JPH0723713B2 - Fluid pressure pump control method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a control method of a hydraulic piston type fluid pressure pump suitable for transporting fluid such as excavated earth and sand, muddy water, concrete, sludge, silt, and the like. The present invention relates to a control method when used as a relay pump for pumping a fluid supplied from the rear to the front.

<< Prior Art >> A hydraulic piston type fluid pressure pump includes a pair of cylinders for alternately sucking and discharging a transport fluid supplied into a hopper and a hydraulic drive system for the cylinders, and a complicated valve mechanism such as a valve. It is durable and suitable for transportation of excavated soil, muddy water, concrete, sludge, silt, etc. Therefore, for example, it is often used for transportation of excavated earth and sand in shielded mines, relay transportation, and the like.

<< Problems to be solved by the invention >> By the way, for example, when the fluid pressure pump is used as a relay point for transportation of excavated earth and sand in a shield mine or long distance transportation, the amount of excavated earth and sand transported is not always constant. However, since it varies considerably depending on the soil quality and the excavation work situation, it is necessary to constantly monitor the operation situation and respond to the variations in the excavated sediment supplied to the fluid pressure pump.

In the past, monitoring was done manually and the opening of the flow control valve was changed every time the amount of sediment supply fluctuated.
When the shield pit was very long, many pumps were installed as relay points, which required a lot of man-made.

The present invention has been made in view of the above problems, and a hydraulic piston type fluid pressure pump of this type is used as a relay pump, that is, a pump for pumping forward a fluid as a fluctuation amount supplied from the rear. In this case, it is an object of the present invention to provide a method for controlling a fluid pressure pump that can automatically save the discharge amount of the fluid in accordance with the supply amount of the fluid, thereby eliminating the need for monitoring and saving labor.

<< Means for Solving Problems >> In order to achieve the above object, the present invention includes a pair of cylinders for sucking and discharging the transport fluid supplied into the hopper, and a hydraulic drive system for the cylinders. A control method when a fluid pressure pump is used as a relay pump for pressure-forwarding a fluid sent from the rear, the liquid level of the fluid supplied into the hopper is detected, and the detection is performed. Compare the liquid level with a preset level,
The comparative value is output to control the opening of the proportional control valve in the hydraulic drive system, which is set to the opening corresponding to the output, and the hydraulic pressure is adjusted according to the valve opening of the proportional control valve. By variably setting the operating cycle of the cylinder, the fluid is pumped while the liquid level in the hopper is made constant.

Here, the relay pump refers to a pump having a function of transporting a fluid as a fluctuation amount that cannot be controlled by the fluid transportation line from front to back, for example, excavating earth and sand as a fluctuation amount generated in an excavation process. Examples of the pump include a pump used as a relay point when transporting a fluid over a long distance, and the like.

Further, the front side and the rear side refer to the front side and the rear side in the fluid transport direction.

<< Operation >> According to the present invention, the operation cycle of the hydraulic cylinder is variably set according to the detected liquid level, whereby the liquid level in the hopper is kept substantially constant.

<< Embodiment >> An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a partial schematic side view showing the overall structure of a fluid pressure pump according to this embodiment, FIG. 2 is a perspective view showing the principle structure of the fluid pressure pump, and FIG. It is a time chart shown.

In the figure, this fluid pressure pump includes a trolley 3 which can travel on a traveling rail 1 laid in a shield mine via wheels 2, a hopper 4 provided in a front portion of the trolley 3, and a hopper 4
A pair of cylinders 5 that are arranged so as to communicate with the lower part of the rear end,
A trunk 6 that is swingably arranged in the hopper 4 and that alternately opens and closes the opening of the cylinder 5, a switching cylinder 7 that alternately drives the trunk 6 to open and close, and a piston 8 that is inserted into the cylinder 5. The cylinder 5 is provided with a hydraulic cylinder 9 for driving a piston, which is integrated with the rear part of the cylinder 5, a discharge pipe 10 continuous to the rear part of the trunk 6, and a supply pipe 11 connected to the hopper 4.

The fluidized excavated earth and sand put into the hopper 4 through the supply pipe 11 is sucked into the cylinder 5 by the backward movement of one piston 8, and when the piston 5 reaches the final position, a limit switch (not shown) detects this. Then, the switching cylinder 7 operates. This allows the trunk 6
Is switched and connected to the front part of the cylinder 5 filled with earth and sand.

The piston 8 that has completed the suction moves forward and pumps earth and sand to the discharge pipe side 10 through the trunk 6.

This movement is an alternating movement between the pistons 8, and by adjusting the hydraulic drive circuit of the hydraulic oil for the hydraulic cylinder 9, the operating cycle of each piston 8 can be set and the discharge amount can be adjusted.

In the present invention, the above adjustment is automatically controlled according to the amount of excavated earth and sand supplied from the rear into the hopper 4.

That is, an ultrasonic wave transmitter / receiver 12 for detecting the liquid level of the earth and sand in the hopper 4 is arranged above the hopper 4,
Further, from the hydraulic drive circuit via the rubber hose 13,
An electromagnetic flow proportional control valve 14 is provided in a branched manner.

Further, an automatic operation panel 15 is arranged near the trolley 3.

Inside the automatic operation panel 15, an ultrasonic oscillator 16 for transmitting ultrasonic waves to the ultrasonic wave transmitter / receiver 12 and a signal of a reflected wave received by the ultrasonic wave transmitter / receiver 12 are received, and a transmission / reception time difference is calculated. The time difference measuring unit 17, the standard time difference signal preset by the setting unit 18, and the actual measurement time calculated by the time difference measuring unit 17 are compared, and the comparison unit 19 and the comparison unit 19, which calculate the difference, are set. A display unit 20 for displaying or recording the value of the unit 18 is arranged.

Then, the flow rate proportional control valve 14 has a valve opening degree according to the output from the comparison unit 19, and as shown in FIG.
When T1 becomes longer than the set time T0, that is, when the liquid level becomes lower than the preset standard liquid level, the proportional control valve 14 turns to the closing side, with an output (-) corresponding to the difference.

As a result, the operation cycle of the piston 8 is lengthened and the discharge amount is reduced.

Further, when the measured time T2 becomes shorter than the set time T0, that is, when the liquid level rises above the preset standard liquid level, the output corresponding to the difference becomes (+), and the proportional control valve 14 is placed on the open side. However, the operation cycle of the piston 8 becomes short and the discharge amount becomes large.

As described above, this fluid pressure pump automatically increases / decreases the forward discharge amount in accordance with the increase / decrease in the amount of earth and sand supplied from the rear into the hopper 4, thereby preventing overflow in the hopper 4 and idle operation. Of.

In addition, in the embodiment, the case where the present invention is applied to the transportation of the excavated earth and sand in the shield pit is shown, but the present invention is not limited to this, and when used as a so-called relay pump, concrete, other It can be generally applied to transportation of fluids having high viscosity and in which particles are mixed inhomogeneously in the fluid.

Needless to say, as the sensor, not only the ultrasonic wave transmitter / receiver but also another known liquid level sensor can be used.

<Effect> As described in detail above, the control method of the fluid pressure pump of the present invention detects the liquid level of the fluid supplied into the hopper, and variably sets the operation cycle of the hydraulic cylinder based on the detection result. . Therefore, even when the amount of excavated soil as a fluid supplied from the rear varies depending on the working situation, such as when pumping excavated soil, the liquid level in the hopper can be kept constant. It is possible to save labor in the fluid pressure feeding work by eliminating the need to control the supply / pressure feeding amount of the fluid to the fluid pressure feeding pump.

[Brief description of drawings]

FIG. 1 is a partial schematic side view showing the overall structure of the fluid pressure pump of the present invention, FIG. 2 is a perspective view showing the principle structure of the fluid pressure pump, and FIG. 3 is a time chart showing the action during control. It is a chart. 4 …… Hopper 5 …… Cylinder 8 …… Piston 9 …… Hydraulic cylinder 10 …… Discharge pipe 11 …… Supply pipe 12 …… Ultrasonic transducer (sensor) 14 …… Flow rate proportional control valve 17 …… Time difference measurement Section 18 …… Setting section 19 …… Comparison section

Claims (1)

[Claims] 1. A fluid pressure pump having a pair of cylinders for sucking and discharging a transport fluid supplied into a hopper, and a hydraulic drive system for the cylinders, wherein a fluid sent from the rear is forwardly pumped. A control method for use as a relay pump in order to detect the liquid level of the fluid supplied into the hopper, compare the detected liquid level with a preset level, and compare Is output to control the opening of a proportional control valve in the hydraulic drive system, which is set to an opening according to the output, and the hydraulic cylinder operates according to the valve opening of the proportional control valve. A method of controlling a fluid pressure pump, wherein a fluid is pressure-fed while keeping a liquid level in the hopper constant by variably setting a cycle.