JPS6371587A - Control system for fluid pressure feed pump - Google Patents

Abstract

PURPOSE:To save manpower for operating a hydraulic piston type fluid pressure feed pump, by controlling the delivery automatically corresponding to the fluid supply. CONSTITUTION:When a supersonic transmitter/receiver 12 arranged on a hopper 4 detects the level of fluid in the hopper 4, various machineries When the liquid level drops below a preset referential level, the output is reduced corresponding to the difference, thereby a proportional control valve 14 rotates to the closing side so as to lengthen the operating period of a pressure feed piston thus reducing the delivery. When the detected liquid level is higher than the referential level, the delivery is increased. Since the delivery of a fluid transportation pump can he increased/decreased automatically according to the increase/ decrease of fluid supply, overflow of the hopper 4 or idling of pump can be prevented thereby manual monitoring is not required resulting in saving of manpower.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a hydraulic piston-type fluid pressure pump suitable for transporting concrete, sludge, silt, etc., and in particular automatically adjusts the discharge amount according to the supply amount. Regarding the control method.

(Prior Art) A hydraulic piston-type fluid pressure pump is equipped with a pair of cylinders that alternately suck in and discharge the transport fluid supplied into a hopper, and a hydraulic drive system for the cylinders, and has a complicated valve mechanism such as a valve. It is durable and suitable for transporting concrete, sludge, silt, etc. For this reason, they are often used, for example, for transporting excavated earth and sand in shield mines, and for relay transport.

(Problems to be Solved by the Invention) By the way, when this fluid pressure pump is used for transporting or relaying excavated soil in a shield pit, the amount of excavated soil transported is not necessarily constant and depends on soil quality and excavation work conditions. Since the operating conditions vary considerably, the operating status must be constantly monitored and changes must be dealt with.

In the past, monitoring was done manually and the opening of the flow rate control valve was changed depending on the fluctuation, but in cases where the length of the shield pit is quite long, multiple pumps are installed as relay points. Therefore, many artificial materials were necessary.

The present invention has been made in view of the above problems, and it eliminates the need for manual monitoring and automatically controls the discharge amount according to the supply amount in this type of hydraulic screw type fluid pressure pump. The purpose is to save labor by doing so.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a fluid pumping system comprising a pair of cylinders for suctioning and discharging transport fluid supplied into a hopper, and a hydraulic drive system for the cylinders. In the pump, a liquid level sensor disposed on the upper surface of the hopper, a comparison means for comparing an output value of the sensor with a set value corresponding to a standard liquid level in the hopper and outputting a difference output, and the hydraulic drive system and a proportional control valve that is set to an opening degree according to the output of the comparison means, and the operating cycle of the hydraulic cylinder is variably set according to the valve opening degree of the proportional control valve. It is characterized by

(Function) The operating cycle of the hydraulic cylinder changes according to the detected value of the liquid level sensor, and the fluid is transported at a discharge amount corresponding to the supply amount.

(Example) Hereinafter, an example of the present invention will be described in detail using the drawings.

Fig. 1 is a partially schematic side view showing the overall structure of the fluid transport pump of the present invention, Fig. 2 is a perspective view showing the principle structure of the fluid transport pump, and Fig. 3 is a timing diagram showing the action during control. It is a chart.

In the figure, this fluid transport pump includes a truck 3 that can run via wheels 2 on a running rail 1 laid in a shield mine, and a hopper 4 provided at the front of the truck 3.
A pair of cylinders 5 arranged in communication with each other at the lower part of the rear end;
a trunk 6 that is swingably arranged in the hopper 4 and alternately opens and closes the opening of the cylinder 5; a switching cylinder 7 that alternately drives the trunk 6 to open and close; a piston 8 inserted into the cylinder 5; A hydraulic cylinder 9 for driving a piston is integrated at the rear of the cylinder 5, a discharge pipe 10 is continuous to the rear of the trunk 6, and a supply pipe 11 is connected to the hopper 4.

The excavated soil in a fluid state is put into the hopper 4 through the supply pipe 11, and is sucked into the cylinder 5 by the backward movement of one piston 8. When the piston 5 reaches its final position, a limit switch (not shown) detects this. Then, the switching cylinder 7 is activated. With this, trunk 6
is switched and connected to the front part of the cylinder 5 filled with earth and sand.

After the suction is completed, the piston 8 moves forward and forces the earth and sand through the trunk 6 to the discharge pipe side 10.

This movement is an alternating movement between the pistons 8, and by adjusting the hydraulic drive circuit for the hydraulic oil to 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 supply amount.

That is, an ultrasonic transducer 12 is arranged above the hopper 4 to detect the liquid level of the earth and sand in the hopper, and
An electromagnetic flow rate proportional control valve 14 is branched from the hydraulic drive circuit via a rubber boss 13.

Furthermore, an automatic driving board 15 is arranged near the trolley 3.

Inside the automatic operation board 15, there is an ultrasonic oscillator 16 that transmits ultrasonic waves to the ultrasonic transducer 12, and an ultrasonic oscillator 16 that receives reflected wave signals received by the ultrasonic transducer 12 and calculates the difference in transmission and reception time. a time difference measurement section 17 that compares the standard time difference signal preset by the setting section 18 with the actual time calculated by the time difference measurement section 17, and a comparison section 19 that calculates the difference.
and comparison section 19. A display section 20 for displaying or recording the value of the setting section 18 is arranged.

Then, the flow rate proportional control valve 14 has a valve opening according to the output from the comparator 19, and as shown in FIG. When the liquid level becomes lower than the surface, the output is (-) corresponding to the difference, and the proportional control valve 14 is rotated to the closing side.

As a result, the operating cycle of the screws 8 to 8 becomes longer and the discharge amount decreases.

In addition, the actual measurement time T2 is shorter than the set time TO.
In other words, when the liquid level rises above the preset standard liquid level,
The output becomes (+) according to the difference, and the proportional control valve 14
is located on the release side, and the operating cycle of the piston 8 is shortened.
The amount of discharge increases.

As described above, this fluid transport pump automatically increases or decreases the discharge amount according to the increase or decrease in the supply amount of earth and sand, thereby preventing overflow in the hopper 4 and dry operation.

In addition, although the present invention is applied to the transportation of excavated soil in a shield mine in the embodiment, the application is not limited to this and is not limited to concrete or other highly viscous fluids that are heterogeneous inside. It can be applied to general transportation of fluids containing particles.

Furthermore, it goes without saying that other known liquid level sensors can be used as the sensor instead of the ultrasonic transducer.

(Effects) As explained in detail in the embodiments above, according to the present invention,
The operating cycle of the hydraulic cylinder changes according to the detected value of the liquid level sensor, and the fluid is transported at a discharge amount that corresponds to the supply amount.

Therefore, according to the present invention, there is no need for manual monitoring, and it is possible to save labor.Especially, when the flow rate of earth and sand fluctuates widely, such as when transporting excavated earth and sand in a shield mine, it is necessary to use a large number of fluid pressure pumps. Suitable for construction sites that require it.

[Brief explanation of the drawing]

Fig. 1 is a partially schematic side view showing the overall structure of the fluid transport pump of the present invention, Fig. 2 is a perspective view showing the principle structure of the fluid transport pump, and Fig. 3 is a timing diagram showing the action during control. Char 1-. 4...Hopper 5...Cylinder 8...Piston 9...Hydraulic cylinder 10...Discharge pipe 11...Supply pipe 1/- 12. ... Ultrasonic transducer (sensor) 14 ... Flow rate proportional control valve 17 ... Time difference measurement section 18 ... Setting section 19 ... Comparison section Patent applicant Obayashi Co., Ltd. Agent Patent attorney - Color Kensuke 1st Masatoshi Matsumoto =
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Claims (1)

[Claims] (1) A fluid pressure pump equipped with a pair of cylinders that suck in and discharge transport fluid supplied into a hopper, and a hydraulic drive system for the cylinders, which includes a liquid level sensor disposed on the top surface of the hopper, and a sensor. a comparison means for comparing the output value with a set value corresponding to the standard liquid level in the hopper and outputting the difference output; 1. A control system for a fluid pressure pump, comprising: a proportional control valve; the operating cycle of the hydraulic cylinder is variably set according to the opening degree of the proportional control valve.