JPH09301535A - Pipeline switching device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To clean a transport pipe rapidly and easily after completing force- feeding of concrete by providing a transport pipe connecting port and a drain pipe connecting port with an equal space to a space between a concrete force- feed pump connecting port and a feed water pump connecting port. SOLUTION: A sliding plate 20 is slided into a cleaning position. In the cleaning position, a feed water pump connecting port 12 is connected to a transport pipe connecting port 21, and a force-feed pump connecting port 11 is connected to a distributing water pipe connecting port 22. A cleaning sponge ball 6 is put in the feed water pump connecting port 12, and a high pressure feed water pump 5 is connected to the feed water pump connecting port 12. Wash water is fed into a transport pipe D from the high pressure feed water pump 5 to move the sponge ball 6 gradually in the transport pipe D toward the tip side so as to discharge residual concrete in the transport pipe D from the tip of the transport pipe D and to clean the inside of the transport pipe D.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe switching device used in a concrete transportation device for pumping fresh concrete through a transportation pipe by a concrete pump.

[0002]

2. Description of the Related Art When a concrete pumping pump (hereinafter, simply referred to as a "pumping pump") is used to pump fresh concrete or the like through a transport pipe, the concrete remaining in the transport pipe after the pumping of the fresh concrete is completed. Must be discharged before curing and the inside of the transport pipe must be washed with clean water.

The conventional discharge and cleaning operation of the residual concrete will be briefly described. First, the pressure pump and the connecting portion of the transport pipe are temporarily disconnected, and concrete adhering to or remaining in the concrete mixer or the pressure pump is discharged from the pressure pump. And then clean the inside of the pump. After that, fresh water for cleaning is stored in the hopper of the pressure pump, and a sponge ball for cleaning the inside of the pipe is put into the transport pipe from the opening of the separated transport pipe to reconnect the pressure pump and the transport pipe. The ball was gradually moved to the tip side in the pipeline by the washing water from the pressure pump, the residual concrete in the pipeline was discharged from the tip of the pipeline, and the inside of the pipeline was cleaned.

[0004]

However, in the above prior art, the pressure pump for supplying fresh water to the transportation pipe must be thoroughly cleaned before cleaning the inside of the transportation pipe. Therefore, there has been a problem that the transportation pipe cannot be cleaned until the cleaning of the pressure pump is completed, and a long time is required for all cleaning.

The present invention has been made in view of such problems, and an object of the present invention is to pump concrete by simultaneously washing the pump and discharging and washing the residual concrete in the concrete transport pipe. It is an object of the present invention to provide a pipe switching device capable of quickly and easily cleaning the transportation pipe after completion of the above.

[0006]

A gist of the invention according to claim 1 is a pipe switching device used in a concrete transportation device for pumping fresh concrete through a transportation pipe by a concrete pumping pump, the base plate and the base plate. A slide plate slidably provided on the base plate, and a movable means for sliding the slide plate. The base plate has a concrete pressure pump connection port connected to the concrete pressure pump and water for cleaning. A water supply pump connection port connected to a water supply pump for supplying water is provided through a space,
On the slide plate, a slide pipe, which communicates with the concrete pressure pump connection port when the slide plate is in the pressure supply position, and a communication pipe connection port which communicates with the water pump connection port when the slide plate is in the cleaning position, A drain pipe connection port communicating with the concrete pressure pump connection port when the cleaning position is reached is provided via an interval equal to the interval between the concrete pressure pump connection port and the water pump connection port. It exists in the characteristic pipe switching device. The gist of the invention according to claim 2 is a pipe switching device used in a concrete transportation device for pumping fresh concrete through a transportation pipe by a concrete pressure pump, comprising a base plate,
A slide plate slidably provided on the base plate, and a movable means for sliding the slide plate. The slide plate has a concrete pressure pump connection port connected to the concrete pressure pump, and a cleaning port. And a water feed pump connection port connected to a water feed pump for feeding water, etc., are provided with a gap, and the slide plate slides on the base plate, and the concrete when the slide plate is in the pressure feed position. A transport pipe connection port that communicates with the pressure pump connection port and communicates with the water pump connection port when in the cleaning position, and a drain pipe connection port that communicates with the concrete pressure pump connection port when in the cleaning position Is the concrete pressure pump connection port and the water pump connection port. Lies in the pipe switching device, characterized in that provided through the intervals equal to the spacing between the bets. The gist of the invention according to claim 3 is that the interval between the concrete pressure pump connection port and the water pump connection port is
The pipe switching device according to claim 1 or 2, wherein the diameter is larger than the inner diameter of the transport pipe connection port. According to a fourth aspect of the present invention, the base plate and the slide plate are provided with valve plates that are in contact with each other. The pipe switching device according to any one of claims 1 to 3, further comprising a pressing unit that presses the valve plate against another valve plate.

The "concrete pump" according to the present invention includes a piston type pump, a squeeze type pump and the like suitable for carrying out the present invention. Further, “sliding” includes the case of moving in the horizontal direction, the vertical direction, and the rotating direction.

"Movable means" means a hydraulic jack,
A hydraulic jack, a pneumatic jack, an electric motor, a sliding mechanism, and the like are suitable for implementing the present invention.

The term "pressing means" includes means for pressing the slide plate against the base plate by hydraulic pressure, means for using a biasing means, and the like suitable for carrying out the present invention.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings.

As shown in FIG. 1, the pipe switching device A according to this embodiment is used for a concrete spraying device B. This concrete spraying device B is connected to a concrete manufacturing plant P which is roughly composed of a slurry unit U, a mixing unit M, a sand hopper H, a cement silo S, etc., a pressure feed pump T for feeding fresh concrete, and this pressure feed pump T. The concrete transporting device E is composed of the transport pipe D and the spray hose F connected to the tip of the transport pipe D via a Y-shaped pipe Y for supplying air.

The concrete production plant P will be described in detail. The slurry unit U is a slurry liquid prepared by mixing a mixing material such as slag and fly ash mixed with concrete, a water reducing agent and the like and kneading water, This is a device for supplying this slurry liquid to the mixing unit M via a slurry liquid supply hose G.

Further, the mixing unit M is the slurry supplied from the slurry unit U.

A predetermined amount of sand and cement introduced from the sand hopper H and the cement silo S together with the liquid are mixed to prepare green concrete, and the green concrete is provided in a hopper portion (not shown) of the pump T. Is a device for supplying to. In such a concrete manufacturing plant P, all the cleaning drainage after cleaning the inside of the concrete manufacturing plant P is discharged from the discharge port of the pressure feed pump T.

On the other hand, a spray nozzle N is attached to the tip of the spray hose F. Further, the Y-shaped pipe Y is connected to the compressor C via an air supply pipe W. This Y
By the high pressure air supplied from the letter Y into the transport pipe D, Y
The concrete pumped to the position of the character pipe Y is air-transported in the transport pipe D and discharged from the spray nozzle N. A pressure management device Z is provided in the middle of the air supply pipe W. A pipe switching device A is connected to the transport pipe D near the pressure pump T.

The pipe switching device A includes a base plate 10 and a base plate 10 as shown in FIGS.
Slide plate 20 slidably provided on the slide plate, and a hydraulic jack 30 for sliding the slide plate 20.
(Movable means) and a pressing device that presses the slide plate 20 against the base plate 10 so that the mortar does not leak from between the base plate 10 and the slide plate 20.

The base plate 10 is a steel plate-like member having a substantially rectangular shape when viewed from the front, and the stand 1 is placed in the vertical plane.
It is bolted to. Anti-vibration rubber 2 for stand 1
It is fixed to the base plate 3 via (not shown in FIG. 2). As shown in FIGS. 5 and 6, the base plate 1
A shallow recess is formed on the inner surface side of 0, and a single valve plate 14 made of steel is fitted into this recess. In the base plate 10 and the valve plate 14, two communication holes 10a and 14a are unevenly distributed on one side in the left-right direction and are opened in the horizontal direction at intervals. A pressure feed pump connection port 11 and a water feed pump connection port 12 (not shown in FIG. 5) are separately provided on one surface of the base plate 10 so as to communicate with the communication holes 10a and 14a. The pressure feed pump connection port 11 is connected to the pressure feed pump T. The water supply pump connection port 12 is connected to a high-pressure water supply pump 5 (shown in FIGS. 10 and 11) for supplying cleaning water or the like. The pressure pump connection port 11 and the water pump connection port 12 are formed by an inflow pipe 13.
Each inflow pipe 13 has the same diameter and is formed of a tubular body made of short steel. A flange 13a is formed at the end portion, and is fixed to the base plate 10 by a bolt 13b (not shown in FIG. 6) that inserts the flange 13a. The communication hole 10 is larger than the diameter of the communication holes 10a and 14a.
The distance between a and 14a is large. Guides 15a and 15b (not shown in FIG. 6) are fixed to the upper and lower edges of the base plate 10. Guides 15a, 15b
Is a rod-shaped member having a substantially L-shaped cross section as shown in FIG.
It is fixed by bolts. These guides 15a, 1
The slide plate 20 is slidably inserted between 5b.

The slide plate 20 is a steel plate-like member having a substantially rectangular shape in a front view. A concave portion is formed on the inner side surface of the slide plate 20, and the valve plate 25 is formed in the concave portion.
Has been inserted. When the slide plate 20 slides, the valve plate 25 slides with respect to the valve plate 14 and slides together with the slide plate 20. In the slide plate 20 and the valve plate 25, communication holes 20a, 25a are formed on one side in the left-right direction and are formed at regular intervals in the horizontal direction. A transport pipe connection port 21 (not shown in FIG. 5) and a drain pipe connection port 22 are separately provided so as to communicate with the communication holes 20a and 25a. Transport pipe connection port 21
Is for communicating with the concrete pressure pump connection port when it is in the pressure feed position, and for communicating with the pressure pump connection port 11 when it is in the cleaning position. The drain pipe connection port 22 communicates with the water feed pump connection port 12 when the cleaning position is reached. The pressure feeding position is the position shown in FIG. 6, and the cleaning position is the position shown in FIG. As shown in FIGS. 5 and 6, the transport pipe connection port 21 and the drain pipe connection port 22 are formed by a discharge pipe 23. The discharge pipe 23 is a short steel tubular body having a flange 23a formed near the end on the slide plate 20 side, and has the same diameter as the concrete connection port and the water supply pump connection port 12. The discharge pipe 23 is provided on the surface of the flange 23a on the slide plate 20 side.
Is formed with a step portion 23b continuous in the circumferential direction. A pressure gauge 24 (see FIG. 6) is provided on the upper surface at the center of the length of each discharge pipe 23.
(Not shown) is attached.

Plungers of the hydraulic jacks 30 are connected via an arm 31 fixed to one end of the slide plate 20. The hydraulic jacks 30 are fixed to the guides 15a and 15b separately fixed to the upper and lower edges of the base plate 10 so as to extend and contract in the same direction in parallel with the longitudinal directions of the guides 15a and 15b. When each hydraulic jack 30 (not shown in FIG. 6) expands and contracts, the arm 31 fixed thereto pulls the slide plate 20 horizontally (to the right in FIG. 6), and the valve plate 25 slides on the valve plate 14. The slide plate 20 moves while moving. The case where the hydraulic jack 30 is extended is the cleaning position, and the case where it is retracted is the pressure feeding position. The outputs of both hydraulic jacks 30 are equal, and the maximum hydraulic pressure in the prototype was 140 kgf / cm 2. It is connected to a hydraulic pump that drives each hydraulic jack 30, a relief valve, and a switching valve 32 shown in FIG.
Regarding expansion and contraction of each hydraulic jack 30, a switching lever 32a
By. In each figure, hydraulic pump, oil tank,
The relief valve and the like are omitted.

As shown in FIG. 9, the pressing device 40 is roughly composed of a cylinder 41, a piston 42, and a hydraulic device.

The cylinder 41 is the flange 2 of the discharge pipe 23.
It is a steel tubular body fixed to the slide plate 20 with a space on the outer side surface between the slide plate 3a and the slide plate 20. The inner diameter of the cylinder 41 is equal to the outer diameter of the step portion 23b of the flange 23a, and the discharge pipe 2 is inserted into the cylinder 41.
The stepped portion 23b of No. 3 is fitted and fixed. Since the inner diameter of the cylinder 41 is equal to the outer diameter of the step portion 23b of the flange 23a, a gap equal to the wall thickness of the step portion 23b is formed.

The inner diameter of the piston 42 is equal to the outer diameter between the flange 23a and the slide plate 20 in the axial direction of the discharge pipe 23, and the outer diameter is the same as the inner diameter of the cylinder 41. , Discharge pipe 23 and cylinder 4
It is fitted so as to be slidable in the axial direction in a gap with respect to 1. A flange 42a is formed at the end of the piston 42 on the valve plate 25 side, and is directed radially inward. This collar 42a is locked to a locking portion 23c formed at the end of the discharge pipe 23,
It cannot be moved to the free end side of the discharge pipe 23. The length is from the step 23b of the discharge pipe 23 to the valve plate 25.
It is shorter than the length. Therefore, a gap 43 is formed between the step portion 23b of the discharge pipe 23 and the piston 42. A spring 44 is inserted into the gap 43 in a state of being urged in the axial direction, and presses the piston 42 against the valve plate 25.

An oil hole 41a communicating with the space 43 is opened in the side surface of the cylinder 41. The oil hole 41a is formed in an oil pipe 41b that extends radially outward on the side surface of the cylinder 41. An oil tube 45 is connected to the oil pipe 41b. The oil is pumped from the oil tube 45 and the gap 43 is filled with the oil.

In the present embodiment, the hydraulic device is a hydraulic pump (not shown) or the like to which each hydraulic jack 30 (shown in FIG. 3 and the like) is connected, and a hydraulic pressure equivalent to that of the hydraulic jack 30 is applied. . In the experiment, the hydraulic pressure (14
With 0 kgf / cm2), sufficient sealing was achieved. When hydraulic pressure is applied to the gap 43 by the hydraulic device, the piston 42 presses the valve plate 25 with its end surface in contact with the valve plate 14, and the cement paste component of concrete leaks from the sliding surface between the valve plate 25 and the valve plate 14. Prevent from doing.

Incidentally, each reference numeral 5 attached in each of the above drawings
0 is a seal ring.

Next, the pipe switching device A constructed as described above.
A spraying procedure and a cleaning operation in the case of using the concrete spraying apparatus B will be described with reference to FIGS. 10 and 11.

First, when concrete is sprayed, the slide plate 20 is moved to the pressure feeding position as shown in FIG. In the pumping position, the pumping pump connecting port 11 is the transport pipe connecting port 21.
Connected. That is, the concrete manufactured by the concrete manufacturing plant P is put into the hopper (not shown) of the pressure feed pump T, and then passes through the pressure feed pump connection port 11 and the transport pipe connection port 21 by the pressure feed pump T, and It is transported in D. In addition, the concrete pumped to the Y-tube Y
Along with the high pressure air supplied from the compressor C via the air supply pipe W, the air is conveyed in the spray hose F and discharged from the spray nozzle N at the tip. Further, hydraulic pressure is applied to the piston 42 shown in FIG. 9 to prevent the cement paste component of concrete from constantly leaking from the sliding surface (contact surface between the valve plate 25 and the valve plate 14).

Next, when the cleaning work is performed after the spraying work is completed, first, the switching lever 32a of the switching valve 32 shown in FIG. 4 is switched, and the slide plate 20 is slid to the cleaning position as shown in FIG. To do. In the washing position, as shown in FIG. 11, the water pump connection port 12 is connected to the transport pipe connection port 21, and the pressure pump connection port 11 is connected to the drain pipe connection port 22. Also, the water pump connection port 12
Is filled with a sponge ball 6 for cleaning, and the high-pressure water pump 5 is connected thereto. Further, a water tank (not shown) in which wash water is stored is connected to the high-pressure water pump 5.

In this state, washing water is sent from the high-pressure water pump 5 to the transport pipe D, the sponge balls 6 are gradually moved to the tip side in the transport pipe D, and the residual concrete in the transport pipe D is transported to the transport pipe D. And the inside of the transport pipe D is washed. At this time, the Y-shaped pipe Y provided at the tip of the transport pipe D is removed and the spray hose F is separated from the transport pipe D. Generally, the spray hose F has a smaller diameter than the transport pipe D. Therefore, if the spray hose F is washed while the transport pipe D and the spray hose F are connected, the sponge balls 6 moving in the transport pipe D block the spray hose F. This is because there is a possibility that Therefore, for cleaning the spray hose F, after discharging the sponge ball 6 from the tip of the transport pipe D, the Y-shaped pipe Y
Is connected to the transport pipe D, and high-pressure air is supplied from the Y-shaped pipe Y into the blowing hose F while the high-pressure water pump 5 pumps wash water under pressure.

On the other hand, in parallel with the cleaning operation of the transport pipe D, the cleaning operation of the concrete manufacturing plant P and the pressure pump T is performed. At that time, the cleaning drainage obtained by cleaning the slurry unit S, the mixing unit M, and the pressure pump T is discharged to a predetermined dump through the drain hose connected to the drain pipe connection port 22 of the pipe switching device A by the pressure pump T. To be done.

Since the pipe switching device A according to this embodiment is constructed as described above, it has the following effects.

Since the cleaning of the concrete manufacturing plant P and the pressure pump T and the cleaning of the transport pipe D can be performed at the same time, the cleaning time can be shortened. As shown in the time chart of FIG. 12, when the pipe switching device A is not used, the slurry unit cleaning step a, the mixing unit cleaning / pressure pump cleaning step b, and the cleaning water storage step c
And the transport pipe cleaning step d cannot be performed at the same time.
In the figure, step e is a spray hose cleaning step. On the other hand, as shown in the time chart of FIG. 13, when the pipe switching device A is used, the slurry unit cleaning step c ′, the mixing unit cleaning / pressure pump cleaning step d ′, and the transport pipe cleaning step a 'And can be done at the same time. Therefore, for example, the total length of the transport pipe D is 20
In case of 0m, total cleaning time is 4/7
In addition, the time can be reduced by about 30 minutes.

When the pipe switching device A is used,
Since the high-pressure water pump 5 is used, water previously stored in a water tank (not shown) can be directly sucked and used, and the washing water storage step c is unnecessary.

Further, as shown in the time chart of FIG.
When the pipe switching device A was not used, the cleaning work was performed by three people. On the other hand, when the pipe switching device A shown in the time chart of FIG. 13 was used, the cleaning work was performed by two people. Therefore, the number of washers can be reduced.

Therefore, if the pipe switching device A is used, the cleaning time can be shortened and the number of cleaning workers can be reduced. As a result, the construction cost can be reduced.

Further, in the past, when the pressure pump pumped fresh water during the cleaning of the transport pipe D, water leakage might occur. However, when the pipe switching device A is used, the water pump pumps the wash water. Therefore, the problem of leakage does not occur (usually, concrete pumps, especially piston pumps, gradually wear when the valve and cylinder parts are worn over a long period of time, and when the fresh water is pumped under high pressure, this wear Often leaks from the part).

The predetermined distance between the pressure pump connection port 11 and the water pump connection port 12 provided on the base plate 10 is defined by the communication holes 10a, 14a, 20a, 2 and 2.
Since it is larger than the diameter of 5a, as shown in FIG. 8, the pressure pump connection port 11 and the water pump connection port 12 are the drain connection port 22 and the transport pipe connection port 21.
It can be set to a position that does not communicate with (intermediate position). Providing this intermediate position has the following advantages. Usually, the trouble of blocking the transportation pipe D often occurs near the discharge port of the pressure pump T, and the disconnection operation of the transportation pipe D near the pressure pump T is very frequently performed.
Conventionally, when concrete is pumped to a high place by this type of concrete transport device, a transport pipe D near the pump is provided.
It was very dangerous to separate the concrete because the concrete in the upstream transport pipe flows backward. However, by setting the pipe switching device A to the intermediate position as described above, it is possible to completely prevent the reverse flow of concrete and safely perform the work of separating the transport pipe D in the vicinity of the pressure pump T. .

Further, since the pressing device 40 is provided, it is possible to prevent the cement paste component of concrete from leaking from the sliding surface (the contact surface between the valve plate 25 and the valve plate 14), and the inside of the transport pipe D can be prevented. Does not impair the pumpability of concrete. In addition, in the present embodiment, the pressure feed pump connection port 11 is provided on the base plate 10.
And a water pump connection port 12 are provided, and the slide plate 20 has a transport pipe connection port 21 and a drain pipe connection port 2.
Although the one provided with 2 has been illustrated, conversely, the slide plate 2
0 may be provided with the pressure pump connection port 11 and the water pump connection port 12, and the base plate 10 may be provided with the transport pipe connection port 21 and the drain pipe connection port 22.

Also, regarding the pressing device 40, in the present embodiment, the structure in which the valve plate 25 on the slide plate 20 side is pressed against the valve plate 14 on the base plate 10 side is shown, but conversely, in FIG. It is of course possible to adopt a configuration in which the valve plate 114 on the base plate 110 side is pressed against the valve plate 125 on the slide plate 120 side like the pressing device 140 shown. In FIG. 14, reference numeral 141 is a cylinder, 142 is a piston, 143 is a gap, and 144 is a spring.

Further, although it slides in the horizontal direction, the present invention is not limited to this, and it is possible to slide in the vertical direction. It can also slide in the direction of rotation.

Further, although the pipe switching device A according to the above-mentioned embodiment is applied to the concrete spraying device, the raw concrete or the like conveyed by the raw concrete truck is pressure-fed in the transportation pipe D by the concrete pressure pump to form the form. It can also be applied to ordinary concrete pouring inside.

The surface of the valve plate can be processed with polytetrafluoroethylene or the like.

Further, the number, position, shape, etc. of the above-mentioned constituent members are not limited to those in the above-mentioned embodiment, and the number, position, shape, etc. suitable for carrying out the present invention can be adopted.

In the above figure, the same components are designated by the same reference numerals.

[0045]

Since the present invention is configured as described above, the concrete pressure pump and the transport pipe can be cleaned at the same time, so that the cleaning time can be shortened.
As a result, according to the present invention, the construction period can be shortened and the construction cost can be reduced.

[Brief description of drawings]

FIG. 1 is a conceptual diagram of a concrete spraying device.

FIG. 2 is a plan view of a pipe switching device.

FIG. 3 is a front view of a pipe switching device.

FIG. 4 is a side view of the pipe switching device.

5 is a cross-sectional view taken along line yy of FIG.

6 is a sectional view taken along line xx of FIG. 3 (a lateral sectional view showing a pumping position of the pipe switching device).

FIG. 7 is a cross-sectional view showing a cleaning position of the pipe switching device.

FIG. 8 is a cross-sectional view showing an intermediate position of the pipe switching device.

FIG. 9 is an enlarged cross-sectional view of a pressing device.

FIG. 10 is a conceptual diagram showing a pumping position of a pipe switching device.

FIG. 11 is a conceptual diagram showing a cleaning position of the pipe switching device.

FIG. 12 is a diagram showing a conventional time chart for cleaning.

FIG. 13 is a diagram showing a time chart during cleaning in the present embodiment.

FIG. 14 is a cross-sectional view of a pipe switching device according to another embodiment.

[Explanation of symbols]

 A pipe switching device C compressor D transport pipe H sand hopper M mixing unit N spray nozzle P concrete manufacturing plant S cement silo T concrete pump U slurry unit W Y pipe air pipe Y Y pipe Z pressure control device 1 stand 2 vibration isolation Rubber 3 plates 5 High pressure water pump 6 Sponge ball 7 Drain pipe 10 Base plate 10a Communication hole 11 Pressure pump connection port 12 Water pump connection port 13 Inflow pipe 13a Flange 13b Bolt 14 Valve plate 14a Communication hole 15a, 15b Guide 20 Slide plate 20a Communication hole 21 Transport pipe connection port 22 Drain pipe connection port 23 Discharge pipe 23a Flange 23b Step 23c Locking part 24 Pressure gauge 25 Valve plate 25a Communication hole 30 Hydraulic port Kick 31 Arm 32 Switching valve 32a Switching lever 40 Pressing device 41 Cylinder 41a Oil hole 41b Oil pipe 42 Piston 42a Brim 43 Air gap 44 Spring 45 Oil tube 50 Seal ring 110 Base plate 111 Pressure pump connection port 112 Water pump connection port 114 Valve plate 120 Slide Plate 121 Transport Pipe Connection Port 122 Drain Pipe Connection Port 125 Valve Plate 140 Pressing Device 141 Cylinder 142 Piston 143 Void 144 Spring

Claims (4)

[Claims] 1. A pipe switching device used in a concrete transportation device for pumping fresh concrete through a transportation pipe by a concrete pressure pump, the base plate, a slide plate slidably provided on the base plate, and the slide. A movable means for sliding a plate, the base plate, a concrete pressure pump connection port connected to the concrete pressure pump, and a water pump connection connected to a water pump for supplying water for cleaning, etc. A port is provided via a space, and the slide plate slides to communicate with the concrete pressure pump connection port when the slide plate is in the pumping position, and is connected to the water pump when it is in the cleaning position. The transport pipe connection port communicating with the port and the cleaning position A drainage pipe connection port communicating with the concrete pressure pump connection port when the water pressure becomes high is provided via an interval equal to the interval between the concrete pressure pump connection port and the water pump connection port. Pipe switching device. 2. A pipe switching device used in a concrete transportation device for pumping fresh concrete through a transportation pipe by a concrete pressure pump, comprising a base plate, a slide plate slidably provided on the base plate, and the slide. A movable means for sliding a plate, the slide plate, a concrete pressure pump connection port connected to the concrete pressure pump,
A water supply pump connection port connected to a water supply pump for supplying water for cleaning or the like is provided with a gap, and the slide plate slides on the base plate when the pressure transfer position is reached. A transport pipe connecting port that communicates with the concrete pressure pump connection port and communicates with the water pump connection port when in the cleaning position, and a drain pipe that communicates with the concrete pressure pump connection port when in the cleaning position The pipe switching device, wherein the connection port is provided via a space equal to the space between the concrete pressure pump connection port and the water pump connection port. 3. The interval between the concrete pressure pump connection port and the water pump connection port is larger than the inner diameter of the transportation pipe connection port.
Alternatively, the pipe switching device according to item 2. 4. The base plate and the slide plate are respectively provided with valve plates in contact with each other, and one of the valve plates is provided with another valve plate so that fresh concrete, mortar, etc. do not leak from a surface where the valve plates are in contact with each other. 4. The pipe switching device according to claim 1, further comprising a pressing unit that presses the valve plate.