JP5130982B2 - Grommet and waterproof structure of electronic equipment using it - Google Patents

Description

  The present invention relates to a grommet having a waterproof function and a waterproof structure of an electronic device using the grommet.

As a conventional grommet, there is a cable insertion part with a bottomed cylindrical shape so that the bottom part can be broken, and when it is necessary to insert the cable, it is necessary to break the bottom part and use the cable without insertion. In some cases, the bottom part functions as a waterproof structure (see, for example, Patent Document 1). This grommet is fitted into the U-shaped groove of the lower case, and when the upper case is united with the lower case, the lower end of the lower case comes into contact with the grommet's ridge so that falling off from the U-shaped groove is restricted. Is done.
JP 2005-209405 A

  In the conventional grommet described above, since only one cable insertion portion is provided, when it is necessary to lead out a plurality of cables from the housing, the number of grommets corresponding to the number of cables is required. In addition, there is a problem that the manufacturing cost increases because the structure of the housing must be changed. In addition, when switches for operating electronic devices are provided, a special structure that exclusively covers the switches with a waterproofing member or the like is required so as not to impair the waterproof function of the housing. There was a problem that the cost increased.

  The present invention has been made in view of the above-described conventional problems, and an object of the present invention is to provide a grommet with reduced manufacturing cost and a waterproof structure for an electronic device using the grommet.

In order to achieve this object, the present invention has a bottomed cylindrical shape, the bottom portion is formed so as to be ruptured, and the whole having a cable insertion portion through which a cable can be inserted by breaking the bottom portion is formed of rubber. A grommet, which is provided with a connecting portion that integrates a plurality of the cable insertion portions arranged side by side in a row, and a flexible operation portion for pressing the switch is integrally connected to the connecting portion. It is a thing.

  The present invention includes first and second cases each having an opening on one side and formed in a box shape, and by forming the housing by bringing the two cases into contact with each other and combining them. A waterproof structure for an electronic device in which the grommet according to the invention is attached to each opening end, wherein a pressing groove is provided in the connecting portion, and a recess into which the cable insertion portion is fitted is provided in the opening end of the first case. The opening end of the second case is provided with a rib that presses the bottom of the pressing groove in the direction in which the cable insertion portion is fitted into the recess by combining the first and second cases. Is.

  According to the present invention, even if there is a change in the number of cables to be led out, it is possible to cope with one grommet, so that not only the versatility of the grommet is improved, but also the housing to which the grommet is attached is made common. Therefore, the manufacturing cost can be reduced. Further, since the cable lead-out position can be selected from among the plurality of cable insertion portions, the degree of freedom in designing the cable wiring in the housing is increased. Since the operation part for operating the switch provided inside the housing is provided integrally with the grommet, it is not necessary to provide a waterproof structure dedicated to the operation part, and thus the manufacturing cost can be reduced.

  According to one of the above inventions, the portion pressed by the rib formed on the case is formed with a thin bottom portion so that the bottom portion is easy to break in order to pass the cable, and is not a cable insertion portion with low rigidity. Thus, since the connecting portion that is difficult to deform is used, the sealing property between the grommet and the concave portion of the case is improved, so that the waterproof property is improved.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 and 2, the grommet generally indicated by reference numeral 1 includes four cable insertion portions 2A to 2D arranged in a row, a collar 3A connecting the cable insertion portions 2A and 2B, and a cable insertion portion 2C, 2D is composed of a collar 3B, a coupling part 4 that couples the cable insertion parts 2A to 2D via the collars 3A, 3B, and an operation part 6 that is connected to the coupling part 4 via a collar 5. The whole is integrally formed of rubber.

  The cable insertion portions 2A to 2D are formed in a bottomed rectangular tube shape, and the bottom portion 2a is formed thin so as to be easily broken as shown in FIG. The connecting portion 4 is formed in a substantially rectangular parallelepiped shape that is relatively thicker and longer than the cable insertion portions 2A to 2D, and corresponds to the center portion of the cable insertion portions 2A to 2D and both ends of the operation portion 6. A total of six pressing grooves 7A to 7F are provided at each position.

  As shown in FIG. 1 (B), these pressing grooves 7A to 7F have an opening 7a on the upper side and a bottom 7b formed with a width narrower than the opening 7a, and are formed in a substantially trapezoidal shape in front view. The back surface portion 7c is closed by the connecting portion 4 as shown in FIGS. As shown in FIG. 1B, the bottom portion 7b is positioned above the upper end surfaces of the cable insertion portions 2A to 2D by a slight distance δ.

  The operation portion 6 is formed in a flat cylindrical shape, and is attached to the flange 5 via a flexible support portion 5a having a ring shape and a small thickness as shown in FIGS. 1 (D) and 2 (A). It is connected, and a pressing portion 6a formed in a columnar shape is integrally projected at the center of the back surface. Accordingly, when the operation unit 6 is pressed in the direction of arrow A with a finger or the like, the support unit 5a is elastically deformed, and the pressing unit 6a moves in the direction of arrow A.

  In FIG. 3, reference numeral 10 denotes an electronic device. As shown in FIG. 4, a housing is formed by the first case 11 and the second case 12 both of which are open on one surface. On the inner side of the rear plate 13 of the first case 11, studs 14, 14 are integrally projected, and an opposing wall 16 facing the bottom plate 15 is integrally projected. Between the opposing wall 16 and the bottom plate 15, an engaging groove 16a into which the flanges 3A, 3B, 5 of the grommet 1 are engaged is provided. As shown in FIG. 6 (B), the opening end 15a of the bottom plate 15 has first U-shaped grooves 7A to 7D as recesses into which the respective cable insertion portions 2A to 2D of the grommet 1 are fitted, and an operation portion. And a second U-shaped groove 18 is provided.

  In FIG. 4, reference numeral 20 denotes a printed circuit board fixed to the rear plate 13 of the first case 11 via the stud 21, and is operated by the pressing portion 6 a of the operation portion 6 as shown in FIG. A switch 22 is mounted.

  As shown in FIGS. 4 and 7, the bottom plate 25 of the second case 12 is provided with an opening end 25 a that is in contact with the opening end 15 a of the first case 11. The cable insertion portions 2A to 2D are fitted into the first U-shaped grooves 17A to 17D of the first case 11 at the end on the bottom plate 25 side of the front plate 26 of the first case 11 as will be described later. Six ribs 27 inserted into the pressing grooves 7A to 7F of the grommet 1 and extending at the lower end to the opening end 25a of the bottom plate 25 are integrally projected. Further, the opening end 25a of the bottom plate 25 is formed on the upper end surface of each cable insertion portion 2A to 2D of the grommet 1 as shown in FIG. 7 when the opening end 25a is brought into contact with the opening end 15a of the first case 11. Interact.

  As shown in FIG. 4, the first case 11 and the second case 12 are screwed into the studs of the first case 11 with the open ends 15a and 25a facing each other. As a result, the housing of the electronic device 10 is formed.

  Next, a method of mounting the grommet 1 configured as described above on the opening end 15a of the first case 11 and the opening end 25a of the second case 12 will be described. By engaging the hooks 3A, 3B, 5 of the grommet 1 in the engaging groove 16a of the first case 11 as shown in FIGS. 4 and 5, the cable of the grommet 1 as shown in FIG. 6 (B). The insertion parts 2A to 2D are fitted into the first U-shaped grooves 17A to 17D of the first case 11, and the operation part 6 is exposed from the second U-shaped groove 18.

  Next, the opening end 25a of the second case 12 is brought into contact with the opening end 15a of the first case 11, and the rib 27 of the second case 12 is inserted into the pressing grooves 7A to 7F of the grommet 1 as shown in FIG. Engage. In this state, as shown in FIG. 4, the screws 30 and 30 are screwed into the studs of the first case 11, whereby the first and second cases 11 and 12 are combined to form the casing of the electronic device 10. The At this time, since the lower end of the rib 27 presses the bottom 7b of the pressing grooves 7A to 7D downward, the grommet 1 is also pressed downward.

  Here, as described above, the bottom portion 7b is positioned above the upper end surfaces of the cable insertion portions 2A to 2D by a slight distance δ, and the lower end of the rib 27 extends to the open end 25a of the bottom plate 25. Therefore, the force that presses the grommet 1 downward by the ribs 27 is relatively larger than the force that presses the grommet 1 downward by the opening end 25a of the second case 12. For this reason, since the force for fitting the cable insertion portions 2A to 2D of the grommet 1 to the first U-shaped grooves 17A to 17D of the first case 11 is increased, the cable insertion portions 2A to 2D and the first U Watertightness between the letter-shaped grooves 17A to 17D is increased, and waterproofness is improved.

  In addition, the thickness of the portion to be pressed by the ribs 27 is sufficient to obtain sufficient rigidity without forming the bottom portion 2a thin so that the bottom portion 2a can be easily broken in order to pass the cable, and not having the low-rigidity cable insertion portions 2A to 2D. By forming the connecting portion 4 that is formed to be difficult to be deformed, the water tightness between the cable insertion portions 2A to 2D and the first U-shaped grooves 17A to 17D becomes higher.

  By attaching the grommet 1 to the opening end 15a of the first case 11 and the opening end 25a of the second case 12 in this way, the pressing portion 6a of the operation portion 6 is switched as shown in FIG. Therefore, the switch 22 can be operated by the pressing portion 6a by pressing the operation portion 6 in the arrow A direction from the outside of the housing.

  Since the grommet 1 configured in this way has a plurality of cable insertion portions 2A to 2D, it is possible to cope with one grommet 1 even if the number of cables to be led out changes. The general versatility of the grommet can be improved, and the housing for mounting the grommet can be made common, so that the manufacturing cost can be reduced. Further, since the cable lead-out position can be selected from among the plurality of cable insertion portions 2A to 2D, the degree of freedom in the cable wiring design in the housing is increased.

  In addition, since the operation unit 6 for operating the switch 22 provided inside the housing is provided integrally with the grommet 1, it is not necessary to provide a waterproof structure dedicated to the operation unit 6, and thus the manufacturing cost can be reduced.

The grommet which concerns on this invention is shown, The figure (A) is a top view, The figure (B) is the I (B) arrow figure in the figure (A), The figure (C) is I in the figure (B). (C) -I (C) sectional drawing and the figure (D) are I (D) -I (D) sectional drawings in the figure (B). FIG. 4A is a perspective view of the grommet according to the present invention viewed from the front side, and FIG. 4B is a perspective view of the grommet according to the present invention viewed from the back side. It is a top view of the electronic device with which the grommet which concerns on this invention was mounted | worn. It is the IV-IV sectional view taken on the line in FIG. 3A is a cross-sectional view taken along line V (A) -V (A) in FIG. 3, and FIG. 3B is a cross-sectional view taken along line V (B) -V (B) in FIG. FIG. 6A is a plan view of the main part showing a state in which the second case is removed from the electronic device with the grommet according to the present invention attached, and FIG. ) Arrow view. FIG. 7 is a VI (B) arrow view in FIG. 6 (A) showing a state in which the first and second cases are combined in the electronic device with the grommet according to the present invention attached.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Grommet, 2A thru | or 2D ... Cable insertion part, 2a ... Bottom part, 4 ... Connection part, 6 ... Operation part, 7A thru | or 7F ... Pressing groove, 7b ... Bottom part, 10 ... Electronic device, 11 ... 1st case, 12 ... 2nd case, 15a, 25a ... Open end, 17A thru | or 17D ... 1st U-shaped groove | channel (recessed part), 22 ... Switch, 27 ... Rib.

Claims (2)

A grommet formed entirely of rubber with a cable insertion part that is formed in a bottomed cylindrical shape so that the bottom part can be broken and the cable can be inserted by breaking the bottom part,
A plurality of cable insertion portions are arranged in a row and integrated to provide a connecting portion, and a flexible operation portion for pressing the switch is integrally connected to the connecting portion. Grommet to do. Both cases are provided with first and second cases which are open on one side and are formed in a box shape, and a case is formed by bringing the cases into contact with each other and combining them, and the openings of the two cases. A waterproof structure for an electronic device to which the grommet according to claim 1 is attached,
A pressing groove is provided in the connecting part,
Providing a recess into which the cable insertion portion is fitted at the opening end of the first case;
A rib is provided at the opening end of the second case to press the bottom of the pressing groove in a direction in which the cable insertion portion is fitted into the recess by combining the first and second cases. A waterproof structure for electronic devices.

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