JP3181086B2 - Piston type slurry pumping system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used for transferring pipes for dredged soil and sludge, transferring pipes for excavating and discharging excavated soil such as tunnels, pumping ready-mixed concrete, and transferring pipes for highly viscous fluids (general slurries). Piston type slurry pumping system to be used.

[0002]

2. Description of the Related Art FIGS. 4 to 7 show examples of the structure of a piston-type pumping device, and FIGS. 8 and 9 show the structure when two piston-type pumping devices are connected in parallel and a time chart during operation. 4 to 7, the pumped material is sucked into the pumping cylinder 1 from the hopper 40 through the suction / discharge valve 8 by the retreat of the pumping piston 2 in the pumping cylinder 1, and then, by the advance of the pumping piston 2, It is pushed out of the discharge port 10 through the suction / discharge valve 8 and is pressure-fed in the discharge pipe.

There are two left and right pumping cylinders 1. The suction stroke and the discharge stroke of the two pumping cylinders are alternately switched left and right by the movement of a swinging pipe 801 moving left and right in the suction and discharge valve 8. By this repetition, the pumped material is continuously pumped. Reference numeral 3 denotes a hydraulic cylinder for moving the two pressure-feeding cylinders 1 back and forth, and both hydraulic cylinders 3 communicate with each other via a closed circuit 7.

In FIG. 8, two pressure feeding devices having the structure described with reference to FIGS. 4 to 7 are connected in parallel, and merge into one at a discharge pipe portion at the end of the discharge port. The two pumping devices are not particularly synchronized, and are moving independently, and the pumping piston and the suction / discharge valve are moving according to a time chart as shown in FIG. In the figure, the phase shift between the first and second units occurs naturally.

[0005]

The above-mentioned prior art has the following problems. When two or more piston-type pumping devices are connected in parallel and pumping is performed by one discharge pipe, during switching of the suction / discharge valves shown in FIG. 9 (example: TG1, TG2, TG3
And the like, a state occurs in which the discharge port 10 and the hopper 40 communicate with each other in the pressure feeding device. At that time, since the other pumping device is in the middle of the pumping process, the inside of the discharge pipe is in a high pressure state, and the pressure (back pressure) causes the pumped material in the discharge pipe to be suction-discharged during the above-described switching. It flows back to the hopper side through the valve (the discharge port communicates with the hopper).

As described above, every time the suction / discharge valve is switched, a considerable amount of the pumped material flows backward from the discharge pipe to the hopper, so that the volumetric efficiency of the pumping device is greatly reduced, the pumping efficiency is reduced, and the energy is reduced. Loss occurs. In order to prevent this, when two or more pumping devices are connected in parallel, it is conceivable to synchronize all the pumping devices. However, in order to perform perfect synchronous operation, the system becomes very complicated. However, it cannot be easily changed (that is, it is necessary to construct a dedicated system from the beginning), and the cost is naturally high.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems in the prior art, and has a simple structure in which the timing of suction of the slurry in two or more piston-type pumping apparatuses can be matched to prevent the backflow of the slurry. It is an object to provide a slurry pumping system.

[0008]

In a slurry pumping system in which a plurality of piston-type pumping devices are installed in parallel,
When the end of the pushing stroke of the pumping piston of each pumping device is detected, and when the pushing strokes of all the pumping devices are finished,
At the same time, the suction and discharge valves of all the pumping devices are switched.

[0009]

When the end of the pushing stroke of the pumping piston of each pumping device is detected, and when the pushing strokes of all the pumping devices are completed, the suction / discharge valves of all the pumping devices are switched at the same time. There is no pressure-feeding device during the pushing-out stroke of the pressure-feeding piston, so that the pressure in the discharge pipe is also low, and backflow from the discharge pipe to the hopper due to back pressure does not occur.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. In the drawing, reference numerals 1 and 101 denote a pressure feeding cylinder, 2 and 102 denote a pressure feeding piston reciprocating in the pressure feeding cylinder, 3
And 103 are hydraulic cylinders for driving the pumping pistons 2 and 102, 4 and 104 are piston rods connecting the pumping pistons 2 and 102 and the hydraulic pistons 5 and 105,
Reference numerals 6 and 106 denote piston detectors that output an electric signal when the hydraulic pistons 5 and 105 reach the stroke end of the hydraulic cylinder, 7 denotes a closed circuit between the hydraulic cylinders 3 and 103, 8 denotes a suction / discharge valve, and 801 denotes suction. The swing pipe of the discharge valve, 9 is a suction / discharge valve switching cylinder for driving the swing pipe 801 of the suction / discharge valve, 10 is the discharge port of the pumping device, and 11 controls the flow of hydraulic oil to the hydraulic cylinders 3 and 103. Hydraulic switching valves 111 and 112 are solenoids of the hydraulic switching valve 11, 12 is a hydraulic switching valve for controlling the flow of pressure oil to the suction / discharge valve switching cylinder 9, and 121 and 122 are hydraulic switching valves 1
2 is a solenoid, 20 is a first OR circuit for ORing output signals of the piston detectors 6 and 106, 21 is a latch for holding the output of the first OR circuit 20, and 22 is 1
Of the output signals of the first and second latches 21 and 521
AND circuit for taking D, 506 and 606 are second piston detectors corresponding to the first piston detectors 6 and 106, 23 is a control circuit for controlling the first hydraulic switching valve 12, 520 and 521 are A second piston detector 506,
A logic circuit for taking the OR of the output signal 606, a latch for holding the output, and a control circuit 523 for controlling the second hydraulic switching valve 12 are provided.

In FIG. 1, the pumped material stored in the hopper passes through the suction / discharge valve 8 by the retraction of the pumping piston 2 (or 102) in the pumping cylinder 1 (or 101). 101), and then pushed out from the discharge port 10 to the discharge pipe through the suction / discharge valve 8 (in the oscillating pipe 801) by the advance of the pressure feeding piston 2 (or 102). Pumping piston 2 (or 10
2) is completed and the pumping piston 2 (or 10
When 2) reaches the top dead center, the piston detector 6 (or 10)
6) An electric signal is transmitted.

The first latch 21 and the second latch 5
The output signal of the unit 21 is ANDed by the logic circuit 22, and when the output signal triggers the control circuits 23 and 523 that switch the suction and discharge valves of the first and second units, the hydraulic pressure of the first and second units is switched. Valve 12 is energized and 1
The intake and discharge valves 8 of the unit and the unit 2 are switched. The above operation will be described with reference to FIG. 3. For example, when the push-out stroke of the left pressure feeding piston 102 of the first unit is completed and the piston reaches the top dead center, a signal is transmitted from the piston detector 106 (B).
The output is held by the latch 21 (D).
(After that, the first machine stops when the left pumping piston 102 reaches the top dead center.) Next, when the pushing process of the right pumping piston 106 of the second machine ends and the top dead center is reached. , A signal is transmitted (F) from the piston detector 506, and its output is held by the latch 521 (I). Here, since two input signals of the AND circuit 22 are (D, I) input, an output signal is output from the AND circuit 22 (E), and the suction / discharge valve control circuits 23 and 523 of the two pumping devices. Is transmitted as a trigger to
The solenoids 122 and 521 of the hydraulic switching valve 12 for controlling the switching cylinder 9 for switching the suction and discharge valves 8 of the two pumping devices are simultaneously energized, and the swing pipes 80 of the two pumping devices are simultaneously energized.
1 are switched simultaneously.

In the above embodiment, the case where the number of the pumping devices is two is shown. However, the number of the pumping devices may be any number as long as it is two or more. , The number of inputs to the AND circuit 22 may be increased. In the above embodiment, the piston detectors 6, 10
Although the example in which the output signals 6, 506, and 606 are processed by hardware has been described, it is needless to say that the output signals are processed by software (using a programmable controller, a microcomputer, or the like), and the time chart shown in FIG. After all of the pumping pistons have reached the top dead center, an output is produced so as to switch the suction and discharge valves of all the pumping devices at the same time).

In the above embodiment, the piston detector is described as being installed independently. However, in order to control the basic operation of the pumping device, the top dead center position of the pumping pistons 2, 102 is controlled. In a device that electrically detects, the signal may be used, and there is no need to newly install a piston detector.

[0015]

The piston type slurry pumping system according to the present invention is a pumping system in which a plurality of piston type slurry pumping devices are connected in parallel, a detector for detecting the end of the pushing stroke of the pumping piston of each pumping device, When the output signals of the detectors of the plurality of pumping devices are all provided, the means for simultaneously switching the suction and discharge valves of all the pumping devices has the following effects. 1. Even if a plurality of pumping devices are connected in parallel, there is no backflow of the pumped material at the time of switching the suction and discharge valves, and high volume efficiency can be secured. 2. Since high volumetric efficiency can be realized, the overall pumping efficiency can be increased and energy loss can be reduced. 3. The system can be realized only by detecting the arrival at the top dead center of the pressure-feeding piston, and can be configured extremely simply and inexpensively. 4. According to the above three items, it can be easily mounted on existing devices.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a piston type slurry pumping apparatus for carrying out the present invention.

FIG. 2 is an electric control block diagram according to the embodiment of the present invention (in the case of two units connected in parallel).

FIG. 3 is a time chart at the time of operation in the embodiment of the present invention (in the case of two units connected in parallel).

FIG. 4 is a side view of a conventional piston type slurry pumping device.

FIG. 5 is a plan view of FIG. 4;

FIG. 6 is an operation diagram of a suction / discharge valve during discharge of a left cylinder.

FIG. 7 is an operation diagram of a suction / discharge valve during discharge of a right cylinder.

FIG. 8 is a plan view of a conventional piston type slurry pumping system.

FIG. 9 is a time chart at the time of operation of the piston type slurry pumping system shown in FIG. 8;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pumping cylinder 2 Pumping piston 5 Hydraulic piston 6 Piston detector 8 Suction / discharge valve 9 Suction / discharge valve switching cylinder 10 Discharge port 12 Hydraulic switching valve

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-61-252876 (JP, A) JP-A-62-101073 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F04B 15/02 E02F 7/10

Claims (1)

(57) [Claims] In a pumping system in which a plurality of piston type slurry pumping devices are connected in parallel, a detector for detecting the end of the pushing stroke of a pumping piston of each pumping device;
Means for simultaneously switching the suction and discharge valves of all the pumping devices when all the output signals of the detectors of the plurality of pumping devices are complete, the piston type slurry pumping system.