JPH018672Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is a reciprocating pump that utilizes the pulsating flow that occurs within the pressure chamber of the fluid during the pump's discharge stroke and suction stroke to release the air present in the pressure chamber. This invention relates to a drain valve device.

In a reciprocating pump, the fluid to be discharged is sent out quantitatively from the pump chamber as a reciprocating member such as a plunger operates, and the pulsating flow within the fluid that occurs over the discharge stroke and suction stroke of this fluid is utilized. An air bleed valve device is generally known that discharges mixed air from a pump chamber serving as a pressure chamber to the outside. Such a valve device is provided in communication with a pressure chamber, but in the case of a reciprocating pump or a hydraulic diaphragm type metering pump, a valve device connected to a hydraulically driven chamber that also forms a pressure chamber is provided outside the pump chamber. This improves the metering accuracy of the pump and prevents a decrease in the amount of fluid discharged, or prevents a state in which fluid cannot be discharged.

As a conventional example of such an air bleed valve device, the first
In the figure, the valve device 1 is connected to a hydraulic drive chamber 2 forming a pressure chamber.
A hydraulic diaphragm type reciprocating pump 4 is schematically illustrated along with a schematic configuration of a hydraulic diaphragm type reciprocating pump 4 which is communicated through a pipe 3.

In this pump, the plunger 5 reciprocates as shown by the arrow, which causes pressure fluctuations in the drive chamber 2, and this changes the pump supply fluid in the pump chamber 7 on the other side via the diaphragm 6 as shown by the arrow. It is sent from inlet 8 to outlet 9. During such operation, the air present in the drive chamber 2 as a pressure chamber is caused by the hydraulic oil in the drive chamber 2 being discharged during the discharge stroke, that is, the stroke in which the plunger 5 moves forward into the chamber 2, and the suction stroke, that is, the stroke in which the plunger 5 moves backward. It is sequentially discharged to the outside using the pulsating flow that occurs over the course of the process. Further, of course, such a valve device 1 can also be provided in the pump chamber 7, but illustration and description thereof will be omitted.

A specific example of such a valve device 1 is shown in FIGS. 2a, 2b, and 2c, and its structure, operation, and problems will be explained. On the inlet 10 side of the device connected to the pipe 3 communicating with the drive chamber 2 in
A valve seat 11 is provided, and a first spherical valve body 12 constituting a check valve is disposed in a lower first valve chamber 1a corresponding to the first valve seat. This first
A second valve seat 1 is further provided on the upper part corresponding to the valve body 12.
3 is provided on the underside of an intermediate valve seat portion 14 which integrally projects inwardly at the intermediate portion of the device. A valve hole 15 is formed in the center of the valve seat portion 14 and extends in the fluid flow direction, and the second valve seat 13 is formed at the lower open end of this valve hole. Opposed to this, a third valve seat 16 is provided at the upper opening end of the valve hole 15, that is, above the valve seat portion 14. This valve seat 16 has a second valve seat formed above it.
A second valve constituting a check valve disposed in the valve chamber 1b of
It corresponds to the spherical valve body 17 of. Second valve chamber 1
The upper part of b communicates with an outlet 18 that communicates with the outside.

In such a configuration, the first and second valve bodies 12, 17 are normally connected to the corresponding first and third valve seats 1.
1 and 16 to prevent the flow from above to below in the opposite direction to the discharge direction, so-called reverse flow,
The pressure chamber is closed. As shown by arrow A in Fig. 2b, during the discharge stroke, as the fluid flows out as indicated by the arrow, the air in the fluid that has floated near the inlet 10 of the valve device first flows together with the fluid into the first valve. Until the body 12 is pushed up and separated from the first valve seat 11 and the valve body 12 comes into contact with the upper second valve seat 13, the second valve body 17 is further separated from the third valve seat 16. Let it separate and finally be released to the outside. Then, in the suction stroke, the first and second valve bodies 12, 17 return to contact the corresponding first and third valve seats 11, 16 as the fluid reverses. Therefore, backflow of fluid is suppressed as much as possible,
Also, air will not get inside. especially,
By providing the second valve body 17 having a check valve structure in addition to the first valve body 12, backflow can be prevented more reliably.

However, a problem with such a structure is that, as shown in FIG. 2b, in the discharge stroke, the first
During the period from immediately before to immediately after the valve body 12 closes the second valve seat 13, air flows into the first valve body 12.
, that is, in the valve hole 15 of the intermediate valve seat portion 14 .

That is, immediately before the first valve body 12 closes the second valve seat 13, the valve body 12 and the valve seat 13 close together.
Since the gap between the two is narrow, the flow velocity becomes extremely high, and therefore, according to Bernoulli's theorem, this gap becomes a negative pressure. Since the fluid itself that has passed through this gap is an incompressible fluid such as hydraulic oil, the valve hole 15
When it flows inside, the negative pressure is immediately eliminated because it is at atmospheric pressure. On the other hand, the air passing through the gap expands here due to the negative pressure, then enters the valve hole 15 and attempts to contract due to the atmospheric pressure, but due to its compressibility, it cannot change rapidly and the air There will be some time lag until the pressure is relieved. However, during this time lag, the first valve body 12 moves to the second valve seat 13.
When the third valve seat 16 is closed, the flow of fluid stops and the upper second valve body 17 falls onto the third valve seat 16, closing the valve seat. For this reason, depending on the above-mentioned operation timing, the air in the valve hole 15 may be trapped in a state where the negative pressure is not yet released.
As a result, both the valve bodies 12 and 17 are attracted to the corresponding valve seats as shown in Fig. 2c, and then the suction stroke shown by arrow B is started. In this case, the first valve body 12 could no longer move toward the first valve seat 11. Therefore, the air purge operation becomes completely impossible after that, requiring time and effort for maintenance, and the pump operation has to be stopped every time, which is a big problem.

Therefore, the purpose of this invention is to solve the problems of the air bleed valve device of the conventional structure described above, and to develop a new reciprocating pump that can always bleed air continuously and reliably and suppress backflow as much as possible. To provide an air bleed valve device.

In order to achieve the above purpose, in this invention,
An intermediate member is arranged between the first and second valve bodies, and when one valve body closes the corresponding valve seat, the other valve body is separated from the corresponding valve seat via the intermediate member. It was configured to do so.

Hereinafter, embodiments of this invention will be described with reference to the accompanying drawings, particularly FIGS. 3a to 3c and FIG. 4. Figures 3a, 3b and 3c include 2a, 3b and 3c.
2b and 2c, corresponding parts are given the same reference numerals, and detailed explanation thereof will be omitted.

In the air bleed valve device 1 of this invention shown in the embodiment, between the first valve body 12 in the first valve chamber 1a and the second valve body 17 in the upper second valve chamber 1b,
A pin-shaped intermediate member 20 having a constant length is disposed within the valve hole 15 of the intermediate valve seat portion 13 along the fluid flow direction. As can be seen in FIG. 4, this intermediate member 20 has a diameter smaller than the inner diameter of the valve hole 15, which has a circular cross section, and can freely move up and down within the valve hole. Of course, this cross-sectional shape may be of other shapes such as a rectangle. The length of the intermediate member 20 is slightly larger than the height or width of the intermediate valve seat portion 14, in other words, the length of the valve hole 15. However, its length does not necessarily have to be longer than the valve hole 15. At least one valve body, for example valve body 1
2 closes the second valve seat 13 as shown in FIG. 3b, the intermediate member 20 is pushed by this valve body and pushes up the upper second valve body 17 at the other end, that is, the upper end. It is sufficient that the length is sufficient to ensure that the third valve body 16 can be separated from the third valve body 16. Therefore, valve body 1
In some cases, the intermediate member 20 may be designed to be shorter than the valve hole 15 depending on the size relationship between the valve hole 15 and the valve hole 15.

Such an intermediate member 20 is a first member as shown in FIG. 3a.
When the valve body 12 is resting on the lower first valve seat 11, the lower end is lowered due to gravity to the state where it is in contact with the first valve body 12, but the upper end is in contact with the valve hole 1.
5 and its valve hole 15
The length of the upper end that has entered the interior, the outer diameter of the upper end (that is, the outer diameter of the intermediate member 20), and the valve hole 1
Due to the size of the gap between the first valve body 12 and the inner diameter of the first valve body 12, even if the intermediate member 20 moves downward to the maximum extent,
The structure is such that it does not fall out of contact with the valve chamber 1a and fall into the first valve chamber 1a. Note that although the gap between the intermediate member 20 and the valve hole 15 is shown in an exaggerated schematic diagram in the figure, in the actual structure, the gap is configured to be as narrow as possible while ensuring a sufficient flow cross-sectional area. , the valve hole 15 and the intermediate member 20 have a longer shape along the flow direction, and even in the downwardly protruding state (FIG. 3a), the intermediate member 20 does not deflect in the lateral direction of its protruding end. This prevents the valve from coming off the first valve body 12 and falling into the first valve chamber 1a. In this way, consideration is given to the height of the first valve chamber 1a, the diameter of the first valve body, the length of the intermediate member 20, and the inner diameter of the valve hole 15 in terms of size design.

As described above, since the intermediate member 20 is arranged between both the valve bodies 12 and 17, for example, in the discharge stroke indicated by the arrow A shown in FIG. 3b, the first valve body 12 comes into contact with the second valve seat 13. At this time, the second valve body 17 is forcibly pushed up and separated from the third valve seat 16 to reliably open the valve hole 15, so that the fluid containing air is reliably sent upward from the valve hole 15. In addition, in the suction process shown by arrow B in FIG. Since the member 20 is pushed by the second valve body 17, the lower first valve body 12 is forcibly removed from the corresponding second valve seat 13.

Therefore, the air bleed valve device of this invention reliably prevents the first valve body from being attracted to the valve seat due to the negative pressure action of the air existing in the valve hole of the intermediate valve seat, and prevents such a situation. This eliminates the hassle of maintenance caused by such occurrences, enables long-term continuous operation without stopping pump operation, and prevents backflow of fluid as much as possible due to the double prevention action of both valve bodies. Furthermore, the device of this invention has a simple structure and can be easily applied without significantly changing the existing conventional structure, so it can be manufactured at low cost and is highly economical.

In the above embodiment, a pin-shaped intermediate member separate from both valve bodies was used, but each end of the pin-shaped or rod-shaped intermediate member is connected to both valve bodies so that the upper and lower parts are integrated. A configuration in which it moves is also possible in terms of design.

Further, the shape of the valve body itself may be of course not only spherical but also other shapes such as a conical shape.

In addition, the intermediate valve seat part is not integrated with the device frame, but can be constructed separately or by a ring-shaped member separated vertically, and this invention is limited to the structure of the embodiment. isn't it.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a reciprocating pump equipped with an air bleed valve device, FIGS. 2a, 2b, and 2c are enlarged explanatory diagrams of a conventional air bleed valve device, and FIG. 3a,
3b and 3c are explanatory diagrams showing the air bleed valve device of this invention corresponding to FIGS. 2a to 2c, and FIG. 4 is a sectional view taken along line 4-4 in FIG. 3a. DESCRIPTION OF SYMBOLS 1... Air bleed valve device, 11... First valve seat, 12... First valve body, 13... Second valve seat,
14... Intermediate valve seat portion, 15... Valve hole, 16... Third valve seat, 17... Second valve body.

Claims (1)

[Claims for Utility Model Registration] (1) In order to release the air present in the pressure chamber by utilizing the pulsating flow that occurs in the pressure chamber of the fluid over the discharge stroke and suction stroke of the pump,
and a first and second valve body provided on both sides of the valve body.
an intermediate valve seat portion having a valve seat, a second valve body, and a third valve seat for the second valve body, wherein the second and third valve seats have valve holes. In the air bleed valve device for a reciprocating pump formed at each opening end of a valve hole, an intermediate member is disposed within the valve hole of the intermediate valve seat portion between the first and second valve bodies, and the When one valve body contacts the corresponding second or third valve seat to close the valve hole, the other valve body is brought into contact with the corresponding second or third valve seat via the intermediate member. An air bleed valve device characterized in that it is designed to be more disconnected. (2) The intermediate member according to claim 1, wherein the intermediate member is partially located within the valve hole even when the first valve body is in contact with the first valve seat. Air bleed valve device. (3) The air bleed valve device according to claim 1 or 2, wherein the length of the intermediate member is greater than the length of the valve hole.