JPH0893636A - Hydraulic circuit of swinging valve type concrete pump - Google Patents

Abstract

PURPOSE: To provide a hydraulic circuit of a swinging valve type concrete pump by which movements of swinging cylinders are stopped when a cleaning pipe is made to leap up so that concrete forcibly feeding cylinders are cleaned. CONSTITUTION: An accumulator 26 and a swing switching valve 27 are provided in order from the upstream side of a pressure oil line 24 in the pressure oil line 24 to swinging cylinders 14, 15. A main switching valve 21 is provided in a pressure oil supply/exhaust line 20 which makes two concrete foreibly feeding cylinders 3 to operate. One end of an auxiliay pilot line 40 is connected to one side pilot line 30a which makes switching pressure to be branched from a pilot line 28 to switch the main switching valve 21 so as to act on the swing switching valve 27. A shuttle valve 36 is assembled in a connecting part to connect both pilot lines 30a, 40 to each other. The other end of the auxiliary pilot line 40 is connected to a line 37 taken out from the upper stream position of the accumulator 26 in the pressure oil line 24 through a switching valve 38 for releasing pressure. The pressure in the accumulator 26 is introduced on the line 37 side by the operation of the switching valve 38 for releasing pressure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a swing valve in which a swing pipe as a suction / discharge valve housed in a concrete hopper is swung left and right to switch suction and discharge of concrete or the like in the hopper. The present invention relates to a hydraulic circuit of a concrete pump.

[0002]

2. Description of the Related Art A concrete pump in which concrete in a hopper is alternately sucked and discharged by two concrete pressure-feeding cylinders has a slide valve type as a suction and discharge valve for switching suction and discharge. Conventionally, a swing valve type is known.

As shown in FIGS. 2 and 3, a conventional concrete pump having a swing valve type suction and discharge valve has a hopper 1 as shown in FIG.
In the lower part of the front side wall of the, two intake and discharge ports 2 are provided side by side,
Outside the hopper 1, two concrete pressure-feeding cylinders 3 and 4 which communicate with the above-mentioned two suction and discharge ports 2 are installed in parallel, and the concrete pressure-feeding cylinders 3 and 4 housed in the respective concrete pressure-feeding cylinders 3 and 4 are used. The piston 5 is integrally connected to the main hydraulic pistons 9 in the main hydraulic cylinders 7 and 8 which are connected to the concrete pressure-feeding cylinders 3 and 4 through the cleaning chamber 6 via one rod 10 each. By alternately advancing and retracting the main hydraulic pistons 9 in the hydraulic cylinders 7 and 8, the concrete pumping piston 5 is alternately advanced and retracted. In addition, an oscillating tube 11 bent in an S shape is located in the hopper 1, and a seal ring 12 is attached to the front end of the oscillating tube 11 so that the two intake and discharge ports 2 can be alternately aligned. At the same time, the end of the rocking tube 11 is connected to the transport tube by penetrating the back surface of the hopper 1, and the connecting shaft 13 fixed in the middle of the rocking tube 11 is installed outside the hopper 1. Rocking cylinder 1
4, 15 are connected via an operating lever 16 and the operating lever 16 is tilted to the left and right so that the rocking tube 11 can be rocked in the lateral direction about the connecting shaft 13.

When the concrete 17 in the hopper 1 is sucked and discharged by the concrete pump, the front end of the rocking pipe 11 is sucked and discharged from the concrete pumping cylinder 3 which has already sucked the concrete in the hopper 1. Two
After that, the concrete pumping piston 5 in the concrete pumping cylinder 3 is advanced by the main hydraulic cylinder 7 to discharge the concrete 17 in the concrete pumping cylinder 3 through the rocking pipe 11, and at the same time, Another concrete pressure-feeding cylinder 4 retracts the concrete pressure-feeding piston 5 so that the concrete 17 in the hopper 1 is sucked through the suction / discharge port 2, and then the rocking pipe 11 corresponds to the concrete pressure-feeding cylinder 4. The concrete pressure-feeding cylinder 4 is swung to the suction / discharge port 2 side to advance and discharge the concrete.
After that, the rocking of the rocking pipe 11 and the forward and backward movements of the pressure-feeding cylinders 3 and 4 are alternately performed, whereby the concrete 17
Is continuously sucked and discharged through the swing tube 11.

In the above concrete pump, two main hydraulic cylinders 7 and 8 and two rocking cylinders 14 and 15 are used.
The hydraulic circuit for operating and at the required timing is
This is as shown in FIG. That is, the main oil pump 1
8 and the tank 19 and a pressure oil supply / discharge line 20 connecting the head-side pressure chambers of the two main hydraulic cylinders 7 and 8 with a main switching valve 21 provided between the main hydraulic cylinders 7 and 8. The rod-side pressure chambers are connected to each other by the sealed circuit 22, and the pressure oil discharged from the main oil pump 18 is alternately supplied to the head-side pressure chambers of the main hydraulic cylinders 7 and 8 by switching the main switching valve 21. By alternately moving the main hydraulic piston 9 in the hydraulic cylinder 7 and the main hydraulic piston 9 in the main hydraulic cylinder 8 forward and backward, the two concrete pressure feeding cylinders 3 and 4 are alternately switched to the suction side and the discharge side. The concrete 17 in the hopper 1 can be sucked and discharged. Also, two swing cylinders 14
An unload valve 25, an accumulator 26, and a swing switching valve 27 are provided in this order from the upstream side in the middle of a pressure oil line 24 that supplies pressure oil from the secondary oil pump 23 to 15 and 15, and the swing switching valve 27 is switched. Thus, the rocking cylinders 14 and 15 are alternately expanded and contracted to rock the rocking tube 11 left and right.

In addition, a boost valve 29, is provided in the middle of a pilot line 28 connecting the upstream position of the accumulator 26 of the pressure oil line 24 and the switching operation portion of the main switching valve 21.
Reversing valve 33a is provided, and branch pilot lines 30a and 30b branched from a position downstream of boost valve 29 of pilot line 28 are connected to the switching operation portion of rocking switching valve 27, and pressure oil line 24 is further connected. Another pilot line 31 taken out from the middle of the main hydraulic cylinder 7 or 8 is introduced to the switching operation portion of the boost valve 29 via the pilot switching valve 32 for the main hydraulic cylinders 7 and 8 and the reverse rotation valve 33b. When the main hydraulic piston 9 moves forward to the stroke end, the pilot switching valve 32 is switched by a command from the switch, and the boost valve 29 is switched by the pilot pressure.

Therefore, as shown in FIG. 4, when the switching valves 21 and 27 are switched as shown, the pressure oil from the main oil pump 18 is supplied to the head side of the main hydraulic cylinder 7. Therefore, the main hydraulic cylinder 7 is moved forward and the main hydraulic cylinder 8 is moved backward. On the other hand, the pressure oil from the auxiliary oil pump 23 is supplied to the rocking cylinder 14 from the pressure oil line 24 to rock the rocking pipe.

From this state, when the main hydraulic piston 9 of the main hydraulic cylinder 7 further advances and reaches the stroke end portion to switch the pilot switching valve 32, the pilot pressure on the upstream side of the pressure oil line 24 is changed from the pilot line 31. Pilot switching valve 32 and reversing valve 33 on the main hydraulic cylinder 7 side
It acts on the switching operation part of the boost valve 29 on the port a side via b, and switches the boost valve 29 to the port a. As a result, the pilot pressure acting through the pilot line 28 acts on the switching operation portion on the port a side of the main switching valve 21 via the port a of the boost valve 29 and the reversing valve 33a. Simultaneously with switching to a, the swing switching valve 27 is switched from the pilot line 30a to the port a side, so that the main hydraulic cylinder 8 is advanced and the swing cylinder 15 is extended to switch the swing pipe. By switching the pilot switching valve 32, forward / backward movement of the main hydraulic cylinders 7 and 8 and switching of the swing cylinders 14 and 15 are automatically performed.

In the rocking valve type concrete pump described above, when the concrete pumping work is completed and the insides of the concrete pumping cylinders 3 and 4 need to be cleaned, conventionally, after the concrete pump is stopped, As shown in FIG. 5, the transportation pipe connected to the end of the rocking pipe 11 is removed, the cleaning nozzle 34 is inserted into the rocking pipe 11 from the end of the rocking pipe 11, and the concrete pump is operated again. While swinging the swing pipe 11 and moving the pistons 5 of the concrete pressure-feeding cylinders 3 and 4 back and forth,
The cleaning water sprayed from the cleaning nozzle 34 is used as the rocking tube 1.
Although it was made to feed into the concrete pressure-feeding cylinders 3 and 4 through 1, in the case of such a cleaning system, since the rocking | fluctuation pipe 11 is performing rocking motion, It was not possible to carry out the washing work while watching the washing situation.

Therefore, recently, as shown in FIG. 6, the clutch 3 is provided between the connecting shaft 13 of the rocking tube 11 and the operating lever 16.
5, the operation lever 1 is operated by operating the clutch 35.
A method of directly washing the concrete pressure-feeding cylinders 3 and 4 while observing the internal state is considered in which the rocking pipe 11 is flipped up without removing the transport pipe by removing the connection between 6 and the connecting shaft 13. Has been issued.

[0011]

However, since the hydraulic circuit of the conventional concrete pump is constructed as shown in FIG. 4, the pressure of the accumulator 26 fluctuates even if the operation of the secondary oil pump 23 is stopped. Since it acts on the moving cylinders 14 and 15 and the pilot lines 28, 30, and 31,
When the main hydraulic piston 9 of the main hydraulic cylinders 7 and 8 is moved back and forth to move the concrete pressure-feeding piston 5 forward and backward, the swing switching valve 27 is automatically switched according to this operation, and the swing cylinders 14 and 15 are moved. There is a problem that the rocking tube moves due to the movement of.

Therefore, the present invention is intended to make it possible to immediately stop the movement of the rocking pipe even when the concrete pumping piston is moved forward and backward when the operation of the secondary oil pump is stopped. is there.

[0013]

In order to solve the above problems, the present invention provides a pressure oil line for supplying pressure oil from an auxiliary oil pump to an oscillating cylinder for oscillating an oscillating tube in a hopper. Is equipped with an accumulator and a swing switching valve in order from the upstream side, while the main oil pump supplies and discharges pressure oil to two main hydraulic cylinders for operating a concrete pressure-feeding cylinder for sucking and discharging concrete in the hopper. A main switching valve is provided in the middle of the line, and a pilot line that applies pilot pressure to both sides of the boost valve through a pilot switching valve that switches at the forward stroke end of the main hydraulic cylinder, and the main switching valve through the boost valve. Pilot line for applying pilot pressure to both sides of the In the hydraulic circuit of the oscillating valve type concrete pump including a branch pilot line, a pressure relief switching valve is provided at a position upstream of the accumulator of the pressure oil line to the oscillation cylinder, and the pressure relief switching valve and the above An auxiliary pilot line is connected to one of the branch pilot lines, and a shuttle valve is incorporated in the connecting portion of the auxiliary pilot line.

[0014]

[Operation] When the inside of the concrete pumping cylinder is cleaned, the pressure relief switching valve is operated to direct the pressure of the accumulator to the pressure relief line, and the pressure is branched through the auxiliary pilot line and the shuttle valve. By acting on the pilot line, the switching position of the rocking switching valve is locked to one side, so that the motion of the rocking cylinder can be stopped. Therefore, it is possible to carry out the cleaning work while operating the concrete pressure-feeding cylinder while the rocking pipe is flipped up.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention. In a hydraulic circuit of an oscillating valve type concrete pump having a structure similar to that shown in FIG. 4, a pressure is applied to a position upstream of an accumulator 26 in a pressure oil line 24. A relief switching valve 38 is provided, and the accumulator 26 is provided through the pressure relief switching valve 38.
37, 39 are provided between the upstream side and the downstream side of the rocking cylinder 14, by switching the pressure relief switching valve 38.
15 of the auxiliary pilot line 40 is connected to the midway of one pilot line 30a that allows the pressure to be released and the pilot switching pressure is applied to the swing switching valve 27, and the shuttle valve 36 is connected to the connection portion. Assembled,
Moreover, when the other end of the auxiliary pilot line 40 and the line 37 led from the upstream position of the accumulator 26 of the pressure oil line 24 are connected via the pressure relief switching valve 38 and the auxiliary oil pump 23 is stopped. , The pressure relief switching valve 38 is switched from the port a to the port b in the figure, so that the pressure by the accumulator 26 is changed to the auxiliary pilot line 4
0, shuttle valve 36, pilot line 3 for switching operation
0a to actuate one switching operation portion of the swing switching valve 27 to pressurize the port in one direction so that the port can be locked, and the pressure acting on the swing cylinders 14 and 15 is supplied to the line 39 and the pressure release. It returns to the tank via the switching valve 38. During operation of the auxiliary oil pump 23, the pressure of the accumulator 26 passes from the line 37 through the port a of the pressure relief switching valve 38 and is joined by the line 39 to the pressure oil line 24 on the upstream side of the swing switching valve 27. I am doing it. Four
1 is a pilot check valve, 42 is a piston withdrawal valve, 4
Reference numeral 3 indicates a relief valve.

When the concrete pressure-feeding cylinders 3 and 4 are cleaned after the concrete pressure-feeding work is finished, first, as shown in FIG. 6, the rocking pipe 11 is flipped up by a separate means. In addition, the auxiliary oil pump 23 is stopped so that the pressure relief switching valve 38 shown in FIG. 1 is switched from the port a to the port b, and the cleaning nozzle 34 is brought into the hopper 1 to transfer the cleaning water to the concrete pressure-feeding cylinder 3. Concrete injection cylinders 3 and 4 are operated while being injected into the inside of the cylinder 4.

That is, after the rocking pipe 11 is flipped up and the pressure relief switching valve 38 is switched to the port b, the main oil pump 1
If only 8 is operated, the main hydraulic cylinder 7,
By alternately advancing and retracting the main hydraulic piston 9 of No. 8, the concrete pumping pistons 5 in the concrete pumping cylinders 3, 4 are alternately advanced and retracted. At this time, the rocking cylinders 14, 15 The pressure of the accumulator 26 acting on the valve is released through the line 39, the pressure of the accumulator 26 is passed from the line 37 through the port b of the pressure relief switching valve 38, and further through the auxiliary pilot line 40. And acts on one switching operation portion of the swing switching valve 27 via the shuttle valve 36, so that the position of the swing switching valve 27 is pressurized and locked. Therefore, the rocking cylinders 14 and 15
Even if the pressure of the accumulator 26 acts from the pressure oil line 24, the expansion / contraction position is held at one stroke end, and the operation is stopped.

For this reason, the operator must move the swing cylinder 14,
It becomes possible to smoothly wash the concrete pressure-feeding cylinders 3 and 4 while observing the internal condition without paying attention to the movement of 15. Further, at this time, since the rocking tube 11 is flipped up, the inside of the hopper 1 can be easily cleaned.

Although the present invention has been described with reference to the case where the concrete pump handles concrete in the above embodiment, the present invention can be similarly applied to the case where the concrete pump handles other high-viscosity fluids, and other deviates from the gist of the present invention. It goes without saying that various changes can be made within the range not covered.

[0021]

As described above, according to the hydraulic circuit of the rocking valve type concrete pump of the present invention, the depressurization line is connected to the position of the accumulator upstream of the pressure oil line to the rocking cylinder to switch the rocking motion. Since the auxiliary pilot line, one end of which is connected to one branch pilot line of the valve, and the pressure release line are connected via the pressure release switching valve, and the shuttle valve is attached to the connecting portion between the pilot lines. , The pressure of the rocking cylinder is released to the line by operating the pressure relief switching valve, and the pressure of the accumulator is further applied to the rocking switching valve via the auxiliary pilot line and the shuttle valve to move the rocking cylinder to one operating position. Since it can be fixed, the concrete pressure-feeding cylinder can be simplified while watching the internal condition with the rocking tube flipped up without worrying about the movement of the rocking cylinder. It is possible to wash the, there is exhibited an excellent effect that.

[Brief description of drawings]

FIG. 1 is a schematic view showing an embodiment of a hydraulic circuit of a swing valve type concrete pump of the present invention.

FIG. 2 is a schematic view showing an example of a swing valve type concrete pump.

3 is a view taken along the line III-III in FIG.

FIG. 4 is a schematic view showing an example of a hydraulic circuit of a conventional rocking valve type concrete pump.

FIG. 5 is a schematic view showing an example of a method for cleaning a concrete pressure-feeding cylinder.

FIG. 6 is a schematic diagram showing another example of a method for cleaning a concrete pressure-feeding cylinder.

[Explanation of symbols]

 1 Hopper 3,4 Concrete pressure-feeding cylinder 7,8 Main hydraulic cylinder 11 Swing pipe 14,15 Swing cylinder 18 Main oil pump 21 Main switching valve 23 Secondary oil pump 24 Pressure oil line 26 Accumulator 27 Swing switching valve 29 Boost Valves 30a, 30b Branch pilot line 32 Pilot switching valve 36 Shuttle valve 37 Line 38 Pressure relief switching valve 40 Auxiliary pilot line

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location F04B 53/16 53/00

Claims (1)

[Claims] 1. A pressure oil line for supplying pressure oil from a sub-oil pump to a rocking cylinder for rocking a rocking pipe in a hopper is provided with an accumulator and a rocking switching valve in order from the upstream side. , A main switching valve is provided in the middle of a line for supplying and discharging pressure oil from a main oil pump to two main hydraulic cylinders for operating a concrete pressure-feeding cylinder for sucking and discharging concrete in a hopper, and the main hydraulic cylinder From the pilot line, a pilot line that applies pilot pressure to both sides of the boost valve through a pilot switching valve that switches at the stroke end on the forward side, a pilot line that applies pilot pressure to both sides of the main switching valve through the boost valve, An oscillating valve type valve that is branched and has a branch pilot line that applies pilot pressure to both sides of the oscillating switching valve. A pressure relief switching valve is provided upstream of the accumulator of the pressure oil line to the rocking cylinder in the hydraulic circuit of the cylinder pump, and an auxiliary pilot line is provided between the pressure relief switching valve and the one branch pilot line. A hydraulic circuit for an oscillating valve type concrete pump, wherein the hydraulic circuit is connected to the auxiliary pilot line and a shuttle valve is incorporated in the connection portion of the auxiliary pilot line.