JPS6129985Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a flow path switching device for a concrete pump used for conveying fresh concrete.

In a typical configuration of a concrete pump, 180
Each suction/discharge port of a pair of feeding cylinder devices operated with a phase difference of 1/2° faces the inside of the ready-mixed concrete input hopper, and a switching passage is formed between the suction/discharge port and the discharge pipe. By switching the passage in synchronization with the operation of the feeding cylinder device, the cylinder opening on the discharge operation side is communicated with the discharge pipe.

Regarding the structure of the flow path switching device that constitutes this switching flow path, various types have been proposed in the past, but all types have the following common drawbacks. .

(a) The flow pipes used to switch the flow paths of ready-mixed concrete have many non-linear parts such as bends and bends, and the cross-sectional area of the flow pipes tends to be uneven in the middle of the flow path. , an increase in pressure loss is unavoidable.

(b) In many structural parts, moving parts such as flow pipes and valves for switching the ready-mixed concrete flow path are assembled in such a way that they locally rub against other parts, making it difficult to avoid uneven wear of the parts. This reduces the durability of the entire device.

The present invention has been made in order to solve the above-mentioned problems, and the purpose of the present invention is to have a switching flow path that is close to a straight shape, and has no local sliding portion due to its structure. An object of the present invention is to provide a flow path switching device for a concrete pump.

The present invention will be explained below based on the illustrated embodiments.

In the flow path switching device of the embodiment, as shown in FIGS. 1 to 3, the front side of the box-shaped hopper 1,
That is, symmetrically shaped bosses 2A and 2B forming bearing parts are thickly molded on the left and right sides of the hem of the side plate 1a on the right side of the drawing, and inside each boss 2A and 2B, the side plate 1a
A receiving hole with a circular cross section is drilled through the side plate 1a at a slight angle from the vertical direction.

Therefore, each of the pair of left and right feeding cylinder devices 3
A and 3B are hydraulic cylinders 4 and 4 forming the front half.
The concrete cylinders 5, 5 forming the latter half are integrally connected, and each concrete cylinder 5 is slidably attached to the bosses 2A, 2B via bearings, seal members, etc. in the axial direction. inserted into the hole.

The coupling structure between the hydraulic cylinder 4 and the concrete cylinder 5 is such that an end plate 4a that closes the rear end of the hydraulic cylinder 4 and a diamond-shaped flange plate 5a provided at the front end opening of the concrete cylinder 5 are fastened with bolts. A hydraulic piston 7 and a concrete piston 8 are attached to the front and rear ends of the rod 6, which passes through the end plate 4a, respectively.

Furthermore, a pair of switching cylinder devices 9 for switching drive are provided on the front surfaces of the upper and lower parts of each flange plate 5a.
The rear end of the operating rod 10, which is fixedly installed in parallel with the feeding cylinder devices 3A and 3B and passes through the flange plate 5a rearward, is connected to a fork 11a of a rib 11 that projects above and below the bosses 2A and 2B. As a result, the cylinder device 3A and the cylinder device 3B are driven by the switching cylinder device 9, and the whole slides in the front-rear direction by a stroke _S2 .

Next, a discharge pipe 12 is attached to the center of the lower part of the rear side plate 1b of the hopper 1.
The inner opening of the hopper 1 communicates with an opening 1c provided in the hopper 1 located at the intersection of the extension axes of the two feeding cylinder devices 3A and 3B, and also communicates with the opening 1c of the hopper 1.
A cap ring 13 is fixed to the end face of c.

Therefore, the rear end of each concrete cylinder 5 is cut off diagonally to form the suction and discharge port end 1 of the pump.
4, 15, and when either one of the suction/discharge port end portions 14, 15 slides rearward, the suction/discharge port comes into close contact with the base ring 13.

The switching cylinder device 9 is connected to the feeding cylinder device 3.
It is formed to operate in the following sequence in synchronization with the operations of A and 3B.

The operating position shown in FIG. 1 shows that the concrete cylinder 5 of the left feeding cylinder device 3A is in the final stage of discharge operation, and the concrete cylinder 5 of the right feeding cylinder 3B is in the final stage of suction operation. Feeding cylinder 3A, 3B discharge (suction) completion → Feeding cylinder 3A forward movement → Feeding cylinder 3B backward movement → Feeding cylinder 3A, 3B suction (discharge) → Feeding cylinder 3B forward movement → Feeding cylinder 3A backward movement → Feeding cylinders 3A, 3B discharge (suction) → Return to the state shown.

Next, the operation of the switching device of the embodiment configured as described above will be explained.

Based on the above-described sequence operation of the hydraulic cylinder 4 and the switching cylinder device 9, the suction and discharge opening end of the concrete cylinder on the side that performs the discharge operation is connected to the discharge pipe 1.
On the other hand, the suction/discharge opening end of the concrete cylinder on the side that performs suction operation opens into the ready-mixed concrete in the hopper 1.

Therefore, every time both feeding cylinder devices 3A and 3B make one reciprocation, fresh concrete is pumped twice from the concrete cylinder 5 on the discharging side to the discharge pipe 12.

In this pressure feeding operation, the fresh concrete flow path is nearly linear and the cross-sectional area of the path is almost uniform, so pressure loss does not increase unnecessarily, and furthermore, the sliding of the cylindrical member Since the flow path is switched by movement alone, there is no local wear on the flow path members or fluctuations in fluid pressure associated with switching, which means that the pumping operation is performed efficiently. .

By the way, in the configuration of the above-described embodiment, the entire feeding cylinder device 3A, 3B is pressed against the discharge pipe 12,
It was configured so that they were separated, but instead of this,
As shown in the figure, the same switching operation is possible even when the feeding cylinder device 16 is fixedly installed.
Specifically, the hydraulic cylinder 17 of the feeding cylinder device 16 is fixedly held on the base 18, the flow pipe 20 is fitted onto the concrete cylinder 19 of the feeding cylinder device 16, and the flow pipe 20 is A single switching cylinder device 9 attached to the collar 20a provided thereon may be configured to reciprocate by a stroke _S4 , thereby connecting the pair of flow path pipes 20 to the discharge pipe 12 alternately. , the same operation and effect as described above can be obtained.

In addition, in this configuration, since the switching drive load is reduced by the fixed weight, the switching cylinder device 9 can smoothly slide the flow path pipe 20 even with a smaller capacity than the switching cylinder device of the embodiment shown in FIG. is possible.

As described above, according to the flow path switching device for a concrete pump according to the present invention, the linear suction and discharge port ends of the pair of feeding cylinders and the inward opening end of the discharge pipe are connected to each other within the hopper. Along with arranging it in opposition to the shape,
Since the suction and discharge port ends are connected to the discharge pipe alternately by operation drive, the flow path of fresh concrete from the concrete cylinder of the feeding cylinder device to the discharge pipe becomes almost straight, and the resistance of the switching flow path is reduced. Unnecessary increase and occurrence of uneven wear of the switching member are prevented,
This has the practical effect of improving the pumping performance and durability of the switching device.

[Brief explanation of drawings]

FIG. 1 is a plan view of a concrete pump flow switching device showing an embodiment of the present invention, FIG. 2 is a side sectional view taken along the - development line in FIG. 1, and FIG. FIG. 4, a partial front view in the direction of arrows, is a side sectional view of a switching device showing another embodiment, and corresponds to FIG. 2. 1... Hopper, 3A, 3B, 16... Feeding cylinder, 9... Reciprocating sliding drive switching cylinder, 12
...Discharge pipe, 14, 15, 20...Suction and discharge port end,
and a flow pipe as the same end.

Claims (1)

[Scope of utility model registration request] The suction and discharge port ends on each axis of the pair of ready-mixed concrete feeding cylinder devices and the inward opening end of the ready-mixed concrete delivery discharge pipe are arranged in a Y-shape in opposition to each other in the ready-mixed concrete hopper, and The suction/discharge port end is intermittently slid back and forth in the axial direction of the feed cylinder device in synchronization with the operation of the feed cylinder device, and is joined to the opening end at a slight intersection angle in a staggered manner. A flow path switching device for a concrete pump, characterized in that it is formed to