JP7471833B2 - Cable clamp device and its manufacturing method - Google Patents

Description

An embodiment of the present invention relates to a cable clamp device and a manufacturing method thereof.

Cable clamp devices are widely used in all types of equipment that has cables. For example, in explosion-proof camera devices, which are a type of surveillance camera, cable clamp devices are used to secure the cables connected to them. Explosion-proof camera devices are used in environments where hazardous materials are handled, such as petrochemical plants, and the images captured by the explosion-proof camera device are transmitted via cable to a monitor room or via a network to a server, etc.

It is desirable for a cable clamping device to be able to maintain the cable in a fixed position even when a strong pulling force is applied to the connected cable.

JP 2005-537087 A JP 2006-187107 A

According to one embodiment, the objective is to provide a cable clamping device and a manufacturing method thereof that can maintain high clamping strength against the pulling force of the cable.

In order to solve the above problem, a clamp device according to an embodiment includes a first fitting having a semi-cylindrical first cable fastening groove formed on one surface thereof, and a second fitting having a semi-cylindrical second cable fastening groove formed on one surface thereof. The first fitting further includes a third cable fastening groove spaced apart from the first cable fastening groove, and the second fitting further includes a fourth cable fastening groove spaced apart from the second cable fastening groove. The first cable fastening groove and the second cable fastening groove comprise parts of a thread groove structure formed by thread processing , and the third cable fastening groove and the fourth cable fastening groove comprise parts of a thread groove structure formed by thread processing. Furthermore, a depth of the first cable fastening groove on the one surface of the first fitting is different from a depth of the third cable fastening groove, and a depth of the second cable fastening groove on the one surface of the second fitting is different from a depth of the fourth cable fastening groove. The configuration includes a mechanism for combining the first metal fitting and the second metal fitting in either a first state in which the first cable fixing groove and the second cable fixing groove face each other and the third cable fixing groove and the fourth cable fixing groove face each other, or a second state in which the first cable fixing groove and the fourth cable fixing groove face each other and the third cable fixing groove and the second cable fixing groove face each other.

1 is an external view of an explosion-proof camera device according to an embodiment; 2 is a front view and a side view of the explosion-proof camera device of FIG. 1 . 1A and 1B are a configuration diagram and a cross-sectional view of a cable clamp device according to an embodiment. 1 is a cross-sectional view illustrating a state in which a cable clamp device according to an embodiment is used. 5A to 5C are manufacturing process diagrams (perspective views) showing processes for manufacturing the first fitting and the second fitting of the cable clamp device according to the embodiment. 5A to 5C are manufacturing process diagrams (top views) showing processes for manufacturing the first fitting and the second fitting of the cable clamp device according to the embodiment. FIG. 4 is a perspective view showing a state in which a block used in the cable clamp device according to the embodiment is cut.

The following describes the embodiment with reference to the drawings.

Figure 1 is an external view of an explosion-proof camera device to which one embodiment is applied. Figure 2 is a front view and a side view of the explosion-proof camera device of Figure 1. The explosion-proof camera device 100 has a cylindrical central case 101, a head case 102, and a rear cover 104. An anti-fogging glass 103 is fitted into the front opening of the head case 102.

A nut 105 is screwed into the mounting portion provided in the center of the rear cover 104 to secure the cable outlet 105 to the rear cover 104. A cable clamp device 300, which will be described below, is placed in the space inside this nut 105.

Figure 3(a) shows one embodiment of a cable clamp device 300. In the figure, 310 is a first fitting and 320 is a second fitting.

The first metal fitting 310 is formed by processing a first member having a certain thickness, and of the other surface (upper surface) 311 and one surface (lower surface) 312 that face each other when the first member is viewed from the front, the first metal fitting 310 is recessed from the one surface (lower surface) 312 at a distance from the one surface (lower surface) 312, and forms a cable fixing groove H1 and a cable fixing groove H2 extending from the front to the rear. The cable fixing groove H1 and the cable fixing groove H2 are each semicircular. Here, semicylindrical refers to a state in which a cylinder is cut at a plane perpendicular to the bottom surface, and the cross-sectional shape parallel to the bottom surface is semicircular or arched.

The inner surfaces of the cable fixing groove H1 and the cable fixing groove H2 are provided with parts R1 and R2 of a screw structure formed by thread machining that draws a spiral in the axial direction. The parts R1 and R2 of this screw structure have a trapezoidal shape at the protruding tip on the inner diameter side.

Furthermore, it has a through hole 313 formed from the middle part (between the grooves) of the other surface (upper surface) 311 toward the middle part of the one surface 312.

A second metal fitting 320 is prepared to be paired with the first metal fitting 310. This second metal fitting 310 has one surface (upper surface) 323 and the other surface (lower surface) 324 that face each other when the second member having thickness is viewed from the front, and is recessed from the one surface (upper surface) 323 at a distance from the one surface (upper surface) 323, forming cable fixing grooves H3 and H4 from the front to the rear. The cable fixing grooves H3 and H4 are each semicircular in shape and face the cable fixing grooves H1 and H2 mentioned above. Here, the semicylindrical shape refers to a state in which a cylinder is cut at a plane perpendicular to the bottom surface, and the cross-sectional shape parallel to the bottom surface is semicircular or arched.

The inner surfaces of cable fixing groove H3 and cable fixing groove H4 also have parts R3 and R4 of a screw structure formed by thread machining that draws a spiral in the axial direction. The protruding tips of the parts R3 and R4 of the screw structure on the inner diameter side are also trapezoidal in shape and are not sharp.

Furthermore, it has a screw hole 325 formed within the thickness from the middle part (between the grooves) of one surface (upper surface) 323 to the middle part of the other surface (lower surface) 324.

Furthermore, the other surface (upper surface) 311 of the first fitting 310 forms a curved surface 311R recessed toward the other surface 312. A washer 411 is placed on this curved surface 311R, and the screw 412 is threaded into the screw hole 325 via the through hole 313 using this washer 411. The surface of the washer 411 facing the curved surface 311R is also curved to fit the curved surface 311R.

As a result, the first metal fitting 310 and the second metal fitting 320 can be fastened and fixed by the screw 412. The first metal fitting 310 and the second metal fitting 320 form a pair and can clamp the cable 200 by the cable fixing grooves H1-H4.

In the above configuration, the first metal fitting 310 is formed with a cable fixing groove H1 and a cable fixing groove H2, each recessed and spaced apart. The second metal fitting 320 is formed with a cable fixing groove H3 and a cable fixing groove H4, each recessed and spaced apart.

In this case, various combination patterns of the depths of the recesses of each of the grooves H1 to H4 are possible. The depths of all the recesses of the grooves H1 to H4 may be the same or different. Alternatively, two grooves of the same depth may be combined. Furthermore, for example, when grooves H1 and H3 face each other with a gap between them, a first circle is formed, and when grooves H2 and H4 face each other with a gap between them, a second circle is formed, but the centers of the first and second circles may be shifted (offset) toward the surface 311 and the surface 324 (details will be described in Figures 5 and 6).

3(b) is an explanatory diagram taken out to explain the effect of the structure of the cable clamp device 300 described above. In the figure, the cable fixing groove H1 is taken out and shown. Now, assume that a force F1 acts in the axial direction of the cable fixing groove H1, pulling the cable 200 strongly. Then, in this device, the axial force F1 acting from the cable 200 to the first metal fitting 310 is dispersed in the directions of forces f2 and f3. This is because parts R1 and R3 of the screw structure that draw a spiral in the axial direction are formed on the inner surface of the cable fixing groove H1. The inclination of the parts R1 and R3 of the screw structure distributes the force F1, and as a result, all of the force pulling the cable is prevented from being directly concentrated and applied only to the clamp device 300. In other words, the force F1 is not distributed, and 100% of the force F1 is not always applied to the clamp device 300. If force F1 were not distributed and 100% of force F1 were applied to clamp device 300, it could cause the cable to shift in the axial direction, be pulled out, and even have a direct effect on the holding member that holds clamp device 300, making the entire device more susceptible to failure and deterioration of durability. With this clamp device, axial displacement of the cable, cable pull-out, failure, and deterioration of durability are reduced.

In addition, some of the threaded structures R1 to R4 have trapezoidal protruding tips on the inner diameter side. This makes it less likely that the threaded structure will damage the acrylic cable sheath, for example. This further strengthens the cable fastening strength and improves the cable retention force.

In the above embodiment, the first metal fitting 310 and the second metal fitting 320 can clamp two cables, but the device may clamp only one cable. In that case, one cable fixing groove is formed in the first metal fitting 310, and one cable fixing groove is formed in the second metal fitting 320. Of course, even with such a configuration, the above-mentioned effects can be obtained. In this case, the structure for fastening the first metal fitting 310 and the second metal fitting 320 together is not limited to the above embodiment, and various embodiments are possible. For example, a cable fixing groove may be provided in the center of the first metal fitting 310 and the second metal fitting 320 (where the screw 412 is located), and a screw tightening portion may be configured on the left and right of the groove (where the grooves H1, H3 and the grooves H2, H4 are located).

4(a) to 4(d) are diagrams for further explaining an example of the use state of the cable clamp device 300. In the example of FIG. 4(a), the groove H4 on one surface (upper surface) 323 of the second metal fitting 320 faces the cable fixing groove H1 on the other surface 312 formed on the first metal fitting 310, and the groove H3 on one surface (upper surface) 323 of the second metal fitting 320 faces the cable fixing groove H2. The figure shows a state in which the cable 200a is clamped between the cable fixing groove H1 and the groove H4, and the cable 200b is clamped between the cable fixing groove H2 and the groove H3. Naturally, in this case, the screw 412 tightens the first metal fitting 310 and the second metal fitting 320 via the washer 411, and accordingly the cables 200a and 200b are clamped. The cables 200a and 200b are laid inside the armored cable 200 shown in FIG. 1.

In the above-mentioned state, the cable fixing groove H1 and the fourth groove H4, which have a deep recess, can clamp the cable 200a with a large diameter, and the cable fixing groove H2 and the third groove H3, which have a shallow recess, can clamp the cable 200b with a small diameter.

Figure 4(b) is a cross-sectional view of Figure 4(a). In Figure 4(b), 500 is a cable-passing fitting, and the portion through which the cable passes has a hole in the axial direction, and a packing 712 is placed to fill the gap between the hole and the cable. This cable-passing fitting 500 is inserted in the axial direction into the cylindrical bearing portion 104a of the lid 104. In this case, the cable-passing fitting 500 engages with the claw 104b of the bearing portion 104a of the lid 104 so as not to rotate freely.

The cable-passing fitting 500 also has an engagement portion 501 formed on the surface where the first fitting 310 and the second fitting 320 of the clamp device 300 come into contact, allowing the first fitting 310 and the second fitting 320 to fit into each other. This prevents the entire clamp device 300 from rotating around its axis.

The nut 105 is screwed onto the threaded portion formed on the outer periphery of the cylindrical portion 104 of the lid 104. As a result, the clamp device 300 is pressed by a part of the nut 105 via the buffer packing 713, and the positioning state is stabilized.

Figure 4(c) shows the state where the third groove H3 of the second fitting 320 faces the cable fixing groove H1 of the first fitting 310, and the fourth groove H4 of the second fitting 320 faces the cable fixing groove H2. In this way, with this device, grooves that can be effectively clamped can be combined and used depending on the diameter of the cables 200c and 200d. At this time, even if the inclination of the first fitting 310 relative to the second fitting 320 changes, the washer 411 and the curved surface 311R fit freely, and the first fitting 310 and the second fitting 320 can be tightened and fixed by the screw 412.

In this embodiment, the fastening means for fastening the first fitting 310 and the second fitting 320 is configured such that the screw 412 passes through the through hole 313 and is screwed into the screw hole 325. The fastening means illustrated in this embodiment has a simple structure that can be implemented at low cost. However, the fastening means is not limited to this configuration, and various forms are possible. For example, the fastening means may be configured to bite the other surface 311 of the first fitting 310 with an upper jaw member and the other surface 324 of the second fitting 320 with a lower jaw member, so that the first fitting 310 and the second fitting 320 are clamped together, or multiple fastening means may be used.

The structure of this embodiment is suitable for clamping multiple cables of different thicknesses (diameters). Figure 4(a) shows the relationship in which the cable fixing grooves H1 (deep groove) and H2 (shallow groove) of the first metal fitting 310 face the cable fixing grooves H4 (deep groove) and H3 (shallow groove) of the second metal fitting 320, respectively, while Figure 4(n) shows the relationship in which the cable fixing grooves H1 (deep groove) and H2 (shallow groove) of the first metal fitting 310 face the cable fixing grooves H4 (shallow groove) and H3 (deep groove) of the second metal fitting 320, respectively. By changing the orientation of the metal fittings in this way, it is possible to combine grooves of suitable depths for clamping cables, and this cable clamp device is versatile, easy to use, and highly useful.

Figure 4(d) shows the cable-passing fitting 500 as seen from the front, with cable-passing holes 511, 512 of fixed diameter, and behind these holes can be placed packings 711, 712 whose inner diameter can be adjusted according to the thickness of the cable.

The above configuration provides the same effects as the first embodiment, and is easy to use as it can be used to clamp cables of various diameters, and it is less likely to damage the cable insulation, and it can increase the tensile strength.

Figures 5(a) to 5(d) and 6(a) to 6(c) are explanatory diagrams showing an example of a process for manufacturing the first fitting 310 and the second fitting 320. Figures 5(a) to 5(d) and 6(a) to 6(c) show the front and back relationship of the first fitting 310 and the second fitting 320 shown in Figure 3 in reverse.

Figure 5 (a) shows the first and second members 310 and 320 in an integrated state before processing, and shows the metal member 390 before the metal is processed. The metal member 390 is, for example, a rectangular block having long sides 39a, 39b and short sides 39c, 39d. To make the explanation easier to understand, the pre-processed member 390 is shown as a flat plate having a thickness, but it is not necessarily limited to this shape. The relationship between the long and short sides is also not necessarily required. Furthermore, in the explanation, an example of manufacturing one clamp device 300 is described, but it is not limited to one, and multiple clamp devices 300 may be mass-produced at the same time.

Now, center positions c1 and c2 are positioned symmetrically at an interval between one side and the other side of two parts divided by a line L1 connecting the midpoints of the short side 39c and the short side 39d of the metal member 390 (FIG. 5(a)). Then, circular holes H1H3 and H2H4 are formed in the thickness direction with the center positions c1 and c2 as centers (FIG. 5(b)). These circular holes H1H3 and H2H4 are formed by a hole forming drill. Next, grooves are formed on the inner wall surfaces of the circular holes H1H3 and H2H4 by a groove forming drill. In this case, the tip of the mountain of the groove is formed to be a trapezoid by selecting the diameter of the hole forming drill and the tooth height of the groove forming drill. The length of the upper side of the trapezoid can be selected by selecting the tooth height of the groove forming drill (FIG. 5(c)). Next, cutting is performed with an end mill along the line L1, and the first metal fitting 310 and the second metal fitting 320 are roughly completed (Figure 5 (c)).

The first metal fitting 310 and the second metal fitting 320 configured as described above can simultaneously form deep grooves H1 and H4 and shallow grooves H3 and H2. With this configuration, as explained in FIG. 4, various combinations of grooves H1-H4 can be used depending on the diameter of the cable used. When the two cables used are both thick and the same diameter, one of the two cables has a small diameter and the other has a large diameter (examples in FIG. 4(b) and (c)).

Figure 6 shows a plan view of the processing of the metal member 390 as seen from the front. Figure 6(a) shows the state at the stage of Figure 5(b). Center positions c1 and c2 are positioned symmetrically at a distance between one side and the other side of two parts divided by a line L1 connecting the midpoints of the short sides 39c and 39d of the metal member 390. Figure 6(b) shows the state at the stage of Figure 5(c). In this state, cutting is performed with an end mill 900 with a width (shown by diagonal lines) centered on line L1 of the metal member 390. Figure 6(c) shows the state at the stage of Figure 5(d). In this state, the first metal fitting 310 and the second metal fitting 320 are obtained.

That is, according to an embodiment, the method includes a step of forming at least a first hole and a second hole adjacent to each other in a metal member, and a step of machining a screw groove that spirals in the axial direction in the first hole and the second hole. The method further includes a step of cutting the metal member across a line connecting the centers of the first hole and the second hole and on a thick line that divides the first hole and the second hole, to obtain the first fitting with the first two cable fixing grooves formed therein and the second fitting with the second two cable fixing grooves formed therein.

7( a ) and 7 ( b ) show how the metal member 390 is cut by the end mill 900 .
As described above, the first embodiment has the first fitting 310 and the second fitting 320. Basically, the first fitting 310 has a semi-cylindrical first cable fixing groove formed on one surface, and the second fitting 320 has a semi-cylindrical second cable fixing groove formed on one surface. Here, the first cable fixing groove and the second cable fixing groove comprise a part of a screw structure formed by thread processing. The first fitting 310 and the second fitting 320 are joined together so that the first cable fixing groove and the second cable fixing groove face each other, and the cable is sandwiched between the first cable fixing groove and the second cable fixing groove and pressure-welded and fixed. Here, the semi-cylindrical shape refers to a state in which a cylinder is cut along a plane perpendicular to the bottom surface, and the cross-sectional shape parallel to the bottom surface is semicircular or arched.

In the above embodiment, a method for manufacturing a cable clamp device having a first fitting with two semi-cylindrical first cable fixing grooves formed on one surface and a second fitting with two semi-cylindrical second cable fixing grooves formed on one surface has been described. However, the present invention is not limited to this, and may be a method for manufacturing a cable clamp device having a first fitting with a semi-cylindrical first cable fixing groove formed on one surface and a second fitting with a semi-cylindrical second cable fixing groove formed on one surface, which may include a step of cutting the metal member on a line dividing the hole to obtain the first fitting with the first cable fixing groove formed and the second fitting with the second cable fixing groove formed. The effect is as described in FIG. 3(b). In other words, the clamp device may clamp one cable.

According to at least one of the embodiments described above, the cable clamping portion has a screw groove structure, which increases the cable's resistance to tensile forces.

Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the gist of the invention. These embodiments and their variations are included within the scope and gist of the invention, as well as within the scope of the invention and its equivalents as described in the claims. Furthermore, the scope of the present invention includes cases in which each component of the claims is expressed separately, or multiple components are expressed together, or these are expressed in combination. Multiple embodiments may also be combined, and examples consisting of such combinations are also included in the scope of the invention.

In addition, in order to clarify the explanation, the drawings may show the width, thickness, shape, etc. of each part in a schematic manner compared to the actual embodiment, but this is merely an example and does not limit the interpretation of the present invention. In addition, in this specification and each figure, components that perform the same or similar functions as those described above with respect to the previous figures are given the same reference numerals, and duplicate detailed explanations may be omitted as appropriate. In addition, there is no limitation on the names and terms used, and other expressions that have substantially the same content and meaning are included in the present invention.

100: Explosion-proof device, 200: Cable, 300: Cable clamp device, 310: First fitting, 320: Second fitting, 311: Other surface, 312: One surface, 323: One surface, 324: Other surface, H1-H4: Groove for fixing cable, R1-R4: Part of screw structure, 313: Through hole, 325: Screw hole, 311R: Curved surface, 390: Metal member, 411: Washer, 412: Screw.

Claims (8)

a first fitting having a semi-cylindrical first cable fixing groove formed on one surface;
a second metal fitting having a semi-cylindrical second cable fixing groove formed on one surface,
The first fitting further has a third cable fixing groove spaced apart from the first cable fixing groove,
the second metal fitting further has a fourth cable fastening groove spaced apart from the second cable fastening groove,
The first cable fixing groove and the second cable fixing groove each include a part of a thread groove structure formed by thread processing,
the third cable fixing groove and the fourth cable fixing groove each include a part of a thread groove structure formed by thread processing;
the depth of the first cable fixing groove in the one surface of the first fitting and the third
The depth of the cable fixing groove is different.
the depth of the second cable fixing groove in the one surface of the second metal fitting, and the fourth
The depth of the cable fixing groove is different.
a cable clamp device comprising: a mechanism for assembling the first fitting and the second fitting in either a first state in which the first cable fixing groove and the second cable fixing groove face each other and the third cable fixing groove and the fourth cable fixing groove face each other; or a second state in which the first cable fixing groove and the fourth cable fixing groove face each other and the third cable fixing groove and the second cable fixing groove face each other. The cable clamp device according to claim 1, wherein the semi-cylindrical shape refers to a state in which a cylinder is cut at a plane perpendicular to the bottom surface, and the cross-sectional shape parallel to the bottom surface is semicircular or arched. 3. The method according to claim 1, wherein a part of the thread groove structure has a trapezoidal shape at a protruding tip on an inner diameter side.
13. A cable clamp device according to claim 12. The mechanism for assembling the first metal fitting and the second metal fitting is configured to apply a clamping force to the first metal fitting and the second metal fitting in the assembled state.
The cable clamping device of claim 1 , further comprising a fastener for fastening the metal fitting and the second metal fitting together. 5. The cable clamp device according to claim 4, wherein the fastener comprises: a through hole formed between the first cable fixing groove and the third cable fixing groove of the first fitting; a screw hole formed between the second cable fixing groove and the fourth cable fixing groove of the second fitting and facing the through hole; and a screw passing through the through hole and screwed into the screw hole. A method for manufacturing a cable clamp device having a first fitting having a semi-cylindrical first cable fastening groove formed on one surface thereof, and a second fitting having a semi-cylindrical second cable fastening groove formed on one surface thereof, comprising:
forming a hole in a metal member;
A step of machining a screw groove that spirals in an axial direction in the hole;
and cutting the metal member along a line dividing the hole to obtain the first fitting having the first cable fixing groove formed therein and the second fitting having the second cable fixing groove formed therein. A method for manufacturing a cable clamp device having a first fitting having two semi-cylindrical first cable fastening grooves formed on one surface thereof, and a second fitting having two semi-cylindrical second cable fastening grooves formed on one surface thereof, comprising:
forming adjacent first and second holes in a metal member;
A step of machining a screw groove that spirals in an axial direction in each of the first hole and the second hole;
cutting the metal member across a line connecting the centers of the first hole and the second hole and on a line dividing the first hole and the second hole to obtain the first fitting having the two first cable fixing grooves formed therein and the second fitting having the two second cable fixing grooves formed therein. a first fitting having a semi-cylindrical first cable fixing groove formed on one surface;
a second metal fitting having a semi-cylindrical second cable fixing groove formed on one surface,
The first cable fixing groove and the second cable fixing groove each include a part of a screw groove formed by screw processing, and the semi-cylindrical shape is formed by cutting a cylinder along a plane perpendicular to a bottom surface of the cylinder,
The cross-sectional shape parallel to the bottom surface is an arch shape, and the arch shape of the first cable fixing groove and the second cable fixing groove are
The arcuate shape of the cable fixing groove can be arranged on a part of a circle,
a depth of the first cable fixing groove from the surface and a depth of the second cable fixing groove from the surface are different, and when the first cable fixing groove and the second cable fixing groove are directly opposed to each other, a distance between one edge and the other edge of the first cable fixing groove and a distance between one edge and the other edge of the second cable fixing groove are different,
A cable clamp device capable of fitting the first fitting and the second fitting together so that the first cable fixing groove and the second cable fixing groove face each other, and clamping and pressurizing a cable between the first cable fixing groove and the second cable fixing groove.

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