JPS59185881A - Hydraulic control unit for reciprocating double-row cylinder type positive displacement pump - Google Patents

Abstract

PURPOSE:To keep off any surge pressure as well as to secure such a hydraulic control unit as being longevity in service life, by attaching a pilot valve to both push and pull stroke end positions of a power cylinder at one side, while connecting a pilot port to a return oil system in a controlling valve. CONSTITUTION:Both push and pull stroke positions of a power cylinder 11 at one side are provided with each of pilot valves 15' and 16'. A pipe line 38 ranging from a pilot port H of a controlling valve 19B is connected to a port B of a power cylinder 19A, while a pipe line 41 ranging from a pilot port G is connected to a port A. With this constitution, in time of a piston 13 being in its push stroke, pressure oil inside the power cylinder 11 passes through the pipe line 38 from a port Q and then pushes a spool 23 at the pilot port H. At this time, oil at the opposite side of the spool 23 passes through each of pipe lines 41 and 43 from the port G and then returns to a tank running past a port A-T by way of a check valve 44.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hydraulic control system for a reciprocating double-row cylinder displacement pump for transporting highly viscous materials such as slurry.

A conventional pump of this type and a hydraulic control device for the pump sump are shown in FIG. The pump consists of a pump cylinder 1, 1', a pump piston 2.2', a piston rod 6.6', a suction valve 4, 4', an actuating cylinder 5, 5' of the suction valve, and an actuating cylinder 5, 5' of the suction valve. Piston 6.6'
, a discharge valve 7,7', and an actuating cylinder 8,8' of the discharge valve.
, its pistons 9 and 9', and a pump discharge port 10.

Operating cylinders 11 and 12 are connected to the pump cylinders 1 and 1', respectively, and operating pistons 16 and 14 are connected to the pump pistons 2 and 2', respectively, and piston rods 3 and 6 are connected to the pump cylinders 1 and 1', respectively.
′.

A pilot valve 15.16 is attached to each rod end of the operating cylinders 11, 12, and a hydraulic cushion 17.18 is attached to each opposite end. Details of a known pilot valve 15,16 are shown in FIG.

In FIG. 2, there are three boats R2S with a housing attached to one operating cylinder 11.

It has W. Inside the housing 101, a valve body 106 is biased by pressure oil from the boat W and the splash 104 so as to always close the boat R.

In FIG. 1, the operating valve 19 is composed of operating valves 19A and 19B having Sgures 20 and 21, respectively, and the line 24 connecting the two operating valves is connected to the tank, and the line 2
5 is connected to a separate hydraulic unit. The ends of the actuating cylinders 11, 12 opposite the piston rod are connected to the bows (B, A) of the actuating valve 19 via conduits 22, 25, respectively. The boat S of the pilot valve 15 of one operating cylinder 11 is connected to the pilot boat H of the operating valve 19B via a conduit 68, and the boat S' of the pilot valve 16 of the other operating cylinder 12 is connected to the pilot boat H of the operating valve 19B.
It is connected to the pilot bow 1-G on the opposite side. Further, the boat R of the pilot valve 15 of one operating cylinder 11 is connected to the boat Q of the operating cylinder 11 via the conduit 37.
and the pilot valve 1 of the other operating cylinder 12
6 boats R' are likewise connected via conduits 37' to boats Q' of the operating cylinder 12. Operation cylinder 1
The chamber 11a of the cylinder 1 and the chamber 12a of the operating cylinder 12 are connected to each other by a conduit 40 on the piston rod side.

The boat C of the operating valve 19B is connected to the port of the operating cylinder 8' of one discharge valve 7' via pipes 26 and 27, and is connected to the port of the operating cylinder 8' of the other discharge valve 7' via pipes 26 and 2B.
The working cylinder 8 is connected to the boat L. Conduit 2
6 is further connected via branch lines 28 and 29 to the boat N of the actuating cylinder 5' of the suction valve 4' and via a branch line 30 to the boat 1-o of the suction valve 4. .

Further, the bow) D of the operating valve 19B is connected to the boat K of the operating cylinder 8 of the discharge valve 7 via a pipe 31, and to the boat J of the discharge valve 7' via pipes 31 and 62. connected. Further, the pipe line 32 further includes a branch pipe line 3.
3 to the bow) P of the working cylinder 5 of the suction valve 4, and further connected to the port M of the working cylinder 5' of the suction valve 4' via a branch line 64. The pilot port E of the other operating valve 19A is connected to the pipe line 2 via the pipe line 35.
6, and the pilot port (F) is connected to the pipe line 31 via a pipe line 66.

At the position of the operating valve 19A in FIG. 1, pressure oil enters the operating cylinder 11 through the conduit 22, causing the piston 16 to perform a pushing stroke, and oil in the operating cylinder 12 returns to the tank via the conduit 23, causing the piston to move. 14 is performing the pulling stroke. Also,
At the position of the operation valve 19B, the pipe line 26 communicates with the separately installed pump unit, and the pipe line 31 communicates with the tank, so that the discharge valve 7' of one pump cylinder 1' is closed and the suction valve is closed. 4' is open, while the discharge valve 7 of the other pump cylinder 1 is open and the suction valve 4 is closed. When the piston 13 of the operating cylinder 11 crosses the ports 1-Q of the cylinder and reaches the end of its stroke, pressure oil enters the pilot valve 15 via the pipe 37, and flows from the port S to the operating valve 19B via the multiple pipes 38. Press the spool 21. This switches the operation valve 19B and returns the oil to the tank from the pipe 26, and the pressure oil from the separate hydraulic unit is transferred from the pipe 31 to the tank. Since the spool 20 of the other operating valve 19A is pushed through the passage 36, the operating valve 19A
is switched, pressure oil passes through the pipe 23 to the operating cylinder 12.
Once inside, the piston 14 performs a pushing stroke and, since the conduit 22 leads to the tank, the piston 16 of the operating cylinder 11 performs a pulling stroke. At this time, oil in the chamber 12a of the operating cylinder 12 enters the chamber 11a of the other operating cylinder 11 through the connecting pipe 40 and pushes the piston 13. at the same time,
Pressure oil in the pipe line 61 and return oil in the pipe line 26 and pump 1
The discharge valve 7 of the pump 1' is closed, the suction valve 4 is opened, and the pump 1' is closed.
The discharge valve 7' is opened and the suction valve 4' is closed. Thus,
Pump cylinder 1 performs a suction stroke, and pump cylinder 1
' performs a pushing stroke. Thereafter, this is repeated to cause the pump 7 cylinders 1, 1' to reciprocate.

However, in this hydraulic circuit, for example, when the piston 13 of one operating cylinder 11 reaches the stroke end indicated by the dotted line in FIG. (Fig.), and then connect the operating valve 1' from port S of the pilot valve 15 through the pipe 38.
9B's pilot port H is pressed, but since back pressure is coming from the cylinder port Q' to the port R' of the pilot valve 16 of the other operating cylinder 12, the port G side chamber of the operating valve 19B is pressed. There is no escape route for the oil that comes to the port S' of the pilot valve 16 via the passage 39, and some of the oil flows into the valve body 1.
After the oil is compressed to the maximum while leaking through the gap 06 and into the operating cylinder through port W, the switching occurs.

As a result, as the piston speed increases, the spool 21 of the operating valve 19B may switch before reaching the complete end switching position, or the spool 21 may suddenly move suddenly and switch, and its operation may become smooth. As a result, the piston causes knocking during switching, and the operating valve 19B switches when the piston of the other operating cylinder has not reached the stroke end position, and as a result, the pistons 13, 1
4. There is a drawback that the suction valves 4, 4' and the discharge valves 7, 7' do not complete their respective strokes. Furthermore, surge pressure is generated due to the relationship between the oil in the chamber on the boat G side of the operating valve 19B and the operating cylinder, which leads to surge pressure in the entire hydraulic system, which shortens the life of each part. was there.

An object of the present invention is to eliminate the above-mentioned drawbacks, to ensure that the pistons of both operating cylinders are operated to their stroke end positions, to ensure reliable switching of the suction and discharge valves, and to reduce surge pressure. It is an object of the present invention to provide a hydraulic control device for a reciprocating double-row cylinder type positive displacement pump that can prevent the occurrence of such problems and extend the life of each part.

An embodiment of the present invention will be described below with reference to FIG. In FIG. 3, the same parts as in FIG. 1 are given the same reference numerals.

According to the present invention, pilot valves 15 are provided at both the pushing stroke end position and the pulling stroke end position of one operating cylinder 11.
' and 16').

A pilot valve used in the present invention is shown in FIG. In FIG. 4, 101' is a housing attached to the operating cylinder 11, which has three bows 1-R.

It has S and W. 102' is a pilot guide inserted into a hole in the puffer fish 101', and has holes communicating with ports R and S. Inside the pilot guide 102', a valve body 103' is biased by pressure oil from the valve W and a spring 104' so as to always close the port R. As a result, the operating syringe 11 moves to both stroke end positions.

Further, the port S of the pilot operated valve 15' is connected to one pilot boat (H) of the operating valve 19B via a conduit 68, and the outlet side boat sl of the pilot operated valve 16' is connected via a conduit 41. and is connected to the pilot boat G on the opposite side of the same operating valve 19B. According to the present invention, the pipe line 68 from the pilot port H of the operating valve 19B further passes through the branch pipe line 42 to the operating cylinder 19.
A pipe line 41 from the pilot port G of the operating valve 19B passes through a branch pipe line 43 to the operating valve 19B.
A's bow) is connected to A. Note that 44 indicates a reverse valve. As a result, the piston 13 of the operating cylinder 11 comes to the stroke end position indicated by the dotted line during the pushing stroke, and the operating cylinder 11
The pressure oil in the cylinder is transferred from the port Q of the cylinder to the pilot valve 15.
) Pass through R and S, pipe 38, and operation valve 19B.
When pressing the spool 23 with the pilot bow) H,
The oil filling the opposite side of the spool 26 is
It can be returned to the tank through the pipes 41 and 43, and then through the check valve 44 and through the control valve j9A's bow) AT. When the spool 26 of the operating valve 19B is in the opposite position to that shown in FIG. 6 and the piston 16 of the operating cylinder 11 is at the end of the retracting stroke, the spool 23 similarly moves to exit from the pilot port H. The oil in the operation valve 19B is transferred to the pipes 38, 42, the check valve 44, and the control valve 19A.
It can be returned to the tank from T (at this time, the spool of the operating valve 19A is also in a position opposite to that in FIG. 6).

Cushion valves 17 and 18 are provided at the pushing stroke end position and the pulling stroke end position of the piston 14 of the other operating cylinder 12, respectively.
It is desirable to provide The cushion valves 17 and 18 are arranged so that when the piston 14 is in the pushing stroke, one chamber 121) of the operating cylinder 12 is connected to the opposite chamber 12a via the port UV of the hydraulic cushion valve 17 just before the end of the stroke. Pressure oil flows from the chamber 121) to the chamber 12a in communication, providing a cushioning effect and serving to replenish the oil shortage in the chamber 12a connecting pipe 40-chamber 11a.

Further, the cushion valve 18 for the pulling stroke is connected to one chamber 1 of the operating cylinder 12 immediately before the end of the pulling stroke of the piston 14.
Pressure oil flows from 2a to port Utv of cushion valve 18.
It flows into the opposite chamber 12b through the chamber 12b and acts as a cushion, and also serves to draw out excess oil in the chamber 11a.

Furthermore, according to the invention, the ports C and D of the operating valve 19B are connected to the hydraulic pressure including the actuating cylinders 5, 5' and 8°8' of the suction valves 4, 4' and the discharge valves 7, 7' of the pump, respectively. Two pipe lines 26 are connected to the system 45.

The properties of the material to be transported, the diameter and length of the transport pipe, etc., and the operation cylinder 11.1
The hydraulic pressure required for 2 is different. When there is no pressure reducing valve 46 as in the prior art shown in FIG.
2. Suction valve and discharge valve actuation cylinder 5, '5',
Since the same pressure is applied to all the pistons 13.8 and 8', the pistons 13. As the pressure required to press i4 becomes higher, the pressure for switching the suction valve 4, 4' and the discharge valves 7, 7' also increases.

These suction valves and discharge valves are often switched several to several times per minute, and each time the metal surfaces come into contact with each other, so as the pressure increases, the wear increases. However, with the pressure reducing valve 46 of the present invention, even if the pressure required in the actuating cylinder 11, 12 is higher, the pressure higher than the set pressure of the pressure reducing valve 46 will remain In addition to the discharge valves 7, 7', the pump's suction valves 4, 4' and discharge valves 7,
7' requires a quick movement when closing the conveyed article passage in order to prevent a backflow of the conveyed article, but does not require a very rapid outward movement during the opening operation. According to the invention, therefore, the actuating cylinders 5, 5' of the suction and discharge valves,
8, 8' piston rod side end bow 1-N,
Throttle valves 47 are installed in the hydraulic pipes connected to P, J, and L, respectively.
By providing a piston 6.6' of the suction valve and the discharge valve, the movement of the suction valve and the discharge valve in the opening operation is slowed down.
9.9' pistons and the parts of the working cylinders 5, 5', 8, 8' against which these pistons rest can be protected.

In the present invention, the pilot valves are installed at the push stroke end position and the pull stroke end position of one operating cylinder, and the pilot ports at both ends of the operating cylinder are connected to the return oil system of the operating valve, so that one When the pilot valve operates and pushes the spool of the operating valve at the end of the stroke of the operating cylinder, the oil filling the chamber on the opposite side of the spool of the operating valve is immediately returned to the return oil system of the operating valve. . As a result, the operating valves are switched smoothly, so the pistons of both operating cylinders operate reliably to both stroke end positions, and the suction and discharge valves are also switched reliably. Since no pressure is generated, there are many advantages such as a longer lifespan for each component.

[Brief explanation of the drawing]

Fig. 1 shows a conventional hydraulic control circuit for a reciprocating double-row cylinder slurry pump sump, and Fig. 2 shows a hydraulic control circuit installed at the end of stroke of the operating cylinder to switch the operating valve at the end of stroke of the operating cylinder. Detailed sectional view of the known pilot valve, FIG. 3 shows the hydraulic pressure according to the invention for a slurry pump 4.4'...suction valve 5, 5'; 8, 8'... working cylinder 7.7'
...Discharge valve 11...One operation cylinder 12...Other operation cylinder 15', 16'...Pilot valve 17.18...Cushion valve 19...Operation valve 46...Pressure reduction Valve 47...throttle valve

Claims (1)

[Claims] (1) Two operation cylinders each connected in series to two pump cylinders for pumping a highly viscous material and connected to each other, and a conduit connected to these operation cylinders. The pilot port of the operating valve is provided with a connected operating valve and a pilot valve installed at the stroke end position of the operating cylinder, such that the pilot valve switches the operating valve when the piston of the operating cylinder reaches the stroke end position. In a hydraulic control device for a reciprocating double-row cylinder type positive displacement pump, which is connected by a pipe to one operating cylinder (11
) are installed at the push stroke end position and pull stroke end position, respectively, and the pilot ports (G, H) at both ends of the operation valve (19B) are connected to the return port of the operation valve. A device characterized by being connected to an oil system. (2) Two operating cylinders each connected in series to two pump cylinders for pumping highly viscous materials and mutually connected, an operating valve connected to these operating cylinders by a conduit, and an operating cylinder. and a pilot valve installed at the stroke end position, and the pilot valve is connected to the pilot port of the operating valve by a conduit so that the pilot valve switches the operating valve when the piston of the operating cylinder reaches the stroke end, and the pilot valve is connected to the pilot port of the operating valve so that one operating A pilot valve (15') is installed at both the pushing stroke end position and the pulling stroke end position of the cylinder (11).
, 16') is installed, the operating valve (1) is connected to the operating cylinder (5) of the suction valve and discharge valve of the pump cylinder (1+1'). , 5';13.El') is installed in the hydraulic line connected to the hydraulic system (45), so that even if high pressure is applied to the p-operated cylinder hydraulic system, the blowing A device characterized in that an unnecessarily high pressure is not applied to the hydraulic system (45) including the operating cylinders of the valve and discharge valve. The piston of the operating cylinder is equipped with two operating cylinders connected to each other and connected to each other, an operating valve connected to these operating cylinders by a conduit, and a pilot valve installed at the end of the stroke of the operating cylinder. When the end of stroke is reached, the pilot valve is connected to the pilot boat of the operating valve (by a conduit) to switch the operating valve, and one operating cylinder (one in both the push and pull end positions) Pilot valve (15',
In a hydraulic control device for a reciprocating double-row cylinder-type displacement pump, in which a reciprocating double-row cylinder displacement pump is installed, the piston rod side end of each suction valve and discharge valve actuating cylinder (5, 5'; 8, 8') A device characterized in that a restrictor valve (47) is provided in each of the hydraulic lines connected to the part, thereby preventing damage to the valve bodies of the suction valve and the discharge valve.