JPS61271014A - Fixing device for filter - Google Patents

Abstract

PURPOSE:To obtain a filter prevented from leakage of air through a gasket by providing a continuous linear projection on the upper face of a filter receiver confronting the rear face of a filter frame. CONSTITUTION:A continuous linear projection 4a is formed by bending upward whole periphery of an internal peripheral edge of a filter receiver 4 which is stretched from an inside wall face of an external sheathing 3 to enclose a filter. When a filter frame 1 is clamped interposing a keeping fitting 7 by turning a nut, pressure is applied to a gasket 7 by a tip end of the linear projection 4a. Since the clamping force is concentrated to the tip end of the linear projection 4a, the gasket 8 is pressed sufficiently. Further, the rigidity of the filter receiver 4 is increased because the internal peripheral edge of the filter receiver is bent, and almost equal pressure can be exerted to the whole periphery of the linear projection 4a when the nut 6 is clamped.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a filter fixing device for creating a dust-free space necessary for semiconductor manufacturing and the like.

(Prior Art) A conventional filter fixing device will be explained with reference to FIGS. 5 and 6. 5 and 6 are a side sectional view and a plan view, respectively, of the filter fixing device. Although the filter 2 attached to the filter frame 1 is depicted in FIG. 5, it is omitted in FIG. It is.

In FIG. 5, the conventional filter fixing device has an exterior body 3.
The filter receiver 4 is rotated so as to protrude from the inner wall surface of the filter receiver 4, and the plurality of bolts fixed perpendicularly to the upper surface of the filter receiver 4 are attached using bolts 5, nuts 6 that fit into the bolts, and filter 2.
and a presser metal fitting 7 for holding down the filter frame 1 to which the filter frame 1 is attached.

The packing 8 is inserted between the lower surface of the filter frame 1 and the filter receiver 4, and the above-mentioned installation is carried out by applying the presser fitting 7 inserted through the bolt 5 to the upper surface of the filter frame 1, tightening the nut 6, and tightening the filter 2. is fixed to the exterior body 3. Note that the arrows in the figure indicate the flow of air.

FIG. 6 is a plan view of the filter fixing device shown in FIG. 5, in which two bolts 5 are fixed on each side of the filter receiver 4 extending from the inner wall of the exterior body 3.
A presser metal fitting 7 is inserted into each bolt 5, and a nut 6 is fitted onto the metal fitting 7.

(Problems to be Solved by the Invention) In such a configuration, when the nut 6 is turned and the filter holding fitting 7 is tightened downward, the filter frame 1 and the filter receiver 4 are each flat, and the structure is such that the packing 8 is tightened. Therefore, there was a problem in that the rigidity of the filter receiver 4 was insufficient, and sufficient compressive force could not be applied to the entire surface of the gasket 8, causing air leakage from the gasket 8.

Furthermore, if there are variations in the tightening of the nut 6, there is a problem in that the packing 8 is not compressed uniformly and air leaks from locations where the compression rate is low.

The present invention aims to solve these problems and provides a filter fixing device that does not cause air leakage from the packing.

(Problems to be Solved by the Invention) In order to solve the above-mentioned problems, one aspect of the present invention is to provide a continuous linear protrusion on the upper surface of the filter holder that faces the lower surface of the filter frame.

(Function) With this configuration, the rigidity of the filter holder is increased, and when the nut is tightened, the tightening force is evenly distributed over the linear protrusions, and is concentrated on the tip of the nut. A uniform and sufficient compressive force is applied to the entire circumference of the packing, and the packing is completely brought into close contact between the filter frame and the filter receiver.

As a result, even if the tightening torque varies, the seal is sufficiently compressed and no air leakage occurs.

(Example) A first example of the present invention will be described with reference to FIGS. 1 to 3, and a second example will be described with reference to FIG. 4.

1, 2, and 3 are a side sectional view, an enlarged sectional view of important parts, and a plan view of the first embodiment, respectively.
Although the filter 2 attached to the filter frame 1 is depicted in the figure and FIG. 2, it is omitted in FIG. 3. Fourth
The figure is an enlarged sectional view of the main part of the second embodiment.

In the filter fixing device according to the present invention shown in FIG. 1, the inner circumferential end of the filter receiver 4, which is rotated so as to protrude from the inner wall surface of the exterior body 3, is bent upward over the entire circumference to form a continuous linear protrusion 4a. The structure is the same as the conventional example shown in FIG. 5 except that . Further, as shown in FIG. 3, an L-shaped guide fitting 9 is fixed to the upper surface of the filter receiver 4 at approximately the center of each inner wall surface of the exterior body 3, and as shown in the enlarged cross-sectional view of FIG. In addition, the structure is such that the position of the filter 2 is accurately determined with a small gap between the outer periphery of the filter frame 1 and the filter frame 1.

In such a configuration, when the nut 6 is turned and the filter frame 1 is tightened via the presser fitting 7, continuous linear protrusions 4a on the lower surface of the filter frame 1 and the inner circumferential upper surface of the filter receiver 4 are removed.
Pressure is applied to the packing 8 between the tips of the . At this time, since the tightening force is concentrated on the tip of the linear protrusion 4a, the gasket 8 is sufficiently compressed.

Furthermore, since the inner peripheral end of the filter receiver 4 is bent, its rigidity is increased, and when the nut 6 is tightened, a substantially uniform compressive force is applied over the entire circumference of the linear protrusion 4a.

As a result, air leakage caused by insufficient compression of the packing 8 can be eliminated. Furthermore, in this embodiment, since the guide fitting 9 is provided, the filter 2 is placed on the filter receiver 4 so that the tip of the linear protrusion 4a of the filter receiver 4 is always in the center of the width of the packing 8. Attach.

Next, a second embodiment will be explained with reference to FIG. In the second embodiment, on a filter receiver 4 whose inner peripheral end is bent to form a continuous linear protrusion 4a, a cross-sectional crosspiece 10 is fixed at a position opposite to the lower surface of the filter frame 1, This forms the second linear protrusion 10a.

In such a configuration, the rigidity of the filter receiver 4 is further increased, and the double linear protrusions 4a and 10a compress the packing 8 at two locations, so that the air leak prevention performance is further improved.

(Effects of the Invention) As explained above, by forming continuous linear protrusions on the upper surface of the filter holder that faces the lower surface of the filter frame, the rigidity of the filter holder is improved, and the filter frame and the filter holder are The tightening force of the nut concentrates on the tip of the continuous linear protrusion of the filter holder and presses the packing strongly, and the linear protrusion sinks into the packing, making it difficult to tighten the nut. Even if there are variations in the air, there will be no air leakage from the packing.
A highly reliable filter fixing device is obtained.

[Brief explanation of drawings]

1, 2, and 3 are a side cross-sectional view, an enlarged cross-sectional view of essential parts, and a plan view excluding the filter, respectively, of a first embodiment of the filter fixing device according to the present invention, and FIG. The enlarged sectional view of the main part of the second embodiment, FIG. 5, and FIG. 6 are respectively a side sectional view of a conventional filter fixing device and a plan view showing the filter. 1... Filter frame, 2... Filter,
3...Exterior body, 4...Filter receiver, 4a.
...Continuous linear protrusion, 5...Mounting with bolts, 6
... Nut, 7 ... Holding metal fitting, 8 ... Packing metal fitting, 9 ... Guide metal fitting, 10 ... Cross section cross-section crosspiece, 1
0a...Continuous linear protrusion.

Claims (1)

[Claims] The filter is fixed using a filter fixing device consisting of a filter receiver protruding from the inner wall of the exterior body, multiple mounting bolts planted in the filter receiver, multiple holding fittings inserted through these, and nuts that tighten these. A filter fixing device characterized in that a continuous linear protrusion is provided on the upper surface of the filter receiver that faces the lower surface of the filter frame to which the filter is attached.