JPS62235Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is designed to prevent water from entering the inside of the electric meter by interposing an elastic body between the case and the cover, especially in relatively small electric meters such as electric indicating meters or electronic meters. This invention relates to a waterproof device that can prevent the above.

An example of an electric meter that requires a waterproof device is a level meter for a gas bath installed in a melting chamber, and conventionally, this type of waterproof device has a configuration as shown in FIG. 1.

The structure of the case and the cover used here, or the elastic body fitted between them, is shaped as shown in FIGS. 2 and 3.

That is, in the figure, reference numeral 1 denotes an internal element constituting an electric meter, which is equipped with a pointer for indicating. 2 is a case made of an insulating material and to which the internal element 1 is attached; 3 is a scale plate; 4 is a cover made of an insulating material that protects the scale plate 3 and is the surface of the internal element 1; 5 is a case 2 and a cover made of an insulating material; An elastic body such as rubber is fitted between the case 2 and the cover 4, and 6 is a set screw that fixes the case 2 and the cover 4 together.

As shown in detail in Fig. 2, a groove-like recess 2b is formed in the joint surface 2a of the case 2 with the cover 4 along the extending direction. The cross-sectional shape of the conventional elastic body 5 includes a circular shape, a U-shape, and a flat plate shape as shown in Figs. 3a to 3c. The elastic body 5 having these cross-sectional shapes is attached to the case 2 as shown in Figs. 2a to 2c.
On the other hand, the cover 4 has a convex pressing portion 4b formed on a joining surface 4a that joins with the joining surface 2a of the case 2, and the pressing portion 4b is pressed against the elastic bodies 5a, 5b, 5c that are fitted into the recesses of the case 2.
2(d) to 2(f), the cover 3 is attached to the case 2 to provide a waterproofing.

However, conventional waterproofing devices of this type have had various drawbacks as described below.

When molding a circular elastic body 5 as shown in FIG. It was necessary to perform a positioning operation.
Furthermore, when molding an elastic body 5a having a circular cross section as shown in FIG. 3a, when two semicircular molds are removed, burrs 7 are formed as shown in FIG.
This caused the burrs 7 to float, making it difficult to remove them. Also, when molding the U-shaped elastic body 5b as shown in FIG. 3b, a mold with a U-shaped recess and a mold with a projection that fits into the recess of this mold are required. Also, during molding, it was necessary to perform a positioning operation so that the convex part of one mold fits into the concave part of the other mold. In this way, when molding the elastic bodies 5a and 5b having cross-sectional shapes as shown in FIGS. 3a and 3b, it is essential to position the two molds, which makes the molding work cumbersome and expensive. There were flaws.

Next, when molding the flat elastic body 5c shown in FIG. The elastic body 5c is the second
As shown in FIG. cover 4.
When pressed by the pressing part 4b of the elastic body 5
Since the amount of deformation c is extremely small, a large pressing force is naturally required. Therefore, if this pressing force is insufficient, it is difficult to effectively prevent water from entering the inside of the cover 4 and case 2 from the outside through the part where the pressing part 4b of the cover 4 presses against the elastic body 5c. However, in some cases, there is a possibility that a gap may be formed between the joint surface 2a of the case 2 and the joint surface 4a of the cover 4, resulting in a drawback that a sufficient waterproof effect cannot be obtained. Furthermore, the recess 2b of the case 2
The molding of the case 2, the cover 4, etc. was also required to be precise, such as requiring a certain degree of accuracy in the depth of the case 2, the height of the pressing portion 4b of the cover 4, and the thickness of the elastic body 5c.

This invention was made in order to eliminate such drawbacks, and it makes it easier to mold the elastic body itself, and uses a relatively small pressing force on the elastic body to effectively prevent water from entering from the outside of the cover and case. The purpose of the present invention is to provide a waterproofing device for an electric meter that can prevent the damage from occurring.

Hereinafter, one embodiment of the waterproofing device according to this invention will be described in detail based on FIG. 5.

5d in FIG. 5a is an elastic body molded into a semicircular shape, which is molded by a combination of one spherical mold and the other simple flat mold.
The elastic body 5d having a semicircular cross section formed in this way is fitted into the recess 2b of the case 2 as shown in FIG. That is, the flat portion 5e of the elastic body 5d
is arranged almost parallel to the bottom surface 2d of the fitting surface of the recess 2b in the case 2, and the curved surface portion 5f is placed on the bottom surface 2d.
The elastic body 5d is fitted so as to be in contact with both vertical surfaces 2c, 2c and the bottom surface 2d of the recess 2b, respectively. At this time, the elastic body 5c and the recess 2
There is an air space between both vertical surfaces 2c, 2c, and bottom surface 2d of b.
A section 8 is provided.

Thus, the pressing part 4b, which has a smaller diameter than the recess 2b of the cover 4, is fitted into the recess 2b while pressing the vicinity of the center of the flat part 5e of the elastic body 5d. When the bonding surface 4a is bonded, the state is as shown in FIG.
That is, by pressing the elastic body 5c of the pressing part 4b of the cover 4, the elastic body 5d fills the hollow part 8 and comes into pressure contact with both vertical surfaces 2c, 2c and the bottom surface 2d of the recess 2b of the case 2. become. Therefore, the concave portion 2b of the case 2 is elastically pressed by the elastic body 5d at three locations, A, B, and C, as shown in FIG. They can be effectively sealed against water entering their interior. Moreover, since the hollow part 8 is provided between both vertical surfaces 2c, 2c and the bottom surface 2d in the recessed part 2b of the case 2, the elastic body 5d is deformed by being pressed into a part where external pressure is small. Therefore, the deformed portion of the elastic body 5d fits into the cavity 8, and both vertical surfaces 2c in the cavity 8,
2c and the bottom surface 2d to press them, the pressing force of the cover 4 against the elastic body 5d may be relatively small.

In addition, although the size of the cross section of the elastic body is such that it can be inserted into the recess 2b provided in the case 2, when the elastic body is inserted into the recess 2b of the case 2, Even if the cross section of the elastic body is sized so as not to contact the surfaces 2c, 2c,
Any structure may be used as long as the bottom surface 2d of the recess 2b and both vertical surfaces 2c, 2c are pressed against each other when pressed by the pressing portion 4b of the cover 4. On the other hand, even if the width of the elastic body 5d is made slightly larger than the width of the recess 2b, since the elastic body 5d has a semicircular cross section, it will deform greatly in the width direction, so it will not fit into the recess 2b. It is easy to do so, and the sealing properties are also good. Note that since the amount of deformation of the elastic body 5d in the thickness direction (vertical direction) is not as large as that in the width direction, there is no risk that the cover 4 will tilt significantly due to the deformation in the thickness direction.

Furthermore, it is clear that the flat part of the elastic body is not necessarily arranged parallel to the bottom surface 2d of the recess 2b of the case 2, and the recess 2b may also be provided on the cover 4.

As explained above, this idea consists of internal elements,
The internal element is housed in a case and a cover, a recess with a rectangular cross section is formed in one of the opposing joint surfaces of the case and the cover, an elastic body is fitted in the recess, and the opposite In the waterproofing device for an electric meter, the elastic body is pressed by a pressing part formed on the other side of the joint surface to seal the internal element, and the elastic body is formed in a cross section with a diameter dimension that is approximately equal to the width of the recess. It is formed into a semicircular shape and is fitted into the recess so that the curved surface faces the bottom of the recess, and in this fitted state, there is a gap between the curved surface and both vertical surfaces and the bottom of the recess. A cavity is formed, and since at least one of the molds can be a flat plate for molding the elastic body, there is no need to worry about positioning two molds as in the conventional method. Additional steps can be omitted, and since there is no burr, molding is easy and the price is low.

Moreover, since the hollow portion is provided between the elastic body and the fitting surface of the recess before pressing the elastic body, the pressing force when pressing the elastic body is also the same as that of the conventional one. This not only simplifies the assembly work because it can be made smaller, but also because the bottom surface and both vertical surfaces of the fitting surface of the recess are brought into pressure contact with the elastic body, so that there is no leakage from the outside of the cover and the case to the inside thereof. It can also effectively prevent water from entering. Furthermore, since the elastic body has a semicircular cross section, the amount of deformation in the width direction is large, so even if it is slightly larger than the recess size, that is, even if the precision is low, there will be no negative effect on sealing performance and assemblability. is easy.

[Brief explanation of the drawing]

Figure 1 is a perspective view showing a conventional waterproofing device;
Figures 2 a to c and d to f are diagrams of a conventional waterproofing device in which an elastic body is fitted into a recess provided in a case, before the cover is attached to the case, and after the case is attached to the cover, respectively. Fig. 3 a to c are configuration diagrams showing the cross-sectional shape of a conventionally used elastic body, Fig. 4 is an explanatory diagram when molding a conventional elastic body, and Figs. 5 a, b, and c are state diagrams. An explanatory diagram showing the cross-sectional shape of the elastic body used in the electrical meter waterproofing device according to this invention, a diagram showing the elastic body fitted into a recess provided in the case, and a diagram showing the state in which the cover is attached to the case. It is a diagram. Note that the same reference numerals in the figures indicate the same or equivalent parts. 2...Case, 4...Cover, 2b...Recess,
2c... Vertical surface, 2d... Bottom surface, 5d... Elastic body, 5e... Flat portion, 5f... Curved surface portion. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] It has an internal element, a case and a cover for accommodating the internal element, and a recess with a rectangular cross section is formed on one of the opposing joint surfaces of the case and the cover,
An elastic body is fitted into the recess, and the elastic body is pressed by a pressing part formed on the other of the opposing joint surfaces to seal the internal element, wherein the pressing part is pressed against the internal element. The elastic body is formed to be smaller than the width of the recess and located approximately at the center of the width of the recess, and the elastic body is formed to have a semicircular cross section with a diameter that is approximately equal to the width of the recess. , the case and the cover are fitted into the recess so that the curved surface faces the bottom surface of the recess, and a gap is formed between the curved surface and both vertical surfaces and the bottom surface of the recess. When joined, the elastic body is pressed by the pressing part and deforms, and the elastic body presses both vertical surfaces and the bottom of the recess existing in the gap. .