JP3742594B2 - Diaphragm pump device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pair of diaphragms that define a liquid feeding chamber and a working fluid chamber, a main body portion that supports a center rod attached to both ends of each diaphragm so as to be able to reciprocate, and reciprocates the center rod. Therefore, the present invention relates to an improvement of a diaphragm pump device having a switching valve device for switching supply of working fluid to both working fluid chambers.
[0002]
[Prior art]
Conventionally, a diaphragm pump device includes a pair of diaphragms that define a liquid feeding chamber and a working fluid chamber, and a main body portion that reciprocally supports center rods attached to both ends of the central portion of each diaphragm. A switch valve device for switching the supply of working fluid to both working fluid chambers in order to reciprocate the center rod is known (for example, see Japanese Patent Publication No. 6-31650).
[0003]
The switching valve device includes a sleeve, a spool provided in the sleeve and reciprocated in the axial direction, and a spring mechanism provided at one axial end of the spool to prevent the spool from stopping at a neutral position. (Dedent mechanism). In this conventional diaphragm pump device, the working fluid is alternately supplied to the working fluid chamber on one diaphragm side and the working fluid chamber on the other diaphragm side, and the supply of working fluid to both working fluid chambers is switched. The center rod is reciprocated, and the volume expansion of one working fluid chamber and the volume expansion of the other working fluid chamber are alternately repeated. By this repetition, fluid is alternately sucked into the two liquid feeding chambers from the suction port. Thus, the fluid sucked into each liquid feeding chamber is alternately discharged from both liquid feeding chambers, and thereby the fluid is continuously discharged from the discharge port.
[0004]
[Problems to be solved by the invention]
By the way, in this conventional diaphragm pump device, the switching valve device has a spring mechanism whose spring mechanism is fixed to the valve device main body as shown in FIG. 1, and as shown in FIGS. The bush member 5 is inserted from the shaft end of the axial one end portion 3 of the spool 2 and is slidably supported by the axial one end portion 3 and is prevented from coming off by the nut 4, and the bush member 5 has both end portions 6a. The contact portion 6b is pivotally attached and is composed of a pair of metal C-shaped linear spring members 6 that are in contact with and supported by the engagement grooves 1a of the spring receiving member 1.
[0005]
In this conventional switching valve device, the curved portion 6c of the linear spring member 6 is deformed by receiving a load as shown by a broken line in FIG. By changing the direction of operation, the spool 2 is prevented from stopping at its neutral position in the axial direction.
[0006]
However, in this conventional switching valve device, the linear spring member 6 is spanned between the spring receiving member 1 and the bush member 5 so as to function as a swing arm, and the spool 2 is reciprocated in the axial direction. Since the deformation stress based on the above is concentrated on the curved portion 6 c of the linear spring member 6, the linear spring member 6 may be damaged due to repeated reciprocation of the spool 3. In addition, since a load is intensively applied to the contact portion 6b of the linear spring member 6, the spring receiving member 1 may be partially worn, and the switching valve device may malfunction.
[0007]
Furthermore, this type of diaphragm valve device is also used today in the field of semiconductor manufacturing industry, where contamination of the production line by metal ions directly affects the quality of the semiconductor, Once the production line is contaminated with metal ions, not only the semiconductor products that are actually flowing through the line are discarded, but also the cleaning and recovery of the contaminated line requires several hours to several days, during which time the production line must be stopped. Therefore, the cost is enormous, and contamination by metal ions is extremely disliked, and it is desired to manufacture the diaphragm pump device with synthetic resin parts as much as possible.
[0008]
However, when the linear spring member 6 used as the spring mechanism of the switching valve device is made of synthetic resin, the synthetic resin has a lower strength than metal, so that there is a problem that the useful life is further reduced.
[0009]
The present invention has been made in view of the above circumstances, and can improve the life and operation stability of a spring mechanism, and has a switching valve device suitable when the spring member is made of resin. An object is to provide an apparatus.
[0010]
[Means for Solving the Problems]
The diaphragm pump device according to claim 1 is a main body for reciprocally supporting a pair of diaphragms defining a liquid feeding chamber and a working fluid chamber, and a center rod having a central portion attached to both ends of each diaphragm. And a switching valve device for switching the supply of the working fluid to both working fluid chambers in order to reciprocate the center rod, the switching valve device being provided in the sleeve and in the axial direction. A diaphragm pump device comprising: a spool reciprocally moved to the shaft; and a spring mechanism that is provided at one end of the spool in the axial direction and prevents the spool from stopping at a neutral position.
The spring mechanism includes a pair of swing arms provided with a free end on the one end side in the axial direction of the spool and symmetrically arranged in the axial direction of the spool, and a pair of swing arms provided on the valve device body. An arm receiving member that supports the base end of the swing arm so as to be swingable, and one end of the swing direction is engaged with the base end of one swing arm, and the direction of curvature is the base end of the other swing arm. The other end is engaged and supported by the arm receiving member via both base ends of the pair of swing arms, and the pair of swing arms swings based on the axial reciprocation of the spool. Accordingly, both ends of the bending direction are composed of a semicircular spring member that is expanded and contracted in the direction of separating and approaching.
[0011]
3. The diaphragm pump device according to claim 2, wherein a bush member is provided at one end of the spool in the axial direction and is slidable in the axial direction of the spool and engages with the free ends of the pair of swing arms. It is characterized by being.
[0012]
The diaphragm pump device according to claim 3 is characterized in that the semicircular spring member is made of a synthetic resin.
The diaphragm pump device according to claim 4, wherein the semicircular spring member is provided with notches extending in the circumferential direction at both ends in the bending direction, and the engaging pieces that engage with the notches are bent. It has both ends in the direction and is engaged with the notch to form a circular shape integrally with the semicircular spring member, and the base end of the swing arm is engaged with the pair of engaging pieces And a semi-circular spring member that is supported by the arm receiving member via the base end portion of the swing arm and that expands and contracts in a direction in which both engagement pieces are separated and approached.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 4 is a longitudinal sectional view of the diaphragm pump device according to the present invention. In FIG. 4, reference numeral 10 denotes the diaphragm pump device. The diaphragm pump device 10 includes a main body portion 11 and a pair of casing members 12 and 12 disposed on both sides of the main body portion 11. Stainless steel (SUS) is used as the material of the main body 11, and the outer peripheral surface of the stainless steel is covered with a Teflon material. Teflon is used as a material for the pair of casing members 12 and 12.
[0014]
The main body 11 and the pair of casing members 12, 12 are integrated by six tie rods 13 extending in the horizontal direction.
A center rod 14 is supported at the center of the main body 11 so as to be able to reciprocate. Disks 14a and 14b are provided at both ends of the center rod 14, and a pair of disk-shaped diaphragms 15 are attached to the disks 14a and 14b.
[0015]
The pair of diaphragms 15 have a curved diaphragm portion 16. The left diaphragm 15 serves to define the liquid feeding chamber 17a and the working fluid chamber 18a, and the right diaphragm 15 serves to define the liquid feeding chamber 17b and the working fluid chamber 18b. The peripheral portion of the diaphragm 15 is sandwiched between the pair of casing members 12 and the main body portion 11.
[0016]
As shown in FIG. 5, a switching valve device 19 is fixed to the main body 11 using a mounting screw 20. The switching valve device 19 has a valve device main body 21. The valve device main body 21 is provided with a sleeve 22 as shown in an enlarged view in FIG. A spool 23 is provided in the sleeve 22 so as to reciprocate in the axial direction (vertical direction).
[0017]
The spool 23 has reduced diameter portions 23a and 23b, expanded diameter portions 23c, 23d and 23e, and one axial end portion 23f. A portion of the reduced diameter portion 23a between the lower enlarged portion 23c and the enlarged diameter portion 23d with the enlarged diameter portion 23d as a boundary serves as a lower chamber 23g, and the upper enlarged diameter portion 23e with the enlarged diameter portion 23d as a boundary. A portion of the reduced diameter portion 23b between the enlarged diameter portion 23d is an upper chamber 23h.
[0018]
In the valve device main body 21, a pressure chamber 21a is provided below the enlarged diameter portion 23c, and a pressure chamber 21b is provided above the enlarged diameter portion 23e. The pressure chamber 21a is provided with a spool drive rod mechanism 24 for driving the spool 23 in the event that the switching valve device 19 is in a malfunction state. Reference numeral 25 denotes a drive rod, and reference numeral 26 denotes an annular seal screw member. The drive rod 25 functions to manually move the spool 23 in the axial direction.
[0019]
The pressure chamber 21b is provided with a spring mechanism (dedent mechanism) 27 for preventing the spool 23 from stopping its operation at its neutral position in the axial direction. The spring mechanism 27 has an arm receiving member 28. The arm receiving member 28 is fixed to the valve device main body 21 by an annular seal screw member 29. The detailed structure of the arm receiving member 28 will be described later.
[0020]
The valve device main body 21 is provided with supply passages 30a to 30d for supplying compressed air as a working fluid. The sleeve 22 is provided with ports 22a to 22e. The supply passage 30a communicates with the pressure chamber 21a through the orifice 31. The supply passage 30d communicates with the pressure chamber 21b through the orifice 32. The supply passage 30b communicates with the port 22a, and the supply passage 30c communicates with the port 22b.
[0021]
The casing 12 member is provided with communication ports 33a and 33b as shown in FIG. The communication port 33a is communicated with the port 22c via a passage 22c ', and the communication port 33b is communicated with the port 22e via a passage 22e'. The communication ports 33a and 33b serve to supply compressed air to the working fluid chambers 18a and 18b and to release compressed air in the working fluid chambers 18a and 18b to the atmosphere through the port 22d.
[0022]
In FIG. 6, the port 22a is opened and the port 22a is communicated with the port 22c through the lower chamber 23g, and the port 22b is closed and the ports 22e and 22d are connected through the upper chamber 23h. The state of communication is shown.
[0023]
The casing member 12 is provided with switching pressure decompression chambers 34a and 34b as shown in an enlarged view in FIG. Compressed air from the pressure chamber 21b is supplied to the switching pressure decompression chamber 34a through the communication path 35b. Compressed air in the pressure chamber 21a is supplied to the switching pressure decompression chamber 34b via the communication path 35a. Push rods 35a and 35b are provided in the switching pressure decompression chambers 34a and 34b. The push rods 35a and 35b face the disks 14a and 14b of the center rod 14 so as to be able to come into contact therewith. A valve body 36 is provided on the push rods 35a and 35b. The switching pressure decompression chambers 34a and 34b communicate with each other through a valve body 36 so as to be opened and closed. The casing member 12 is provided with urging springs 37a and 37b for urging the ends of the push rods 35a and 35b toward the working fluid chambers 18a and 18b. The valve body 36 is opened when the disks 14a and 14b abut against the push rods 35a and 35b, and the switching pressure reducing chambers 34a and 34b and the working fluid chambers 18a and 18b are communicated with each other. The port 22d of the sleeve 22 communicates with the atmosphere via a passage 22d ′.
[0024]
The main body 11 is provided with a suction port 38 and a discharge port 39 as shown in FIG. The suction port 38 communicates with conduits 42 and 43 in which balls 40 and 41 functioning as check valves are arranged. The conduits 42 and 43 are provided with valve seats 44 and 45, and the balls 40 and 41 serve to open and close the openings 44 a and 45 a of the valve seats 44 and 45. The pipe line 42 communicates with the liquid feeding chamber 17a, and the pipe line 43 communicates with the liquid feeding chamber 17b.
[0025]
The discharge port 39 communicates with conduits 50 and 51 in which balls 46 and 47 functioning as check valves are arranged. Valve seats 48 and 49 are provided in the pipes 50 and 51, and the balls 46 and 47 play a role of opening and closing the openings 48a and 49a of the valve seats 48 and 49, respectively. The pipe 50 communicates with the liquid feeding chamber 17a, and the pipe 51 communicates with the liquid feeding chamber 17b.
[0026]
As shown in FIG. 6, the spring mechanism 27 includes a semicircular spring member 52, a pair of swing arms 54, and a bush member 55. The semicircular spring member 52, the swing arm 54, and the bush member 55 are preferably made of synthetic resin as much as possible when the diaphragm pump device 10 is used in the field of the semiconductor manufacturing industry.
[0027]
As shown in FIG. 8, an installation space 56 in which the semicircular spring member 52 is installed is formed in the arm receiving member 28. As shown in FIG. 13, the oscillating arm 54 is formed of a thick rectangular flat plate, one side of which is a rotation base end 54a, and the rotation base end 54a is shown in FIGS. As shown, bearing shafts 54b and 54b are formed. The other side is a free end 54c.
[0028]
As shown in FIGS. 15, 16, and 19, the bush member 55 has an insertion hole 55a through which the axial end portion 23f of the spool 23 is inserted, and an insertion notch 55b. The bush member 55 is slidable in the axial direction of the spool 23, and is prevented from falling off the spool 23 by a head portion 57 'of the axial end portion 23f. The bush member 55 is formed with a pair of engaging grooves 55 c and 55 c at symmetrical positions with respect to the axis of the spool 23. The free ends 54c of the swing arm 54 are engaged with the engaging grooves 55c and 55c.
[0029]
As shown in FIGS. 9 to 11, the arm receiving member 28 is formed with a through hole 57 through which the axial end portion 23 f of the spool 23 passes, and FIGS. 8, 9, 11, and 12. As shown in the figure, a pair of support grooves 58 and 58 for rotatably supporting the support shafts 54b and 54b of the pair of swing arms 54 are formed. The pair of support grooves 58, 58 are disposed at symmetrical positions in the axial direction of the spool 23. The pair of swing arms 54 is inserted into the installation space 56 while the support shafts 54b are engaged and supported in the support grooves 58 and 58, and the free ends 54c thereof are inserted into the engagement grooves 55c and 55c of the bush member 55. Engaged.
[0030]
The semicircular spring member 52 is formed of a semicircular curved plate as shown in FIGS. As shown in FIG. 18, the semicircular curved plate has a rectangular shape when viewed from the upper surface, and the curved direction both ends 52b, 52b extending from the curved direction intermediate portion 52a toward both sides have inner circumferences thereof. Engagement grooves 52c and 52c are formed on the surface side. The rotation base end portions 54a and 54a of the swing arm 54 are engaged with the engagement grooves 52c and 52c.
[0031]
The semicircular spring member 52 is supported by the arm receiving member 28 indirectly through the rotation base end portions 54a and 54a, that is, in a state of floating with respect to the arm receiving member 28. As the pair of swing arms 54 swings based on the axial reciprocation of the spool 23, the semicircular spring member 52 moves away from the curved end portions 52b and 52b as shown by broken lines in FIG. In this direction, the spring force is accumulated and released, and the direction of action of the spring is changed.
[0032]
That is, as shown in FIG. 6, when the spool 23 is moved forward in the direction of the arrow X, the both ends 52b and 52b in the bending direction are moved in the radial direction from the center of the semicircular spring member 52 by the swing arms 54 and 54. An outward force is applied, and the semicircular spring member 52 is deformed outward with the middle portion 52 a in the bending direction as a center, whereby the spring force is accumulated in the semicircular spring member 52. Since the semicircular spring member 52 is deformed as a whole, local concentration of stress is prevented, and fatigue can be reduced. Moreover, since the force by the rocking | fluctuation arm 54 is added to the bending direction both ends 52b and 52b perpendicularly | vertically from a radial direction, the partial wear is also reduced.
[0033]
Next, the operation of the diaphragm pump device 1 will be schematically described.
Now, in FIG. 6, compressed air is supplied to the left working fluid chamber 18a via the port 22a, port 22c, passage 22c 'and communication port 33a of the switching valve device 19, and the center rod 14 is moving rightward. As the volume of the left working fluid chamber 18a is increased, the compressed air in the right working fluid chamber 18b is released to the atmosphere through the communication port 33b, the passage 22e ', the port 22e, the port 22d, and the passage 22d'. It is assumed that the volume of the right working fluid chamber 18b is being reduced. That is, it is assumed that the volume of the left liquid feeding chamber 17a is in the contracting process and the volume of the right liquid feeding chamber 17b is in the expanding process.
[0034]
At this time, the pressure in the left liquid feeding chamber 17a increases, the ball 40 is brought into contact with the valve seat 44, the ball 46 is separated from the valve seat 48, and the fluid in the left liquid feeding chamber 17a is discharged from the discharge port 39. Is done. On the other hand, the pressure in the right liquid feeding chamber 17b is reduced, the ball 41 is separated from the valve seat 45, the ball 47 is brought into contact with the valve seat 49, and the fluid is sucked into the right liquid feeding chamber 17b from the suction port 38. .
[0035]
When the disk 14a comes into contact with the protruding end of the push rod 35a, the push rod 35a is moved in a direction against the urging force of the spring 37a, and the valve body 36 opens the switching pressure decompression chamber 34a and compresses the pressure chamber 21b. Air flows into the right working fluid chamber 18b through the passage 35b and the switching pressure decompression chamber 34a, and is released to the atmosphere through the communication port 33b.
[0036]
The pressure chambers 21a and 21b are evenly pressurized with compressed air, but the switching pressure decompression chamber 34a, the working fluid chamber 18b, the communication port 33b, the passage 22e ', the port 22e, Since the amount of air released to the atmosphere through 22d is large, the pressure balance between the pressure chamber 21a and the pressure chamber 21b is lost, and the pressure in the pressure chamber 21b is lowered. Therefore, the spool 23 is instantaneously moved upward, the port 22b is opened, and the port 22a is closed. Thereby, the compressed air is supplied to the right working fluid chamber 18b via the port 22b, the port 22e, the passage 22e ', and the communication port 33b, and the volume of the right working fluid chamber 18b is expanded. As a result, the center rod 14 is moved in the left direction.
[0037]
At this time, the neutral position of the spring 23 is offset by the bush member 55 with respect to the axial neutral position of the spool 23, and the bush member 55 slides in the axial direction in conjunction with the spool 23. Therefore, the movement of the spool 23 is prevented from being suppressed by the swing resistance of the swing arm 54.
[0038]
[Modification]
As shown in FIG. 20, the semicircular spring member 52 has notches 60, 60 extending in the circumferential direction at both ends 52b, 52b in the bending direction. A semicircular spring member 61 is engaged with the semicircular spring member 52. The semicircular spring member 61 has engagement pieces 62 and 62 that engage with the notches 60 and 60 at both ends 61a and 61a in the bending direction. Engagement grooves 61b and 61b are formed in the engagement pieces 62 and 62 to engage the rotation base end portion 54a of the swing arm 54. The semicircular spring member 61 is supported on the arm receiving member 28 via the rotation base end portion 54 a of the swing arm 54, and the both engagement pieces 62, 62 are separated and approached based on the reciprocating movement of the spool 23. It is to be scaled in the direction that is. In the semicircular spring member 61, as shown in FIG. 21, a through hole 63 through which the axial end portion 23f of the spool 23 passes is formed. The semi-circular spring member 61 is engaged with the semi-circular spring member 52 to form a circular spring member as a whole.
[0039]
According to this structure, since both curved end portions 52b, 52b, 61a, 61a of both semicircular spring members 52, 61 are expanded and contracted based on the reciprocating motion of the spool 23, the acting force of the spring is reduced. This can be increased compared to the embodiment of the invention.
[0040]
【The invention's effect】
According to the first to fourth aspects of the present invention, the life of the spring mechanism can be extended and the operation stability can be improved, and a switching valve device suitable for the case where the spring is made of resin can be obtained.
[Brief description of the drawings]
FIG. 1 is a partial side view showing a configuration of a spring mechanism of a conventional switching valve device.
2 is an exploded perspective view showing a configuration of a spring mechanism shown in FIG. 1. FIG.
3 is a view of the spring mechanism shown in FIG. 1 as viewed from the direction of arrow Y. FIG.
FIG. 4 is a longitudinal sectional view of a diaphragm pump device according to the present invention.
5 is a cross-sectional view taken along the line AA in FIG.
6 is a partially enlarged sectional view of the switching valve device shown in FIG.
7 is a partially enlarged view of a switching pressure decompression chamber shown in FIG.
FIG. 8 is a front view of an arm receiving member.
9 is a cross-sectional view taken along the line BB shown in FIG.
FIG. 10 is a plan view of the arm receiving member shown in FIG.
11 is a cross-sectional view taken along the line CC shown in FIG.
12 is a side view of the arm receiving member shown in FIG. 8. FIG.
13 is a plan view of the swing arm shown in FIG. 6. FIG.
14 is a side view of the swing arm shown in FIG. 6. FIG.
15 is a longitudinal sectional view of the bush member shown in FIG.
16 is a plan view of the bush member shown in FIG. 6. FIG.
17 is a side view of the semicircular spring member shown in FIG. 6. FIG.
18 is a plan view of the semicircular spring member shown in FIG. 6. FIG.
19 is an exploded perspective view of the spring mechanism shown in FIG.
FIG. 20 is a view showing a modification of the spring mechanism of the present invention, and is a plan view showing an assembling relationship among a sleeve, an arm receiving member, a semicircular spring member, and a spool.
21 is a cross-sectional view taken along the line DD in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Diaphragm pump apparatus 11 Main body part 14 Center rod 15 Diaphragm 19 Switching valve apparatus 21 Valve apparatus main body 21b Pressure chamber 22 Sleeve 23 Spool 27 Spring mechanism 28 Arm receiving member 52 Semicircular spring member 54 Swing arm 55 Bush member

Claims (3)

A pair of diaphragms that define a liquid feeding chamber and a working fluid chamber, a main body that supports a center rod attached to both ends of each diaphragm so that the center of each diaphragm can reciprocate, and for reciprocating the center rod A switching valve device for switching the supply of working fluid to both working fluid chambers, the switching valve device including a sleeve, a spool provided inside the sleeve and reciprocating in the axial direction, and a shaft of the spool A diaphragm pump device comprising a spring mechanism that is provided at one end of the direction and prevents a stop at the neutral position of the spool, wherein the spring mechanism is located at one end of the spool and the pair of swing arms, and the switching is performed. an arm receiving member provided adjacent to the pressure chamber of the valve device body of the valve device, formed by slidably inserted into the axial direction of the spool to one end of the spool The pair of swing arms are symmetrically disposed at one end portion of the spool with the central axis of the spool interposed therebetween, and the swing arm is mounted on the arm receiving member. The base end is pivotably supported and the swing arm free end is engaged with the bush member, and the single semi-circular spring member is attached to the arm receiving member with the pair of rockers. A diaphragm pump device, which is supported via each base end portion of the moving arm and is configured to expand and contract with the swing of the pair of swing arms by the reciprocating motion of the spool in the axial direction. . The diaphragm pump device according to claim 1, wherein the semicircular spring member is made of a synthetic resin. Wherein the semicircular spring members respectively provided notch-outs extending circumferentially in said bending opposite end portions,-out the cutting deletion has a engaging piece that engages in the cutout in the curved opposite ends the base end portion of the engaged with or one prior KiYurado arm presents the semicircular spring member and the circular shape is integral is engaged with the pair of engaging pieces to the proximal end of the swing arm parts to claim 1 or claim 2, characterized in Rukoto provided a semicircular spring member the both engaging pieces are scaled in the direction you away closer together is supported on the arm supporting member via a The diaphragm pump device described.

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