JPH0565183U - Display tube surface filter waterproof mounting structure - Google Patents

Abstract

(57) [Summary] [Purpose] When waterproofing a filter that covers the surface of a display tube such as a cathode ray tube, the purpose is to eliminate the waterproof failure that accompanies the tightening of mounting screws. [Structure] Inner surface 1A around the opening 1 on the front surface side of the casing
In addition, the groove 2 opening to the casing surface side is formed integrally around the entire circumference, and the peripheral wall 2A on the inner surface side of the casing opening 1 of the groove 2 is higher than the outer peripheral wall 2B so as to receive the thickness of the filter 3. The size of the filter 3 is small and covers the casing opening 1 in which the elastic packing 4 having a U-shaped cross section is fitted to the outer periphery 3A. And further, elastic packing 4
The filter 3 is elastically supported by a claw-shaped projection 4B that is provided so as to project on the outer circumferential surface 4A and is compressed on the inner surface of the groove outer circumferential wall 2B.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 This invention relates to a waterproof mounting structure for a display tube surface filter.

[0002]

[Prior Art]

 Conventionally, for example, the display tube part of an electronic instrument that has a display tube such as a navigation device such as a fish finder, radar, loran, etc., covers the display tube surface in order to protect the inside of the casing from dew condensation, rainwater or seawater splashing. A waterproof structure is used around the filter.

As this waterproof structure, conventionally, for example, as shown in FIG. 3, a stepped receiving portion A is formed around an opening C ′ of a casing C, and an elastic packing P is inserted into the receiving portion A to filter the filter. It is practiced to apply F and fix the four corners with screws B ... B as shown in FIG.

[0004]

[Problems of conventional technology]

 However, in the case of the waterproof mounting structure described above, when the screws B ... B are tightened strongly, the repulsive elastic force of the elastic packing P causes the center portion M of the filter F to bend, resulting in incomplete waterproofing. Moreover, since the worker tries to complete the installation, he is likely to tighten the screws more than necessary, which further facilitates the above defects.

[0005]

[Problems to be solved by the device]

 The present invention has been made in view of the above problems, and an object thereof is to provide a waterproof mounting structure for a display tube surface filter which can be easily mounted and can be completely waterproofed.

[0006]

[Means for Solving the Problems] That is, the waterproof mounting structure for a display tube surface filter of the present invention is a groove for opening to the casing surface side on the inner surface of the casing surface side opening for housing a display tube such as a cathode ray tube. Are formed integrally around the entire circumference, and the peripheral wall on the inner surface side of the casing opening of the groove is lower in height than the outer peripheral wall so that the thickness of the filter can be received. A filter having a size that covers the casing opening in which the elastic packing that forms the elastic packing is fitted and abuts the elastic packing in the groove, and further projects from the outer circumferential surface of the elastic packing, and The filter is elastically supported by a claw-shaped projection that is compressed on the inner surface of the groove outer peripheral wall.

[0007]

【Example】

 Next, an embodiment of this invention will be described. 1 is a sectional view of an essential part of an embodiment of the present invention, and FIG. 2 is a sectional view of another embodiment.

The waterproof mounting structure of the display tube surface filter according to the present invention has a groove 2 that opens to the casing surface side on the entire inner circumference of the inner surface 1A of the surface side opening 1 of the casing that houses the display tube X such as a cathode ray tube. The peripheral wall 2A on the inner surface side of the casing opening 1 of the groove 2 is formed lower than the outer peripheral wall 2B so as to receive the thickness of the filter 3, and the outer peripheral surface 3A has a U-shaped cross section. A filter 3 having a size to cover the casing opening 1 in which the elastic packing 4 forming the above is fitted is abutted by accommodating the elastic packing 4 in the groove 2 and further protruding to the outer circumferential surface 4A of the elastic packing 4. The filter 3 is elastically supported by a claw-shaped projection 4B which is provided and compressed on the inner surface of the groove outer peripheral wall 2B.

In the above embodiment, if the circumference of the elastic packing 4 is made shorter than the outer circumference of the filter 3, the elastic packing 4 tightens the outer circumference of the filter 3 with its elastic contraction force, which is convenient because it does not come off easily. Also, if the corners of the claw-shaped projections 4B formed on the outer circumference of the elastic packing 4 are rounded as shown in the figure, it is convenient because the insertion is easy and the escape after insertion can be prevented. Further, if the elastic packing 4 has a symmetrical cross-section as shown in the drawing, the workability is improved because there is no restriction on the orientation when the elastic packing 4 is attached to the filter 3.

As the above-mentioned embodiment, the case of a simple waterproof structure is shown. However, when the filter 3 needs to be shielded, it extends to the inside of the casing opening 1 on the peripheral wall 2A of the groove 2 as shown in FIG. A protruding flange portion 2C is formed, and a nut 5 serving as a ground terminal is embedded and fixed therein, and the filter 3 is attached to the nut 5 via a screw 6. Note that 3G indicates a conductive surface laminated on the filter 3.

[0011]

[Action]

 In the filter 3, the gap S is waterproofed by fitting the elastic packing 4 fitted to the outer periphery thereof. Further, waterproofing between the packing 4 and the casing opening 1 is performed by compression insertion of the claw-shaped projection 4B. Further, since the packing 4 is attached in a state of being housed in the groove 2, the filter 3 is prevented from protruding more than necessary to the front surface side, and a stable attachment state is achieved.

[0012]

[Effect of the device]

 As described above, this invention waterproofs the surroundings by compression-inserting the elastic packing 4 fitted around the filter 3, so that the entire circumference is uniformly waterproofed and the intrusion of water drops is surely prevented, and the screw It is possible to surely prevent the waterproof failure due to excessive tightening. If the circumference of the elastic packing 4 is made shorter than the outer circumference of the filter 3, the elasticity between the filter 3 and the elastic packing 4 ensures the waterproofness between the filter 3 and the elastic packing 4, so that the waterproof effect is further improved. is there.

[Brief description of drawings]

FIG. 1 is an enlarged sectional view of an essential part of an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of a main part of another embodiment.

FIG. 3 is an enlarged cross-sectional view of a main part of a conventional example.

FIG. 4 is a perspective view of essential parts showing a mounted state of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Front surface side opening part of casing 1A ... Inner peripheral surface 2 ... Groove 2A ... Groove inner surface side peripheral wall 2B ... Groove outer surface side peripheral wall 3 ... Filter 3A ... Filter outer circumference 4 ... Elastic packing 4A ... Circumferential outer surface 4B of elastic packing ... Claw projection

Claims (1)

[Scope of utility model registration request] 1. A groove 2 opening to the casing surface side is integrally formed on a peripheral inner surface 1A of a casing surface side opening 1 for accommodating a display tube X such as a cathode ray tube.
The peripheral wall 2A of the groove 2 on the inner surface side of the casing opening has a height lower than that of the outer peripheral wall 2B so as to receive the thickness of the filter 3, and an elastic packing 4 having a U-shaped cross section is formed on the outer periphery. A filter 3 having a size to cover the fitted casing opening is housed in the groove 2 and brought into contact with the elastic packing 4, and further provided on the outer circumferential surface 4A of the elastic packing 4 in a protruding manner. A waterproof mounting structure for a display tube surface filter, wherein the filter 3 is elastically supported by a claw-shaped projection 4B that is compressed on the inner surface of the groove outer peripheral wall.