JPS6135750Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a reciprocating pump using bellows.

In this type of reciprocating pump, one end of the bellows is fixed facing the pump casing, the other end of the bellows is connected to a reciprocating body such as a piston, and the suction hole and discharge hole formed in the pump casing are connected to the bellows. One end is opened facing the opening, and the bellows is expanded and contracted by a reciprocating body to suck fluid into the bellows from the suction hole.
The purpose is to discharge the fluid inside the bellows from the discharge hole and transfer it quantitatively.

However, in this type of pump, in order to transfer fluid quantitatively, it is necessary to
That is, it is necessary to regulate the reciprocating stroke to be constant and to draw a certain amount of fluid into the bellows and discharge it. To do this, the driving side end of the bellows connected to the reciprocating body is stopped at a constant compression end position when the bellows is compressed, and the driving side end of the bellows is moved from this constant compression end position by the reciprocating body. It is necessary to move the bellows to a certain extension end position and make the reciprocating stroke of the bellows constant.

However, conventional pumps are not provided with any means for regulating and stopping the drive end of the bellows at a predetermined compression end position. For this reason, the drive side end of the bellows is not forcibly stopped at a fixed compression end position when the bellows is compressed, but stops in an unstable state, so the stopping position changes and it stops at a fixed compression position. There are things I can't do. Therefore, there was a problem in that the reciprocating stroke of the bellows could not be regulated at a constant level, and the amount of fluid transferred varied, making it impossible to transfer the fluid quantitatively.

In addition, in a bellows pump, if the volume of the gap (clearance volume) between the bellows driving side end and the pump casing, that is, the volume of the internal space of the bellows (dead volume), is large, small gases may remain in the fluid to be transferred or may enter. As a result, the actual discharge amount decreases and quantitative performance deteriorates. Therefore, it is necessary to reduce the volume within the bellows. However, conventional bellows pumps are not provided with any means for reducing the volume within the bellows, and this also poses a problem in terms of quantitative performance.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a bellows-type reciprocating pump that has a simple structure and improves the quantitative performance of fluid transfer by the bellows.

Embodiments of the present invention will be described below with reference to drawings.

In the figure, 1 is a disk-shaped pump casing, and this pump casing 1 has a suction hole 2 and a discharge hole 3, respectively.The suction hole 2 has a suction port unit 4, and the discharge hole 3 has a An outlet unit 5 is provided in each case. Suction port unit 4 and discharge port unit 5
A connecting tube 6, a holding nut 7 for holding the connecting tube 6 on the pump casing 1, and a ball-shaped check valve 8 provided on the pump casing 1 inside the connecting tube 6 are provided. Check valve 8 of suction port unit 4
The check valve 8 of the discharge port unit 5 allows the fluid to flow only in the suction direction and prevents the fluid from flowing in the opposite direction, and the check valve 8 of the discharge port unit 5 allows the fluid to flow only in the discharge direction and prevents the fluid from flowing in the opposite direction. . 9 in the figure is a bellows having pleats 9a. This bellows 9
One open end 9b is in contact with the center of one side of the pump casing 1 and is fixed by a fixing plate 10, and the other open end 9c is in contact with the center of one side of the pump casing 1.
It is closed by a closing plate 12 via the closing plate 12, and is held by the closing plate 12 and a mounting plate 13. Note that the closing plate 12 is screwed into the ring body 14 holding down the mounting plate 13. In the figure, reference numeral 15 denotes a reciprocating body made of, for example, a piston, which is reciprocated by an appropriate reciprocating drive device (not shown).

Furthermore, a cylindrical protrusion 17 is formed in the center of one side of the pump casing 1 so as to extend laterally. The protrusion 17 is inserted into the inner space of the bellows 9 from the opening 9b of the bellows 9 along its central axis, and has a length corresponding to the length of the bellows 9 when it is compressed. It has an outer diameter smaller than the inner diameter. For this reason, the bellows 9 is provided to surround the protrusion 17. Further, when the bellows 9 is compressed, the seal plate 11 attached to the other end of the bellows 9 comes into contact with the end surface of the tip end of the protrusion 17. Also,
The circulation hole 18 , which is an inner hole formed on the internal central axis of the protrusion 17 , has one end extending to the center of the interior of the pump casing 1 and connected to the suction hole 2 , and the other end extending to the tip of the protrusion 17 . It is open at the end surface. An annular groove 19 is formed on one side of the pump casing 1 surrounding the proximal end of the protrusion 17, and a part of the annular groove 19 has the discharge hole 3 of the pump casing 1 extended therethrough. It's open.

In addition, 20 in the figure is a support base that supports the pump casing 1 and the reciprocating body 15.

In this bellows-type reciprocating pump, when the reciprocating drive device is driven to reciprocate the reciprocating body 15, the other end 9c of the bellows 9 is moved by the driving force of the reciprocating body 15 via the closing plate 12 and the mounting plate 13. The entire bellows 9 expands and contracts. First, when the reciprocating body 15 moves in the A direction (extension direction) with a predetermined stroke, the other end 9c of the bellows 9 is pulled in the same direction and moves to a predetermined extension position, so that the bellows 9 is extended. in this case,
The seal plate 11 provided at the other end 9c of the bellows 9 moves away from the end surface of the tip end of the protrusion 17 by a predetermined stroke, and the communication hole 18 opens. Therefore, the internal space of the bellows 9 becomes a negative pressure, and a certain amount of the fluid to be transferred, such as photoresin, is sucked into the suction hole 2 of the pump casing 1 via the connection tube 6 of the suction port unit 4 and the check valve 8. Further, the fluid passes through the communication hole 18 of the protrusion 17 and flows into the portion surrounding the protrusion 17 in the internal space of the bellows 9 . Next, when the reciprocating body 15 moves in the B direction (compression direction) with a predetermined stroke, the bellows 9
The other end 9c is pushed and moved in the same direction, and the entire bellows 9 is compressed. In this case, the seal plate 11 provided on the other end 9c of the bellows 9 comes into contact with the end surface of the tip end of the protrusion 17, and the movement of the other end 9c of the bellows 9 is stopped, and the seal plate 11 is attached to the protrusion 17. The opening of the communication hole 18 is closed. bellows 9
The fluid sucked into the internal space is pressurized by the bellows 9 and is discharged in a fixed amount outward from the discharge hole 3 of the pump casing 1 through the check valve 8 of the discharge port unit 5. The amount of fluid transferred, that is, the amount of suction and the amount of discharge, are determined by the length of extension and contraction of the bellows 9, that is, the reciprocating stroke, and the fluid is transferred quantitatively.

Therefore, in the operation of the pump described above, when the bellows 9 is compressed, the driving side end of the bellows 9 connected to the reciprocating body 15 comes into contact with the end surface of the tip end of the protrusion 17, so that the bellows 9 is stopped at a certain compression end position. be done. Therefore, the bellows 9 performs the expansion and contraction operation while regulating the compression end position to a constant value, so that the length of expansion and contraction of the bellows 9, that is, the reciprocating stroke can be regulated to a constant value. Further, when the drive side end of the bellows 9 comes into contact with the end surface of the tip end of the protrusion 17,
The communication hole 18 of the protrusion 17 is closed. Therefore, the fluid can be constantly sucked in and discharged in a fixed amount by the expansion and contraction motion of the bellows 9, and can be transferred quantitatively.

In addition, by providing the cylindrical protrusion 17 having the flow hole 18 inside the bellows 9, the volume inside the bellows 9 is reduced, so that the actual discharge amount of the fluid is not decreased, and a quantitative amount of fluid can be delivered. Can be transferred.

Furthermore, in order to prevent the fluid discharged from the connecting tube 6 of the discharge unit 5 from dripping from the injection tip into other equipment, a bypass circuit can be provided to send part of the fluid from the discharge hole side to the suction hole side as shown in the drawing. That is, the suction hole 2 of the pump casing 1 is extended to the other side, and a flow control valve, for example a needle valve 21, is provided on the other side of the pump casing 1, connected to the suction hole 2. A branch pipe 22 is provided on the connecting tube 6 of the discharge unit 5.
The needle valve 21 has a needle 24 at a right angle to a connecting pipe 23 connected to the suction hole 2.
The tip of the needle 24 is inserted into the flow pipe 23. The position of the needle 24 can be adjusted by an adjustment member 25. The flow pipe 23 is connected to the branch pipe 22 via a bypass pipe.
A part of the fluid discharged from the pump casing 1 returns to the flow hole 18 of the pump casing 1 via the needle valve 21.
Dripping of fluid can be prevented.

In addition, in the above-described embodiment, the protruding part is formed integrally with the pump casing, but the present invention is not limited to this, and the protruding part may be formed separately and fixed to the pump casing. Further, the bypass circuit described above does not necessarily need to be provided.

As explained above, according to the bellows-type reciprocating pump of the present invention, when the bellows is compressed, the driving side end of the bellows is brought into contact with the end face of the tip of the protruding part of the pump casing, and is kept at a constant compression end position. By stopping the bellows, the reciprocating stroke of the bellows is regulated to a constant level, and when the bellows is compressed, the driving side end of the bellows closes the flow hole of the protrusion, thereby transferring a fixed amount of fluid and discharging the sulfur. Quantitative transfer can be improved. Furthermore, by providing a cylindrical protrusion having a flow hole inside the bellows, the volume inside the bellows can be reduced and the quantitative nature of fluid transfer can be improved.

[Brief explanation of the drawing]

The drawing is a longitudinal sectional view showing an embodiment of the reciprocating pump of the present invention. 1...Pump casing, 2...Suction hole, 3...
...Discharge hole, 4...Suction port unit, 5...Discharge port unit, 9...Bellows, 15...Reciprocating body,
17... Protrusion, 18... Communication hole, 21... Needle valve.

Claims (1)

[Scope of utility model registration request] A pump casing having a cylindrical protrusion in which a suction hole and a discharge hole for the fluid to be transferred are formed, and a circulation hole communicating with the suction hole, and the discharge hole is opened around the proximal end of the protrusion. and,
It is provided around the protrusion and has an opening at one end that communicates with the opening of the discharge hole and is fixed to the pump casing, and a closed part at the other end that comes into contact with the end surface of the tip of the protrusion to close the flow hole. a bellows that moves between a compressed end position that closes the bellows and an extended end position that is away from the end face of the distal end of the protrusion, and a reciprocating body that is connected to the other end closing portion of the bellows and causes the bellows to expand and contract. Bellows type reciprocating pump.