JPH0781551B2 - Reciprocating motion switching device for pump - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Industrial field of application) The present invention relates to a reciprocating motion switching device used in a pump that reciprocates by automatic switching of fluid pressure.

(Prior Art) For example, as a reciprocating motion switching device of a diaphragm pump,
There is one disclosed in JP-B-42-23303.

As shown in FIG. 5, this is provided with a switching mechanism portion 12 provided inside the switching device body 11, and is inserted into the switching mechanism portion 12 and alternately supplied to and discharged from the two working fluid chambers 13 and 14. An operating rod 15 that is reciprocated by the operating fluid, and a switching actuating body 19 that is loosely fitted between the large diameter portion 16 and the sleeve 17 of the operating rod 15 and is moved to one side or the other side of the switching valve chamber 18. ,
A concave switch 21 for switching the supply and discharge of the working fluid supplied to the switching valve chamber 18 to the two working fluid chambers 13 and 14, and a neutral position with respect to the switching operating body 19. There is a spring 22 that holds the switching actuating body 19 on one side or the other side of the switching valve chamber 18 by applying an elastic pressing force in the orthogonal direction.

Then, the reciprocating motion of the operating rod 15 causes the switching actuator 19
Is moved, and the switching element 21 is slid by the switching actuator 19, and the two operating fluid chambers (air chambers) are moved by the switching element 21.
Switching control of supply and discharge of working fluid (air) to 13,14,
The operating rod 15 is continuously reciprocated.

Diaphragms 23 and 24 are integrally provided at both ends of the operating rod 15. The diaphragms 23, 24 partition and form the working fluid chambers 13, 14 and the pump chambers 25, 26, and the volumes of the pump chambers 25, 26 change as the working rod 15 moves. A pumping action is obtained. For example, when the actuating rod 15 moves to the right, the liquid inside the pump chamber 25 on one side is pushed out through the check valve 27 on the discharge side due to the volume contraction of the pump chamber 25 and is discharged from the discharge port 28 to the outside. Is discharged. Further, due to the volume expansion of the pump chamber 26 on the other side, liquid is sucked into the pump chamber 26 from the suction port 29 through the suction side check valve 30. Such a pump action causes the switching mechanism section.
By the automatic switching of the working fluid in 12, the right and left are alternately repeated.

In this conventional reciprocating motion switching device, a structure in which a pressing force is applied from the spring to the switching actuating body 19 is such that a cylindrical slider 31 is fitted to one end of a compression coil spring 22 and an end face recess 32 of the slider 31 is actuated. One end spherical portion 34 of the child 33 is rotatably fitted, and the other end spherical portion 35 of the operator 33 is rotatably fitted in the recess 36 of the switching actuating body 19.

As described above, since the compression coil spring 22 is conventionally used, it is necessary to interpose the tubular slider 31 and the operating element 22 between the spring 22 and the switching operation body 19. The work of assembling these parts is not easy and is a cause of cost increase.

On the other hand, Japanese Laid-Open Patent Publication No. 60-256571 discloses a reciprocating motion switching device in which a pair of spool valve springs are provided on a spool valve body for switching the reciprocating motion of a piston.
This spool valve spring is a wire spring formed in a meandering shape (Fig. 6 of the publication), and the outer ends of the meandering spring are fixed to the inside of the pump housing by screws (the top right column of the publication, page 7). (Lines 8 to 11) and the inner loops of the serpentine spring are engaged in the grooves of the spool valve body (publication page 7, upper right column, lines 13 to 16).

(Problems to be Solved by the Invention) Since the meandering spring described in JP-A-60-256571 has its ends fixed by screws and free rotation of the ends is restricted, Since the spring wire is twisted and a sufficient reversing stroke cannot be obtained by twisting, there is no choice but to form a meandering shape and secure a sufficient distance between the end and loop for the reversing operation. In addition to requiring a large spring mounting space, metal fatigue of the spring wire due to torsion cannot be ignored.

Further, the meandering spring acts on the loop at the time of compression because the inner loops are engaged with the grooves of the spool valve body and the ends of the loops are open so as to be freely movable in the axial direction. Forces may escape in the axial direction. Further, the meandering spring needs to be fixed at its end to the pump housing with a screw, and even after the fixing, if the screw is loosened, the meandering spring may fall off and the function may be impaired. Be careful when assembling.

The present invention has been made in view of such a point, and it is possible to reduce the number of parts, ease of assembly and cost reduction, and obtain a large reversing stroke even in a small size.
It is an object of the present invention to provide a reciprocating motion switching device for a pump, which has a spring shape capable of effectively accumulating a compressive force, and a wire mounting structure which has excellent durability with less metal fatigue of the wire.

[Structure of Invention]

(Means for Solving Problems) The present invention provides a switching mechanism that is provided inside the switching device body 41 and that controls the supply and discharge of the working fluid alternately supplied to or discharged from the two working fluid chambers 42 and 43. Part 44 and this switching mechanism part 44
Associated with the reciprocating movement of the working rod 45 that is loosely fitted in the working rod 45 in the axial direction and that is reciprocated by the working fluid that is inserted into the working fluid chambers 42 and 43 and is alternately supplied to and discharged from the two working fluid chambers 42 and 43. And a switching actuation body 61 that is moved to the switching position on the other side and a switching actuation body 61 by applying elastic pressing force in the orthogonal position at the neutral position to the switching actuation body 61. Is a reciprocating motion switching device for a pump having a wire spring 71 for pressing one of the switching positions to the other switching position, and the wire spring 71 has both ends with respect to a linear portion 74 located at the center of the wire. The portions 72 are bent in the directions opposite to each other and formed into a substantially C shape, and both ends 72 of the wire spring 71 are formed in the lateral direction of the switching actuation body 61 or a member 66 integral with the switching actuation body. This wire is rotatably fitted in the hole 73 Linear portion of pulling 71
74 is a spring receiving portion provided in the switching device body 41
It is rotatably fitted to 75. Further, the switching actuating body 61 is switched by the switching actuating body 61 and supplies / discharges the working fluid supplied to the switching mechanism portion 44 to / from the two working fluid chambers 42, 43.
Valves 91, 92, 94 that switch by contact and separation with 6, 88, 89
Is provided.

(Operation) According to the present invention, the switching operation body 61 is moved as the operation rod 45 moves, and as the switching operation body 61 approaches the neutral position, the switching operation body 61 and the spring receiving portion are moved.
When the wire spring 71 between the wire spring 71 and 75 is compressed while rotating around the linear portion 74 as a fulcrum, and when the switching actuation body 61 passes the neutral position even slightly, the restoring force stored in the wire spring 71 is actuated. Release to the moving side of the rod,
The switching operation body 61 loosely fitted in the axial direction of 45 is instantly moved to the locking position in the movement direction of the operation rod within the loose fitting range. By the operation of the switching actuation body 61, the valves 91, 92, 94 are also instantaneously moved, and the supply and discharge of the working fluid to the working fluid chambers 42, 43 are switched in an instant.

Also, when assembling the parts, the linear part 74 of the wire spring 71 is
While fitting both ends into the spring receiving portion 75, both ends 72 of the wire spring 71 are slightly opened to fit into the switching operation body 61 or the lateral hole 73 of the member 66 integral with the switching operation body 61 by its own restoring force.

(Example) Hereinafter, the present invention will be described in detail with reference to the examples shown in FIGS. 1 to 4.

As shown in FIGS. 1 and 2, the switching device main body 41
A switching mechanism section 44 for switching the supply and discharge of the working fluid (for example, air) alternately supplied to or discharged from the two working fluid chambers 42, 43 is provided inside the chamber. An operating rod 45 which is reciprocated by the working fluid alternately supplied to and discharged from the two working fluid chambers 42 and 43 is inserted. A packing 47 is fitted to a portion of the switching device body 41 where the central cylindrical portion 46 is fitted with the operating rod 45.

A large-diameter portion 51 is integrally formed on the operating rod 45, and a pair of diaphragm holding disks are provided via a spacer 52.
53 is fitted and integrated by tightening a nut 55 which is screwed with the screw portion 54. A central portion of a diaphragm 56 is held between the disks 53.

A sleeve-shaped switching actuating member 61, which is moved between a switching position on one side and a switching position on the other side in association with the reciprocating movement of the operating rod 45, is loosely fitted in the operating rod 45 in a certain range in the axial direction. Has been done. The switching actuation body 61 includes an inner diameter large portion 63 slidably fitted to the large diameter portion 51 of the operating rod 45 and an inner diameter small portion 64 engaged with the large diameter portion 51 or the spacer 52. Then, a valve engaging convex portion 65 is integrally provided on the outer peripheral surface of the large inner diameter portion 63, and a spring fitting 66 is fitted on the outer peripheral surface of the small inner diameter portion 64. It is fixed by a nut 67 screwed onto the outer peripheral surface of the.

By applying an elastic pressing force to the switching actuation body 61 in the orthogonal position in the neutral position, the switching actuation body 61 is switched to the one side switching position shown in FIG. 1 or the other side switching shown in FIG. A pair of wire springs 71 that are pressed to the positions are provided symmetrically on the upper side and the lower side of the switching operation body 61. As shown in FIG. 3, the wire springs 71 oppose each other until both ends 72 of a wire (piano wire) having a round cross section are parallel to a linear part 74 located at the center of the wire. It is curved in a certain direction and formed into a substantially C shape. Both ends 72 of the wire spring 71 are rotatably fitted in a hole 73 formed in the lateral direction of the spring fitting body 66, and a linear portion 74 of the wire spring 71 is formed in the switching device body 41. A recessed groove 76 of a spring receiving portion 75, which is integrally provided in, is rotatably fitted.

The switching mechanism section 44 will be described. The switching device body 41
Is provided with a working fluid supply port 81 and a working fluid discharge port 82, and the valve chambers 83 receiving the working fluid from the working fluid supply port 81 are opposed to the holes 84 in the partition wall of the switching device body 41. Is formed between a pair of working fluid supply side valve seats 85 and 86 that are fitted together, and this valve chamber 83 passes through the valve seats 85 and 86, and one working fluid chamber 42 or the other working fluid chamber 43. Be communicated to.

Further, a through hole 87 communicating with the working fluid discharge port 82 is formed through the partition wall of the switching device main body 41, and the working fluid discharge side valve seats 88 and 89 are provided in opposite directions on both sides of the through hole 87. The through hole 87 communicates with the working fluid chamber 42 on one side or the working fluid chamber 43 on the other side through the valve seats 88 and 89.

The working fluid supply side valve seat 85 and the working fluid discharge side valve seat 88 for the working fluid chamber 42 on one side are integrally molded on a common rubber plate, and the valve seats 86, 89 on the other side are formed.
Is also integrally molded on a common rubber plate. And
Each of the rubber plates is held by a holding plate 90 fitted in recesses on both sides of the partition wall of the switching device body 41.

A part of a first working fluid discharge control valve 91 formed in a disc shape is opposed to one side of the working fluid discharge side valve seat 88 so as to be freely contactable and separable, and a central portion of the valve 91 is a switching actuation body.
It is fitted in 61 and is slidable in the axial direction between the engaging convex portion 65 and the spring fitting body 66. The shaft 93 of the second working fluid discharge control valve 92 facing the other working fluid discharge side valve seat 89 is integrally screwed to the first working fluid discharge control valve 91, and the valve chamber
Shaft 95 of working fluid supply control valve 94 loosely fitted in 83
Are integrally screwed together. Wires 96 are inserted into the shafts 93 and 95 of these valves 92 and 94 to prevent positional displacement due to rotation of the shafts.

Thus, the switching actuation body 61, the valve 94,91, which switches by the contact and separation of the valve seat 85,86,88,89 of the two working fluid chambers 42,43 of the working fluid supplied to the switching mechanism portion 44. 92 is provided and is switched by the switching actuator 61.

Next, the operation of the embodiment will be described with reference to FIGS. 1 and 2.

In the switching state shown in FIG. 1, compressed air as the working fluid supplied to the working fluid supply port 81 is pumped from the valve chamber 83 to the left working fluid chamber 43 through the left working fluid supply side valve seat 86. Then, the operating rod 45 is moved to the left along with the bulging operation of the diaphragm to the left, which does not appear in the drawing on the left side. Then, due to the pushing action of the right diaphragm 56 that moves together with the working rod 45, the air in the right working fluid chamber 42 is discharged from the working fluid discharge port 82 through the right working fluid discharge side valve seat 88 and the through hole 87. Exhausted to the outside.

Then, when the movement of the operating rod 45 to the left approaches the limit, the spacer 52 integrated with the operating rod 45 causes the switching actuator to move.
After the engagement, the switching actuation body 61 is also moved to the left as the actuation rod 45 moves, and as the switching actuation body 61 approaches the neutral position, the switching actuation body 61 is engaged. The pair of wire springs 71 between the spring receiving portion 75 and the spring receiving portion 75 are compressed while rotating leftward about the linear portion 74 as a fulcrum, and the upper and lower wire springs 71 are linear. Over the wire spring 71
The restoring force stored in is released in the movement direction of the operating rod,
The switching actuation body 61 loosely fitted in the axial direction of the actuation rod 45 is instantaneously moved leftward within the loose fitting range. Then, as shown in FIG. 2, the spring fitting body 66 integrated with the switching actuation body 61 collides with the disc-shaped valve 91, and the valves 91, 92, 94
Is instantaneously switched, and the supply and discharge of the working fluid to and from the working fluid chambers 42 and 43 are switched in an instant.

In the state shown in FIG. 2, compressed air as a working fluid supplied to the working fluid supply port 81 is pumped from the valve chamber 83 to the right working fluid chamber 42 through the right working fluid supply side valve seat 85. Then, the actuation rod 45 is moved to the right as the right diaphragm 56 expands to the right. Then, due to the pushing action of the left diaphragm (not shown) that moves together with the working rod 45, the air in the left working fluid chamber 43 passes through the left working fluid discharge side valve seat 89 and the through hole 87 and the working fluid discharge port 82. Exhausted from the outside.

Then, when the movement of the actuation rod 45 to the right approaches the limit, the large diameter portion 51 of the actuation rod 45 engages with the small inner diameter portion 64 of the switching actuation body 61, and after this engagement, the actuation As the rod 45 moves, the switching actuation body 61 also moves, and as the switching actuation body 61 approaches the neutral position, the switching actuation body 61 moves.
A pair of wire springs 71 between the spring 61 and the spring receiving portion 75 are compressed while rotating to the right with the linear portion 74 as a fulcrum, and the wire spring 71 is moved to the upper and lower linear portions 74.
When the neutral position between them is passed even slightly, the restoring force stored in the wire spring 71 is released in the movement direction of the operation rod, and the switching operation body 61 loosely fitted in the axial direction of the operation rod 45.
Is instantaneously moved to the right within its loose fitting range. Then, as shown in FIG. 1, the engaging convex portion 65 of the switching actuation body 61.
Collides with the disc-shaped valve 91, the valves 91, 92, 94 are instantaneously switched, and the supply and discharge of the working fluid to the working fluid chambers 42, 43 are switched in an instant.

Such an operation is repeated and the diaphragm pump is continuously reciprocated.

As described above, the substantially C-shaped wire spring 71 freely rotates with the linear portion 74 and both end portions 72 serving as a rotation center axis and smoothly inverts. 72
Only the bending acts on the curved portion between and, and the twist does not act. Therefore, the C-shaped wire spring 71 can obtain a large reversing stroke even when it is small, and has excellent durability with less metal fatigue of the wire.

Further, this C-shaped wire spring 71 has its both ends 72
Is fitted into the lateral hole 73 of the spring fitting body 66, and the spring fitting body 66 and the C-shaped wire spring 71 constitute an endless spring. When compressed between the 66 and the spring receiving portion 75, there is no escape area for the compression force, and the compression force is effectively accumulated in the C-shaped wire spring 71.

Next, when assembling the wire spring 71, the wire spring 71 is fitted in the concave groove 76 of the linear portion 74 spring receiving portion 75, and both ends 72 of the wire spring 71 are opened against the elasticity of the spring. And is fitted into the hole 73 of the spring fitting body 66 integrated with the switching actuation body 61.

The wire spring 71 may be formed into a substantially C shape as a whole. For example, as shown in FIG. 4, the wire spring 71 is provided with winding parts 99 on both sides.
Since "a" is also formed into a substantially C shape as a whole, it is included in the wire spring of the present invention. Further, the wire springs 71, 71a are not limited to the round cross section, and
You may shape | mold by the wire of irregularly shaped cross sections, such as a square.

EFFECTS OF THE INVENTION According to the present invention, a substantially C-shaped wire spring is formed by bending both ends of a linear portion located at the center of a wire rod in a direction opposite to each other. Since the portion is rotatably fitted in the spring receiving portion of the switching device body, and further, both ends of the wire spring are rotatably fitted in the lateral holes of the switching actuating body or a member integrated therewith. , The linear portion of the C-shaped wire spring is fitted into the spring receiving portion, and the both ends of the C-shaped wire spring are slightly opened and fitted into the lateral hole by their own restoring force, which is particularly fixed. There is an advantage that the wire spring can be installed very easily without being removed, and it does not come off after the installation.Because of the small number of parts, it is possible to significantly reduce the cost compared to the conventional product. You can

Further, according to the present invention, the linear portion and both ends of the C-shaped wire spring freely rotate around the rotation center axis, the wire spring smoothly reverses, and the linear portion and both ends are Since only the bending acts between the curved parts between them and no twisting occurs, a large reversing stroke can be obtained even with a small wire spring that does not require a mounting spacer, and the metal fatigue of the wire material is small and it has excellent durability. There is also an effect to have. Further, since both ends of the C-shaped wire spring that face each other are fitted into the lateral holes, an endless spring is formed,
When the C-shaped wire spring is compressed between the switching actuator or the integral member and the spring receiving portion, there is no escape area for the compression force, and the compression force is effectively accumulated in the C-shaped wire spring.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a reciprocating motion switching device for a pump of the present invention, FIG. 2 is a sectional view showing its switching state, and FIG. 3 is a main part showing its wire spring fitted state. FIG. 4 is a plan view showing a modification of the wire spring, and FIG. 5 is a cross-sectional view of a diaphragm pump incorporating a conventional reciprocating motion switching device. 41 …… Switching device body, 42,43 …… Working fluid chamber, 44 …… Switching mechanism part, 45 …… Working rod, 61 …… Switching actuating body, 71…
… Wire springs, 72 …… ends, 73 …… holes, 74 …… straight parts, 75 …… spring receiving parts, 85,86,88,89 …… valve seats, 91,92,94 …… valves.

Claims (2)

[Claims] 1. A switching mechanism portion provided inside a switching device body for controlling the supply and discharge of a working fluid alternately supplied to or discharged from two working fluid chambers, and two actuations inserted through the switching mechanism portion. A working rod reciprocated by a working fluid alternately supplied to and discharged from the fluid chamber, and a switching position on one side and a switching position on the other side in relation to the reciprocating motion of the working rod that is loosely fitted in the working rod in the axial direction. And a switching actuating body that is moved to and a resilient actuating force that is orthogonal to the switching actuating body in the neutral position to press the switching actuating body to one switching position or the other switching position. A reciprocating motion switching device for a pump having a spring, wherein the switching seat is configured to perform switching operation by the switching actuation body and supply / discharge of the working fluid supplied to the switching mechanism section to / from two working fluid chambers. A valve is provided for switching by contact and separation with respect to the wire. As the spring, a substantially C-shaped wire spring is formed by bending both ends of a linear portion located at the center of the wire in a direction in which the wire spring faces each other. Both ends of the spring are rotatably fitted into holes formed in the lateral direction of the switching actuation body or a member integrated with the switching actuation body, and the linear portion of the wire spring is attached to the switching device body. A reciprocating motion switching device for a pump, which is rotatably fitted to a spring receiving portion provided. 2. A switching mechanism section, wherein a switching device main body is provided with a working fluid supply port and a working fluid discharge port,
A pair of working fluid supply side valve seats are provided to face each other between the valve chamber to which the working fluid is supplied from the working fluid supply port and the one side working fluid chamber and the other side working fluid chamber. A pair of working fluid discharge side valve seats are provided in opposite directions between the portion communicating with the fluid discharge port and the one side working fluid chamber and the other side working fluid chamber, and one working fluid discharge side valve seat is provided. A first working fluid discharge control valve that is movable toward and away from the disk is formed in a disc shape and is loosely fitted in the switching actuating body in the axial direction, and the other working fluid discharge control valve is discharged to the first working fluid discharge control valve. A second working fluid discharge control valve facing the side valve seat is integrally provided, and a working fluid integrated with the first working fluid discharge control valve is provided in a valve chamber between the pair of working fluid supply side valve seats. Supply control valve is free Reciprocating switching device for the pump of Claims paragraph 1, wherein the being.