Heat generation detection device

Abstract

To provide a heat generation detection device for accurately identifying a short circuit portion, in considering a resistance value between first and second conductors in a short circuit portion.SOLUTION: A short circuit position detection device 12 for detecting a short circuit portion BW of a first conductor B and a second conductor W comprises: a switch S comprising at least one opening / closing contact point S1, S2. The switch S is configured to form at least three and different two-terminal circuits 9 by switching a connection form of a first branch A1, a second branch A2, a third branch A3, so that the first branch A1 having a first resistance value R1, the second branch A2 having a second resistance value R2, and the third branch A3 having a third resistance value R3 are included in at least one two-terminal circuit 9.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a heat detection device that detects heat generation in an object to be detected by detecting a short circuit caused by softening of the insulator due to heat between a first conducting wire and a second conducting wire arranged adjacent to each other along an object to be detected, with an insulator that softens at a preset temperature in between. [Background technology]

[0002] When detecting heat generation of the detection target due to the short-circuit state between the first and second conductors as described above, it is preferable to identify the location where the short-circuit state has occurred, in consideration of the recovery of the detection target. Japanese Patent Application Laid-Open No. 10-20334 discloses a technique for identifying the location where the short-circuit state has occurred. Specifically, a probe is connected to one end of the first conductor and the second conductor, and a resistance value "r0" from one end of the first conductor to one end of the second conductor via the short-circuit location is measured. If the resistance value between one end of the first conductor and the short-circuit location is "R1", the resistance value between the first conductor and the second conductor at the short-circuit location is "r", and the resistance value between one end of the second conductor and the short-circuit location is "R2", the measured resistance value is "R1+r+R2". Here, the line length between one end of the first conductor and the short-circuit location and the line length between one end of the second conductor and the short-circuit location are approximately equal, so that it can be considered that "R1=R2". In this document, the resistance value "r" at the short-circuit point is considered to be sufficiently small compared to "R1" and "R2", and is approximated as zero, "r0 = 2·R1". Since the line length "L0" of the first conductor and second conductor and the resistance value "R0" of the entire line are known, the length "x" from one end of the first conductor (similarly for one end of the second conductor) to the short-circuit point is "x = (R1 / R0)·L0". [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 10-20334 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when the first conducting wire and the second conducting wire are in a "short-circuited state", various contact states between the first conductor and the second conductor at the short-circuited point are possible, and the resistance value may also take various values. For example, when the insulator between the first conducting wire and the second conducting wire is not softened, the first conducting wire and the second conducting wire may be in a "short-circuited state" with a relatively large resistance value. Even in such a case, it is preferable to be able to quickly detect the heat generation of the detection target and accurately identify the short-circuited point, which is the heat generation point. However, when the resistance value between the first conductor and the second conductor at the short-circuited point is considered to be zero as described above, the error generated in the estimated short-circuited point becomes large.

[0005] In view of the above background, it is desirable to provide a technique for accurately identifying a short-circuit location while also taking into account the resistance value between the first conducting wire and the second conducting wire at the short-circuit location. [Means for solving the problem]

[0006] In view of the above, a heat generation detection device includes a first conducting wire having a first contact point and a second contact point at each end, and a second conducting wire having a third contact point and a fourth contact point at each end, the first conducting wire and the second conducting wire being disposed along an object to be detected in a state adjacent to each other with an insulator that softens at a preset temperature therebetween, the first conducting wire and the second conducting wire being disposed along the object to be detected when the first conducting wire and the second conducting wire are short-circuited due to softening of the insulator by heat, and the heat generation detection device includes a short circuit location detection device that detects a location of a short circuit between the first conducting wire and the second conducting wire, the short circuit location detection device being configured to detect the first contact point, the second conducting wire, a first object contact selected from at least one of the first contact, the second contact, the third contact, and the fourth contact; a second object contact selected from at least one of the first contact, the second contact, the third contact, and the fourth contact, excluding the first object contact; a reference resistor connected to at least one of a positive electrode and a negative electrode; a first reference contact which is a contact connected to the positive electrode or a contact connected to the positive electrode via the reference resistor; a second reference contact which is a contact connected to the negative electrode or a contact connected to the negative electrode via the reference resistor; a voltage detector that detects an object voltage, which is a voltage between the object contact and the voltage detector, and a switch having at least one open / close contact, wherein the switch switches an electrical connection between at least each of the first contact, the second contact, the third contact, and the fourth contact, and each of the first reference contact and the second reference contact, to switch a circuit configuration of a two-terminal circuit having the first object contact and the second object contact as terminals, and when the first conducting wire and the second conducting wire are in a short-circuited state at the short-circuit location, the switch switches the contact of the first conducting wire at the short-circuit location as a first short circuit. a contact point of the second conductor at the short-circuit location is a second short-circuit point, branches having a first resistance value which can be regarded as being the same value, a branch from the first contact point to the first short-circuit point and a branch from the third contact point to the second short-circuit point are referred to as a first branch, branches having a second resistance value which can be regarded as being the same resistance value, a branch from the first short-circuit point to the second contact and a branch from the second short-circuit point to the fourth contact are referred to as a second branch, and a branch formed between the first short-circuit point and the second short-circuit point and having a third resistance value is referred to as a third branch,The second branch and the third branch are included in at least one of the two-terminal circuits, and the connection forms of the first branch, the second branch, and the third branch are switched to form at least three different two-terminal circuits.

[0007] According to this configuration, at least three two-terminal circuits can be created by switching the connection state between the first and second conductors and the first reference contact on the positive side and the second reference contact on the negative side by the switch. Since each two-terminal circuit includes at least one of the unknown first resistance value, second resistance value, and third resistance value, the three unknown resistance values ​​can be obtained by simultaneous equations based on the three different two-terminal circuits. By identifying the third resistance value, which can take various values ​​depending on the form of the short circuit at the short-circuit location, the values ​​of the first resistance value and the second resistance value can also be identified with high accuracy. Since the resistance value of the conductor is linear with the length of the conductor, the short-circuit location can be estimated with high accuracy by identifying the first resistance value and the second resistance value, which are the resistance values ​​of the conductor. That is, according to this configuration, the short-circuit location can be identified with high accuracy by also taking into account the resistance value between the first and second conductors at the short-circuit location.

[0008] Further features and advantages of the fever detection device will become apparent from the following description of exemplary and non-limiting embodiments thereof, which are illustrated in the drawings. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a front view showing an example of an article transport vehicle; [Diagram 2] FIG. 1 is a circuit block diagram showing a schematic configuration example of a short circuit detection device in a heat generation detection device; [Diagram 3] Equivalent circuit of a heat-sensing wire when a short circuit occurs in the heat-sensing wire [Figure 4] FIG. 7 is a circuit block diagram showing a first example of a two-terminal circuit formed by selection using the same switches as those in FIGS. 5 and 6. [Diagram 5] FIG. 7 is a circuit block diagram showing a second example of a two-terminal circuit formed by selection using the same switches as those in FIGS. 4 and 6. [Figure 6] FIG. 6 is a circuit block diagram showing a third example of a two-terminal circuit formed by selection using the same switches as those in FIGS. 4 and 5. [Figure 7] FIG. 7 shows examples of three different types of two-terminal circuits and combined resistors formed by selection using switches having different configurations from those shown in FIGS. 4 to 6. [Figure 8] FIG. 8 shows examples of three different types of two-terminal circuits and combined resistors formed by selection using switches having different configurations from those shown in FIGS. 4 to 7. [Figure 9] An equivalent circuit showing an example of a circuit having a switch capable of forming the two-terminal circuit shown in FIGS. 10 to 12. [Figure 10] A diagram showing a two-terminal pair circuit (four-terminal circuit) from which a two-terminal circuit is formed by switching the connection configuration of the first, second, and third branches. [Figure 11] FIG. 1 shows several examples of two-terminal circuits in which one of the first contact, the second contact, the third contact, and the fourth contact is selectively connected to a first target contact that detects a target voltage. [Figure 12] FIG. 1 shows several examples of two-terminal circuits in which two of the first, second, third, and fourth contacts are selectively connected to a first target contact that detects a target voltage. [Figure 13] FIG. 1 shows several examples of two-terminal circuits in which three of the first, second, third and fourth contacts are selectively connected to a first target contact that detects a target voltage. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the fever detection device will be described with reference to the drawings. The fever detection device is used, for example, in an article transport facility 100 equipped with an article transport vehicle 50. As shown in Fig. 1, the article transport facility 100 includes a power feeder 8 arranged along a traveling rail 52 that forms a movement path 51 of the article transport vehicle 50 and that supplies power to the article transport vehicle 50 in a non-contact manner, and a heat-sensitive wire 3 arranged along the power feeder 8.

[0011] The article transport vehicle 50 illustrated in this embodiment includes a traveling section 59 that travels along a travel path 51 while being guided by a pair of travel rails 52 arranged and supported by being suspended from the ceiling, a transport vehicle body 53 located below the travel rails 52 and supported by being suspended from the traveling section 59, and a power receiving device 40 that receives driving power in a non-contact manner from a power supply line 8 arranged along the travel path 51. The transport vehicle body 53 includes an article support section (not shown) that is provided on the transport vehicle body 53 so as to be capable of being raised and lowered and that supports an article in a suspended state. Articles to be transported by the article transport vehicle 50 include, for example, FOUPs (Front Opening Unified Pods) that accommodate semiconductor substrates and glass substrates that are materials for displays.

[0012] The running unit 59 is provided with a pair of running wheels 55 that are rotated by an electric drive motor 54. The running wheels 55 roll on a running surface formed by the upper surface of each of the running rails 52. The running unit 59 is also configured to include a drive motor 54 for running and its drive circuit, etc., and causes the article transport vehicle 50 to travel along the running rails 52. The transport vehicle body 53 is provided with an actuator that raises and lowers the article support unit, an actuator that drives the gripping unit that grips articles, etc., and their drive circuits, etc.

[0013] Power for these drive motors 54, various actuators, and the drive circuits that drive them is supplied contactlessly to the power receiving device 40 from a power supply line 8. In this embodiment, the power supply line 8 that supplies drive power to the article transport vehicle 50 via the power receiving device 40 is arranged on both sides of the power receiving device 40 in the path width direction perpendicular to the travel path 51 along the horizontal plane.

[0014] In this embodiment, the power receiving device 40 receives power from the power supply line 8 using wireless power supply technology and supplies driving power to the goods transport vehicle 50. A high-frequency current flows through the power supply line 8, which is an induction line, and a magnetic field is generated around the power supply line 8. The power receiving device 40 is configured with a pickup coil 41 and a magnetic core, and the pickup coil 41 induces power by electromagnetic induction from the magnetic field. The induced AC power is converted to DC by a rectifier circuit such as a full-wave rectifier circuit and a power receiving circuit (not shown) including a smoothing capacitor, and is supplied to the actuator and the driving circuit.

[0015] As shown in FIG. 1, the heat-sensitive wire 3 includes a pair of conductors 1 (first conductor B, second conductor W) covered with an insulator 2 that softens at a preset temperature. Each conductor 1 is configured as a covered conductor wire in which a core wire 1c formed of a conductor is covered with an insulator 2. The heat-sensitive wire 3 including the pair of conductors 1 is formed by twisting the two conductors 1, the first conductor B and the second conductor W, into a so-called twisted pair and further covering the twisted wire with a covering material 3d. The first conductor B and the second conductor W are the same member manufactured according to the same specifications, and have the same resistance value per unit length except for errors such as individual differences. The first conductor B and the second conductor W also have the same total length in the heat-sensitive wire 3 except for errors.

[0016] As shown in FIG. 2, the first conductor B has a first contact B1 and a second contact B2 at both ends, and the second conductor W has a third contact W1 and a fourth contact W2 at both ends. One end (first contact B1) of the first conductor B and one end (third contact W1) of the second conductor W at one end of the heat-sensing wire 3 are connected to the positive electrode side (Vp) and the negative electrode side (ground) of the short-circuit detection device 11, respectively. The other end (second contact B2) of the first conductor B and the other end (fourth contact W2) of the second conductor W at the other end of the heat-sensing wire 3 are connected to each other via a relay 6, which will be described later. In addition, "Rr" in FIG. 2 is a current limiting resistor that limits the current flowing between the positive and negative poles. That is, the heat-sensing wire 3 is connected between the positive electrode (Vp) and the negative electrode (ground) in the following order: the positive electrode (Vp), a current limiting resistor Rr, a first conducting wire B, a relay 6, a second conducting wire W, and ground.

[0017] The pair of conductors 1 formed as a twisted wire are configured such that when the insulator 2 softens, the core wires 1c formed of a conductor come into contact with each other and short-circuit. The covering material 3d is made of a material that does not soften even at the temperature at which the insulator 2 softens. Therefore, even if the insulator 2 softens, the heat-sensitive wire 3 including the pair of conductors 1 is covered with the covering material 3d, so that the core wire 1c is prevented from being exposed to the outside. The power supply line 8 also includes a power supply line main body 8c (core wire) formed of a conductor, and a covering 8d formed of an insulator that covers the power supply line main body 8c.

[0018] The heat-sensing wire 3 is arranged near the power feeder 8, preferably in close contact with the power feeder 8, along the power feeder 8. When the temperature of the power feeder 8 rises, the insulator 2 softens as described above, and the core wires 1c come into contact with each other without being insulated, resulting in a short circuit. Note that the "short circuit state" is not limited to a state in which the resistance between the core wires 1c of the first conducting wire B and the second conducting wire W is zero, but is also an extremely low state (a state in which the resistance is equal to or less than a predetermined resistance value). The short circuit detection device 11 can detect an abnormality (a temperature rise in this case) in the power feeder 8 by detecting that a short circuit has occurred (= a short circuit has occurred) while the heat-sensing wire 3 is energized.

[0019] In this embodiment, the short circuit detection device 11 is mounted on the same board as the short circuit position detection device 12, which will be described later with reference to, for example, Figs. 4 to 9. The control device 7 is also mounted on the board, or the control device 7 is connected to the board. The control device 7 has some of the functions of the short circuit detection device 11 and some of the functions of the short circuit position detection device 12. It is preferable that the control device 7 is configured with a microcomputer as its core. Of course, the short circuit detection device 11 and the short circuit position detection device 12 may be mounted on different boards, or the short circuit detection device 11 and the short circuit position detection device 12 may be connected to different control devices 7. In any case, it is preferable that the wiring of the first conductor B and the second conductor W is switched between when they are connected to the short circuit detection device 11 and when they are connected to the short circuit position detection device 12. For example, after the short circuit detection device 11 detects that the heat sensitive wire 3 is short-circuited, the short circuit position detection device 12 may be connected to the heat sensitive wire 3 instead of the short circuit detection device 11 to identify the location where the short circuit has occurred.

[0020] When the heat-sensitive wire 3 is energized and not short-circuited, the current flows from the positive pole (Vp) through the current-limiting resistor Rr, the first conductor B, the coil of the relay 6, the second conductor W, and the ground. For example, if the relay 6 is an a-contact type, when the contact of the relay 6 is closed by this current, the two terminals of the control device 7 to which both ends of the contact of the relay 6 are connected become conductive. Here, when the heat-sensitive wire 3 is short-circuited, the current flows through the short-circuited part. That is, the current flows from the positive pole (Vp) through the current-limiting resistor Rr, the first conductor B, the short-circuited part, the second conductor W, and the ground, and stops flowing through the relay 6. As a result, when the contact of the relay 6 is opened, the two terminals of the control device 7 to which both ends of the contact of the relay 6 are connected also become non-conductive.

[0021] The control device 7 can thereby detect that the heat-sensing wire 3 has been short-circuited, that is, that the first conducting wire B and the second conducting wire W have been short-circuited. The relay 6 functions as a short-circuit detector. Then, the control device 7 or a control device other than the control device 7 (for example, an equipment control device of the article conveying equipment 100 or a control device of a power supply system that supplies power to the power supply line 8) can determine that heat is being generated in the power supply line 8. That is, the heat detection device 10 detects that the first conducting wire B and the second conducting wire W, which are adjacent to each other with the insulator 2 that softens at a preset temperature therebetween and arranged along the detection target (here, the power supply line 8), have been short-circuited due to the softening of the insulator 2 due to heat, thereby detecting heat generation in the detection target (the power supply line 8).

[0022] When heat generation in the power supply line 8 is detected due to a short circuit between the first conductor B and the second conductor W, the operation of the power supply system and the article conveying equipment 100 is temporarily stopped and recovery work is carried out. Considering the lead time until recovery, it is preferable to also identify the location where the heat-sensing wire 3 is short-circuited, i.e., the location where heat is generated in the power supply line 8. For this reason, the heat detection device 10 further includes a short circuit position detection device 12 (see Figures 4 to 9, etc.) that detects the short circuit location BW between the first conductor B and the second conductor W.

[0023] FIG. 3 shows an equivalent circuit of the heat-sensing wire 3 when a short circuit occurs in the heat-sensing wire 3. When the first conductor B and the second conductor W are in a short-circuit state at the short-circuit point BW, the contact point of the first conductor B at the short-circuit point BW is the first short-circuit point B3, and the contact point of the second conductor W at the short-circuit point BW is the second short-circuit point W3. The first short-circuit point B3, the second short-circuit point W3, and the above-mentioned first contact B1, second contact B2, third contact W1, and fourth contact W2 are contacts (nodes) in the equivalent circuit. In addition, the branch (arm or branch) from the first contact B1 to the first short-circuit point B3 and the branch from the third contact W1 to the second short-circuit point W3 are the first branch A1. As shown in the equivalent circuit of FIG. 3, the branch from the first contact B1 to the first short-circuit point B3 and the branch from the third contact W1 to the second short-circuit point W3 are branches having a first resistance value R1 that can be regarded as being the same value, and are referred to as the "first branch A1" with the same name. Also, the branch from the first short-circuit point B3 to the second contact B2 and the branch from the second short-circuit point W3 to the fourth contact W2 are referred to as the second branch A2 with the same value. As shown in the equivalent circuit of FIG. 3, the branch from the first short-circuit point B3 to the second contact B2 and the branch from the second short-circuit point W3 to the fourth contact W2 are branches having a second resistance value R2 that can be regarded as being the same value, and are referred to as the "second branch A2" with the same name. Also, the branch formed between the first short-circuit point B3 and the second short-circuit point W3 and having a third resistance value R3 is referred to as the third branch A3.

[0024] Here, for example, the resistance value (R1+R3+R1) between one end (first contact B1) of the first conducting wire B and one end (third contact W1) of the second conducting wire W, and the resistance value (R1+R3+R2) between one end (first contact B1) of the first conducting wire B and the other end (fourth contact W2) of the second conducting wire W are measured. If the third resistance value R3, which is the resistance value at the short-circuit point BW, is considered to be zero, the resistance value between the first contact B1 and the third contact W1 is "R1+R1", and the resistance value between the first contact B1 and the fourth contact W2 is "R1+R2". Therefore, the "first resistance value R1" can be obtained from the resistance value between the first contact B1 and the third contact W1, and the "second resistance value R2" can be obtained from the first resistance value R1 and the resistance value between the first contact B1 and the fourth contact W2.

[0025] The total resistance value of the first conductor B (resistance value between the first contact B1 and the second contact B2) and the total resistance value of the second conductor W (resistance value between the third contact W1 and the fourth contact W2) can be considered to be equal, and this resistance value is known and is "R1+R2." In addition, since the length and resistance value of the conductor 1 are linear, the first short-circuit point B3 and the second short-circuit point W3 can be estimated and the short-circuit location BW can be identified based on the ratio between the first resistance value R1 and the second resistance value R2.

[0026] However, when the first conductor B and the second conductor W are in a "short-circuited state", various states are possible for the form of contact between the first conductor B and the second conductor W at the short-circuited portion BW, and various resistance values ​​are also possible. For example, when the insulator 2 between the first conductor B and the second conductor W is softened slowly, the first conductor B and the second conductor W may be in a "short-circuited state" with a relatively large resistance value. Even in such a case, it is preferable to quickly detect the heat generation in the power supply line 8 and accurately identify the short-circuited portion BW, which is the heat generation portion. However, when the third resistance value R3, which is the resistance value between the first conductor B and the second conductor W at the short-circuited portion, is considered to be zero as described above, an error occurs in the estimated short-circuited portion. The heat generation detection device 10 of the present embodiment is configured to include a short-circuit position detection device 12 that can accurately identify the short-circuited portion BW by taking into account the third resistance value R3, which is the resistance value between the first conductor B and the second conductor W at the short-circuited portion BW.

[0027] For example, in the article transport facility 100 exemplified in this embodiment, the first conductor B and the second conductor W tend to have long overall lengths. In addition, when the article transport vehicle 50 is an overhead transport vehicle, the power supply line 8 and the heat-sensing wire 3 are also disposed at a high position relative to the floor, as described above with reference to FIG. 1. In other words, the first conductor B and the second conductor W are often installed in a location where they cannot be easily seen. Therefore, particularly in the case of the article transport facility 100 exemplified in this embodiment, it is very useful to provide the short-circuit position detection device 12 so as to be able to identify the location where the heat-sensing wire 3 is short-circuited, that is, the location where the temperature of the power supply line 8 is high.

[0028] For these reasons, the present embodiment illustrates an example of a heat generation detection device 10 that detects heat from the power feeder 8 in the article conveying equipment 100. However, the object of heat generation detection is not limited to the power feeder 8. Naturally, the equipment or device equipped with the heat generation detection device 10 is not limited to the article conveying equipment 100.

[0029] The following description will be given with reference to Figures 4 to 6. The equivalent circuit illustrated in Figure 3 includes a first object contact t1, a second object contact t2, a first reference junction Q1, and a second reference junction Q2, as shown in Figure 4 etc. The short circuit position detection device 12 includes a voltage detector 5 and a switch S in addition to the first object contact t1, the second object contact t2, the first reference junction Q1, and the second reference junction Q2.

[0030] The first object contact t1 is a contact selected from at least one of the first contact B1, the second contact B2, the third contact W1, and the fourth contact W2. The second object contact t2 is a contact selected from at least one of the first contact B1, the second contact B2, the third contact W1, and the fourth contact W2, excluding the first object contact t1.

[0031] The reference resistor Rref is a resistor connected to at least one of the positive electrode P (reference voltage Vref) and the negative electrode N (ground) of the short-circuit position detection device 12. FIG. 4 and other figures illustrate a configuration in which the reference resistor Rref is connected to the positive electrode P, but the reference resistor Rref may be connected to the negative electrode N, or one reference resistor Rref may be connected to each of the positive electrode P and the negative electrode N. In this case, the reference resistor Rref connected to the positive electrode P and the reference resistor Rref connected to the negative electrode N may have the same resistance value or different resistance values. The reference voltage Vref is divided by a "composite resistor (first composite resistor Ra, second composite resistor Rb, third composite resistor Rc)" to be described later and the reference resistor Rref. The voltage appearing across the composite resistor is the target voltage Vout to be detected. The positive electrode P may be the same as the positive electrode (Vp) of the short-circuit detection device 11, and the negative electrode N may be the same as the negative electrode (ground) of the short-circuit detection device 11.

[0032] The first reference junction Q1 is a junction set on the side of the positive pole P, and is a junction connected to the positive pole P or a junction connected to the positive pole P via a reference resistor Rref. The second reference junction Q2 is a junction set on the side of the negative pole N, and is a junction connected to the negative pole N or a junction connected to the negative pole N via a reference resistor Rref. The target voltage Vout is a voltage detected to identify the short-circuit point BW, and is a voltage between the first target junction t1 and the second target junction t2. As shown in FIG. 4 and other figures, in this embodiment, since the second target junction t2 is a junction connected to the negative pole N, the target voltage Vout is a voltage between the first target junction t1 and the ground. The voltage detector 5 detects the target voltage Vout. Although FIGS. 4 to 6 illustrate an example in which the voltage detector 5 is, for example, a voltage sensor, this is conceptual and does not necessarily have to include a voltage sensor. For example, when the control device 7 includes a microcomputer having a functional unit capable of determining the voltage value of an analog signal, such as an A / D converter, the microcomputer can be the voltage detector 5. In particular, when the object voltage Vout is the voltage between the first object junction t1 and the ground as in this embodiment, it is easy to detect the voltage value using such a microcomputer.

[0033] The switch S has at least one open / close contact (the first contactor S1 and the second contactor S2 shown in FIG. 4 to FIG. 6). As shown in FIG. 8, the switch S may further have a third contactor S3, which will be described in detail later. As shown in FIG. 9, the switch S may further have a first contactor SB1, a second contactor SB2, a third contactor SW1, and a fourth contactor SW2, which will be described in detail later. That is, the switch S switches the circuit configuration of the two-terminal circuit 9 having the first object contact t1 and the second object contact t2 as terminals by switching the electrical connections between at least the first contact B1, the second contact B2, the third contact W1, and the fourth contact W2, and the first reference contact Q1 and the second reference contact Q2, respectively. Various configurations will be described below as examples. The switch S is configured to be capable of forming at least three different two-terminal circuits 9 by switching the connection configuration of the first branch A1, the second branch A2, and the third branch A3 so that the first branch A1, the second branch A2, and the third branch A3 are included in at least one two-terminal circuit 9.

[0034] In the configurations shown in Figs. 4 to 6, the switch S is configured to include a first contactor S1 and a second contactor S2. The configuration in which the switch S is configured to include two contactors is one of the configurations in which the number of contactors included in the switch S is the smallest. The first contactor S1 is a contactor that can connect and disconnect the second contact B2 and the negative pole N (ground), and the second contactor S2 is a contactor that can connect and disconnect the second contact B2 and the fourth contact W2. In addition, the second contact B2 and the fourth contact W2 can also be connected to the negative pole N (ground) by cooperation between the first contactor S1 and the second contactor S2. Figs. 4 to 6 show examples in which different two-terminal circuits 9 are configured by changing the open / closed states of the first contactor S1 and the second contactor S2, respectively.

[0035] In Fig. 4 to Fig. 6, the arrows indicate the direction of the current. In the configurations shown in Fig. 4 to Fig. 6, the first object contact t1 is fixed to the first contact B1, and the first contact B1 is connected to the first reference contact Q1. Therefore, the voltage of the first contact B1 is the object voltage Vout. The second object contact t2 includes at least the third contact W1. In other words, the third contact W1 is fixed to the second object contact t2. When the first contactor S1 is in the closed state, the second contact B2 is also the second object contact t2. When the first contactor S1 and the second contactor S2 are in the closed state, the second contact B2 and the fourth contact W2 are also the second object contact t2.

[0036] As described above, the second contactor S2 is a contactor capable of disconnecting the connection between the second contact B2 and the fourth contact W2. That is, the switch S may further include an open / close contact capable of connecting two contacts of different conductors 1 among the first contact B1, the second contact B2, the third contact W1, and the fourth contact W2 to each other in addition to the open / close contacts for switching the electrical connection between each of the first contact B1, the second contact B2, the third contact W1, and the fourth contact W2 and each of the first reference contact Q1 and the second reference contact Q2. As will be described later with reference to FIG. 9, the open / close contact capable of connecting two contacts of different conductors 1 to each other may include the first jumper J1, the second jumper J2, the third jumper J3, and the fourth jumper J4. The second contactor S2 shown in FIG. 4 to FIG. 6 is an open / close contact corresponding to the second jumper J2 in the embodiment shown in FIG. 9.

[0037] In the configuration shown in Fig. 4, the first contactor S1 is in an open state and the second contactor S2 is in a closed state. The combined resistance (first combined resistance Ra) of the formed two-terminal circuit 9 (same as No. 8 in Fig. 11) is expressed by the following formula (1).

[0038]

number

[0039] 4, the target voltage Vout to be detected is the voltage between the positive pole P and the negative pole N divided by the reference resistor Rref and the first combined resistor Ra. Since the value of the current that can flow through the reference resistor Rref is the same as the value of the current that flows through the first combined resistor Ra, the following formula (2) is established.

[0040]

number

[0041] Since the target voltage Vout is detected by the voltage detector 5 and the resistance value of the reference resistor Rref is known, the value of the first combined resistance Ra can be obtained by the following formula (3). The same is true for the second combined resistance Rb and the third combined resistance Rc described later with reference to Figures 5 and 6, and it is clear that "Ra" in formula (3) should be read as "Rb" and "Rc", respectively.

[0042]

number

[0043] 5, the first contactor S1 is in a closed state and the second contactor S2 is in an open state. The combined resistance (second combined resistance Rb) of the formed two-terminal circuit 9 (same as No. 5 in FIG. 11) is expressed by the following formula (4).

[0044]

number

[0045] 6, the first contactor S1 and the second contactor S2 are both open. The combined resistance (third combined resistance Rc) of the formed two-terminal circuit 9 (same as No. 3 in FIG. 11) is expressed by the following formula (5).

[0046]

number

[0047] The short-circuit position detection device 12 can determine the first resistance value R1, the second resistance value R2, and the third resistance value R3 by solving the simultaneous equations of equations (1), (4), and (5) using the values ​​of the first combined resistance Ra, the second combined resistance Rb, and the third combined resistance Rc obtained based on equation (3).

[0048] That is, the short circuit position detection device 12 calculates the combined resistances (first combined resistance Ra, second combined resistance Rb, and third combined resistance Rc) of at least three different two-terminal circuits 9 based on the reference voltage Vref, which is the voltage between the positive pole P and the negative pole N, the resistance value of the reference resistor Rref, and the target voltage Vout (Equation (3)). Then, the short circuit position detection device 12 calculates the first resistance value R1, the second resistance value R2, and the third resistance value R3 based on the multiple combined resistances (first combined resistance Ra, second combined resistance Rb, and third combined resistance Rc). The first resistance value R1 is the resistance value of the first branch A1, and the second resistance value R2 is the resistance value of the second branch A2, and the first conductor B and the second conductor W have the first branch A1 and the second branch A2. Therefore, the short circuit location BW can be estimated based on at least one of the first resistance value R1 and the second resistance value R2.

[0049] In one embodiment, the short circuit position detection device 12 can estimate the short circuit location BW based on the resistance values ​​per unit length of the first conductor B and the second conductor W and the first resistance value R1 or the second resistance value R2. Alternatively, the short circuit position detection device 12 may estimate the short circuit location BW based on the total length of the first conductor B and the second conductor W and the ratio of the first resistance value R1 to the second resistance value R2. Since there is linearity between the length of the conductor 1 and the resistance value of the conductor 1, the short circuit location BW can be estimated with high accuracy.

[0050] As described above, the short circuit position detection device 12 calculates the combined resistances (first combined resistance Ra, second combined resistance Rb, third combined resistance Rc) of at least three different two-terminal circuits 9, and calculates the first resistance value R1, the second resistance value R2, and the third resistance value R3 based on the multiple combined resistances (first combined resistance Ra, second combined resistance Rb, third combined resistance Rc). The switch S only needs to have an open / close contact so that at least three different two-terminal circuits 9 can be configured. Although Figs. 4 to 6 show an example in which a jumper (second contactor S2) is also provided as an open / close contact, it is of course possible to have only open / close contacts that switch electrical connections between the first contact B1, the second contact B2, the third contact W1, and the fourth contact W2, and the first reference contact Q1 and the second reference contact Q2, without providing a jumper. Figs. 7 and 8 show an example in which electrical connections are switched by a switch S that does not include a jumper as an open / close contact.

[0051] FIG. 7 shows an example of a circuit configuration that can configure three different two-terminal circuits 9 with the smallest number of open / close contacts without including jumpers. In this example, the first contactor S1 selectively connects and disconnects the third contact W1 and the second reference contact Q2 (ground), and the second contactor S2 selectively connects and disconnects the second contact B2 and the second reference contact Q2 (ground). When the first contactor S1 and the second contactor S2 are both in a closed state, the same two-terminal circuit 9 as No. 5 and FIG. 5 in FIG. 11 is formed. When the first contactor S1 is in a closed state and the second contactor S2 is in an open state, the same two-terminal circuit 9 as No. 3 and FIG. 6 in FIG. 11 is formed. When the first contactor S1 is in an open state and the second contactor S2 is in an open state, the same two-terminal circuit 9 as No. 1 in FIG. 11 is formed.

[0052] 8 shows an example of a circuit configuration that does not include jumpers and can configure three different two-terminal circuits 9 with the simplest combined resistance. In this example, the switch S has three open / close contacts, a first contactor S1 selectively connects and disconnects the third contact W1 and the second reference contact Q2 (ground), a second contactor S2 selectively connects and disconnects the fourth contact W2 and the second reference contact Q2 (ground), and a third contactor S3 selectively connects and disconnects the second contact B2 and the second reference contact Q2 (ground).

[0053] When the first contactor S1 is in a closed state, the second contactor S2 is in an open state, and the third contactor S3 is in a closed state, the same two-terminal circuit 9 as No. 3 in Fig. 11 and Fig. 6 is formed. When the first contactor S1 is in an open state, the second contactor S2 is in an open state, and the third contactor S3 is in a closed state, the same two-terminal circuit 9 as No. 1 in Fig. 11 is formed. When the first contactor S1 is in an open state, the second contactor S2 is in a closed state, and the third contactor S3 is in an open state, the same two-terminal circuit 9 as No. 2 in Fig. 11 is formed.

[0054] As described above with reference to Fig. 4 to Fig. 8, the short circuit location detection device 12 can appropriately identify the short circuit location BW if it is configured to form at least three different two-terminal circuits 9 by switching the connection forms of the first branch A1, the second branch A2, and the third branch A3 by the switch S so that at least one two-terminal circuit 9 includes the first branch A1 having the first resistance value R1, the second branch A2 having the second resistance value R2, and the third branch A3 having the third resistance value R3. The short circuit location detection device 12 may be configured to form at least three of the two-terminal circuits 9 that can be formed from the equivalent circuit in the short-circuit state as shown in Fig. 3. According to the inventors, 58 such two-terminal circuits 9 can be formed, as exemplified in Figs. 11 to 13.

[0055] 9 illustrates a switch S having open / close contacts capable of forming any one of 58 possible two-terminal circuits 9. Here, the switch S has eight open / close contacts: a first contactor SB1, a second contactor SB2, a third contactor SW1, a fourth contactor SW2, a first jumper J1, a second jumper J2, a third jumper J3, and a fourth jumper J4.

[0056] The first contactor SB1 exclusively connects the first contact B1 to the first reference contact Q1 and the second reference contact Q2 in two different closed states, and opens the first contact B1 in the open state. Similarly, the second contactor SB2 exclusively connects the second contact B2 to the first reference contact Q1 and the second reference contact Q2 in the closed state, and opens the second contact B2 in the open state. Similarly, the third contactor SW1 exclusively connects the third contact W1 to the first reference contact Q1 and the second reference contact Q2 in the closed state, and opens the third contact W1 in the open state. Similarly, the fourth contactor SW2 exclusively connects the fourth contact W2 to the first reference contact Q1 and the second reference contact Q2 in the closed state, and opens the second contact B2 in the open state.

[0057] It can be said that the first contactor SB1, the second contactor SB2, the third contactor SW1, and the fourth contactor SW2 have make-and-break contacts that are connected to the first reference contact Q1 and the second reference contact Q2, although they are exclusive. Therefore, the short circuit position detection device 12 shown in Fig. 9 has eight switches (four switches each having one make-and-break contact and four switches each having two make-and-break contacts), and can be said to have 12 make-and-break contacts.

[0058] The first jumper J1, the second jumper J2, the third jumper J3, and the fourth jumper J4 are switches each having a single make-and-break contact. The first jumper J1 makes and breaks the connection between the first contact B1 and the third contact W1. The second jumper J2 makes and breaks the connection between the second contact B2 and the fourth contact W2. The third jumper J3 makes and breaks the connection between the first contact B1 and the fourth contact W2. The fourth jumper J4 makes and breaks the connection between the second contact B2 and the third contact W1.

[0059] As is apparent from the above description with reference to Figures 4 to 8, so long as the minimum number of two-terminal circuits 9, three, can be formed, it is clear that the switch S does not need to have all of the open / close contacts as shown in Figure 9. Therefore, it goes without saying that the short circuit position detection device 12 does not need to have a switch S with all of the open / close contacts shown in Figure 9.

[0060] FIG. 10 shows a two-terminal pair circuit (four-terminal circuit) from which a two-terminal circuit 9 is formed by switching the connection forms of the first branch A1, the second branch A2, and the third branch A3. FIG. 11 to FIG. 13 show 58 different connection forms when forming a two-terminal circuit from this two-terminal pair circuit. In FIG. 11 to FIG. 13, the arrows indicate the direction of the current. When the rear end of the arrow is located at the first junction B1, the second junction B2, the third junction W1, or the fourth junction W2, it indicates that the corresponding junction is connected to the first reference junction Q1. That is, the rear end of the arrow corresponds to the first object junction t1 where the object voltage Vout appears. On the other hand, when the tip of the arrow is located at the first junction B1, the second junction B2, the third junction W1, or the fourth junction W2, it indicates that the corresponding junction is connected to the second reference junction Q2 (ground). In addition, when two of the first contact B1, the second contact B2, the third contact W1, and the fourth contact W2 are shown in black and the two contacts are connected by a line, it indicates that the two contacts are connected by either the first jumper J1, the second jumper J2, the third jumper J3, or the fourth jumper J4.

[0061] Figure 11 shows an example of a circuit in which only one of the first contact B1, second contact B2, third contact W1, and fourth contact W2 is the first object contact t1. No. 1 to No. 9 are circuit examples in which the first contact B1 is the first object contact t1. No. 10 to No. 18 are circuit examples in which the second contact B2 is the first object contact t1. No. 19 to No. 27 are circuit examples in which the third contact W1 is the first object contact t1. No. 28 to No. 36 are circuit examples in which the fourth contact W2 is the first object contact t1.

[0062] FIG. 12 shows a circuit example in which two of the first contact B1, second contact B2, third contact W1, and fourth contact W2 are the first object contact t1. No. 37 to No. 39 are circuit examples in which the first contact B1 and second contact B2 are the first object contact t1. No. 40 to No. 42 are circuit examples in which the first contact B1 and fourth contact W2 are the first object contact t1. No. 43 to No. 45 are circuit examples in which the first contact B1 and third contact W1 are the first object contact t1. No. 46 to No. 48 are circuit examples in which the second contact B2 and fourth contact W2 are the first object contact t1. No. 49 to No. 51 are circuit examples in which the second contact B2 and third contact W1 are the first object contact t1. No. 52 to No. 54 are circuit examples in which the third contact W1 and fourth contact W2 are the first object contact t1.

[0063] FIG. 13 shows a circuit example in which three of the first contact B1, second contact B2, third contact W1, and fourth contact W2 become the first object contact t1. No. 55 is a circuit example in which the first contact B1, second contact B2, and third contact W1 become the first object contact t1. No. 56 is a circuit example in which the first contact B1, second contact B2, and fourth contact W2 become the first object contact t1. No. 57 is a circuit example in which the first contact B1, third contact W1, and fourth contact W2 become the first object contact t1. No. 58 is a circuit example in which the second contact B2, third contact W1, and fourth contact W2 become the first object contact t1.

[0064] [Summary of this embodiment] The fever detection device described above will be briefly summarized below.

[0065] In one embodiment, a heat detection device includes a first conducting wire having a first contact point and a second contact point at each end, and a second conducting wire having a third contact point and a fourth contact point at each end, the first conducting wire and the second conducting wire being arranged along an object to be detected and adjacent to each other with an insulator that softens at a preset temperature therebetween, the first conducting wire and the second conducting wire being arranged along the object to be detected when the first conducting wire and the second conducting wire are short-circuited due to softening of the insulator by heat, and the heat detection device detects heat generated by the object to be detected, and further includes a short circuit position detection device that detects a short-circuit location between the first conducting wire and the second conducting wire, the short circuit position detection device being configured to detect the first contact point, a first object contact selected from at least one of the second contact, the third contact, and the fourth contact; a second object contact selected from at least one of the first contact, the second contact, the third contact, and the fourth contact, excluding the first object contact; a reference resistor connected to at least one of a positive electrode and a negative electrode; a first reference contact which is a contact connected to the positive electrode or a contact connected to the positive electrode via the reference resistor; a second reference contact which is a contact connected to the negative electrode or a contact connected to the negative electrode via the reference resistor; a voltage detector that detects an object voltage between the first and second object contacts, and a switch having at least one open / close contact, wherein the switch switches an electrical connection between at least each of the first contact, the second contact, the third contact, and the fourth contact, and each of the first reference contact and the second reference contact, to switch a circuit configuration of a two-terminal circuit having the first object contact and the second object contact as terminals, and when the first conducting wire and the second conducting wire are in a short-circuited state at the short-circuited location, the switch switches the contact of the first conducting wire at the short-circuited location to a first reference contact. a branch from the first contact point to the first short-circuit point and a branch from the third contact point to the second short-circuit point are referred to as a first branch; branches having a first resistance value which can be regarded as being the same value as each other, a branch from the first short-circuit point to the second contact point and a branch from the second short-circuit point to the fourth contact are referred to as a second branch; branches having a second resistance value which can be regarded as being the same value as each other, a branch from the first short-circuit point to the second contact point and a branch from the second short-circuit point to the fourth contact are referred to as a second branch; and a branch formed between the first short-circuit point and the second short-circuit point and having a third resistance value is referred to as a third branch;The second branch and the third branch are included in at least one of the two-terminal circuits, and the connection forms of the first branch, the second branch, and the third branch are switched to form at least three different two-terminal circuits.

[0066] According to this configuration, at least three two-terminal circuits can be created by switching the connection state between the first and second conductors and the first reference contact on the positive side and the second reference contact on the negative side by the switch. Since each two-terminal circuit includes at least one of the unknown first resistance value, second resistance value, and third resistance value, the three unknown resistance values ​​can be obtained by simultaneous equations based on the three different two-terminal circuits. By identifying the third resistance value, which can take various values ​​depending on the form of the short circuit at the short-circuit location, the values ​​of the first resistance value and the second resistance value can also be identified with high accuracy. Since the resistance value of the conductor is linear with the length of the conductor, the short-circuit location can be estimated with high accuracy by identifying the first resistance value and the second resistance value, which are the resistance values ​​of the conductor. That is, according to this configuration, the short-circuit location can be identified with high accuracy by also taking into account the resistance value between the first and second conductors at the short-circuit location.

[0067] Preferably, the switch further includes an open / close contact that is capable of connecting two contacts of different conductors among the first contact, the second contact, the third contact, and the fourth contact to each other.

[0068] With this configuration, a greater variety of two-terminal circuits can be formed compared to switching the electrical connections between each of the first contact, the second contact, the third contact, and the fourth contact and each of the first reference junction and the second reference junction.

[0069] In addition, it is preferable that the short-circuit position detection device calculates a combined resistance of at least three different two-terminal circuits based on the voltage between the positive electrode and the negative electrode, the resistance value of the reference resistor, and the target voltage, calculates the first resistance value, the second resistance value, and the third resistance value based on the multiple combined resistances, and estimates the short-circuit location based on at least one of the first resistance value and the second resistance value.

[0070] Since each two-terminal circuit includes at least one of the unknown first resistance value, second resistance value, and third resistance value, the three unknown resistance values ​​can be obtained by a simultaneous equation based on the three different composite resistance values. Since the third resistance value, which can take various values ​​depending on the form of the short circuit at the short circuit location, is specified, the values ​​of the first resistance value and the second resistance value can also be specified with high accuracy. Since the first resistance value and the length of the first branch, and the second resistance value and the length of the second branch have linearity, as do the total resistance value and total length of the first conductor and the second conductor, the values ​​of the first resistance value and the second resistance value are specified, and the lengths of the first branch and the second branch can also be specified with high accuracy. Therefore, the short circuit location can be specified with high accuracy.

[0071] It is also preferable that the short circuit position detection device estimates the location of the short circuit based on an overall length of the first conducting wire and the second conducting wire and a ratio between the first resistance value and the second resistance value.

[0072] Since there is linearity between the length of the conductor and the resistance of the conductor, the ratio of the first resistance to the second resistance is equivalent to the ratio of the length of the first branch to the length of the second branch of the first conductor, and is equivalent to the ratio of the length of the first branch to the length of the second branch of the second conductor. Therefore, with this configuration, the short-circuit location can be accurately estimated.

[0073] It is also preferable that the short circuit position detection device estimates the location of the short circuit based on the resistance values ​​per unit length of the first conducting wire and the second conducting wire, and the first resistance value or the second resistance value.

[0074] Since there is linearity between the length of the conductor and the resistance of the conductor, the relationship between the resistance per unit length and the first resistance is linear with the length of the first branch, and the relationship between the resistance per unit length and the second resistance is linear with the length of the second branch. Therefore, with this configuration, it is possible to accurately estimate the location of the short circuit. [Explanation of symbols]

[0075] 2: Insulator 5: Voltage detector 8: Power supply line (detection target) 9 :2 terminal circuit 10: Fever detection device 12: Short circuit location detection device A1: First branch A2:Second branch A3: Third branch B: 1st conductor B1: First contact B2: 2nd contact B3: First short circuit point BW: Short circuit location J1: First jumper (open / close contact) J2: Second jumper (open / close contact) J3: 3rd jumper (open / close contact) J4: 4th jumper (open / close contact) N: Negative electrode P: Positive electrode Q1: First reference junction Q2: Second reference junction R1: First resistance R2: Second resistance value R3: Third resistor value Ra: 1st combined resistance (combined resistance) Rb: 2nd combined resistance (combined resistance) Rc: 3rd combined resistance (combined resistance) Rref: Reference resistor S: Switch S1: First contactor (switching contact) S2: Second contactor (switching contact) S3: Third contactor (switching contact) SB1: First contact point (open / close contact) SB2: Second contact point (open / close contact) SW1: Third contact point contactor (open / close contact) SW2: 4th contact point (open / close contact) Vout: Target voltage Vref: Reference voltage (voltage between positive and negative poles) W: 2nd conductor W1: Third contact W2: Fourth contact W3: Second short circuit point t1: First target contact t2: Second target contact

Claims

1. a first conductor having a first contact and a second contact at each end; a second conducting wire having a third contact and a fourth contact at each end, A heat generation detection device that detects heat generation in a detection object by detecting a short circuit caused by softening of an insulator by heat between a first conducting wire and a second conducting wire that are adjacent to each other and sandwich an insulator that softens at a preset temperature, the first conducting wire and the second conducting wire being short-circuited due to softening of the insulator by heat, a short circuit location detection device for detecting a short circuit location between the first conducting wire and the second conducting wire, The short circuit position detection device includes: a first target contact selected from at least one of the first contact, the second contact, the third contact, and the fourth contact; a second target contact selected from at least one of the first contact, the second contact, the third contact, and the fourth contact, excluding the first target contact; A reference resistor connected to at least one of the positive electrode and the negative electrode; a first reference junction that is a junction connected to the positive electrode or a junction connected to the positive electrode via the reference resistor; a second reference junction which is a junction connected to the negative electrode or a junction connected to the negative electrode via the reference resistor; a voltage detector for detecting a target voltage, the target voltage being a voltage between the first target contact and the second target contact; a switch having at least one make and break contact; the switch switches at least an electrical connection between each of the first contact, the second contact, the third contact, and the fourth contact, and each of the first reference junction and the second reference junction, to switch a circuit configuration of a two-terminal circuit having the first object contact and the second object contact as terminals; When the first conducting wire and the second conducting wire are in a short-circuited state at the short-circuit location, a contact point of the first conducting wire at the short-circuit location is defined as a first short-circuit point; a contact point of the second conducting wire at the short-circuited portion is defined as a second short-circuit point; a branch having a first resistance value that can be regarded as being the same as each other, the branch from the first contact point to the first short-circuit point and the branch from the third contact point to the second short-circuit point being defined as a first branch; branches having a second resistance value that can be regarded as being the same resistance value, the branch from the first short-circuit point to the second contact and the branch from the second short-circuit point to the fourth contact being second branches; a branch formed between the first short point and the second short point and having a third resistance value is defined as a third branch, The switch is A fever detection device configured to be capable of forming at least three different two-terminal circuits by switching the connection configuration of the first branch, the second branch, and the third branch so that the first branch, the second branch, and the third branch are included in at least one of the two-terminal circuits.

2. The fever detection device according to claim 1 , wherein the switch further comprises an opening / closing contact capable of connecting two of the first contact, the second contact, the third contact, and the fourth contact that are of different conductors to each other.

3. The short circuit position detection device includes: Calculating a combined resistance of at least three different two-terminal circuits based on the voltage between the positive electrode and the negative electrode, the resistance value of the reference resistor, and the target voltage; calculating the first resistance value, the second resistance value, and the third resistance value based on a plurality of the combined resistances; The heat generation detection device according to claim 1 , wherein the location of the short circuit is estimated based on at least one of the first resistance value and the second resistance value.

4. 4. The heat generation detection device according to claim 3, wherein the short circuit position detection device estimates the location of the short circuit based on an overall length of the first conducting wire and the second conducting wire and a ratio between the first resistance value and the second resistance value.

5. 4. The heat detection device according to claim 3, wherein the short circuit position detection device estimates the location of the short circuit based on a resistance value per unit length of the first conducting wire and the second conducting wire and the first resistance value or the second resistance value.

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