JPH0137183Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid sealing device used in cleaning the inside of a transport pipe connected to a concrete pump.

By a concrete pump with a transport pipe,
When ready-mixed concrete (hereinafter abbreviated as "ready-mixed concrete") is pumped to a pouring site, it is necessary to discharge the ready-mixed concrete remaining in the transport pipe after the pumping work is completed. To discharge this residual ready-mixed concrete, conventionally, in addition to the concrete pump, an air compressor, multistage centrifugal pump, or reciprocating water pump was connected to the transport pipe to pump air and water into the transport pipe. It was being discharged by However, in addition to the concrete pump itself, the concrete pump truck also has an air compressor as mentioned above.
Alternatively, if the vehicle is equipped with various pumps, the weight and size of the vehicle will increase, resulting in a disadvantage in terms of product cost.

Therefore, it is possible to use the concrete pump itself to pump water into the transport pipe, but between a pair of concrete cylinders connected to the fresh concrete hopper and the transport pipe, each concrete cylinder is alternately connected to the transport pipe. In the case of a concrete pump with a swingable switching pipe, there is a slight gap between the concrete cylinder and the switching pipe due to its structure, and sand and pebbles can get caught in this gap, causing damage to both sides. When the ends become worn due to sliding, water leaks from there and the water pressure inside the concrete cylinder cannot be maintained. Therefore, it is necessary to attach a required liquid sealing member to the connection part to maintain watertightness. However, because the above-mentioned connection part is located at the back of the switching pipe, it is difficult to securely attach the liquid sealing member in the specified position, and even if it can be installed, the liquid sealing member will easily come off when high water pressure is applied. There was a problem with it being torn or torn.

This invention was made in view of the above circumstances,
An object of the present invention is to provide a liquid sealing device for a concrete pump in which a liquid sealing member can be easily and reliably installed in a predetermined position, and the liquid sealing member does not come off even under high water pressure. do.

In order to achieve the above object, the present invention includes a ready-mixed concrete hopper, a pair of concrete cylinders connected to the ready-mixed concrete hopper, one end of which is connected to a transport pipe and is swingably provided within the ready-mixed concrete hopper,
A concrete pump comprising a switching pipe whose other end is moved along the inner surface of the peripheral wall of the fresh concrete hopper and connected alternately to the discharge ports of the pair of concrete cylinders, the other end of the switching pipe having:
A liquid sealing member made of an elastic material such as rubber, whose wall thickness increases from the inner end to the outer end and has a tapered shape where the inner circumferential surface is removed, is switched from the thick outer end to the above. It is inserted so as to protrude from the other end of the pipe and come into contact with the inner surface of the peripheral wall of the ready-mixed concrete hopper,
A configuration in which the fixture is detachably pressed against the inner circumference of the switching pipe by a plurality of pressing parts of a fixing jig, which is expanded radially according to the shape of the inner circumferential surface of the liquid sealing member by operating a screw member. That is.

Hereinafter, one embodiment of the present invention will be described with reference to FIGS. 1 to 7.

First, A in the figure shows a well-known concrete pump, in which a fresh concrete hopper 1 and a pair of circulation holes 1b adjacent to each other in the peripheral wall 1a of the fresh concrete hopper 1 are connected to a discharge port 2a which also serves as an inlet. A pair of concrete cylinders 2 each connected to
Then, one end to which the wear ring 3a is attached is swung in the directions of arrows A and B in the figure while aligning the inner surface of the peripheral wall 1a of the ready-mixed concrete hopper 1, and the one end is alternately inserted into the pair of communication holes 1b. It is equipped with a switching pipe 3 in the form of a bent pipe to be connected, and the other end 3b of the switching pipe 3 is connected to a transport pipe 4. When the piston 2b in one concrete cylinder 2 slides away from the ready-mixed concrete hopper 1, the switching pipe 3 is communicated with the other concrete cylinder 2, and the intake of ready-mixed concrete into the above-mentioned one concrete cylinder 2 is stopped. At the same time, the ready-mixed concrete in the other concrete cylinder 2 can be freely pumped to the transport pipe 4. Further, when the piston 2b in one concrete cylinder 2 slides in the direction approaching the ready-mixed concrete hopper 1, the switching pipe 3 swings and is communicated with this one concrete cylinder 2. The ready-mixed concrete inside can be freely pumped into the transport pipe 4, and the ready-mixed concrete can be freely sucked into the other concrete cylinder 2. The communication hole 1b of the ready-mixed concrete hopper 1 is provided with an annular wear plate 5a and a sleeve 5b.

The liquid sealing device of the present invention is provided in the above concrete pump A by forming a gap between the switching pipe 3 and the concrete cylinder 2, that is, between the wear ring 3a of the switching pipe 3 and the wear plate 5a of the communication hole 1b of the ready-mix concrete hopper 1. As shown in FIG. 2, the end surface of one end (outer end) 6a of the connecting portion is brought into contact with the wear plate 5a, and the outer circumferential surface is brought into contact with the wear plate 5a. 3a and a cylindrical liquid sealing member 6 tightly fitted to the inner peripheral surface of the switching pipe 3, and a cylindrical liquid sealing member 6 provided inside the liquid sealing member 6 to tightly fix the liquid sealing member 6 to the connection portion. It consists of a fixing jig 7.

The liquid sealing member 6 is made of a rubber material such as natural rubber or synthetic rubber, and the wear plate 5
One end 6a that is brought into contact with a is a thick wall portion,
Moreover, the inner diameter becomes smaller as it approaches the one end 6a, and an uneven portion 6b is formed along the circumferential direction on the outer peripheral surface.

On the other hand, the fixing jig 7 has a female threaded portion 8a formed at the center of one end surface, and a guide cylinder 8a formed on the peripheral wall.
Four through holes 8c in which b are arranged in a row are arranged in the circumferential direction.
A cylindrical jig body 8 is provided with holes drilled at a pitch of 90°, a wedge portion 9a is provided at one end, and an engagement hook 9b is provided at the other end. The jig main body 8 is positioned inside the jig body 8 and the engaging hook 9b is positioned outside the jig body 8.
a screw member 9 screwed into the female threaded portion 8a;
Four arm members 10 are movably inserted into the through hole 8c of the jig main body 8 and the guide tube 8b with one end in contact with the outer peripheral surface of the wedge portion 9a of the screw member 9, and protrude from the guide tube 8b. and arcuate pressing portions 11 provided at the other ends of the arm members 10, respectively. The outer surface of each of the pressing portions 11 forms a virtual conical surface whose diameter decreases as it approaches one side, and its front surface is brought into close contact with the inner circumferential surface of the liquid sealing member 6. ing. Then, when the screw member 9 is screwed in,
The wedge portion 9a moves in the direction of arrow C in the figure, and each arm member 10 moves radially in the radial direction of the jig main body 8. As a result, each pressing portion 11 is expanded, and the liquid sealing member 6 is moved in the above-mentioned direction. It is designed to be tightly fixed to the connection part. Note that a stopper member 12 of the screw member 9 is provided on the other side of the jig main body 8.

Therefore, after the concrete pump A finishes pumping the ready-mixed concrete, when the liquid sealing device having the above configuration is used to discharge the ready-mixed concrete remaining in the transport pipe 4,
First, the concrete cylinder 2 is stopped, the switching pipe 3 is stopped, and then the transport pipe 4 is stopped.
from this switching pipe 3. Next, using a suitable mounting tool, the liquid sealing member 6 is inserted into the switching pipe 3 with its one end 6a facing forward.
Then, it is inserted until the end surface of one end 6a abuts on the wear plate 5a. At this time, the outer peripheral surface of the liquid sealing member 6 is fitted into the inner peripheral surface of the wear ring 3a and the switching pipe 3, and the gap between the wear plate 5a and the wear ring 3a is sealed. In this state, the fixing jig 7 is inserted into the switching pipe 3 as shown in the figure, and positioned inside the liquid sealing member 6. Subsequently, the hook portion 9b of the screw member 9 is rotated in a predetermined direction, and the screw member 9 is screwed into the jig main body 8. Then, the wedge portion 9a moves further forward, and its peripheral surface moves each arm member 10 radially outward of the jig main body 8, whereby each pressing portion 11 is expanded radially, One end 6 of the liquid sealing member 6
The end surface of a is pressed against the wear plate 5a, and the uneven portion 6b on the outer peripheral surface is pressed against the inner peripheral surfaces of the wear ring 3a and the switching pipe 3, so that the gap between the wear plate 5a and the wear ring 3a is completely sealed.

Then, a filler that separates water and ready-mixed concrete is inserted into the transport pipe 4, the switching pipe 3 and the transport pipe 4 are connected, water is poured into the ready-mixed concrete hopper 1, and the concrete cylinder 2 is filled with water.
and the switching pipe 3 are operated, water is sent to the transport pipe 4 at high pressure by the piston 2b of the concrete cylinder 2, and the remaining ready-mixed concrete in the transport pipe 4 is discharged.

Here, in the case of the liquid sealing device, the liquid sealing member 6
is formed into a tapered shape with the wall thickness increasing from the inner end (the right end in FIG. 2) to the outer end 6a so that the inner peripheral surface is removed, and Since the outer surface of the pressing portion 11 of the fixing jig 7 is also tapered to match the shape of the inner circumferential surface of the liquid sealing member 6, the liquid sealing member 6 can not only be expanded in its radial direction; The one end 6a is also pressed toward the side. Therefore, one end 6a is firmly pressed against the end surface of the wear plate 5a, and the sealing is complete. Further, since the one end 6a of the liquid sealing member 6 is formed in a thick wall shape, it will not be greatly deformed or turned over due to the swinging movement of the switching pipe 3, and will not wear easily and have good durability. It is.

Note that after the cleaning work of the transport pipe 4 is completed, the fixing jig 7 and the liquid sealing member 6 are removed. To remove the fixing jig 7, rotate the screw member 9 in the opposite direction to expand each pressing part 11. All you have to do is release the opening force and just let it stick out from the switching pipe 3.

Further, in the above embodiment, each arm member 1
0 can be moved in a direction perpendicular to the screwing direction of the screw member 9, but it is configured to move radially in an oblique direction inclined toward the screwing direction with respect to the screwing direction. In that case as well, the outer surface of the pressing portion 11 is made to be in complete contact with the inner circumferential surface of the liquid sealing member 6.

As explained above, the liquid sealing device in the concrete pump according to the present invention includes a ready-mixed concrete hopper, a pair of concrete cylinders connected to the ready-mixed concrete hopper, and one end of which is connected to a transport pipe and can swing freely within the ready-mixed concrete hopper. A concrete pump equipped with a switching pipe whose other end is moved along the inner surface of the peripheral wall of the ready-mixed concrete hopper and connected alternately to the discharge ports of the pair of concrete cylinders. A liquid sealing member made of an elastic material such as the above is inserted with its outer end protruding from the other end of the switching pipe and in contact with the inner surface of the peripheral wall of the ready-mixed concrete hopper, and is pressed by the plurality of pressing parts of the fixing jig. Since it is configured to be pressed against the inner periphery of the switching pipe and detachably attached, it is possible to reliably seal the gap that occurs at the connection part of the switching pipe to the concrete cylinder.

Moreover, the liquid sealing member is formed into a tapered shape whose wall thickness increases as it goes from the inner end to the outer end to remove the inner peripheral surface. The structure is such that the fixing jig is removably pressed against the inner periphery of the switching pipe by a plurality of pressing parts of the fixing jig that expand radially to match the shape of the surface. The liquid sealing member will not be significantly deformed, turned over, or torn by dynamic motion and high water pressure, and will not wear easily and have good durability.
In addition, the outer end of the liquid sealing member is pressed against the inner surface of the peripheral wall of the raw concrete hopper by the pressure of the pressing part of the fixing jig, which also has the effect of improving the degree of sealing.

[Brief explanation of the drawing]

Figures 1 to 6 show an embodiment of the present invention. Figure 1 is a sectional view showing a concrete pump equipped with a liquid sealing device, and Figure 2 is a cross-sectional view of the oval part of Figure 1. Enlarged view, Figure 3 is a half-sectional view of the liquid sealing device,
Figure 4 is a view in the - arrow direction of Figure 3, Figure 5 is a side view of the fixing jig, Figure 6 is a view in the - arrow direction of Figure 5, and Figure 7 is a partially broken view of the concrete pump. FIG. 1... Fresh concrete hopper, 2... Concrete cylinder, 3... Switching pipe, 4... Transport pipe, 6...
Liquid sealing member, 7...Fixing jig.

Claims (1)

[Scope of utility model registration request] A ready-mixed concrete hopper 1, a pair of concrete cylinders 2 connected to the ready-mixed concrete hopper 1, one end of which is connected to a transport pipe 4 and is swingably provided within the ready-mixed concrete hopper 1, and the other end of which is connected to the peripheral wall of the ready-mixed concrete hopper 1. In the concrete pump, the switching pipe 3 is moved along the inner surface of the concrete cylinder 1a and connected alternately to the discharge ports 2a of the pair of concrete cylinders 2. A liquid sealing member 6 made of an elastic material such as rubber and having a tapered shape that increases toward the end and removes the inner peripheral surface connects the thick outer end from the other end of the switching pipe 3. It is projected and inserted into contact with the inner surface of the peripheral wall 1a of the ready-mixed concrete hopper 1, and is expanded radially according to the shape of the inner peripheral surface of the liquid sealing member 6 by operating the screw member 9.
A liquid sealing device for a concrete pump, characterized in that it is pressed against the inner periphery of a switching pipe 3 by a plurality of pressing parts 11 of a fixing jig 7 and is detachably attached.