JPH0251127B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for manufacturing a sealed container suitable for, for example, an electronic water meter.

[Technical background of the invention and its problems]

BACKGROUND ART Recently, water meters with electronic gear mechanisms for detecting water volume have become popular. In other words, this water meter has the function of non-contactly detecting the impeller rotating with the amount of water used, electrically integrating and displaying the integrated value, and transmitting the integrated value to the outside in a predetermined message format. have. Therefore, compared to the above-mentioned mechanical water meter having a conventional gear mechanism,
In addition to improving aging characteristics and sensitivity, the failure rate can also be significantly reduced. By the way, computerized water meters have high-density electronic components such as LSI built-in, and must be used to measure water over a long period of time (several years), so a high level of airtightness is required. . However, in mechanical water meters, sealing is usually performed by tightening screws with O-rings in between, but the sealing method applied to such mechanical water meters has changed due to electronic technology. It is not possible to achieve the high airtightness required for water meters. Therefore, some attempts have been made to seal containers for water meters by cold pressure welding. In this sealing method using cold pressure welding, the thickness of the container must be reduced in order to obtain good bonding properties. However, as the thickness of the container decreases, its mechanical strength decreases significantly and it becomes unable to withstand external pressure such as water hammer. Therefore,
A method has been adopted in which a thin-walled inner container suitable for cold welding that houses electronic components is housed in a thick-walled outer container, and the inner container is protected from external pressure by the outer container. However, such a double-walled container requires a large number of parts and a complicated processing process, so there has been a demand for rationalization.

[Purpose of the invention]

The present invention has been made in consideration of the above circumstances, and is a method for manufacturing a sealed container such as an electronic water meter, which has a simple structure, is strong, and can be easily cold-welded. The purpose is to provide

[Summary of the invention]

When producing a sealed container by providing a flange protruding from the opening of the casing, overlapping the flange of the lid with this flange, and cold-pressing the pair of overlapping flange parts, The flange of the casing and/or the flange of the lid are formed into a stepped shape with a thick wall on the main body side and a thin wall on the outside, and the parts formed on the thin wall are cold pressure welded. It was designed to do so.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows the structure of a sealed container for an electronic water meter manufactured in this example. At the center of the bottom of the bottomed cylindrical storage body 1, there is a storage body 1.
A recessed portion 2 having a coaxial cylindrical shape is provided. A tip end of a rotating shaft 4 of an impeller 3, which is supported by a bearing (not shown), is loosely fitted into the recessed portion 2. Further, the wall thickness of the storage body 1 is formed to have a mechanical strength capable of withstanding external pressure such as water hammer. Thus, the opening edge of the storage body 1 is provided with a flange 5 that projects outward. The opening of the storage body 1 is then closed by the lid 6.
This lid body 6 includes a metal annular part 8 with a circular hole 7 bored in the center thereof, and a transparent glass disc 9 sealed with glass inside the annular part 8 to close the circular hole 7. It is made up of. Furthermore, a flange portion 10 into which the flange portion 5 is fitted is provided protruding from the side edge of the lower end of the annular portion 8 . Then, inside the storage body 1, printed circuit boards 11, 11 on which various electronic components are mounted and lithium batteries 12, 12 are stored at predetermined positions. Thus, the sealed container configured as described above is fastened and fixed to the cylindrical outer frame 13. This outer frame 13 is connected to, for example, a water pipe. And outer frame 1
An O-ring 14, which is an elastic ring with a circular cross section, is inserted between the stepped portion 13a provided on the inner circumferential surface of 3 and the flange 5, and the sealing action of this O-ring 14 prevents water from leaking to the outside. It is becoming more and more common.

Next, a method for manufacturing the sealed container having the above structure will be described. First, the storage body 1 and the lid body 6 are formed by press working. At this time, the annular flange 5 formed on the storage body 1 has a stepped structure consisting of an inner thick part 5a and an outer thin part 5b, as shown in FIG. The thin portion 5b is pressed to have a thickness of 1 mm or less so that it is suitable for cold welding. Further, the thick portion 5a is press-formed to have a thickness of 5 mm or more in order to have sufficient mechanical strength to withstand the fastening force described below. On the other hand, an annular flange 10 formed on the lid 6
is press-molded so as to fit into the flange 5 of the storage body 1. Among the flanges 10, the thin portions 5 of the flanges 5
The thickness of the part that contacts b is press-formed to a thickness of 1 mm or less to make it suitable for cold pressure welding. The thickness of the portion of the flange portion 10 that contacts the portion other than the thin portion 5b may be press-molded to any thickness within a range that does not impair mechanical strength. Then, electronic components such as printed circuit boards 11, 11, lithium batteries 12, 12, etc. are mounted in predetermined positions inside the housing 1, and predetermined wiring work is performed. Next, cover the opening of the storage body 1 with the lid 6, and close the flange 5.
and the flange 10 are fitted and brought into close contact with each other. Thus, the third
As shown in the figure, the thin wall portion 5b of the collar portion 5 and the collar portion 10 overlaid on the thin wall portion 5b are cold pressure welded to seal the storage body 1 with the lid body 6. After cold welding, an annular recess 15 is formed. Then, this sealed container is fitted into the outer frame 13 and fastened to the outer frame 13 using, for example, screws. At this time, an O-ring 1 is inserted between the stepped portion 13a and the thick portion 5a of the flange portion 5.
4 is inserted to seal the inside of the outer frame 13 filled with water. As the sealed container is fastened to the outer frame 13, the flange 5 is subjected to strong pressure. However, since the part to which this pressure is directly applied is the thick part 5a, it will not be deformed.

In the above embodiment, the interface between the thick part 5a and the thin part 5b is an upright surface, but it may be a tapered surface 16 as shown in FIG.
As shown in the figure, an R-shaped stepped surface 17 may be used. Furthermore, as shown in FIG. 6, a step may be formed on the opposite side of the flange 5 from the lid 6, consisting of a thick part 5a and a thin part 5b. In this case, the flange 10 may have a planar shape, which has the advantage of being simple in shape. Further, in FIG. 2 of the above embodiment, the wall thickness of the collar portion 10 is uniform, but the portion of the collar portion 5 facing the thick wall portion 5a may be made into a thick wall portion.

〔Effect of the invention〕

In the method for manufacturing a sealed container of the present invention, the flange of the sealed container to be cold welded is formed into a stepped shape with a thick wall part on the inside and a thin wall part on the outside, and only the thin wall part is cold welded. As a result, the cold weldability is improved due to the thin walled portion, and as a result, the container is completely sealed. Furthermore, there is an advantage that the thick part of the flange can be used to engage and fasten other parts of the sealed container without causing deformation of the flange.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a sealed container manufactured in an embodiment of the present invention, FIG. 2 is a sectional view of the flange of the sealed container shown in FIG. 1 before cold welding, and FIG. 3 is the same as that shown in FIG. The illustrated sectional view of the flange after cold welding and FIGS. 4 to 6 are sectional views showing various step structures of the flange before cold welding in other embodiments of the present invention. 1: Storage body (casing), 5: Flange part, 5a: Thick wall part,
5b: Thin wall portion, 6: Lid body, 10: Flange portion.

Claims (1)

[Claims] 1 A flange is provided protruding from the opening of the casing, the flange of the lid is overlapped with the flange of the casing, and the pair of overlapping flange parts are cold-welded to form the casing and the lid. In the method for manufacturing a sealed container, the flange of the casing and/or the flange of the lid are formed with a thick part on the inside and a thin part on the outside, 1. A method for manufacturing a sealed container, comprising cold pressure welding a portion formed in the above.