JPH0754769A - Swing valve for concrete pump - Google Patents

Abstract

PURPOSE:To prevent uneven wearing between a sliding plate provided in a hopper and a valve ring provided in a rocking pipe rocked on the sliding plate. CONSTITUTION:A valve ring 7 provided in the point end of a rocking pipe 6, right/left rocked in a hopper 1, is slid on a sliding plate 11 fixed in the hopper 1 of opening a pair of right/left suction/delivery ports 2. An aggregate coming off part, formed of grooves or notches, is formed in a part surrounded by external edges of a pair of the right/left suction/delivery ports 2, 2 of the sliding plate 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a swing valve for a concrete pump.

[0002]

2. Description of the Related Art An example of a conventional concrete pump having a swing valve will be described with reference to FIG. 2. A pair of suction / discharge ports 2 are provided side by side on the lower front portion of a hopper 1, and outside the hopper 1. Corresponding to the above two suction / discharge ports 2,
Two concrete cylinders 3 are installed in parallel, concrete pistons 4 housed in the concrete cylinders 3 are integrally connected via a piston rod 5 of a hydraulic cylinder (not shown), and the pistons 4 are moved back and forth by the hydraulic cylinders. . At the opening of the suction / discharge port 2 with the hopper 1, a slide plate 11 having the suction / discharge port 2 is attached to the hopper 1 so as to be replaceable by bolt connection or the like.

On the other hand, a bent oscillating tube 6 is positioned in the hopper 1, and a valve ring 7 is attached to the tip of the oscillating tube 6 in a replaceable manner, and alternates with two suction / discharge ports 2. In order to be able to match with, the sliding plate 11 is pressed and swings. The other end of the rocking tube 6 is connected to the transport pipe by penetrating the back surface of the hopper 1, and the other end of the rocking shaft 8 fixed in the middle of the rocking tube 6 is penetrated into the front wall of the hopper 1, The swing shaft 8 is connected to the operation lever 9 outside of the unit 1, and the operation lever 9 is swung by a drive device (not shown)
The oscillating tube 6 oscillates leftward and rightward around the oscillating shaft 8 via the.

When the concrete in the hopper 1 is sucked and discharged by the concrete pump, the rocking pipe 6 is rocked so as to be positioned at either one of the suction and discharge ports 2, and the inside of the cylinder 3 is concerned. The piston 4 moves forward and discharges the concrete that has been sucked up to now through the inside of the rocking pipe 6. Further, in another cylinder 3, the piston 4 retracts and sucks the concrete in the hopper 1. These processes are repeated by rocking the rocking pipe 6 to suck and discharge concrete.

[0005]

In the concrete in the hopper of the concrete pump described above, the valve ring 7 attached to the rocking pipe 6 is pressed against the sliding plate 11 and slides. The sliding surface of the sliding plate 11 in this case is shown in FIG.
As shown in Fig. 3 (b) and Fig. 3 (b), the sliding surface of the valve ring 7 is worn by the inclusion of aggregate, but the sliding surface is worn evenly. Instead, a part with much wear and a part with little wear occur.

In FIG. 3, upper and lower side surfaces A and B of the valve ring 7 and a pair of left and right inlet / outlet ports 2 of the sliding plate 11
A ', B'parts surrounded by the outer edge of the valve ring are often worn, and the left and right side surfaces C, C of the valve ring 7 and the sliding plate 11 are sucked and sucked.
The portion C'between the discharge ports 2 and 2 and the left and right outer edges C ', C'
The part has little wear. The reason why such uneven wear occurs is that the aggregate caught between the C ′ portion where the sliding plate 11 is less worn and the C portion where the valve ring 7 is less worn passes through the suction / discharge port 2. At this time, the sliding surfaces fall off into the suction / discharge port 2 so that the wear due to the aggregate is relatively small, while the sliding plate 11 has a large amount of wear, and the A ′ and B ′ parts and the valve ring. Since the aggregate that is bitten between A and B, which has a large amount of wear, does not easily fall off because the mating surface is always present, both sliding surfaces are subject to large grinding wear and This is because the aggregate that is embedded in the surface acts as a cutting tool and causes the other material to grind and wear violently.

In this way, the wear of the A, A'parts, B, B'parts is relatively greater than the wear of the C, C'parts. As a result, in the discharge process of concrete, a clearance is generated at the mating surface of the sliding plate 11 and the valve ring 7, high-pressure concrete leaks from the mating surface, and the efficiency of the pump deteriorates. And the valve ring 7 must be replaced early.
In order to extend the life of the sliding plate and the valve ring, generally expensive cemented carbide is used, or wear resistant surface treatment is used.

The present invention provides a sliding plate shape which prolongs the replacement life of the sliding plate 11 and the valve ring 7 without using an expensive wear resistant material.

[0009]

The structure of the present invention for achieving the above object will be described with reference to FIGS. 1 and 2 corresponding to the embodiments. A valve plate 7 provided at the end of the moving tube 6 is fixed to a sliding plate 11 fixed in a hopper 1 which opens a pair of left and right inlet / outlet ports 2.
In a rocking valve of a concrete pump that slides up, aggregates formed by grooves or notches are dropped in a portion surrounded by outer edges of the pair of left and right suction / discharge ports 2 and 2 of the sliding plate 11. It is characterized in that the portion 12 is formed.

[0010]

In the present invention, A ', B'surrounded by the outer edges of the pair of left and right suction / discharge ports 2 of the sliding plate 11 by the above means.
Aggregates that have been bitten into the A'and B'parts of the sliding plate 11 and the upper and lower side surfaces A and B of the valve ring 7 are dropped into the dropout part 12 of the aggregate formed in the part. In this way, since there is a fall-off process of the aggregate similar to the C'part / C part, A '
The wear of the part / A part and the B ′ part / B part is about the same as the wear of the C ′ part / C part. That is, the sliding surface of the sliding plate 11 and the sliding surface of the valve ring 7 have uniform wear with a small difference in the degree of wear, leakage of concrete is reduced in the discharge process, and the replacement life is improved.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIG. 1. Reference numeral 11 denotes a sliding plate, and a pair of left and right inlet / outlet ports 2 are opened in the sliding plate 11 and the left and right sides are formed. Aggregate dropout portions 12 composed of grooves or notches were formed in the portions A ′ and B ′ surrounded by the outer edges of the pair of suction / discharge ports 2 and 2.
In the figure, the broken line indicates the phase boundary line of the wear boundary between the valve ring 7 and the sliding plate 11.

[0012]

As described above, according to the present invention, the sliding plate fixed in the hopper that opens the left and right pair of suction / discharge ports is surrounded by the outer edges of the pair of left and right suction / discharge ports. Since the aggregate dropout part consisting of a groove or a notch is formed in the part, by sliding between the sliding plate and the valve ring,
The aggregate that has been bitten into the valve ring and the part surrounded by the outer edges of the pair of left and right inlet / outlet ports falls off from the aggregate drop-out part, so that the wear of that part is the side face of the inlet / outlet ports. Since a clearance due to uneven wear is less likely to occur on the contact surface, the amount of leakage from the mating surface of the sliding plate of high-pressure concrete and the valve ring is reduced during the discharge process, resulting in a longer life.

[Brief description of drawings]

FIG. 1 is a plan view of a sliding plate and a valve ring according to an embodiment of the present invention.

FIG. 2 is a side sectional view of a conventional concrete pump.

FIG. 3 is a plan view showing a worn state of a conventional sliding plate and a valve ring.

[Explanation of symbols]

 1 Hopper 2 Suction / Discharge Port 6 Oscillating Tube 7 Valve Ring 11 Sliding Plate 12 Falling Part

Claims (1)

[Claims] 1. A valve ring provided at the tip of a rocking tube that rocks left and right in a hopper slides on a fixed sliding plate in a hopper that opens a pair of left and right inlet and outlet ports. In the swing valve of the concrete pump, the sliding plate,
In the part surrounded by the outer edges of the pair of left and right suction / discharge ports,
An oscillating valve for a concrete pump, characterized in that an aggregate dropout portion formed of a groove or a notch is formed.