rotatably fitted into the groove 73 of the switch 27 based on the round cross section, and the straight portions 72 at both ends of the wire spring 64 are It is rotatably fitted into a hole 74 bored in the switching body 23.

A reciprocating pump (not shown) is integrally provided on the lower side of the switching device main body 11, and the operating rod 1
It is driven by the reciprocating motion of 3.

Next, to explain the operation of this embodiment, the pressurized air supplied from the air supply port 21 to the switching valve chamber 22 is
The air inside the working fluid chamber 19 is sent to the working fluid chamber 18 through the air supply holes 34, 37, the connection port 38, the pipe 43, etc., and the piston 17 is moved downward by the internal pressure of this chamber 18, and the internal air of the working fluid chamber 19 is sent to the working fluid chamber 18 through the air supply holes 34, 37, the connection port 38, the pipe 43, etc. , are pushed out through the recess 28 of the switch 27 and the exhaust holes 33, 36.

When the downward movement of the actuating rod 13 approaches its end, the switching actuating body 23 is moved by the bush 51.
is moved downward, and the wire spring 64 is rotated downward about the central linear portion 71, until the linear portions 72 at both ends are aligned horizontally with the central linear portion 71. The shaped part 72 receives a compressive force in the direction of approaching the central straight part 71,
Elastic force is stored inside this spring 64. When the linear portions 72 at both ends move below the central linear portion 71, the repulsive force stored in the wire spring 64 is instantaneously applied to the small and lightweight switch 27, causing the wire spring to move downward. 64 is reversed upward using the linear portions 72 at both ends as fulcrums, and the switch 27 is instantly moved upward, and the exhaust hole 33 and the air supply hole 34 are communicated through the recess 28 of the switch 27. , the switching valve chamber 22 to which pressurized air is supplied is communicated with the air supply hole 32.

As a result, compressed air is supplied from the switching valve chamber 22 to the working fluid chamber 19 via the air supply hole 35, the piston 17 is moved upward, and the air pushed out from the working fluid chamber 18 is transferred to the pipe 43, the air supply holes 37, 34 , recess 28 of switched switch 27, exhaust holes 33, 36
It is then discharged to the outside.

When the upward movement of the actuating rod 13 approaches its limit, the large-diameter portion 52 engages with the switching actuating body 23, and together with the actuating rod 13, this switching actuating body 2
3 also moves upward, and along with this movement, the wire spring 64 rotates upward using the central linear portion 71 as a fulcrum, until the linear portions 72 at both ends are aligned horizontally with the central linear portion 71. A compressive force is stored in the wire spring 64. Then, when the linear portions 72 at both ends move above the central linear portion 71, the restoring force stored in the wire spring 64 is instantaneously applied to the small and lightweight switch 27.
The switch 27 is momentarily switched downward.

Such operations are repeated, and the reciprocating motion for driving the pump continues.

In addition, in the above embodiment, the wire spring 64
The central linear portion 71 of the switch 27 is connected to the groove 7 of the switch 27.
3, and the linear portions 72 at both ends of the wire spring 64 connect to the switching actuating body 23.
Although it is rotatably fitted into the hole 74, this relationship may be reversed. That is, the wire spring 6
4 is rotatably fitted into the groove provided in the switching body 23, and
Straight portions 72 at both ends of this wire spring 64
may be rotatably fitted into a hole provided in the switch 27.

〔Effect of the invention〕

According to the present invention, since the wire spring is provided so as to snap-action the switching element, which is a relatively small member, with respect to the switching actuating body, the protrusion of the wire spring does not become so large, and the switching device body , there is an advantage that the switching valve chamber etc. can be configured compactly (small diameter). In addition, since a wire spring is provided for the switching element, there is no need to provide a separate detent spring to hold the switching element in the switching position as in the past, further reducing costs due to a reduction in the number of parts. can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the reciprocating motion switching device for a pump according to the present invention, and FIG. 2 is a cross-sectional view of the main part thereof. 11... Switching device main body, 13... Actuation rod,
18, 19... working fluid chamber, 22... switching valve chamber,
23...Switching body, 27...Switching element, 64...
Wire spring, 71...Central linear part, 7
2... Straight portions at both ends.

Claims (1)

[Scope of Claims] 1. An operation that is reciprocated by a switching valve chamber provided inside the switching device main body and a working fluid inserted into this switching valve chamber and alternately supplied and discharged to two working fluid chambers. a switching actuator that is loosely fitted in the actuating rod in the axial direction and moved to one side or the other side of the switching valve chamber, and a working fluid that is switched by the switching actuator and supplied to the switching valve chamber. A reciprocating switching device for a pump, comprising a relatively small and lightweight switching element that switches supply and discharge to two working fluid chambers, and a spring that holds the switching body on one side or the other side of the switching valve chamber, As the spring, a wire spring having a substantially C shape is formed by curving both sides of the wire with a straight part located at the center of the wire as a reference and making the straight parts located at both ends face each other. A straight part at the center of the spring is rotatably fitted to one of the switching element and the switching actuating body, and straight parts at both ends of the wire spring are rotatably fitted to the other of the switching element and the switching actuating body. A reciprocating switching device for a pump, characterized in that it is fitted.