JP2021002608A - Screw fastening structure and assembly unit - Google Patents

Abstract

To provide a screw fastening structure and an assembly unit that can prevent the head and the housing of a screw from becoming large.SOLUTION: A screw fastening structure 10 includes a fastened material 14, a fastening member 12, and a screw 16. The fastened material 14 is provided with a mounting hole 28. The fastening member 12 includes a female screw 22 coaxial with the mounting hole 28, and includes a flow passage 24 that opens to the seat surface 21 with which the fastened material 14 abuts and penetrates a housing 11 in the axial direction of the female screw 22. The screw 16 is screwed into the female screw 22 through the mounting hole 28, such that the fastened material 14 is sandwiched by the head 32 and the fastening member 12.SELECTED DRAWING: Figure 2

Description

The present invention relates to a screw fastening structure and an assembly unit.

A housing having a water resistant structure is generally known.
For example, Patent Document 1 discloses a configuration in which various waterproof structures are provided in a housing of an electric device.

Japanese Unexamined Patent Publication No. 2000-216556

Patent Document 1 discloses a waterproof structure in which a screw is screwed onto the outside of a waterproof packing provided on a housing to prevent water droplets from entering the water intrusion prohibited range in the housing by the waterproof packing.
Further, Patent Document 1 discloses a waterproof structure that prevents water droplets from entering the water intrusion prohibited range in the housing by fastening a screw with a waterproof seal.
However, as in Patent Document 1, when a screw is screwed onto the outside of the waterproof packing provided on the housing, the housing protrudes outward by the amount of the screw and becomes large.
Further, when a screw with a waterproof seal is used as in Patent Document 1, the head of the screw becomes large.

An object of the present invention is to provide a screw fastening structure and an assembly unit that solves any of the above-mentioned problems.

The screw fastening structure of the first aspect includes a material to be fastened provided with a mounting hole and a female screw coaxial with the mounting hole, and is opened in a bearing surface to which the material to be fastened abuts in the axial direction of the female screw. A fastening member having a flow passage penetrating the housing, and a screw that sandwiches the fastening member with the fastening member by the head by inserting the mounting hole and screwing it into the female screw. , Equipped with.

The assembly unit of the second aspect includes the screw fastening structure and the housing.

According to this aspect, it is possible to prevent the housing and the head of the screw from becoming large.

It is a top view which shows the fastening destination member of the screw fastening structure in 1st Embodiment. It is sectional drawing which shows the screw fastening structure in 1st Embodiment. It is a perspective view which shows the fastening end member of the screw fastening structure in 2nd Embodiment. It is sectional drawing which shows the screw fastening structure in 2nd Embodiment. It is a perspective view which shows the fastening destination member of the screw fastening structure in 3rd Embodiment. It is sectional drawing which shows the screw fastening structure in 3rd Embodiment. It is sectional drawing which shows the screw fastening structure in 4th Embodiment of a minimum structure.

Hereinafter, each embodiment will be described with reference to the drawings. The same or corresponding configurations are designated by the same reference numerals in all drawings, and common description will be omitted.

<First Embodiment>
An embodiment of the screw fastening structure will be described with reference to FIGS. 1 and 2.

(Constitution)
The assembly unit 1 includes a screw fastening structure 10 and a housing 11.
The screw fastening structure 10 includes a fastening member 12, a member to be fastened 14, and a screw 16.

For example, as shown in FIGS. 1 and 2, the fastening member 12 may be provided in the housing 11, and the material to be fastened 14 may close the housing 11. At that time, the material to be fastened 14 is attached to the housing 11 to close the opening OP of the housing 11.
For example, the housing 11 may have a bottom 18 and an opening OP above.
For example, the material to be fastened 14 may be a lid member that expands so as to close the opening OP of the housing 11.

In the embodiment, as an example, the bottom portion 18 is located horizontally below and the material to be fastened 14 is located horizontally above.

The fastening member 12 is fixed to the bottom 18 of the housing 11.
The fastening member 12 is erected in a cylindrical shape from the bottom 18 of the housing 11.
The fastening member 12 includes a seat surface 21 and a female screw 22.
The fastening member 12 has a flow passage 24.
For example, the fastening member 12 may have an annular inclined surface 23.
For example, the fastening member 12 and the housing 11 may be integrally molded products.
For example, the number of pairs of the fastening member 12 and the screw 16 may be provided in order to attach the fastening member 14 to the housing 11.

For example, the seat surface 21 may be formed flat on the upper end of the fastening member 12 in the horizontal direction.
The female screw 22 is formed inside the fastening member 12 in the vertical direction, the upper portion is opened to the seat surface 21, and the lower portion is closed by the bottom 18 of the housing 11.
An annular inclined surface 23 is formed on the opening edge of the female screw 22 on the seat surface 21.
For example, the annular inclined surface 23 may be formed in a conical shape having an outer diameter 23a larger than the hole diameter of the mounting hole 28 described later.
Examples of the annular inclined surface 23 include a chamfer surface (C surface), but the surface is not limited to the C surface and may be another inclined surface.

The flow passage 24 is open to the seat surface with which the material to be fastened comes into contact.
The flow passage 24 penetrates the housing 11 in the axial direction of the female screw 22.
For example, the flow passage 24 is open to the outside in the housing 11 at the bottom 18 of the housing 11.
The flow passage 24 is a distribution groove in which a part of the female screw 22 in the circumferential direction is cut out radially outward beyond the outer circumference 23a of the annular inclined surface 23 and penetrates the fastening destination member 12 in the axial direction. is there.
The flow passage 24 opens toward the annular inclined surface 23.
The flow passage 24 extends radially outward from the thread of the screw 16 (described later). Therefore, in a state where the screw 16 is screwed into the female screw 22, a flow hole is defined by the screw 16 and the flow passage 24.
Further, the flow passage 24 is formed so that the screwing force of the screw 16 with respect to the female screw 22 can be secured in a state where the screw 16 (described later) is screwed into the female screw 22.
The flow passage 24 penetrates the fastening member 12 in the axial direction of the female screw 22.
Therefore, the flow passage 24 forms a flow passage between the seat surface 21 (specifically, the annular inclined surface 23) and the bottom portion 18.
At the bottom 18, the flow passage 24 has an opening 24a that opens outward in the housing 11.

The fastened member 14 is placed on the fastened member 12 in a state where the fastened member 14 is in contact with the seat surface 21 of the fastened member 12.
The member to be fastened 14 is fastened to the fastened member 12 by a screw 16 in a state of being placed on the seat surface 21 of the fastened member 12. In this state, the material to be fastened 14 closes the opening OP of the housing 11.
The material to be fastened 14 is formed in a flat plate shape so as to be able to close the opening OP of the housing 11, for example.
The material to be fastened 14 is provided with a mounting hole 28 at a position corresponding to the fastening member 12.
The mounting hole 28 is coaxial with the female screw 22 in a state of being in contact with the seat surface 21 of the fastening member 12.
The material to be fastened 14 is fastened to the seat surface 21 of the fastening member 12 by a screw 16 through which the mounting hole 28 is inserted.

The screw 16 has a screw portion 31 and a head portion 32.
By inserting the screw portion 31 through the mounting hole 28 and screwing it into the female screw 22, the material to be fastened 14 is sandwiched between the seat surface 21 and the head portion 32 of the fastening destination member 12.
In a state where the material to be fastened 14 is fastened to the seat surface 21, the mounting hole 28 of the material to be fastened 14 communicates with the flow passage 24 via the seat surface 21.
Specifically, the annular inclined surface 23 is formed in a conical shape on the opening edge of the female screw 22, and the outer circumference 23a of the annular inclined surface 23 is formed larger than the mounting hole 28.
Therefore, the mounting hole 28 of the member to be fastened 14 communicates with the annular inclined surface 23.
Further, the flow passage 24 is open to the annular inclined surface 23 and is opened at the bottom 18.

(Action)
In the screw fastening structure 10 of the first embodiment, the mounting hole 28 of the material to be fastened 14 is formed from a portion of the material to be fastened 14 that does not correspond to the flow passage 24 or a portion of the material to be fastened 14 that corresponds to the flow passage 24. Water droplets infiltrate the female screw 22 side through the above.
For example, in a portion of the material to be fastened 14 that does not correspond to the flow passage 24, water droplets penetrate into the female screw 22 side through the mounting hole 28 of the material to be fastened 14 as shown by arrow A (see FIG. 2).

For example, the outer circumference 23a of the annular inclined surface 23 is formed larger than the hole diameter of the mounting hole 28 against the intrusion of water droplets.
As a result, the screw fastening structure 10 can receive the infiltrated water droplets as shown by the arrow A on the annular inclined surface 23.
On the other hand, the annular inclined surface 23 communicates with the flow passage 24.
As a result, the water droplets received on the annular inclined surface 23 can be suitably guided to the flow passage 24 via the annular inclined surface 23 as shown by arrow B (see FIG. 1).
Further, the water droplets guided to the flow passage 24 can be discharged from the bottom 18 of the fastening member 12 to the outside of the housing 11 as shown by an arrow C (see FIG. 2) via the flow passage 24.

For example, when water droplets intrude into the female screw 22 side through the mounting hole 28 of the material to be fastened 14 as shown by arrow D (see FIG. 2) in the portion of the material to be fastened 14 corresponding to the flow passage 24, the infiltrated water droplets are discharged. It can be directly led to the flow passage 24.
Water droplets guided to the flow passage 24 can be discharged from the bottom 18 of the fastening member 12 to the outside of the housing 11 as shown by an arrow C (see FIG. 2) via the flow passage 24.
As a result, it is possible to prevent water droplets that have entered the female screw 22 side through the mounting holes 28 of the material to be fastened 14 from entering the inside of the housing 11 (that is, the inundation prohibited range) 35.

(effect)
According to the screw fastening structure 10 of the present embodiment, the position where the fastening destination member 12 and the screw 16 are provided is not limited to the peripheral edge of the housing 11.
Further, according to the screw fastening structure 10 of the present embodiment, it is not necessary to provide a waterproof structure between the head portion 32 of the screw 16 and the material to be fastened 14.
Therefore, it is possible to prevent the housing 11 and the head portion 32 of the screw 16 from becoming large.

As a comparative example, in a housing where water resistance is required, for example, the following screw fastening structure may be applied.
As a screw fastening structure of the first comparative example, a configuration is considered in which a screw is screwed to the outside of the waterproof packing provided in the housing to prevent water droplets from entering the water intrusion prohibited range in the housing by the waterproof packing. Be done.
As the screw fastening structure of the second comparative example, it is conceivable to fasten a screw with a waterproof seal to prevent water droplets from entering the water immersion prohibited range in the housing.
As the screw fastening structure of the third comparative example, it is conceivable that the head of the screw is sealed with caulking after the screw is fastened to prevent water droplets from entering the inundation prohibited range in the housing.

However, in the case of the first comparative example, in the case of the screw fastening structure in which the screws are screwed to the outside of the waterproof packing, the housing protrudes outward by the amount of the screws and becomes large.
Further, in the case of the second comparative example, when a screw with a waterproof seal is used, the head of the screw becomes large and the cost of the screw also increases.
Further, in the case of the third comparative example, when the head of the screw is sealed with caulking, a caulking treatment is required as an additional work after tightening the screw. For this reason, for example, when refastening a screw for maintenance, it is necessary to perform a caulking process again, and maintenance or the like requires a relatively long time.

On the other hand, in the present embodiment, as described above, the position where the fastening member 12 and the screw 16 are provided is not limited to the peripheral edge of the housing 11.
Therefore, in the present embodiment, it is possible to prevent the housing 11 from becoming larger than in the first comparative example.
Further, in the present embodiment, as compared with the second comparative example, it is not necessary to use a screw with a waterproof seal, the head 32 of the screw 16 can be suppressed from becoming large, and the cost increase of the screw 16 can be suppressed. be able to.
Further, in the present embodiment, as compared with the third comparative example, it is not necessary to seal the head 32 of the screw 16 with caulking for the purpose of preventing the intrusion of water droplets, and maintenance and the like do not take a long time. You can do it.

According to the present embodiment, the water droplets that have entered the female screw 22 side through the mounting hole 28 of the material to be fastened 14 are discharged from the flow passage 24 to the outside of the housing 11.
Therefore, for example, the place where the screw 16 is attached is not limited to the side portion of the fastening destination member 12 in a plan view, but can be attached to the center side of the fastening destination member 12.
As a result, the central side of the fastening member 12 can be suitably reinforced with the screw 16, and the strength of the fastening member 12 can be improved.

Hereinafter, the screw fastening structures of the second to fourth embodiments will be described with reference to FIGS. 3 to 7. In the screw fastening structures of the second to fourth embodiments, the same and similar members as those of the screw fastening structure 10 of the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

<Second embodiment>
As shown in FIGS. 3 and 4, the screw fastening structure 50 has an annular groove 52 formed on the seat surface 21 of the first embodiment, and other configurations are the same as those of the screw fastening structure 10 of the first embodiment. Is.
The annular grooves 52 are arranged at intervals outward in the radial direction with respect to the outer circumference 23a of the annular inclined surface 23, and are formed in an annular shape so as to be coaxial with the outer circumference 23a. The annular groove 52 communicates with the radial outer end of the flow passage 24.
In the present embodiment, the assembly unit 1 includes a screw fastening structure 50 instead of the screw fastening structure 10.

In the screw fastening structure 50 of the second embodiment, an annular groove 52 is formed on the seat surface 21 of the fastening destination member 12, and the annular groove 52 communicates with the flow passage 24.
For example, water droplets that have passed through the mounting holes 28 of the material to be fastened 14 have penetrated between the back surface of the material to be fastened 14 and the seating surface 21 as shown by arrow E (see FIG. 4) due to a capillary phenomenon. Water droplets can be received in the annular groove 52.
Therefore, the water droplets received in the annular groove 52 can be guided to the flow passage 24 through the annular groove 52 and discharged from the flow passage 24 to the outside of the housing 11.
Therefore, it is possible to prevent water droplets that have entered between the back surface of the material to be fastened 14 and the seat surface 21 due to the capillary phenomenon from entering the inside of the housing 11 (that is, the inundation prohibited range) 35.

According to the screw fastening structure 50 of the present embodiment, the position where the fastening destination member 12 and the screw 16 are provided is not limited to the peripheral edge of the housing 11.
Further, according to the screw fastening structure 50 of the present embodiment, it is not necessary to provide a waterproof structure between the head portion 32 of the screw 16 and the material to be fastened 14.
Therefore, it is possible to prevent the housing 11 and the head portion 32 of the screw 16 from becoming large.

Further, according to the screw fastening structure 50 of the present embodiment, the cost increase of the screw 16 can be suppressed as in the screw fastening structure 10 of the first embodiment.

Further, according to the screw fastening structure 50 of the present embodiment, it is necessary to seal the head 32 of the screw 16 with caulking for the purpose of preventing the intrusion of water droplets, as in the screw fastening structure 10 of the first embodiment. It is possible to perform maintenance without spending a long time.

<Third Embodiment>
As shown in FIGS. 5 and 6, the screw fastening structure 60 has the fastening destination member 12 of the second embodiment replaced with the fastening destination member 62, and the other configurations are the screw fastening structure 50 of the second embodiment. The same is true. The fastening member 62 is a fastening member including a bulging portion 63 in the fastening member 12 of the second embodiment, and is a fastening member in which the flow passage 24 of the second embodiment is replaced with the flow passage 65.
Other configurations of the fastening member 62 are the same as those of the fastening member 12 of the second embodiment.
In the present embodiment, the assembly unit 1 includes a screw fastening structure 60 instead of the screw fastening structure 10.

The screw fastening structure 60 includes a fastening member 62, a member to be fastened 14, and a screw 16 for fastening the member to be fastened to the fastening member 62.
The fastening member 62 includes a seat surface 21 and a female screw 22.
The fastening member 62 has a flow passage 65.
For example, the fastening member 62 may have an annular inclined surface 23.
The flow passage 65 has a flow hole 66 and a communication groove 67.
The flow passage 65 penetrates the housing 11 in the axial direction of the female screw 22.

The bulging portion 63 is a portion of the outer circumference of the fastening destination member 62 in which a part in the circumferential direction is bulged outward in the radial direction and extends in the vertical direction along the outer circumference of the fastening destination member 62. is there.
A flow hole 66 of the flow passage 65 is formed in the bulging portion 63.
The bulging portion 63 extends in the axial direction of the female screw 22 so as to define the flow hole 66 on the outside of the female screw 22.
The bulging portion 63 has an arc shape in a plan view.

The flow hole 66 has a flow groove that penetrates the fastening member 62 in the axial direction.
The upper part of the flow hole 66 is opened to the seat surface 21, and the lower part is opened to the bottom 18.

The communication groove 67 is formed in a concave shape that opens upward on the seat surface 21, and extends in the radial direction. The communication groove 67 is opened in a part of the female screw 22, a part of the annular inclined surface 23, a part of the annular groove 52, and the upper part of the flow hole 66.
That is, the upper portion of the flow hole 66 is communicated with the female screw 22, the annular inclined surface 23, and the annular groove 52 via the communication groove 67.
Since the flow hole 66 is defined by the bulging portion 63, it is not necessary to form the flow hole 66 in the female screw 22. As a result, the screwing force of the screw 16 with respect to the female screw 22 can be secured in the state where the screw 16 is screwed into the female screw 22.

Further, in the screw fastening structure 60 of the present embodiment, the flow passage 65 includes a flow hole 66 and a communication groove 67.
Further, the flow passage 65 penetrates the housing 11 in the axial direction of the female screw 22.
The flow hole 66 communicates with the communication groove 67.
The communication groove 67 communicates with the female screw 22, the annular inclined surface 23, and the annular groove 52.
That is, the flow hole 66 communicates with the female screw 22, the annular inclined surface 23, and the annular groove 52 via the communication groove 67.
As a result, the water droplets that have entered the female screw 22 side through the mounting hole 28 of the material to be fastened 14 are guided to the flow hole 66 through the annular inclined surface 23 and the communication groove 67, and are discharged from the flow hole 66 to the outside of the housing 11. Will be done.
Therefore, the screw fastening structure 60 can prevent water droplets that have entered the female screw 22 side through the mounting holes 28 of the material to be fastened 14 from entering the inside of the housing 11 (that is, the water intrusion prohibition range) 35.

For example, when water droplets that have passed through the mounting holes 28 of the material to be fastened 14 have infiltrated between the back surface of the material to be fastened 14 and the seating surface 21 due to a capillary phenomenon, the infiltrated water droplets may be received by the annular groove 52. it can.
The water droplets received in the annular groove 52 are guided to the flow hole 66 via the annular groove 52 and the communication groove 67, and are discharged from the circulation hole 66 to the outside of the housing 11.
As a result, it is possible to prevent water droplets that have entered between the back surface of the material to be fastened 14 and the seat surface 21 due to the capillary phenomenon from entering the inside of the housing 11 (that is, the inundation prohibited range) 35.

According to the screw fastening structure 60 of the present embodiment, the position where the fastening destination member 62 and the screw 16 are provided is not limited to the peripheral edge of the housing 11.
Further, according to the screw fastening structure 60 of the present embodiment, it is not necessary to provide a waterproof structure between the head portion 32 of the screw 16 and the material to be fastened 14.
Therefore, it is possible to prevent the housing 11 and the head portion 32 of the screw 16 from becoming large.

Further, according to the screw fastening structure 60 of the present embodiment, it is possible to suppress an increase in the cost of the screw 16 as in the screw fastening structure of the first embodiment and the second embodiment.

Further, according to the screw fastening structure 60 of the present embodiment, the head portion 32 of the screw 16 is sealed by caulking for the purpose of preventing the intrusion of water droplets, as in the screw fastening structure of the first embodiment and the second embodiment. It is not necessary to do so, and maintenance can be performed without spending a long time.

<Fourth Embodiment of the minimum configuration of the screw fastening structure 10>
A fourth embodiment of the minimum configuration of the screw fastening structure 10 will be described with reference to FIG.
The screw fastening structure 10 includes a member to be fastened 14, a fastening member 12, and a screw 16.
The material to be fastened 14 is provided with a mounting hole 28.
The fastening member 12 includes a female screw 22 coaxial with the mounting hole 28.
The fastening member 12 has a flow passage 24 that opens into the seat surface 21 with which the material to be fastened 14 abuts and penetrates the housing 11 in the axial direction of the female screw 22.
The screw 16 is screwed into the female screw 22 through the mounting hole 28, so that the material to be fastened 14 is sandwiched between the head 32 together with the fastening member 12.

In the screw fastening structure 10 of the present embodiment, the flow passage 24 penetrates the housing 11 in the axial direction of the female screw 22 of the fastening destination member 12.
Further, the flow passage 24 is opened in the seat surface 21 with which the material to be fastened 14 is in contact.
Therefore, in a state where the screw 16 is screwed into the female screw 22 and the material to be fastened 14 is sandwiched between the head 32 and the fastening member 12, the mounting hole 28 of the fastening member 14 is seated on the fastening member 12. It can communicate with the flow passage 24 via the surface 21.
Therefore, the water droplets that have entered the female screw 22 side through the mounting hole 28 of the material to be fastened 14 can be guided to the flow passage 24 and discharged from the flow passage 24 to the outside of the housing 11.

For example, the assembly unit may include a screw fastening structure 10 and a housing 11.

According to the screw fastening structure 10 of the present embodiment, the position where the fastening destination member 12 and the screw 16 are provided is not limited to the peripheral edge of the housing 11.
Further, according to the screw fastening structure 10 of the present embodiment, it is not necessary to provide a waterproof structure between the head portion 32 of the screw 16 and the material to be fastened 14.
Therefore, it is possible to prevent the housing 11 and the head portion 32 of the screw 16 from becoming large.

Further, according to the screw fastening structure 10 of the present embodiment, it is possible to suppress an increase in the cost of the screw 16.

Further, according to the screw fastening structure 10 of the present embodiment, it is not necessary to seal the head of the screw 16 with caulking for the purpose of preventing the intrusion of water droplets, and maintenance and the like can be performed without spending a long time. it can.

Although the embodiment of the present invention has been described above, this embodiment is shown as an example and is not intended to limit the scope of the invention. This embodiment can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. This embodiment and its modifications are included in the scope and gist of the invention, as well as in the scope of the invention described in the claims and the equivalent scope thereof.

For example, in the above-described embodiment, an example in which one flow passage 24 is formed in the fastening member 12 and an example in which one flow passage 65 is formed in the fastening member 62 have been described, but as another example, the flow passage is used. A plurality may be formed.
For example, in the above-described embodiment, an example in which one annular groove 52 is formed in the fastening destination member 12 has been described, but as another example, a plurality of annular grooves may be formed.

1 Assembly unit 10 Screw fastening structure 11 Housing 12 Fastening member 14 Fastening material 16 Screw 18 Bottom 21 Seat surface 22 Female screw 23 Circular inclined surface 23a Outer circumference 24 Flow passage (distribution groove)
24a Opening 28 Mounting hole 31 Threaded part 32 Head 35 Internal 50 Threaded fastening structure 52 Circular groove 60 Screwed fastening structure 62 Fastening member 63 Protruding part 65 Flow passage 66 Flow hole 67 Communication groove OP Opening

Claims (6)

The material to be fastened with mounting holes and
A fastening member having a female screw coaxial with the mounting hole and having a flow passage that opens in a seat surface with which the material to be fastened abuts and penetrates the housing in the axial direction of the female screw.
A screw fastening structure including a screw for sandwiching the material to be fastened with a head together with the fastening destination member by inserting the mounting hole and screwing the female screw. The screw fastening structure according to claim 1, wherein the flow passage is a distribution groove in which the female screw is cut out radially outward. The flow path is
A flow hole that penetrates in the axial direction on the outside of the female screw,
The screw fastening structure according to claim 1, further comprising a communication groove provided in the bearing surface so that the flow hole communicates with the female screw. The screw fastening structure according to any one of claims 1 to 3, wherein the fastening destination member is formed on the opening edge of the female screw and has a conical annular inclined surface having an outer diameter larger than the hole diameter of the mounting hole. The fastening member is
The screw fastening structure according to claim 4, wherein the seat surface is formed in an annular shape on the outside of the annular inclined surface and has an annular groove communicating with the flow passage. The screw fastening structure according to any one of claims 1 to 5.
With the above housing
Assembly unit with.

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