JPS636754B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a switching device for a slurry pump for pumping concrete or similar slurry.

[Conventional technology]

A representative example of a conventional swing type slurry pump switching device for pumping concrete is shown in FIGS. 1 and 2. Two concrete cylinders 1 arranged in parallel have built-in pistons 2 that alternately reciprocate.

Inside the concrete hopper 3, a swing tube 4 is pivotally supported at both ends by bearings 5 and 6. This swing tube 4
is swingably mounted by a hydraulic cylinder 7 so as to be directly connected to the outlet of one of the two concrete cylinders 1.

A seal ring 8 is attached to the entrance of the swing tube 4, and a sliding plate 9 is attached to the outlet side of the concrete cylinder 1 opposite to the seal ring 8.

Figure 3 shows details of the sliding part.

Concrete in the concrete hopper 3 is sucked into the concrete cylinder 1 through an opening in the sliding plate 9 that is not closed by the swing pipe 4. The concrete cylinder 1 on the opposite side is in the discharge stroke, and the concrete pumped by the piston 2 is delivered to the sliding plate 9.
It is sent out into the swing tube 4 through the seal ring 8 and the seal ring 8. Concrete in the swing pipe 4 is discharged into a concrete discharge pipe 10 via a bearing 5.

The sliding plate 9 and the seal ring 8 are replaced when the sliding surfaces become worn, and the seal ring 8 is crimped onto the sliding plate 9 by utilizing the pressure difference between the inside and outside.

[Problem that the invention seeks to solve]

However, in the slurry pump switching device configured in this way, the sliding plate 9 and the seal ring 8 slide against each other when the swing tube 4 is switched, but the sliding surface is covered with aggregate, sand, concrete, etc. intervening, causing local wear.

In order to prevent this, countermeasures have been taken such as installing hard facings on each sliding surface, but this is not sufficient.

In some cases, the seal ring 8 is made to be able to rotate freely, but in many cases, the seal ring 8 becomes immovable due to concrete adhering to the seal ring 8 during use. And seal ring 8 and sliding plate 9
If the relative sliding positions of the parts are fixed, the sliding parts that have a high chance of biting the aggregate will wear out intensively. Therefore, a gap is created locally on the sliding surface of the seal ring 8 or the sliding plate 9. Moisture in the concrete and water during washing may flow out from this gap, causing the concrete to lose its fluidity and causing the concrete pump to lose its function.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a switching device for a slurry pump that eliminates the above-mentioned drawbacks and prevents gaps from forming on the sliding surface due to localized wear and damage on the metallic sliding surface. be.

[Means for solving problems]

A feature of the present invention is that two cylinders that operate alternately are arranged side by side, and a swinging tube connected to the cylinders through a seal ring is alternately connected to the cylinder mouth side of the discharge stroke by a switching means. In the slurry pump configured to be arranged in a switching manner, a concentric land groove is provided on the sliding surface of the seal ring attached to the inlet of the swing tube, and a flexible seal is pressed against the cylinder mouth in the groove. The seal ring is equipped with an elastic body and a flexible seal, and the seal ring is provided with a grease inlet that is inserted into the land groove, and the land groove is filled with grease through the grease inlet.

[Effect]

Since the flexible seal is installed in the land groove, as the seal wears out, the seal is pushed out to be replenished, thereby preventing the generation of gaps on the sliding surface.

Furthermore, since the land groove is filled with grease, concrete can be prevented from entering the land groove, and the seal ring can smoothly move toward the cylinder mouth. Furthermore, when the flexible seal is worn out and the volume within the land groove becomes large, the required amount of grease can be filled from the grease inlet.

〔Example〕

An embodiment in which the present invention is applied to a concrete pump will be described in detail below with reference to the drawings. In FIG. 4, a concrete cylinder 1 is filled with concrete pressurized by a piston, a sliding plate 9, a seal ring 8 It is sent out to the swing tube 4 through. The sliding surfaces of the sliding plate 9 and the seal ring 8 are made of tough, high-hardness metal to resist crushing of aggregates and wear, and the attachment part to the swing tube 4 is the same as the conventional one. .

The flexible seal 10 has a land groove 8a provided on the same circumference approximately at the center of the sliding surface side of the seal ring 8.
located within. The flexible seal 10 is pressed against the sliding plate 9 by a pressure spring 11,
It is made of a flexible and wear-resistant material such as urethane rubber. Grease is filled in the gap around the spring 11 to prevent concrete from entering. If a void occurs, grease inlet 12
Grease is replenished. Grease inlet 12
The lid 13 attached to the container is to prevent concrete from entering.

Next, to explain its function and effect, the swing tube 4 is manufactured and adjusted so that it comes into close contact with the sliding plate 9 as much as possible.
It is inevitable that there will be some gaps due to manufacturing errors. Moreover, this gap tends to increase due to the pressure of concrete pumping, and if aggregate is caught between the sliding surfaces, this gap will further increase.

The sliding surface is worn by the aggregate, but the sliding surface near the line passing through the center of the seal ring 8 and along the swinging direction, where the aggregate is particularly bitten, is locally worn. There is a tendency for the gap between the two to increase. In order to eliminate the above problems, flexible seal 1
0 has the effect of preventing local gaps from increasing due to aggregate encroachment and wear due to the flexibility of the material itself. If the gap between the sliding surfaces increases, the spring 11 pushes the flexible seal 10 onto the sliding surface of the sliding plate 9, thereby preventing the gap from increasing.

Grease is filled in the gap on the back of the flexible seal 10 to prevent concrete from entering. However, when the flexible seal 10 wears out and the gap increases, grease is poured into the gap from the grease inlet 12. Fill it. Further, a lid 13 is provided to prevent concrete from entering through the grease injection port 12.

If the seal ring 8 is forcibly rotatable, the wear of the seal ring 8 and the flexible seal 10 will be uniform over the entire circumference, the life of the flexible seal 10 will be extended, and its effectiveness will further increase.

As described above, according to this embodiment, the flexible seal 1
0 and is pressed by the spring 11 in accordance with the wear of the seal 10, thereby preventing an increase in the gap between the sliding surfaces and preventing difficulty in pumping due to dehydration of poorly mixed concrete and difficulty in pumping water for washing.

Furthermore, since the land groove 8a is filled with grease, concrete can be prevented from entering the land groove 8a, and the flexible seal 10 can smoothly move within the land groove 8a. Further, when the flexible seal 10 is worn and the volume inside the land groove 8a becomes large, the required amount of grease can be filled from the grease injection port 12.

〔Effect of the invention〕

In short, the present invention has two cylinders that operate alternately arranged side by side, and a swinging tube communicated with the cylinders via a seal ring, which is alternately switched and placed on the cylinder mouth side of the discharge stroke by a switching means. In the slurry pump configured as shown in FIG. , a flexible seal, and a grease inlet inserted into the land groove is provided in the seal ring, and the land groove is filled with grease from the grease inlet. Therefore, since the flexible seal is installed in the land groove, it is pushed out by the elastic body so that the seal is replenished as the seal wears out, thereby preventing the generation of gaps on the sliding surface and the leakage from the gaps. Prevents concrete moisture from flowing out and prevents concrete pump performance from deteriorating.

Furthermore, since the land groove is filled with grease, concrete can be prevented from entering the land groove, and the flexible seal can smoothly move within the land groove. Furthermore, when the flexible seal is worn out and the volume within the land groove becomes large, the required amount of grease can be filled from the grease inlet.

[Brief explanation of the drawing]

Figure 1 is a vertical sectional view showing the main parts of a conventional concrete pump, Figure 2 is a schematic diagram of the switching mechanism in Figure 1-, Figure 3 is a sectional view of the main parts of the sliding part, and Figure 4 is FIG. 2 is an enlarged cross-sectional view of a sliding portion showing one embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Concrete cylinder, 2... Piston, 4... Rocking tube, 8... Seal ring, 8a...
... Land groove, 9 ... Sliding plate, 10 ... Flexible seal, 11 ... Spring, 12 ... Grease injection port, 1
3... Lid.

Claims (1)

[Claims] 1. A slurry in which two cylinders that operate alternately are arranged in parallel, and a swinging tube communicated with the cylinders via a seal ring is alternately switched to the cylinder mouth side of the discharge stroke by a switching means. In the pump, a concentric land groove is provided on the sliding surface of the seal ring installed at the inlet of the swing tube, and an elastic body that presses the flexible seal against the cylinder mouth in the groove, and a flexible A switching device for a slurry pump, characterized in that the seal ring is provided with a grease inlet communicating with the land groove, and the land groove is filled with grease from the grease inlet.