JP3477560B2 - Control circuit of oscillating cylinder in oscillating valve concrete pump - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a swinging device stored in a hopper.
Swing the pipe left and right to switch between suction and discharge
Oscillating valve type concrete pump
The control circuit of the oscillating cylinder that oscillates
You. [0002] 2. Description of the Related Art Among concrete pumps, a swing valve type is known.
The concrete pump, as shown in Figs.
Two suction and discharge ports 2 are installed side by side at the bottom
The outside of the hopper 1 is connected to the two suction and discharge ports 2 respectively.
The two concrete cylinders 3 and 4 that communicate with each other
Installed in parallel with each concrete cylinder 3 and 4
The concrete-feeding piston 5 housed in the
Not shown connected to concrete pressure feed cylinders 3 and 4
To the main piston in the two main hydraulic cylinders via rod 6
And the two main hydraulic cylinders are alternately connected
Piston for concrete pumping by moving forward and backward
5 is alternately moved forward and backward. Also, hot
In the par 1, an oscillating tube 7 bent into an S-shape is stored,
A seal ring 8 is attached to one end of the swing tube 7 to
If two inlets and outlets 2 can be matched alternately,
Then, the other end of the swing tube 7 is inserted through the back of the hopper to be transported.
Connected to the sending pipe 9 and fixed in the middle of the swinging pipe 7
The connecting shaft 10 penetrates through the front side wall of the hopper 1 and projects outside.
And attach the operation lever 11 to the outside of the hopper 1
Two swinging cylinders 12 and 13 and operating lever 11
And the operating levers are operated by the swinging cylinders 12 and 13.
The swing tube 7 is connected to the connecting shaft 1 by tilting the swinging tube 11 left and right.
So that it can swing right and left around 0
It is. [0003] Therefore, concrete in the hopper 1
For pumping, two oscillating cylinders 12 or 13
The swing tube 7 is swung to the left and right, and two
Main hydraulic pressure is applied to the piston 5 in the cleat pressure feeding cylinders 3 and 4.
When the cylinder is moved forward and backward alternately by the cylinder,
Concrete is condensed from one of the inlet and outlet 2
When sucked into the reed pressure feed cylinder 3 or 4,
Of the concrete pumping cylinder 4 or 3
Concrete that is connected and sucked inside is a piston
5 is pushed by the advance of 5 and passes through the swinging pipe 7 to the transport pipe 9.
Is sent and discharged.
Swing in accordance with the forward and backward movement of the piston 5 in the
The swing tube 7 is swung right and left by the moving cylinders 12 and 13.
So that the concrete can be moved to the rocking tube 7
The liquid can be continuously discharged through the pipe 9. [0004] However, the swing valve type
In the case of a concrete pump, the swinging pipe 7 is
Since the rocking tube 7 is immersed in the concrete,
When switching between suction and discharge by swinging
Resistance is high. In particular, the properties of concrete in hopper 1
Shape (hardness of slump, size of aggregate, etc.) and length of swing tube 7
The switching resistance changes depending on the size of the switch. In this case,
The control circuit of the swing cylinders 12 and 13 is shown in FIG.
Thus, the pressure oil discharged from the oil pump 14 is
Upstream to the pressure oil line 15 to be supplied to the cylinder 12 or 13
Unload valve 16, accumulator ACC, electromagnetic from side
An electromagnetic switching valve 17 is provided, and the electromagnetic switching valve 17 is turned off.
Supply pressure oil to the oscillating cylinder 12 or 13 instead
To swing the swing tube 7, but unload
Because there is only one valve 16, the properties of concrete
Even if the switching resistance of the oscillating tube 7 changes and increases, the pressure oil
The unload valve 16 is actuated by the pressure of the
Oil is released to the tank 18 without being sent to the electromagnetic switching valve 17
However, even if the switching resistance changes, the setting of the unload valve 16
Until pressure is reached, pressurized oil is sent to the oscillating cylinder 12 or 13.
It is working. A conventional control circuit includes a swing cylinder 12
Or with the rocking tube 7 switched by 13
Even when stopped, it is rocked by accumulator ACC.
The dynamic cylinder 12 or 13 is always in a pressurized state.
The solenoid-operated switching valve 17 is switched
Oscillating syringe by pressure from accumulator ACC
The situation that the switch 12 or 13 is switched occurs.
Cause problems during maintenance. [0006] Therefore, the present invention is to reduce the pressure of the swing cylinder
Switch to a two-stage system and swing
Avoid accumulator pressure on the Linda
Trying to do it. [0007] The present invention solves the above problems.
Pressure oil discharged from the oil pump
Accumulator and electromagnetic disconnect
In a swing valve type concrete pump provided with a valve
Upstream of the accumulator in the swing cylinder control circuit
Of the oscillating tube by the above oscillating cylinder
Operate according to the change in resistance to change the set pressure.
The relief valve for low pressure and the relief valve for high pressure
Provided separately, a line connecting the two relief valves and the tank
On the waySwitching resistor for the swing tube by the swing cylinder
When the resistance is small or largeAbove relief valve for low pressure
Or high pressure relief valveTo supply to the oscillating cylinder
The pressure oil in the pressure oil line to be used for the low pressure relief valve or high pressure
Release to the tank through the relief valvePressure switching
Provide a solenoid valve for use, and to one of the above relief valves
Excludes the flow path of the hydraulic oil line
When operation is stopped, demagnetize and connect the flow path to the tank
To the oscillating cylinder including the accumulator
To release the used pressure to the tank.
A configuration is provided with a dynamic pressure release solenoid valve. [0008] [Function] During operation of the concrete pump, automatic pressure release
The magnetic valve is energized and shuts off the circuit. Rocking syringe
The switching resistance when switching the oscillating tube by
When the switching resistance is small,For pressure switching
solenoid valveTo operate the low pressure relief valve
make low. When the switching resistance is large,Electromagnetic for pressure switching
valveTo operate the high pressure relief valve to increase the set pressure
Can be When not in operation, automatic pressure release
By demagnetizing the solenoid valve, the port is switched to the communication state.
The pressure of the accumulatorAutomatic pressure relief solenoid valve
Can escape to the tank throughThe swing cylinder is turned off
Will not be replaced. [0009] Embodiments of the present invention will be described below with reference to the drawings.
I do. FIG. 1 shows an embodiment of the present invention.
Switching control circuit for oscillating cylinders 12 and 13 shown in FIG.
Similarly, the discharge side of the oil pump 14 and the oscillating cylinder 12,
13 and the unload valve 1
6. Accumulator ACC, electromagnetic switching valve 17 provided
In one configuration, instead of the unload valve 16, a low
The pressure relief valve 19 and the high pressure relief valve 20 are installed separately.
Oscillating pipe 7 by oscillating cylinders 12 and 13 (see FIG. 2)
Above) depending on the magnitude of the switching resistance
19 or the high pressure relief valve 20 is actuated to set the set pressure.
To be able to change
Of the line 21 connecting the valve 19 and 20 with the tank 18
A pressure switching solenoid valve 22 is provided on the way, and the solenoid valve 22 is turned off.
Relief valve 19 for low pressure or relief for high pressure
Switch the safety valve 20. Further, the pressure oil line 23 is
Incorporates an automatic pressure relief solenoid valve 24 having a communication port b
Connected during operation of the concrete pump.
And is held at port a. Now, the operation of the concrete pump is started.
And the automatic pressure release solenoid valve 24 is excited and cut to the port a.
The pressure oil acting on the high pressure relief valve 20 is
To the relief valve 20 side and act only on the relief valve 20 side
And the pressure switching solenoid valve 22 is switched to port a.
Alternatively, the low-pressure relief valve 19 can be operated.
Good. The switching of the electromagnetic switching valve 17 causes the swing
Supply pressure oil to the cylinder 12 or 13 via the pressure oil line 15
Then, the swinging pipe 7 is moved leftward by the swinging cylinders 12 and 13.
Switch to the right. The switching resistance at this time is
It changes depending on the composition of the plate, etc.
The relief valve for low pressure 1
9 operates to release the pressure oil in the pressure oil line 15 to the low-pressure relief.
It escapes to the tank 18 through the valve 19. As a result,
To the oscillating cylinder 12 or 13 through the magnetic switching valve 17
No pressurized oil is supplied, so it is impossible to switch the swing pipe 7
Will not occur. On the other hand, when the switching resistance of the swing tube 7 is large
At first, let the pressure oil in the pressure oil line 15 escape to the tank 18.
To excite the pressure switching solenoid valve 22, the port b
To make the high pressure relief valve 20 operate.
You. If the switching resistance is large in this state, the pressure oil line 15
Of the high pressure relief valve 20 by the action of the pressure
Then, the pressure oil in the pressure oil line 15 operates the high pressure relief valve 20.
It will be escaped to the street tank 18. As described above, the pressure of the swing cylinders 12 and 13 is
The power can be switched between high pressure and low pressure in two stages.
Even if the switching resistance changes to high or low depending on the compounding and piping length, etc.
The pressure in the pressure oil line 15 can be released. Next, the operation of the concrete pump is stopped.
ThenFIG.In the conventional method shown in
Pressure remains on the oscillating cylinder 12 or 13
However, in the present invention, the self-demagnetization caused by the
Since there is a dynamic pressure release solenoid valve 24, the solenoid valve 24
b to act on the high pressure relief valve 20
Pressure oil in pressure oil line 15 is automatically depressurized from line 23
It will be released to the tank 18 through the solenoid valve 24.
You. This makes the oscillating syringe including the accumulator ACC
The pressure acting on das 12 and 13 will be released.
Therefore, even if the electromagnetic switching valve 17 is switched,
Since there is no pressure supply to the cylinders 12 and 13,
The switches 12, 13 are not switched. In the embodiment, the automatic pressure release solenoid valve 24 is
Although the case where it was connected to the high pressure relief valve 20 side was shown,
The same applies when connected to the low pressure relief valve 19 side,
Various other changes may be made without departing from the spirit of the present invention.
Of course, it can be added. [0018] As described above, the oscillating cylinder of the present invention
According to the control circuit, the pressure oil discharged from the oil pump is oscillated.
The accumulator and the power supply line
For a swing valve type concrete pump equipped with a magnetic switching valve
Of the accumulator of the control circuit of the oscillating cylinder
Oscillating pipe by the above-mentioned oscillating cylinder in the upstream hydraulic oil line
Activated according to the change of the switching resistance of
Low pressure relief valve and high pressure relief to change
And a relief valve is provided separately to connect the two relief valves to the tank.
In the middle of the lineCutting of oscillating tube by the above oscillating cylinder
When the replacement resistance is small or largeLily for low pressure above
Pressure valve or high pressure relief valveSwitching the swing cylinder
Pressure oil in the pressure oil line to be supplied to the low-pressure relief valve or
Release to the tank through high pressure relief valvePressure
A force switching solenoid valve is provided, and either one of the above
The hydraulic pressure line to the valve
When the operation is stopped and the operation is stopped, degaussing is performed and the flow path is connected to the tank.
Oscillating syringe containing the accumulator
So that the pressure acting on the tank is released to the tank
Automatic pressure relief solenoid valve
When the switching resistance of the rocking tube changes due to the mixing of cleats, etc.
However, when the switching resistance is low, a low pressure relief valve
To release the pressurized oil in the pressurized oil line to the tank.
If the change resistance is high, the high pressure relief valve
The oscillating cylinder is set so that the oil in the oil line escapes to the tank.
Switch the pressure of the heater to two stages, high pressure and low pressure.
And the residual pressure of the accumulator when not operating
Can be released by the automatic pressure release solenoid valve that is in communication.
Even if the electromagnetic switching valve is switched during maintenance,
Excellent effect that the swing cylinder does not operate
Can be played.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram showing an example of a control circuit according to the present invention. FIG. 2 is a sectional view showing a part of a swing valve type concrete pump. FIG. 3 is a view showing a portion of the concrete pump of FIG. 2 for rocking a rocking tube. FIG. 4 is a schematic diagram showing a control circuit of a conventional swing cylinder. [Description of Signs] 12, 13 Oscillating cylinder 14 Oil pump 15 Pressure oil line 17 Electromagnetic switching valve 18 Tank 19 Low pressure relief valve 20 High pressure relief valve 21 Line 22 Pressure switching electromagnetic valve 23 Line 24 Automatic pressure release electromagnetic Valve ACC accumulator

Claims (1)

(57) [Claim 1] A swing valve type concrete pump in which an accumulator and an electromagnetic switching valve are provided in a pressure oil line for supplying pressure oil discharged from an oil pump to a swing cylinder. A low-pressure relief valve that operates in accordance with a change in the switching resistance of the oscillating tube by the oscillating cylinder to a set oil pressure in a pressure oil line on the upstream side of the accumulator of the oscillating cylinder control circuit. And a high-pressure relief valve are separately provided, and the switching cylinder for switching the oscillating pipe by the oscillating cylinder is provided in the middle of the line connecting the two relief valves and the tank.
When the drag is small or large, the above low pressure relief valve or high pressure relief valve is switched and supplied to the oscillating cylinder.
The pressure oil in the pressure oil line to be used for the low pressure relief valve or high pressure
A pressure switching solenoid valve is provided to release to the tank through the relief valve, and the operating pressure oil line to one of the above relief valves is energized during operation, shuts off the flow path, and is demagnetized when operation is stopped And an automatic pressure release solenoid valve for releasing the pressure acting on the oscillating cylinder including the accumulator to the tank by connecting the flow path to the tank. The control circuit of the swing cylinder in the swing valve type concrete pump.