JPH0645664Y2 - Reciprocating pump - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reciprocating pump, and in particular, it has a large diameter portion and a small diameter portion having different diameters, and a suction port and a discharge port are provided in respective pump chambers to provide a low pressure large discharge amount and a high pressure. The present invention relates to a reciprocating pump that can be used for a small discharge amount.

[0002]

2. Description of the Related Art A conventional reciprocating pump, as shown in FIG. 3, is a plunger that can generate one kind of discharge pressure and discharge amount on a connecting rod 3 which is supported by a crankcase 1 via a crankshaft 2. 4 are pin-connected, and the plunger 4 is fixed to the crankcase 1 and a seal is provided in a cylinder 9 in which an intake port 6 having an intake valve 5 and a discharge port 8 having a discharge valve 7 are formed. A V-packing 10 is slidably slidable in a water-tight state via a V-packing 10 which is a portion of the cylinder, and the V-packing 10 is slidably connected to the base end of the cylinder 9 in the sliding direction of the plunger 4 by a back-up ring 11. It is compressed.

[0003]

However, as described above, the conventional reciprocating pump has the pump chamber 1 of the plunger 4 as described above.
Since the pressure of 2 is directly supported by the V-packing 10, the V-packing 10 cannot support this pressure at a high pressure, and the V-packing 10 may protrude between the back-up ring 11 and the plunger 4 to prevent this. In order to withstand a high pressure, it is necessary to reduce the gap between the back-up ring 11 and the plunger 4, which requires machining accuracy of the back-up ring 11 and the like and peripheral assembly accuracy, resulting in cost up. .

[0004]

[Means for Solving the Problems] The present invention has been made in view of the above-mentioned circumstances, and reciprocates a plunger (21) having a large diameter portion (22) and a small diameter portion (23) having different diameter portions. To move
The pump chambers (29, 30) of the plunger (21) are separated by the seal portion (28) of the small diameter portion (23), and these pump chambers (29, 30) are connected to the suction valve (31, 32). ) Through the suction port (33,
34) In the reciprocating pump communicating with
(29,30) through the discharge valve (35,36)
8) and open / close valves in these pressure regulation chambers (37, 38) respectively.
(46,47) discharge port (48,49) and pressure regulating valve (44,45) are formed respectively, and the pressure regulating chamber (37,38) is communicated via the on-off valve (50), and the small diameter Part (23) Pump chamber (30) Suction port (3
4) directly communicates with the pump chamber (29) of the large diameter portion (22),
A reciprocating pump characterized in that the suction port (33) of the pump chamber (29) of the large diameter portion (22) is directly communicated with the seal portion (27) of the large diameter portion (22) is proposed. To do.

[0005]

In the reciprocating pump having the above structure of the present invention, the pressure generated by the pumping action of each of the large diameter portion and the small diameter portion is provided on the rear surface of the seal portion which separates the pump chambers of both diameter portions of the plunger. By acting as a back pressure, it is possible to obtain a reciprocating pump capable of improving the pressure resistance of the seal portion and capable of producing two kinds of discharge states of a high pressure small flow rate and a low pressure large flow rate. Is.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to the accompanying drawings. 1 and 2 are cross-sectional views of different embodiments of the reciprocating pump of the present invention. First, the one shown in FIG. 1 will be described. In the figure, 21 is a large-diameter portion 22 and a plunger having a small-diameter portion 23 integrally formed at its tip, and the plunger 21 is provided with a large-diameter portion 25 of a manifold 24 and a small-diameter portion 26 formed at its tip. The large-diameter portion 22 and the small-diameter portion 23 of the plunger 21, respectively, are slidably installed in a water-tight state via V-packings 27 and 28 which are seal portions.
The pump chambers 29 and 30 formed by the large diameter portion 22 and the small diameter portion 23 of the plunger 21 are separated from each other by the V packing 28 of the small diameter portion 23.

The pump chambers 29 and 30 formed by the large-diameter portion 22 and the small-diameter portion 23 of the plunger 21 are suction ports 33 formed in the manifold 24 via suction valves 31 and 32.
And 34, respectively, and via the discharge valves 35 and 36, respectively, a pair of pressure adjusting chambers 37 and 38 also formed in the manifold 24. The suction port 33 is communicated with a passage 39 which is capable of communicating with a liquid source (not shown), and the passage 39 is provided with the plunger 2
It is communicated with a chamber 41 formed between the V packing 27 of the first large-diameter portion 22 and a V packing 40 which is disposed at a constant interval behind the V packing 27. Further, pressure regulating valves 44 and 45 having spill ports 42 and 43 are provided in both pressure regulating chambers 37 and 38, respectively.
And discharge ports 48 and 49 having open / close valves 46 and 47, respectively, are provided, and both pressure regulating chambers 37 and 38 are communicated with each other via an open / close valve 50.

The suction port 34 of the pump chamber 30 of the small diameter portion 23 of the plunger 21 is directly communicated with the pump chamber 29 of the large diameter portion 22 of the plunger 21 through the passage 60, and the suction port 34 is the suction port. A passage 39 communicates with the chamber 41 via a valve 31. A reciprocating pump according to another embodiment of the present invention shown in FIG. 2 is one in which the position of the suction valve 31 shown in FIG. 1 is only moved to the side in the sliding direction of the plunger 21 of the other suction valve 32. The other configuration of the embodiment of FIG. 2 is the same as that of FIG. 1, and therefore illustration and description thereof will be omitted.

As described above, according to the reciprocating pump of the present invention, in order to use the reciprocating pump in a state of high pressure and small discharge amount, for example, in FIG.
cm ² and the pressure regulating valve 45 at a desired pressure of 1500 kgf / cm ²
By adjusting the respective pressures, the on-off valve 50 is closed, and the on-off valve 47 is opened, a higher pressure than the discharge port 49 (for example, 15
A small discharge amount of fluid can be obtained at 00 kgf / cm ² ). At this time, high pressure (for example, 1500 kgf / c
m ² ) on the back surface of the V packing 28, the pressure of the low pressure pumping portion 29 (for example, 500 kg
f / cm ² ) as a back pressure, the actual pressure of the V packing 28 at this time is 1000 kgf / c.
m ² (1500 kgf / cm ² -500 kgf / cm ² )
Since the burden of V packing is reduced as compared with the case where no back pressure is applied, the pressure resistance can be improved. Furthermore, the suction valve 3 that defines the high-pressure pump chamber 30
2, the pressure in the pump chamber 29 acts as a back pressure,
The stress gradient in the intake valve 32 is relaxed, thus improving durability.

On the other hand, in order to use in a state of low pressure and large discharge amount, in FIG. 1, either one of the pressure regulating valves 44 or 45 is regulated to a desired low pressure, and the other pressure regulating valve 45 or 44 is regulated from the low pressure. Is adjusted to a considerably high pressure, the on-off valve 50 is opened, and one of the on-off valves 46 and 47 is opened and the discharge port 48
Alternatively, it is possible to discharge a fluid having a low pressure and a large discharge amount than one of 49. Further, for example, if the pressure regulating valve 45 is adjusted to a high pressure and the pressure regulating valve 44 is adjusted to a low pressure and only the opening / closing valve 47 on the high pressure side is set to open, the opening / closing of the opening / closing valve 50 causes a rapid low pressure large discharge. It is possible to select the discharge state of the discharge amount and the high pressure small discharge amount by switching, and it is particularly effective for the cleaning device which is used by frequently switching these two states.

[0011]

Since the reciprocating pump according to the present invention is as described above, it has the following effects. (1) When used at a high pressure and a small discharge amount, the pressure of the low-pressure side pump chamber 29 acts as a back pressure on the back surface of the V packing (sealing portion) 28 that supports the high pressure. The load is reduced and the working fluid lubricates the V packing 28. Therefore, the pressure resistance of the V packing 28 can be further improved, and the water tightness can be improved. (2) Further, since the pressure load on the V packing 28 is reduced, it is possible to reduce the processing accuracy of the V packing holding portion and the peripheral assembly accuracy, which can contribute to the reduction of the processing time and the assembly time. (3) Adjusting the pressure of each of the pressure regulating valves 44 and 45,
By opening / closing each of the on-off valves 46, 47, and 50, the fluid can be discharged in two kinds of discharge states of high pressure and low pressure.

(4) In the above description, two different diameter portions 2 are used.
Although the two-stage plunger 21 having 2, 23 is used, a higher-pressure fluid can be discharged by using the multi-stage plunger having a larger number of different diameter portions. (5) Since the fluid leaking from the high pressure pump chamber 30 through the gap of the V packing 28 is absorbed by the lower pressure pump chamber 29, it is possible to prevent the fluid from leaking to the outside. Low pressure pump chamber 29, packing 40 and chamber 41
The relationship with is similar. (6) Since the suction valve 32 defining the high-pressure pump chamber 30 receives the pressure of the low-pressure pump chamber 29 as a back pressure, the stress gradient generated in the suction valve 32 is relaxed and the durability is improved.

[Brief description of drawings]

FIG. 1 is a sectional view of a reciprocating pump of the present invention.

FIG. 2 is a sectional view showing a main part of another embodiment of the reciprocating pump of the present invention.

FIG. 3 is a sectional view of a conventional example.

[Explanation of symbols]

 21 Plunger 22 Large diameter part 23 Small diameter part 27,28 V packing (sealing part) 29,30 Pump chamber 31,32 Suction valve 33,34 Suction port 35,36 Discharge valve 37,38 Pressure regulation chamber 44,45 Adjustment Pressure valve 46,47,50 Open / close valve 48,49 Discharge port

Claims (1)

[Scope of utility model registration request] 1. A plunger (21) having a large diameter portion (22) and a small diameter portion (23) having different diameter portions is reciprocated to move the respective pump chambers (29, 30) of the plunger (21). The small diameter part (23)
In the reciprocating pump, which is isolated by the seal part (28) of the above, and these pump chambers (29, 30) communicate with the suction ports (33, 34) via the suction valves (31, 32), respectively. The chambers (29, 30) communicate with the pressure regulating chambers (37, 38) via the discharge valves (35, 36),
In these pressure regulating chambers (37, 38) are formed discharge ports (48, 49) and pressure regulating valves (44, 45) each having an on-off valve (46, 47),
The pressure regulating chambers (37, 38) are communicated with each other via the opening / closing valve (50), and the suction port (34) of the pump chamber (30) of the small diameter portion (23) is connected to the pump of the large diameter portion (22). This large diameter part (22) is directly connected to the chamber (29).
The suction port (33) of the pump chamber (29) of the
A reciprocating pump characterized in that it directly communicates with the base part (27).