Resistance measurement device and resistance measurement method

Abstract

The resistance measuring device includes a connection structure portion including a group of first contact portions in contact with a first member and a second member, and a group of second contact portions in contact with different portions of the second member. The resistance measuring device is provided with a storage unit that stores information indicating the relationship between the resistance value between the second contact parts in the group and the temperature of the joint part. The resistance measurement device is provided with a measurement control unit that forms a state in which the measurement unit measures a first resistance value between the group of first contact parts and a state in which the measurement unit measures a second resistance value between the group of second contact parts. The resistance measuring device is provided with: a temperature acquisition unit that acquires the temperature of the joining part on the basis of the measured second resistance value and information stored in the storage unit; and a calculation unit that calculates a reference resistance value on the basis of the acquired temperature and the measured first resistance value.

Description

Technical Field

[0001] The present invention relates to a resistance measuring device and a resistance measuring method. Background Art

[0002] JP1993-115981A discloses a weld diagnostic method that determines the weld state based on the relationship between the input heat obtained from the voltage between electrodes and the surface temperature of the weld measured by a radiation thermometer. Summary of the invention

[0003] However, when the object to be measured is a metal with low emissivity, it is difficult for a radiation thermometer to measure the surface temperature accurately. In addition, a radiation thermometer can only measure the surface temperature of the object to be measured.

[0004] Therefore, for example, when the measured resistance value of the joint is corrected by the temperature of the measurement object to obtain a reference resistance value of the joint at a reference temperature, if the correction is performed based on the temperature measured by the radiation thermometer, the accuracy of the corrected reference resistance value may be reduced.

[0005] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to improve the accuracy of temperature correction.

[0006] A resistance measuring device according to one embodiment of the present invention measures a reference resistance value of a joint at a preset reference temperature in an object formed by mutually joining a first member and a second member, wherein the resistance measuring device comprises: a connecting structure portion comprising a group of first contact portions respectively contacting the first member and the second member and a group of second contact portions contacting different portions of the second member; a measuring portion for measuring the resistance value between the group of first contact portions and the resistance value between the group of second contact portions; a storage portion for storing information indicating the relationship between the resistance value between the group of second contact portions and the temperature of the joint; a measurement control portion for forming a state in which a first resistance value between the group of first contact portions is measured by the measuring portion and a state in which a second resistance value between the group of second contact portions is measured by the measuring portion; a temperature acquisition portion for acquiring the temperature of the joint based on the measured second resistance value and the information stored in the storage portion; and a calculation portion for calculating the reference resistance value based on the acquired temperature of the joint and the measured first resistance value.

[0007] In one embodiment of the present invention, the resistance value between the first contact parts in contact with the first member and the second member and the resistance value between the second contact parts in contact with different parts of the second member are measured by the measuring unit. In addition, information indicating the relationship between the resistance value between the second contact parts and the temperature of the junction of the first member and the second member is stored in the storage unit.

[0008] Then, the temperature of the junction is acquired based on the second resistance value measured by the measuring unit and the information stored in the storage unit, and the reference resistance value is calculated based on the acquired temperature of the junction and the measured first resistance value.

[0009] In this way, the temperature of the joint portion is obtained based on information indicating the relationship between the resistance value between the second contact portions and the temperature of the joint portion. Here, the resistance value between the second contact portions for obtaining the temperature of the joint portion is obtained based on the current passing through the interior of the second member. Therefore, compared with the case where the temperature of the joint portion is measured by a radiation thermometer that can only measure the surface temperature, the temperature of the joint portion can be measured with good accuracy.

[0010] The reference resistance value is calculated based on the acquired temperature of the joint portion and the measured first resistance value between the first contact portions. Therefore, the resistance measuring device can improve the temperature correction accuracy compared to the case where the first resistance value is temperature-corrected based on the surface temperature of the object acquired by the radiation thermometer. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a schematic diagram showing the resistance measuring device according to the first embodiment.

[0012] Figure 2 This is a block diagram showing an example of the hardware configuration of the resistance measuring device.

[0013] Figure 3 This is a functional block diagram showing an example of the functional configuration of the resistance measuring device.

[0014] Figure 4 This is a flowchart showing an example of the pre-processing operation of the resistance measuring device.

[0015] Figure 5 Yes means Figure 4 Flowchart of subsequent actions.

[0016] Figure 6 Yes means Figure 5 Flowchart of subsequent actions.

[0017] Figure 7 It is a graph showing the relationship between the temperature of the junction portion and the second resistance value.

[0018] Figure 8It is an explanatory diagram showing a process of acquiring the temperature of the bonding portion when the first resistance value is measured based on the second resistance values ​​measured before and after the first resistance value is measured.

[0019] Fig. 9 It is a graph showing the relationship between the temperature of the junction portion and the first resistance value.

[0020] Fig.10 This is a flowchart showing an example of the operation of the measurement process of the resistance measurement device.

[0021] Fig.11 This is an explanatory diagram showing the change in the second resistance value with respect to time when the temperature changes from a high temperature to a low temperature.

[0022] Fig.12 It is an explanatory diagram showing a state in which a reference resistance value is obtained from the relationship between the temperature of the junction portion and the first resistance value.

[0023] Fig.13 It is a schematic diagram showing a resistance measuring device according to a second embodiment. DETAILED DESCRIPTION

[0024] (First Embodiment)

[0025] Hereinafter, a first embodiment will be described with reference to the drawings.

[0026] Figure 1 Schematic diagram showing the resistance measuring device 10 according to the first embodiment. Figure 2 2 is a block diagram showing an example of the hardware configuration of the resistance measuring device 10 .

[0027] like Figure 1 As shown, the resistance measuring device 10 is used to measure a reference resistance value R of a joint portion 18 at a preset reference temperature t0 in an object 16 formed by joining a first member 12 and a second member 14 to each other. A0 device.

[0028] (Object)

[0029] The first member 12 and the second member 14 are metal members, and examples of the metal constituting the first member 12 and the second member 14 include copper and aluminum. The first member 12 and the second member 14 may be made of the same metal or different metals.

[0030] The mutually overlapping portions of the first member 12 and the second member 14 are joined by welding, and the joint 18 joining the first member 12 and the second member 14 is constituted by a welded portion. The resistance value of the joint 18 is known to indicate the state of the joint 18, and by knowing the resistance value of the joint 18 at the reference temperature t0, the joint state of the first member 12 and the second member 14 can be known.

[0031] (Connection structure)

[0032] The resistance measuring device 10 includes a connection structure 20 electrically connected to the object 16. The connection structure 20 has a structure including a set of first contact portions (22, 26) contacting the first member 12 and the second member 14, respectively, and a set of second contact portions (24, 26) contacting different portions of the second member 14.

[0033] It should be noted that the group of first contact portions (22, 26) can be, for example, referred to as a group of first contact portions (22, 26). In addition, the group of second contact portions (24, 26) can be, for example, referred to as a group of second contact portions (24, 26).

[0034] In the first embodiment, one first contact portion (26) in the set of first contact portions (22, 26) that contacts the second member 14 is shared with one second contact portion (26) in the set of second contact portions (24, 26). In addition, one first contact portion (26) and one second contact portion (26) are composed of a shared contact portion 26.

[0035] The other first contact portion 22 of the set of first contacts (22, 26) includes a first energizing probe 30 and a first measuring probe 32. The shared contact portion 26 includes a shared first probe 34 and a shared second probe 36. The other second contact portion 24 of the set of second contacts (24, 26) includes a second energizing probe 40 and a second measuring probe 42.

[0036] The first energizing probe 30 contacts and is electrically connected to the first member 12. The first measuring probe 32 contacts and is electrically connected to the first member 12 at a position closer to the bonding portion 18 than the first energizing probe 30.

[0037] The common first probe 34 contacts and is electrically connected to the second member 14. The common second probe 36 contacts and is electrically connected to the second member 14 at a position farther from the bonding portion 18 than the common first probe 34.

[0038] The second measurement probe 42 contacts and is electrically connected to the second member 14. The second energization probe 40 contacts and is electrically connected to the second member 14 at a position farther from the contact position of the shared second probe 36 than the second measurement probe 42.

[0039] Thus, the first measurement probe 32 and the common first probe 34 are arranged at a predetermined interval between the first energizing probe 30 and the common second probe 36. Furthermore, the common second probe 36 and the second measurement probe 42 are arranged at a predetermined interval between the common first probe 34 and the second energizing probe 40.

[0040] It should be noted that, in the first embodiment, the case where the connection structure 20 is composed of a set of first contact portions (22, 26) and a set of second contact portions (24, 26) is described, but the first embodiment is not limited to this. For example, if a set of third contact portions is added, it is also possible to measure the reference resistance value of the junction 18 between the second member 14 and the third member in the object 16 in which the third member is joined to the second member 14 via the junction 18.

[0041] (Measurement Department)

[0042] The resistance measuring device 10 includes a measuring unit 50 for measuring the resistance value between a pair of first contact portions (22, 26) and the resistance value between a pair of second contact portions (24, 26).

[0043] The measuring unit 50 has a configuration for measuring the resistance value of a measurement location of the object 16. There are two-terminal method and four-terminal method as methods for measuring the resistance value, and the measuring unit 50 of the first embodiment measures the resistance value by the four-terminal method.

[0044] The measuring unit 50 includes a supply source 52 for supplying a current to the object 16 and a voltage measuring unit 54 for measuring a voltage value at a predetermined portion of the object 16. The supply source 52 is a constant current source for flowing a constant current. For example, the supply source 52 is realized by a current supply circuit.

[0045] The measuring unit 50 allows a constant current to flow from a supply source 52 to a target part, and measures the voltage of the part through which the current from the supply source 52 flows by the voltage measuring unit 54, thereby being able to measure the resistance value of the target part based on the voltage value measured by the voltage measuring unit 54 and the current value of the current flowing from the supply source 52. Thus, the measuring unit 50 constitutes a measuring circuit capable of measuring the resistance value between the first contact parts (22, 26) forming a group and the resistance value between the second contact parts (24, 26) forming a group.

[0046] In the first embodiment, the supply source 52 is described as a constant current source, but the first embodiment is not limited thereto. For example, the supply source 52 may be composed of a current source that supplies current and a current measuring unit that measures the current flowing from the current source.

[0047] (Switch section)

[0048] The resistance measuring device 10 includes a switching unit 60. For example, the switching unit 60 is realized by a switching circuit.

[0049] The switching unit 60 selectively forms a first connection state in which the first contact parts (22, 26) formed as a group are connected to the measuring unit 50, and a second connection state in which the second contact parts (24, 26) formed as a group are connected to the measuring unit 50. The switching unit 60 is composed of a relay including a first switch 62, a second switch 64, a third switch 66, and a fourth switch 68.

[0050] One terminal 52a of the supply source 52 is connected to the first switch 62 of the switching unit 60. The first current probe 30 is connected to the first contact 62a of the first switch 62, and the common first probe 34 is connected to the second contact 62b of the first switch 62.

[0051] One terminal 54a of the voltage measuring unit 54 is connected to the second switch 64 of the switching unit 60. The first measuring probe 32 is connected to the first contact 64a of the second switch 64, and the common second probe 36 is connected to the second contact 64b of the second switch 64.

[0052] The other terminal 54b of the voltage measuring unit 54 is connected to the third switch 66 of the switching unit 60. The common first probe 34 is connected to the first contact 66a of the third switch 66, and the second measuring probe 42 is connected to the second contact 66b of the third switch 66.

[0053] The other terminal 52b of the supply source 52 is connected to the fourth switch 68 of the switching unit 60. The common second probe 36 is connected to the first contact 68a of the fourth switch 68, and the second current probe 40 is connected to the second contact 68b of the fourth switch 68.

[0054] When the switches 62, 64, 66, 68 are connected to the first contacts 62a, 64a, 66a, 68a, a first connection state is formed in which the first contact portions (22, 26) are connected to the measuring portion 50. When the switches 62, 64, 66, 68 are connected to the second contacts 62b, 64b, 66b, 68b, a second connection state is formed in which the second contact portions (24, 26) are connected to the measuring portion 50.

[0055] like Figure 2 As shown, the resistance measuring device 10 is configured with a processing unit 100 as a center. The processing unit 100 is connected to the measuring unit 50 and the switching unit 60 described above.

[0056] The processing unit 100 controls the signal output to the coil of the relay constituting the switching unit 60 to switch each of the switches 62, 64, 66, 68 (see Figure 1) operates to switch the switching unit 60 to the first connection state or the second connection state. In addition, the processing unit 100 inputs the voltage value measured by the voltage measuring unit 54 of the measuring unit 50, and calculates the resistance value based on the input voltage value and the current value of the current applied from the supply source 52.

[0057] Furthermore, the processing unit 100 is connected to a storage unit 110 , an input unit 112 , a display unit 114 , a notification unit 116 , a clock unit 118 , and a communication unit 120 .

[0058] The storage unit 110 stores data so that the data can be read by the processing unit 100. The storage unit 110 stores a processing program for controlling the operation of the resistance measuring device 10. The storage unit 110 functions as a storage medium for storing a processing program for realizing the functions of the resistance measuring device 10.

[0059] The storage unit 110 is composed of a nonvolatile memory (ROM: Read Only Memory), a volatile memory (RAM: Random Access Memory), etc. The storage unit 110 also stores data to be used in the processing program in a readable manner.

[0060] The storage unit 110 stores the first information 140 (see Figure 7 ), second information 150 (refer to Fig. 9 ) and calculation expressions as data to be used in the processing program.

[0061] First information 140 (refer to Figure 7 ) represents the resistance value between the second contact portions (24, 26) forming a group, that is, the second resistance value R B The second information 150 (see Fig. 9 ) represents the resistance value between the first contact parts (22, 26) in a group, that is, the first resistance value R A Information on the relationship with the temperature t of the joint 18.

[0062] The calculation formula is based on the first resistance value R A And the first resistance value R is measured A The reference resistance value R is calculated by calculating the temperature t of the junction 18 at A0 By using this calculation formula, the resistance temperature coefficient α of the bonding portion 18 can be calculated. A and the reference temperature t0 to calculate the reference resistance value R A0 .

[0063] The input unit 112 sends data input by the user to the processing unit 100. The input unit 112 functions as an input interface for receiving input operations by the user. The input unit 112 is composed of, for example, a plurality of operation buttons and numeric buttons, or is composed of a touch panel.

[0064] The display unit 114 displays data from the processing unit 100. The display unit 114 displays, for example, measurement results, etc. As a device constituting the display unit 114, a display panel such as a light emitting diode or an LCD (Liquid Crystal Display) can be cited. The display unit 114 of the first embodiment is constituted by, for example, a liquid crystal panel.

[0065] The notification unit 116 makes notifications according to the data from the processing unit 100. The notification unit 116 can notify the user of guidance or warning sounds by sound. As a device for making notifications by sound, a piezoelectric buzzer or a speaker can be cited. The notification unit 116 of the first embodiment is composed of a speaker, for example.

[0066] The clock unit 118 shows the current year, month, day and time, and measures the time. The clock unit 118 outputs the current year, month, day and time to the processing unit 100. For example, when the resistance value is measured by the measuring unit 50, the year, month, day and time shown by the clock unit 118 can be stored in the storage unit 110 in association with each measured value as the time when each measured value is measured.

[0067] The communication unit 120 can transmit and receive data between the processing unit 100 and an external device. For example, the communication unit 120 can output measurement results to the external device. The communication unit 120 constitutes an interface for transmitting and receiving data. The communication unit 120 is composed of hardware that communicates using USB (Universal Serial Bus), Bluetooth (registered trademark), wireless LAN (Local Area Network), etc.

[0068] The processing unit 100 is composed of, for example, a processor. An example of the processor is a central processing unit (CPU). The processing unit 100 reads a processing program stored in the storage unit 110 and operates according to the read processing program. Thus, the processing unit 100 controls each unit of the resistance measuring device 10 to implement the resistance measuring method.

[0069] Furthermore, the processing unit 100 may display the measurement result and the like on the display unit 114 , notify the measurement result through the notification unit 116 , or transmit the measurement result to an external device via the communication unit 120 .

[0070] (Function Block)

[0071] Figure 3 2 is a functional block diagram showing an example of the functional configuration of the resistance measuring device 10 .

[0072] like Figure 3 As shown, the resistance measuring device 10 includes a measurement control unit 130, a temperature acquisition unit 132, and a calculation unit 134. The processing unit 100 executes a software program read from the storage unit 110 as a processing program, thereby realizing the functions of the units 130, 132, and 134 in the resistance measuring device 10.

[0073] (Measurement control unit)

[0074] The measurement control unit 130 controls the switching unit 60 to the first connection state, and measures the first resistance value R between the first contact parts (22, 26) of the set through the measurement unit 50. A In addition, the measurement control unit 130 controls the switching unit 60 to the second connection state, and measures the second resistance value R between the second contact parts (24, 26) in the set through the measurement unit 50. B .

[0075] Thus, the measurement control unit 130 forms a first resistance value R between the first contact parts (22, 26) formed in a set by the measurement unit 50. A and measuring the second resistance value R between the second contact parts (24, 26) of the group by the measuring unit 50. B status.

[0076] It should be noted that, in the first embodiment, the measurement control unit 130 controls the switching unit 60 to form a state where the first resistance value R is measured by the measuring unit 50. A The state and the second resistance value R measured by the measuring unit 50 B The measurement control unit 130 is not limited to this configuration. The measurement control unit 130 may also be configured to form a measurement of the first resistance value R without using the switching unit 60. A state and determination of the second resistance value R B In this case, the first resistance value R is measured. A state and determination of the second resistance value R B The states can be formed simultaneously or separately.

[0077] In addition, the measurement control unit 130 alternately switches the connection state of the switching unit 60, and when measuring the first resistance value R A The second resistance value R is measured before and after B .

[0078] Specifically, the processing unit 100 controls the signal output to the switching unit 60 to connect the switches 62, 64, 66, 68 to the first contacts 62a, 64a, 66a, 68a. Thus, the processing unit 100 sets the switching unit 60 to the first connection state, and connects the first contact portion 22 and the common contact portion 26 constituting the first contact portion (22, 26) as a set to the measuring unit 50.

[0079] When the switch unit 60 is set to the first connection state, the processing unit 100 inputs the voltage value measured by the voltage measuring unit 54 of the measuring unit 50, and calculates the resistance value between the first contact portion 22 and the common contact portion 26 based on the input voltage value and the current value of the current from the supply source 52. The processing unit 100 obtains the calculated resistance value as the first resistance value R A .

[0080] Furthermore, the processing unit 100 controls the signal output to the switching unit 60 to connect the switches 62, 64, 66, 68 to the second contacts 62b, 64b, 66b, 68b. Thus, the processing unit 100 sets the switching unit 60 to the second connection state, and connects the common contact 26 and the second contact 24 constituting the set of second contact portions (24, 26) to the measuring unit 50.

[0081] When the switching unit 60 is in the second connection state, the voltage value measured by the voltage measuring unit 54 of the measuring unit 50 is input to the processing unit 100. In addition, the processing unit 100 calculates the resistance value between the common contact portion 26 and the second contact portion 24 as the second resistance value R based on the input voltage value and the current value of the current from the supply source 52. B .

[0082] Furthermore, the processing unit 100 switches the switching unit 60 to measure the first resistance value R between the first contact portion 22 and the common contact portion 26. A The second resistance value R between the common contact portion 26 and the second contact portion 24 is measured before and after B That is, the processing unit 100 measures the second resistance value R at different timings. B , and measure the first resistance value R between these timings A .

[0083] (Temperature acquisition unit)

[0084] The temperature acquisition unit 132 determines the second resistance value R based on the measured second resistance value R B and the first information 140 (see Figure 7 ) to obtain the temperature t of the joint 18.

[0085] In addition, the temperature acquisition unit 132 refers to the information stored in the storage unit 110. Based on the information, the temperature acquisition unit 132 determines the first resistance value R A The second resistance value R measured just before B The first resistance value R is measured A The second resistance value R measured immediately after B The first resistance value R is estimated and obtained. A The temperature t of the joint 18 at that time.

[0086] In other words, the temperature acquisition unit 132 refers to the information stored in the storage unit 110. Based on the information, the temperature acquisition unit 132 uses at least the first resistance value R A The second resistance value R measured just before B and in determining the first resistance value R A The second resistance value R measured immediately after B The first resistance value R is estimated and obtained by calculating these two values. A The temperature t of the joint 18 at that time.

[0087] Specifically, the first information 140 (refer to Figure 7 ) represents the resistance value between the second contact portions (24, 26) forming a group, that is, the second resistance value R B The processing unit 100 uses the first information 140 (see FIG. 14 ) stored in the storage unit 110 to obtain information about the relationship between the temperature t of the bonding portion 18 and the bonding portion 18. Figure 7 ) to obtain the second resistance value R B The corresponding temperature t of the joint 18 .

[0088] Referring to the first information 140 (refer to Figure 7 ) to obtain the first resistance value R A When the temperature of the bonding portion 18 is 0.0045 W, the processing unit 100 uses at least the first resistance value R A The second resistance value R measured just before B And measure the first resistance value R A The second resistance value R measured immediately after B The temperature t of the joint 18 is estimated based on these two values.

[0089] As an example, the processing unit 100 obtains the first resistance value R A The second resistance value R measured just before B The first resistance value R is measured A The second resistance value R measured immediately after B Then, the processing unit 100 calculates the average value based on the average value and the first information 140 (refer to Figure 7) to obtain the temperature t of the joint 18.

[0090] (Calculation unit)

[0091] The calculation unit 134 calculates the temperature t of the junction portion 18 based on the acquired temperature t and the measured first resistance value R A To calculate the reference resistance value R A0 This calculation uses, for example, a calculation formula stored in the storage unit 110 (for example, refer to Formula 6 described later).

[0092] In addition, the calculation unit 134 calculates the value of the first resistance R based on the acquired temperature t of the junction portion 18 and the measured first resistance value R A and the calculation formula stored in the storage unit 110 to calculate the reference resistance value R A0 .

[0093] Specifically, the processing unit 100 inputs the measured first resistance value R into the calculation formula stored in the storage unit 110. A And the first resistance value R is measured A The reference resistance value R is calculated by calculating the temperature t of the junction 18 at A0 As the temperature t of the joint portion 18 input to the calculation formula, the temperature t of the joint portion 18 acquired by the temperature acquisition unit 132 can be used.

[0094] (Action description)

[0095] Next, the operation of the resistance measuring device 10 will be described according to the processing procedure executed by the processing unit 100 .

[0096] In the stage before starting the measurement, the resistance measuring device 10 performs a process for obtaining the first information 140 (see Figure 7 ), second information 150 (refer to Fig. 9 ) and calculation expressions. Figures 4 to 9 This preprocessing will be described.

[0097] Figure 4 1 is a flowchart showing an example of the pre-processing operation of the resistance measuring device 10 . Figure 5 Yes means Figure 4 Flowchart of subsequent actions. Figure 6 Yes means Figure 5 Flowchart of subsequent actions. In addition, Figure 7 is the temperature t of the junction 18 and the second resistance value R B relationship line graph. Figure 8 It indicates that the first resistance value R is measured based on A The second resistance value R measured before and after B To obtain the first resistance value R AAn explanatory diagram of the process of the temperature t of the bonding portion 18 at . Fig. 9 is the temperature t of the junction 18 and the first resistance value R A Line graph of the relationship.

[0098] like Figure 4 As shown, when the main routine is executed according to the processing program stored in the storage unit 110 and the pre-processing called from the main routine is executed, the processing unit 100 performs data input processing (step S10).

[0099] In the data input process, the processing unit 100 receives, for example, an input requesting a reference temperature t0 (eg, 20° C.) as an arbitrary temperature and a known resistance temperature coefficient α of the second member 14 . B The input screen for inputting is displayed on the display unit 114. Then, when the user inputs the reference temperature t0 and the resistance temperature coefficient α from the input unit 112, B When the processing unit 100 receives the reference temperature t0 and the resistance temperature coefficient α B Stored in the storage unit 110 .

[0100] Furthermore, the processor 100 displays guidance for preparing for measurement on the display unit 114 (step S12 ).

[0101] Specifically, the processing unit 100 guides the first energized probe 30 to contact the first member 12, and the first measurement probe 32 to contact the first member 12 at a position closer to the joint 18 than the first energized probe 30. In addition, the processing unit 100 guides the common first probe 34 to contact the second member 14, and the common second probe 36 to contact the second member 14 at a position farther from the joint 18 than the common first probe 34. Furthermore, the processing unit 100 guides the second measurement probe 42 to contact the second member 14, and the second energized probe 40 to contact the second member 14 at a position farther from the contact position of the common second probe 36 than the second measurement probe 42.

[0102] The processing unit 100 guides the object 16 to be placed in a room where the room temperature is stabilized at a predetermined temperature t1 for a predetermined time. The predetermined time is set to the time required for the object 16 placed in the room to reach the predetermined temperature t1.

[0103] Then, the processing unit 100 determines whether a predetermined time has passed since the object 16 was placed in the room at the predetermined temperature t1 (step S14). If it is determined that the predetermined time has passed in step S14, the processing unit 100 stores the temperature of the object 16 as the predetermined temperature t1 in the storage unit 110 (step S16).

[0104] Here, the first member 12 and the second member 14 constituting the object 16 are made of a metal with high thermal conductivity such as copper or aluminum. Therefore, the temperature of the object 16, the temperature of the first member 12, the temperature of the second member 14, and the temperature of the joint 18 joining the first member 12 and the second member 14 are set to be substantially the same temperature. In addition, the temperature between the common contact portion 26 and the second contact portion 24 and the temperature between the first contact portion 22 and the common contact portion 26 are also set to be substantially the same temperature as the temperature of the object 16.

[0105] Furthermore, the processing unit 100 controls the signal output to the switching unit 60 to put the switching unit 60 into the second connection state, thereby connecting the common contact portion 26 and the second contact portion 24 to the measuring unit 50 (step S18 ).

[0106] When the switching unit 60 is in the second connection state, the processing unit 100 inputs the voltage value measured by the voltage measuring unit 54 of the measuring unit 50. Then, the processing unit 100 calculates the resistance value between the common contact portion 26 and the second contact portion 24 based on the input voltage value and the current value of the current flowing from the supply source 52 (step S20). The processing unit 100 uses the calculated resistance value as the second resistance value R of the second member 14 when the temperature is the predetermined temperature t1. B1 The data is stored in the storage unit 110 (step S22).

[0107] Then, the processing unit 100 calculates the reference resistance value R of the second member 14 at the reference temperature t0 using a calculation formula for obtaining the temperature coefficient of resistance. B0 (Step S24 ) Here, the temperature coefficient of resistance refers to the change ratio when the resistance value changes with the change of temperature.

[0108] Specifically, the processing unit 100 uses the following (Formula 1) obtained from the formula for calculating the temperature coefficient of resistance to calculate the reference resistance value R of the second member 14 when the temperature of the object 16 is the reference temperature t0. B0 .

[0109] [Formula 1]

[0110]

[0111] R B0 α represents the reference resistance value of the second member 14 at the reference temperature t0. B represents the resistance temperature coefficient of the second member 14. t1 represents a predetermined temperature as the temperature of the object 16. t0 represents the reference temperature input in step S10. B1 The second resistance value of the second member 14 measured at the predetermined temperature t1 is shown.

[0112] like Figure 7 As shown, the processing unit 100 is based on the reference temperature t0 and the resistance temperature coefficient α B , specified temperature t1, the second resistance value R at the specified temperature t1 B1 And the reference resistance value R B0 , generating the first information 140 as information and storing it in the storage unit 110 (step S26).

[0113] In this Figure 7 In, R B represents the resistance value between the common contact portion 26 and the second contact portion 24. t represents the temperature between the common contact portion 26 and the second contact portion 24.

[0114] It should be noted that the first information 140 stored in the storage unit 110 may also include information indicating the reference temperature t0, the resistance temperature coefficient α B , specified temperature t1, the second resistance value R at the specified temperature t1 B1 And the reference resistance value R B0 It consists of a diagram, data set or data table showing the relationship between the two.

[0115] Next, the processing unit 100 alternately measures the first resistance value R between the first contact portion 22 and the common contact portion 26 in the object 16 whose temperature changes. A and a second resistance value R between the common contact portion 26 and the second contact portion 24 B The data is stored in the storage unit 110 .

[0116] As the first resistance value R is measured while changing the temperature of the object 16 A and the second resistance R B The method may be, for example, measuring the first resistance value R during the cooling period after welding the joint 18 of the first member 12 and the second member 14. A and the second resistance R B The cooling period includes a period from immediately after the first member 12 and the second member 14 are welded to when the object 16 drops to a specific temperature.

[0117] like Figure 5 As shown, the processing unit 100 inputs the value "5" into the storage area n secured in the storage unit 110 (step S30). Then, the processing unit 100 controls the signal output to the switching unit 60 to put the switching unit 60 into the second connection state, connecting the common contact portion 26 and the second contact portion 24 to the measuring unit 50 (step S32).

[0118] In the second connection state, the processing unit 100 inputs the voltage value measured by the voltage measuring unit 54 of the measuring unit 50. In addition, the processing unit 100 calculates the resistance value between the common contact portion 26 and the second contact portion 24 based on the voltage value and the current value of the current flowing from the supply source 52 as the second resistance value R B(n)－1 (Step S34).

[0119] Here, in R B(n)－1 The value stored in the storage area n of the storage unit 110 is substituted into “(n)”.

[0120] Furthermore, the processing unit 100 controls the signal output to the switching unit 60 to place the switching unit 60 in the first connection state, thereby connecting the first contact portion 22 and the common contact portion 26 to the measuring unit 50 (step S36 ).

[0121] In the first connection state, the processing unit 100 inputs the voltage value measured by the voltage measuring unit 54 of the measuring unit 50. In addition, the processing unit 100 calculates the resistance value between the first contact portion 22 and the common contact portion 26 based on the voltage value and the current value of the current flowing from the supply source 52 as the first resistance value R A(n) (Step S38).

[0122] Here, in R A(n) The value stored in the storage area n of the storage unit 110 is substituted into “(n)”.

[0123] Then, the processing unit 100 controls the signal output to the switching unit 60 to place the switching unit 60 in the second connection state, thereby connecting the common contact portion 26 and the second contact portion 24 to the measuring unit 50 (step S40 ).

[0124] In the second connection state, the processing unit 100 inputs the voltage value measured by the voltage measuring unit 54 of the measuring unit 50. In addition, the processing unit 100 calculates the resistance value between the common contact portion 26 and the second contact portion 24 based on the voltage value and the current value of the current flowing from the supply source 52 as the second resistance value R B(n)－2 (Step S42).

[0125] Here, in R B(n)－2 The value stored in the storage area n of the storage unit 110 is substituted into “(n)”.

[0126] Then, the processing unit 100 decrements the value stored in the storage area n by "1" (step S44), and determines whether the predetermined number of measurements have been completed based on whether the value stored in the storage area n is "2" (step S46).

[0127] In step S46 , when the numerical value stored in the storage area n is not “2”, the processing unit 100 branches to step S32 and executes each step until the number of measurements (for example, four times) is completed.

[0128] Thus, the processing unit 100 obtains the second resistance value R B5－1 , the first resistance value R A5 , the second resistance value R B5－2 , the second resistance value R B4－1 , the first resistance value R A4 , the second resistance value R B4－2 ...and stores it in the storage unit 110.

[0129] When it is determined in step S46 that the value of the storage area n is "2", the processing unit 100 measures the predetermined first resistance value R A The second resistance value R measured just before B The first resistance value R is determined in A The second resistance value R measured immediately after B The relationship between the first resistance value R A The second resistance value R B .

[0130] Thus, the processing unit 100 uses at least the first resistance value R A The second resistance value R measured just before B and the first resistance value R A The second resistance value R measured immediately after B These two values ​​are used to estimate the first resistance value R A The second resistance value R B .

[0131] like Figure 6 As shown, the processing unit 100 calculates the first resistance value R A The second resistance value R measured before and after B The calculated average value is estimated as the measured first resistance value R A The second resistance value R B (Step S50).

[0132] Specifically, the processing unit 100 sets the first resistance value R A5 The second resistance value R measured before and after B5－1 and the second resistance value R B5－2 The added value is divided by 2 to calculate the average value, and the calculated average value is estimated as the measured first resistance value R A5 The second resistance value R B5The processing unit 100 calculates the first resistance value R A2 ~R A5 The second resistance value R B2 ~R B5 presumption.

[0133] Then, the processing unit 100 converts the estimated second resistance values ​​R B2 ~R B5 The temperatures t2 to t5 of the junction portion 18 are set to the first resistance value R corresponding to the measured value. A2 ~R A5 The temperature of the bonding portion 18 at that time is t2 to t5 (step S52).

[0134] like Figure 8 As shown in FIG. 1 , the temperature t of the object 16 decreases with the passage of time. Therefore, the second resistance value R B5－1 The temperature t of the object 16 at the time of the measurement and the first resistance value R A5 The temperature t of the object 16 at that time may be different.

[0135] Therefore, the processing unit 100 calculates the first resistance value R A5 The second resistance value R measured before and after B5－1 With the second resistor value R B5－2 In addition, the processing unit 100 estimates the calculated average value as the measured first resistance value R A5 The second resistance value R B5 , obtain the measured first resistance value R A5 The temperature t5 of the joint 18 at that time.

[0136] It should be noted that, in the first embodiment, the second resistance value R B , the first resistance value R A , the second resistance value R B The case where measurements performed in the order of are set as one cycle and the measurement cycle is repeated four times has been described, but the first embodiment is not limited to this.

[0137] For example, the second resistance value R may be alternately set multiple times. B Determination of the first resistance value R A In this case, the second resistance value R can be reduced B The number of measurements.

[0138] In addition, the first resistance value R is measured. A The second resistance value R B It can also be based on the second resistance value R BThe first resistance value R is measured A The time from the first resistance value R to the measurement A The second resistance value R after the measurement B It can be calculated by comparing the time from the measurement to the end.

[0139] Then, the processing unit 100 determines the first resistance value R A The second information 150 is obtained by comparing the obtained temperature t of the joint 18 (see Fig. 9 )(Step S54).

[0140] Specifically, the processing unit 100 obtains the measured first resistance value R A The second information 150 is generated by the correspondence relationship with the estimated temperature t of the joint portion 18 (see Fig. 9 ), and stores the second information 150 in the storage unit 110 (step S54).

[0141] Fig. 9 The first resistance value R A An example of the second information 150 showing the correspondence relationship with the estimated temperature t of the joint portion 18 .

[0142] Then, the processing unit 100 obtains the resistance temperature coefficient between the common contact portion 26 and the second contact portion 24 as the resistance temperature coefficient α of the joint portion 18 that is dominant between the common contact portion 26 and the second contact portion 24 based on the second information 150. A (Step S56).

[0143] Thus, the function of the processing unit 100 realizes a coefficient calculation unit based on the plurality of first resistance values ​​R obtained by alternately switching the connection state of the switching unit 60. A and a plurality of second resistance values ​​R B The resistance temperature coefficient α of the junction 18 is calculated by using the data represented in time series. A .

[0144] Specifically, the first resistance value R A The second information 150 of the correspondence relationship with the temperature t of the joint portion 18 can be expressed by the following (Formula 2) representing a straight line. It should be noted that the straight line represented by (Formula 2) can be obtained by using, for example, the least square method.

[0145] R A =C1×t+C2……(Formula 2)

[0146] R A C1 represents the slope of the straight line representing the second information 150 (refer to Fig. 9 ). C2 represents the intercept of the straight line representing the second information 150 (refer to Fig. 9 ).

[0147] In addition, the linear expression obtained from the calculation formula for obtaining the temperature coefficient of resistance is shown in the following (Formula 3).

[0148] R A =R A0 ×{1+α A ×(t-t0)}……(Formula 3)

[0149] R A Represents the first resistance value. R A0 α represents the reference resistance value of the junction 18 that is dominant between the common contact portion 26 and the first contact portion 22 at a reference temperature t0 (for example, 20° C.). A represents the resistance temperature coefficient of the joint portion 18 that is dominant between the common contact portion 26 and the first contact portion 22. t represents the temperature of the joint portion 18 between the common contact portion 26 and the first contact portion 22. t0 represents the reference temperature of the joint portion 18 between the common contact portion 26 and the first contact portion 22.

[0150] Then, by solving the simultaneous equations of the two equations (Equation 2) and (Equation 3), the following (Equation 4) is obtained.

[0151] [Formula 2]

[0152]

[0153] The calculation process is shown below.

[0154] R A =R A0 ×{1+α A ×(t-t0)} is transformed to obtain the following (Formula 5).

[0155] R A =R A0 ×α A ×t+R A0 ×(1-α A ×t0)……(Formula 5)

[0156] According to the formula (5) and (2), "R A =C1×t+C2”, C1 represents “R A 0×α A ”, so find “R A0 =C1 / α A ” formula.

[0157] In addition, C2 indicates "RA0 ×(1-α A ×t0)”, so “R A0 =C1 / α A Substitute into the equation for C2 and find "C2=C1 / α A ×(1-α A ×t0)=C1 / α A -C1×t0".

[0158] Transforming this formula, we get "C2+C1×t0=C1 / α A ", by further transforming the formula, we get the above (Formula 4).

[0159] Here, the temperature t is based on the second resistance value R between the second contact portion 24 and the common contact portion 26 B Therefore, the internal state of the second member 14 is reflected in the temperature t.

[0160] Then, the processing unit 100 determines the resistance temperature coefficient α of the bonding portion 18 based on the resistance temperature coefficient α of the bonding portion 18. A and the reference temperature t0 to find the reference resistance value R A0 The obtained calculation formula is stored in the storage unit 110 (step S58), the preprocessing is ended and the main routine is returned.

[0161] Specifically, the processing unit 100 uses a formula for calculating the temperature coefficient of resistance to calculate the resistance temperature coefficient based on the measured first resistance value (R A6 ) and the temperature (t6) of the junction 18 to find the reference resistance value R A0 The calculation formula is stored in the storage unit 110. The calculation formula is shown in the following (Formula 6).

[0162] [Formula 3]

[0163]

[0164] R A0 It represents the reference resistance value when the junction 18 is at the reference temperature t0. A6 t6 indicates the first resistance value R A6 The temperature of the joint 18 at α A t0 represents the resistance temperature coefficient of the junction 18 which is dominant between the common contact portion 26 and the first contact portion 22. t1 represents the reference temperature of the junction 18 between the common contact portion 26 and the first contact portion 22.

[0165] (Measurement Process)

[0166] Next, the reference resistance value R of the joint 18 in the object 16 to be measured is A0The measurement process of ' is described below.

[0167] Fig.10 1 is a flowchart showing an example of the operation of the measurement process of the resistance measurement device 10 . Fig.11 The second resistance value R represents the change from high temperature to low temperature. B Illustration of changes over time. Fig.12 is a function of the temperature t of the junction 18 and the first resistance value R A The reference resistance value R is obtained by A0 ' is an illustration of the situation.

[0168] That is, when the measurement process is called from the main routine, the processing unit 100 controls the signal output to the switching unit 60 to put the switching unit 60 into the second connection state, and connects the common contact portion 26 and the second contact portion 24 to the measurement unit 50 (step SB10).

[0169] In the second connection state, the processing unit 100 inputs the voltage value measured by the voltage measuring unit 54 of the measuring unit 50. In addition, the processing unit 100 sets the resistance value between the common contact portion 26 and the second contact portion 24 calculated based on the voltage value and the current value of the current flowing from the supply source 52 as the second resistance value R B6－1 (Step SB12).

[0170] Furthermore, the processing unit 100 controls the signal output to the switching unit 60 to place the switching unit 60 in the first connection state, thereby connecting the first contact portion 22 and the common contact portion 26 to the measuring unit 50 (step SB14 ).

[0171] In the first connection state, the processing unit 100 inputs the voltage value measured by the voltage measuring unit 54 of the measuring unit 50. In addition, the processing unit 100 sets the resistance value between the first contact portion 22 and the common contact portion 26 calculated based on the voltage value and the current value of the current flowing from the supply source 52 as the first resistance value R A6 '(Step SB16).

[0172] Furthermore, the processing unit 100 controls the signal output to the switching unit 60 to put the switching unit 60 into the second connection state, thereby connecting the common contact portion 26 and the second contact portion 24 to the measuring unit 50 (step SB18 ).

[0173] In the second connection state, the processing unit 100 inputs the voltage value measured by the voltage measuring unit 54 of the measuring unit 50. In addition, the processing unit 100 sets the resistance value between the common contact portion 26 and the second contact portion 24 calculated based on the voltage value and the current value of the current flowing from the supply source 52 as the second resistance value R B6－2 (Step SB20).

[0174] In addition, the processing unit 100 measures the first resistance value R A6 The second resistance value R measured just before B6－1 The first resistance value R is measured A6 The second resistance value R measured immediately after B6－2 The first resistance value R is estimated and measured. A6 The second resistance value R B6 (Step SB22).

[0175] Thus, the processing unit 100 uses the first resistance value R A6 The second resistance value R measured just before B6－1 and in determining the first resistance value R A6 The second resistance value R measured immediately after B6－2 The first resistance value R is estimated from these two values. A6 The second resistance value R B6 .

[0176] Specifically, the processing unit 100 sets the second resistance value R B6－1 and the second resistance value R B6－2 The value obtained by adding and dividing the added value by "2" is set as the second resistance value R B6 . Thus, the first resistance value R is calculated. A6 The second resistance value R measured before and after B6－1 With the second resistor value R B6－2 The calculated average value is estimated as the first resistance value R A6 The second resistance value R B6 .

[0177] Next, the processing unit 100 uses the first information 140 (see Figure 8 ), based on the estimated second resistance value R B6 To obtain the temperature t6 of the joint 18 (step SB24). Figure 8 The second resistance value R is not shown in the figure. B6 and the temperature t6 of the joint 18 .

[0178] like Fig.11 As shown in FIG. 1 , when the object 16 changes from a high temperature to a low temperature, the temperature change of the object 16 becomes larger in the high temperature region H. Therefore, if the second resistance value R for measuring the temperature t of the junction 18 is B The first resistance value R for checking the state of the joint 18 is measured A The time difference between the measurements is generated, and the second resistance value R is measured. BThe temperature t at which the first resistance value R is measured A There may be a large difference between the temperature t at the time.

[0179] Therefore, the processing unit 100 calculates the first resistance value R A6 The second resistance value R measured before and after B6－1 With the second resistor value R B6－2 Then, the processing unit 100 uses the calculated average value as the measured first resistance value R A6 The second resistance value R B6 The temperature t of the joint 18 can be acquired, thereby achieving high-precision measurement.

[0180] Next, the processing unit 100 calculates the temperature t6 of the junction portion 18 and the measured first resistance value R A6 'Substitute into the calculation formula (refer to Formula 6) stored in the storage unit 110, thereby calculating the reference resistance value R of the junction 18 at the reference temperature t0 A0 'To obtain the measurement result (step SB26).

[0181] like Fig.12 As shown, the first resistance value R A6 ' and the resistance temperature coefficient α of the junction 18 A The reference resistance value R of the junction 18 at the reference temperature t0 is obtained. A0 '.

[0182] Then, the processing unit 100 converts the calculated reference resistance value R A0 The measurement result is outputted by displaying it on the display unit 114, notifying it from the notification unit 116, or transmitting it to an external device via the communication unit 120 (step SB28), and the program returns to the main routine.

[0183] (Function and Effect)

[0184] Next, the effects obtained by the first embodiment will be described.

[0185] The resistance measuring device 10 of the first embodiment measures a reference resistance value R of a joint portion 18 at a preset reference temperature t0 in an object 16 formed by joining a first member 12 and a second member 14 to each other. A0The resistance measuring device 10 comprises: a connection structure 20, comprising a group of first contact parts (22, 26) respectively contacting the first member 12 and the second member 14, and a group of second contact parts (24, 26) contacting different parts of the second member 14. The resistance measuring device 10 comprises: a measuring unit 50 for measuring the resistance value between the group of first contact parts (22, 26) and the resistance value between the group of second contact parts (24, 26). The resistance measuring device 10 comprises: a storage unit 110 for storing information (140) indicating the relationship between the resistance value between the group of second contact parts (24, 26) and the temperature t of the joint 18.

[0186] Furthermore, the resistance measuring device 10 includes a measurement control unit 130 for measuring a first resistance value R between the first contact portions (22, 26) forming a pair through the measuring unit 50. A and a second resistance value R between the second contact portions (24, 26) of the group B The resistance measuring device 10 includes a temperature acquiring unit 132 that calculates the temperature of the second resistance value R based on the measured second resistance value R. B The resistance measuring device 10 is provided with a calculation unit 134 for calculating the temperature t of the joint 18 based on the obtained temperature t of the joint 18 and the measured first resistance value R A To calculate the reference resistance value R A0 .

[0187] The resistance measuring method of the first embodiment measures a reference resistance value R of a joint portion 18 at a preset reference temperature t0 in an object 16 formed by joining the first member 12 and the second member 14 to each other. A0 The resistance measuring method comprises a group of first contact parts (22, 26) respectively contacting a first member 12 and a second member 14, and a group of second contact parts (24, 26) contacting different parts of the second member (14), and performs: a process of measuring the resistance value between the group of first contact parts (22, 26) and the resistance value between the group of second contact parts (24, 26) by a measuring part 50; a process of selectively switching between a first connection state in which the group of first contact parts (22, 26) are connected to the measuring part 50 and a second connection state in which the group of second contact parts (24, 26) are connected to the measuring part 50; and a process of storing information (140) indicating the relationship between the resistance value between the group of second contact parts (24, 26) and the temperature t of the joint 18.

[0188] Furthermore, the resistance measuring method comprises measuring a first resistance value R between the first contact parts (22, 26) forming a group. A and measuring a second resistance value R between the second contact portions (24, 26) in a groupB The resistance measurement method includes a measurement control process (steps SB10 to SB20) based on the measured second resistance value R B The resistance measuring method includes a temperature acquisition process (steps SB22 to SB24) for acquiring the temperature t of the joint 18 based on the acquired temperature t of the joint 18 and the measured first resistance value R A To calculate the reference resistance value R A0 Calculation process (step SB26).

[0189] In the resistance measuring device 10 and the resistance measuring method of these structures, the first resistance value R between the first contact parts (22, 26) in contact with the first member 12 and the second member 14 is measured by the measuring unit 52. A and a second resistance value R between a set of second contact portions (24, 26) contacting different portions of the second member 14. B In addition, the second resistance value R between the second contact parts (24, 26) is represented B The information ( 140 ) on the relationship between the temperature t of the joint 18 of the first member 12 and the second member 14 is stored in the storage unit 110 , for example.

[0190] Then, based on the second resistance value R measured by the measuring unit 50 B The temperature of the joint portion 18 is acquired based on the acquired temperature of the joint portion 18 and the measured first resistance value R A To calculate the reference resistance value R A0 .

[0191] Thus, based on the second resistance value R between the second contact portions (24, 26) B The temperature of the joint 18 is acquired by using information (140) on the relationship between the current flowing through the second member 14 and the temperature t of the joint 18. Here, the second resistance value R between the second contact parts (24, 26) for acquiring the temperature of the joint 18 is obtained based on the current flowing through the inside of the second member 14. B Therefore, the temperature of the bonding portion 18 can be measured with high accuracy, compared to the case where the temperature is measured by a radiation thermometer that can only measure the surface temperature.

[0192] Here, in the first embodiment, the first member 12 and the second member 14 constituting the object 16 are formed of metal with low emissivity. Thus, when the temperature of the object 16 formed of metal is measured by a radiation thermometer, it is difficult to measure the temperature accurately. However, in the first embodiment, the temperature of the joint 18 is based on the second resistance value R between the second contact portions (24, 26). BThe information (140) on the relationship between the temperature t of the bonding portion 18 and the bonding portion 18 can be obtained. Therefore, the temperature of the bonding portion 18 can be measured with higher accuracy than when the temperature is measured by a radiation thermometer.

[0193] And, the reference resistance value R A0 Based on the acquired temperature of the joint portion 18 and the measured first resistance value R between the first contact portions (22, 26) A Therefore, the first resistance value R measured based on the surface temperature of the object 16 acquired by the radiation thermometer is calculated. A The resistance measuring device 10 and the resistance measuring method can improve the temperature correction accuracy compared to the case where temperature correction is performed.

[0194] In addition, the resistance measuring device 10 of the first embodiment further includes: a switching unit 60 that selectively switches between a first connection state in which the first contact portions (22, 26) formed in a group are connected to the measuring unit 50 and a second connection state in which the second contact portions (24, 26) formed in a group are connected to the measuring unit 50. The measurement control unit 130 controls the switching unit 60 to the first connection state to form a first resistance value R measured by the measuring unit 50. A The switching unit 60 is controlled to be in the second connection state to form a second resistance value R measured by the measuring unit 50. B status.

[0195] In this structure, the resistance measuring device 10 includes: a switching section 60 that selectively switches between a first connection state in which a set of first contact sections (22, 26) are connected to the measuring section 50 and a second connection state in which a set of second contact sections (24, 26) are connected to the measuring section 50.

[0196] Furthermore, a first resistance value R between the first contact portions (22, 26) forming a group is to be measured. A When the resistance measuring device 10 controls the switching unit 60 to the first connection state, the current from the measuring unit 50 flows between the first contact parts (22, 26) of the group, thereby measuring the first resistance value R A In addition, when measuring the second resistance value R between the second contact parts (24, 26) in a group, B When the resistance measuring device 10 controls the switching unit 60 to the second connection state, the current from the measuring unit 50 flows between the second contact parts (24, 26) of the group, thereby measuring the second resistance value R B .

[0197] Thus, the resistance measuring device 10 is used to measure the first resistance value R A The current and the second resistance value R B The current will not flow to the object 16 at the same time.

[0198] Therefore, the first resistance value R is determined by A The current and the second resistance value R B Compared with the structure in which the current flows to the object 16 at the same time, it is possible to avoid the need to measure the first resistance value R A The current used to determine the second resistance value R B Thus, the resistance measuring device 10 can suppress the influence caused by the current interference.

[0199] Furthermore, since only one measuring unit 50 is required to measure the resistance value, it is possible to achieve a more compact and lower-cost device compared to a case where a plurality of measuring units 50 are required.

[0200] Then, the first resistance value R is measured by a different measuring unit 50. A and the second resistance value R B Compared with the case where the measurement error that may occur in each measuring unit is prevented from being superimposed, the measurement accuracy can be improved.

[0201] In addition, in the structure including a plurality of measuring parts 50, the first resistance value R A and the second resistance value R B Compared with the situation where it is necessary to adjust the measurement timing of each measuring unit, the control can be simplified.

[0202] In the resistance measuring device 10 of the first embodiment, one first contact portion (26) in contact with the second member 14 among the set of first contact portions (22, 26) and one second contact portion (26) among the set of second contact portions (24, 26) are shared.

[0203] In this structure, one (26) of the first contact parts (22, 26) in the group that contacts the second member 14 and one (26) of the second contact parts (24, 26) in the group are shared. Therefore, the number of contact parts that come into contact with the object 16 can be reduced, thereby achieving cost reduction. In addition, since the number of contact points with the object 16 is reduced, measurement can be performed even in a narrow place.

[0204] In the resistance measuring device 10 of the first embodiment, the storage unit 110 stores the first resistance value R A And the first resistance value R is measured A The reference resistance value R is calculated by calculating the temperature of the junction 18 at A0 The calculation unit 134 calculates the value of the first resistance R based on the acquired temperature t of the junction 18 and the measured first resistance value R. A and the calculation formula stored in the storage unit 110 to calculate the reference resistance value R A0 .

[0205] In this configuration, by using the calculation formula stored in the storage unit 110, the first resistance value R A And the first resistance value R is measured A The reference resistance value R is calculated by the temperature of the junction 18 at A0 .

[0206] Therefore, the reference resistance value R is used to find A0 The reference resistance value R can be obtained by using a data sheet or graph A0 Compared with the case of FIG. 1 , the amount of data stored in the storage unit 110 can be reduced.

[0207] In the resistance measuring device 10 of the first embodiment, the measurement control unit 130 alternately switches the connection state of the switching unit 60 to measure the first resistance value R A The second resistance value R is measured before and after B The temperature acquisition unit 132 refers to the information (140) stored in the storage unit 110, based on the first resistance value R A The second resistance value R measured just before B The first resistance value R is measured A The second resistance value R measured immediately after B The first resistance value R is estimated and obtained by the relationship A The temperature t of the joint 18 at that time.

[0208] In this structure, when the temperature of the object 16 changes from a high temperature to a low temperature, the temperature change of the object 16 becomes large in the high temperature region H. Therefore, if the second resistance value R for measuring the temperature t of the junction 18 is B The first resistance value R for checking the state of the joint 18 is measured A The time difference between the measurements is generated, and the second resistance value R is measured. B The temperature t at which the first resistance value R is measured A There may be a large difference between the temperature t at the time.

[0209] Therefore, by based on the first resistance value R A6 The second resistance value R measured before and after B6－1 With the second resistor value R B6－2 The first resistance value R is estimated and measured by the relationship A6 The temperature t of the junction 18 at the time of the measurement can be obtained with high accuracy. A0 The measurement accuracy.

[0210] In the resistance measuring device 10 of the first embodiment, when measuring the first resistance value RA The second resistance value R measured just before B The first resistance value R is measured A The second resistance value R measured immediately after B The relationship is: When measuring the first resistance value R A The second resistance value R measured before and after B When the second resistance value R is obtained B When the average value is obtained, the temperature acquisition unit 132 refers to the information (140) stored in the storage unit 110, and obtains the temperature t of the junction 18 corresponding to the average value as the first resistance value R A The temperature t of the joint 18 at that time.

[0211] In this structure, the first resistance value R can be measured based on A The second resistance value R measured just before B The first resistance value R is measured A The second resistance value R measured immediately after B The first resistance value R is obtained by taking the average value of A Therefore, the calculation can be simplified and the reference resistance value R can be increased. A0 The measurement accuracy.

[0212] The resistance measuring device 10 of the first embodiment further includes a coefficient calculating unit that calculates the coefficient based on the acquired plurality of first resistance values ​​R A and a plurality of second resistance values ​​R B The resistance temperature coefficient α of the junction 18 is calculated by using the data represented in time series. A It should be noted that, as described above, the coefficient calculation unit is realized by the processing unit 100 by causing the processing unit 100 to operate according to the processing program stored in the storage unit 110 .

[0213] In this configuration, the resistance measuring device 10 obtains the first resistance value R based on, for example, alternately switching the connection state of the switching unit 60. A and the second resistance value R B The resistance temperature coefficient α of the junction 18 is calculated by using the time series data A Therefore, the first resistance value R obtained by the different measuring unit 50 is A and the second resistance value R B Compared with the case where the resistance temperature coefficient of the junction 18 is calculated, the resistance temperature coefficient α can be increased. A The calculation accuracy of .

[0214] The resistance measuring method of the first embodiment includes obtaining a second resistance value R BThe first information acquisition process (steps S14 to S26) of the first information 140 on the relationship between the temperature t of the bonding portion 18 and the resistance measurement method includes measuring the second resistance value R by the measurement unit 50 in the second connection state. B The resistance measuring method includes switching to the first connection state after the first measurement process, and measuring the first resistance value R by the measuring unit 50. A The resistance measuring method includes switching to the second connection state after the preliminary second measurement process, and measuring the second resistance value R by the measuring unit 50. B The resistance measuring method comprises at least using the second resistance value R measured in the first measurement process. B and the second resistance value R measured in the third measurement process in advance B These two values ​​will be used to determine the first resistance value R in the second measurement process. A The resistance value between the second contact parts (24, 26) when B pre-estimation process (step S50).

[0215] In this structure, when the temperature of the object 16 changes from a high temperature to a low temperature, the temperature change of the object 16 becomes large in the high temperature region H. Therefore, if the second resistance value R for measuring the temperature t of the junction 18 is B The first resistance value R for checking the state of the joint 18 is measured A The time difference between the measurements is generated, and the second resistance value R is measured. B The temperature t at which the first resistance value R is measured A There may be a large difference between the temperature t at the time.

[0216] Therefore, the resistance measurement method uses at least the first resistance value R A The second resistance value R measured before and after B The first resistance value R is estimated by using the two values A The resistance value between the second contact parts (24, 26) when B Thus, the second resistance value R can be used B To obtain the first resistance value R A The temperature of the bonding portion 18 at the time of the measurement is measured, so the temperature of the bonding portion 18 can be acquired with high accuracy.

[0217] The resistance measuring method of the first embodiment includes a method of measuring the resistance based on the second resistance value R estimated in a pre-estimation process. Band the first information 140 to obtain the first resistance value R measured in the second measurement process in advance A The resistance measuring method includes a step of obtaining the temperature t of the bonding portion 18 at the time of the first resistance value R A The second information 150 about the relationship between the temperature t of the junction portion 18 and the resistance temperature coefficient α of the junction portion 18 is calculated. A The resistance measuring method includes storing the resistance temperature coefficient α of the junction 18 obtained in the resistance temperature coefficient calculation process. A and the reference temperature t0 to calculate the reference resistance value R A0 The calculation formula storage process of the operation formula (step S58).

[0218] In this structure, the second resistance value R estimated in the pre-estimation process can be used. B and the first information 140 to obtain the first resistance value R measured in the second measurement process in advance A The temperature t of the bonding portion 18 at that time is determined, so the temperature of the bonding portion 18 can be acquired with high accuracy.

[0219] Furthermore, the resistance measurement method is based on the first resistance value R A The second information 150 about the relationship between the temperature t of the junction portion 18 and the resistance temperature coefficient α of the junction portion 18 is calculated. A In addition, the resistance determination method will be based on the resistance temperature coefficient α A and the reference temperature t0 to calculate the reference resistance value R A0 The calculation expression of is stored in, for example, the storage unit 110.

[0220] Therefore, the first resistance value R can be calculated based on the measured first resistance value R by using, for example, the calculation formula stored in the storage unit 110. A And the first resistance value R is measured A The reference resistance value R is calculated by calculating the temperature t of the junction 18 at A0 Therefore, the reference resistance value R A0 The reference resistance value R can be obtained by using a data sheet or graph A0 Compared with the case of FIG. 1 , the amount of data stored in the storage unit 110 can be reduced.

[0221] In the resistance measuring method of the first embodiment, the first information acquisition process includes setting the object 16 to a second connection state at a predetermined temperature t1, and measuring the second resistance value R by the measuring unit 50. B The resistance measuring method includes a predetermined temperature measuring process (steps S14 to S12). The resistance measuring method includes a second resistance value R measured in the predetermined temperature measuring process. B, the predetermined temperature t1, the resistance temperature coefficient α of the second member 14 A The information generating process (steps S24 to S26) of generating the first information 140 by using the reference temperature t0.

[0222] In this configuration, the first information 140 is based on, for example, the second resistance value R measured by setting the switch unit 60 to the second connection state. B Therefore, the first information 140 can be generated under the same measurement environment as the second information 150.

[0223] Therefore, compared with the case where the first information 140 and the second information 150 are generated based on measurement values ​​measured under different measurement environments, the influence on the first information 140 and the second information 150 that may be generated due to the measurement error can be suppressed.

[0224] In the resistance measuring method of the first embodiment, the preliminary first to third measurement processes are acquired while the joint 18 formed by the first member 12 and the second member 14 being joined to each other is cooled.

[0225] In this structure, for example, when the first member 12 and the second member 14 are joined by welding, a temperature change occurs when the temperature of the object 16, which has become high temperature due to the heat of welding, drops. Therefore, by utilizing the cooling process of the object 16, which has become high temperature due to the heat of welding, the first resistance value R can be measured while changing the temperature of the object 16. A and the second resistance value R B .

[0226] Thus, the time immediately after welding can be effectively utilized. In addition, the trouble of heating or cooling the object 16 can be omitted.

[0227] (Second Embodiment)

[0228] Next, a second embodiment will be described.

[0229] Fig.13 Schematic diagram showing a resistance measuring device 200 according to a second embodiment. In the resistance measuring device 200 according to the second embodiment, the same or equivalent parts as those in the first embodiment are denoted by the same reference numerals and their description is omitted, and only different parts are described.

[0230] like Fig.13 As shown, the resistance measuring device 200 is different from the first embodiment in that the measuring section 50 is composed of a first measuring section 50a and a second measuring section 50b.

[0231] The measuring unit 50 of the resistance measuring device 200 includes a first measuring unit 50a for measuring the resistance value between the first contact parts (22, 26) and a second measuring unit 50b for measuring the resistance value between the second contact parts (24, 26) in a pair. The first measuring unit 50a and the second measuring unit 50b are configured similarly to the first embodiment.

[0232] One terminal 52a of the supply source 52 in the first measurement section 50a is connected to the first current-carrying probe 30. The other terminal 52b of the supply source 52 in the first measurement section 50a is connected to the common second probe 36.

[0233] One terminal 54a of the voltage measuring section 54 in the first measuring section 50a is connected to the first measuring probe 32. The other terminal 54b of the voltage measuring section 54 in the first measuring section 50a is connected to the common first probe 34.

[0234] One terminal 52a of the supply source 52 in the second measurement section 50b is connected to the common first probe 34. The other terminal 52b of the supply source 52 in the second measurement section 50b is connected to the second current-carrying probe 40.

[0235] One terminal 54a of the voltage measuring section 54 in the second measuring section 50b is connected to the common second probe 36. The other terminal 54b of the voltage measuring section 54 in the second measuring section 50b is connected to the second measuring probe 42.

[0236] The measurement control unit 130 (see Figure 3 ) The first measuring unit 50a and the second measuring unit 50b are operated alternately to measure the first resistance value R between the first contact parts (22, 26) of the group. A The second resistance value R between the second contact parts (24, 26) of the group is measured before and after B The first measuring unit 50 a and the second measuring unit 50 b operate according to a control signal from the processing unit 100 .

[0237] The first measuring unit 50a supplies current from the supply source 52 to the object 16 when in operation. In addition, the first measuring unit 50a measures the voltage value of a predetermined portion of the object 16 by the voltage measuring unit 54 when in operation, and sends the measured voltage value to the processing unit 100 (see Figure 2 ).

[0238] The second measuring unit 50b supplies current from the supply source 52 to the object 16 when in operation. In addition, the second measuring unit 50b measures the voltage value of a predetermined portion of the object 16 by the voltage measuring unit 54 when in operation, and sends the measured voltage value to the processing unit 100 (see Figure 2 ).

[0239] The temperature acquisition unit 132 (see Figure 3 ) refers to the storage unit 110 (refer to Figure 2 ) information (140) (refer to Figure 8 ). Thus, the temperature acquisition unit 132 (refer to Figure 3 ) Based on the first resistance value R A The second resistance value R measured just before B The first resistance value R is measured A The second resistance value R measured immediately after B The average value of the first resistance value R is estimated and obtained. A The temperature t of the joint 18 at that time.

[0240] As described above, the measurement control unit 130 and the temperature acquisition unit 132 (see Figure 3 ) is performed by the processing unit 100 (refer to Figure 2 ) executes from the storage unit 110 (refer to Figure 2 ) is implemented by a software program that reads out.

[0241] (Function and Effect)

[0242] The effects obtained by the second embodiment will be described.

[0243] In the second embodiment, also with respect to the same or equivalent parts as those of the first embodiment, the same functions and effects as those of the first embodiment can be obtained.

[0244] In the second embodiment of the resistance measuring device 200, the measuring unit 50 includes: a first measuring unit 50a for measuring the resistance value between the first contact parts (22, 26) in a group; and a second measuring unit 50b for measuring the resistance value between the second contact parts (24, 26) in a group. The measurement control unit 130 causes the first measuring unit 50a and the second measuring unit 50b to operate alternately. A The second resistance value R is measured before and after B The temperature acquisition unit 132 refers to the information (140) stored in the storage unit 110, based on the first resistance value R A The second resistance value R measured just before B The first resistance value R is measured A The second resistance value R measured immediately after B The average value of the first resistance value R is estimated and obtained. A The temperature t of the joint 18 at that time.

[0245] In this structure, the measuring section 50 includes a first measuring section 50a for measuring the resistance value between the first contact sections (22, 26) and a second measuring section 50b for measuring the resistance value between the second contact sections (24, 26). Therefore, compared with the case where the measuring section 50 is composed of a single measuring section, the switching section 60 for switching between the first contact section (22, 26) and the second contact section (24, 26) connected to the measuring section 50 is not required. As a result, the resistance measuring device 200 can be made at a low cost.

[0246] In addition, the measurement control unit 130 causes the first measurement unit 50a and the second measurement unit 50b to operate alternately, and when measuring the first resistance value R A The second resistance value R is measured before and after B Therefore, the first resistance value R A The current and the second resistance value R B Compared with the case where the currents of the first resistance value R flow to the object 16 at the same time, the A The current used to determine the second resistance value R B Thus, the measurement control unit 130 can suppress the influence caused by the current interference.

[0247] Although the embodiments of the present invention have been described above, the above embodiments merely represent a part of application examples of the present invention and are not intended to limit the technical scope of the present invention to the specific structures of the above embodiments.

[0248] This application claims priority based on Japanese Patent Application No. 2022-144045 filed with the Japan Patent Office on September 9, 2022, and priority based on Japanese Patent Application No. 2023-100106 filed with the Japan Patent Office on June 19, 2023, the entire contents of which are incorporated into this specification by reference.

[0249] Description of Reference Numerals

[0250] 10: resistance measuring device; 12: first member; 14: second member; 16: object; 18: joint; 20: connection structure; 22: first contact portion; 24: second contact portion; 26: common contact portion; 50: measuring portion; 50a: first measuring portion; 50b: second measuring portion; 54: voltage measuring portion; 60: switching portion; 100: processing portion; 110: storage portion; 130: measurement control portion; 132: temperature acquisition portion; 134: calculation portion; 140: first information; 150: second information; R A : The first resistance value; R A0 : Reference resistance value; R B : second resistance value; t0: reference temperature; t1: specified temperature.

Claims

1. A resistance measuring device for measuring a reference resistance value of a joint portion at a preset reference temperature in an object formed by mutually joining a first member and a second member, wherein: The resistance measuring device comprises: a connecting structure having a set of first contact portions respectively contacting the first member and the second member, and a set of second contact portions contacting different portions of the second member; a measuring unit configured to measure a resistance value between the first contact portions in the group and a resistance value between the second contact portions in the group; a storage unit storing information indicating a relationship between a resistance value between the set of second contact portions and a temperature of the junction portion; a measurement control unit configured to form a state in which a first resistance value between the first contact portions forming a group is measured by the measurement unit and a state in which a second resistance value between the second contact portions forming a group is measured by the measurement unit; a temperature acquisition unit that acquires a temperature of the bonding portion based on the measured second resistance value and the information stored in the storage unit; as well as The calculation unit calculates the reference resistance value based on the acquired temperature of the bonding portion and the measured first resistance value.

2. The resistance measuring device according to claim 1, wherein: The measuring unit further comprises: a switching unit that selectively switches between a first connection state in which the first contact unit formed by the group is connected to the measuring unit and a second connection state in which the second contact unit formed by the group is connected to the measuring unit, The measurement control unit controls the switch unit to the first connection state so that the first resistance value is measured by the measurement unit, and controls the switch unit to the second connection state so that the second resistance value is measured by the measurement unit.

3. The resistance measuring device according to claim 2, wherein: One first contact portion in the set of first contact portions that contacts the second member and one second contact portion in the set of second contact portions are shared.

4. The resistance measuring device according to claim 2 or 3, wherein: The storage unit stores a calculation formula for calculating the reference resistance value based on the first resistance value and the temperature of the junction when the first resistance value is measured. The calculation unit calculates the reference resistance value based on the acquired temperature of the bonding portion, the measured first resistance value, and the calculation formula stored in the storage unit.

5. The resistance measuring device according to any one of claims 2 to 4, wherein: The measurement control unit alternately switches the connection state of the switch unit to measure the second resistance value before and after measuring the first resistance value. The temperature acquisition unit estimates and acquires the temperature of the joint when the first resistance value is measured based on the relationship between the second resistance value measured immediately before and the second resistance value measured immediately after the first resistance value is measured, by referring to the information stored in the storage unit.

6. The resistance measuring device according to claim 5, wherein: The relationship between the second resistance value measured immediately before the first resistance value is measured and the second resistance value measured immediately after the first resistance value is: the average value of the second resistance values ​​measured before and after the first resistance value is measured, When the average value of the second resistance value is acquired, the temperature acquisition unit refers to the information stored in the storage unit and acquires the temperature of the junction corresponding to the average value as the temperature of the junction when the first resistance value is measured.

7. The resistance measuring device according to claim 1, wherein: The measuring unit includes a first measuring unit that measures the resistance value between the first contact portions that form a group, and a second measuring unit that measures the resistance value between the second contact portions that form a group. The measurement control unit causes the first measurement unit and the second measurement unit to operate alternately, and measures the second resistance value before and after measuring the first resistance value. The temperature acquisition unit estimates and acquires the temperature of the joint when the first resistance value is measured based on the average value of the second resistance value measured immediately before and after the first resistance value is measured, by referring to the information stored in the storage unit.

8. The resistance measuring device according to any one of claims 1 to 7, wherein: The method further includes a coefficient calculation unit that calculates a resistance temperature coefficient of the junction portion based on data indicating a relationship between the plurality of first resistance values ​​and the plurality of second resistance values ​​acquired in a time series.

9. A method for measuring resistance, comprising measuring a reference resistance value of a joint portion at a preset reference temperature in an object formed by joining a first member and a second member to each other, wherein: The resistance measuring method comprises a set of first contact parts respectively contacting the first member and the second member, and a set of second contact parts contacting different portions of the second member. The resistance determination method performs: A process of measuring, by a measuring unit, a resistance value between the first contact portions forming the group and a resistance value between the second contact portions forming the group; A process of selectively switching between a first connection state in which the group of first contacts is connected to the measuring part and a second connection state in which the group of second contacts is connected to the measuring part; as well as a process of storing information indicating a relationship between a resistance value between the set of second contact portions and a temperature of the junction portion, Wherein, the resistance measuring method comprises: A measurement control process, measuring a first resistance value between the first contact portions in the group, and measuring a second resistance value between the second contact portions in the group; a temperature acquisition process of acquiring the temperature of the joint portion based on the measured second resistance value and the stored information; and The calculation step calculates the reference resistance value based on the acquired temperature of the bonding portion and the measured first resistance value.

10. The resistance measuring method according to claim 9, wherein: have: a first information acquisition process of acquiring first information indicating a relationship between the second resistance value and a temperature of the junction; In the first measurement process, the second connection state is set, and the second resistance value is measured by the measurement unit; a second preliminary measurement process, after the first preliminary measurement process, switching to the first connection state, and measuring the first resistance value by the measurement unit; a third preliminary measurement process, after the second preliminary measurement process, switching to the second connection state, and measuring the second resistance value by the measurement unit; as well as The preliminary estimation process estimates the resistance value between the second contact portions when the first resistance value is measured in the preliminary second measurement process as the second resistance value, using at least the second resistance value measured in the preliminary first measurement process and the second resistance value measured in the preliminary third measurement process.

11. The resistance measuring method according to claim 10, wherein: have: a preliminary temperature acquisition process of acquiring the temperature of the junction portion when the first resistance value is measured in the preliminary second measurement process based on the second resistance value estimated in the preliminary estimation process and the first information; a resistance temperature coefficient calculation process of calculating the resistance temperature coefficient of the junction part based on second information indicating a relationship between the first resistance value and the temperature of the junction part; as well as The calculation formula storage process stores a calculation formula for calculating the reference resistance value based on the resistance temperature coefficient of the junction portion acquired in the resistance temperature coefficient calculation process and the reference temperature.

12. The resistance measuring method according to claim 10 or 11, wherein: The first information acquisition process comprises: a predetermined temperature measuring process, in which the object is set to a predetermined temperature and brought into the second connection state, and the second resistance value is measured by the measuring unit; as well as The information generating process generates the first information based on the second resistance value measured in the predetermined temperature measuring process, the predetermined temperature, the resistance temperature coefficient of the second member, and the reference temperature.

13. The resistance measuring method according to any one of claims 10 to 12, wherein: The preliminary first measurement process to the preliminary third measurement process are acquired while the joint portion formed by joining the first member and the second member to each other is cooled.

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