JP7128093B2 - reciprocating pump - Google Patents

Description

This specification discloses a reciprocating pump that sucks and discharges liquid by reciprocating a diaphragm facing a pump chamber.

2. Description of the Related Art A reciprocating pump that sucks and discharges liquid by reciprocating a diaphragm facing a pump chamber has been widely known. Such reciprocating pumps are widely used for dosing chemical liquids because they can achieve quantitative performance. However, in such a reciprocating pump, if gas is mixed in the liquid to be handled, the expansion and compression of this gas may reduce the pumping action or even stop it.

Therefore, conventionally, it has been proposed to provide a reciprocating pump with a gas vent valve (for example, Patent Document 1, etc.). A gas release valve is a valve that releases gas accumulated near a discharge valve provided in the middle of a discharge flow path to the outside. This degassing valve is generally screwed into a degassing passage that communicates with the discharge valve. When it is tightened, communication between the discharge valve and the outside is cut off, and when it is loosened, the discharge valve communicates with the outside. When a large amount of gas accumulates near the discharge valve, the gas can be released to the outside by loosening the gas vent valve.

JP 2010-127273 A

Here, as described above, in order to release the gas, it is necessary to loosen the gas vent valve, that is, to rotate the gas vent valve in one direction. was not provided. Therefore, the gas vent valve may be rotated (loosened) more than necessary, and the gas vent valve may come off from the pump head. In this case, there is a possibility that a large amount of liquid may leak from the gas vent channel.

Accordingly, the present specification discloses a reciprocating pump that can prevent unintentional disengagement of the gas vent valve.

A reciprocating pump disclosed in this specification is a reciprocating pump that sucks and discharges a fluid by reciprocating a diaphragm facing a pump chamber, and includes a suction passage and a discharge passage communicating with the pump chamber, and the discharge a pump head having a gas vent passage communicating with the passage formed therein; and a gas that is screwed into the gas vent passage and is tightened or loosened to block or allow communication between the discharge passage and the external space. A vent valve and a stop mechanism for limiting the amount of rotation of the gas vent valve in the loosening direction are provided . a base surface of the pump head axially facing the support plate; a valve-side projecting portion projecting from the support plate toward the base surface; and a head-side protrusion that, when the gas vent valve reaches a specific rotational position, abuts against the valve-side protrusion to limit further rotation of the gas vent valve, wherein the valve-side protrusion At least one of the portion and the head-side projecting portion is elastically displaceable in the axial direction of the gas vent valve so as to get over the other .

A reciprocating pump disclosed in this specification is a reciprocating pump that sucks and discharges a fluid by reciprocating a diaphragm facing a pump chamber, and includes a suction passage and a discharge passage communicating with the pump chamber, and the discharge a pump head having a gas vent passage communicating with the passage formed therein; and a gas that is screwed into the gas vent passage and is tightened or loosened to block or allow communication between the discharge passage and the external space. A vent valve and a stop mechanism for limiting the amount of rotation of the gas vent valve in the loosening direction are provided. a base surface of the pump head axially facing the support plate; a valve-side projecting portion projecting from the support plate toward the base surface; and a head-side protrusion that, when the gas vent valve reaches a specific rotational position, abuts against the valve-side protrusion to limit further rotation of the gas vent valve, wherein the valve-side protrusion When the gas vent valve is rotated in the loosening direction, one circumferential end surface of each of the valve-side projecting portion and the head-side projecting portion functions as a loosening-side end surface that contacts the other side, and the valve-side projecting portion and the head-side projecting portion The opposite side end face in the circumferential direction functions as a tightening side end face that contacts the other when the gas vent valve is rotated in the tightening direction, and the inclination angle of the loosening side end face is larger than the inclination angle of the tightening side end face , close to the axial angle of the vent valve .

In this case, at least one of the valve-side projecting portion and the head-side projecting portion may be elastically displaceable in the axial direction of the gas vent valve so as to get over the other.

In addition, the support plate has a thickness that allows it to bend in the axial direction of the gas vent valve. good too.

Further, the support plate may have a cantilever shape with only its radial base connected to the gas vent valve.

In addition, the head-side protrusion has a cantilever-like arm portion that is connected to the base surface at only one end in the circumferential direction thereof, and a tip portion that abuts on the valve-side protrusion, and the pump head A portion adjacent to the arm portion in the axial direction may be provided with a notch to allow the arm portion to swing in the axial direction.

Further, the amount of rotation of the gas vent valve in the direction of loosening required for switching from a state in which the discharge passage and the outside are blocked to a state in which they are communicated may be less than one rotation.

According to the reciprocating pump disclosed in this specification, the amount of rotation of the gas vent valve in the loosening direction is limited, so that unintended disengagement of the gas vent valve can be prevented.

Fig. 3 is a cross-sectional view of a pump head of a reciprocating pump; It is a perspective view around a stop mechanism. It is the figure which looked at the stop mechanism from directly above. It is a schematic diagram which shows a motion of a stop mechanism. It is a perspective view around another stop mechanism. 4 is a schematic cross-sectional view of the stop mechanism of FIG. 3; FIG. It is a perspective view around another stop mechanism. It is the figure which looked at the stop mechanism of FIG. 7 from directly above. It is a schematic diagram which shows a motion of a stop mechanism.

The configuration of the reciprocating pump 10 will be described below with reference to the drawings. FIG. 1 is a cross-sectional view of a reciprocating pump 10. FIG. The reciprocating pump 10 has a pump head 12 through which a target fluid flows, and a drive section (not shown) that reciprocates a diaphragm 16 facing a pump chamber 18 . The pump head 12 is a disc-shaped or elliptical plate-shaped member whose thickness direction is substantially horizontal. A concave portion 14 is formed at one end of the pump head 12 in the thickness direction. This recess 14 is covered with a diaphragm 16 made of a flexible material. A pump chamber 18 is formed between the diaphragm 16 and the recess 14 .

A horizontally extending shaft 17 is connected to the diaphragm 16 . The drive unit is provided with a mechanism for horizontally reciprocating the shaft. For example, an electromagnetic plunger or the like can be used as the mechanism of such a drive unit. Since conventional technology can be used for the configuration of such a driving unit, detailed description thereof will be omitted here.

The pump head 12 further includes a common channel 20 extending horizontally from the pump chamber 18, a suction channel 22 extending substantially vertically from the lower end of the pump head 12 toward the common channel 20, and a suction channel 22 extending from the common channel 20 to the pump head. 12, and a gas release passage 30 communicating with the discharge passage 24 (more precisely, the discharge valve 34) are provided. A suction valve 32 , which is a check valve, is provided in the middle of the suction passage 22 to allow only the flow from the suction port 26 toward the common passage 20 . Further, in the middle of the discharge passage 24, a discharge valve 34, which is a check valve that allows only the flow from the common passage 20 toward the discharge port 28, is provided. The degassing passage 30 is a passage that communicates with the discharge passage 24 , more precisely the side surface of the discharge valve 34 .

A boss 31 projecting horizontally is formed at the other end in the thickness direction of the pump head 12 . A valve insertion hole 33 communicating with the gas release passage 30 extends horizontally from the end face of the boss 31 . A female screw is formed on the inner peripheral surface of the valve insertion hole 33 .

The gas vent valve 40 is a valve that is screwed into the valve insertion hole 33 and switches communication/blocking between the discharge passage 24 and the external space. Inside the gas vent valve 40, a small hole 42 radially extending from the peripheral surface of the gas vent valve 40 and a discharge passage 44 axially extending from the small hole 42 to the outside are formed. O-ring gases 46a and 46b are provided between the gas vent valve 40 and the valve insertion hole 33, and when the gas vent valve 40 is completely closed, the discharge passage 24 and the external space are completely blocked. be. On the other hand, when the gas vent valve 40 is loosened appropriately, the discharge passage 24 and the external space are communicated with each other through the valve insertion hole 33, the gas vent passage 30, the small hole 42, and the discharge passage 44.

The operation of the reciprocating pump 10 having the above configuration will be briefly described. When the diaphragm 16 retreats (moves rightward in FIG. 1) and the pump chamber 18 expands, the discharge valve 34 is closed and the suction valve 32 is opened. As a result, the target fluid flows into the pump chamber 18 from the suction port 26 . Further, when the diaphragm 16 advances and the pump chamber 18 is compressed, the suction valve 32 is closed and the discharge valve 34 is opened. As a result, the target fluid in the pump chamber 18 is discharged outside through the discharge passage 24 . By repeating the movement of the diaphragm 16 as described above, the target fluid is pressure-fed.

By the way, the target fluid usually contains gas such as air. If such gas stays under the discharge valve 34, the expansion and compression of the gas reduces the pump action and may even stop it. That is, when the gas remains below the discharge valve 34, even if the pump chamber 18 is compressed, part of the force is used to compress the gas, making it difficult to discharge the target liquid. Further, even if the pump chamber 18 is expanded thereafter, part of the force is used to expand the gas, making it difficult for the target liquid to be sucked. In some cases, expansion and compression of the pump chamber 18 only expands and compresses the retained gas, causing gas lock in which the target liquid is not discharged and sucked.

The gas vent valve 40 is provided to prevent such gas lock. When the gas vent valve 40 is loosened, the discharge passage 24 and the external space are communicated, and the stagnant gas is released to the external space. Here, in order to release the gas, it is sufficient to form a slight gap between the gas vent valve 40 and the O-ring 46a, and the gas vent valve 40 need not be excessively loosened. However, conventionally, it has been difficult for the user to know the appropriate loosening amount of the gas vent valve 40 . As a result, the user may accidentally loosen the gas vent valve 40 excessively and completely remove the gas vent valve 40 from the valve insertion hole 33 . When the gas vent valve 40 is removed from the valve insertion hole 33, problems such as leakage of a large amount of the target fluid are caused.

Therefore, in this example, a stop mechanism 50 is provided to prevent excessive loosening of the gas vent valve 40 . This will be described with reference to FIGS. 2 to 4. FIG. FIG. 2 is a perspective view around the gas vent valve 40. FIG. Moreover, FIG. 3 is the figure which looked at the gas vent valve 40 from right above. 4A and 4B are schematic diagrams showing the movement of the stop mechanism 50. FIG. In addition, the axial direction, the radial direction, and the circumferential direction in the following description mean the axial direction, the radial direction, and the circumferential direction of the gas vent valve 40 unless otherwise specified.

In this example, the amount of rotation of the degassing valve 40 in the loosening direction required to switch from the closed state in which the discharge passage 24 and the external space are blocked to the open state in which they communicate is 180 degrees, 1/2 rotation. Therefore, the pitch of the male screw of the gas vent valve 40 is set so that it can be shifted to the open state by 1/2 rotation. In this example, the male and female threads formed in the gas vent valve 40 and the valve insertion hole 33 are double threads so that a larger forward/backward distance can be obtained than the amount of rotation.

As described above, a substantially cylindrical boss 31 protrudes from the end face of the pump head 12 . A valve insertion hole 33 extending in the axial direction is formed in the center of this boss 31 , and a gas vent valve 40 is screwed into the valve insertion hole 33 . A head portion 48 of the gas vent valve 40 is exposed outside the boss 31 .

In the middle of the head portion 48 of the gas vent valve 40, a substantially disc-shaped flange portion 49 projecting radially outward is provided. A portion of this flange portion 49 is reduced in thickness to such an extent that it is bent in the axial direction of the gas vent valve 40 . The part from which the thickness has been reduced becomes the support plate 52 . The valve-side protrusion 54 protrudes from the support plate 52 toward the boss 31 . As shown in FIG. 3, the valve-side projecting portion 54 has a substantially triangular shape when viewed from above. In other words, both circumferential ends of the valve-side projecting portion 54 are inclined with respect to the axial direction. More specifically, of the circumferential ends of the valve-side projecting portion 54, the loosening-side end face 54a, which is the end face in the direction in which the gas vent valve 40 is loosened (upper side of the paper surface in FIG. 3), is slightly inclined with respect to the axial direction. Inclined. On the other hand, of the circumferential ends of the valve-side projecting portion 54, a tightening-side end surface 54b, which is an end surface on the tightening direction side of the gas vent valve 40 (lower side of the paper surface in FIG. 3), is greatly inclined with respect to the axial direction. . That is, in this example, the inclination angle of the loosening side end face 54a is closer to the axial angle of the gas vent valve 40 than the inclination angle of the tightening side end face 54b.

An axial end surface of the boss 31 serves as a base surface 60 facing the support plate 52 . The base surface 60 is provided with a head-side protrusion 62 that protrudes toward the support plate 52 . The head-side projecting portion 62 also has a substantially triangular shape when viewed from above. More specifically, of the axial ends of the head-side projecting portion 62, the loosening-side end surface 62a on the loosening side when viewed from the valve-side projecting portion 54 is slightly inclined with respect to the axial direction. On the other hand, of the head-side projecting portion 62, the tightening-side end surface 62b on the tightening side when viewed from the valve-side projecting portion 54 is inclined largely by 45 degrees or more with respect to the axial direction. That is, even in the head-side projecting portion 62, the inclination angle of the loosening side end face 62a is closer to the axial angle of the gas vent valve 40 than the inclination angle of the tightening side end face 62b.

The stop mechanism 50 that limits the amount of rotation of the gas vent valve 40 in the loosening direction includes the above-described support plate 52 , valve-side protrusion 54 , base surface 60 , and head-side protrusion 62 . When the gas vent valve 40 is closed completely, the valve-side projecting portion 54 is shifted from the head-side projecting portion 62 by 180 degrees or more in the circumferential direction. When the head-side projecting portion 62 is rotated in the loosening direction from this state, the degassing passage 30 is opened. When the gas vent valve 40 is to be rotated more than a certain amount, the loosening side end surface 54a of the valve-side projecting portion 54 hits the loosening-side end surface 62a of the head-side projecting portion 62 as shown in FIG. 4(a). touch. This restricts further rotation of the gas vent valve 40 in the loosening direction. This effectively prevents unintentional removal of the gas vent valve 40 .

By the way, the gas vent valve 40 needs to be removed from the pump head 12 for maintenance. Therefore, if the user intends, the valve-side projecting portion 54 is arranged so that the gas vent valve 40 can be removed from the pump head 12. In this example, the valve-side projecting portion 54 can climb over the head-side projecting portion 62. It can be elastically displaced in the axial direction. Specifically, in this example, the support plate 52 on which the valve-side projecting portion 54 is installed is made thin enough to bend in the axial direction. By pushing and bending the support plate 52 in the axial direction away from the base surface 60 as shown in , the valve-side projecting portion 54 is elastically displaced in the axial direction. When the gas vent valve 40 is rotated in the loosening direction while the support plate 52 is bent, the valve-side projecting portion 54 can get over the head-side projecting portion 62 . By continuing this work, the valve-side projecting portion 54 can be removed from the valve insertion hole 33 .

When assembling the gas vent valve 40 into the valve insertion hole 33, the gas vent valve 40 is inserted into the valve insertion hole 33 and then rotated in the tightening direction. Along with this rotation, the tightening-side end surface 54b of the valve-side protrusion 54 comes into contact with the tightening-side end surface 62b of the head-side protrusion 62, as shown in FIG. 4(b). In this case also, the valve-side projecting portion 54 can get over the head-side projecting portion 62 by bending the support plate 52 in the direction away from the base surface 60 . The rotation of the valve-side projecting portion 54 needs to be restricted in the loosening direction, but does not need to be particularly restricted in the tightening direction. Therefore, in this example, the angle of inclination of the tightening side end surfaces 54b, 62b is increased so that most of the circumferential force applied to the tightening side end surfaces 54b, 62b is converted into axial force. As a result, when the gas vent valve 40 is assembled, the valve-side projecting portion 54 can climb over the head-side projecting portion 62 by turning the gas vent valve 40 strongly in the tightening direction without pressing the support plate 52 with fingers. . As a result, the assembly work of the gas vent valve 40 can be simplified.

As is clear from the above description, according to this example, the amount of rotation of the gas vent valve 40 in the loosening direction is appropriately limited. As a result, unintended detachment of the gas vent valve 40 can be prevented.

Next, another form of the stop mechanism 50 will be described. FIG. 5 is a perspective view of a gas vent valve 40 having another stop mechanism 50. FIG. 6 is a schematic cross-sectional view around the valve-side projecting portion 54. As shown in FIG. Also in this form, the stop mechanism 50 has a support plate 52 , a valve-side protrusion 54 , a base surface 60 , and a head-side protrusion 62 . However, in this example, notches 63 are formed at both circumferential ends of the support plate 52 to separate the support plate 52 and the flange portion 49 . In other words, the support plate 52 has a cantilever shape that is connected to the gas vent valve 40 only on the radial root side.

With such a configuration, the support plate 52 can be more easily bent as shown in FIG. As a result, the support plate 52 can be bent without applying a large force to the support plate 52, and the removal and assembly of the gas vent valve 40 can be performed more easily.

Next, another stop mechanism 50 will be described with reference to FIGS. 7 to 9. FIG. FIG. 7 is a perspective view of another stop mechanism 50 and its surroundings. 8 is a view of the stop mechanism 50 as seen from directly above. Further, FIG. 9 is a schematic diagram showing movement of the stop mechanism 50. As shown in FIG.

In the description so far, the valve-side projecting portion 54 provided on the gas vent valve 40 can be elastically displaced, but in this example, the head-side projecting portion 62 provided on the pump head 12 can be elastically displaced in the axial direction. I'm trying Specifically, in this example, the flange portion 49 functions as the support plate 52 , and the valve-side projecting portion 54 projects from the flange portion 49 (support plate 52 ) toward the base surface 60 .

The head-side projecting portion 62 has a cantilever-like arm portion 64 connected to the base surface 60 at only one end in the circumferential direction, and a distal end portion 66 provided at the distal end of the arm portion 64 . A notch 68 is provided at a portion of the pump head 12 adjacent to the arm portion 64 in the axial direction so as to allow the arm portion 64 to swing in the axial direction. The distal end portion 66 is a portion that contacts the valve-side projecting portion 54, and has a loosening side end face 62a slightly inclined with respect to the axial direction and a tightening side end face 62b greatly inclined with respect to the axial direction. is doing.

In this case as well, when the gas vent valve 40 is rotated in the loosening direction from the closed state, as shown in FIG. It abuts against the end face 62a, thereby preventing excessive loosening of the vent valve 40. As shown in FIG.

When removing the gas vent valve 40 for maintenance or the like, the user pushes the arm portion 64 of the head-side projecting portion 62 away from the support plate 52 to swing it. By further rotating the gas vent valve 40 in this state in the loosening direction, the valve-side projecting portion 54 can easily get over the head-side projecting portion 62 . And thereby, the gas vent valve 40 can be removed easily.

When the gas vent valve 40 that has been removed once is assembled into the valve insertion hole 33, the gas vent valve 40 may be inserted into the valve insertion hole 33 and rotated in the tightening direction. At this time, since the tightening-side end surface 62b of the head-side projection 62 is greatly inclined with respect to the axial direction, as shown in FIG. is converted in the axial direction, and the arm portion 64 swings in the axial direction. As a result, the valve-side projecting portion 54 can climb over the head-side projecting portion 62 without pressing the arm portion 64 with a finger.

As described above, by providing the stop mechanism 50 that limits the amount of rotation of the gas vent valve 40 in the loosening direction, unintended removal of the gas vent valve 40 can be prevented. At least one of the valve-side projecting portion 54 and the head-side projecting portion 62 can be elastically displaced in the axial direction, so that the degassing valve 40 can be removed and assembled as necessary.

Note that the configuration described so far is only an example, and other configurations may be appropriately changed as long as at least the stop mechanism 50 that limits the amount of rotation of the degassing valve 40 in the loosening direction is provided. For example, in the above description, only one of the valve-side projecting portion 54 and the head-side projecting portion 62 is configured to be elastically displaceable in the axial direction, but both may be elastically displaceable in the axial direction. Thus, for example, the gas vent valve 40 may be provided with an axially flexible support plate 52 and the pump head 12 may be provided with a head-side projection 62 including an arm portion 64 .

Also, in this example, the amount of rotation required from the closed state to the open state is 1/2 rotation, but this amount of rotation may be changed as appropriate as long as it is less than one rotation. Further, the shapes of the head-side projecting portion 62 and the valve-side projecting portion 54 may be changed as appropriate. Therefore, the valve-side protruding portion 54 and the head-side protruding portion 62 may be, for example, semicircles that are convex toward the other side when viewed from above.

10 reciprocating pump, 12 pump head, 14 recess, 16 diaphragm, 17 shaft, 18 pump chamber, 20 common passage, 22 suction passage, 24 discharge passage, 26 suction port, 28 discharge port, 30 gas release passage, 31 boss, 32 suction valve, 33 valve insertion hole, 34 discharge valve, 40 gas vent valve, 42 small hole, 44 discharge passage, 46 O-ring, 48 head, 49 flange, 50 stop mechanism, 52 support plate, 54 valve side protrusion Part, 54a, 62a loosening side end surface, 54b, 62b tightening side end surface, 60 base surface, 62 head side projecting portion, 63 notch, 64 arm portion, 66 tip portion, 68 notch.

Claims (7)

A reciprocating pump that sucks and discharges a fluid by reciprocating a diaphragm facing a pump chamber,
a pump head having therein a suction passage and a discharge passage communicating with the pump chamber, and a degassing passage communicating with the discharge passage;
a gas vent valve that is screwed into the gas vent passage and is tightened or loosened to cut off or allow communication between the discharge passage and the external space;
a stop mechanism that limits the amount of rotation of the gas vent valve in the loosening direction;
with
The stop mechanism is
a support plate projecting radially outward from the peripheral surface of the gas vent valve outside the pump head;
a base surface of the pump head axially facing the support plate;
a valve-side projecting portion projecting from the support plate toward the base surface;
A head-side protrusion projecting from the base surface toward the support plate and restricting further rotation of the gas vent valve by abutting against the valve-side protrusion when the gas vent valve reaches a specific rotational position. When,
with
At least one of the valve-side projecting portion and the head-side projecting portion is elastically displaceable in the axial direction of the gas vent valve so as to overcome the other.
A reciprocating pump characterized by: A reciprocating pump that sucks and discharges a fluid by reciprocating a diaphragm facing a pump chamber,
a pump head having therein a suction passage and a discharge passage communicating with the pump chamber, and a degassing passage communicating with the discharge passage;
a gas vent valve that is screwed into the gas vent passage and is tightened or loosened to cut off or allow communication between the discharge passage and the external space;
a stop mechanism that limits the amount of rotation of the gas vent valve in the loosening direction;
with
The stop mechanism is
a support plate projecting radially outward from the peripheral surface of the gas vent valve outside the pump head;
a base surface of the pump head axially facing the support plate;
a valve-side projecting portion projecting from the support plate toward the base surface;
A head-side protrusion projecting from the base surface toward the support plate and restricting further rotation of the gas vent valve by abutting against the valve-side protrusion when the gas vent valve reaches a specific rotational position. When,
with
One circumferential end surface of each of the valve-side projecting portion and the head-side projecting portion functions as a loosening-side end surface that contacts the other when the gas vent valve is rotated in a loosening direction,
Circumferentially opposite end surfaces of the valve-side projecting portion and the head-side projecting portion function as tightening-side end surfaces that contact the other when the gas vent valve is rotated in the tightening direction,
The inclination angle of the loosening side end face is closer to the axial angle of the gas vent valve than the inclination angle of the tightening side end face,
A reciprocating pump characterized by: A reciprocating pump according to claim 2,
A reciprocating pump, wherein at least one of the valve-side projecting portion and the head-side projecting portion is elastically displaceable in the axial direction of the gas vent valve so as to ride over the other. A reciprocating pump according to claim 1 or 3,
The support plate has a thickness that allows it to bend in the axial direction of the gas vent valve,
By bending the support plate, the valve-side projecting portion climbs over the head-side projecting portion,
A reciprocating pump characterized by: A reciprocating pump according to claim 4,
A reciprocating pump according to claim 1, wherein the support plate is formed in a cantilever beam shape with only a radial base thereof connected to the gas vent valve. A reciprocating pump according to claim 4 or 5 ,
The head-side projecting portion has a cantilever-like arm portion that is connected to the base surface at only one end in the circumferential direction, and a tip portion that contacts the valve-side projecting portion,
A portion of the pump head adjacent to the arm portion in the axial direction is provided with a notch to allow the arm portion to swing in the axial direction.
A reciprocating pump characterized by: A reciprocating pump according to any one of claims 1 to 6 ,
A reciprocating pump according to claim 1, wherein the amount of rotation of said degassing valve in the loosening direction required for switching from a state in which said discharge passage and the outside are disconnected to a state in which they are communicated is less than one turn.

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