Cable cutter and cutting cable determination device

Abstract

To provide a cable cutter or the like capable of cutting a cable without an error while having excellent workability.SOLUTION: A cable cutter includes a TDR measurement unit 13, a cutting availability determination unit 23, a cutting availability transmission unit 21, and the like. Also, the TDR measurement unit 13 is constructed by a signal input unit 17, a signal reception unit 19, a distance calculation unit 15, and the like. The TDR is means of applying a high-speed pulse or a step signal to a wiring or the like, and observing a reflection waveform reacted. A distance from the measurement unit to a reflection part can be calculated using the time for which this reflection waveform is replied. The TDR measurement unit 13 calculates the distance from the measurement unit to the reflection part from an input pulse signal to a reception pulse signal, and the cutting availability determination unit 23 displays a cutting availability in a display part if the distance information obtained is a predetermined distance or less (e.g., 10 m or less).SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a cable cutter or the like that is used, for example, when cutting and removing an unnecessary cable. [Background technology]

[0002] For example, when removing or replacing existing equipment, there are cases where the cables that are no longer needed are cut and removed along with the equipment. However, when the length of the cables laid is long, for example in a factory, it is difficult to pull out the cables housed in a cable rack from one end. For this reason, the cables are cut, for example, every 10 meters, and one worker pulls the cut cable, and at the next cutting point, another worker identifies the cable that has moved in the cable rack and cuts that cable, and this process is repeated to remove the cables.

[0003] In this case, it is necessary to cut and remove only the intended cable without accidentally cutting other necessary cables. However, many cables are usually stored in a cable rack, and it is difficult to identify only the desired cable among them.

[0004] In response to this, a cable length measuring and cutting machine has been proposed that can measure the length of a cable by inserting the cable into a cable hole and using rollers (Patent Document 1). The cable length measuring and cutting machine of Patent Document 1 is not used for removing an existing cable as described above, but is for pulling out a cable of a desired length from a cable drum and cutting it, but can cut the cable while moving along the cable with the desired cable inserted into the cable hole. This prevents the wrong cable from being cut along the way.

[0005] However, in the method of Patent Document 1, it is necessary to move the cable cutter along the entire length of the cable. As described above, since the cables are bundled in the cable rack, it is difficult to move the cutter along only one of the cables, and the workability is also extremely poor because the cutter must be moved along the entire length of the cable (cable rack).

[0006] In response to this, a cable cutting tool has been proposed that uses a clamp sensor to detect the energized state of the cable clamped by the clamp arm, and restricts cutting when the cable is energized (Patent Document 2). In Patent Document 2, the target cable cannot be cut if it is energized. This makes it possible to prevent other cables in use from being cut by mistake, thinking that they are the cable to be removed.

[0007] However, cables other than the cable to be removed are not necessarily always in a live state. For example, when working in a factory, it is assumed that the power to surrounding equipment is turned off to prevent electric shock accidents. In such a case, it is not possible to distinguish whether the cable is the cable to be removed or not, and whether the power is simply turned off.

[0008] Also, a method has been proposed for identifying a desired cable by introducing a signal into the cable from one end and detecting this signal with a clamp-type induction coil (Patent Document 3). In Patent Document 3, a transmitter is connected to one end of the cable, a predetermined signal is introduced from the transmitter into the cable, and this signal is detected by a clamp (coil) in the middle of the cable, and a signal permitting cutting is transmitted to make the cable ready to be cut if the other end is earthed. With this method, permission to cut is transmitted only when the detected signal matches the signal transmitted from the transmitter, so there is no risk of the cable being mistaken. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] JP 2019-140872 A [Patent Document 2] JP 2014-39346 A [Patent Document 3] Japanese Patent Application Publication No. 11-331049 Summary of the Invention [Problem to be solved by the invention]

[0010] However, the method of Patent Document 3 requires connecting a transmitter to one end, so that it is necessary to reconnect the transmitter to the cut end every time the cable is cut, for example, every 10 m. In addition, it is necessary to connect the cable and the transmitter in a narrow cable rack, which is inefficient to work with.

[0011] The present invention has been made in consideration of the above-mentioned problems, and has an object to provide a cable cutter or the like that is easy to use and can cut cables without accidentally cutting them. [Means for solving the problem]

[0012] In order to achieve the above-mentioned object, a first invention is a cable cutter for cutting a cable to be removed, the cable cutter having a clamping unit capable of clamping the cable midway, a signal input unit in the clamping unit capable of inputting a signal from midway through the cable, and a signal receiving unit capable of receiving a reflected signal reflected by a signal reflecting unit at the end of the cable, the cable cutter being equipped with a TDR measurement unit capable of measuring the distance between the signal input unit and the signal reflecting unit from the time from signal transmission to reception of the reflected signal, a cutter capable of cutting the cable clamped by the clamping unit, a determination unit for determining whether the cable connected to the TDR measurement unit can be cut, and a cutability transmission unit connected to the determination unit for transmitting whether the cable can be cut to a user, the determination unit determining that the cable can be cut when distance information measured by the TDR measurement unit is equal to or less than a predetermined distance, and outputting a message that the cable can be cut to the user via the cutability transmission unit.

[0013] The determination unit may obtain distance information to the signal reflector in each of the directions of the ends of the cable, and determine that the cable can be cut when the shorter distance information is equal to or shorter than a predetermined distance.

[0014] The determination unit may obtain distance information to the signal reflector in each of the directions of the ends of the cable, and determine that the cable cannot be cut if the longer distance information is equal to or shorter than a predetermined distance.

[0015] The determination unit may obtain distance information to the signal reflector in each of the directions of the ends of the cable, and determine that the cable cannot be cut if the longer distance information is equal to or greater than a predetermined distance.

[0016] The clamp unit may have an energization detection unit capable of detecting whether the cable is energized, and when the energization detection unit determines that the cable is energized, the determination unit may determine that the cable cannot be cut.

[0017] The cutoff possibility signaling unit may be a lamp, and may display different colors depending on whether the cutoff is possible or not.

[0018] According to the first invention, a TDR (Time Domain Reflectometer) is used, which can measure the length to the end by inputting a signal into the cable from the middle and detecting the reflected signal at the end, so that when cutting at intervals of about 10 m, for example, it is possible to identify the cable to be removed by searching for a cable that is 10 m away from the end. In this case, since there is no need to input a signal from the end face of the cable, a separate transmitter is not required, and there is no need to move the transmitter each time the cable is cut.

[0019] In addition, distance information to the signal reflecting section at each end of the cable is obtained, and if the shorter distance information is less than a specified distance, it is determined that the cable can be cut, so that the cable to be removed can be identified based on the distance to the end that was previously cut.

[0020] In addition, by obtaining distance information to the signal reflecting section at each end of the cable, and determining that the cable cannot be cut if the longer distance information is less than a predetermined distance, it is possible to prevent erroneous judgments when, for example, an end on a side other than the end that was cut last time becomes close (i.e., when the overall length of the cable to be removed becomes shorter).

[0021] Alternatively, conversely, by obtaining distance information to the signal reflecting section at each end of the cable, and determining that the cable cannot be cut if the longer distance information is greater than or equal to a predetermined distance, it is possible to reduce erroneous judgments when the cable has been cut and removed, for example to the vicinity of a control panel, etc.

[0022] For example, when a cable that is not a target for removal and has one end connected to a control panel or the like and the other end connected to equipment is selected, the distance to the control panel is close, so the distance information for the shorter end is less than the specified distance, but the distance to the connection part with the equipment is long, so the distance information for the longer end is greater than the specified distance. On the other hand, when a cable that is a target for removal and has one end connected to a control panel or the like and the other end that has already been cut is selected, the distance to the control panel and the distance to the cut part are both close, so both the distance information for the shorter end and the longer end are less than the specified distance. This makes it possible to suppress erroneous judgments.

[0023] In addition, the clamp section detects whether the cable is in an energized state, and if the energization detection section determines that the cable is in an energized state, it determines that the cable cannot be cut, thereby preventing the cable from being cut while in use.

[0024] In addition, by changing the display color of the lamp serving as the cut-off possibility transmission section depending on whether the cut-off possibility state is indicated or not, it is possible to easily grasp whether the cut-off possibility state is indicated or not.

[0025] The second invention is a cut cable determination device for determining whether a cable is to be removed, the cut cable determination device having a fixing section for fixing to an existing cable cutter, a clamping section capable of clamping the cable midway, a signal input section in the clamping section capable of inputting a signal from midway through the cable, and a signal receiving section capable of receiving a reflected signal reflected by a signal reflecting section at the end of the cable, and is equipped with a TDR measurement section capable of measuring the distance between the signal input section and the signal reflecting section from the time from signal transmission to reception of the reflected signal, a determination section for determining whether the cable connected to the TDR measurement section can be cut, and a cut feasibility transmission section connected to the determination section for transmitting whether the cable can be cut to a user, wherein the determination section determines that the cable can be cut when the distance information measured by the TDR measurement section is less than a predetermined distance, and outputs a message that the cable can be cut to the user via the cut feasibility transmission section.

[0026] According to the second aspect of the present invention, by fixing the device to an existing cable cutter, for example, it is possible to determine a cable to be removed and prevent erroneous cutting. Effect of the Invention

[0027] According to the present invention, it is possible to provide a cable cutter and the like that has good workability and is capable of cutting a cable without erroneous cutting. [Brief description of the drawings]

[0028] [Figure 1] FIG. 2 shows a cable cutter 1. [Diagram 2] 1A and 1B are diagrams showing a configuration of a cable cutter 1. [Diagram 3] 1 is a conceptual diagram showing the cable cutter 1 in use. [Figure 4] 1A is a conceptual diagram showing the use of the cable cutter 1, and FIG. 1B is a conceptual diagram showing the measurement state of the TDR measuring instrument. [Diagram 5] 4 is a flowchart showing the processing steps of the cable cutter 1. [Figure 6]10 is a flowchart showing other processing steps of the cable cutter 1. [Figure 7] 10 is a flowchart showing still another processing step of the cable cutter 1. [Figure 8] 5A to 5C are diagrams showing another configuration of the cable cutter 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] A preferred embodiment of the present invention will be described in detail below with reference to the drawings. Fig. 1 is a side view of a cable cutter 1 for cutting a cable to be removed. The cable cutter 1 is mainly composed of a clamp unit 3, a cutter 5, a main body unit 7, a display unit 9, etc. The clamp unit 3 is disposed on one end side of the main body unit 7. The clamp unit 3 can be opened and closed, and by opening the clamp unit 3 to open a part of it, it is possible to clamp the cable midway along the cable. Furthermore, when the clamp unit 3 is closed, it becomes annular, and it is possible to arrange the cable so that it passes through the annular clamp unit 3.

[0030] Similarly to the clamp unit 3, a cutter 5 capable of opening and closing is disposed at one end of the main body 7. The cutter 5 is normally open, but by operating the cutter 5, it is possible to cut the cable that has passed through the clamp unit 3 and been clamped. The clamp unit 3 and the cutter 5 may be operated manually or electrically. In this case, the clamp unit 3 and the cutter 5 are operated by respective operation units 11 or the like provided on the main body 7. In the illustrated example, the operation unit 11 is a lever type provided on the main body 7, but the operation unit 11 may be a button type operation panel or a touch panel such as a liquid crystal panel.

[0031] A display unit 9 is disposed on the main body unit 7. The display unit 9 functions as a cut-possible / invisible communication unit that communicates to the user whether or not the cable can be cut, which will be described later. For example, the display unit 9 may be a lamp that emits light in different colors, and the cut-possible state and the uncut-possible state may be distinguished by the different display colors of the lamp. Note that, as long as the display unit 9 functions as a cut-possible / invisible communication unit, it does not necessarily have to be a lamp, and may, for example, be displayed on a display panel, or may be distinguished by a sound such as a buzzer.

[0032] 2 is a block diagram showing the configuration of the cable cutter 1. The cable cutter 1 has a TDR measurement unit 13, a cut-possibility determination unit 23, a cut-possibility transmission unit 21, etc. The TDR measurement unit 13 is also composed of a signal input unit 17, a signal receiving unit 19, a distance calculation unit 15, etc. TDR is a method of applying a high-speed pulse or step signal to a wiring or the like and observing the reflected waveform that returns. The distance from the measurement unit to the reflecting unit can be calculated from the time it takes for this reflected waveform to return.

[0033] In this embodiment, the signal input unit 17 can input a pulse signal to the cable clamped by the clamp unit 3. That is, the signal input unit 17 is built into the clamp unit 3 and can input a signal from the middle of the cable. Note that various methods have been proposed for inputting a signal to a cable from the middle rather than from the end of the cable. For example, the CC-33 transmission clamp (product name) by Goodman Corporation is not a TDR device, but is used as a device that clamps the cable midway and can input a signal to the cable.

[0034] Signal receiving unit 19 operates on the same principle as signal input unit 17, but in the opposite manner to signal input unit 17, and can receive a pulse signal from a cable clamped by clamp unit 3. That is, signal receiving unit 19 is built into clamp unit 3, and can receive a reflected signal that is input by signal input unit 17 and reflected by a signal reflecting unit on the end side of the cable. Note that signal receiving unit 19 and signal input unit 17 may be built into the same clamp unit 3, or may be built into each of a pair of clamp units provided side by side.

[0035] Distance calculation unit 15 calculates the distance between signal input unit 17 (i.e., the position of clamp unit 3) and the signal reflecting unit (i.e., the end of the cable) from the time from when signal input unit 17 transmits a signal to when the reflected signal is received by signal receiving unit 19. In this way, TDR measurement unit 13 can measure the distance from the position of cable cutter 1 to the end of the cable.

[0036] A cut-off feasibility determination unit 23 that determines whether or not the cable can be cut is connected to the TDR measurement unit 13. The cut-off feasibility determination unit 23 is, for example, a CPU, and determines whether or not the cable is a cable to be removed based on the length information to the cable end obtained by the TDR measurement unit 13, and determines whether or not the cable can be cut. The determination method of the cut-off feasibility determination unit 23 will be described later in detail.

[0037] The disconnection feasibility transmission unit 21 is connected to the disconnection feasibility determination unit 23. As described above, when the disconnection feasibility determination unit 23 determines that the cable can be cut (i.e., the cable is a target for removal), the disconnection feasibility transmission unit 21 displays an indication accordingly on the display unit 9, and when the disconnection feasibility determination unit 23 determines that the cable cannot be cut (i.e., the cable is not a target for removal), the disconnection feasibility transmission unit 21 displays an indication accordingly on the display unit 9. Note that, as described above, the method of transmitting the determination result of the disconnection feasibility transmission unit 21 to the user is not particularly limited.

[0038] Next, a method of using the cable cutter 1 will be described. Fig. 3 is a schematic diagram showing the use of the cable cutter 1. For example, many cables 29 are connected to a control panel 27, and the cables 29 are arranged in a cable rack 31 or the like. Each cable 29 arranged in the cable rack 31 is connected to a piece of equipment or the like to which it is to be connected. Note that the cables 29 are not limited to those connected to the control panel 27 as shown in the figure, and may be signal lines or power cables.

[0039] Here, a case will be described where, when removing the disposal facility 25, the cable 29 connected to the disposal facility 25 is removed together with the disposal facility 25. In this case, for example, the cable 29 is cut near the disposal facility 25 (point A in the figure). If the control panel 27 is close to the cut part, it is possible to pull out the cable 29 from the cable rack 31, but if the cable 29 is long, it is difficult to pull out the cable 29 in one go in this manner. For this reason, the target cable 29 is cut and pulled out again at a position, for example, about 10 m away from the cut position (a length that allows the cable 29 to be pulled out), and this is repeated to remove the cable 29 over its entire length.

[0040] 4(a) is a conceptual diagram showing a state in which cable 29 is clamped by clamp unit 3 of cable cutter 1. As described above, cable 29 is clamped midway through the cable at a position about 10 m from the cut position. At this time, the distance (L1 in the figure) from the clamp position to the position where cable 29 was previously cut is approximately 10 m. Meanwhile, the other end of cable 29 is connected to control panel 27 or the like.

[0041] In this state, the TDR measurement unit 13 of the cable cutter 1 is operated. Fig. 4(b) is a conceptual diagram showing the measurement results by the TDR measurement unit 13. As described above, the distance is calculated based on the time from when a signal is input to the cable 29 until the reflected signal returns. Therefore, the time (distance) until the first reflected signal pulse appears corresponds to the distance from the cable cutter 1 to the end of the cable 29 (i.e., L1).

[0042] On the other hand, the other end of the cable 29 is not necessarily a cut part, but is connected to another member, for example, via a connector. For example, in the illustrated example, even if the control panel 27 is connected to a fuse or relay via a terminal or the like, a part of the signal is reflected at this connection. Therefore, the second reflected signal pulse is determined to be a reflected signal from the other end. For example, if this distance is L2, the TDR measurement unit 13 detects L1, which is a short distance, and L2, which is a long distance, from the reflected signal.

[0043] FIG. 5 is a flowchart showing the operation of the disconnection possibility determination unit 23 when performing the measurement in this manner. As described above, the TDR measurement unit 13 calculates the distance from the measurement unit to the reflector from the input pulse signal and the received pulse signal (step 100), and the disconnection possibility determination unit 23 displays that disconnection is possible on the display unit 9 when the obtained distance information (minimum distance (L1 in FIG. 4(b))) is equal to or less than a predetermined distance (for example, 10 m or less) (steps 101, 102). On the other hand, when the minimum distance (L1 in FIG. 4(b)) exceeds a predetermined distance (for example, more than 10 m or 15 m or more), the disconnection possibility determination unit 23 outputs that disconnection is not possible on the display unit 9 (steps 101, 104). The above-mentioned predetermined distance for disconnection possibility determination can be arbitrarily set by the user. In addition, it may be possible to select from a plurality of lengths (conditions) set in advance.

[0044] Note that the control unit (not shown) may release the operation control of the cutter 5 only when the cutting feasibility determination unit 23 determines that cutting is possible (step 103). In other words, when the cutting feasibility determination unit 23 determines that cutting is not possible, the cutter 5 may be controlled not to operate. Note that the operation control of the cutter 5 may be performed, for example, mechanically by a pin or the like to prevent it from operating, or the operation may be controlled on an electric circuit.

[0045] By repeating the above operations, the target cable 29 can be cut and removed at intervals of, for example, about 10 m.

[0046] In this way, according to this embodiment, when the distance to the cutting portion is shorter than a predetermined distance, it is possible to identify the cable 29 as the cable to be cut. Therefore, it is possible to identify the target cable 29 for each predetermined distance, and cut and remove the cable 29. In addition, it is not necessary to move the cable cutter 1 along the cable 29 with the cable 29 to be removed penetrated through the clamp portion 3. This results in good workability.

[0047] Furthermore, the cuttability determination unit 23 acquires distance information (L1 and L2) to the signal reflecting parts at each end of the cable 29, and determines that the cable can be cut if the shorter distance information (L1) is equal to or shorter than a predetermined distance, so that the determination can be made based only on the distance to the end on the cut side. Therefore, the determination can be made regardless of the energization state of the cables 29 other than the one to be removed.

[0048] When the cutoff feasibility determination unit 23 determines that cutoff is possible, the display unit 9 displays the determination result, making it easy to understand the result. Even when the cutoff feasibility determination unit 23 determines that cutoff is not possible, the display unit 9 displays the determination result, making it possible to more reliably understand the result of the pass / fail determination.

[0049] It should be noted that the method of determining whether or not to disconnect by the disconnection possibility determination unit 23 is not limited to the above method. Fig. 6 is a flowchart showing another determination method. In this embodiment as well, first, the TDR measurement unit 13 calculates the distance from the measurement unit to the reflection unit from the input pulse signal and the received pulse signal (step 200), and the disconnection possibility determination unit 23 determines whether the obtained minimum distance (L1 in Fig. 4(b)) is equal to or less than a predetermined distance (for example, equal to or less than 10 m) (step 201).

[0050] Next, the cutting feasibility determination unit 23 determines whether the second distance (L2 in FIG. 4(b)) obtained by the TDR measurement unit 13 is equal to or shorter than a predetermined distance (e.g., 10 m or shorter) (step 202). If the minimum distance is equal to or shorter than the predetermined distance and the second distance exceeds the predetermined distance, the cutting feasibility determination unit 23 determines that cutting is possible and causes the display unit 9 to display that cutting is possible (step 203). In this case, the cutting feasibility determination unit 23 releases the operation control of the cutter 5 (step 204).

[0051] Meanwhile, cut-off possibility determination unit 23 acquires distance information to the signal reflecting parts in the direction of each end of cable 29, and determines that the cable cannot be cut if the minimum distance exceeds a predetermined distance or if the longer distance information is equal to or less than the predetermined distance. That is, cut-off possibility determination unit 23 determines that the cable cannot be cut if the minimum distance exceeds a predetermined distance or if the second distance is equal to or less than the predetermined distance, and causes display unit 9 to display that the cable cannot be cut (step 205). The above-mentioned predetermined distances for determining whether or not L1 and L2 can be cut can be set arbitrarily by the user, or can be selected from a plurality of lengths (conditions) set in advance.

[0052] The reason for this determination is as follows: For example, as shown in Fig. 4(a), when the cable 29 to be removed is cut from one end, the cut position gradually approaches the control panel 27. That is, the distance L1 and the distance L2 become closer to each other.

[0053] In this state, it is not possible to clearly distinguish between L1 and L2, so it is necessary to check whether the distance to the cut portion is short or the distance to the control panel 27 on the other end is short. For this reason, for example, when the distance to each end is less than a predetermined distance, it is determined that cutting is not possible in order to warn the worker and call his / her attention. Note that when the total length becomes short, it is also possible to pull out the cable 29 in the cable rack 31. For this reason, in this case, it is also possible to visually determine and cut the desired cable 29 without using the length measuring function of the TDR measuring unit 13 of the cable cutter 1.

[0054] Moreover, the method of determining whether or not to disconnect by the disconnection possibility determination unit 23 may be another method. Fig. 7 is a flowchart showing another determination method. In this embodiment, too, first, the TDR measurement unit 13 calculates the distance from the measurement unit to the reflection unit from the input pulse signal and the received pulse signal (step 300), and the disconnection possibility determination unit 23 determines whether the obtained minimum distance (L1 in Fig. 4(b)) is equal to or less than a predetermined distance (for example, equal to or less than 10 m) (step 301).

[0055] Next, the cutting feasibility determination unit 23 determines whether the second distance (L2 in FIG. 4(b)) obtained by the TDR measurement unit 13 is equal to or shorter than a predetermined distance (e.g., 15 to 20 m or shorter) (step 302). If the minimum distance is equal to or shorter than the predetermined distance and the second distance is also equal to or shorter than the predetermined distance, the cutting feasibility determination unit 23 determines that cutting is possible and causes the display unit 9 to display that cutting is possible (step 303). In this case, the cutting feasibility determination unit 23 releases the operation control of the cutter 5 (step 304).

[0056] On the other hand, the cut-off possibility determination unit 23 acquires distance information to the signal reflecting parts in the direction of each end of the cable 29, and determines that the cable cannot be cut if the minimum distance exceeds the predetermined distance or if the longer distance information is equal to or greater than the predetermined distance. That is, the cut-off possibility determination unit 23 determines that the cable cannot be cut if the minimum distance exceeds the predetermined distance or if the second distance exceeds the predetermined distance, and causes the display unit 9 to display that the cable cannot be cut (step 305). Even in this case, the above-mentioned predetermined distances for determining whether or not the cable can be cut for each of L1 and L2 may be arbitrarily set by the user, or may be selectable from a plurality of lengths (conditions) set in advance. The reason for this determination is as follows.

[0057] For example, as shown in Fig. 4(a), when the cable 29 to be removed is cut from one end, the cut position gradually approaches the control panel 27. That is, the distance L1 and the distance L2 become closer. That is, as the cable 29 to be removed approaches the control panel 27, both L1 and L2 become shorter.

[0058] On the other hand, the cables 29 that are not the target of removal are close to the control panel 27, but the other ends are not cut and are wired to other equipment, etc. For this reason, for the cables 29 that are not the target of removal, the shortest distance is the distance to the control panel 27, and the second distance is the distance to the equipment, etc. on the other end side. That is, in the vicinity of the control panel 27, for the cables that are not the target of removal, the distance to the control panel 27 is less than the distance to the end (connection) on the other end side. For this reason, in the area close to the control panel 27 (for example, a distance of about 15 to 20 m), the distance to the other end is long for cables other than those that have been cut up until now. For this reason, if the second distance is long, it is determined that the cable is not the target of removal (i.e., a cable that has not been cut), and is determined not to be cut.

[0059] 6 and 7 are completely opposite to each other, but they may be switched at any timing. That is, the device may be operated in each of the determination modes depending on the usage situation. Also, the display on the display unit 9 may be different between the display in step 203 and the display in step 303 (or the display in step 205 and the display in step 305).

[0060] Furthermore, cuttable / non-cuttable determination unit 23 may detect the electrified state of cable 29 and use this for the determination. Fig. 8 is a diagram showing a configuration in which electrification detection unit 33 is arranged. Electrical conduction detection unit 33 is arranged in clamp unit 3, and is capable of detecting whether cable 29 passing through clamp unit 3 is in an electrified state. When electrification detection unit 33 determines that cable 29 is in an electrified state, cuttable / non-cuttable determination unit 23 determines that cable 29 cannot be cut. In this case, the method of display on display unit 9 may be further changed.

[0061] Furthermore, the cable cutter 1 can obtain distance information at that location each time a cutting operation is performed. Therefore, this distance information can be accumulated and used as a criterion for the cuttability determination unit 23. For example, the initially obtained distance information (L10, L20) to each end is stored in a memory unit built into the cable cutter 1, and when the next cutting operation (TDR measurement) is performed, the distance information (L11, L21) to each end at that time is stored in the memory unit, and the difference between L11+L21 and L20 is calculated as distance information, and if this is less than a predetermined value (for example, within ±1 m), it can be determined that cutting is possible. In other words, the cable length after the previous cut and the cable length measured this time can be compared, and this can be added to the criterion for determination. Note that, when L1 n +L2 n and L2 n-1 The cut-off determination criteria for the difference between the lengths may be arbitrarily set by the user, or may be selectable from a plurality of lengths (conditions) set in advance.

[0062] Also, the length cut so far may be accumulated and stored in a memory unit, and when this exceeds a predetermined distance (for example, half of the original cable length), the judgment method shown in Fig. 6 may be automatically switched to the judgment method shown in Fig. 7. In other words, when the remaining cable length becomes short, the judgment criteria may be switched.

[0063] In addition, when the cable 29 is cut, the reflected signal at the cut portion and the reflected signal at the connection portion with, for example, a connector, have different intensities. For example, the pulse signal is almost entirely reflected at the cut end, but at the connection portion with the terminal, a part of the reflected signal is reflected, and the remaining part propagates further beyond the connector. For this reason, the cutability determination unit 23 may determine the intensity of the reflected signal instead of only the distance information, and may use the reflected signal to distinguish whether it is a reflection at the cut end or a reflection at a connection portion with other equipment such as the control panel 27 for the determination. In other words, only the distance information to the cut end may be used for the determination. In this case, only the distance to one end of the cable (the cut end) can be detected, and the distance to the other end (the connection portion with the control panel, etc.) can be eliminated as noise, so there is no need to determine the two distances (L1, L2) as described above, and it is possible to determine whether or not the cut can be performed only based on whether the detected distance (L1) is equal to or less than a predetermined distance.

[0064] Furthermore, for example, when a large number of cables 29 are arranged on the cable rack 31 and it is difficult to find the desired cable 29, the multiple cables 29 may be clamped together in the clamp unit 3 and a similar operation may be performed. In this case, all reflected signals from both ends of each cable 29 are acquired, but if, for example, the minimum distance L1 exceeds a predetermined distance, it may be determined that none of the clamped cables 29 are to be removed, and if the minimum distance L1 is equal to or less than the predetermined distance, the group may be divided into smaller cables 29, and the same operation may be repeated to identify the target cable 29.

[0065] Also, the TDR measurement unit 13 (clamp unit 3), the cuttable / non-cuttable determination unit 23, and the cuttable / non-cuttable transmission unit 21 may be configured separately from the cutter 5 and may be detachable from the cutter 5 (and the cutter operation unit). For example, the main body (main body having the configurations of Figs. 2 and 8) of the cut cable determination machine including the TDR measurement unit 13 (including the clamp unit 3), the cuttable / non-cuttable determination unit 23, and the cuttable / non-cuttable transmission unit 21 (and the operation unit 11, etc.) may be attachable to an existing cable cutter. In this case, the cut cable determination machine is fixed to the existing cable cutter so that the clamp unit 3 and the cutter part of the cable cutter are arranged side by side (i.e., so that the cable to be determined by the cut cable determination machine and the cable to be cut are arranged on the same axis). Note that the method of fixing the cut cable determination machine to the existing cable cutter is not particularly limited, but the cut cable determination machine may have a fixing unit that can be fixed to the existing cable cutter, such as a bolt or a band.

[0066] Although the preferred embodiment of the present invention has been described above with reference to the accompanying drawings, the present invention is not limited to such an example. It is clear that a person skilled in the art can come up with various modified or altered examples within the scope of the technical ideas disclosed in this application, and it is understood that such examples also naturally belong to the technical scope of the present invention. [Explanation of symbols]

[0067] 1... Cable cutter 3...Clamp section 5………Cutter 7...Main body 9……Display section 11……Operation unit 13. TDR measurement section 15...Distance calculation section 17: Signal input section 19... Signal receiving section 21....Disconnection transmission section 23……Cutability determination unit 25... Disposal facility 27………Control panel 29………Cable 31………Cable rack 33...Electricity detection section

Claims

1. A cable cutter for cutting a cable to be removed, a TDR measurement unit having a clamping unit capable of clamping a cable midway, a signal input unit in said clamping unit capable of inputting a signal from midway along the cable, and a signal receiving unit capable of receiving a reflected signal reflected by a signal reflecting unit at an end of the cable, said TDR measurement unit being capable of measuring the distance between said signal input unit and said signal reflecting unit from the time from signal transmission to reception of the reflected signal; a cutter capable of cutting the cable clamped by the clamp portion; a determination unit for determining whether or not a cable connected to the TDR measurement unit can be disconnected; a disconnection possibility notification unit connected to the determination unit and notifying a user of whether the cable can be disconnected; Equipped with The cable cutter is characterized in that the judgment unit determines that the cable can be cut when the distance information measured by the TDR measurement unit is less than a predetermined distance, and outputs a message to a user that the cable can be cut via the cutability transmission unit.

2. 2. The cable cutter according to claim 1, wherein the determination unit acquires distance information to the signal reflecting unit at each end of the cable, and determines that the cable can be cut if the shorter distance information is less than a predetermined distance.

3. 3. The cable cutter according to claim 2, wherein the determination unit acquires distance information to the signal reflecting unit at each end of the cable, and if the longer distance information is less than a predetermined distance, determines that the cable cannot be cut.

4. 3. The cable cutter according to claim 2, wherein the determination unit acquires distance information to the signal reflecting unit at each end of the cable, and if the longer distance information is equal to or greater than a predetermined distance, determines that the cable cannot be cut.

5. 2. The cable cutter according to claim 1, further comprising: a current detection unit in the clamping portion capable of detecting whether the cable is in a current-carrying state; and when the current detection unit determines that the cable is in a current-carrying state, the determination unit determines that the cable cannot be cut.

6. 2. The cable cutter according to claim 1, wherein the cuttable / non-cuttable signaling unit is a lamp, and the lamp displays different colors depending on whether the cable is in a cuttable state or not.

7. A cut cable determination device for determining a cable to be removed, A fixing part for fixing to an existing cable cutter, a TDR measurement unit having a clamping unit capable of clamping a cable midway, a signal input unit in said clamping unit capable of inputting a signal from midway along the cable, and a signal receiving unit capable of receiving a reflected signal reflected by a signal reflecting unit at an end of the cable, said TDR measurement unit being capable of measuring the distance between said signal input unit and said signal reflecting unit from the time from signal transmission to reception of the reflected signal; a determination unit for determining whether or not a cable connected to the TDR measurement unit can be disconnected; a disconnection possibility notification unit connected to the determination unit and notifying a user of whether the cable can be disconnected; Equipped with The determination unit determines that the cable can be cut when the distance information measured by the TDR measurement unit is less than a predetermined distance, and outputs a message indicating that the cable can be cut to a user via the cut / non-cut transmission unit.

Images