Sealed structure

Abstract

To provide a sealing structure that enables stable sealing performance to be obtained regardless of manufacturing variations. [Solution] A groove 21 with a concave cross section is formed in the housing 2, and a packing 3 is inserted into the groove 21 and a cover 4 is attached to close the opening of the groove 21, thereby crushing the packing 3. The cross-sectional area of ​​the packing 3 is set to be equal to or greater than the cross-sectional area of ​​the groove 21 even if there is manufacturing variation, and the housing 2 is provided with a surplus storage section 22 that communicates with the groove 21 and stores the surplus portion 3a of the packing 3 that exceeds the cross section of the groove 21.

Description

[Technical Field]

[0001] The present invention relates to a sealing structure for waterproofing, watertightness or airtightness. [Background technology]

[0002] For example, when waterproofing the housing of a commercial radio, a sealing structure is adopted in which a concave waterproof groove is formed on the outer periphery of the opening of the housing, a waterproof gasket is inserted into this waterproof groove, and a lid is attached to the housing to crush the waterproof gasket. Waterproof gaskets with various cross-sectional shapes have been developed to improve waterproofness and sealing properties (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-23268 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, the waterproof performance is affected by the amount of deformation (deformation) of the waterproof gasket and its filling rate (= cross-sectional area of ​​the waterproof gasket / cross-sectional area of ​​the waterproof groove), and the higher the filling rate, the better the waterproof performance, but if the filling rate exceeds 100%, the waterproof gasket may overflow from the waterproof groove. In other words, when inserting the waterproof gasket into the waterproof groove of the housing and attaching the lid, a problem may occur in which the lid does not close properly and opens.

[0005] For this reason, in the past, it was necessary to take into account the unavoidable variations that occur during manufacturing and set the design value (target value) of the filling rate low so that the filling rate would not exceed 100% at the upper limit of the variations. For example, assuming a manufacturing variation of ±5%, the design value of the filling rate was set to 95%, and the filling rate was set to 90% to 100% due to manufacturing variations. This resulted in variations in the filling rate, making it difficult to achieve stable waterproof performance.

[0006] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a sealing structure that makes it possible to obtain stable sealing performance regardless of manufacturing variations. [Means for solving the problem]

[0007] In order to solve the above problem, the invention described in claim 1 is a sealing structure in which a groove with a concave cross section is formed in a first member, a gasket is inserted into the groove, and a second member is attached to block the opening of the groove, thereby crushing the gasket, wherein the cross-sectional area of ​​the gasket is set to be equal to or greater than the cross-sectional area of ​​the groove even if there is manufacturing variation, and the first member is provided with a surplus storage section that communicates with the groove and stores the surplus portion of the gasket that exceeds the cross section of the groove.

[0008] The invention as set forth in claim 2 is characterized in that in the sealing structure as set forth in claim 1, the surplus storage portion is provided on the side opposite to the opening of the groove. [Effects of the Invention]

[0009] According to the invention described in claim 1, the cross-sectional area of ​​the packing is set to be equal to or larger than the cross-sectional area of ​​the groove regardless of manufacturing variations, and an excess storage section is provided in communication with the groove. Therefore, even if the cross-sectional area of ​​the packing is at the upper limit of manufacturing variations, the excess part of the packing that exceeds the cross-section of the groove is stored in the excess storage section, and the groove stores packing of an area equal to the cross-sectional area of ​​the groove. In other words, the packing filling rate is 100%.

[0010] On the other hand, even if the cross-sectional area of ​​the packing is at the lower limit of manufacturing variations, the cross-sectional area of ​​the packing will be the same as the cross-sectional area of ​​the groove, and the groove will contain an amount of packing equal to the cross-sectional area of ​​the groove. In other words, the packing filling rate will be 100%. In this way, the groove filling rate will always be 100% regardless of manufacturing variations, making it possible to ensure stable sealing performance.

[0011] According to the invention of claim 2, since the surplus storage portion is provided on the side opposite to the opening of the groove, it is possible to easily and properly form the groove and the surplus storage portion. Moreover, when the second member is attached to close the opening of the groove and the packing is crushed, it is possible to smoothly and easily store the surplus portion of the packing in the surplus storage portion. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a conceptual diagram showing a sealing structure according to an embodiment of the present invention; [Figure 2] 1A is a conceptual diagram showing a sealed state when the cross-sectional area of ​​the packing is at the lower limit of manufacturing variation, FIG. 1B is a conceptual diagram showing a sealed state when the cross-sectional area of ​​the packing is at the intermediate value of manufacturing variation, and FIG. 1C is a conceptual diagram showing a sealed state when the cross-sectional area of ​​the packing is at the upper limit of manufacturing variation in the sealing structure of FIG. [Figure 3] FIG. 1 is a conceptual diagram showing a conventional sealing structure. [Figure 4] 4 is a conceptual diagram showing a state in which the lid is attached when the cross-sectional area of ​​the packing exceeds the cross-sectional area of ​​the groove in the sealing structure of FIG. 3. FIG. [Figure 5] 4A is a conceptual diagram showing the sealed state when the cross-sectional area of ​​the packing is at the lower limit of manufacturing variation in the sealing structure of FIG. 3; FIG. 4B is a conceptual diagram showing the sealed state when the cross-sectional area of ​​the packing is at the intermediate value of manufacturing variation; and FIG. 4C is a conceptual diagram showing the sealed state when the cross-sectional area of ​​the packing is at the upper limit of manufacturing variation in the sealing structure of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0013] The present invention will be described below based on the illustrated embodiments.

[0014] Fig. 1 is a conceptual diagram showing a sealing structure 1 according to an embodiment of the present invention, and Fig. 2 is a conceptual diagram showing various sealing states achieved by this sealing structure 1. This sealing structure 1 is a structure for waterproofing, watertightness, or airtightness, and in this embodiment, a case where the housing of a commercial radio is waterproofed will be mainly described. That is, the following describes a waterproof structure for ensuring waterproofing when an opening (aperture) is formed in a housing (first member) 2 and a cover (second member) 4 is attached to cover this opening.

[0015] This sealing structure 1 basically has a groove 21 formed along the outer periphery of the open part of the housing 2. This groove 21 has a concave cross section, and is roughly rectangular with one side (top side) open. Then, with a packing 3 inserted into this groove 21, a cover 4 is attached so as to close the opening of the groove 21, and the packing 3 is crushed.

[0016] Here, the packing 3 is substantially string-shaped, and in this embodiment, its cross section is formed to be substantially circular, and the cross-sectional area of ​​the packing 3 is set so that it is equal to or greater than the cross-sectional area of ​​the groove 21 even if there is manufacturing variation. In other words, even if the cross-sectional area of ​​the packing 3 increases or decreases due to manufacturing variation, the cross-sectional area of ​​the packing 3 is set and designed so that it is always equal to or greater than the cross-sectional area of ​​the groove 21.

[0017] For example, assuming that the manufacturing variation is ±5%, the design value (target value) of the cross-sectional area of ​​the packing 3 is set so that the cross-sectional area of ​​the packing 3 is equal to or greater than the cross-sectional area of ​​the groove 21 even if the manufacturing variation becomes -5%. That is, in this case, the design value (intermediate value) of the cross-sectional area of ​​the packing 3 is set to 105% of the cross-sectional area of ​​the groove 21 (100%), so that the cross-sectional area of ​​the packing 3 becomes 100% at the lower limit of the manufacturing variation (-5%) and becomes 110% at the upper limit of the manufacturing variation (+5%). Here, the cross-sectional area of ​​the packing 3 may be set taking into consideration not only the manufacturing variation of the packing 3 but also the manufacturing variation of the groove 21.

[0018] Meanwhile, the housing 2 is provided with a surplus storage section 22 that communicates with the groove 21 and stores the surplus portion 3a of the packing 3 that exceeds (protrudes from) the cross section of the groove 21. That is, in this embodiment, a concave surplus storage section 22 is formed on the side facing the opening of the groove 21, that is, in communication with and adjacent to a corner of the bottom side (the side that has little effect on waterproof performance) of the groove 21. As a result, the cross section of the outer periphery of the open part of the housing 2 has a shape in which a small concave surplus storage section 22 is formed on the bottom side of the large concave groove 21. Note that in FIG. 1 , the area of ​​depth d1 of the groove 21 is a sealed portion that contributes to waterproofing, the area of ​​depth d2 of the surplus storage section 22 is a relief portion that does not contribute to waterproofing, and the height d3 is a crushing allowance for the packing 3.

[0019] Here, the shape and size of the surplus accommodating portion 22 are set so as to reliably accommodate the surplus portion 3a of the packing 3 (the portion that cannot be accommodated in the groove 21). That is, assuming a manufacturing variation of ±5% as described above, the surplus portion 3a of the packing 3 will be at its maximum at the upper limit of the manufacturing variation (+5%), and the cross-sectional area of ​​the surplus portion 3a will be 10% of the cross-sectional area of ​​the groove 21. The shape and size of the surplus accommodating portion 22 are set so as to reliably and appropriately accommodate this maximum surplus portion 3a.

[0020] Note that the above explanation is based on the assumption that manufacturing variations are ±5%, but in reality, manufacturing variations are much smaller, and therefore the size of the surplus storage portion 22 is smaller than that shown in Figures 1 and 2. In reality, the packing 3 does not deform to perfectly follow the cross-sectional shape of the groove 21, and gaps will inevitably occur somewhere (for example, at the corners), so the cross-sectional area of ​​the packing 3 and other factors must be set taking this into consideration.

[0021] According to the sealing structure 1 configured as described above, the cross-sectional area of ​​the packing 3 is set to be equal to or larger than the cross-sectional area of ​​the groove 21 regardless of manufacturing variations, and the surplus storage portion 22 is provided in communication with the groove 21. Therefore, even if the cross-sectional area of ​​the packing 3 is at the upper limit of manufacturing variations, the surplus portion 3a of the packing 3 that exceeds the cross section of the groove 21 is stored in the surplus storage portion 22, and the groove 21 stores the packing 3 with an area equivalent to the cross-sectional area of ​​the groove 21. In other words, the filling rate of the packing 3 is 100% (excluding gaps that may occur unavoidably).

[0022] On the other hand, even if the cross-sectional area of ​​the packing 3 is at the lower limit of manufacturing variations, the cross-sectional area of ​​the packing 3 is equal to the cross-sectional area of ​​the groove 21, and the groove 21 accommodates an area of ​​packing 3 equal to the cross-sectional area of ​​the groove 21. In other words, in this case too, the filling rate of the packing 3 is 100%, and the filling rate is always constant regardless of the cross-sectional area of ​​the packing 3.

[0023] That is, in a conventional sealing structure in which only a concave groove 51 is formed in a housing 5 as shown in Fig. 3, if the cross-sectional area of ​​the packing 6 exceeds the cross-sectional area of ​​the groove 51, when the packing 6 is inserted into the groove 51 and the lid 7 is attached, the lid 7 will not close properly and will open as shown in Fig. 4. For this reason, conventionally, the design value (target value) of the cross-sectional area of ​​the packing 6 has been set low so that the cross-sectional area of ​​the packing 6 does not exceed the cross-sectional area of ​​the groove 51 at the upper limit of manufacturing variation.

[0024] For example, assuming a manufacturing variation of ±5%, the design value of the cross-sectional area of ​​the packing 6 is set to 95% of the cross-sectional area of ​​the groove 51. As a result, as shown in Figure 5(a), the filling rate (cross-sectional area of ​​the packing 6) is 90% at the lower limit of the manufacturing variation, as shown in Figure 5(b), the filling rate is 95% at the intermediate value of the manufacturing variation, and as shown in Figure 5(c), the filling rate is 100% at the upper limit of the manufacturing variation. This resulted in variations in the filling rate, making it impossible to obtain stable waterproof performance.

[0025] In contrast, in the present sealing structure 1, assuming a manufacturing variation of ±5% as described above, at the lower limit (-5%) of the manufacturing variation, the cross-sectional area of ​​the packing 3 is 100% of the cross-sectional area of ​​the groove 21, and the entire cross-section of the packing 3 is accommodated in the groove 21, as shown in FIG. 2(a). At the intermediate value of the manufacturing variation, the cross-sectional area of ​​the packing 3 is 105% of the cross-sectional area of ​​the groove 21, and as shown in FIG. 2(b), 100% of the cross-section of the packing 3 is accommodated in the groove 21, with the remaining 5% of the surplus portion 3a being accommodated in the surplus accommodation portion 22. At the upper limit (+5%) of the manufacturing variation, the cross-sectional area of ​​the packing 3 is 110% of the cross-sectional area of ​​the groove 21, and as shown in FIG. 2(c), 100% of the cross-section of the packing 3 is accommodated in the groove 21, with the remaining 10% of the surplus portion 3a being accommodated in the surplus accommodation portion 22.

[0026] In this way, the filling rate of the groove 21 is always 100% regardless of manufacturing variations (the contact area and contact pressure between the groove 21 and the packing 3 do not fluctuate), making it possible to ensure stable sealing performance.

[0027] Furthermore, since the surplus storage portion 22 is provided on the side opposite the opening of the groove 21, it is possible to easily and properly form the groove 21 and the surplus storage portion 22. Moreover, when the cover 4 is attached so as to close the opening of the groove 21 and the packing 3 is crushed, it is possible to smoothly and easily accommodate the surplus portion 3a of the packing 3 in the surplus storage portion 22. Therefore, even if the packing 3 is made of a material that is difficult to deform, the surplus portion 3a of the packing 3 can be smoothly and easily accommodated in the surplus storage portion 22, and it is possible to properly attach the cover 4 (close the lid).

[0028] Although the embodiments of the present invention have been described above, the specific configuration is not limited to the above embodiments, and design changes within the scope of the present invention are also included within the scope of the present invention. For example, the above embodiments have been described for waterproofing the housing 2 of a commercial radio, but the present invention may also be applied to other devices or for the purpose of airtightness. Furthermore, the packing 3 includes all sealing materials (watertight materials, airtight materials) such as O-rings, gaskets, and seals. Furthermore, the surplus storage section 22 may be provided in a location or position different from that described above.

[0029] 1 Sealed structure 2. Housing (first component) 21 Groove 22 Surplus storage section 3. Packing 3a Excess part 4 Cover (second part)

Claims

1. A sealing structure in which a groove having a concave cross section is formed in a first member, a packing is inserted into the groove, and a second member is attached to close the opening of the groove, thereby crushing the packing, The cross-sectional area of ​​the packing is set to be equal to or greater than the cross-sectional area of ​​the groove even if there is manufacturing variation, The first member is provided with a surplus accommodating portion that communicates with the groove and accommodates a surplus portion of the packing that exceeds the cross section of the groove. A sealed structure characterized by:

2. The surplus storage section is provided on a side opposite to the opening of the groove. The sealing structure according to claim 1 .

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