JP6145392B2 - Diaphragm pump - Google Patents

Description

  The present invention relates to a diaphragm pump including a rolling diaphragm.

  Conventionally, for example, a diaphragm pump described in Patent Document 1 is known as a diaphragm pump used for supplying a liquid such as a chemical solution in a manufacturing process of a semiconductor, a liquid crystal, an organic EL, a solar cell, an LED, or the like. .

  This type of diaphragm pump includes a cylinder (housing), a piston accommodated in the cylinder so as to be reciprocally movable in the axial direction thereof, a rolling diaphragm configured to operate in accordance with the reciprocating movement of the piston, A linear actuator (drive device) having an output shaft composed of a screw shaft connected to the piston so as to serve as a motor portion and a piston rod is provided.

  The linear actuator is attached to the cylinder, and is configured to convert the rotary motion of the motor unit into a linear motion to output the piston from the output shaft to reciprocate the piston in the axial direction. Yes. The output shaft is coaxially arranged on the piston and connected by screw coupling, and can reciprocate in the axial direction integrally with the piston.

  However, in the diaphragm, the output shaft of the linear actuator is inserted into the cylinder from the opposing surface facing the cylinder in the main body of the linear actuator by a member until it is screwed to the piston. It was not supported and was not guided for reciprocation in the axial direction. The output shaft was only stretched between the main body of the linear actuator and the piston.

  Therefore, at the time of reciprocating movement of the piston accompanying the output of the output shaft, the piston rattles in the radial direction of the cylinder (a direction perpendicular to or intersecting the axial direction), and the rolling diaphragm is twisted or distorted. This rolling diaphragm may not operate (deform) normally. That is, the quantitative property of the liquid transfer amount of the diaphragm pump may be impaired.

  In addition, in the diaphragm pump, the following non-rotating means that restricts the rotation by allowing the piston to reciprocate between the piston and the cylinder screwed to the output shaft of the linear actuator. Since it was provided, the piston was more loose, and the quantitative property of the liquid transfer amount of the diaphragm pump was easily impaired.

  That is, the anti-rotation means includes a long hole formed along the axial direction on the side wall of the cylinder, and an engagement pin protruding in a radial direction from the outer peripheral surface of the piston so as to pass through the long hole. It consists of The engagement pin is passed through the long hole so that the protruding end portion is located outside the cylinder, and can be reciprocated integrally with the piston while being guided by the long hole. .

  Therefore, in the detent means, the engagement between the engagement pin and the elongated hole is loose. Therefore, during the reciprocating movement of the piston, the piston that receives rotational input from the output shaft rattles in the circumferential direction of the cylinder, and the rolling diaphragm is twisted or distorted, and the rolling diaphragm operates normally (deforms). ) As a result, the quantitativeness of the liquid transfer amount of the diaphragm pump is easily impaired.

JP 2007-23935 A

  This invention is made in view of such a situation, and it aims at providing the diaphragm pump which can suppress effectively the fall of the quantitative property of the liquid transfer amount resulting from operation | movement of a rolling diaphragm. To do.

  According to a first aspect of the present invention, there is provided a housing, a piston disposed coaxially with respect to the housing in the housing and provided so as to be reciprocally movable in an axial direction of the housing, and one axial direction end of the piston. A shaft configured to be interlocked while being in contact with the side, a lid disposed on one side in the axial direction of the piston, an open end attached to the housing, and the lid and the open A rolling diaphragm having a folded portion disposed between the end portion and the open end portion fixed in position by the housing so that the lid portion reciprocates integrally with the piston; A pump that is partitioned by the rolling diaphragm on one side in the axial direction of the rolling diaphragm in the housing and configured to change the volume of the room. A chamber, a motor unit, and an output shaft that is arranged coaxially with the shaft and connected to the other axial end of the shaft, and is attached to the other axial center side of the housing, A driving device capable of converting the rotary motion of the motor unit into a linear motion to output the shaft from the output shaft to the shaft in order to reciprocate the piston in the axial direction via the shaft; and more than the piston in the housing A guide member disposed on the other side in the axial direction and attached to the housing and capable of guiding the shaft so as to be movable in the axial direction; and the housing on the other side in the axial direction than the guide member in the housing A diaphragm pump provided between the shaft and a regulating mechanism capable of regulating the rotation around the axis while allowing the shaft to reciprocate in the axial direction. A.

  According to this configuration, the shaft can be reciprocated while being guided by the guide member. Therefore, during the reciprocating movement of the shaft, the shaft and the piston linked to the shaft are less likely to rattle in the radial direction of the housing (a direction perpendicular to or intersecting with the axial direction), thereby twisting or distorting the rolling diaphragm. It will be easier to operate (deform) normally without misuse. Therefore, it is possible to effectively suppress a decrease in the quantitativeness of the liquid transfer amount caused by the operation of the rolling diaphragm.

  The invention according to claim 2 is the diaphragm pump according to claim 1, wherein the restriction mechanism is fixed to the shaft, a rail-shaped guide member provided in the housing so as to extend in the axial direction thereof, It is comprised from the linear guide which has the slide member with which the said guide member was mounted | worn and which can move relatively with respect to the said guide member.

  According to this configuration, the shaft and the piston can be further less likely to rattle in the radial direction of the housing when the shaft reciprocates. Therefore, it is possible to more effectively suppress a decrease in the quantitativeness of the liquid transfer amount.

  According to a third aspect of the present invention, in the diaphragm pump according to the second aspect, the slide member sandwiches the other axial end of the shaft and the one axial end of the output shaft. The shaft and the output shaft are connected to each other.

  According to this configuration, the shaft and the output shaft of the drive device can be easily assembled and separated. Therefore, the maintenance of the diaphragm pump can be simplified. In addition, the shaft and the output shaft can be moved in the axial direction while maintaining a stable connected state.

  The invention according to claim 4 is the diaphragm pump according to any one of claims 1 to 3, wherein the piston has a fitting recess that fits one axial end of the shaft. The shaft is configured so as to be interlocked with the shaft by fitting one end of the shaft in the axial direction into the fitting recess while being detachably contacted.

  According to this configuration, the piston and the shaft can be easily assembled and separated. Therefore, the maintenance of the diaphragm pump can be simplified. Further, it is possible to prevent the piston from being deformed due to the connection between the piston and the shaft.

  According to a fifth aspect of the present invention, in the diaphragm pump according to any one of the first to fourth aspects, the piston has a recess opening on the lid side of the rolling diaphragm, and the rolling diaphragm is And a protrusion that can be fitted in the recess, and the protrusion is attached to the piston in a state in which the protrusion is fitted in the recess of the piston.

  According to this configuration, it is possible to make the rolling diaphragm difficult to deform with respect to the piston when an impact is applied to the liquid in the pump chamber in the suction process of the diaphragm pump or the like. In addition, the rolling diaphragm and the piston can be aligned with each other by fitting the protrusion and the recess, and the decrease in the quantitativeness of the fluid transfer amount can be further effectively suppressed.

  ADVANTAGE OF THE INVENTION According to this invention, the diaphragm pump which can suppress effectively the fall of the quantitative property of the liquid transfer amount resulting from operation | movement of a rolling diaphragm can be provided.

It is side surface sectional drawing of the diaphragm pump which concerns on one Embodiment of this invention. It is a partial expanded side sectional view of the diaphragm pump concerning one embodiment of the present invention. It is front sectional drawing of the diaphragm pump which concerns on one Embodiment of this invention. It is side surface sectional drawing of the diaphragm pump which concerns on one Embodiment of this invention. It is a figure which shows the connection part of the shaft and output shaft of a drive device in the diaphragm pump which concerns on one Embodiment of this invention, (a) is a side view, (b) is a top view.

  A preferred embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 shows a side sectional view of a diaphragm pump 1 according to an embodiment of the present invention. FIG. 2 is a partially enlarged side sectional view of the diaphragm pump 1. FIG. 3 shows a front sectional view of the diaphragm pump 1.

  As shown in FIGS. 1, 2, and 3, the diaphragm pump 1 includes a housing 2, a piston 3, a shaft 4, a rolling diaphragm 5, a driving device 6, a guide member 7, and a regulating mechanism 8. It has. In the present embodiment, the diaphragm pump 1 is arranged with its longitudinal direction (axial direction) as the vertical direction.

  The housing 2 has a cylinder 11 and a pump head 12 in this embodiment. The cylinder 11 is formed in a cylindrical shape, and is arranged with the axial direction as the vertical direction. The cylinder 11 is made of stainless steel such as SUS304, for example. The cylinder 11 is provided with a vent hole 14 penetrating in a direction intersecting the axial direction. The vent 14 is connected to a decompression device such as a vacuum pump or an aspirator.

  The pump head 12 is formed in a covered cylindrical shape, and is attached to one end side (upper side) in the axial direction of the cylinder 11 so as to close the opening. The pump head 12 has an inner diameter substantially the same as that of the cylinder 11, and constitutes an accommodation space in which the piston 3 can be accommodated together with the cylinder 11. The pump head 12 is made of a fluororesin such as PTFE (polytetrafluoroethylene).

  A suction port 15 penetrating in a direction orthogonal to or intersecting with the axial direction is provided in the peripheral wall portion of the pump head 12. The suction port 15 is connected to a liquid tank (not shown) for storing a liquid such as a chemical solution via a suction-side check valve. The suction-side check valve is configured to allow a liquid flow from the liquid tank to the suction port 15 and prevent a liquid flow in the opposite direction.

  A discharge port 16 penetrating in the axial direction is provided in the lid portion of the pump head 12 so as to be positioned at the central portion (axial center portion) of the lid portion. The discharge port 16 is connected to a liquid supply unit (not shown) via a discharge side check valve. The discharge-side check valve is configured to allow a liquid flow from the discharge port 16 to the liquid supply unit and prevent a liquid flow in the opposite direction.

  The piston 3 is disposed coaxially with respect to the housing 2 in the housing 2 and is provided so as to be capable of reciprocating in the axial direction (vertical direction) of the housing 2. In the present embodiment, the piston 3 is formed in a columnar shape having a diameter smaller than the inner diameter of the housing 2 (the cylinder 11 and the pump head 12), and the cylinder 11 or the pump whose outer peripheral surface is opposed thereto. It arrange | positions so that a predetermined space | interval may be obtained from the inner peripheral surface of the head 12. FIG. The piston 3 is made of, for example, an aluminum alloy.

  As shown in FIG. 2, the piston 3 has a first recess 21 that opens to one end side (upper side) in the axial direction and a second recess 22 that opens to the other end side (lower side) in the axial direction. doing. The first recess 21 and the second recess 22 are provided in the axial center of the piston 3 and are arranged coaxially with each other. Here, the first recess 21 and the second recess 22 are not communicated with each other.

  The piston 3 also has a fitting recess 23 into which one end of the shaft 4 in the axial center direction is fitted. The fitting recess 23 is provided in the axial center of the piston 3 between the first recess 21 and the second recess 22, and is arranged coaxially with the second recess 22. The fitting recess 23 has a smaller diameter than the second recess 22, and is opened to the other axial end side (lower side) of the piston 3 so as to face the second recess 22.

  The piston 3 further has an air passage 25 composed of a linear through hole penetrating in the axial direction (see FIG. 3). A plurality of the air passages 25 are provided, and on the circumference centered on the shaft center outside the first recess 21 and the second recess 22 with respect to the radial direction of the piston 3 (direction orthogonal to the shaft center direction). Are arranged at predetermined intervals.

  The shaft 4 is configured to be interlocked with the piston 3 while being in contact with one end in the axial direction. In the present embodiment, the shaft 4 is configured separately from the piston 3 and includes an axial center one end (upper end) 27 having an outer peripheral surface along the inner peripheral surface of the fitting recess 23. ing. The shaft 4 has a diameter substantially the same as or slightly smaller than the fitting recess 23 of the piston 3, and is formed in a round bar shape. The shaft 4 extends in the axial direction and is disposed coaxially with the housing 2 and the piston 3. The shaft 4 is made of, for example, a hardened steel material such as high carbon chrome bearing steel or a stainless steel such as martensitic stainless steel.

  Thus, in this embodiment, the piston 3 is fitted into the fitting recess 23 while the upper end portion 27 of the shaft 4 is detachably contacted, thereby contacting the shaft 4 at one end in the axial direction. It is configured to work together in the state. The shaft 4 is simply fitted into the fitting recess 23 of the piston 3 from below.

  With such a configuration, the assembly and separation of the piston 3 and the shaft 4 are facilitated, and the maintenance of the diaphragm pump 1 is simplified. Further, deformation of the piston 3 due to the connection between the piston 3 and the shaft 4 is prevented.

  The drive device 6 includes a motor unit 30 and an output shaft 31 that is arranged coaxially with the shaft 4 and connected to the other end side in the axial direction of the shaft 4. The driving device 6 is attached to the other side (lower side) in the axial direction of the housing 2, and the motor unit 30 is configured to reciprocate the piston 3 in the axial direction (vertical direction) via the shaft 4. The rotary motion is converted into a linear motion and can be output from the output shaft 31 to the shaft 4.

  In the present embodiment, the drive device 6 is composed of a linear actuator (motor), and the most advanced position (see FIG. 1) that is the most separated from the most advanced position (see FIG. 1) that is closest to the piston 3 in the housing 2. (See FIG. 4) can be reciprocated in the axial direction. The driving device 6 includes a multiphase stepping motor unit as the motor unit 30 and a linear motion mechanism unit that can convert the rotational motion of the motor unit 30 into a linear motion and output the linear motion.

  The output shaft 31 of the drive device 6 has a round bar-like portion 32 and a screw shaft portion 33 integrally connected to the round bar-like portion 32, together with a screw nut 34 screwed into the screw shaft portion 33, the straight shaft. It is included in the moving mechanism. The output shaft 31 protrudes upward from the facing surface facing the inside of the cylinder 11 in the main body of the driving device 6 toward the inside of the cylinder 11. The output shaft 31 is arranged coaxially with the shaft 4, and on the protruding end portion (upper end portion) side, that is, the other end portion (lower end portion) in the axial direction of the shaft 4 at the round bar portion 32. ) 28.

  Since the linear actuator has substantially the same configuration as a conventional linear actuator, detailed description of other configurations of the linear actuator is omitted.

  The rolling diaphragm 5 is disposed between a lid 35 disposed on one axial direction side of the piston 3, an open end 36 attached to the housing 2, and between the lid 35 and the open end 36. The folded portion 37 is provided. The rolling diaphragm 5 is configured such that the lid 35 reciprocates integrally with the piston 3 with respect to the open end 36 fixed by the housing 2.

  In the present embodiment, the rolling diaphragm 5 is made of a fluororesin such as PTFE (polytetrafluoroethylene) and is disposed coaxially with the piston 3. The rolling diaphragm 5 is formed in a covered cylindrical shape that is folded outward on the other side (lower side) in the axial direction, and the disc-shaped lid part 35 is provided at one end (upper side) in the axial direction. I have. The lid portion 35 has the same diameter as the piston 3 and is disposed at the center of the rolling diaphragm 5.

  The rolling diaphragm 5 includes an opening on the other side (lower side) in the axial direction, and includes the folded portion 37 having a U-shaped cross section around the opening. A cylindrical inner cylinder portion 38 extending in the axial direction is provided between the inner peripheral side end portion of the folded portion 37 and the lid portion 35, and the aforementioned folded end portion 37 and the open end portion 36 provide the A cylindrical outer tube portion 39 extending coaxially with the inner tube portion 38 is provided. The open end portion 36 is provided in a flange shape on the radially outer side of the upper end portion of the outer tube portion 39.

  Here, the inner cylinder part 38, the folded part 37, and the outer cylinder part 39 are formed to be thin (thin film shape) having a thickness of, for example, 1 mm or less and 0.1 mm or more so as to have flexibility. Yes. The lid part 35 and the open end part 36 are formed to be thicker than the inner cylinder part 38, the folded part 37 and the outer cylinder part 39 so as to have rigidity.

  The rolling diaphragm 5 is held in the housing 2, and the open end 36 is strongly sandwiched between the joint surfaces of the cylinder 11 and the pump head 12, whereby the open end 36. Is fixed to the housing 2.

  Further, the rolling diaphragm 5 is provided so as to cover the piston 3 with the lid portion 35 and the inner cylinder portion 38 so that the lid portion 35 abuts and contacts the piston 3. The rolling diaphragm 5 is disposed so as to be positioned between the inner peripheral surface of the housing 2 and the outer peripheral surface of the piston 3 in a state where the folded portion 37 faces a decompression chamber 53 described later.

  The guide member 7 is disposed on the other side (lower side) in the axial direction than the piston 3 in the housing 2 and is attached to the housing 2, and can guide the shaft 4 so as to be movable in the axial direction. It is configured as follows. In the present embodiment, the guide member 7 functions as a partition that partitions the housing 2. The guide member 7 is formed in a plate shape having an outer peripheral surface along the inner peripheral surface of the housing 2, and the outer peripheral surface is connected to the inner peripheral surface of the cylinder 11 without a gap. The guide member 7 is configured to guide the shaft 4 penetrating the shaft center portion, and is configured integrally with the cylinder 11.

  The guide member 7 penetrates the shaft 4 in the axial direction in the axial center portion and directly guides the shaft 4 on the other side (lower side) in the axial direction, while this axial center is on one side (upper side) in the axial direction. The shaft 4 is supported via a bushing 41 provided in the section. This bushing 41 is comprised from resin, such as carbon steel, stainless steel, brass, a fluororesin, or nylon, for example. A packing 42 such as an O-ring is provided between the guide member 7 and the shaft 4. The packing 42 is made of a rubber material such as fluorine rubber, for example. A packing pressing member 43 is provided below the guide member 7 so as to face the packing 42. The packing pressing member 43 is made of stainless steel such as SUS304, for example.

  The guide member 7 is disposed near the piston 3 in the housing 2, and has a guide member main body 45 and a boss portion 46 that protrudes upward from the axial center portion of the guide member main body 45. ing. The boss portion 46 is formed so that the piston 3 can be movably guided by being fitted into the second recess 22 when the piston 3 moves to the most advanced position or a position in the vicinity thereof. In the present embodiment, the bushing 41 extends from the guide member main body 45 to the boss portion 46.

  In the present embodiment, a restricting member 47 is further provided on the opposite side of the boss portion 46 (below the guide member 7) with the guide member main body 45 interposed therebetween. The restricting member 47 is for restricting the upward sliding movement of a slide member 62 described later. The restricting member 47 is made of stainless steel such as SUS304, for example. Here, the regulating member 47 may be disposed so as to be coaxial with the bushing 41 and support the shaft 4. Further, the restriction member 47 can be configured integrally with the packing pressing member 43.

  In the diaphragm pump 1, a pump chamber 51, a drive chamber 52, and a decompression chamber 53 for filling the liquid are formed in the housing 2 by the rolling diaphragm 5, the guide member 7, and the like. It is divided into.

  Specifically, the pump chamber 51 is partitioned by the rolling diaphragm 5 on one side (upper side) in the axial direction of the rolling diaphragm 5 in the housing 2 so that the volume of the chamber can be changed. Yes. In the present embodiment, the pump chamber 51 is formed to be surrounded by the rolling diaphragm 5 and the pump head 12 of the housing 2, and communicates with each of the suction port 15 and the discharge port 16. The pump chamber 51 is configured such that the volume of the chamber changes due to the operation (deformation) of the rolling diaphragm accompanying the reciprocating movement of the piston 3.

  The drive chamber 52 is partitioned by the guide member 7 on the other side (lower side) in the axial direction than the guide member 7 in the housing 2. In the present embodiment, the drive chamber 52 is surrounded by the guide member 7, the cylinder 11 of the housing 2, and the drive device 6. A part of each of the output shaft 31 and the shaft 4 of the driving device 6 is accommodated in the driving chamber 52.

  The decompression chamber 53 is partitioned between the pump chamber 51 and the drive chamber 52 in the housing 2 by the piston 3, the rolling diaphragm 5, and the guide member 7. In the present embodiment, the decompression chamber 53 is formed by being surrounded by the piston 3, the rolling diaphragm 5, the guide member 7, and the cylinder 11 of the housing 2, and communicates with the vent hole 14. Has been.

  The decompression chamber 53 is configured to be decompressed to a predetermined pressure (negative pressure) by the decompression device connected via the vent hole 14 when the diaphragm pump 1 is driven. The decompression chamber 53 is communicated between the upper surface of the piston 3 and the lower surface of the lid portion 35 of the rolling diaphragm 5 through the plurality of air passages 25 provided in the piston 3. Yes.

  The restricting mechanism 8 is provided between the housing 2 and the shaft 4 on the other side in the axial direction than the guide member 7 in the housing 2 and allows the shaft 4 to reciprocate in the axial direction. However, it is configured to be able to regulate the rotation around the axis. In the present embodiment, the restriction mechanism 8 is provided in the drive chamber 52, and is composed of a linear motion guide that can relatively move the moving body along the extending track body.

  Specifically, the regulation mechanism 8 is fixed to the shaft 4 and a rail-shaped guide member (track body) 61 provided in the housing 2 so as to extend in the axial direction so as to face the drive chamber. The slide member (moving body) 62 is mounted on the guide member 61 and can move relative to the guide member 61. The slide member 62 includes a plurality of balls (rolling elements) therein, and is fitted to the guide member 61 through these balls so as to be relatively movable. Thus, the slide member 62 slides with respect to the guide member 61 without rattling.

  The slide member 62 includes a slide part 63 and a connecting part 64 fixed to the slide part 63. The slide portion 63 is attached to the guide member 61 so as to straddle from the axial center side of the housing 2, and is slidable in the axial direction while being guided by the guide member 61. The connecting portion 64 is externally fitted to the shaft 4 and is fixed so as to move integrally with the reciprocating movement of the shaft 4. In addition, when the connecting portion 64 moves upward, it abuts against the restricting member 47, so that the upward movement of the entire slide member 62 is restricted (see FIG. 4).

  In the above configuration, when the driving device 6 is operated to drive the diaphragm pump 1, the output shaft 31 linearly moves in the axial direction along with the rotation of the screw nut 34, thereby causing the shaft 4 to move. The shaft 4 reciprocates, and the suction process in which the shaft 4 moves backward and the discharge process in which the shaft 4 moves upward are repeated alternately. As a result, the liquid stored in the liquid tank can be supplied to the liquid supply unit at a constant and constant flow rate.

  That is, in the suction step, the piston 3 and the lid portion 35 of the rolling diaphragm 5 are moved downward following the backward movement of the shaft 4 (from the state shown in FIG. 4 to the state shown in FIG. 1). To change). In this process, in the rolling diaphragm 5, the length of the inner cylindrical portion 38 and the length of the outer cylindrical portion 39 are increased in the axial direction, and the inner peripheral surface of the housing 2 and the piston The rolling portion 37 is rolled so as to be displaced downward in the gap with the outer peripheral surface 3. As a result, the volume of the pump chamber 51 increases, so that the liquid in the liquid tank is sucked into the pump chamber 51 through the suction port 15.

  Further, in the discharging step, the piston 3 and the lid portion 35 of the rolling diaphragm 5 move upward following the forward movement of the shaft 4 (from the state shown in FIG. 1 to the state shown in FIG. 4). To change). In this process, the rolling diaphragm 5 has a length of the inner cylindrical portion 38 and a length of the outer cylindrical portion 39 which are shortened, and an inner peripheral surface of the housing 2 and an outer peripheral surface of the piston 3. And rolling so that the folded portion 37 is displaced upward. Accordingly, the volume of the pump chamber 51 is reduced, so that the liquid in the pump chamber 51 is discharged from the discharge port 16.

  In the suction process and the discharge process, the decompression chamber 53 is decompressed to a predetermined pressure (negative pressure) by the decompression device connected through the vent hole 14. Therefore, the lower surface of the lid portion 35 of the rolling diaphragm 5 is the upper surface of the piston 3, the inner surface of the inner cylinder portion 38 is the outer peripheral surface of the piston 3, and the outer surface of the outer cylinder portion 39 is the inner periphery of the housing 2. Each surface can be securely adhered to each other.

  In particular, the pressure reducing chamber 53 is provided between the lower surface of the lid portion 35 of the rolling diaphragm 5 and the upper surface of the piston 3 which are in contact with each other as described above by the plurality of air passages 25 provided in the piston 3. Therefore, the lid portion 35 of the rolling diaphragm 5 and the piston 3 can be more reliably brought into close contact with each other.

  Further, in the suction process and the discharge process, the shaft 4 is moved between the main body of the drive device 6 in the housing 2 and the piston 3 by the guide member 7 particularly at a position near the piston 3. It will reciprocate while being guided. In addition, at this time, the restriction mechanism 8 is allowed to reciprocate in the axial direction of the shaft 4 while the rotation around the axial center of the shaft 4 is restricted.

  Therefore, in the diaphragm pump 1, when the shaft 4 is reciprocated, the shaft 4 and the piston 3 interlocked with the shaft 4 are moved in the radial direction of the housing 2 (the cylinder 11 and the pump head 12). The rolling diaphragm 5 can be easily operated (deformed) normally without being twisted or distorted. Therefore, it is possible to effectively suppress a decrease in the quantitativeness of the liquid transfer amount due to the operation of the rolling diaphragm 5.

  In particular, in the present embodiment, the restriction mechanism 8 is composed of a linear motion guide having the guide member 61 and the slide member 62, so that the shaft 4 utilizes the sliding movement of the slide member 62. Then, while being guided by the guide member 61, it smoothly reciprocates in the axial direction. Therefore, when the shaft 4 reciprocates, the shaft 4 and the piston 3 can be further less likely to rattle in the radial direction of the housing 2. Therefore, it is possible to more effectively suppress a decrease in the quantitativeness of the liquid transfer amount.

  FIGS. 5A and 5B are a side view and a plan view of a connecting portion between the shaft 4 and the output shaft 31 of the driving device 6, respectively.

  As shown in FIGS. 5A and 5B, in this embodiment, the slide member 62 of the restriction mechanism 8 sandwiches the axial direction other end (lower end) 28 of the shaft 4 and the output. The shaft 4 and the output shaft 31 are connected to each other by sandwiching the one end (upper end) in the axial direction of the shaft 31, that is, the round bar portion 32.

  Specifically, the connecting portion 64 includes an attachment hole 65 for inserting and attaching the lower end portion 28 of the shaft 4 and the upper end portion (the round bar portion 32) of the output shaft 31, and the attachment hole 65, The pair of fastening portions 67 that form a slit 66 having a predetermined width to connect with the outside and the pair of fastening portions 67 are tightened so as to narrow the distance between the pair of fastening portions 67 (the slit 66). And a fastener 68 such as a bolt that can be attached.

  And the said connection part 64 inserts the lower end part 28 of the said shaft 4 and the round bar-shaped part 32 of the said output shaft 31 in the said attachment hole 65, and is the said pair of pairs by the said fastener 68 in the state externally fitted without the clearance gap. When the fastening portion 67 is fastened, the lower end portion 28 of the shaft 4 and the round bar-like portion 32 of the output shaft 31 are sandwiched and connected to each other.

  With this configuration, the shaft 4 and the output shaft 31 of the drive device 6 can be easily assembled and separated. Therefore, the maintenance of the diaphragm pump 1 can be simplified. The shaft 4 and the output shaft 31 can be moved in the axial direction while maintaining a stable connection state.

  The output shaft of the drive device according to the present invention is the output shaft 31 connected to the shaft 4 using the slide member 62 (the connecting portion 64) of the restriction mechanism 8 in the present embodiment. For example, the output shaft may be connected to a shaft whose rotation is restricted by the action of the restriction mechanism so as to be relatively rotatable.

  Further, in the present embodiment, the piston 3 has the first concave portion 21 opened to the lid portion 35 side of the rolling diaphragm 5 as described above. As shown in FIG. 2, the rolling diaphragm 5 has a protrusion 71 that can be fitted into the first recess 21, and the protrusion 71 is fitted into the first recess 21 of the piston 3. It is attached to the piston 3 in a state.

  The protruding portion 71 of the rolling diaphragm 5 is provided so as to protrude downward from the axial center portion of the lid portion 35, and is disposed coaxially with the first recess 21. The protrusion 71 has an outer peripheral surface along the inner peripheral surface of the first recess 21, and is fitted into the first recess 21 with almost no gap. The first recess 21 is formed shallower than the second recess 22 (so that the axial width is smaller).

  With such a configuration, it is possible to make the rolling diaphragm 5 difficult to deform with respect to the piston 3 when an impact is applied to the liquid in the pump chamber 51 in the suction process of the diaphragm pump 1 or the like. . In addition, the rolling diaphragm 5 and the piston 3 can be aligned with each other by fitting the protrusion 71 and the first recess 21 to further effectively suppress a decrease in the quantitative amount of the fluid transfer amount. be able to.

DESCRIPTION OF SYMBOLS 1 Diaphragm pump 2 Housing 3 Piston 4 Shaft 5 Rolling diaphragm 6 Drive device 7 Guide member 8 Control mechanism 21 Recessed part (1st recessed part)
23 Fitting recess 27 One axial end of shaft 28 Other axial end of shaft 30 Motor portion 31 Output shaft 32 One axial end of the output shaft (round bar)
35 Lid 36 Open end 37 Folding part 51 Pump chamber 52 Drive chamber 53 Decompression chamber 61 Guide member 62 Slide member 71 Projection

Claims (5)

A housing;
A piston disposed coaxially with respect to the housing within the housing and provided so as to be reciprocally movable in the axial direction of the housing;
A shaft configured to be interlocked with the piston in contact with one end in the axial direction; and
A lid portion disposed on one side in the axial direction of the piston, an open end portion attached to the housing, and a folded portion disposed between the lid portion and the open end portion; A rolling diaphragm configured to reciprocate integrally with the piston with respect to the open end portion fixed in position by:
A pump chamber that is partitioned by the rolling diaphragm on one side in the axial direction from the rolling diaphragm in the housing, and configured to be able to change the volume of the chamber;
A motor unit, and an output shaft disposed coaxially with the shaft and coupled to the other axial end of the shaft; and attached to the other axial end of the housing, via the shaft A driving device capable of converting a rotary motion of the motor unit into a linear motion to output the piston from the output shaft to the shaft in order to reciprocate the piston in the axial direction;
A guide member disposed on the other side in the axial direction than the piston in the housing and attached to the housing and capable of guiding the shaft so as to be movable in the axial direction;
It is provided between the housing and the shaft on the other side in the axial direction than the guide member in the housing, and can control the rotation around the axial center while allowing the shaft to reciprocate in the axial direction. A diaphragm pump comprising a regulation mechanism.   The regulation mechanism includes a rail-shaped guide member provided in the housing so as to extend in the axial direction thereof, and a slide member fixed to the shaft and mounted on the guide member and relatively movable with respect to the guide member. The diaphragm pump according to claim 1, comprising a linear motion guide having   The slide member is configured to couple the shaft and the output shaft by sandwiching the other axial end portion of the shaft and sandwiching one axial end portion of the output shaft. The diaphragm pump according to claim 2.   The piston has a fitting recess that fits one end of the shaft in the axial direction, and the shaft is fitted into the fitting recess while bringing the one end in the axial direction of the shaft into contact with each other. The diaphragm pump according to any one of claims 1 to 3, wherein the diaphragm pump is configured to be interlocked with the diaphragm pump. The piston has a recess opening on the lid side of the rolling diaphragm,
The said rolling diaphragm has a protrusion which can be fitted in the said recessed part, and is attached to the said piston in the state which made this protrusion fit in the recessed part of the said piston. Item 5. The diaphragm pump according to any one of items 4 to 4.

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