JPS60252Y2 - Soft skirt for vacuum brick forming equipment - Google Patents

Description

[Detailed description of the invention] The applicant filed a patent application for a vacuum brick forming device related to the invention with Patent Application No. 55-67396 (Japanese Unexamined Patent Publication No. 162607-1981) dated May 2, 1933. In the above invention, the present application has determined a specific new structure for the upper and lower soft skirts that play the role of elastically sealing the vacuum chamber.

The performance required of a soft skirt is, firstly, to withstand over 1,000,000 repeated expansion and contraction strokes, secondly, to maintain a secure connection with the sealing annular fitting in order to keep the vacuum chamber airtight. Thirdly, the telescopic stroke is large and the closed volume during contraction is minimal.

Among these, the applicant came up with the idea that the most important conditions were that the expansion and contraction stroke be large and the sealed volume during contraction be minimized, and in order to satisfy these conditions, the structure of the donut-shaped soft skirt as shown in the figure was realized. .

The key point is that the wall of the soft skirt facing the vacuum chamber is made into an arc-shaped concave surface, and by making the concavity large, its range of motion is widened, and it does not exert large cross-bending stress on the soft material. It also deforms very naturally in response to external pressure.

The lower part of the mold usually has less range of motion than the upper part, but even if the skirt does not move, this construction requires the least vertical space and therefore reduces the height of the machine. .

Now, to explain its structure, as shown in Figures 1 and 2, the soft skirt related to the present application has two rings 1 and 2 inside and outside.
The rectangular cross section and the circular concave wall 3 between the circular rings are integrally formed using a stretchable elastic material such as rubber (reinforced if necessary).

The arc-shaped concave wall 3 has both sides curved at right angles to the rectangular cross sections of the two inner and outer rings as shown in Figure 3, and when the vacuum chamber is sealed, the concave side faces the atmosphere. shall be.

Next, how to use the flange 4 is to lower the flange 4 in the direction of the arrow from the position shown in FIG. to create a vacuum.

Next, as shown in C, the plunger 7 is pushed down to pressurize the raw material 8 in the mold, and this process is repeated until the predetermined pressurization is completed, and the flange 4 is raised to return to the position A. .

Needless to say, the lower surface of the mold 5 is also sealed in the same manner.

In the above order, the volume of the vacuum chamber during pressurization as shown in Figure C is the smallest, so the air extraction effect is maximized.

Furthermore, since the movement of the recess from A to the mouth is arcuate, the deformation of the recess in C in response to atmospheric pressure is flexible, and no one can deny that the stress it receives is completely reasonable.

One more important thing is that the flange 4 and plunger 7
The airtightness of the vacuum chamber is almost completely maintained by tightly clamping the rectangular cross-sections on both sides of the arc-shaped concave wall against the hard side surfaces by the presser ring 9.

In short, the deformation under stress is extremely natural and the airtightness is maintained to a degree that cannot be expected with conventional soft skirts, and I am convinced that its practical benefits are enormous.

[Brief explanation of drawings]

1 and 2 are a vertical cross-sectional view and a plan view of a soft skirt according to the present invention, and FIG. 3 is an enlarged cross-sectional view of the section 1--2 in FIG. 2. Figure 4 A 9 mouth. C is an explanatory diagram of its use. 1... Inner ring, 2... Outer ring, 3...
... Concave wall, 4 ... Flange, 5 ... Mold, 6 ... Sealed chamber, 7 ... Plunger, 8 ... Raw material, 9...presser ring.

Claims (1)

[Scope of utility model registration request] In a vacuum brick forming machine, an arc-shaped concave wall with both sides of the wall of the same material curved perpendicular to the ring wall is integrally formed between two rings with a rectangular cross section made of a flexible soft material such as rubber. ,
A soft skirt characterized in that both sides of the concave wall have a structure that allows relative movement in the vertical direction between the two inner and outer rings, and the concave wall is such that the concave surface necessary for sealing faces the atmosphere side.