Pump device

Abstract

This pump device is provided with: a pump head; a diaphragm; a pump body; an adapter member that is disposed between the pump head and the pump body and includes a pressing section that sandwiches the diaphragm with the pump head and a wall section that is continuous with an inner peripheral wall surface of the pressing section and comprises a first wall surface that, in combination with an inner peripheral wall surface of the diaphragm, forms a space section on the rear side of the diaphragm; a pair of first conductive members that are attached to the first wall surface side of the adapter member, have lower end sections that are located in a lower end section of the space section, and face one another across a prescribed gap; a cable section that is electrically connected to each of the pair of first conductive members at a position above the lower end section of the space section; and a detection unit that detects the resistance value between the pair of first conductive members through the cable section and detects liquid leakage into the space section.

Description

Pump equipment

[0001] The present invention relates to a pump device.

[0002] Conventionally, pump devices have been known that have a pump head attached to a pump body that houses the pump's drive mechanism. For example, in pump devices that use a reciprocating member such as a diaphragm, the diaphragm may be damaged during operation. To detect diaphragm damage, for example, a pressure sensor is placed in the space behind the diaphragm to read the pressure value and detect diaphragm damage. Alternatively, for example, the diaphragm may be formed with a multilayer structure consisting of a conductive layer and insulating layers covering both sides thereof, and diaphragm damage may be detected by detecting changes in the resistance value of the conductive layer (see, for example, Patent Documents 1 and 2 listed below).

[0003] JP 2002-168176 A JP 2007-515584 A

[0004] However, using a pressure sensor to detect diaphragm damage requires the installation of an expensive pressure sensor. Furthermore, the diaphragm damage detection methods for the conventional pump devices disclosed in Patent Documents 1 and 2 require the diaphragm to be formed with a multi-layer structure including a conductive layer and an insulating layer. This increases the cost of the diaphragm itself. Thus, adding a diaphragm damage detection function to a pump device currently presents a problem in that it is difficult to reduce the overall cost of the pump device.

[0005] The present invention has been made in consideration of the above circumstances, and aims to provide a pump device that can utilize a diaphragm with an inexpensive configuration and can detect diaphragm damage with an inexpensive configuration.

[0006] The pump device according to the present invention includes a pump head having an inlet and an outlet for a transport fluid. The pump device includes a diaphragm attached to the pump head and forming a pump chamber communicating with the inlet and the outlet. The pump device includes a pump body including a reciprocating member connected to the diaphragm and arranged in the reciprocating direction of the diaphragm, and a drive mechanism capable of driving the reciprocating member in the reciprocating direction of the diaphragm. The pump device also includes an adapter member disposed between the pump head and the pump body, the adapter member including a pressing portion that sandwiches the diaphragm between the pump head and the pump body, and a wall portion having a first wall surface that is continuous with an inner circumferential wall surface of the pressing portion and forms a space together with the inner circumferential wall surface of the pressing portion on the back side of the diaphragm. The pump device also includes a pair of first conductive members attached to the first wall surface of the adapter member, with their lower ends located at the lower end of the space and facing each other with a predetermined gap between them. The pump device also includes a cable portion electrically connected to each of the pair of first conductive members at a position above the lower end of the space. The pump device includes a detection unit that detects a change in resistance between the pair of first conductive members through the cable unit and detects leakage of the transported fluid into the space.

[0007] In one embodiment of the present invention, the adapter member further includes a pair of second conductive members respectively connected to the pair of first conductive members at the upper position, at least a portion of which is disposed on a second wall surface of the wall portion of the adapter member opposite the first wall surface and electrically connected to the cable portion, and the cable portion is electrically connected to the pair of first conductive members via the pair of second conductive members.

[0008] In another embodiment of the present invention, the adapter member further includes a gasket member attached to the second wall surface of the adapter member. The adapter member has a central hole provided in the center of the wall portion through which the reciprocating member is liquid-tightly inserted via the gasket member, and a pair of connection holes provided in the wall portion surrounding the central hole. The gasket member has a first hole through which the reciprocating member is liquid-tightly inserted, and a pair of second holes provided at positions overlapping the pair of connection holes of the adapter member. The first conductive members extend downward from the pair of connection holes on the first wall surface side of the adapter member and extend toward each other along the inner wall surface toward a lower end of the space. The second conductive member is attached to the adapter member with the gasket member sandwiched between it and the second wall surface of the wall portion of the adapter member, and is connected to the cable portion on the second wall surface side of the adapter member.

[0009] In yet another embodiment of the present invention, the pair of first conductive members are made of conductive resin or corrosion-resistant metal formed in a plate shape that is line-symmetrical with respect to a vertical axis passing through the central axis of the central hole.

[0010] In yet another embodiment of the present invention, the first conductive member and the second conductive member are connected to each other via a connecting member that electrically connects them to each other.

[0011] In yet another embodiment of the present invention, the second conductive member is made of conductive resin. The second conductive member has a main body having a plate-like portion that presses the gasket member against the second wall surface and a cylindrical portion having a connection hole into which the electrical connection portion of the cable is inserted. The second conductive member has a pair of claws that protrude from the plate-like portion of the main body, pass through the second hole and the connection hole, and hook onto the first wall surface. The second conductive member has a cylindrical portion that is provided between the pair of claws and has a connection member mounting hole into which the connecting member is mounted together with the first conductive member. The first conductive member has an insertion hole through which the connecting member is inserted toward the connection member mounting hole.

[0012] In yet another embodiment of the present invention, the second conductive member is made of a metal material. The second conductive member has a plate-shaped main body portion that presses the gasket member against the second wall surface and has an insertion hole through which the connecting member is inserted. The second conductive member has a leaf-spring-shaped electrical contact portion that bends from the main body portion toward the pump main body and contacts the electrical connection portion of the cable portion. The first conductive member has a connection member mounting hole portion to which the connecting member inserted into the insertion hole is attached.

[0013] According to the present invention, it is possible to use a diaphragm having an inexpensive configuration, and it is also possible to detect damage to the diaphragm with an inexpensive configuration.

[0014] 12 is a side cross-sectional view schematically showing a pump device according to a first embodiment of the present invention. FIG. 13 is a front view showing a state in which an adapter member is attached to the pump body of the pump device. FIG. 14 is a cross-sectional view taken along line A-A' in FIG. 2. FIG. 15 is an explanatory view showing the adapter member of the pump device. FIG. 16 is an explanatory view showing a gasket member attached to the adapter member. FIG. 17 is an explanatory view showing a connector portion. FIG. 18 is a block diagram showing a circuit configuration for detecting damage to a diaphragm of the pump device. FIG. 19 is a front view showing the adapter member attached to the pump body of a pump device according to a second embodiment of the present invention. FIG. 20 is a front view showing a drive mechanism housed in the pump body of the pump device. FIG. 19 is an enlarged cross-sectional view taken along line B-B' in FIG. 8. FIG. 21 is an explanatory view showing a second conductive member of the pump device. FIG. 22 is a front view showing an adapter member attached to the pump body of a pump device according to a third embodiment of the present invention. FIG. 23 is a front view showing a drive mechanism housed in the pump body of the pump device. FIG. 24 is an enlarged cross-sectional view taken along line C-C' in FIG. 2. FIG. 25 is an explanatory view showing the second conductive member of the pump device.

[0015] Hereinafter, pump devices according to embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the following embodiments do not limit the invention according to each claim, and not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention.

[0016] In the following embodiments, the same or corresponding components are denoted by the same reference numerals, and redundant explanations are omitted. In the embodiments, the arrangement, scale, dimensions, etc. of each component may be exaggerated or minimized, and may not correspond to the actual ones, and some components may be omitted.

[0017] [First embodiment] [Configuration of pump device] Fig. 1 is a side cross-sectional view schematically showing a pump device according to a first embodiment of the present invention. Fig. 2 is a front view showing a state in which an adapter member is attached to a pump body of the pump device. Fig. 3 is a cross-sectional view taken along line A-A' in Fig. 2.

[0018] 1, the pump device 100 of the first embodiment includes a drive mechanism 10 serving as a drive source (drive unit), a pump body 20 that houses the drive mechanism 10, and a pump head 30 that is attached to the front side of the pump body 20. The basic configuration of the pump device 100 of this embodiment, including its internal structure, can be configured as that of a so-called general pump device. Therefore, the following description will be limited to a summary, avoiding detailed description of known configurations.

[0019] The pump device 100 also includes an adapter member 40 disposed between the pump head 30 and the pump body 20 to attach the pump head 30 to the pump body 20. The pump device 100 is attached by being sandwiched between the pump head 30 by the adapter member 40, and includes a diaphragm 50 connected via the adapter member 40 to a shaft member 11, which is a reciprocating member of the drive mechanism 10. Hereinafter, the direction of the pump body 20 toward the pump head 30 will be referred to as the forward direction, and the direction opposite thereto will be referred to as the rearward direction. As shown by the arrows in Figure 1, the forward and rearward movement directions of the diaphragm 50 and the shaft member 11 will be referred to as the reciprocating direction RD.

[0020] The drive mechanism 10 includes, for example, a motor 12, an eccentric cam mechanism 13, and a shaft member 11. The motor 12 rotates a rotary shaft 13a of the eccentric cam mechanism 13 via a gear mechanism 12a. The eccentric cam mechanism 13 converts the rotational motion of the rotary shaft 13a into reciprocating motion of the shaft member 11 by an eccentric cam portion 13b. The shaft member 11 is driven in forward and backward reciprocating directions RD by the reciprocating motion converted by the eccentric cam mechanism 13.

[0021] The shaft member 11 is made of, for example, a rod-shaped metal or resin member. The diaphragm 50 is connected to the front side of the shaft member 11, and the eccentric cam portion 13b of the eccentric cam mechanism 13 is connected to the rear side.

[0022] The shaft member 11 is pushed forward by the eccentric cam portion 13b. At the same time, the front flange portion 11c of the shaft member 11 is pressed forward by the repulsive force of the spring member 14. As a result, the shaft member 11 moves toward the front side of the pump body 20, displacing the diaphragm 50 in an advance direction. Furthermore, the front flange portion 11c of the shaft member 11 is pulled back toward the rear side by the eccentric cam portion 13b with a force stronger than the repulsive force of the spring member 14, causing the shaft member 11 to move toward the rear side of the pump body 20. As a result, the shaft member 11 displaces the diaphragm 50 in a retreat direction.

[0023] The shaft member 11 is pushed and pulled by the eccentric cam portion 13b in the drive mechanism 10, and thereby repeats the forward and backward movements described above, thereby reciprocating in the reciprocating direction RD. A bracket portion 15 facing the front opening 20a of the pump body 20 is provided on the front side (front face) of the drive mechanism 10 to attach an adapter member 40 (described later).

[0024] Furthermore, the drive mechanism 10 is not limited to a configuration including the motor 12 and eccentric cam mechanism 13, as long as it is configured to drive the shaft member 11 at least in a direction in which the diaphragm 50 advances or retreats. The drive mechanism 10 may be configured to employ, for example, an actuator that linearly moves the shaft member 11 by, for example, electromagnetic force.

[0025] The housing portion of the pump body 20 is made of, for example, a resin material. The pump body 20 has a front opening 20a provided on the front side and a pump base 20b. The pump body 20 also has an accommodation space 21 connected to the front opening 20a provided above the pump base 20b. The accommodation space 21 of the pump body 20 is formed, for example, in a cylindrical shape with parallel surfaces at the top and bottom. The accommodation space 21 of the pump body 20 is configured so that a portion thereof (for example, the lower side) is connected to the interior of the pump base 20b. The accommodation space 21 mainly accommodates the drive mechanism 10, as well as, for example, a cable portion 19 serving as wiring and the bracket portion 15 described above.

[0026] The pump body 20 also has a rear wall 22 provided on the rear side. A control board 29, to which the cable 19 is connected, is attached to a back surface (rear surface) 22a of the rear wall 22. Note that the route of the cable 19 is not shown in Figure 1. The control board 29 controls the drive mechanism 10, thereby controlling the operation of the entire pump device 100.

[0027] The control board 29 includes a detection unit 29a (see FIG. 7), which will be described later, for determining whether the diaphragm 50 has been damaged by, for example, detecting leakage of the transported fluid. An operation unit 28 is provided on the rear side of the pump body 20 to enable an operator to perform settings and other operations on the pump device 100.

[0028] [Configuration of Pump Head] The pump head 30 is made of, for example, a resin material or a metal material such as stainless steel. The pump head 30 has a pump chamber 31 formed in its center. The pump chamber 31 is formed together with a diaphragm 50 attached to the pump head 30, and its volume changes with the displacement of the diaphragm 50. In the pump device 100 of this embodiment, for example, a reinforcing plate 30a that reinforces the mechanical strength of the pump head 30 and a cover member 30b that protects the reinforcing plate 30a are attached to the front side of the pump head 30.

[0029] The pump head 30 is attached to the front opening 20a of the pump body 20 via, for example, an adapter member 40 attached to the bracket 15 of the drive mechanism 10. The pump head 30 has a suction port 32 and a discharge port 33 for the transport fluid that communicate with the pump chamber 31. The suction port 32 communicates, for example, with a lower part of the pump chamber 31. The discharge port 33 communicates, for example, with an upper part of the pump chamber 31.

[0030] The pump head 30 is formed with a first connection port 34 on the suction side of the transferred fluid, located below the suction port 32. The pump head 30 also is formed with a second connection port 35 on the discharge side of the transferred fluid, located above the discharge port 33. The first connection port 34 and the second connection port 35 are connected to the pump chamber 31 via the suction port 32 and the discharge port 33, respectively.

[0031] A cylindrical suction-side adapter 37, with an suction valve 36a installed, is connected to the first connection port 34 by a connecting nut 37a. A cylindrical discharge-side adapter 38, with an discharge valve 36b installed, is connected to the second connection port 35 by a connecting nut 37b. The suction-side adapter 37 connects the suction port 32 of the pump head 30 to the suction-side flow path 39a via the suction valve 36a. The discharge-side adapter 38 connects the discharge port 33 of the pump head 30 to the discharge-side flow path 39b via the discharge valve 36b.

[0032] [Configuration of Adapter Member] FIGS. 4A and 4B are explanatory views showing the adapter member of the pump device, with FIG. 4A showing a front view of the adapter member and FIG. 4B showing a cross section of the adapter member.

[0033] The adapter member 40 is made of, for example, a resin material. The adapter member 40 is disposed between the pump head 30 and the front opening 20a of the pump body 20 (see FIG. 1). As shown in FIGS. 2 and 4(a), the adapter member 40 has a plurality of mounting holes 41 arranged at a predetermined pitch. The adapter member 40 also has a plurality of insertion holes 42 arranged at a different predetermined pitch from the mounting holes 41.

[0034] The adapter member 40 is fastened to the bracket portion 15 by fastening means, such as bolts (not shown), inserted into the mounting holes 41. In this way, the adapter member 40 is attached to the pump body 20 so as to close the front opening 20a of the pump body 20. The pump head 30 is then attached to the front side of the pump body 20 via the adapter member 40, for example, by fastening bolts 42a that pass through the reinforcing plate 30a and the insertion holes 42 of the adapter member 40 to nuts (not shown) on the back side of the adapter member 40.

[0035] As shown in FIG. 4( b), the adapter member 40 includes an annular protrusion 43 as a pressing portion that clamps the fixing portion 51 (see FIG. 1 ) located on the outer periphery of the diaphragm 50 against the pump head 30, and a wall portion 44 having a first wall surface 44a. The adapter member 40 defines a recessed space 45 between the inner circumferential wall surface 43a of the annular protrusion 43 and the first wall surface 44a of the wall portion 44, which is continuous with the inner circumferential wall surface 43a. It is also possible to form a flat portion of the adapter member 40 corresponding to the annular protrusion 43 by adjusting the depth of the pump head 30 where the diaphragm 50 is attached. In this case, the flat portion can serve as a pressing portion, and the diaphragm 50 can be pressed against the pump head 30 by this pressing portion to attach them in a liquid-tight manner. Therefore, the pressing portion is not limited to the annular protrusion 43.

[0036] A circular central hole 46 is formed in the center of the wall 44 of the adapter member 40. Furthermore, as shown in FIG. 4A , for example, a pair of connection holes 47 are formed in the wall 44 around the central hole 46 of the adapter member 40. Each connection hole 47 has a hole shape that combines a circular hole and a rectangular hole with the circular hole at the center. The rectangular hole portions of each connection hole 47 are arranged at an angle so that they approach each other from the bottom end to the top end.

[0037] A pair of guide frames 47a that guide the tip end portion of an electrode portion 48 (described later) are formed on the first wall surface 44a below the central hole 46. A drain hole 47b is formed in the adapter member 40, penetrating a portion of the annular protrusion 43 so as to connect the outside to the space 45. A drain bolt 47c (see FIG. 2) is attached to this drain hole 47b.

[0038] [Configuration of Gasket Member] FIGS. 5A and 5B are explanatory views showing the gasket member attached to the adapter member, where FIG. 5A shows a front view of the gasket member and FIG. 5B shows a cross section of the gasket member.

[0039] The gasket member 60 is made of, for example, rubber. The gasket member 60 is attached to the second wall surface 44b (see FIG. 4(b) ) of the wall portion 44 of the adapter member 40, opposite the space portion 45. As shown in FIG. 5(a) , for example, the gasket member 60 has a disk portion 61 and a central protrusion 62 provided at the center of the disk portion 61 and having an uneven shape in the reciprocating direction RD (a bellows-like shape in a direction intersecting the reciprocating direction RD). The disk portion 61 is attached in contact with the second wall surface 44b of the wall portion 44 of the adapter member 40. The central protrusion 62 is inserted liquid-tightly into the central hole 46 of the wall portion 44 of the adapter member 40 and is exposed to the space portion 45.

[0040] The gasket member 60 also has a first hole 63 and a pair of second holes 64. The first hole 63 is formed in the center of the central protrusion 62, and the shaft member 11 (see FIG. 2) is inserted therethrough in a liquid-tight manner. The pair of second holes 64 are formed at positions on the disk portion 61 corresponding to the pair of connection holes 47 of the adapter member 40 and the reciprocating direction RD when the gasket member 60 is attached to the adapter member 40. Each second hole 64 is formed to have the same shape as the connection hole 47 of the adapter member 40 described above. The arrangement of each second hole 64 is the same as the arrangement of each connection hole 47 of the adapter member 40 described above.

[0041] As shown in Figures 4(a) and 5(a), the pair of connection hole portions 47 of the adapter member 40 and the pair of second hole portions 64 of the gasket member 60 are arranged, for example, to be positioned at the same horizontal height as the central hole portion 46 or at a position higher than this position.

[0042] 1, the diaphragm 50 is connected to the shaft member 11 inserted through the first hole 63 of the central protrusion 62 of the gasket member 60. The diaphragm 50 is a member in which an insert bolt 52 is integrally molded inside a resin such as ethylene propylene rubber (EPDM) or polytetrafluoroethylene (PTFE).

[0043] The diaphragm 50 is driven in the reciprocating direction RD by the drive mechanism 10 housed in the pump body 20 so as to change the volume of the pump chamber 31 of the pump head 30. The diaphragm 50 has a fixed portion 51 sandwiched between the pump head 30 and the annular protrusion 43 of the adapter member 40. The diaphragm 50 is attached in a liquid-tight manner with the front side of its central portion 53 facing the pump chamber 31. A retainer 54, for example, is disposed between the diaphragm 50 and the tip of the shaft member 11 to maintain the shape and position of the diaphragm 50.

[0044] Then, after the gasket member 60 shown in Figure 5 is attached to the adapter member 40 shown in Figure 4, a pair of first conductive members, that is, electrode portions 48, and a pair of second conductive members, that is, connector portions 70, are attached to the wall portion 44 of the adapter member 40, as shown in Figures 2 and 3.

[0045] [Configuration of Electrode Portions] The pair of electrode portions 48 are attached, for example, to the first wall surface 44a of the wall portion 44 of the adapter member 40. The pair of electrode portions 48 extend downward from positions in the space portion 45 corresponding to the pair of connection holes 47 (not shown). At the same time, the pair of electrode portions 48 extend downward into the space portion 45 while curving along the inner circumferential wall surface 43a of the annular protrusion 43, approaching each other. The pair of electrode portions 48 are positioned such that their tips face each other with a predetermined gap between them. The respective tips of the pair of electrode portions 48 are held by the respective guide frames 47a.

[0046] The pair of electrodes 48 are made of, for example, a conductive resin or a corrosion-resistant metal, formed in a plate shape that is line-symmetrical with respect to a vertical axis passing through the central axis of the central hole 46. Examples of the conductive resin include modified polyphenylene ether (m-PPE) containing carbon filler (CF), polypropylene (PP), polyamide (PA), and other resins. Examples of the corrosion-resistant metal include stainless steels such as SUS304, SUS316, and SUS316L; nickel; titanium; alloys such as Alloy 20, Alloy B2, and Alloy C276; gold; platinum; silver; copper; brass; and aluminum.

[0047] [Configuration of Connector Portion] Meanwhile, the pair of connector portions 70 are made of, for example, the conductive resin. The pair of connector portions 70 are attached to the second wall surface 44b of the wall portion 44 of the adapter member 40. Specifically, the pair of connector portions 70 are attached to the second wall surface 44b with the disk portion 61 of the gasket member 60 sandwiched therebetween, and are then connected to the pair of electrode portions 48, respectively. As shown in FIG. 3 , the electrode portions 48 and the connector portions 70 are connected to each other via, for example, connecting screws 69, which are connecting members that electrically connect them.

[0048] Figure 6 is an explanatory diagram showing the connector portion 70, with Figure 6(a) showing the front of the connector portion 70, Figure 6(b) showing the top surface of the connector portion 70, and Figure 6(c) showing a cross section of the connector portion 70. Figure 7 is a block diagram showing a circuit configuration for detecting damage to the diaphragm of the pump device.

[0049] 6(a) to 6(c), each connector portion 70 has a main body portion 71, a pair of claw portions 72, and a cylindrical portion 73. The main body portion 71 has a plate-shaped portion 71a and a cylindrical portion 71b. As shown in FIG. 3, the plate-shaped portion 71a is pressed against the disk portion 61 of the gasket member 60. A connection hole 71c is formed in the cylindrical portion 71b, into which a connection pin 19a, which is an electrical connection portion of the cable portion 19, is inserted.

[0050] The pair of claws 72 protrude from the plate-like portion 71 a of the main body 71 on the side opposite to the side where the cylindrical portion 71 b is formed. The pair of claws 72 pass through the second hole 64 of the gasket member 60 and the connection hole 47 of the adapter member 40, and have engaging portions that engage with the first wall surface 44 a of the wall portion 44.

[0051] The cylindrical portion 73 is provided between the pair of claw portions 72. The cylindrical portion 73 is formed with a connection member attachment hole 73a to which the connection screw 69 is attached together with the electrode portion 48. Note that, at the connection point of the pair of electrode portions 48 and the connector portion 70, an insertion hole 48a is provided through which the connection screw 69 is inserted toward the connection member attachment hole 73a.

[0052] Each connector portion 70 is attached so that the direction of the connection hole 71c formed in the cylindrical portion 71b of the main body portion 71 is inclined upward toward the central hole 46, in accordance with the shapes of the connection hole 47 of the adapter member 40 and the second hole 64 of the gasket member 60. This structure makes it easy to insert the connection pin 19a of the cable portion 19 into the connection hole 71c.

[0053] 7, the electrode unit 48 and the connector unit 70 are connected via the connecting screws 69, and thus the electrode unit 48 is electrically connected to the detection unit 29a of the control board 29 via the cable unit 19. Furthermore, since the connector unit 70 is attached to the adapter member 40 with the gasket member 60 sandwiched therebetween, leakage of the transferred fluid does not infiltrate from the space 45 side of the adapter member 40 to the second wall surface 44b side of the wall portion 44.

[0054] 1, in the pump device 100 of the first embodiment, when the diaphragm 50 is damaged, the transported fluid leaks from the pump chamber 31 side into the space 45 side of the adapter member 40 and accumulates below as leaked liquid F. This changes the resistance value between the pair of electrodes 48 in the space 45, and the detection unit 29 a detects the presence of leaked liquid F based on this change, thereby detecting damage to the diaphragm 50.

[0055] Therefore, it is possible to use an inexpensive single-layer diaphragm 50 instead of an expensive multi-layer diaphragm. At the same time, the electrode portion 48 and the connector portion 70 can be formed inexpensively. Therefore, damage to the diaphragm 50 can be detected with an inexpensive configuration. The pair of electrodes 48 are arranged on the first wall surface 44a side in the shape of line symmetry plates as described above. The tip portions of the pair of electrodes 48 are guided by the guide frame 47a. Therefore, the distance between the electrodes can be accurately set, and the detection accuracy of changes in resistance value is high.

[0056] The electrode portion 48 has the shape described above, and is connected to the connector portion 70 in the positional relationship described above by the connecting screw 69 via the connecting hole portion 47 and the second hole portion 64. This structure ensures that the leaking liquid F that has accumulated in the space portion 45 will not leak out toward the second wall surface 44b before the leaking liquid F in the space portion 45 is detected.

[0057] [Second embodiment] Fig. 8 is a front view showing an adapter member attached to a pump body of a pump device according to a second embodiment of the present invention. Fig. 9 is a front view showing a drive mechanism housed in the pump body of the pump device. Fig. 10 is an enlarged cross-sectional view taken along line B-B' in Fig. 8. Fig. 11 is an explanatory diagram showing a second conductive member of the pump device, with Fig. 11(a) showing the front surface and Fig. 11(b) showing the top surface. Note that, in the following, explanations that overlap with those already explained will be omitted.

[0058] The pump device according to the second embodiment differs from the pump device 100 according to the first embodiment mainly in the structure of the second conductive member and the electrical connection between the second conductive member and the cable portion 19. The other basic configurations of the pump device according to the second embodiment are the same as those of the first embodiment. That is, the first embodiment employs a system in which the cable portion 19 is attached to the connector portion 70 attached to the adapter member 40. In contrast, the second embodiment employs a system in which the cable portion 19 is electrically connected to the electrode portion 48A simply by connecting the adapter member 40 to the bracket portion 15 of the drive mechanism 10 and attaching it to the pump body 20.

[0059] Therefore, unlike the first embodiment, there is no need to insert the connection pin 19a of the cable portion 19 into the connection hole 71c of the connector portion 70 to connect them before attaching the adapter member 40 to the pump body 20. To achieve this structure, in the second embodiment, as shown in Figures 11(a) and 11(b), the contact plate 70A, which is the second conductive member, is made of, for example, a metal material.

[0060] The contact plate 70A has a plate-shaped main body 71A and a leaf spring-shaped electrical contact portion 74. As shown in Fig. 10, the main body 71A presses the gasket member 60 against the second wall surface 44b of the wall portion 44 of the adapter member 40. The main body 71A also has insertion holes 76 through which the connection screws 69 are inserted. The main body 71A also has a pair of notches 75 that fit into positioning protrusions (not shown) formed on the gasket member 60 to position the contact plate 70A during installation.

[0061] The electrical contact portion 74 bends back from the main body portion 71A toward the pump main body 20 and, as shown in Figures 9 and 10, comes into elastic contact with the contacted screw 19b, which is the electrical connection portion of the cable portion 19. As shown in Figure 9, the cable portion 19 is pulled out from the housing space 21 of the pump main body 20 to the front side of the drive mechanism 10 through an outlet hole 15f provided in a part of the bracket portion 15 (the upper side in the illustrated example). A crimp terminal 19g is connected to the tip side of the cable portion 19. The cable portion 19 is terminated by connecting and fixing this crimp terminal 19g to a part of the bracket portion 15 via a rubber bushing 19f with the contacted screw 19b.

[0062] As shown in Fig. 8, the pair of electrodes 48A are arranged on the first wall surface 44a of the wall portion 44 of the adapter member 40, as in the first embodiment. However, the electrodes 48A do not have the insertion holes 48a as in the previous example, and are formed so that the front side is flat. Instead of the insertion holes 48a, the electrodes 48A are formed with insertion portions 77 having connecting member attachment holes 48Aa, as shown in Fig. 10.

[0063] A connection screw 69 inserted into the insertion hole 76 of the contact plate 70A is attached to the connection member attachment hole 48Aa from the second wall surface 44b side. Furthermore, the insertion portion 77 of the electrode portion 48A is inserted into the connection hole 47f formed in the wall portion 44 of the adapter member 40 from the first wall surface 44a side. Then, after the contact plate 70A and the gasket member 60 are attached from the second wall surface 44b side of the wall portion 44 of the adapter member 40, the connection screw 69 is attached to the connection member attachment hole 48Aa through the insertion hole 76 and the second hole portion 64a. This electrically connects and fixes the electrode portion 48A and the contact plate 70A.

[0064] Thereafter, the adapter member 40 shown in Fig. 8 is attached to the bracket portion 15 of the drive mechanism 10 shown in Fig. 9 as described above. Then, as shown in Fig. 10, the electrical contact portion 74 of the contact plate 70A comes into elastic contact with the contacted screw 19b. This electrically connects the electrode portion 48A to the control board 29 via the cable portion 19.

[0065] As described above, in the second embodiment, the cable portion 19 is electrically connected to the electrode portion 48A simply by attaching the adapter member 40 to the pump body 20. This eliminates the need for a separate connection of the cable portion 19, improving the ease of connecting the cable portion 19. At the same time, it is possible to improve the ease of assembly and maintenance of the pump device.

[0066] [Third embodiment] Fig. 12 is a front view showing an adapter member attached to a pump body of a pump device according to a third embodiment of the present invention. Fig. 13 is a front view showing a drive mechanism housed in the pump body of the pump device. Fig. 14 is an enlarged cross-sectional view taken along line CC' in Fig. 12. Fig. 15 is an explanatory diagram showing a second conductive member of the pump device, with Fig. 15(a) showing the front, Fig. 15(b) showing the bottom, and Fig. 15(c) showing the back.

[0067] The pump device according to the third embodiment differs from the pump device according to the second embodiment mainly in the manner of electrical connection between the second conductive member and the cable portion 19. The other basic configuration of the pump device according to the third embodiment is the same as that of the second embodiment. That is, in the second embodiment, the cable portion 19 is led out to the front side of the bracket portion 15 through the lead-out hole 15f of the bracket portion 15. The crimp terminal 19g at the tip end is connected and fixed to a part of the bracket portion 15 by the contact screw 19b via the rubber bushing 19f. In contrast, in the third embodiment, the cable portion 19 is electrically connected to the electrode portion 48A without being led out to the front side of the bracket portion 15 and fixed with the contact screw 19b.

[0068] Therefore, unlike the second embodiment, it is not necessary to route the cable portion 19 on the front side of the bracket portion 15 and then fasten the crimp terminal 19g of the cable portion 19 with the contacted screw 19b. This significantly improves assembly. In order to adopt this structure, in the third embodiment, as shown in Figures 15(a) to 15(c), the second conductive member is first a contact plate 70B made of, for example, a metal material similar to the contact plate 70A of the second embodiment.

[0069] Similar to the contact plate 70A, the contact plate 70B has a structure including a plate-shaped main body 71B and a leaf-spring-shaped electrical contact portion 74a. As shown in FIG. 14 , the main body 71B presses the gasket member 60 against the second wall surface 44b of the wall portion 44 of the adapter member 40. The main body 71B also has an insertion hole 76 through which the connection screw 69 is inserted, and a pair of notches 75. The function and effect of the pair of notches 75 are the same as those described above.

[0070] Like the electrical contact portion 74 of the contact plate 70A, the electrical contact portion 74a is formed so as to be curved back from the main body portion 71B toward the pump main body 20. The electrical contact portion 74a elastically contacts a metal bushing 79 (see FIG. 13) which is the electrical connection portion of the cable portion 19. As shown in FIG. 14, the metal bushing 79 has a shape that combines, for example, a disk-shaped contacted portion 79a and a cylindrical connecting portion 79b that stands upright from the center of the contacted portion 79a and has a smaller diameter than the contacted portion 79a and a connecting hole 79c formed inside.

[0071] 14 , the cable portion 19 having the connection pin 19a attached to its tip end is first inserted from the rear side (back surface side) of the bracket portion 15 into a mounting hole 15g formed in a part of the bracket portion 15 (in the illustrated example, horizontal to the central axis of the drive mechanism 10). Then, on the front side of the bracket portion 15, the cable portion 19 is connected to the metal bushing 79 by inserting the connection pin 19a into the connection hole 79c in the connection portion 79b of the metal bushing 79.

[0072] Next, a rubber bushing 19f is placed over the metal bushing 79, covering the entire surface from the rear side of the contacted portion 79a of the metal bushing 79 to the outer periphery of the connecting portion 79b. Then, the metal bushing 79 together with the rubber bushing 19f is inserted into the mounting hole 15g from the front side of the bracket portion 15, completing the attachment of the metal bushing 79 to the bracket portion 15 and the routing of the cable portion 19. The metal bushing 79 attached in this manner is electrically insulated from the bracket portion 15 (and the drive mechanism 10) by the rubber bushing 19f.

[0073] As described above, in the third embodiment, unlike the second embodiment, a method is adopted in which the connection pins 19a of the cable portion 19 are inserted into the connection holes 79c of the metal bushing 79 for connection. This eliminates the need to screw the contacted screws 19b into the bracket portion 15, improving assembly efficiency. In addition, the front side of the contacted portions 79a of the metal bushing 79 is flat. This provides a wider and larger contact surface than the contacted screws 19b, improving the reliability of the electrical connection with the electrical contact portions 74a of the contact plate 70B.

[0074] The manner in which the pair of electrode portions 48A are attached to the adapter member 40, the configuration thereof, and the manner in which the electrode portions 48A are connected to the contact plate 70B by attaching the adapter member 40 to the bracket portion 15 are the same as those in the second embodiment, and therefore will not be described here.

[0075] Although several embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims.

[0076] For example, in the above embodiment, the electrodes 48, 48A have an axisymmetrical plate shape that extends downward from the location corresponding to the connection hole 47 and curves along the inner circumferential wall surface 43a while approaching each other, as described above. The electrodes 48, 48A may have various other shapes as long as they are capable of contacting the leaked liquid F of the transported fluid within the space 45.

[0077] Furthermore, the connection between the connector portion 70 and the contact plates 70A and the cable portion 19 is not limited to the above-described manner as long as they are electrically connected to each other. In the above embodiment, the electrodes 48, 48A are electrically connected to the cable portion 19 via the connector portion 70 and the contact plates 70A, 70B. However, this is not limiting, and the cable portion 19 may be directly connected to the electrodes 48, 48A without going through the connector portion 70 and the contact plates 70A, 70B.

[0078] REFERENCE SIGNS LIST 10 Drive mechanism 11 Shaft member 20 Pump body 21 Storage space 30 Pump head 31 Pump chamber 40 Adapter member 43 Annular convex portion 43a Inner peripheral wall surface 44 Wall portion 44a First wall surface 44b Second wall surface 46 Central hole portion 47 Connection hole portion 48, 48A Electrode portion 50 Diaphragm 60 Gasket member 62 Central convex portion 63 First hole portion 64 Second hole portion 70 Connector portion 70A, 70B Contact plate 100 Pump device

Claims

a pump head having an inlet and an outlet for a transported fluid; a diaphragm attached to said pump head and forming a pump chamber communicating with said inlet and said outlet; a pump body including a reciprocating member connected to said diaphragm and movable in the reciprocating direction of said diaphragm, and a drive mechanism capable of driving said reciprocating member in the reciprocating direction of said diaphragm; an adapter member disposed between said pump head and said pump body, said adapter member including a pressing portion which sandwiches said diaphragm with said pump head, and a wall portion having a first wall surface which is continuous with an inner peripheral wall surface of said pressing portion and which forms a space on the back side of the diaphragm together with the inner peripheral wall surface of said pressing portion; a pair of first conductive members attached to the first wall surface side of said adapter member, whose lower ends are located at the lower end of the space and which face each other with a predetermined gap therebetween; and a cable portion electrically connected to each of the pair of first conductive members at a position above the lower end of the space. a detection unit that detects a change in resistance value between the pair of first conductive members through the cable portion and detects leakage of the transported fluid into the space portion.

2. A pump device as described in claim 1, further comprising a pair of second conductive members each connected to the pair of first conductive members at the upper position and at least a portion of which is arranged on a second wall surface side opposite the first wall surface of the wall portion of the adapter member and electrically connected to the cable portion, the cable portion being electrically connected to the pair of first conductive members via the pair of second conductive members.

3. The pump device according to claim 2, further comprising a gasket member attached to the second wall surface of the adapter member, wherein the adapter member has a central hole provided in the center of the wall portion, through which the reciprocating member is inserted in a liquid-tight manner via the gasket member, and a pair of connection holes provided in the wall portion surrounding the central hole, wherein the gasket member has a first hole through which the reciprocating member is inserted in a liquid-tight manner, and a pair of second holes provided at positions overlapping with the pair of connection holes of the adapter member, wherein the first conductive member extends downward from the pair of connection holes on the first wall surface side of the adapter member and extends toward each other along the inner wall surface toward a lower end of the space, and wherein the second conductive member is attached between the gasket member and the second wall surface of the wall portion of the adapter member, and is connected to the cable portion on the second wall surface side of the adapter member.

4. The pump device according to claim 3, wherein the pair of first conductive members are made of conductive resin or corrosion-resistant metal formed into a plate shape that is line-symmetrical with respect to a vertical axis passing through the central axis of the central hole.

5. The pump device according to claim 3, wherein the first conductive member and the second conductive member are connected via a connecting member that electrically connects them to each other.

6. The pump device as described in claim 5, wherein the second conductive member is made of conductive resin and has a main body having a plate-like portion that presses the gasket member against the second wall surface and a cylindrical portion in which a connection hole into which the electrical connection portion of the cable portion is inserted, a pair of claw portions that protrude from the plate-like portion of the main body and pass through the second hole portion and the connection hole portion to be hooked onto the first wall surface, and a cylindrical portion that is provided between the pair of claw portions and has a connection member mounting hole portion into which the connecting member is attached together with the first conductive member, and the first conductive member has an insertion hole through which the connecting member is inserted toward the connection member mounting hole portion.

7. The pump device described in claim 5, wherein the second conductive member is made of a metallic material and has a plate-shaped main body portion that presses the gasket member against the second wall surface and has an insertion hole through which the connecting member is inserted, and a leaf spring-shaped electrical contact portion that bends from the main body portion toward the pump body and contacts the electrical connection portion of the cable portion, and the first conductive member has a connection member mounting hole portion to which the connecting member inserted into the insertion hole is attached.

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