JP7530219B2 - Cable fixing structure and multi-core cable - Google Patents

Description

The present invention relates primarily to a fixing structure for arranging and fixing multiple cables in parallel, and to a multi-core cable that uses the fixing structure.

Cables used in semiconductor manufacturing equipment, industrial robots, etc., especially in moving parts, are commonly made up of multiple cables arranged in parallel, known as ribbon cables or bare cables.

As one fixing structure for arranging cables in parallel, Patent Documents 1 and 2 disclose a fixing structure that uses a thin-film reinforcing member and integrates the reinforcing member and the cable by fusing them together (see Figures 5(a) and (b)).

In particular, the fixing structure of Patent Document 2 is characterized in that a thin-film reinforcing member is provided to cover at least one surface of a plurality of cables, and the outermost layers of adjacent cables are not fused, but the reinforcing member and the outermost layers are fused to each other.
In addition, since the reinforcing member and the outermost layer are made of compatible materials, they are firmly fixed together by heat fusion.

However, even with such a strong fixing structure, in harsh usage environments where the cable is repeatedly bent in more complex conditions, the load on the cable is significant, and problems such as the reinforcing members peeling off from the cable may occur, particularly at both linear ends of each fixing part.

JP 2015-22890 A JP 2016-95955 A

The objective of the present invention is to provide a cable fixing structure and a multi-core cable that are highly durable even in increasingly complex and severe operating environments and do not peel off at the fixing parts.

The gist of the present invention is as follows:

(1) A cable fixing structure of the present invention is a structure for fixing a plurality of parallel cables in a parallel state at least in a part in a longitudinal direction, in which a first reinforcing member is fused to both sides of the parallel surfaces of the parallel cables at a fixing portion of the plurality of cables,
A second reinforcing member is provided at at least one location between adjacent cables,
The present invention is characterized in that at the location where the second reinforcing member is provided, the outermost layers of adjacent cables are not fused to each other, but the second reinforcing member and the outermost layers are fused to each other, and the second reinforcing member is fused to each of the first reinforcing members fused to both sides of the parallel surfaces .
(2) In the cable fixing structure of the present invention, it is preferable that the melting point of the layer in contact with the outermost layer of the first reinforcing member and/or the second reinforcing member is lower than the melting point of the outermost layer.
(3) In the cable fixing structure of the present invention, it is preferable that the second reinforcing members are provided between all of the adjacent cables.
(4) A multi-core cable having the cable fixing structure characterized above.

The cable fixing structure and multi-core cable of the present invention are highly durable even in increasingly complex operating environments, and peeling does not occur at the fixing parts, allowing for stable long-term use.

1 is a reference embodiment of a cable fixing structure according to the present invention. 1A and 1B show basic aspects of the cable fixing structure of the present invention. 2 is an example of a multi-core cable using the cable fixing structure of the present invention. 1A and 1B are schematic diagrams showing a method for measuring (a) the tensile strength and (b) the peel strength of a cable fixing structure. 1 is a diagram showing an embodiment of a cable fixing structure according to the prior art.

Hereinafter, the basic configuration of the present invention will be described with reference to the drawings, but the present invention is not limited thereto.
The cable fixing structure 1 shown in Fig. 1 is a reference structure of the present invention. A cable 2 is composed of a signal wire 3 and is covered with an outermost layer (sheath) 4. A plurality of cables 2 are integrated and fixed by a first reinforcing member 5 and a second reinforcing member 6. An inter-cable fixing portion X is a fixing portion between the cables 2 by the second reinforcing member 6.

In the reference structure of the cable fixing structure 1 of the present invention, a first reinforcing member 5 is provided so as to cover at least one surface of a plurality of parallel cables 2, a second reinforcing member 6 is provided at least in one location between adjacent cables 2, and the first reinforcing member 5 and the second reinforcing member 6 are at least partially joined ( FIG. 1 ). By providing the second reinforcing member 6 between adjacent cables 2 in addition to the first reinforcing member 5 and joined to the first reinforcing member, peeling (breakage) of the inter-cable fixing portion X is reduced, and the durability (fixing strength) of the cable fixing structure is improved. The method of joining the first reinforcing member and the second reinforcing member is not limited, but joining by heat fusion is preferable in terms of joining strength.

The first reinforcing member 5 is provided so as to cover at least one side of the parallel cables 2 as shown in FIG. 1. It may be provided so as to cover only one side of the parallel cables, both sides, or a combination of these, and is not particularly limited. From the viewpoint of improving the fixing strength between the cables, a structure that covers both sides, and in particular the entire circumference of the cables, as shown in FIG. 2(a) and (b) is preferable.

The second reinforcing member 6 is provided at least at one location between adjacent cables 2 (inter-cable fixing portion X). The number of inter-cable fixing portions X is not limited, but the more there are, the more the durability of the cable fixing structure 1 is improved.

2(a) and (b) show basic aspects of the cable fixing structure 1 of the present invention, which is a more preferable structure in terms of durability of the cable fixing structure. Fig. 2(a) shows a structure in which inter-cable fixing parts X are provided between all of the cables. In terms of durability, it is preferable to provide them between all of the adjacent cables 2, but when considering improvement in flexibility and productivity, they may be provided in every two places as shown in Fig. 2(b), for example.

In the cable fixing structure 1 of the present invention, it is preferable that the outermost layers 4 of adjacent cables 2 are not fused to each other, but the first reinforcing member 5 and the outermost layer 4, and the second reinforcing member 6 and the outermost layer 4 are fused to each other. Since the cables 2 are not directly fixed to each other by fusion or the like, the thermal load on the cables 2 is reduced.

In order to strengthen the fixing strength between the outermost layer 4 and the reinforcing members 5, 6 of the cable, it is preferable that the outermost layer 4 and the reinforcing members 5, 6 are made of compatible materials. "Compatible" means that they are made of the same material or have similar chemical structures and therefore tend to mix with each other when melted. When the outermost layer and the reinforcing members are compatible, they mix with each other when fused, resulting in a stronger fusion (bond).

In addition, it is preferable that the first reinforcing member 5 and/or the second reinforcing member 6 have a multi-layer structure. This is because the material of the reinforcing member that is compatible with the outermost layer does not necessarily have excellent other properties such as flexibility. For example, if flexibility is required, the reinforcing member has a two-layer structure, and the layer in contact with the outermost layer (hereinafter referred to as the fusion layer) is made of a material that is highly compatible with the outermost layer, and the other layer is made of the same type of material as the fusion layer but with a more flexible composition, thereby achieving both strong fusion and flexibility. The layers other than the fusion layer may be appropriately selected from materials having the necessary properties, without being limited to flexibility. More preferably, all of the first reinforcing member 5 and the second reinforcing member 6 have a multi-layer structure.

Furthermore, it is preferable that the melting point of the layer of the first reinforcing member 5 and/or the second reinforcing member 6 that is in contact with the outermost layer 4 is lower than the melting point of the outermost layer 4. When heating the reinforcing member to fuse to the outermost layer, the thermal load on the outermost layer 4 can be reduced.

When the first reinforcing member 5 and/or the second reinforcing member 6 have a multi-layer structure, it is preferable to set the melting point of the melting layer (the layer that is bonded to the outermost layer 4 of the cable 2) lower than the melting point of the outermost layer 4 of the cable 2. With this configuration, when heat-sealing, the melting layer of the reinforcing member melts before the outermost layer 4 starts to melt, so that fusion (bonding) can be completed before the cable 2 is affected by heat. It is preferable to set the melting point of the layers other than the melting layer higher than the melting point of the melting layer, since this can minimize changes in appearance after fusion. It is to be noted that the melting point in this invention does not only refer to the temperature at which the material melts and becomes liquid, but also refers to the temperature at which the material softens to the extent that it can be fused, for convenience.

The first reinforcing member 5 and/or the second reinforcing member 6 are preferably thin-film shaped from the viewpoint of reducing the thermal effect on the cable 2 and ease of handling. Thin-film shaped refers to a shape in which the thickness is sufficiently small compared to the length, width, and outer diameter of the cable 2, and examples of such shapes include sheet-shaped and tape-shaped reinforcing members. By making the reinforcing member thin-film shaped, the contact surface between the outermost layer 4 and the reinforcing member can be heated quickly, and fusion is completed in a short time, minimizing the thermal effect on the cable 2. In addition, the thickness changes little even when the reinforcing member is provided, so it can be minimized.

When using the first reinforcing member 5 and/or the second reinforcing member 6, which are thin films, it is preferable that the thickness is in the range of 100 to 2000 μm from the viewpoint of fixing strength and fusion workability. By making the thin film reinforcing member of an appropriate thickness, the contact surface between the outermost layer 4 and the reinforcing member can be heated quickly, and the fixing strength after fusion can be ensured.

The material of the first reinforcing member 5 and/or the second reinforcing member 6 is not particularly limited, but examples include thermoplastic/curable elastomers in terms of flexibility. In terms of mechanical strength and versatility, polyurethane is preferred.

The first reinforcing member 5 and/or the second reinforcing member 6 may all be the same in terms of shape, dimensions, material, etc., but are not particularly limited thereto. From the viewpoint of productivity, it is preferable that the first reinforcing member 5 and the second reinforcing member 6 are made of the same material and are integrated.

If necessary, a self-supporting member (not shown) may be provided inside the first reinforcing member 5 so as to come into contact with the outermost layer 4 of the cable 2. In principle, this self-supporting member is made of a material that is more rigid than the cable 2 or the reinforcing members 5 and 6. By providing a self-supporting member with high rigidity, the cable 2 becomes less likely to bend, and inadvertent deformation of the cable 2 when it is used in the air can be suppressed.

There is no particular limit to the location where the cable fixing structure 1 is applied, but it is preferable to provide the cable fixing structure 11 only in a portion of the desired location, rather than over the entire length of the cable, as in the case of the multi-core cable 7 in Figure 3. Only necessary locations in the cable length are fused and fixed in parallel to the outermost layer 4 of the cable with the reinforcing member, which increases the freedom of cable wiring and improves flexibility. There is no limit to the number or length of the cable fixing structures 1, 11 in the cable length direction.

As described above, since only the desired position in the length direction of the cable can be fixed, the fixing structure 11 can be formed after the cable has been deformed into the desired shape. For example, as shown in the multi-core cable 7 in FIG. 3, when multiple parallel cables are bent along a horizontal plane, the cables are bent and then the fixing structure 11 is provided near the bend. As a result, a cable fixing structure 11 with excellent durability can be obtained, even in increasingly complex and harsh operating environments.

Furthermore, as shown in the multi-core cable 7 in Figure 3, the cable fixing structure 11 of the present invention is also suitable for use when a cable is branched near the fixing structure. The cable fixing structure 11 of the present invention has high tensile strength, so even if the branched cable 2 is pulled and a force that would tear the fixing part is applied, it has high durability compared to conventional cable fixing structures and is useful in increasingly complex and harsh usage environments.

The method of fusing the cable 2 to the first reinforcing member 5 and the second reinforcing member 6 is not particularly limited, but a method using a fusion mold is preferred. A number of cables and reinforcing members are placed in a fusion mold, and the mold is heated to obtain the cable fixing structure 1. By using a fusion mold of a specified length, the cable 2 can be fixed at a specified length only at desired positions in the length direction.

For reference, cable 2 is shown below, but is not limited to this.

The number of cables 2 is not particularly limited, and the cable 2 is made up of multiple cables.

The structure of the signal wire 3 constituting the cable 2 is not particularly limited, and examples include an electric wire in which a conductor wire is covered with an outermost layer 4, a coaxial cable composed of an inner conductor, a dielectric, a shielding layer, and an outermost layer 4, an optical fiber cable in which an optical fiber is covered with an outermost layer 4, and a multi-core cable in which these are combined and appropriately covered together with a shielding layer or an outermost layer 4. The sizes of the multiple cables 2 may be the same or different, and are not particularly limited.

The multiple cables 2 arranged in parallel may be provided with resin tubes, rods, fibers, etc., in addition to the cables 2. For example, the tubes may be single-layer or multi-layer tubes for transporting air or liquid. In this case, it is preferable that the outermost layer of the tube is a layer equivalent to the outermost layer 4 of the cable 2 in order to be bonded to the reinforcing member.

The material of the outermost layer 4 that constitutes the cable is not particularly limited, but it is preferable that it is compatible with the reinforcing member. When the reinforcing member is polyurethane, PVC, polyurethane, etc. are preferable. In addition, it may be either a single layer or a multi-layer, and a separate sheath may be provided inside the outermost layer 4. For example, a highly flexible sheath is applied for reinforcement purposes, and then the outermost layer 4 is applied to obtain a cable fixing structure.

When multiple cables 2 are arranged in parallel, their vertical positions (heights) may be aligned at the base or at the center of the cables, and are not particularly limited.

Example 1 is an example of the cable fixing structure 1 of the present invention, and is a structure in which inter-cable fixing parts X are provided between all cables, as shown in Figure 2 (a).

An outermost layer 4 made of polyurethane with a melting point in the range of 160-170°C is applied onto multiple signal wires 3, and eight cables 2 with an outer diameter of 8.0 mm are prepared.

After arranging the eight cables 2 in parallel, they are fixed over 90 mm of their length with a first reinforcing member 5 and a second reinforcing member 6 to form a cable fixing structure 1. The cables 2 and reinforcing members are placed in a fusion mold and then heated to fix them. The reinforcing members are all thin polyurethane sheets with a thickness of 500 μm and a two-layer structure. Of these polyurethane sheets, the layer in contact with the outermost layer 4 (melting layer) is a polyurethane layer with high flexibility compared to the other layers, and has a lower melting point than the outermost layer 4.

The comparative example is a conventional cable fixing structure 51 consisting of only a reinforcing member 55, as shown in FIG. 5(b) among the examples.

In order to confirm the durability (fixing strength) of the cable fixing structure for the examples and comparative examples, the tensile strength is measured. The measurement method is shown below.

(Measurement method)
The evaluation sample used was a cable fixing structure cut to a length of 60 mm. As shown in Figure 4(a), both ends of the cable were fixed in the chucks of a tensile tester, and the cable was pulled at a pulling speed of 50 mm/min, and the maximum force [N] until the reinforcing member broke (peeled off) was measured.

As shown in the measurement results (Table 1), the tensile strength of the embodiment is significantly improved compared to the comparative example.

In addition, a peel test of the reinforcing member is performed for the examples and comparative examples. The measurement method is as follows.

(Measurement method)
The evaluation sample was a multi-core cable with a length of 200 mm, of which the portion of the cable fixing structure was 90 mm, and the fixing strength between the reinforcing member used for fixing and the cable was measured. That is, as shown in Fig. 4(b), the reinforcing member and the cable were each fixed to the chuck of a tensile tester, and pulled at a pulling speed of 50 mm/min, and the maximum force [N] at which the reinforcing member peeled off from the cable was measured.

As shown in the measurement results (Table 2), the peel strength of the examples is significantly improved compared to the comparative examples.

In conclusion, the cable fixing structure 1 in the embodiment is far superior to the cable fixing structure 51 of the conventional technology in the comparative example as a result of the tensile test and the peel test, and is useful even in increasingly complex and severe usage environments.

The above example is merely one example of the present invention, and it goes without saying that various modifications and applications are possible within the scope of the concept of the present invention. Although the fixing structure of the present invention is designed to fix cables in parallel, it can be applied to fixing cables in various arrangements other than parallel arrangements, and to various long items other than cables, such as providing a fusion layer around the outside of a metal pipe and fixing only the necessary parts.

1, 11, 51 Cable fixing structure (fixing part)
2, 52 Cable 3, 53 Signal line 4, 54 Outermost layer (sheath)
5 First reinforcing member 55 Reinforcing member (prior art)
6 Second reinforcing member 7 Multi-core cable X Inter-cable fixing portion

Claims (6)

A structure for fixing a plurality of parallel cables in a parallel state at least in a part of the length direction,
In the fixing portion of the plurality of cables, a first reinforcing member is fused to both sides of the parallel surfaces of the plurality of cables arranged in parallel,
A second reinforcing member is provided at least at one location between adjacent cables,
A cable fixing structure characterized in that, at the location where the second reinforcing member is provided, the outermost layers of adjacent cables are not fused to each other, but the second reinforcing member and the outermost layers are fused to each other, and the second reinforcing member is fused to each of the first reinforcing members fused to both sides of the parallel surfaces . In the first reinforcing member and/or the second reinforcing member, a melting point of a layer in contact with the outermost layer is lower than a melting point of the outermost layer.
The cable fixing structure according to claim 1 . The second reinforcing member is provided between all of the adjacent cables.
The cable fixing structure according to any one of claims 1 to 2. A multi-core cable having the cable fixing structure according to any one of claims 1 to 3. A plurality of parallel cables are fixed in a bent state.
5. The multi-core cable according to claim 4. A structure for fixing a plurality of parallel cables in a parallel state at least in a part of the length direction,
At least one of the plurality of cables includes a plurality of signal lines and is collectively covered,
In the fixing portion of the plurality of cables, a first reinforcing member is fused to both sides of the parallel surfaces of the plurality of cables arranged in parallel,
A second reinforcing member is provided at at least one location between adjacent cables,
A cable fixing structure characterized in that, at the location where the second reinforcing member is provided, the outermost layers of adjacent cables are not fused to each other, but the second reinforcing member and the outermost layers are fused to each other, and the second reinforcing member is fused to each of the first reinforcing members fused to both sides of the parallel surfaces.

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