JPS594555B2 - Switching device for suction section in concrete pump - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a concrete pump equipped with a pair of pump cylinders that are driven by a mutually created force, in which concrete in a hopper is alternately sucked into the pair of pump cylinders, and the sucked concrete is pumped into one pump cylinder. This invention relates to a switching device for a suction section in a concrete pump for pressure feeding into a discharge pipe of a concrete pump.

Generally, in the conventional suction section switching device for the concrete pump, as shown in FIG. It is always connected to the discharge pipe 05, and the other end is connected to a pair of pump cylinders 03.
, 03' so that they can communicate with each other, and the concrete in the hopper 01 is alternately connected to the pair of pump cylinders 0.
3°03', and the sucked concrete is pumped through the switching pipe 09 to the discharge pipe 05. However, with the switching device, the concrete is pumped in the direction shown by the arrow in Fig. 6 when concrete is pumped. A pumping force F acts on the switching conduit 09, and this force acts as a torsional moment on the switching conduit 09, and as shown in FIG.
A gap is created at the joint between 3' and the switching conduit 09, and the concrete passing through the joint is instantly separated and its fluidity is deteriorated, and aggregate in the concrete collects in the gap. This has the disadvantage of gradually accumulating, gradually narrowing the flow path, and eventually clogging it.

In view of the above, the present invention prevents high pressure from acting on the switching conduit, and utilizes the internal pressure in the suction chamber to prevent the joint between the conduit and a pair of pump cylinders from separating. It is an object of the present invention to provide a switching device for a suction section in a concrete pump having a simple structure and capable of eliminating the drawbacks of conventional pumps.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Below a hopper 1 into which concrete is charged, a suction surface 2 in which a suction chamber C is formed is provided.

One ends of a pair of pump cylinders 3, 3' are connected to one end wall of the suction surface 2, and their open ends 4.4' communicate with the interior of the suction chamber C.

A discharge pipe 5 is connected to the other end wall of the suction surface 2, and a transfer pipe 6 is connected to the outer end of the discharge pipe 5.

The suction surface 2 is connected to the hopper 1 and a pair of pump cylinders 3, 3.
! It is divided into a base 2□ provided on the discharge pipe 5 and a tip 2° provided on the discharge pipe 5, and the tip 2□ is hinged 7 to the base 2□ so that it can be opened and closed, and they are held together by a locking tool 8. It is meant to be combined.

In the suction chamber C, a switching conduit 9 having an angular shape in longitudinal section is supported so as to be swingable about a vertical axis LL.

An elbow-shaped concrete flow passage 11 is vertically formed in the switching conduit 9, and the upper opening end of this flow passage 11 is always in communication with the discharge port of the hopper 1, and the lower opening end thereof is an arc-shaped concrete flow passage 11. It is opened at the moving end q, and as will be described in detail later, the concrete flow path 1 is opened by the left and right swinging of the switching pipe 9.
1 can be alternately communicated with a pair of pump cylinders 3, 3'.

As clearly shown in FIG. 2, a drive shaft 12 having a square cross section is integrally protruded from the lower end of the switching conduit 9.
A fan-shaped pinion 13 is fixed to the.

A pair of brackets 14.14' are provided on both sides of the lower surface of the suction surface 2.
are suspended, and a pair of rack cylinders 15, 15' are fixed to the brackets 14, 14' facing each other on the same axis, and the rack cylinders 15, 15' have the above-mentioned Both ends of a rack rod 17 having a rank 16 carved therein and meshed with the pinion 13 are slidably inserted therein.

A piston 18 is slidably fitted into each of the pair of rack cylinders 15, 15', and each piston 18 is in contact with the end surface of the rack rod 17, respectively.

Fluid chambers 19 are formed in each of the pair of rack cylinders 15 and 15', and by alternately feeding pressurized fluid into these fluid chambers 19, the rack rod 17 is reciprocated left and right, and a pinion that is interlocked therewith. 13 via switching conduit 9
can be forced to swing left and right.

As shown in Fig. 3, a pair of pump cylinders 3゜3'
The opening ends 4, 4' into the suction chamber C are formed into arcuate concave surfaces centered on the swing center of the switching conduit 9.
.

Mounting bolts 21 are screwed into both side walls of the suction surface 2 along the tangential direction of the arc surfaces at both ends of the tenth metal 20, and the inner ends of the mounting bolts 21 are inserted into both sides of the tenth metal 20. The tenth ring 20 can be aligned with the arcuate concave opening ends 4° 4' of the pair of pump cylinders 3 and 3' by tightening or reducing the tightening of the mounting bolt 21.

In this case, by making the bending radius of the tenth metal 20 slightly larger than the arc radius of the opening ends 4, 4' before installation, the mounting bolt 21 can be
The pressing force allows the tenth metal 20 to be brought into close contact with the arcuate concave opening ends 4, 4' of the pair of pump cylinders 3, 3'.

A 20th metal 22 is slidably fitted to the swinging end γ of the switching conduit 9 so as to be able to move forward and backward relative to the 10th metal 20, and a flange is provided at the tip of the 20th metal 22. Part 23
The outer surface of the flange portion 23, that is, the surface facing the tenth metal 20, is formed into an arcuate convex surface centered on the center of swing of the switching conduit 9.

Further, an annular pressure receiving surface 24 that increases the internal pressure in the suction chamber C is formed on the back surface of the flange portion 23, and this pressure receiving surface 24
When the internal pressure in the suction chamber C acts on the 20th gold 22, the 1st gold
It is energized so that it is pressed against gold 20.

In the figure, reference numeral 25 denotes a guide member provided in the suction chamber C, which guides the concrete discharged from the pair of pump cylinders 3, 3' toward the discharge pipe 5, and also reinforces the suction surface 2.

Next, the operation of the embodiment of the present invention will be explained. When the concrete pump is now driven, the pair of pump cylinders 3 and 3' and the pair of rack cylinders 15 and 15' are alternately operated at a predetermined timing. These operations are performed by conventionally known means, and the switching conduit 9 swings back and forth from side to side, and the concrete flow passage 11 of the switching conduit 9 communicates with one of the pump cylinders 3 or 3' during the suction stroke. The concrete in the hopper 1 is sucked into the pump cylinder 3 or 3', and the other pump cylinder 3' or 3, which is in the discharge stroke, communicates with the suction chamber C and transfers the concrete sucked into the suction chamber C. through the pair of pump cylinders 3, 3.
While the pair of rack cylinders 15 and 15' operate, the above-mentioned blowing operation is repeated, and the concrete in the hopper 1 can be continuously pumped into the discharge pipe 5.

By the way, as mentioned above, during concrete suction, the concrete flow path 11 of the switching pipe 9 is connected to the discharge pipe 5 on the high pressure side.
Hopper 1 on the low pressure side is opened to the atmosphere without being communicated with
Since the switching conduit 9 is connected to the pump cylinder 3,
The high-pressure concrete pumping force caused by 3' is not applied, and the concrete is not subjected to a large torsional moment.

In addition, the internal pressure in the suction chamber C due to the pressure feeding of concrete acts on the pressure receiving surface 24 of the 20th metal 22, and this 20th metal 22
Since they are pressed against the 10th metal 20, the 1st and 20th metals 20 and 22, which are in sliding contact with each other, are brought into close contact with each other without creating any gaps.

As described above, according to the present invention, the switching conduit 9 in the suction chamber C
One open end of the concrete flow path 11 formed in the hopper 1 is always connected to the hopper 1, and the other open end is connected to the switching conduit 9.
By swinging, the pump cylinders 3 and 3' are alternately connected to each other, so that the flow passage 11 is opened to the atmosphere and maintained at a low pressure, and a high pressure concrete pumping force acts on the switching conduit 9. Therefore, the switching conduit 9
The deformation of the switching conduit 9 can be prevented without excessive bending moment being applied to the cam.
are slidably fitted so that they can move forward and backward toward the 10th metal 20 on the pair of pump cylinders 3 and 3', and the 20th
The internal pressure in the suction chamber C is applied to the pressure receiving surface 24 formed on the metal 22, and the 20th metal 22 is brought into pressure contact with the 10th metal 20, so the internal pressure of the concrete in the suction chamber C is utilized. First. The sliding surfaces between the 20th gold 20 and 22 can always be kept in close contact with each other.

Therefore, the first function is achieved by preventing deformation of the switching conduit 9 and by utilizing the internal pressure in the suction chamber C. The joint action of the No. 20 metal 20.22 and the combined action prevent the joint between the pair of pump cylinders 3, 3' and the switching conduit 9 from separating, thereby causing all the problems and disadvantages of the conventional methods as described above. This ensures efficient and smooth concrete suction action at all times.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional side view of the suction section of a concrete pump equipped with the device of the present invention, Fig. 2 is a bottom view thereof, Fig. 3 is a cross-sectional bottom view taken along line III-III in Fig. 1, and Fig. 4 is Fig. 3 FIG. 5 is a vertical cross-sectional side view of the conventional device, and FIG. 6 is a vertical cross-sectional view showing the concrete transfer state of the conventional device. C... Suction chamber, 1... Hopper, 2...
...Suction surface, 3.3'...Pump cylinder, 5...Discharge pipe, 9...Switching conduit, 1
1... Concrete flow path, 20°22...
...First. 20th gold, 24... Pressure receiving surface.

Claims (1)

[Claims] 1 A suction surface 2 with a suction chamber C formed therein is connected to the lower part of the hopper 1, and one end wall of this suction surface 2 has a suction chamber C formed therein.
A pair of pump cylinders 3.3' are connected to the other end wall, and a discharge pipe 5 is connected to the other end wall, and a discharge pipe 5 is connected to the suction chamber C.
1 is installed in a swingable manner, and when one open end of the concrete flow path 11 is constantly communicated with the hopper 1, the other open end is connected to the switching conduit 9.
By the swinging of the pump cylinders 3, 3', the pair of pump cylinders 3, 3' are alternately communicated with each other.
If a No. 10 gold plate 20 is installed at the opening end of the suction chamber C crest, the tile will also be
A 20th metal 22 that can be in sliding contact with the 10th metal 20 is slidably fitted to the swinging end of the switching conduit 9 so as to be able to move forward and backward with respect to the 10th metal 20. receives the internal pressure in the suction chamber C and transfers the 20th gold 22 to the 10th
A switching device for a suction part in a concrete pump, which is formed with a pressure receiving surface 24 for pressing against metal 20.