JPWO2016006043A1 - Coil spring fixing structure and double reciprocating pump - Google Patents

Abstract

The retainer member (30) has a first retainer (31) having a fitting portion (33) fitted inside the end of the coil spring (14), and a first retainer member (30) fitted inside the first retainer (31). 2 retainers (32). When the first retainer (31) and the second retainer (32) are fitted together, the outer peripheral portion (34) of the tip of the second retainer (32) comes into contact with the inside of the fitting portion (33), so that a plurality of claws (37) spreads outward by wedge action. The retainer member (30) is fixed to the end portion of the coil spring (14) by the plurality of claw portions (37) spreading outward pressing the inside of the end portion of the coil spring (4).

Description

  The present invention relates to a retainer member coil spring fixing structure and a double reciprocating pump, in which a coil spring is mounted on an end of a rod-shaped shaft.

  Conventionally, a pair of closed spaces are divided into a pump chamber and a working chamber by a movable partition member such as a bellows connected by a connecting shaft, and the connecting shaft is reciprocated by alternately introducing a working fluid into the pair of working chambers. 2. Description of the Related Art A double reciprocating pump in which a pump chamber is alternately compressed and expanded by being moved is known.

  In this type of double reciprocating pump, at the end of the reciprocating stroke of the connecting shaft, the pair of suction valves and discharge valves are switched from one pump chamber side to the other pump chamber side, resulting in a discharge flow rate. Pulsations that cause various adverse effects corresponding to the number of strokes occur. For example, a double reciprocating pump disclosed in Patent Document 1 below is known as a pump that suppresses this pulsation and always enables stable pump operation.

  According to this double reciprocating pump, the compression process of one pump chamber and the compression process of the other pump chamber are partially based on the output of the displacement sensor that continuously detects the displacement of the pair of movable partition members. The valve mechanism is switched to drive the pair of movable partition members so as to have overlapping distances.

  By the way, the connection shaft in the conventional double reciprocating pump disclosed in Patent Document 1 is configured to include a coil spring as an expansion / contraction member attached to the shaft. Although the connection between the coil spring and the shaft is not described in detail in Patent Document 1, normally, a retainer member press-fitted and fixed to the end of the coil spring is attached to the end of the shaft. It has been broken.

International Publication No. 2010/143469

  However, in the method in which the retainer member is fixed to the end of the coil spring by press-fitting as described above, for example, when the size of the coil spring increases, the inner diameter tolerance increases, and as a result, the variation in the inner diameter of the manufactured coil spring varies. Since it becomes large, it was difficult to provide an appropriate press-fitting allowance for the retainer member. For this reason, there is a problem that a retainer member cannot be securely fixed to the end portion of the coil spring, particularly when the coil spring is large in size.

  The present invention has been made in view of such a point, and even with a large-sized coil spring, a coil spring fixing structure capable of securely fixing a retainer member to an end portion thereof and mounting it on a shaft, and two An object is to provide a continuous reciprocating pump.

  A coil spring fixing structure according to an embodiment of the present invention is a coil spring fixing structure of a retainer member in which a coil spring is attached to an end of a rod-shaped shaft, and the end of the coil spring is attached to the end of the shaft. A retainer member to be mounted is provided, and the retainer member includes a first retainer having a fitting portion that fits inside an end portion of the coil spring, and a second retainer that fits inside the first retainer. The fitting portion of the first retainer has a plurality of claw portions formed so as to spread outward when the tip outer peripheral portion of the second retainer abuts on the inside, and the first retainer includes the first retainer. (2) The retainer member is fixed to the end portion of the coil spring by the plurality of claws extending outward by wedge action by pressing the inner side of the end portion of the coil spring. It is characterized in.

  In another embodiment of the present invention, the first retainer includes the fitting portion formed in a cylindrical shape that fits inside the end portion of the coil spring, and the tip portion from the tip side of the fitting portion. The plurality of claw portions formed so as to extend toward the base end side, a disk shape having a larger diameter than the fitting portion and abutting on the end portion of the coil spring, and a first screw portion on the inside The second retainer has a second screw portion that is screwed into the first screw portion at a base outer peripheral portion, and the tip outer peripheral portion is the plurality of claws. It is formed in the cylindrical shape arrange | positioned coaxially with respect to the said fitting part and an annular part so that it may contact | abut in a wedge shape inside the toe | tip part of a part.

  A double reciprocating pump according to an embodiment of the present invention includes a case member that internally forms a pair of spaces along the axial direction, and the pair of spaces disposed in the pair of spaces so as to extend and contract in the axial direction. A pair of movable partition members that divide each of the spaces in the axial direction into a pump chamber and a working chamber, a connection shaft that connects the pair of movable partition members in an axial direction via a coil spring, and suction in the pump chamber A suction valve provided on the side for guiding the transfer fluid to the pump chamber, a discharge valve provided on the discharge side of the pump chamber for discharging the transfer fluid from the pump chamber, and a working fluid introduced into the working chamber. And a valve mechanism for discharging the working fluid from the working chamber, and a double reciprocating pump for transferring the transfer fluid by expanding and contracting the pair of movable partition members, the connecting shaft A pair of rod-shaped shafts, the coil spring mounted between the pair of shafts, and a retainer member mounted on the pair of shafts, each attached to an axial end of the coil spring, The retainer member includes a first retainer having a fitting portion that fits inside the end portion of the coil spring, and a second retainer that fits inside the first retainer. The second retainer includes a plurality of claw portions formed so that the outer peripheral portion of the tip of the second retainer is in contact with the inside of the second retainer, and spreads outward by wedge action by fitting the second retainer to the first retainer. Further, the retainer member is fixed to the end of the coil spring by the plurality of claws pressing the inside of the end of the coil spring.

  In one embodiment of the present invention, another coil spring having a smaller diameter than the coil spring is disposed inside the coil spring and between the retainer members.

  According to the present invention, a retainer member can be securely fixed to an end portion of a large coil spring and attached to a shaft.

It is a disassembled perspective view which shows the retainer member applied to the coil spring fixing structure which concerns on one Embodiment of this invention. It is a side view which shows a part in cross section in order to demonstrate the coil spring fixing method by the retainer member. It is a side view which shows a part in cross section in order to demonstrate the coil spring fixing method by the retainer member. It is a disassembled perspective view which shows the modification of the retainer member. It is a perspective view which shows the retainer member applied to another coil spring fixing structure. It is a side view which shows the retainer member. It is a perspective view which shows the retainer member applied to another coil spring fixing structure. It is a side view which shows the retainer member. It is a figure which shows the structure of the double reciprocating pump which applied the coil spring fixing structure which concerns on one Embodiment of this invention. It is a fragmentary sectional view of the connection shaft in the pump. It is a fragmentary sectional view of the other connection shaft in the pump.

  Hereinafter, a coil spring fixing structure and a double reciprocating pump according to embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is an exploded perspective view showing a retainer member applied to a coil spring fixing structure according to an embodiment of the present invention. 2 and 3 are side views showing a part in cross section for explaining a method of fixing a coil spring by a retainer member. The retainer member 30 applied to the coil spring fixing structure according to the present embodiment is made of a resin molded member such as polyphenylene sulfide (PPS).

  The retainer members 30 are respectively attached to the end portions of the coil springs 14. As shown in FIG. 1, the retainer member 30 includes a first retainer 31 attached to the end of the coil spring 14 and a second retainer 32 that fits inside the first retainer 31. The first retainer 31 includes a cylindrical fitting portion 33 that fits inside the end portion of the coil spring 14, and a disk-shaped annular portion that has a larger diameter than the fitting portion 33 and contacts the end portion of the coil spring 14. Part 35. The fitting part 33 and the annular part 35 are integrally formed.

  The fitting portion 33 of the first retainer 31 has a claw portion formed such that a claw root portion 37b is located toward the tip end side of the fitting portion 33 and a toe portion 37a is located toward the annular portion 35 side. 37 are provided at equal intervals along the circumferential direction of the fitting portion 33. The claw portions 37 have a tip end outer peripheral portion 34, which will be described later, abuts against a tapered surface 37d provided on the inside of the claw portion 37, whereby the toe portion 37a side spreads outward with respect to the claw root portion 37b. It is formed as follows.

  For example, a U-shaped slit 37 c is formed around each claw portion 37. The slit 37c communicates with a round hole 37e formed near the nail root portion 37b. The round hole 37e is provided in order to disperse the concentration of stress applied to the nail root portion 37b when the nail portion 37 is displaced and to improve the mechanical strength of the nail portion 37. A first screw portion 35 a is formed inside the annular portion 35.

  The 2nd retainer 32 is formed in the cylindrical shape by which the 2nd screw part 32a screwed together with the 1st screw part 35a of the 1st retainer 31 was formed in the outer side. A tapered outer peripheral portion 34 is formed on the distal end side of the second retainer 32. The tip outer peripheral portion 34 abuts against the tapered surface 37d inside the toe portion 37a of each claw portion 37 in a wedge shape. The second retainer 32 is coaxially disposed with respect to the fitting portion 33 and the annular portion 35 of the first retainer 31.

  The retainer member 30 configured as described above is attached to the coil spring 14 as shown in FIGS. That is, as shown in FIG. 2, first, the first retainer 31 is attached to the coil spring 14 so that the fitting portion 33 is fitted inside the end portion of the coil spring 14 and the annular portion 35 is in contact with the end portion. Insert and place at the end.

  Next, the second retainer 32 is inserted inside the first retainer 31, and a jig or the like for rotational tightening is inserted into a pair of radially opposed grooves 32b formed on the rear end surface of the second retainer 32, The second retainer 32 is rotated little by little about the axial direction of the coil spring 14 so that the second screw portion 32a meshes with the first screw portion 35a, and the second retainer 32 is placed inside the first retainer 31. Screw together.

  When the screwing of the second retainer 32 with respect to the first retainer 31 proceeds, the tip outer peripheral portion 34 of the second retainer 32 comes into contact with the tapered surface 37d of each claw portion 37 of the first retainer 31 in a wedge shape. And the front-end | tip outer peripheral part 34 of the 2nd retainer 32 pushes each claw part 37 in the fitting part 33 of the 1st retainer 31 gradually so that the toe part 37a may spread outside.

  Thereby, as shown in FIG. 3, the outer peripheral surface of each claw part 37 formed in the fitting part 33 of the first retainer 31 abuts on the inner side of the end part of the coil spring 14, and the end part of the coil spring 14 is moved. In a state of pressing from the inside, the second retainer 32 is fitted to the first retainer 31, and the retainer member 30 is attached to the end of the coil spring 14. Finally, the coil spring 14 is mounted by mounting the retainer members 30 respectively attached to the ends of the coil spring 14 to a pair of rod-shaped shafts (not shown), for example.

  As described above, if the coil spring 14 is mounted on the shaft using the retainer member 30 having the above-described structure, for example, the inner diameter tolerance that increases as the size of the coil spring 14 becomes larger than the conventional size. The variation of the inner diameter generated in the coil spring 14 manufactured based on the above is sufficiently absorbed, and the retainer member 30 is securely attached to the end of the coil spring 14 while being centered with respect to the coil spring 14 and slidably mounted on the shaft. It becomes possible to do. One of the retainer members 30 may be fixedly attached to the shaft.

  FIG. 4 is an exploded perspective view showing a modified example of the retainer member. In addition to the retainer member 30 described above, the basic configuration is the same. For example, a retainer member having the following structure may be used. That is, as shown in FIG. 4A, the retainer member 30 </ b> A is the same as the retainer member 30 in that the retainer member 30 </ b> A includes the first retainer 31 and the second retainer 32, but is formed in the fitting portion 33 of the first retainer 31. The difference is that the circumferential size of the plurality of claw portions 37 is reduced and the number is increased from four to eight. However, when the number of the claw portions 37 is four, the advantage is that the strength of the mold can be increased.

  Further, as shown in FIG. 4B, the retainer member 30B has a point that the round hole 37e in the vicinity of the claw root portion 37b of each claw portion 37 in the fitting portion 33 of the first retainer 31 of the retainer member 30A is omitted. This is different from the retainer member 30A. Even if the retainer members 30 </ b> A and 30 </ b> B configured as described above are used, the same operational effects as those of the fixing structure when the retainer member 30 is used can be obtained.

  FIG. 5 is a perspective view showing a retainer member applied to another coil spring fixing structure. FIG. 6 is a side view showing the retainer member. FIG. 7 is a perspective view showing a retainer member applied to still another coil spring fixing structure. FIG. 8 is a side view showing the retainer member.

  As shown in FIGS. 5 and 6, the retainer member 50 is made of a resin molded member, similar to the retainer member 30 and the like. The retainer member 50 is integrally formed into a cylindrical fitting portion 51 that fits inside the end portion of the coil spring 14 and a disk shape that contacts the end portion of the coil spring 14 and has a larger diameter than the fitting portion 51. And an annular portion 52.

  Further, the retainer member 50 includes a drop-off prevention stopper 53 that is formed on the outer peripheral surface of the fitting portion 51 and serves as a stopper portion that prevents the fitting portion 51 from dropping off from the end of the coil spring 14. 51 and an anti-rotation protrusion 54 as a displacement prevention part that prevents the displacement of the fitting position between the end of the coil spring 14 and the fitting part 51 formed at a predetermined position of the step part of the annular part 52. .

  The stopper 53 for preventing the retainer member 50 from falling off is formed so as to make one round of the outer peripheral surface of the fitting portion 51 along the winding direction of the coil spring 14. Further, the rotation preventing projection 54 in the retainer member 50 is formed so as to contact the spring end 14 a in the winding direction at the end of the coil spring 14.

  The retainer member 50 configured as described above is attached to the end portion by rotationally inserting the end portion of the coil spring 14 with the axial direction as a rotation axis. Then, the retainer member 50 is detached from the coil spring 14 in the axial direction after the retainer member 50 is attached to the end portion of the coil spring 14 and the retainer member 50 after the retainer member 50 is attached to the end of the coil spring 14 by the above-described drop prevention stopper 53 and rotation prevention protrusion 54. Rotational movement with respect to the coil spring 14 is prevented.

  As shown in FIGS. 7 and 8, the retainer member 60 is made of a resin molded member and has a fitting portion 61 and an annular portion 62 as in the case of the retainer member 50. The retainer member 60 has a wall-shaped drop-off prevention stopper 63 formed along the circumferential direction on the outer peripheral surface on the distal end side of the fitting portion 61, and predetermined positions of the step portions of the fitting portion 61 and the annular portion 62. And an anti-rotation protrusion 64 formed on the surface.

  The stopper 63 for preventing the retainer member 60 from falling off is formed so as to protrude in a direction intersecting with the axial direction of the coil spring 14 and to substantially circulate the outer peripheral surface of the fitting portion 61. Further, the rotation preventing projection 64 of the retainer member 60 abuts on the spring end portion 14a in the same manner as the rotation preventing projection 54.

  And in the predetermined location in the circumferential direction between the stopper 63 for drop-off prevention and the protrusion 64 for rotation prevention in the fitting part 61, a state where the step from the tip of the fitting part 61 to the annular part 62 is cut out. A plurality of slits 65 are formed. In the illustrated example, a total of three slits 65 are formed in the vicinity of both ends of the drop-off prevention stopper 63 and one in the vicinity of the rotation prevention protrusion 64.

  The retainer member 60 configured in this manner is attached to the end portion by pressing and inserting the end portion of the coil spring 14 along the axial direction. The plurality of slits 65 are fitted to the portion where the stopper 63 for drop-off is formed in order to prevent the stopper 63 from coming off against the coil spring 14 from being difficult to insert when the retainer member 60 is inserted. It is provided to make the portion 61 easily bent inward. Also with the retainer member 60 having such a structure, it is possible to prevent axial disengagement and rotational movement from the coil spring 14.

  FIG. 9 is a diagram showing a configuration of a double reciprocating pump to which the coil spring fixing structure according to one embodiment of the present invention is applied. FIG. 10 is a partial cross-sectional view of a connection shaft in a double reciprocating pump, and FIG. 11 is a partial cross-sectional view of another connection shaft in the pump. As shown in FIG. 9, the double reciprocating pump to which the coil spring fixing structure according to this embodiment is applied is a double cylinder type, and is configured as follows, for example.

  As shown in FIG. 9, a pair of bottomed cylindrical cylinders 2a and 2b, which are case members, are coaxially disposed on both sides of the pump head 1 disposed in the center, and the inside of the pair of cylinders 2a and 2b. A pair of spaces is formed. In the pair of spaces, a pair of bellows 3a and 3b each having a bottomed cylindrical shape are coaxially arranged.

  The open ends of the bellows 3a, 3b are fixed to the pump head 1, and the shaft fixing plates 4a, 4b are fixed to the bottom thereof. The bellows 3a and 3b are made of, for example, fluororesin, and constitute movable partition members that partition the internal spaces of the cylinders 2a and 2b with the insides being pump chambers 5a and 5b and the outside being working chambers 6a and 6b.

  The bellows 3a and 3b are provided with, for example, a crest 28a and a trough 28b that are alternately formed along the axial direction. A ring portion 29 is provided. The number of the ring portions 29 can be arbitrarily configured. The bellows 3a, 3b are configured by the number of peak portions 28a and valley portions 28b that have the same shape, the same thickness, and the same operating resistance as those of a normal bellows without the ring portion 29. The bellows 3a, 3b having such a structure is superior in temperature characteristics to the bellows without the ring portion 29, and can improve the pressure resistance performance without reducing the operation efficiency.

  One ends of shafts 7a and 7b extending coaxially are fixed to the shaft fixing plates 4a and 4b. The other ends of the shafts 7a and 7b extend through the center of the bottoms of the cylinders 2a and 2b through the seal member 8 to the outside of the cylinders 2a and 2b. Connecting plates 9a and 9b are fixed to the other ends of the shafts 7a and 7b by nuts 10, respectively. The connecting plates 9a and 9b are connected by connecting shafts 11a and 11b at the upper and lower positions of the cylinders 2a and 2b in the drawing.

  Here, the connection shafts 11a and 11b will be described in detail. As shown in FIG. 10, each of the connecting shafts 11 a and 11 b has rod-shaped shafts 12 and 13, a coil spring 14 mounted between the shafts 12 and 13, and an axial end of the coil spring 14. The retainer member 30 is mounted and attached to the metal sleeve 40 of each of the shafts 12 and 13. In FIG. 10, only the connecting shaft 11 is shown, but the same configuration can be adopted for the connecting shaft 11b.

  The connecting shafts 11 a and 11 b are fitted and fixed in, for example, a recess 13 a at the end of the shaft 13, and an opening 12 b at the end of the shaft 12 in the space 12 a formed inside the shaft 12. There is provided a rod-like slide shaft 39 disposed so as to be capable of moving forward and backward in the axial direction via a bearing portion 38 attached inside. The bearing portion 38 is composed of, for example, a linear ball bearing.

  At the ends of the shafts 12 and 13 of the connecting shafts 11a and 11b, a metal sleeve 40 having a convex cross section made of a metal material such as stainless steel attached and fixed by a bolt 41 is disposed. At least one bolt 41 in the shaft 12 fixes the bearing portion 38 together with the metal sleeve 40.

  The retainer member 30 is attached to the ends of the shafts 12 and 13 via the metal sleeve 40. The coil spring 14 is centered by the retainer member 30 and is slidably mounted on the shafts 12 and 13 via the metal sleeve 40. Each connecting shaft 11a, 11b is fixed to the connecting plates 9a, 9b by bolts 15.

  The pump head 1 of the double reciprocating pump is provided with a suction port 16 and a discharge port 17 for the transfer fluid at a position facing the side surface of the pump. Further, the pump head 1 is provided with suction valves 18a and 18b at positions from the suction port 16 to the pump chambers 5a and 5b, and discharge valves 19a and 19b are provided at a path from the pump chambers 5a and 5b to the discharge port 17. It has been.

  Proximity switches 21a and 21b are mounted on the bottom outer wall surfaces of the cylinders 2a and 2b. The proximity switches 21a and 21b are for detecting that the bottoms of the bellows 3a and 3b are most retracted. For example, the proximity switches 21a and 21b detect that the inner side surfaces of the connecting plates 9a and 9b are close to each other. Displacement sensors 23a and 23b are mounted on the fixing plates 22a and 22b extending from the cylinders 2a and 2b.

  The displacement sensors 23a and 23b detect displacement with respect to the outer surfaces of the connecting plates 9a and 9b. For example, a laser displacement meter, an MR (magnetoresistive element) sensor, a capacitance sensor, a linear encoder, a high-frequency oscillation type proximity displacement A sensor, an optical fiber type displacement sensor, or the like can be suitably used. Detection signals from the proximity switches 21a and 21b and the displacement sensors 23a and 23b are input to a controller 25 that controls the double reciprocating pump.

  On the other hand, air (working fluid) from an air source (working fluid source) such as an air compressor (not shown) is supplied to the electromagnetic valves 27a and 27b after being restricted to a predetermined pressure by the regulators 26a and 26b, respectively. For this reason, since the pressure fluctuation of one working chamber 6a, 6b does not affect the pressure of the other working chamber 6b, 6a, it has the pulsation reduction effect by this.

  The regulators 26a and 26b are not limited to two, and may be configured by one. In this case, a precision regulator can be used. Here, it is assumed that the solenoid valve 27a is in an off state (exhaust state), the solenoid valve 27b is in an on state (air introduction state), the pump chamber 5a is in an expansion process, and the pump chamber 5b is in a contraction process. .

  At this time, since the suction valve 18a and the discharge valve 19b are in the open state and the suction valve 18b and the discharge valve 19a are in the closed state, the liquid to be transferred as the transfer fluid is introduced into the pump chamber 5a from the suction port 16, It is discharged from the pump chamber 5b through the discharge port 17. At this time, the output of the displacement sensor 23b is lowered with the separation of the connecting plate 9a.

  The controller 25 monitors the output of the displacement sensor 23b, and when the magnitude of the output of the displacement sensor 23b falls below a predetermined threshold value THR, for example, the electromagnetic valve 27a is turned on to introduce air into the working chamber 6a. . Thereby, the pump chamber 5a is switched from the expansion process to the compression process.

  However, at this time, since air is continuously supplied to the other working chamber 6b, the pump chamber 5b also maintains the compression process. Accordingly, the suction valves 18a and 18b are closed, the discharge valves 19a and 19b are opened, and liquid is discharged from both the pump chambers 5a and 5b. The coil springs 14 of the connecting shafts 11a and 11b are compressed to absorb the dimensional change between the both ends of the bellows 3a and 3b.

  When the proximity switch 21b detects the stroke end, the solenoid valve 27b is switched to air exhaust. And since the bellows 3b is pulled by connection shaft 11a, 11b and starts expansion | extension, the pump chamber 5b switches to an expansion process. By repeating the above operation in the left and right pump chambers 5a and 5b, the liquid is transferred. In the double reciprocating pump configured as described above, since the above-described coil spring fixing structure is applied, the movement of the connecting shafts 11a and 11b can be smoothly followed even in a wide range of pulsation pressures.

  The connecting shafts 11a and 11b may have the following configuration, for example. As shown in FIG. 11, each of the connecting shafts 11 a and 11 b has a double spring configuration in which an auxiliary coil spring 70 and an auxiliary retainer 71 are provided between the shafts 12 and 13 and between the retainer members 30 inside the coil spring 14. Yes.

  The auxiliary coil spring 70 has a smaller diameter than the coil spring 14 and is disposed between the coil spring 14 and the slide shaft 39. The auxiliary retainer 71 includes an insertion portion 72 that is inserted into the end portion of the auxiliary coil spring 70 and a disk portion 73 that contacts the end portion of the auxiliary coil spring 70. Each of the auxiliary retainers 71 is attached to the end of the auxiliary coil spring 70 by, for example, press-fitting. The back surface side of the disk portion 73 of the auxiliary retainer 71 is supported in a state where at least one of the auxiliary retainer 71 can contact and be separated from the distal end surface of the metal sleeve 40. If such double spring type coupling shafts 11a and 11b are employed, the movement of the coupling shafts 11a and 11b can be smoothly followed even in a wider range of pulsation pressures.

DESCRIPTION OF SYMBOLS 1 Pump head 2a, 2b Cylinder 3a, 3b Bellows 4a, 4b Fixed plate 5a, 5b Pump chamber 6a, 6b Actuating chamber 7a, 7b Shaft 9a, 9b Connecting plate 11a, 11b Connecting shaft 12, 13 Shaft 14 Coil spring 14a Spring end Part 30, 50, 60 Retainer member 31 First retainer 32 Second retainer 32a Second screw part 33 Fitting part 34 Tip outer peripheral part 35 Annular part 35a First screw part 37 Claw part 37a Toe part 37b Claw root part 37c Slit 37d Taper Surface 37e Round hole 38 Bearing part 39 Slide shaft 40 Metal sleeve 70 Auxiliary coil spring 71 Auxiliary retainer 72 Insertion part 73 Disk part

Claims (4)

A retainer member coil spring fixing structure in which a coil spring is attached to an end of a rod-shaped shaft,
A retainer member for attaching the end of the coil spring to the end of the shaft;
The retainer member includes a first retainer having a fitting portion that fits inside an end portion of the coil spring, and a second retainer that fits inside the first retainer,
The fitting portion of the first retainer has a plurality of claw portions formed so as to spread outward when the tip outer peripheral portion of the second retainer abuts inside.
When the second retainer is fitted to the first retainer, the plurality of claw portions that are spread outward by the wedge action press the inside of the end portion of the coil spring, so that the retainer member is attached to the coil spring. Coil spring fixing structure characterized by being fixed to the end. The first retainer is formed in a cylindrical shape that fits inside the end portion of the coil spring, and the distal end portion extends from the distal end side to the proximal end side of the fitting portion. The plurality of claws, and an annular portion having a diameter larger than that of the fitting portion and formed in a disk shape that contacts the end of the coil spring and has a first screw portion formed inside. ,
In the second retainer, a second screw portion that is screwed into the first screw portion is formed on the outer peripheral portion of the base end, and the outer peripheral portion of the distal end abuts in a wedge shape on the inner side of the toe portions of the plurality of claw portions. The coil spring fixing structure according to claim 1, wherein the coil spring fixing structure is formed in a cylindrical shape arranged coaxially with respect to the fitting portion and the annular portion. A case member that forms a pair of spaces along the axial direction inside;
A pair of movable partition members arranged in the pair of spaces so as to be expandable and contractable in the axial direction, respectively, and partitioning the pair of spaces into the pump chamber and the working chamber in the axial direction;
A coupling shaft that couples the pair of movable partition members in an axial direction via a coil spring;
A suction valve that is provided on the suction side of the pump chamber and guides a transfer fluid to the pump chamber;
A discharge valve provided on the discharge side of the pump chamber for discharging the transfer fluid from the pump chamber;
A valve mechanism for introducing a working fluid into the working chamber and discharging the working fluid from the working chamber;
A double reciprocating pump for transferring the transfer fluid by expanding and contracting the pair of movable partition members;
The connecting shaft includes a pair of rod-shaped shafts, the coil spring mounted between the pair of shafts, and a retainer member mounted on the pair of shafts, each attached to an axial end of the coil spring. With
The retainer member includes a first retainer having a fitting portion that fits inside an end portion of the coil spring, and a second retainer that fits inside the first retainer,
The fitting portion includes a plurality of claw portions formed so as to spread outward when the tip outer peripheral portion of the second retainer abuts inside.
When the second retainer is fitted to the first retainer, the plurality of claw portions that are spread outward by the wedge action press the inside of the end portion of the coil spring, so that the retainer member is attached to the coil spring. A double reciprocating pump characterized by being fixed to the end. The double reciprocating pump according to claim 3, wherein another coil spring having a smaller diameter than the coil spring is disposed inside the coil spring and between the retainer members.

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