JPH0437270Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention is a pump suitable for irrigation pumps and pesticide spraying, which is used for agriculture, and is also suitable for high pressure pumps for agricultural machinery, tractors, combine harvesters, tailors, trucks, etc. This pump is suitable for cleaning, and can wash away chemicals, fertilizers, etc. from the machine body, thereby contributing to improving the durability of the above-mentioned mechanical equipment. Further, back pressure can be applied to the high-pressure packing in an adjustable manner when high-pressure liquid is discharged, and the pressure gradient between the front and rear surfaces of the packing can be reduced, thereby making it possible to extend its life.

[Prior Art] In a conventional reciprocating pump, a piston means capable of generating one type of discharge pressure and discharge amount is connected by a pin to a connecting rod that is supported via a crankshaft in a crankcase. It is slidably installed in a water-tight manner so that it can reciprocate within a cylinder body that is fixed to the cylinder body.

[Problem that the invention aims to solve] Therefore, conventional reciprocating pumps have a limited specification range, such as an upper limit of pressure.
Within this range, the water absorption amount is determined and used within the allowable range of the required power and flow rate limit. Therefore, when exceeding this range by a wide range, it was necessary to use two pumps independently, or to connect them in parallel using a crank or the like. However, this method requires two reciprocating pumps, requires a large installation space, requires complicated piping, and is expensive. Furthermore, in conventional reciprocating pumps, the higher the discharge pressure, the greater the stress gradient that occurs inside the seal gasket that slides on the periphery of the plunger that reciprocates within the cylinder and defines the pump chamber, ensuring sufficient durability. Otherwise, the sealing performance could not be maintained.

[Means for solving the problem] This invention was devised in view of the above-mentioned circumstances, and includes a connecting rod 5 that is pivotally supported on the crankcase 1 via the crankshaft 4, and a pin at the tip of the connecting rod 5. It is a reciprocating pump comprising a piston means 11 connected to each other and capable of reciprocally sliding within a cylinder body 8, the cylinder body 8 comprising a cylinder large diameter portion 6 and a cylinder small diameter portion 7. The cylinder large diameter part 6 and the cylinder small diameter part 7 are provided with packings 13 and 14, respectively, of a piston large diameter part 9 and a piston small diameter part 10 that constitute the piston means 11.
The piston large diameter part 9 and the piston small diameter part 1 are slidably installed in a water-tight manner through the cylinder large diameter part 6.
A large-diameter chamber 18 is defined by the large-diameter chamber 18, and the large-diameter chamber 18 includes a large-diameter suction port 20 having a suction valve 19 and a large-diameter discharge port 22 having a discharge valve 21.
A small-diameter chamber 23 defined by the piston small-diameter section 10 is formed on the tip side of the cylinder small-diameter section 7, and a small-diameter discharge port 25 having a discharge valve 24 is provided in the small-diameter chamber 23. 10 is in sliding contact with the packing 14 via a cylindrical sleeve 10a which is loosely fitted to the outer side of the sleeve 10a so as to be movable in the axial direction with a space maintained therebetween. and connecting the blocking member 10b in which the suction port 26 is formed,
A suction valve 27 is formed at the proximal end of the sleeve 10a, and the suction valve 27 can open and close the suction port 26 and the large diameter chamber 18 in communication with each other through the inside of the sleeve 10a, and a means 29 for opening and closing the small diameter discharge port 25 is provided. communicates with the large-diameter discharge port 22 through a communication passage 28, and
The present invention proposes a reciprocating pump which communicates with the outside through a branch passage 30 and is characterized in that a pressure regulating means is provided between the discharge side of the large-diameter discharge port 22 and the opening/closing means 29. be.

[Function] That is, in the reciprocating pump of this invention having the above structure, the piston means 11, which is formed integrally with the small diameter piston portion 10 and the large diameter piston portion 9, advances and retreats in the small diameter portion chamber 23 and the large diameter portion chamber 18, respectively, and the discharge valve 24, discharge valve 21, communication path 28, opening/closing means 2
9 to merge at a branch path 30 and connect to the communication path 28.
A pressure regulating means 31 is interposed therein.

Therefore, when the pressure is low and the flow rate is large, the opening/closing means 29 is opened, and the piston small diameter section 10 and the piston large diameter section 9 are used to send liquid.The pressure regulating means 31 is used to regulate the pressure, and when the pressure is high and the flow rate is small, the opening/closing means 29 is opened. The means 29 is closed, and discharge is performed at a pressure set by a pressure regulating means (not shown) disposed in a pipe communicating with the branch passage 30.

The above-mentioned low-pressure, large-flow discharge and high-pressure, small-flow discharge can be selected by operating the opening/closing means, and when high-pressure, small-flow discharge is performed, the back pressure of the packing 14 is adjusted according to the operating pressure by adjusting the pressure regulating means 31. It is configurable.

[Example] An example of this invention will be described below based on the accompanying drawings.

The attached drawing is a cross-sectional view showing a reciprocating pump according to this invention. In the drawing, 1 is a crankcase that has legs 2 at the bottom and can be installed on a floor or the like 3.
A connecting rod 5 is pivotally supported via a crankshaft 4.
A cylinder body 8 is fixed to the distal end of the crankcase 1, which is integrally formed with a cylinder large diameter section 6 at the base end and a cylinder small diameter section 7 at the distal end.

A piston large diameter portion 9 is provided at the tip of the connecting rod 5.
A piston means 11 comprising a piston small diameter portion 10 integrally formed at the tip thereof is attached to a pin 1.
Connected by 2. The piston large diameter portion 9 of the piston means 11 has a larger outer diameter than the piston small diameter portion 10, and the piston large diameter portion 9 is disposed within the cylinder large diameter portion 6, and the piston small diameter portion 10 is provided with a sleeve 10a to be described later. They are loosely fitted and slidably reciprocated in the cylinder small diameter portion 7 via V packings 13 and 14 in a water-tight manner. The packings 13 and 14 are fixed in a compressed state to the cylinder large diameter section 6 or the cylinder small diameter section 7 by a gland screw 15 or a compression spring 16, respectively. Further, an oil seal 17 is interposed between the cylinder body 8 and the crankcase 1 to prevent oil in the crankcase 1 from entering the cylinder body 8.

The cylinder large diameter portion 6 includes a piston large diameter portion 9.
A large-diameter chamber 18 is defined by the piston small-diameter section 10 and a suction valve 1 is provided in the large-diameter chamber 18.
While forming a large diameter suction port 20 with 9,
A large-diameter discharge port 22 provided with a discharge valve 21 is formed.

A small diameter chamber 23 defined by the piston small diameter section 10 is provided on the tip side of the cylinder small diameter section 10.
form. A small-diameter discharge port 25 having a discharge valve 24 is formed in the small-diameter chamber 23 .

Further, the piston small diameter portion 10 is configured to be in sliding contact with the packing 14 via the aforementioned cylindrical sleeve 10a which is loosely fitted to the outside thereof so as to be movable in the axial direction with a space maintained therebetween, and the tip of the piston small diameter portion 10 A disk-shaped blocking member 10b that prevents the sleeve 10a from coming off is connected by screws, and a small-diameter suction port 26 is formed in the blocking member 10b to communicate the inside of the cylinder of the sleeve 10a and the small-diameter chamber 23. Further, a suction valve 27 is formed at the proximal end of the sleeve 10a to allow the small diameter suction port 26 and the large diameter chamber 18 to communicate with each other in an openable and closable manner through the inside of the sleeve 10a.

The large diameter outlet 22 and the small diameter outlet 25 are
They are communicated with each other by a communication passage 28 formed on the side of the cylinder small diameter portion 7, and a switching cock 29 which is an opening/closing means for closing the communication passage 28 is provided inside the communication passage 28. The small diameter discharge port 25 communicates with the outside through a branch path 30 branched from the communication path 28. Further, a pressure regulating valve 31 serving as a pressure regulating means is installed in the communication passage 28 between the large diameter discharge port 22 and the switching cock 29. In addition, pressure regulating valve 3
32 shown in 1 is a spillway.

Since the reciprocating pump according to this invention is as described above, the fluid is pumped into the large diameter chamber 18 from the large diameter suction port 20 by the reciprocating movement of the piston large diameter section 9 and the piston small diameter section 10 due to the rotation of the crankshaft 4. and discharged into the communication passage 28 from the large-diameter discharge port 22. The discharge amount at that time is defined as Q1.

Further, when the piston small diameter portion 10 moves to the right in the figure during the reciprocating motion of the piston means 11, the sleeve 10a moves to the left relative to the piston small diameter portion 10 due to the frictional force between the sleeve 10a and the packing 14. When the suction valve 27 at the proximal end of the sleeve 10a is opened, fluid flows from the large diameter chamber 18 into the small diameter chamber 23 through the small diameter suction port 26, and when the piston small diameter section 10 moves to the left. In this case, the sleeve 10a moves relatively to the right in the opposite direction, the suction valve 27 closes, and the fluid in the small diameter chamber 23 is discharged to the outside through the small diameter discharge port 25 and the branch passage 30. do. The discharge amount at this time is defined as Q2.

Now, a pipe line communicating with the branch line 30 is provided, a pressure regulating means (not shown) is disposed in a part of the pipe line, and the regulating pressure of this pressure regulating means is set to P2 (>P1). Here, P1 is the set pressure of the pressure regulating valve 31.

By operating the handle 29a of the switching pot 29 to open or close the communication passage 28, when the switching pot 29 is open, the discharge pressure becomes P.
1. The discharge amount is approximately Q1 + Q2, and the switching rate is 2.
When 9 is closed, two types of fluid can be discharged: the discharge pressure is P2, and the discharge amount is about Q2.

In the above example, the pressure regulating valve 31 was arranged in a part of the pipe line communicating with the branch line 30, but it is integrated with the pump,
A similar effect can be obtained by disposing a pressure regulating valve on the secondary side (discharge side) of the small diameter piston near the branch passage. Furthermore, when the switching pot 29 is closed, the pressure P1 set by the pressure regulating valve 31 acts on the packing 14 as back pressure. The pressure gradient before and after 14 can be made small,
Further, the contact between the sleeve 10a and the packing 14 is made closer, and the packing 14 is brought into closer contact with the sleeve 10a.
The durability and sealing performance of No. 4 can be improved, and it can contribute to stable high-pressure fluid discharge.

[Effects of the invention] The reciprocating pump according to this invention has the following effects.

(1) Low pressure and large capacity with only one reciprocating pump (P1,
Q1+Q2) and high voltage and small capacity P2 and Q2 can be used more widely.

(2) Since the pressure P1 of the large diameter section chamber 18 acts as back pressure on the packing 14 of the piston small diameter section 10, the compressive force by the spring 16 can be increased, and therefore the packing 14 and the sleeve The contact pressure with the packing 10a is increased, contributing to leakage prevention, and the pressure gradient between the high pressure side and the low pressure side of the packing 14 can be reduced, and the durability of the packing 14 can be further improved.

(3) The pressure in the large diameter chamber 18 can be adjusted appropriately by the pressure regulating means 31, and acts on the outer peripheral edge of the sleeve 10a, suppressing the deformation of the sleeve from expanding during liquid feeding. It is possible to use a sleeve with a thin wall, and therefore the mass of the sleeve, which reciprocates between the blocking member 10b and the suction valve 27 and repeatedly collides with it, can be reduced, thereby reducing noise caused by collisions. At the same time, deformation of the water intake valve can be reduced, contributing to improved durability of the pump.

(4) Since the packing 14 is lubricated by pumped liquid from both high and low pressure sides, durability is improved.

[Brief explanation of the drawing]

The accompanying drawing is a sectional view showing a reciprocating pump according to this invention. In the figure, 1... crankcase, 4...
...Crankshaft, 5...Connecting rod, 8...Cylinder body, 6...Cylinder large diameter part, 7...Cylinder small diameter part, 9...Piston large diameter part, 10...Piston small diameter part, 11...Piston Means, 13, 14... Packing, 18... Large diameter chamber, 19... Suction valve,
20...Large diameter suction port, 21...Discharge valve, 22...
... Large diameter part discharge port, 23 ... Small diameter part chamber, 24 ... Discharge valve, 25 ... Small diameter part discharge port, 26 ... Small diameter part suction port, 27 ... Suction valve, 28 ... Communication passage, 29 ...
...Switching switch (opening/closing means), 30... Branch road, 3
1...Pressure regulating valve (pressure regulating means).

Claims (1)

[Scope of utility model registration request] A reciprocating pump comprising a connecting rod 5 pivotally supported on the crankcase 1 via a crankshaft 4, and a piston means 11 connected to the tip of the connecting rod 5 with a pin and capable of reciprocating sliding within the cylinder body 8. The cylinder body 8 includes a cylinder large diameter part 6 and a cylinder small diameter part 7, and the cylinder large diameter part 6 and the cylinder small diameter part 7 include a piston large diameter part constituting the piston means 11. 9 and the piston small diameter part 10 are slid together in a water-tight manner through packings 13 and 14, respectively, and the piston large diameter part 9 and the piston small diameter part 10 are attached to the cylinder large diameter part 6.
A large-diameter chamber 18 is formed, and a large-diameter suction port 20 having a suction valve 19 and a large-diameter discharge port 22 having a discharge valve 21 are provided in the large-diameter chamber 18. A small diameter chamber 23 defined by the piston small diameter section 10 is formed on the tip side of the section 7, and a small diameter section discharge port 25 having a discharge valve 24 is provided in this small diameter section chamber 23. A cylindrical sleeve 10a is fitted loosely in the axial direction with a space maintained, and is slidably contacted with the packing 14, and a suction port 26 is provided at the tip of the small diameter portion 10 of the piston to prevent the sleeve 10a from coming off. Connecting the formed blocking members 10b,
A suction valve 27 is formed at the proximal end of the sleeve 10a, and the suction valve 27 can open and close the suction port 26 and the large diameter chamber 18 in communication with each other through the inside of the sleeve 10a, and a means 29 for opening and closing the small diameter discharge port 25 is provided. communicates with the large-diameter discharge port 22 through a communication passage 28, and
A reciprocating pump characterized in that a pressure regulating means 31 is connected to the outside via a branch passage 30 and is provided between the discharge side of the large-diameter discharge port 22 and the opening/closing means 29.