Silo temperature measuring cable

Abstract

To provide a silo temperature measuring cable in which even when resin case is fractured, the falling of the fractured resin case can be suppressed and the occurrence of such a problem that the silo temperature measuring cable cannot measure silo temperature can be suppressed.SOLUTION: A silo temperature measuring cable comprises: a wire rope; a plurality of conductors extending from the top to the bottom of the wire rope, and wound around an outer periphery of the wire rope; a sensing unit incorporated into at least one of the plurality of conductors; a resin sheath provided on the outside of the plurality of conductors, and covering the plurality of conductors and the sensing unit; and a sheath fall prevention stopper provided on the wire rope below the resin sheath.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a silo temperature measurement cable.

Background Art

[0002] Conventionally, it has been required to measure and monitor the temperature inside a silo and maintain it at a predetermined temperature state. As a means for measuring the temperature inside the silo, for example, a silo temperature measurement cable for measuring the temperature inside the silo is used. The silo temperature measurement cable is attached to a hanging part provided at the upper part of the silo and supported inside the silo, so that the temperature inside the silo can be measured.

[0003] For example, Patent Document 1 describes a temperature signal transmission wire cable having a plurality of temperature signal transmission wires at the center and a surrounding reinforcing part including a wire rope that is slidable in the longitudinal direction with respect to the plurality of wires. The reinforcing part is a resin sheath and is composed of a polyethylene resin or the like.

[0004] However, in the wire cable of Patent Document 1, when the resin sheath breaks, the broken and fallen resin sheath mixes into the stored material stored in the silo. Therefore, it is necessary to remove the fallen resin sheath from the stored material. Furthermore, due to the fall of the resin sheath, the temperature signal transmission wire is exposed, and there is a risk that temperature measurement may become impossible due to rubbing between the exposed temperature signal transmission wire and the stored material.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] An object of the present disclosure is to provide a silo temperature measurement cable that can suppress the fall of a broken resin sheath and suppress the inability to measure temperature even when the resin sheath breaks.

Means for Solving the Problems

[0007] [1] A silo temperature measurement cable comprising a wire rope, a plurality of conductors extending from above to below the wire rope and wound along the outer circumference of the wire rope, a sensing part incorporated in at least one of the plurality of conductors, a resin sheath provided outside the plurality of conductors and covering the plurality of conductors and the sensing part, and a sheath fall prevention stopper provided at a portion of the wire rope below the resin sheath. [2] The silo temperature measurement cable according to [1] above, wherein the sheath fall prevention stopper is provided at a portion of the wire rope that combines a portion extending from above to below and a lower end portion extending from below to above. [3] The silo temperature measurement cable according to [1] above, wherein the sheath fall prevention stopper is provided at the lower end portion of the wire rope. [4] The silo temperature measurement cable according to any one of [1] to [3] above, wherein the resin sheath is made of a polypropylene resin. [5] The silo temperature measurement cable according to any one of [1] to [4] above, wherein the tensile strength of the resin sheath is 25.0 MPa or more. [6] The silo temperature measurement cable according to any one of [1] to [5] above, wherein the resin sheath is made of a block polypropylene resin. [7] The silo temperature measurement cable according to any one of [1] to [6] above, wherein the elongation force of the resin sheath is 700% or more.

Advantages of the Invention

[0008] According to the present disclosure, it is possible to provide a silo temperature measurement cable that can suppress the fall of a broken resin sheath and suppress the inability to measure temperature even when the resin sheath is broken.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Modes for Carrying Out the Invention

[0010] Hereinafter, a detailed description will be given based on embodiments.

[0011] The inventors analyzed the reason why the resin sheath constituting the silo temperature measurement cable suspended in the silo breaks and falls inside the silo. As an example of the analysis result, it was found that the resin sheath of the silo temperature measurement cable suspended in the silo expands when the grain introduced from the upper part of the grain silo hits the resin sheath of the silo temperature measurement cable, and finally the resin sheath breaks and falls into the stored material in the silo. The resin sheath that has broken and fallen in this way is mixed as a foreign substance into the stored material in the silo, so it is necessary to remove the resin sheath, which is a foreign substance, from the stored material, resulting in extra costs. In addition, when the broken resin sheath falls, the core wire covered by the resin sheath is exposed. There is a risk that the wire may break when the grain hits the exposed core wire, or the conductor may be exposed, making it impossible to measure the temperature with the silo temperature measurement cable.

[0012] As a result of intensive research, the inventors of the present invention have found that by providing a stopper for preventing the sheath from falling below the resin sheath, the silo temperature measurement cable can suppress the fall of the broken resin sheath and prevent the temperature measurement from becoming impossible even if the resin sheath is broken. Based on this finding, the present disclosure has been completed.

[0013] The silo temperature measurement cable of the embodiment includes a wire rope, a plurality of conductive wires extending from above to below the wire rope and wound along the outer periphery of the wire rope, a sensing part incorporated in at least one of the plurality of conductive wires, a resin sheath provided outside the plurality of conductive wires and covering the plurality of conductive wires and the sensing part, and a stopper for preventing the sheath from falling provided at a portion of the wire rope below the resin sheath.

[0014] (First Embodiment) FIG. 1 is a front view showing an example of the silo temperature measurement cable of the first embodiment. In FIG. 1 and FIG. 3 described later, the resin sheath 5, the stopper 6 for preventing the sheath from falling, and the mold part 7 are shown transparently so that the configurations of the wire rope 2, the conductive wire 3, and the sensing part 4 can be easily understood.

[0015] As shown in FIG. 1, the silo temperature measurement cable 1 of the embodiment includes a wire rope 2, a plurality of conductive wires 3, a sensing part 4, a resin sheath 5, and a stopper (hereinafter also simply referred to as a stopper) 6 for preventing the sheath from falling. The silo temperature measurement cable 1 is a cable for measuring the temperature inside the silo.

[0016] As shown in FIG. 2 described later, the wire rope 2 constituting the silo temperature measurement cable 1 is installed in a suspended state inside the silo 80 and supports a plurality of conductive wires 3 wound around the outer periphery of the wire rope 2 from the center. The wire rope 2 is a stranded wire formed by twisting a plurality of metal wire rods. Further, the outer periphery of the wire rope 2 may be covered with a holding tape (not shown).

[0017] As shown in Fig. 1, an upper end loop portion 21 is provided at the upper end of the silo temperature measurement cable 1, where a wire rope 2 is folded back in a loop shape. Further, a protective fitting 22 such as a thimble is attached inside the upper end loop portion 21. The portion of the wire rope 2 that combines the part extending from below upward and the upper end portion extending from above downward is bundled by a metal sleeve 23.

[0018] A plurality of conducting wires 3 extend from above the wire rope 2 downward and are wound along the outer periphery of the wire rope 2. The plurality of conducting wires 3 provided across the axial direction of the wire rope 2 are wound around the wire rope 2 in a spiral shape while contacting each other, as shown in Fig. 1 for example.

[0019] Here, an example is shown where the silo temperature measurement cable 1 includes 12 conducting wires 3. However, the number of conducting wires 3 is not particularly limited as long as it is a plurality, and is appropriately set according to the use of the silo temperature measurement cable 1 and the like.

[0020] The conducting wire 3 is, for example, a stranded wire formed by twisting wire materials made of copper. Further, the outer periphery of the conducting wire 3 is covered with an insulator (not shown).

[0021] The sensing part 4 is a member that senses temperature and is incorporated into at least one of the plurality of conducting wires 3. One sensing part 4 is incorporated into one conducting wire 3. For example, as shown in Fig. 1, each of the plurality of sensing parts 4 is incorporated into a different one of the plurality of conducting wires 3.

[0022] The sensing part 4 is not particularly limited as long as it is a member that senses temperature, and is composed of, for example, a resistance temperature detector or a thermocouple.

[0023] When the silo temperature measurement cable 1 includes a plurality of sensing parts 4, each of the plurality of sensing parts 4 is provided at a different position along the axial direction of the wire rope 2 and senses the temperature at a predetermined height inside the silo. In FIG. 1, each of the five sensing parts 4 is incorporated into each of the five conductive wires 3, and each sensing part 4 can sense the temperature at five heights inside the silo.

[0024] Here, an example in which the silo temperature measurement cable 1 includes five sensing parts 4 is shown. However, the number of sensing parts 4 is not particularly limited as long as it is one or more, and is appropriately set according to the use of the silo temperature measurement cable 1 and the like.

[0025] The resin sheath 5 is provided outside the plurality of conductive wires 3 at a portion where the plurality of conductive wires 3 are wound around the outer periphery of the wire rope 2, and covers the plurality of conductive wires 3 and the sensing part 4 from the outside. Inside the cylindrical resin sheath 5, a plurality of conductive wires 3 wound along the outer periphery of the wire rope 2 and one or more sensing parts 4 incorporated in the plurality of conductive wires 3 are arranged.

[0026] The resin sheath 5 extending in the longitudinal direction of the silo temperature measurement cable 1 extends, for example, to the lower ends of the plurality of conductive wires 3 extending from above the wire rope 2 to below. The resin sheath 5 is made of, for example, polypropylene resin or polyethylene resin.

[0027] As the resin sheath 5, it is preferable to satisfy at least one of the requirements that the resin sheath 5 is made of polypropylene resin and that the tensile strength of the resin sheath 5 is 25.0 MPa or more. When the resin sheath 5 satisfies any one of these requirements, the mechanical strength of the resin sheath 5 is improved. Therefore, even if it is the same as the thickness of a resin sheath such as polyethylene resin, that is, even if the thickness of the resin sheath 5 is not increased, partial breakage or fracture of the resin sheath 5 caused by the grain or the like input from the upper part of the silo hitting the resin sheath 5 of the silo temperature measurement cable 1 can be suppressed.

[0028] Thus, even without increasing the thickness, breakage of the resin sheath 5 can be suppressed, so that the silo temperature measurement cable 1 can be substantially lightened. Furthermore, breakage of the resin sheath 5 can be suppressed by controlling the material and mechanical properties of the resin sheath 5 without complicating the structure of the silo temperature measurement cable 1. As a result, the silo temperature measurement cable 1 can have a long service life, and the replacement frequency of the silo temperature measurement cable 1 for the silo, which involves manual work at a height of about several tens of meters, can be reduced.

[0029] From such a viewpoint, as the resin sheath 5, it is preferable to satisfy both requirements that the resin sheath 5 is composed of a polypropylene resin and the tensile strength of the resin sheath 5 is 25.0 MPa or more. Among them, it is more preferable that the resin sheath 5 is composed of a block polypropylene resin. Also, the tensile strength of the resin sheath 5 is more preferably 35.0 MPa or more, and even more preferably 40.0 MPa or more.

[0030] The tensile strength of the resin sheath 5 is measured using a dumbbell-shaped test piece in accordance with 4.16.4.1 Tensile strength of JIS C 3005:2014.

[0031] Also, from the viewpoint of suppressing breakage of the resin sheath 5 as described above, the elongation force of the resin sheath 5 is preferably 700% or more, and more preferably 750% or more.

[0032] The elongation force of the resin sheath 5 is measured using a dumbbell-shaped test piece in accordance with 4.16.4.2 Elongation of JIS C 3005:2014.

[0033] Also, the resin sheath 5 may contain additives such as an antioxidant.

[0034] The stopper 6 is provided at a portion of the wire rope 2 below the resin sheath 5. Further, at the lower end of the silo temperature measuring cable 1 below the stopper 6, a lower end loop portion 24 is provided where the wire rope 2 is folded back in a loop shape. The stopper 6 is provided at a portion of the wire rope 2 that combines the portion extending from above downward and the lower end portion extending from below upward.

[0035] The stopper 6 may be clamped to the wire rope 2, for example, by compression or crimping, or may be joined to the wire rope 2 by welding such as laser welding. The stopper 6 is provided on the wire rope 2 but not on the conductive wire 3 and the resin sheath 5.

[0036] The stopper 6 is preferably composed of a copper-based material including copper and copper alloys, an aluminum-based material including aluminum and aluminum alloys, or stainless steel. From the viewpoint of oxidation resistance, an aluminum-based material or stainless steel is preferable.

[0037] Since the stopper 6 is provided at a portion of the wire rope below the resin sheath 5, the fall of the resin sheath 5 can be suppressed. Furthermore, even if the resin sheath 5 breaks, the broken resin sheath 5 is supported from below by the stopper 6 provided on the wire rope 2, so that the fall of the broken resin sheath 5 can be suppressed. Also, even if the resin sheath 5 breaks, the state in which the conductive wire portion incorporating the sensing portion 4 is covered with the resin sheath 5 can be maintained over a long period, so that the inability to measure the temperature of the silo temperature measuring cable 1 can be suppressed over a long period.

[0038] Also, from the viewpoint of further suppressing the fall of the broken resin sheath 5, the outer shape of the stopper 6 is preferably larger than the outer shape of the resin sheath 5.

[0039] Further, it is preferable that a mold portion 7 is provided above the stopper 6 and at a portion where the lower end portion of the resin sheath 5 and the wire rope 2 are combined. Below the plurality of conductive wires 3, they are covered with the resin sheath 5 and further sealed from the outside by the mold portion 7. The mold portion 7 is made of resin.

[0040] If the silo temperature measurement cable 1 does not have the mold portion 7, static electricity may be generated when the conductive wire portion exposed downward from the lower end portion of the resin sheath 5 hits grains or the like introduced from the upper part of the silo, and grains powder or the like may adhere to the silo temperature measurement cable 1, which may make it impossible to measure the temperature of the silo temperature measurement cable 1. However, since the silo temperature measurement cable 1 having the mold portion 7 can suppress the generation of the static electricity, it is possible to further suppress the impossibility of temperature measurement of the silo temperature measurement cable 1.

[0041] FIG. 2 is a schematic view showing an example of a state in which the silo temperature measurement cable of the first embodiment is suspended in the silo.

[0042] As shown in FIG. 2, the silo temperature measurement cable 1 can be attached to the silo 80 by hooking the upper end loop portion 21 of the silo temperature measurement cable 1 on the hanging portion 81 provided at the upper part of the silo 80. Thus, the silo temperature measurement cable 1 can maintain a state of being suspended from the upper part to the lower part in the silo 80. The plurality of sensing portions 4 provided on the silo temperature measurement cable 1 are arranged at different height positions in the silo 80.

[0043] The stored material S stored in the silo 80 is introduced into the inside of the silo 80 through the inlet 82 provided at the upper part of the silo 80. Further, the stored material S stored in the silo 80 is discharged to the outside of the silo 80 through the discharge port 83 provided at the lower part of the silo 80.

[0044] The silo temperature measurement cable 1 installed in a state of being suspended from the upper part of the silo 80 senses the temperatures at different height positions inside the silo 80 with each sensing part 4, and by sending the signals obtained by the sensing part 4 to the measuring instrument 84, the temperatures at different height positions inside the silo 80 are measured.

[0045] Such a silo temperature measurement cable 1 can be used for various silos 80 such as agricultural silos like grain silos and coal silos.

[0046] According to the first embodiment described above, by providing a stopper below the resin sheath, the silo temperature measurement cable can suppress the fall of the broken resin sheath and suppress the occurrence of the inability to measure temperature even if the resin sheath breaks.

[0047] (Second Embodiment) FIG. 3 is a front view showing an example of the silo temperature measurement cable of the second embodiment.

[0048] In the embodiments shown below, the same reference numerals are given to the same components as those of the silo temperature measurement cable 1 of the first embodiment, and redundant descriptions are omitted or simplified.

[0049] In the second embodiment, the configuration of the silo temperature measurement cable 1a is basically the same as that of the silo temperature measurement cable 1 of the first embodiment, except that the configuration below the silo temperature measurement cable 1a is different. Therefore, here, the different configuration will be mainly described.

[0050] As shown in FIG. 3, in the silo temperature measurement cable 1a of the second embodiment, the stopper 6 is provided at the lower end of the wire rope 2 which is the lower end of the silo temperature measurement cable 1a. In the silo temperature measurement cable 1, the lower end of the wire rope 2 is directed from below upward, but in the silo temperature measurement cable 1a, the lower end of the wire rope 2 is directed from above downward.

[0051] Unlike the silo temperature measurement cable 1, the lower end of the silo temperature measurement cable 1a is not provided with the lower end loop portion 24 of the wire rope, but is provided with a linear stopper 6. Therefore, compared with the silo temperature measurement cable 1, the torsion of the silo temperature measurement cable 1a caused by the impact of grains or the like input from the upper part of the silo on the lower end of the silo temperature measurement cable 1a can be suppressed, so that the inability to measure the temperature over a long period of time can be further suppressed.

[0052] According to the second embodiment described above, by providing a stopper at the lower end of the wire rope, which is the lower end of the silo temperature measurement cable, the torsion of the silo temperature measurement cable can be suppressed, so that the inability to measure the temperature can be further suppressed.

[0053] Although the embodiments have been described above, the present invention is not limited to the above embodiments, and includes all aspects included in the concept of the present disclosure and the scope of the claims, and can be variously modified within the scope of the present disclosure.

Description of Reference Numerals

[0054] 1, 1a Silo temperature measurement cable 2 Wire rope 21 Upper end loop portion 22 Protection fitting 23 Metal sleeve 24 Lower end loop portion 3 Conductive wire 4 Sensing portion 5 Resin sheath 6 Sheath drop prevention stopper 7 Molded portion 80 Silo 81 Suspension part 82 Inlet 83 Outlet 84 Measuring instrument S Stored material

Claims

1. A wire rope, a plurality of conducting wires extending from above to below the wire rope and wound along the outer circumference of the wire rope, a sensing part incorporated in at least one of the plurality of conducting wires, a resin sheath provided outside the plurality of conducting wires and covering the plurality of conducting wires and the sensing part, and a stopper for preventing the sheath from falling provided at a portion of the wire rope below the resin sheath. A silo temperature measuring cable comprising the same.

2. The cable according to claim 1, wherein the stopper for preventing the sheath from falling is provided at a portion of the wire rope that combines a portion extending from above to below and a lower end portion extending from below to above.

3. The cable according to claim 1, wherein the stopper for preventing the sheath from falling is provided at the lower end portion of the wire rope.

4. The cable according to any one of claims 1 to 3, wherein the resin sheath is made of polypropylene resin.

5. The cable according to any one of claims 1 to 3, wherein the tensile strength of the resin sheath is 25.0 MPa or more.

6. The cable according to any one of claims 1 to 3, wherein the resin sheath is made of block polypropylene resin.

7. The cable according to any one of claims 1 to 3, wherein the elongation force of the resin sheath is 700% or more.

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