JPS6220710Y2 - - Google Patents

Description

[Detailed description of the invention] This invention leads hydraulic oil from a hydraulic pump driven by an engine to a concrete pump, and sequentially controls the driving of the concrete pump and the engine rotation speed without making any mistakes. The present invention relates to a control device for a concrete pump drive device that enables the following. Generally, when driving a concrete pump, first, a hydraulic pump is driven by driving an engine, and hydraulic oil discharged from the hydraulic pump is guided to the concrete pump to drive the concrete pump.

The concrete pump is used to pump concrete with poor fluidity to a high place or a distant place through a transfer pipe, and therefore a large load is applied to the engine. Therefore, for example, if the drive of the concrete pump is temporarily stopped during concrete pumping and then started again, a large load will be applied at the same time as the engine is being driven, so it is necessary to keep the pump running even when the engine speed is increased. , the problem occurs that the engine stops.

In order to solve the above problem, this invention is a hydraulic drive for a concrete pump in which when the concrete pump drive switch is connected, the engine speed is automatically increased first and then the concrete pump is driven. The present invention provides a control device for an apparatus, and examples thereof will be described below with reference to the drawings.

1 is an engine, 2 is a power extraction device, 3 is a hydraulic pump driven by the power extracted from the power extraction device 2, and 4 is mainly a driving hydraulic cylinder 5, a pump cylinder 6, a valve 7, a hopper 8, and a discharge pipe. 9 is a concrete pump, and 10 is a pump control valve that rotates the concrete pump 4 in forward and reverse directions.The control valve 10 and the hydraulic pump 3 are connected through a discharge pipe 11, and the control valve 10 and the oil tank 12 are connected through a discharge pipe 11. They are connected through an oil drain pipe 13, and when the control valve 10 is in the neutral position, the hydraulic oil from the hydraulic pump 3 is returned to the oil tank 12 through the discharge pipe 11, the control valve 10, and the oil drain pipe 13. ing.

Reference numeral 14 designates a directional switching valve that guides hydraulic oil from the hydraulic pump 3 to the tip and base of the drive hydraulic cylinder 5 and drives the concrete pump 4;
and the control valve 10 are connected through pipes 15 and 16, and between the directional control valve 14 and the drive hydraulic cylinder 5 through pipes 17 and 18.

19 is a lever that controls the engine speed, 20
2 is a cylinder connected to the lever 19 to control the rotation speed of the engine 1; 21 is an engine rotation speed control valve that guides hydraulic oil from the hydraulic pump 3 to the tip and base of the cylinder 20; and piping is connected between the control valve 21 and the cylinder 20. This was communicated on 22nd and 23rd. 24 is oil drain pipe 1
This branch pipe 24 is a branch pipe that branches from the middle of 3.
is connected to the control valve 21.

Reference numeral 25 denotes a pressure valve provided in the middle of the oil drain pipe 13 to raise the drain oil in the oil drain pipe 13 and the branch pipe 24 to an appropriate pressure, and the structure of the pressure valve 25 is a check valve in the embodiment.

Next, the electric system that controls the pump control valve 10 and the engine speed control valve 21 described above will be explained with reference to FIG. 2. SOL ₁ is a solenoid that operates the engine speed control valve ₂₁ . A circuit with a forward/reverse switch S is connected. SOL ₂ and SOL ₃ are left and right solenoids that operate the pump control valve 10. One solenoid SOL ₂ is connected to a circuit that includes a forward/reverse switch S and a relay switch RS, and the other solenoid SOL ₃ is a forward/reverse switch S and a relay switch RS. A circuit with a reversing switch S and a relay switch RS is connected. For TR, connect forward/reverse switch S.
The timer that operates when TS is the timer TR
CR is a timer switch that operates and becomes "closed" after a predetermined period of time has elapsed.
The relay switch RS operates when
A relay corresponding to RS, 26 is a power supply.

In operation, first, when the engine 1 is driven and the hydraulic pump 3 is driven, the hydraulic oil from the hydraulic pump 3 is not guided to the concrete pump 4, but is passed through the discharge pipe 11, the pump control valve 10, and the oil drain pipe 13. The oil is returned to the oil tank 12. At this time, the pressure of the drained oil in the oil drain pipe 13 is raised to an appropriate pressure by the pressure valve 25 provided in the middle of the drain oil pipe 13. Next, when the forward/reverse switch S is connected to the forward/reverse contact, the solenoid SOL ₁ of the control valve 21 is energized, so the control valve 21 is switched to the right position, and the drained oil in the oil drain pipe 13 is thereby drained. Branch pipe 2
4. The flow flows into the base chamber of the cylinder 20 through the control valve 21 and the piping 22, causing the cylinder 20 to extend and actuate and actuating the lever 19 to start the engine 1.
Increase the rotation speed and hold it at the high speed rotation position. On the other hand, the timer is activated by operating the forward/reverse switch S.
Since TR will also be activated, this timer TR
Timer switch TS will be activated after a predetermined time has elapsed after activation.
becomes “connected” and relay CR is activated. When relay CR is activated, relay switch RS is “connected”.
Therefore, the solenoid SOL ₂ is energized and the pump control valve 10 is switched to the right position. When the control valve 10 is switched, the hydraulic oil discharged from the hydraulic pump 3 flows through the discharge pipe 11 and the control valve 1.
0, flows into the front chamber of the drive hydraulic cylinder 5 through the pipe 16, the directional control valve 14 and the pipe 18, thereby actuating the concrete pump 4 and pumping the hopper 8.
The concrete inside is sucked into the pump cylinder 6. When the suction stroke is completed, directional valve 1 is automatically
4 is switched, the concrete sucked into the pump cylinder 6 is pumped to the discharge pipe 9. As described above, by switching the directional control valve 14, the concrete in the hopper 6 is transferred to the discharge pipe 9.
It will be pumped to

When stopping the operation of the concrete pump 4 midway, by turning off the forward/reverse switch S described above, energization to the solenoid SOL ₁ and the solenoid SOL ₂ will be cut off.
is switched to the neutral position, cutting off the supply of hydraulic oil to the concrete pump 4 and stopping the concrete pump 4. On the other hand, since the control valve 21 is switched to the left position, this causes the exhaust pressure oil in the discharge pipe 13 to flow into the front chamber of the cylinder 20 through the branch pipe 24, the control valve 21, and the piping, and maintains the high-speed rotation position. Activate the lever 19 that has been rotated to switch to and hold the low speed rotation position.

Incidentally, when the concrete pump 4 is to be reversed, the switch S for forward and reverse rotation is connected to the contact for reverse rotation. Then, the solenoid SOL ₁ of the control valve 21 is energized, so the control valve 21 is switched to the right position, whereby the drain pressure oil in the oil drain pipe 13 is discharged to the branch pipe 2.
4. The flow flows into the base chamber of the cylinder 20 through the control valve 21 and the piping 22, causing the cylinder 20 to extend and actuate and actuating the lever 19 to start the engine 1.
Increase the rotation speed and hold it at the high speed rotation position. On the other hand, the timer is activated by operating the forward/reverse switch S.
Since TR will also be activated, this timer
The timer switch is activated after a predetermined period of time has passed after TR activation.
TS becomes "connected" and relay CR is activated. When the relay CR operates, the relay switch RS becomes "closed", so that the solenoid SOL ₃ is energized and the pump control valve 10 is switched to the left position. When the control valve 10 is switched, the hydraulic pump 3
The hydraulic oil discharged from the discharge pipe 11, the control valve 10,
It flows into the front chamber of the drive hydraulic cylinder 5 through the pipe 15, the directional control valve 14, and the pipe 18, thereby operating the concrete pump 4, and sucking the concrete in the discharge pipe 9 into the pump cylinder 6.

When the suction stroke is completed, the directional control valve 14 will be automatically switched, so the pump cylinder 6
The concrete sucked into the hopper is forced into the hopper 8. As described above, the concrete in the discharge pipe 9 is forced to be fed to the hopper 8 by switching the directional control valve 14, and the hopper 8 is sequentially operated.

As described above, the present invention first controls the engine speed control valve to increase the engine speed, and while keeping the engine speed at high speed, controls the pump control valve to guide hydraulic oil to the concrete pump, and then starts the concrete pump. By making it possible to drive the concrete pump, even if the engine is temporarily stopped while a large load is being applied to the concrete pump, and then the concrete pump is driven again, the engine speed is first increased to the specified speed, and then the concrete pump is turned off. Since the pump is driven, the engine does not stop when driving the concrete pump, and when the concrete pump is stopped, the lever that controls the engine speed is automatically activated, allowing the engine to rotate at high speed. Since the engine speed can be switched to a lower speed, engine power can be used more efficiently.

[Brief explanation of the drawing]

Figure 1 is a hydraulic operation diagram of the concrete pump, Figure 2 is an electrical system diagram that controls the hydraulic operation in Figure 1,
It is. In the figure, 1 is an engine, 3 is a hydraulic pump, 4 is a concrete pump, 10 is a pump control valve, 19 is a lever, 20 is a cylinder, 21 is an engine speed control valve, SOL ₁ and SOL ₂ are solenoids,
S is a switch and TR is a timer.

Claims (1)

[Scope of utility model registration request] The hydraulic pump driven by the engine is switched by the operation of a solenoid, and when the solenoid is energized, the hydraulic fluid from the hydraulic pump is guided to the concrete pump, and when the solenoid is de-energized, the hydraulic fluid is Switched by a pump control valve that returns hydraulic oil from the pump to the oil tank and a solenoid.
A hydraulic drive device for a concrete pump, comprising at least an engine rotation speed control valve that controls the engine rotation speed by guiding hydraulic oil from a hydraulic pump driven by the engine to a cylinder connected to an engine rotation speed control lever. A circuit that can energize the solenoid of the engine speed control valve when a switch is connected is connected to the solenoid of the engine speed control valve, and a circuit that can energize the solenoid of the engine speed control valve is connected to the solenoid of the pump control valve. A control device for a hydraulic drive device for a concrete pump, in which a timer is activated when the timer is activated, and a circuit is connected that can energize a solenoid of a pump control valve after a predetermined period of time has elapsed after the timer activation.