JPS5916103B2 - Hydraulic actuation device for piston pump for fluid pumping - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a piston pump for pumping a fluid and a hydraulically actuated device comprising a pair of pump cylinders each having a pump piston that is alternately driven back and forth by the driving force of a corresponding hydraulic cylinder for pump driving. It is related to.

Conventionally, a pair of pump cylinders each include a pump piston that is alternately driven back and forth by the driving force of a corresponding pump driving hydraulic cylinder, and each pump cylinder alternately introduces the fluid discharged into a discharge pipe. In a piston pump for fluid pumping, which has a pulp actuated by a pulp actuating hydraulic cylinder for alternately connecting each pump cylinder to the discharge pipe in synchronization with the actuation of each pump piston, a pulp switching operation is performed. and the switching operation of the switching valve for switching and supplying pressure oil to the hydraulic cylinder for driving the pump are operated in sequence, so that the pulp and each pump piston are operated in a related manner. Even after the switching operation is completed, there is a time delay before the pump piston starts to drive in response, making it impossible to operate the device efficiently.

The present invention has been made in view of the above, and is a hydraulic actuation device for a piston pump for pumping fluid, which has a simple structure and high durability, can eliminate the problems of the conventional ones, and can operate quietly. The purpose is to provide the following.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.A pair of pump cylinders 1, 1' are respectively connected with pump driving hydraulic cylinders 2, 2'. Each is provided with a control valve 3, 3'.

Pump piston 414' in each pump cylinder 1,1'
&-1, are integrally connected to hydraulic pistons 5, 5' in respective hydraulic cylinders 2, 2' via rods 6°6'.

Each control valve 3゜3' has low-pressure side ports) L, L' and high-pressure side ports) H, H', and is normally switched to the lower side of the figure. However, when the hydraulic pistons 5, 5' move from the suction state to the discharge state and come closest to the base end of each hydraulic cylinder 2, 2', they are switched to the upper side of the figure. and put the high pressure side ports) H and H' in communication, and each hydraulic piston 5, 5'
When it leaves the base end of each hydraulic cylinder 2, 2', it is switched downward again to place the low pressure side ports L, L' in communication.

A common pulp chamber 7 is provided at the tip of each pump cylinder 1, 1', and the pulp 8 in this pulp chamber T is reciprocated by a pulp operating hydraulic cylinder 9, so that the pump piston 4° 4', the pump cylinder 1 and the discharge pipe 10. Alternatively, the pump cylinder 1' and the discharge pipe 10 are configured to communicate with each other alternately.

Pressure oil pumped up from the oil tank T by the hydraulic pump P is sent to the main switching valve 11 via the oil path 1B, and the main switching valve 11
The waste oil discharged from the tank is returned to the oil tank T via an oil passage 19.

A pair of oil passages 20 and 23 further come out from the main switching valve 11, and oil passages 21 and 24 branched from the oil passages 20 and 23 are for driving a pump each having a pair of pilot oil chambers 13 and 14. Another oil passage 22.25 that is in communication with the automatic switching valve 12 and branched from the oil passages 20 and 23 is connected to an automatic switching valve 15 for pulp operation that is provided with a pair of pilot oil chambers 16 and 17, respectively. ing.

Another pair of oil passages 26 and 27 coming out of the automatic switching valve 12 communicate with the base chambers of the hydraulic cylinders 2 and 2', respectively.
In addition, another pair of oil passages 29.3 coming out from the automatic switching valve 15
0 communicate with the base chamber and tip chamber of the hydraulic cylinder 90, respectively.

The front chambers of each hydraulic cylinder 2, 2' are communicated with each other by an oil passage 28.
When pressure oil is introduced into the base chamber of the hydraulic piston 5 and moves toward the tip side, the pressure oil in the tip chamber of the hydraulic cylinder 2 flows into the tip chamber of the hydraulic cylinder 2' through the oil passage 28,
Press the hydraulic piston 5/ toward the base.

The hydraulic oil in the base chamber of the hydraulic cylinder 2' is supplied to the oil passage 2.
It is discharged after 7.

Further, when pressure oil is introduced into the base chamber of the hydraulic cylinder 10 through the oil passage 27 and moves toward the tip side of the hydraulic piston 5, the pressure oil in the front chamber of the hydraulic cylinder 2' passes through the oil passage 2B and enters the hydraulic cylinder 2. flows into the tip chamber of the hydraulic piston 5.
Press toward the base.

The hydraulic oil in the base chamber of the hydraulic cylinder 20 flows through the oil passage 26.
It is designed to be discharged through the process.

An oil passage 31 branches from the part of the oil passage 18 that pumps high-pressure oil, and this oil passage 31 further branches into oil passages 32 and 33, which are then connected to the high-pressure side ports of the control valves 3 and 3' respectively. H,
It communicates with H'.

Further, an oil passage 34 branches from the oil passage 19 that recirculates waste oil, and this oil passage 34 further branches into oil passages 35 and 36, and then the low pressure side ports L of the control valves 3 and 3', respectively. , L
’.

From each control valve 3, 3' there is an oil passage 31°38, respectively.
These oil passages 37 and 3B communicate with the pilot oil chambers 16 and 17 of the automatic switching valve 15, respectively.

Further, oil passages 39 and 41 are branched from each oil passage 29 and 30, respectively, and these oil passages 39 and 41 are connected to a pilot as a switching operation part of the automatic switching valve 12 through orifices 40 and 42, respectively. It communicates with the oil chamber 14.13.

A high pressure adjustment device 43 is attached to the oil passage 18, and when the oil pressure in the oil passage 18 becomes higher than the set pressure, the high pressure adjustment device 43 adjusts the pressure oil in the oil passage 18 to the set oil pressure. It is designed to discharge until the pressure drops.

With the above structure, when the main switching valve 11 is switched to the left in the illustrated state, the pressure oil coming out of the hydraulic pump P is transferred to the oil passage 1B, the main switching valve 11, the oil passage 20, and the oil passage 2.
1 and 22, and is sent to the automatic switching valve 12.15.

At the same time, the pressure oil in the oil passage 18 is sent to the high pressure side ports H, m of the control valve 3° 3' via the oil passages 31, 32, 33.

In this state, the pressure oil that has passed through the automatic switching valve 15 is introduced into the front chamber of the hydraulic cylinder 9 through the oil path 30, drives the hydraulic cylinder 9, moves the pulp 8 toward the pump cylinder 1', and moves the pulp 8 toward the pump cylinder 1'. 1 and the discharge pipe 10 are communicated with each other.

Simultaneously with the start of driving of the hydraulic cylinder 9, the pressure oil in the oil passage 30 is introduced into the pilot oil chamber 13 via the pilot oil passage 41, but due to the throttling action of the orifice 42, the automatic switching valve 12 The switch is slowly switched to the left during a predetermined time period that corresponds to the time required for the switch operation.

During this time, the hydraulic oil in the base chamber of the hydraulic cylinder 9 flows through the oil passage 29.
．． The hydraulic oil in the pilot oil chamber 14 is returned to the oil tank T via the automatic switching valve 15, oil passage 25, 23, main switching valve 11, and oil passage 19, and the hydraulic oil in the pilot oil chamber 14 is discharged into the oil passage 29 via the oil passage 39. .

When the automatic switching valve 12 is switched to the left side, the pressure oil in the oil passage 21 is introduced into the base chamber of the hydraulic cylinder 2 via the automatic switching valve 12 and the oil passage 26, and the hydraulic piston 5 and therefore the pump piston 4 are first Move to the department side.

At the same time, the hydraulic oil in the front chamber of the hydraulic cylinder 2 flows through the oil passage 28.
It is press-fitted into the front chamber of the hydraulic cylinder 2' through
The hydraulic piston 5' and thus the pump piston 4' are moved proximally.

During this time, the hydraulic oil in the base chamber of the hydraulic cylinder 2' is discharged into the oil passage 23 via the oil passage 27, the automatic switching valve 12, and the oil passage 24.

In this state, the pump cylinder 1 in the suction state
′ sucks in fluid such as concrete or sludge through a suction port (not shown), and the pump cylinder 1 in the discharge state discharges the fluid into the discharge pipe 10 through the pulp 8.

When the hydraulic piston 5' approaches the base end of the hydraulic cylinder 2', the control valve 3' is switched upward, and the pressure oil in the oil passage 33 is transferred to the high pressure side port H', the control valve 3', and the oil passage 38. The oil is introduced into the pilot oil chamber 17 through the passageway, and switches the automatic switching valve 15 to the left side.

During this time, the hydraulic oil in the pilot oil chamber 16 flows through the oil passage 37,
It is discharged into the oil passage 19 via the control valve 3, the low pressure side port) L, and the oil passages 35 and 34.

When the automatic switching valve 15 is switched to the left side, the pressure oil in the oil passage 22 is introduced into the base chamber of the hydraulic cylinder 9 through the automatic switching valve 15 and the oil passage 29, and drives the hydraulic cylinder 9 to produce pulp 8. Activate.

The pulp 8 moves towards the pump piston 1 in reverse of its previous movement and now connects the pump cylinder 1' with the discharge pipe 10.

Simultaneously with the start of reverse drive of the hydraulic cylinder 9, the oil passage 29
The pressure oil inside passes through the pilot oil passage 39 to the pilot oil chamber 1.
4, but due to the throttling action of the orifice 40, the automatic switching valve 12.

The switching operation is slowly performed to the right during a predetermined time set corresponding to the time required for the switching operation of the pulp 8.

During this time, the hydraulic oil in the front chamber of the hydraulic cylinder 9 flows through the oil path 3.
0, automatic switching valve 15, oil passage 25.23, main switching valve 11,
The hydraulic oil in the pilot oil chamber 13 is returned to the oil tank T via the oil passage 19 and discharged into the oil passage 30 via the oil passage 41 .

When the automatic switching valve 12 is switched to the right side, the pressure oil in the oil passage 21 is introduced into the base chamber of the hydraulic cylinder 2' through the automatic switching valve 12 and the oil passage 27, and the hydraulic oil is introduced into the base chamber of the hydraulic cylinder 2', and the hydraulic piston 5' and therefore the pump cylinder end. Press and move to the side.

At the same time, the hydraulic oil in the front chamber of the hydraulic cylinder 1 flows through the oil passage 28.
is introduced into the front end chamber of the hydraulic cylinder 2 through the hydraulic piston 5. Therefore, the pump piston 4 is moved toward the base.

During this time, the hydraulic oil in the base chamber of the hydraulic cylinder 2 flows through the oil passage 2.
6. The oil is discharged into the oil passage 23 via the automatic switching valve 12 and the oil passage 24.

In this state, the pump cylinder 1 in the suction state
The pump cylinder 1' sucks in a fluid such as concrete or sludge through a suction port (not shown), and the pump cylinder 1' in a discharge state discharges the fluid into the discharge pipe 10 through the pulp 8.

When the hydraulic piston 5 approaches the base end of the hydraulic cylinder 20, the control valve 3 is switched to the upper side, and the pressure oil in the oil passage 32 is transferred to the pilot oil chamber 16 via the high pressure side control valve 3 and the oil passage 37. the automatic switching valve 15 to the right of its initial position.

During this time, the hydraulic oil in the pilot oil chamber 17 and the oil passage 38
, the control valve 3, the low pressure side port L', and the oil passage 36°34, and are discharged into the oil passage 19.

Thereafter, as the above-described circulation operation is automatically repeated in sequence, the suction and discharge operation of the fluid by the pair of pump cylinders 1.about.1' is alternately repeated.

As long as the main switching valve 11 is switched to the left, the pulp 8
is moved to the side of the pump cylinder 1' and the pump cylinder 1 and the discharge pipe 10 are communicated with each other, the pump cylinder 1 enters the discharge state and the pump cylinder 1' enters the suction state, and the pulp 8 enters the pump When the pump cylinder 1' is moved to the side of the cylinder 1 and the pump cylinder 1' and the discharge pipe 10 are communicated with each other, the pump cylinder 1 enters the suction state and the pump cylinder 1' enters the discharge state, and the fluid always flows through the discharge pipe 10.
It is discharged through 0.

However, the fluid does not necessarily have good fluidity, and foreign contaminants may be mixed into the fluid.

Due to this, if the discharge pipe 10 or the transport pipe connected to the discharge pipe 10 is long, clogging may occur in the discharge pipe 10 or the transport pipe, which may impede the pumping of the fluid. may occur.

In such a case, the phenomenon of clogging in the discharge pipe 10 or the transport pipe can be eliminated by temporarily causing the fluid to flow backwards.

When it is necessary to reverse the flow of fluid, the main switching valve 1
1 to the right side in the figure, the oil passage 18 becomes the oil passage 23.
Since the oil passage 19 communicates with the oil passage 20, as is clear from the above operation description and drawings, the operation of the hydraulic cylinder 9 and the operation of the hydraulic cylinders 2 and 7 are carried out through the discharge pipe 10. Unlike the operation when pumping fluids,
They operate in opposition to each other.

That is, when the pulp 8 is moved to the side of the pump cylinder 1' and the pump cylinder 1 and the discharge pipe 10 are communicated with each other,
The pump cylinder 1 enters the suction state, and the pump cylinder 1' enters the discharge state, and when the pulp 8 is moved to the side of the pump cylinder 1 and the pump cylinder 1' and the discharge pipe 10 are communicated, the pump Cylinder 1 enters the discharge state and pump cylinder 1' enters the suction state,
The fluid in the discharge pipe 10 and the transport pipe can be caused to flow back.

As is clear from the above description, according to the present invention, the control means for switching the automatic switching valve 12 for pump drive in connection with the operation of the hydraulic cylinder 9 for pulp operation is controlled between the two of the hydraulic cylinders 9 for pulp operation. A pair of pilot oil passages 39° 41 that constantly communicate the two hydraulic chambers and the switching operation part of the automatic switching valve 12 for pump drive;
A pair of orifices 40 and 42 respectively provided in 41
Accordingly, a part of the hydraulic oil switched and supplied to the pulp operating hydraulic cylinder 9 in accordance with the switching operation of the pulp operating automatic switching valve 15 is subjected to the throttling action of the orifice 40, 42, and the pump is driven. reaches the switching operation part of the automatic switching valve 12 for driving the pump, and at that time, the pressure in the switching operation part gradually increases, so that the automatic switching valve 12 for driving the pump
Therefore, there is no risk of causing a shock when switching the pump drive automatic switching valve 12, and the switching operation can be carried out quietly from start to finish, and the durability of the switching valve 1 and 2 itself can be improved. can be increased.

Moreover, the switching operation of the automatic switching valve 12 for driving the pump,
Since it can be performed simultaneously with the pulp 8 switching operation by the pulp operating hydraulic cylinder 9, the pulp 8 switching operation takes a relatively long time due to the handling of highly viscous fluids such as fresh concrete in this type of equipment. The working time for switching the automatic switching valve 12 for driving the pump can be effectively used for switching the automatic switching valve 12 for driving the pump.
By appropriately selecting 2, it is possible to start driving the pump cylinder 1 or 1' in synchronization with the completion of the switching operation of the pulp 8. Therefore, the device can continue to operate extremely efficiently, and the fluid can be pumped efficiently. can do.

Furthermore, there is no need to interpose a plurality of sequence pulps in the pilot oil passages 39, 41 as in conventional devices of this type, and the orifice 40.4 has a simple structure.
24: Since it is sufficient to simply provide it, it is possible to simplify the configuration of the hydraulic circuit as much as possible, reduce costs, and reduce the occurrence of failures.

Further, since the automatic switching valve 15 for pulp operation is a switching valve for directly introducing hydraulic oil into the hydraulic cylinder 9 for pulp operation, the structure inevitably increases in size.
Relatively small control valves 3, 3' for switching operation of the pump cylinders 1, 1' are provided within the pump cylinders 1, 1', and the switching valves 15 themselves are provided separately from the pump cylinders 1, 1'. Therefore, the control valve 3 into the pump cylinders 1, 1'
, 3'a included is structurally reasonable, and pump cylinder 1
, 1' need not be increased in size unnecessarily, and the cost increase can be suppressed.

[Brief explanation of the drawing]

The figure is an overall conceptual explanatory diagram of a hydraulic actuation device for a piston pump for pumping fluid, showing one embodiment of the present invention. 1.1' is a pump cylinder, 2, 2' are hydraulic cylinders for driving the pump, 3, 3' are control valves, 4, 4' are pump pistons, 8 is pulp, 9 is a hydraulic cylinder for pulp operation, 1
0 is the discharge pipe, 12 is the automatic switching valve for pump drive, 15 is the automatic switching valve for pulp operation, 39°41 is pilot oil L4
0.42 is the orifice, and P is the hydraulic pressure source.

Claims (1)

[Claims] 1 a pair of pump cylinders 1, 1' each with a pump piston 4, 4';
1'; pump driving hydraulic cylinders 2, 2' equipped with driving pistons 5, 5' that are connected to the pump pistons 1' and alternately reciprocate the pump pistons 4, 4';
, 1' is interposed between the pump cylinders 1, 1' and the discharge pipe 10, and - the pair of pump cylinders 1, 1' are connected to the discharge pipe 10. It is equipped with pulps 8 which communicate with each other alternately; and a pulp operating hydraulic cylinder 9 which is connected to this pulp 8 and drives it back and forth, and which operates the pulp 8 in synchronization with the operation of the pump pistons 4 and 4'. , a piston pump for pumping fluid, in which each pump cylinder 1, 1' is alternately connected to a discharge pipe 10, and the fluid alternately discharged by each pump cylinder 1, 1' is introduced into the discharge pipe 10. In hydraulic actuators,
a pump driving automatic switching valve 12 for alternately supplying pressure oil sent from the hydraulic source P to each of the pump driving hydraulic cylinders 2, 2'; an automatic switching valve 15 for pulp operation for alternately supplying pulp to the two hydraulic chambers of the operating hydraulic cylinder 9; provided in each of the pump cylinders 1, 1', and for operating the respective pump cylinders 1, 1'; a pair of control valves 3.3' for switching the automatic switching valve 15 for pulp operation in connection with the operation; control for switching the automatic switching valve 12 for driving the pump in connection with the operation of the hydraulic cylinder 9 for pulp operation; The control means includes two hydraulic chambers of the pulp operating hydraulic cylinder 9 and a pump driving automatic switching valve 1.
It is composed of a pair of pilot oil passages 39, 41 which are in constant communication with the switching operation parts of 2, and a pair of orifices 40° 420 provided in the pilot oil passages 39, 41 respectively, and these orifices 40° 420, A fluid that allows the pump driving automatic switching valve 12 to slowly start switching operation before the pulp operating hydraulic cylinder 9 completes the valve 8 switching operation by a throttling action on the pilot oil passages 39 and 41. Hydraulic actuation device for pressure piston pump.