JP5993814B2 - Wiring pull-in structure - Google Patents

Description

  The present invention relates to a wiring lead-in structure used when drawing an external wiring to be connected to an electric device such as a camera into a housing such as an explosion-proof container.

  There is an explosion-proof camera in which a surveillance camera for monitoring the inside of a hazardous area is housed in an explosion-proof container as a device for housing electrical equipment inside a housing. For the explosion-proof container, a wiring lead-in structure for drawing an external wiring such as a power cable for supplying power to a camera as an electric device or a video cable for outputting a video signal to the outside of the housing is used.

  As a conventional wiring drawing-in structure, there is one provided with a drawing-in tool attached to a through-hole formed in a main body (for example, see Patent Document 1). The retraction instrument is a hollow cylindrical nipple that is screwed into one end of a screw hole formed in the container, a hollow cylindrical socket that is externally fitted to the wiring and is fitted into the nipple from the other end of the nipple, And a movement restricting member that is screwed into the nipple from the other end side of the nipple and presses the socket in the axial direction so that the flange portion of the socket comes into contact with the stepped portion inside the nipple. A clamp plate mounting portion for sandwiching the wiring is formed in the socket, and the compound is filled in the socket that is externally fitted to the wiring.

  With this configuration, while ensuring the explosion-proof function required for wiring retractors used in containers containing electrical equipment in hazardous areas, it is possible to simplify work and reduce work costs when replacing wiring. It is supposed to be possible.

JP 09-261823 A

  However, in the conventional wiring lead-in structure, since the retracting device is composed of a large number of parts, there are problems that the cost of the parts increases and the operation of attaching the retracting device to the container becomes complicated.

  An object of the present invention is to provide a wiring lead-in structure capable of realizing cost reduction and easy installation work by reducing the number of parts.

  The wiring lead-in structure of the present invention is a wiring lead-in structure that draws external wiring into a housing that houses electrical equipment, and includes a mounting portion, an elastic body, a pull-in device, and a regulating member. The mounting portion is a storage portion that is disposed on a part of the wall surface of the housing and penetrates the wall surface, and has a storage portion having a small diameter portion on the inner side of the housing. The elastic body has a hole portion that fits into the storage portion and extends along the penetration direction of the storage portion, and expands the area of the cross section perpendicular to the penetration direction when a compressive force is applied along the penetration direction. The retracting device includes an insertion portion that is movably inserted into the storage portion along the penetration direction, and a hollow portion that penetrates along the penetration direction and communicates with the hole portion. The restricting member restricts the movement of the retracting device to the outside of the housing in the penetration direction.

  According to this configuration, when the wiring is sequentially passed through the hollow portion of the retracting device and the hole of the elastic body, and then the elastic body and the insertion portion of the retracting device are inserted into the storage portion, the elastic body inserted into the storage portion is In the state where movement in the penetrating direction is restricted by the small diameter portion, the area of the cross section orthogonal to the penetrating direction is increased by being pressed in the penetrating direction by the insertion portion, the outer surface is brought into close contact with the inner side surface of the storage portion, and the hole portion Hold the wiring on the inner surface. Airtightness and watertightness inside the housing are realized at the insertion position of the elastic body in the storage portion. By restricting the movement of the retractable device to the outside of the housing in the penetration direction of the retracting device, the airtightness and watertightness inside the housing are maintained.

  In this configuration, the insertion portion preferably has a clamp portion that exposes a part of the hollow portion and clamps the wiring. By restricting the movement of the wiring in the penetration direction, it is possible to reliably maintain the airtightness and watertightness inside the housing at the position of the storage portion.

Moreover, the insertion part has the said clamp part in the position which opposes the inner surface of a storage part, and a wiring drawing-in structure is a part of the penetration direction in the outer surface of an insertion part outside a clamp part about a penetration direction. It is preferable to further include a seal member that seals between the inner surface of the storage unit and the inner surface of the storage unit. It is possible to prevent moisture that has entered from between the retracting device and the storage portion from flowing into the external cable protection tube connected to the retracting device via the clamp portion.

  According to the present invention, it is possible to reduce the number of parts and facilitate the mounting work while maintaining the airtightness and watertightness of the wiring drawing-in portion with respect to the inside of the housing.

1 is an external view of an explosion-proof camera to which a wiring lead-in structure according to an embodiment of the present invention is applied. It is an assembly drawing of the explosion-proof camera. It is sectional drawing of the principal part of the explosion-proof camera.

  Hereinafter, a wiring lead-in structure according to an embodiment of the present invention when applied to an explosion-proof camera will be described with reference to the drawings.

  As shown in FIGS. 1 and 2, the wiring lead-in structure according to the embodiment of the present invention is applied to an explosion-proof camera 100 as an example. The explosion-proof camera 100 houses a camera module 20 that is an electric device of the present invention in an explosion-proof container 10 on the assumption that an image of a dangerous area is imaged.

  The explosion-proof container 10 corresponds to the casing of the present invention, and includes a main body 11, a lid body 12, a lid body 13, and a mounting portion 14. The main body 11 has a substantially cylindrical shape as an example, and both end surfaces in the axial direction are open, and are respectively formed as a front side opening 11A and a back side opening 11B. The front side opening 11A and the back side opening 11B are provided with female screw portions 111 and 112, respectively, and can be opened and closed by screwing the screw portions 122 and 132 of the lid body 12 and the lid body 13 together. The lid 12 has a hole 121 covered with a transparent member such as tempered glass at the center.

  For example, the mounting portion 14 extends in the radial direction of the main body 11 from the back side of the peripheral surface of the main body 11. Each of the mounting portions 14 allows the wiring to the camera module 20 to pass through along the penetration direction X by a retracting device 141 mounted on the bottom surface via a tightening screw 142.

  The camera module 20 includes a camera 21, a plate 22, a holder 23, a circuit board 24, a circuit board 25, and a connection tool 26. The camera 21 is mounted on the plate 22 together with the circuit boards 24 and 25. The plate 22 is constituted by a flat plate made of a heat conductive material as an example. The circuit boards 24 and 25 are mounted with electronic parts for supplying power to the camera 21 and for signal processing.

  The holder 23 has a substantially U-shape as an example, and a plate 22 with a camera 21 attached to the front side is attached via screws 221 and a connection tool 26 is attached to the back side. The connection tool 26 is electrically connected to the electronic components of the circuit boards 24 and 25 and is connected to the wiring penetrating the mounting portion 14.

  The camera module 20 is inserted from the rear side into the explosion-proof container 10 through the front opening 11 </ b> A opened with the lid 12 removed, and is connected to the explosion-proof container via a fixing screw that passes through the mounting hole 232 of the holder 23. 10 is fixed at a predetermined position.

  As shown in FIG. 3, the mounting portion 14 has a first storage portion 143 and a second storage portion 144 that penetrate the side surface of the explosion-proof container 10 along a penetration direction X from the outside to the inside of the explosion-proof container 10. The large storage portion 143 is formed inside. As for the 1st accommodating part 143, the inner side of the explosion-proof container 10 is made into the small diameter part 1431. FIG. The second storage part 144 has a larger diameter than the first storage part 143.

  An annular elastic body 145 is fitted into a portion of the first storage portion 143 excluding the small diameter portion 1431. The elastic body 145 has a hole 1451 that is open along the penetration direction X. When the elastic body 145 is compressed along the penetration direction X, the area of the cross section orthogonal to the penetration direction X is expanded. The retracting device 141 is fitted into the second storage portion 144.

  The retracting device 141 includes a pressing portion 1411, a fitting portion 1412, a hollow portion 1413, a seal portion 1414, and a clamp portion 1415. The pressing portion 1411 has an outer diameter equal to the inner diameter of the first storage portion 143 and is positioned inside the fitting portion 1412 in the penetration direction X.

  The fitting portion 1412 has an outer shape equal to the inner diameter of the second storage portion 144 and has the same length as the second storage portion 144 in the penetration direction X. The hollow portion 1413 penetrates the retracting device 141 along the penetration direction X. The seal portion 1414 is formed on a part of the outer peripheral surface of the fitting portion 1412, and the seal member 1416 is fitted outside. The seal member 1416 seals between the inner peripheral surface of the second storage portion 144 and the outer peripheral surface of the fitting portion 1412.

  The clamp portion 1415 is formed by exposing a part of the hollow portion 1413 inside the seal portion 1414 in the penetration direction X. As shown in FIG. 2, a clamp plate 1417 is attached to the clamp portion 1415. The clamp plate 1417 holds the wiring between the inner peripheral surface of the hollow portion 1413.

  After the elastic body 145 is inserted into the first storage portion 143 and then the insertion portion 1412 of the retracting device 141 is inserted into the second storage portion 144, the pressing portion 1411 enters the first storage portion 143. And abuts against the elastic body 145. The elastic body 145 is restricted from moving inward along the penetration direction X by the contact of the small diameter portion 1431 and the stepped portion 1432 in the first storage portion 143, and is pressed by the pressing portion 1411.

  The elastic body 145 is compressed along the penetration direction X by being pressed by the pressing portion 1411, and expands the area of the cross section orthogonal to the penetration direction X. Since the outer diameter of the elastic body 145 is equal to the inner diameter of the first storage portion 143, the elastic body 145 reduces the inner diameter of the hole portion 1451 in a state where the outer peripheral surface is in close contact with the inner peripheral surface of the first storage portion 143. The wiring located in the hole 1451 is sandwiched. The interior of the explosion-proof container 10 is brought into an airtight state and a watertight state by the elastic body 145 at the position of the first storage portion 143.

  Since the wiring is clamped by the clamp plate 1417 at the clamp portion 1415 of the retracting device 141, the movement in the direction along the penetration direction X is restricted. An airtight state and a watertight state by the elastic body 145 at the position of the first storage portion 143 are maintained.

  In the clamp portion 1415, the wiring is exposed from the retracting device 141, but a seal member 1416 fitted around the seal portion 1414 is disposed outside the clamp portion 1415 in the penetration direction X, and the inner circumference of the second storage portion 144 is arranged. The space between the surface and the outer peripheral surface of the insertion portion 1412 is sealed. For this reason, moisture that has entered from between the retracting device 141 and the second storage portion 144 flows into the external cable protection tube connected to the retracting device 141 via the clamp portion 1415 and the hollow portion 1413. Can be prevented.

  As shown in FIG. 2, the retracting instrument 141 is fixed to the bottom surface of the mounting portion 14 by a fastening screw 142, so that the movement toward the outside along the penetration direction X is restricted, and in the second storage portion 144. The position in the penetration direction X is fixed. The tightening screw 142 corresponds to the regulating member of the present invention. The pressing state of the elastic body 145 by the pressing portion 1411 is continued, and the confidentiality and water tightness inside the explosion-proof container 10 are maintained.

  The elastic body 145, the pressing portion 1411, and the fitting portion 1412 need only be movable along the penetration direction X in the first storage portion 143 and the second storage portion 144, and do not need to rotate. The portion 143, the second storage portion 144, the elastic body 145, the pressing portion 1411, and the fitting portion 1412 are not necessarily formed in a circular cross-sectional shape.

  Also, the inner diameter of the first storage part 143, the inner diameter of the second storage part 144, the outer diameter of the elastic body 145, the outer diameter of the pressing part 1411, and the outer diameter of the fitting part 1412 can be made equal to each other. In this case, in the retracting device 141, the pressing portion 1411 and the insertion portion 1412 are continuous, and it is not necessary to distinguish the two.

  Further, the retractable device 141 may be fixed to the mounting portion 14 by screwing the external thread portion formed in the retractable device 141 into the internally threaded portion formed in the second storage portion 144.

  In addition, the housing of the present invention is not limited to the explosion-proof container 10. The present invention can be applied to an arbitrary housing into which external wiring is to be drawn while maintaining airtightness or watertightness.

10-explosion-proof container 14-mounting part 141-retraction device 142-clamping screw (regulating member)
143-first storage portion 144-second storage portion 145-elastic body 1412-insertion portion 1413-hollow portion 1431-small diameter portion 1451-hole portion

Claims (2)

A wiring lead-in structure that draws external wiring into the housing of the electrical equipment,
A mounting portion that is disposed on a part of the wall surface of the housing and that is a storage portion that penetrates the wall surface and that has a storage portion having a small diameter portion on the inner side of the housing;
An elastic body that fits into the storage portion, has a hole portion that penetrates along the penetration direction of the storage portion, and has a cross-section orthogonal to the penetration direction when a compressive force acts along the penetration direction. An elastic body that expands the area;
A fitting portion for movably fitted along said penetration direction to the housing part, the a hollow portion which penetrates along the penetrating direction have a, a hollow portion communicating with the hole portion, the fitting portion A retracting device having a clamp part that exposes a part of the hollow part and sandwiches the wiring at a position facing the inner surface of the storage part ;
A regulating member that regulates movement of the housing in the penetration direction to the outside of the housing;
A seal member that seals between a part of the penetration direction on the outer side surface of the fitting portion and the inner surface of the storage portion outside the clamp portion with respect to the penetration direction;
Wiring lead-in structure with Wherein the housing, the wiring lead-structure according to claim 1 which is anti爆容device.

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