JP3135227B2 - Plunger pump device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plunger pump device used for pumping a high-pressure fluid.

[0002]

2. Description of the Related Art Among pump devices used for pumping fluid, a plunger pump is used particularly for high-pressure fluid. A plunger pump reciprocates a round bar-shaped plunger in a cylinder, sucks fluid by changing the volume in the cylinder, and pumps fluid by discharging it. A valve is provided at each of the suction port and the discharge port of the fluid. Various sealing materials such as a packing and a gasket are used in the joints of the members forming the cylinder chamber and the fluid passages, including the sliding portion between the plunger and the cylinder, in order to maintain the airtightness.

For example, a plunger pump for high pressure is widely used in ground improvement works and the like. In this case, a liquid containing solid particles such as cement milk may be used as the high-pressure fluid. When cement milk containing such solid particles is pumped at high pressure using a plunger pump, large sliding heat is generated on the plunger sliding surface,
Since the solid particles in the cement milk enter the packing provided in the sliding portion, there is a problem that the packing is damaged in a short time.

[0004] As a means for solving these problems, there is a method of isolating a fluid to be fed and a sliding portion of a plunger from each other so as to prevent direct contact. For example, it is disclosed in JP-A-64-56975. FIG. 4 is a schematic cross-sectional view of one embodiment for explaining this method. The plunger pump device 110 includes a plunger 112
And a cylinder 116, and a sealing material such as a V packing 144 is provided on these sliding surfaces. The fluid to be pumped is sucked into the cylinder chamber as indicated by the arrow indicated by FIN, and is discharged as indicated by the arrow indicated by FOUT. A valve (not shown) is provided at each of the suction port and the discharge port. The feature of this method is that an elastic film 120 that partitions the valve side and the plunger side is provided in the cylinder chamber. The space on the plunger side surrounded by the elastic film 120 is filled with a pressure medium such as oil. The operation of the pump device will be described. When the plunger 112 moves to the position P0 in the suction process, the plunger 112
The elastic film contracts to the position of E0 by the volume change due to the receding. As a result, the valve-side space of the elastic film 120 becomes a negative pressure, a suction valve (not shown) opens, and fluid flows into the cylinder chamber (FIN). Next, when the plunger 112 moves to the position P1 in the discharge step, the elastic film expands to the position E1 by an amount corresponding to the volume change due to the advance of the plunger 112. As a result, the pressure in the valve-side space of the elastic film 120 becomes high, and a discharge valve (not shown) opens to discharge the fluid from the cylinder chamber (FOUT).

As described above, a diaphragm shown in FIG. 5 is well known as a mechanism for isolating a fluid and a plunger sliding portion in order to protect the plunger sliding portion from being affected by the fluid. I have. Diaphragm D in FIG.
Is provided as a partition for dividing the pump chamber into a piston P side and a valve side. The position of the illustrated diaphragm D is a discharge process, and in the suction process, the diaphragm D changes so as to bend in the opposite direction, that is, toward the piston P.

Providing a flexible partition in the cylinder chamber as in these conventional examples is somewhat effective in protecting the plunger and its peripheral members from the adverse effects of the pumping fluid.

[0007]

However, in order to achieve a high injection pressure in a high-pressure pump such as a plunger pump, it is necessary to move the plunger at a very high speed and increase the suction capacity of the pump per cycle. is there. When the plunger is moved at a high speed, a large amount of sliding heat is generated, so that the surrounding temperature is increased. Therefore, if the heat resistance of the peripheral members is insufficient, they deteriorate and break due to sliding heat. Non-metallic materials such as synthetic rubber are often used for the packing of the plunger sliding portion, other sealing materials, and the elastic film and the diaphragm that constitute the partition walls in the above-described cylinder chamber. Heat resistance temperature is much lower. The safe use temperature of general-purpose rubber materials used as sealing materials is up to about 90 ° C. In a high pressure plunger pump, sliding heat may exceed this heat resistant temperature, and as a result, these materials are damaged in a short time and must be replaced. Therefore, the working efficiency is reduced and the sliding surface of the plunger is also easily worn, so that the durability of the pump itself is also reduced.

Another problem is that the conventional elastic membrane or diaphragm constituting the partition in the cylinder chamber has a small deformation amount at the time of suction and discharge, so that the volume change of the fluid in the cylinder chamber cannot be increased. There is. This means that the suction capacity of the pump is low, which is disadvantageous in terms of the performance of the plunger pump which attempts to secure a high injection pressure.

As described above, an object of the present invention is to prevent deterioration of a seal member caused by sliding heat of a plunger in a plunger pump device, prolong the life of the seal member, and improve durability of the plunger pump device itself. That is.

It is another object of the present invention to provide a plunger pump device in which a plunger portion is isolated from a fluid to prevent an adverse effect from the fluid and to realize a good pump suction capacity.

[0011]

In order to achieve the above-mentioned object, in a plunger pump device according to the present invention, the plunger has a hollow portion formed in the longitudinal direction thereof and opened at a front end face thereof. A hollow plunger. The cylinder is composed of three cylinder spaces. The first cylinder chamber is a space in which the reciprocating motion of the hollow plunger is performed, and is filled with oil. The second cylinder chamber is a space located in front of the twelfth cylinder chamber and communicating with the first cylinder chamber.
It is surrounded by a cylindrical elastic body . The third cylinder chamber is a space surrounding the outside of the second cylinder chamber, and is a passage of a target fluid flowing from the suction valve to the discharge valve. Further, the first cylinder chamber is provided with an air vent for bleeding air mixed in the first cylinder chamber. A suction port connected to the suction valve is formed in the third cylinder chamber, and a discharge port connected to the discharge valve is formed. The suction port and the discharge port face each other across the center of the cylindrical elastic body. Is formed. in addition,
The cylindrical elastic body surrounding the second cylinder chamber is
The diameter of the central part is smaller than the diameter of both ends.
The diameter of the central part expands and contracts according to the internal pressure.
It is possible.

Further, a support member for supporting and fixing both ends of the cylindrical elastic body from inside is installed in the second cylinder chamber. The support has a disk-shaped pedestal portion for supporting and fixing the front end portion of the cylindrical elastic body, a main pillar portion extending axially rearward from the center of the pedestal portion, and extending rearward from a rear end of the main pillar portion. And a conical cone portion for supporting and fixing the rear end of the tubular elastic body. Further, the cone portion is provided with an oil passage hole for communicating the first cylinder chamber with the second cylinder chamber. Further, a radiator plate is provided in contact with the front surface of the pedestal portion of the support, and radiates heat inside the plunger pump device to the outside.

[0013]

With the hollow plunger, the sliding heat is transmitted to the oil in the hollow portion without accumulating in the plunger, and the heat is transferred to the second oil by the reciprocating movement of the plunger in the first cylinder chamber. It is carried to the cylinder chamber. The heat is conducted to the heat radiating plate via the support provided in the second cylinder chamber, and is released to the outside. Thereby, the sliding heat is discharged to the outside, and it is possible to prevent the inside of the pump device from being overheated. Further, the cylindrical elastic body that deforms in response to a change in the volume of the cylinder chamber due to the reciprocating motion of the plunger can obtain a large deformation amount due to its shape characteristics, and can secure a high suction capacity.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings. In this specification, the valve side as viewed from the plunger is referred to as a front side, and the opposite side is referred to as a rear side.

FIG. 1 shows a schematic sectional view of a main part of a plunger pump device according to the present invention. The plunger pump device 10 includes a cylinder portion 16a, 16b forming a round rod-shaped plunger 12 and a substantially cylindrical cylinder chamber space 17a.
Is provided. Similar to the conventional plunger pump, the cylinder portion 16a has sealing materials such as a U packing 42 and a V packing 44 disposed between the cylinder portion 16a and the outer peripheral surface of the plunger 12. A portion between the inner surface of the cylinder portion 16a and the sealing material and the outer peripheral surface of the plunger 12 serves as a sliding surface when the plunger 12 reciprocates. The position P0 of the illustrated plunger 12 is
It shows the most retracted position in the suction process. The position P1 of the plunger 12 indicated by the broken line indicates the most advanced position in the discharge process. In the present invention, the plunger 1
One of the features is that 2 has a cylindrical structure having a hollow portion 14.

A cylinder chamber 1 is provided on the wall of the cylinder portion 16b.
An oil inlet 32 for supplying oil into the cylinder chamber 7a, an oil outlet 36 for discharging oil from the cylinder chamber 17a, and an air vent 34 for removing air mixed into the cylinder chamber 17a are perpendicular to the axis. It is provided in various directions. The oil filled in the cylinder chamber has a function as a pressure medium.

In the present invention, cylinder chambers 17b and 17c are further provided axially forward of the cylinder chamber 17a. The cylinder chamber 17b is a space surrounded by a rubber cylinder 20, which is a cylindrical elastic body having a constriction at the center, and the rubber cylinder 20 is supported and fixed by a support 22 installed inside the rubber cylinder 20. The rubber cylinder 20
It is formed from an elastic material such as rubber. The cylinder chamber 17a and the cylinder chamber 17b communicate with each other through an oil passage hole 22e formed in the conical rear wall of the support 22. That is, the cylinder chamber 17a and the cylinder chamber 17b
Is always filled with oil.

FIG. 2 is a schematic perspective view showing the appearance of the rubber cylinder 20. The rubber cylinder has a cylindrical shape formed of an elastic material such as rubber. The body 20a has a smaller diameter at the center than at both ends and is constricted. During operation of the pump, the diameter of the central portion of the rubber cylinder 20 changes in shape such that the expansion and contraction are repeated periodically. The details will be described in conjunction with the operation described below.

FIG. 3A is a perspective view showing the appearance of a support 22 for fixing and supporting the rubber cylinder 20 from the inside thereof, and FIG. 3B is a view of the support 22 viewed from the rear end side. It is a side view. The support 22 includes a main pillar portion 22a, a pedestal portion 22d on the front end side, and a cone portion 22b on the rear end side. The main pillar portion 22a connects the center of the pedestal portion 22d made of a circular plate and the vertex of the conical cone portion 22b. Four oil passage holes 22 e penetrate substantially parallel to the axis of the support 22 on the wall forming the conical surface of the cone portion 22 b of the support 22. As shown in FIG. 3B, these oil passage holes 22e are
They are arranged symmetrically about two axes. Reference numeral 22f is
The vertex of the cone of the cone portion 22b is shown. By forming the cone portion 22b in such a conical shape, the cylinder chamber 17
When the oil of a is pushed forward by the plunger 12, the oil flows along the conical surface and the oil passage hole 22
e so as to smoothly flow into the cylinder chamber 17b.

As shown in FIG. 1, the support 22 is installed so that its axis coincides with the cylinder chamber 17b, that is, the axis of the rubber cylinder 20. The support 22 also serves to fix both ends of the rubber cylinder 20 to the cylinder 16c. Specifically, the pedestal 2 of the support 22
The front end 20c of the rubber cylinder 20 is sandwiched between the periphery of 2d and the cylinder 16c, and the rear end 20b of the rubber cylinder 20 is located between the cone rear end 22c of the support 22 and the cylinder 16c. Sandwich.

On the other hand, the cylinder chamber 17c is a space surrounding the outside of the rubber cylinder 20.
And 17b are separated by a rubber cylinder 20. The cylinder chamber 17c is also a passage for the fluid pumped by the pump device 10. Fluid (indicated by arrow FIN) sucked from a suction valve (not shown) passes through the cylinder chamber 17c and is delivered to a discharge valve (not shown) (indicated by arrow FOUT).

Further, in FIG. 1, a heat radiating plate 26 is provided so as to be in contact with the cylinder portion 16c and the front end of the support 22. The radiator plate 26 plays a role of releasing heat inside the plunger pump device to the outside.

Next, the operation of the plunger pump device according to the present invention having the above configuration will be described. In FIG. 1, a position P0 of the plunger 12 indicated by a solid line is a position when the plunger 12 is retracted most in the suction process. During the retreating movement of the plunger 12, the volume of the cylinder chamber 17a expands to a negative pressure, so that the oil passage hole 22e
Then, the oil moves from the cylinder chamber 17b to the cylinder chamber 17a. As a result, the plunger chamber 17b becomes a negative pressure, and the body of the rubber cylinder 20 is deformed so as to be constricted (indicated by a solid line RS0). As a result, the volume of the cylinder chamber 17c expands to a negative pressure, and the pumping fluid flows from the suction valve into the cylinder chamber 17c (arrow FIN).

Thereafter, in the discharge step, the plunger 12
Moves forward to a position P1 shown by a broken line in FIG. When the plunger 12 moves forward, the volume of the cylinder chamber 17a decreases, and the cylinder chamber 1a passes through the oil passage hole 22e.
Oil is pushed out from 7a into the cylinder chamber 17b.
As a result, the internal pressure of the plunger chamber 17b increases, and the body of the rubber cylinder 20 deforms so as to expand (indicated by a broken line RS1). As a result, the volume of the cylinder chamber 17c is reduced to a high pressure, and the pumping fluid is sent from the cylinder chamber 17c to the discharge valve (arrow FOUT).

The rubber cylinder 20 not only separates the oil serving as the pressure medium from the target pumping fluid, but also has a characteristic cylindrical shape, which allows a large volume change of the cylinder chamber as compared with the conventional elastic isolation membrane or diaphragm. Can be secured. As a result, the suction capacity of the plunger pump device is greatly increased.

The rubber cylinder 20 of the present invention
Is located forward of the most distal position of the plunger 12, and is far from the plunger 12, so that it is hardly affected by the sliding heat. Further, the cylinder chamber 17a in which the plunger 12 reciprocates and the cylinder chamber 17b surrounded by the rubber cylinder 20 are separated by a cone portion of the support 22, so that the rubber cylinder 20
The effect of direct heat from the cylinder chamber 17a can be avoided. The support 22 is desirably formed of a material having good thermal conductivity, and efficiently dissipates the heat of the oil to the heat sink 2.
6 has the function of transmitting to In this way, the rubber cylinder 20 can avoid overheating of the elastic material above the allowable temperature limit.

Furthermore, the plunger 1 according to the present invention
2 is provided with a hollow portion 14 along its axis, and the hollow portion 14 is also filled with oil. The sliding heat generated between the conventional plunger and the cylinder portion is accumulated in the plunger or the cylinder and increases the temperature of these constituent members and oil because there is no means for efficiently releasing the surroundings, and as a result, The packing and the diaphragm were to be overheated and damaged. On the other hand, in the present invention, by using a hollow plunger, heat accumulated in the plunger 12 easily moves to the oil filled in the hollow portion 14. In addition, the oil in the hollow portion 14 and the oil filled in the cylinder chambers 17a and 17b macroscopically move between the respective cylinder chambers with the movement of the plunger 12, so that the support from the plunger 12 through the oil The transfer of heat to 22 and further to radiator plate 26 is further promoted.

[0028]

According to the plunger pump device of the present invention,
The components of the hollow plunger, the oil, the support, and the radiator plate function effectively with each other, so that the sliding heat can be removed and released to the outside. Thus, overheating inside the pump device is prevented, and the pump device can be operated at a temperature equal to or lower than the heat-resistant temperature of the sealing material. Specifically,
In the embodiment, the temperature rise of the oil is set to the outside air temperature + 40 ° C.
It could be controlled within. Since the heat resistance temperature of a general-purpose sealing material is at least about 90 ° C., any sealing material can be used at a temperature lower than the heat resistance temperature.

As described above, it is possible to secure the use of the non-metal components such as the sealing material and the rubber cylinder characteristic of the present invention at a temperature lower than the heat-resistant temperature, so that it is possible to avoid the breakage of these components in a short time. . As a result, wear of the plunger sliding surface is reduced, and the durability of the plunger pump device itself is also improved. In addition, the frequency of replacing damaged parts is significantly reduced, so that work efficiency is improved.

Further, since a cylindrical rubber cylinder is used as an elastic body corresponding to a conventional diaphragm or the like for transmitting a change in volume in the cylinder chamber due to the reciprocating movement of the plunger, a large amount of deformation can be obtained as compared with the conventional case. . As a result, a pump device having a high suction capacity is obtained. Of course, since the rubber cylinder also plays a role of isolating the target fluid and the plunger sliding portion, even in the case of the target fluid containing solid particles such as cement milk, solid particles do not enter the plunger sliding portion. .

[Brief description of the drawings]

FIG. 1 shows a schematic sectional view of a main part of a plunger pump device according to the present invention.

FIG. 2 is a schematic perspective view showing the appearance of a rubber cylinder used in the plunger pump device according to the present invention.

FIG. 3 is a schematic perspective view showing the appearance of a support used in the plunger pump device according to the present invention.

FIG. 4 is a schematic sectional view of a conventional plunger pump device.

FIG. 5 is a schematic sectional view of a conventional diaphragm pump device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Plunger pump apparatus 12 Plunger 14 Plunger hollow part 16 Cylinder part 20 Rubber cylinder 20a Rubber cylinder trunk part 20b Rubber cylinder rear end part 20c Rubber cylinder front end part 22 Support body 22a Main column part 22b Cone part 22c Cone rear part 22d Cone Base 22e Oil passage hole 22f Cone apex 26 Heat sink 32 Oil inlet 34 Air vent 36 Oil outlet 42 U packing 44 V packing P0 Plunger position at suction P1 Plunger position at delivery RS0 Rubber cylinder shape at suction RS1 Rubber cylinder shape at delivery F, FIN, FOUT Fluid flow 110 Plunger pump 112 Plunger 116 Cylinder E0 Elastic membrane shape at suction E1 Elastic membrane shape at delivery

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F04B 9/111 F04B 43/067

Claims (3)

(57) [Claims] 1. A plunger pump device which reciprocates a plunger in a cylinder to send out fluid sucked in from a suction valve as a high-pressure fluid from a discharge valve, wherein the plunger is bored along a longitudinal axis thereof. And a hollow plunger having a hollow portion opened at the front end face thereof, and wherein the cylinder is a space in which the reciprocating motion of the plunger is performed, and a first cylinder chamber filled with oil; A second cylinder chamber, which is located in front of the first cylinder chamber and communicates with the first cylinder chamber and is surrounded by a cylindrical elastic body; and a space outside the second cylinder chamber. A third cylinder chamber that is a surrounding space and is a passage of a fluid that flows from the suction valve to the discharge valve; Air vent port for venting air mixed in the cylinder chamber of the first is formed, the tubular elastic body surrounding said second cylinder chamber, its
The diameter of the central part is smaller than the diameter of both ends.
The diameter of the central part expands and contracts according to the internal pressure.
A suction port connected to the suction valve is formed in the third cylinder chamber, and a discharge port connected to the discharge valve is formed in the third cylinder chamber. The suction port and the discharge port are located at the center of the cylindrical elastic body. A plunger pump device formed at a position facing each other across a portion. 2. A support which is installed inside the second cylinder chamber and supports and fixes both ends of the tubular elastic body from the inside, wherein the support is provided at a front end of the tubular elastic body. A disk-shaped pedestal portion for fixed support, a main column extending rearward on the axis from the center of the pedestal, and a rear end supporting and fixing the cylindrical elastic body extending rearward from the rear end of the main column. 2. The plunger according to claim 1, wherein the plunger has a conical cone portion having an oil passage hole communicating the first cylinder chamber and the second cylinder chamber. 3. Pump device. 3. The plunger pump device according to claim 2, further comprising a radiator plate provided in contact with a front surface of the pedestal portion of the support, and radiating heat in the plunger pump device to the outside. .