JPS595190Y2 - Flow path switching device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a flow path switching device for a concrete pump.

In a concrete pump, the ready-mixed concrete in the hopper is forced into the transport pipe by alternately repeating suction and pressure feeding of the ready-mixed concrete using two piston pumps. A bent valve whose one end is always connected to one discharge pipe is used as a flow path switching valve to alternately repeat the operation of communicating the piston pump to the discharge pipe during discharge operation with the dual piston pump. There is a method in which a connecting pipe is provided in the hopper and is swung around the connection part with the discharge pipe as the center of rotation, and the other ends of the connecting pipe are alternately connected to the outlets of two piston pumps.

Although this type of flow path switching valve generally has good pumping performance, it has a problem with durability.

In other words, since the connecting pipes are alternately connected to the outlets of the two pressure-feeding cylinders, the two caps slide against each other in the presence of fresh concrete, causing wear and the gap between the caps increases. There is a problem in that fresh concrete aggregate gets stuck in the gaps, further accelerating the wear of the nozzle.

This device was devised to solve the above-mentioned problem. During the operation of alternately connecting the connecting pipe to the mouthpiece of the pressure-feeding cylinder, the mouthpieces are separated from each other, and when the switching is completed, the mouthpieces are separated from each other. It is an object of the present invention to provide a flow path switching device that allows close contact.

An embodiment of the present invention will be described below based on the drawings.

In FIGS. 1 to 4, 1 is a hopper of a concrete pump, and cylindrical members 3 and 4 are provided protruding from the lower part of the side wall 2 of the hopper, and slide onto the inner surface of the cylindrical members 3 and 4, respectively. A cylinder 7.8 is provided, and one end of a concrete pump suction cylinder 16. 17 and the inner surfaces of the cylindrical members 3 and 4 in their axial directions.

There is a bracket on the outer periphery of the front end of the slide cylinder 7.8)
9.10 is fixed, and this bracket) 9.10 is a connecting fitting 11a to the rods 11 and 12 of the hydraulic cylinder 13.14, which are respectively connected to the suction cylinder 16.17.
.

It is rotatably pin-coupled via 12a.

Reference numeral 15 denotes a connecting fitting that connects the slide cylinders 7.8 to each other, and connects and fixes the inner sides of the front end portions of the slide cylinders.

By actuating this hydraulic cylinder 13.14, the slide cylinder 7.8 can therefore be moved back and forth over a distance A (FIG. 4).

18.19 is a backing provided in an annular groove on the outer peripheral surface of the rear end of the slide cylinder to seal between the inner surfaces of the cylindrical members 3 and 4, and 20.21 is a backing provided on the inner surface of the front end of the slide cylinder 7.8. A backing provided in the annular groove on the circumferential surface seals between the outer circumference of the slope cylinder 16 and 17.

22 and 23 are seal rings provided at the tips of the slope cylinders 16 and 17.

A bearing housing 6 is provided on the rear wall 5 of the hopper 1, into which a backing 26 and a bearing 27 are fitted.

Reference numeral 28 denotes a discharge pipe, which is rotatably supported by a bearing 27. The front end (left side in Fig. 2) of the discharge pipe 28 opens into the hopper 1, and the rear end (right side in Fig. 2) opens into the hopper 1. It is connected to a tube (not shown).

Inside the hopper 1 is a connecting pipe 2 having an approximately S-shaped bend.
5 is provided, and its rear end is removably fixedly connected to the discharge pipe 28 with a bolt, nut, etc., and the front end base 2
9 faces the openings 7a, 8a of the slide cylinder 7.8.

A lever 30 is fixed to the outer peripheral surface of the discharge pipe 28,
The lever 30 is rotatably connected by a pin to a rod 31 of a hydraulic cylinder 32 supported by a shaft 34 on a bracket 33 fixed to the rear wall of the hopper 1 .

Therefore, by the operation of the hydraulic cylinder 32, the discharge pipe 28 is rotated within the range of angle θ, so that the center of the mouthpiece 29 of the connecting pipe 25 is aligned with the opening center 7b of the slide cylinder 7.8,
8b.

Next, the operation of the device of the present invention constructed as described above will be explained.

FIGS. 5(a) to 5(e) show the state of flow path switching in the device of the present invention, where (a) shows the opening end 8a of the slide cylinder.
is moved by the operation of the hydraulic cylinder 14 and comes into contact with the end surface of the mouthpiece 29 of the connecting pipe 25, and the two are in close contact with each other with a gap O.

Fresh concrete pumped from the slope cylinder 17 is discharged into a transport pipe through a connecting pipe 25 and a discharge pipe 28.
The open end 7a of the slide cylinder 7 opens into the hopper 1, and a slope cylinder 16 sucks fresh concrete.

Just before the end of the suction and discharge strokes of the slope cylinder 16.17, the slide cylinder 7.8 moves to the hydraulic cylinder 13.1.
Due to the operation of step 4, it moves by distance A to the left in the figure b)
At the same time, the connecting pipe 25 swings at an angle θ due to the operation of the hydraulic cylinder 32, so that its base 29 faces the open end 7a of the slide cylinder (C).

Due to the operation of the hydraulic cylinders 13 and 14, the slide cylinders 7 and 8 move by a distance A to the right in the figure, and the open end 7
a comes into close contact with the end surface of the base 29 of the connecting pipe 25 (
d).

Fresh concrete pumped from the slope cylinder 16 is discharged into the transport pipe through the slide cylinder 7, the connecting pipe 25, and the discharge pipe 28.

The open end 8a of the slide cylinder opens into the hopper 1,
Fresh concrete is sucked into the slope cylinder 16 (e
).

Sequence operations such as the movement of the pair of pistons of the concrete pump, the movement of the slide cylinder, and the rocking movement of the connecting pipe are performed by a known hydraulic flow path switching control circuit device (not shown). .

As explained above, the flow path switching device of the present invention has a slide cylinder which is opened in the front side wall of the hopper and reciprocated on the outer periphery of the frontage end side of the slope cylinder of the concrete hopper which communicates with the opening. On the other hand, a connecting pipe connected to a single discharge pipe rotatably provided on the rear wall of the hopper is provided in the hopper, and its mouthpiece is swung between the open ends of the two slide cylinders. Since the structure is configured so that the flow path for sucking and discharging fresh concrete is switched by moving the slide cylinder and communicating with the slide cylinder alternately, the slide cylinder and the connecting pipe are separated from each other when the flow path is switched, so that the mouth wear is avoided. Even if it wears out, the gap can be easily reduced by adjusting the stroke of the hydraulic cylinder that reciprocates the slide cylinder.

In addition, at the complete switching position, the caps are in close contact with each other and the gap can be set to O, which has the advantage of eliminating problems caused by fresh concrete aggregates getting caught in the conventional switching valves and sliding wear. has.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention; FIG. 1 is a longitudinal sectional view of the flow path switching device, FIG. 2 is a partially sectional plan view, FIG. 3 is a front view seen from the rear side, and FIG. FIG. 4 is a cross-sectional view showing the joint between the open end of the slide cylinder and the connecting pipe cap, and FIG. 5 is an explanatory view showing the flow path switching situation. 1...hopper, 2...front wall, 5...
... Rear wall, 7゜8 ... Slide cylinder, 7a, 8a ... Opening end, 16゜17 ...
...Slope cylinder, 25...Connection pipe, 28...
...Discharge pipe.

Claims (1)

[Scope of utility model registration request] In a pair of cylindrical openings provided at the bottom of one side wall of the hopper,
The suction side ends of the pair of suction cylinders of the concrete pump are communicated with each other, and the concrete pump slides between the outer periphery of the suction side end cylinder and the inner periphery of the hopper and the cylindrical opening in the axial direction of the cylinder. A slide cylinder configured to substantially expand and contract the suction side end of the suction cylinder is connected to the upper part of the other opposing side wall of the hopper so as to be swingable around the axis of the pipe. The concrete pump is equipped with a substantially S-shaped connecting pipe provided in the hopper so that one end is always in communication with the discharge pipe and the other end is in communication alternately with the slide cylinders of the pair of suction cylinders. Concrete provided with a fluid pressure cylinder device such that the slide cylinder slides forward during stroke and is closely connected to the end of the connecting pipe, and when the switching operation is performed, the slide cylinder retreats and separates from the end of the connecting pipe. Pump flow switching device.