JPS6349518B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a sealing structure for a casing of an electrical device, particularly a waterproof electric razor.

[Background Art] In a conventional waterproof electric razor, as shown in FIG. 8, an annular rubber sealing ring 21 is integrally molded with a motor mount 22 and protrudes from the motor mount 22. The fixing groove 23 of the motor mounting base 22 to which the ring 21 is fixed
The height of the inner circumferential wall 24 was lower than the height of the outer circumferential wall 25, or at most the same height. For this reason, the sealing ring 21 has an 8th
If it is pulled inward and falls down as shown in Figure a (the mounting base of the sealing ring 21 is expanded), and the tip of the sealing ring 21 is brought into close contact with the housing 26 during assembly, as shown in Figure 8b. There was a problem in that the tilting became large, the sealing effect was reduced, and water entered the interior from between the motor mounting base 22 and the housing 26.

[Objective of the Invention] The present invention has been made in view of the above-mentioned technical background, and its purpose is to prevent the deterioration of the sealing effect due to heat shrinkage of the sealing ring, and to improve the sealing effect. Located in providing high casing seal structure.

[Disclosure of the Invention] The seal structure of the casing of the present invention is such that the base of the sealing ring 1 is fitted into the annular fixing groove 2, and the height of the inner circumferential wall 3 of the fixing groove 2 is set higher than the height of the outer circumferential wall 4 for sealing. This is characterized in that the height of the ring 1 is increased toward the sealing direction, thereby achieving the above object.

An embodiment of the present invention will be described below in detail with reference to a waterproof electric razor, but the present invention is not limited to this embodiment. As shown in FIG. 1, the casing A is composed of a housing 6, a motor mount 7, and an outer blade mount 8. The motor mount 7 is sandwiched between the housing 6 and the outer blade mount 8. It is assembled in such a way. Housing 6
A battery storage chamber 9 is provided at the bottom of the battery storage chamber 9, and the lower opening of the battery storage chamber 9 is closed by a bottom cover 10. The motor 11 is attached to the lower surface of the motor mount 7 and housed in the upper part of the housing 6, and the inner blade 14 is attached to the motor shaft 13, which is inserted into the motor mount 7 through the bellows packing 12. A switch lever 16 is also inserted through the motor mounting base 7. Further, an outer cutter 15 is attached to the outer cutter mounting base 8, and the outer cutter 15 can be protected by an outer cutter cover 17. The seal structure of the X section in FIG. 1 is shown in an enlarged scale in FIG. The motor mounting base 7 is made of glass-filled ABS resin, and an annular fixing groove 2 is provided on its lower surface, and a sealing ring made of styrene-based thermoplastic synthetic resin is installed in the fixing groove 2. The base (upper peripheral edge) of the (O-ring) 1 is fixed to the motor mounting base 7 by simultaneous integral molding, and the tip edge of the sealing ring 1 is made to protrude from the fixing groove 2. The height L ₂ of the inner circumferential wall 3 of the fixing groove 2 is greater than the height L 3 of the outer circumferential wall ₄ , and in the illustrated example, the height of the inner circumferential wall 3 is greater than the height L 3 of the outer circumferential wall 4.
L ₂ is approximately 1/2 of the height L ₁ of sealing ring 1,
The height L ₃ of the outer peripheral wall 4 is set as L ₃ <L ₂ . As a result, the inner circumferential side of the sealing ring 1 is supported by the inner circumferential wall 3, and it is largely prevented from falling inward due to heat shrinkage during molding (Fig. 2). When the sealing ring 1 is installed and tightened, the sealing ring 1 deforms more on the outer circumferential side because the outer circumferential wall 4 is lowered (Fig. 3), and does not fall inward, causing the sealing ring 1 to deform between itself and the housing 6. This greatly improves the sealing effect. The inner circumferential wall 3 and outer circumferential wall 4 that hold the sealing ring 1 here need to be lower than the height of the sealing ring 1, but this means that when the sealing ring 1 is tightened with the housing 6, the sealing ring By releasing the amount of deformation of 1, the sealing ring 1
This is to make it possible to reduce the reaction force deformation to the deformation of the ring, maintain a high sealing effect, reduce deterioration of the sealing ring 1, and obtain a uniform sealing force over a long period of time. .

The one shown in FIG. 4 is another example of the present invention, in which a rib 5 is partially projected longer than the tip edge of the sealing ring 1 from the inner circumferential wall 3 side of the fixing groove 2 at a distance from the sealing ring 1. be. The rib 5 can protect the sealing ring 1, and prevent the sealing ring 1 from being damaged or deformed, for example, while the motor mounting base 7 to which the sealing ring 1 is attached is being transported. It can prevent accidents. Of course, in FIG. 5, a notch 18 is provided to prevent the rib 5 from coming into contact with the housing 6.

What is shown in FIGS. 6 and 7 is still another example of the present invention, in which a rib 5 is projected longer than the tip edge of the sealing ring 1 from the outer peripheral wall 4 side and apart from the sealing ring 1. This is what I did.

[Effects of the Invention] As described above, in the present invention, the height of the inner circumferential wall of the fixing groove is made higher than the height of the outer circumferential wall in the sealing direction of the sealing ring. The inner circumferential wall can prevent the sealing ring from falling inward due to heat shrinkage, and therefore the inner circumferential wall has the advantage of preventing deterioration of the sealing effect. In addition, since the height of the outer circumferential wall of the fixing groove is lower than the height of the inner circumferential wall in the sealing direction of the sealing ring, when tightening the sealing ring, the sealing ring deforms greatly on the outer circumferential wall and may fall inward. In addition to this, the sealing ring is pressed almost perpendicularly to the sealing surface of the housing due to the balance between the force that causes it to fall inward and the force that tries to deform outward, which improves the sealing effect. be.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing one embodiment of the present invention, and FIG.
The figure is a sectional view showing the attachment part of the sealing ring same as above, FIG. 3 is a sectional view showing the sealing state of the same sealing ring as above, and FIG. 4 is a sectional view showing the attachment part of the sealing ring in another example of the same as above. Fig. 5 is a sectional view showing the sealing state of the sealing ring same as above, Fig. 6 is a sectional view showing the attachment part of the sealing ring in still another example of the same above, and Fig. 7 is a sectional view of the same sealing ring as above. FIGS. 8a and 8b are cross-sectional views showing a sealing state, and are cross-sectional views of a conventional example, in which 1 is a sealing ring, 2 is a fixing groove, 3 is an inner circumferential wall, and 4 is an outer circumferential wall.

Claims (1)

[Claims] 1. In a casing in which the base of a sealing ring is integrally molded by fitting into an annular fixing groove, the height of the inner circumferential wall of the fixing groove is set to be higher than the height of the outer circumferential wall of the sealing ring. A casing seal structure characterized by being raised in the direction. 2. The casing seal structure according to claim 1, characterized in that a rib that is higher than the tip edge of the sealing ring projects from the edge of the fixing groove.