JPS6129986Y2 - - Google Patents

Description

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

In a typical configuration of a concrete pump, 180
The suction and discharge ports of the pair of feeding cylinder devices, which are operated alternately with a phase difference of °, face the inside of the ready-mixed concrete input hopper, and a switching passage is formed between the suction and discharge ports and the discharge pipe. By switching the switching passage in synchronization with the reciprocating movement of the piston of the feeding cylinder device, the opening of the feeding cylinder device on the discharge operation side is communicated with the discharge pipe.

Regarding the structure of the flow path switching device that forms this flow path switching passage, various configuration systems have been proposed in the past, but all of the proposed systems have the following common drawbacks. was.

(a) The flow pipe for switching has many non-straight parts such as bent parts, and the cross-sectional area of the flow pipe tends to be uneven in the middle of the flow path, which causes an increase in pressure drop. Inevitable.

(b) Since the non-straight portion of the flow pipe is often moved by a long arm, the switching drive load becomes correspondingly large, and an increase in power capacity is unavoidable.

However, both disadvantages of the lever have become even more pronounced in light of the recent tendency for the quality of ready-mixed concrete to have less lubricity and make it difficult to pump, and the recent importance of energy conservation. It's becoming something big.

The present invention was developed in view of the current situation, and the purpose of the present invention is to provide a flow path switching device for a concrete pump in which the shape of the flow path pipe is close to a straight line and does not have a rotating part. Our goal is to provide the following.

Hereinafter, the present invention will be explained based on an illustrated embodiment.

In the switching device of the embodiment, as shown in FIGS. 1 to 4, on the lower outer surface of one side plate 2a on the right side of the box-shaped hopper 2 installed on the table 1 (FIG. 1), A pair of feed cylinders 3 and 4 installed horizontally side by side have suction and discharge port side ends facing each other, and each feed cylinder 3 and 4 has a half portion inserted into the hopper 2 at the end. Passage tubes 5 and 6 having a conical tip and an opening are fitted onto the outside so that they can roll, that is, rotate reciprocally around their own axes.

Therefore, the feeding cylinders 3, 4 and the passage pipes 5, 6
The overlapping part with the passage pipes 5 and 6 is supported by a bearing on a bracket 7 erected on the frame 1 via a bearing 8 and a ring 9, and the passage pipes 5 and 6 pass through the side plate 2a, and a bearing 8a and a seal ring 8b are connected to each other. It is bearingly supported by the thick wall portion 2b of the side plate 2a through the shaft, and the penetrating portion is sealed.

Next, a mounting block 10 is welded to the outer wall of the intermediate-height end of the side plate 2a, and a drive cylinder device 11 is pivotably supported in the center hole of the mounting block 10.

On the other hand, a collar 5a, which contacts the bracket 7 and receives the thrust acting on each of the passage pipes 5, 6, is provided on the side of the bracket 7 penetrating portion of each passage pipe 5, 6.
6a is formed, and a passive arm 5b, 6b is provided at one location on the outer periphery of each collar 5a, 6a to protrude in the radial direction. Operating rod 12-2
It is pivotally connected to each fork 12a formed at the location with a pin.

Next, the middle of the Y-shaped discharge pipe 13 passes through the center of the lower part of the other side plate 2c of the hopper 2, and the discharge pipe 1
The collar 13a of No. 3 is fixed to the side plate 2c with the sealing material sandwiched therebetween.

By the way, the tips of each of the passage pipes 5 and 6 mentioned above are
The conical surfaces 5c, 6c are formed with passage openings 14, 15 having an oval expanded shape at one location.

On the other hand, each branch pipe 16, 17 of the discharge pipe 13
The diagonally cut-off opening end surfaces 16a, 17a are formed into curved shapes that make sliding contact with the conical surfaces 5c, 6c, and the curved area of the opening end surfaces 16a, 17a is equal to the area covering each passage opening 14, 15. have.

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

First, the pistons 18 of the two feeding cylinders 3 and 4 reciprocate with a phase difference of 180°C, thereby performing the suction and discharge operations of ready-mixed concrete in a staggered manner. Device 1
1, each passage pipe 5, 6 is connected to the operating rod 12.
It is driven by and rotates back and forth.

As a result, each passage opening 14 of both passage pipes 5, 6,
15 communicates with the interior of the hopper 2 at the opposite end, and also communicates with the branch pipes 16 and 17 of the discharge pipe 13 at the opposite end, but the passage opening of the passage pipe in the discharge process communicates with the branch pipe. Since it is assembled into
Each of the feeding cylinders 3 and 4 takes in fresh concrete from the hopper 2 and discharges the fresh concrete into the discharge pipe 13.

However, in the structure of the above-described embodiment, the ready-mixed concrete flow path of "feeding cylinders 3, 4 → passage pipes 5, 6 → discharge pipe 13" is arranged in a substantially straight line, and the area of the flow path is also made almost uniform. Therefore, it does not create a large flow path resistance even for fresh concrete with poor fluidity, and since the only moving parts for switching the flow path are the rolling passage pipes 5 and 6, the switching drive load is low. is extremely small.

As described above, according to the concrete pump flow switching device according to the present invention, the curved passage opening of the cap-shaped passage pipe that is fitted onto each suction/discharge port of a pair of feeding cylinders and rotates back and forth, Since the Y-shaped discharge pipe fixed to the side plate of the hopper is configured to slide into contact with the opening end surface of each branch pipe, it is possible to switch the flow path with low load and large discharge capacity, which improves the pumping operation. This has the effect of providing a pump with excellent switching power reduction.

[Brief explanation of drawings]

FIG. 1 is a plan view of a flow path switching device for a concrete pump showing an embodiment of the present invention, FIG. 2 is a side sectional view taken along the - line in FIG. 1, and FIG. FIG. 4 is a plan cross-sectional view taken along the - line in FIG. 2. 2...Hotsupa, 2a...One side plate, 2c...
The other side plate, 3, 4... Feeding cylinder, 5, 6...
... Passage pipe, 5c, 6c ... Conical surface, 11 ... Drive cylinder as driving means, 13 ... Discharge pipe, 1
4, 15... passage opening, 16, 17... branch pipe,
16a, 17a... cut-off opening end surfaces.

Claims (1)

[Scope of utility model registration request] A hopper into which fresh concrete is introduced, a pair of feeding cylinder devices installed in parallel in opposition to the lower outer surface of one side plate of the hopper, and a pair of feeding cylinder devices that are rotatably fitted into the intake and discharge openings of each of the feeding cylinder devices. a pair of passage pipes, each of which has a passage opening bored at one place on the conical surface of its tip inserted into the hopper; and the above-mentioned feeding cylinder device. a drive means for reciprocating both the passage pipes in synchronization with the reciprocating movement of the piston; and a Y-shaped discharge pipe penetrating through the other side plate of the hopper and fixed to the side plate; The diagonally cut end face of the tip of each branch pipe opening into the pipe slides into contact with the conical surface of each passage pipe, and as the passage pipe rolls, the discharge pipe connected to each passage opening alternately comes into contact with the conical surface of each passage pipe. A flow path switching device for a concrete pump, characterized in that: