JP2013246084A - Probe and resistance measuring apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To measure a resistance value of a measuring object without peeling an insulation coating of the measuring object.SOLUTION: A resistance measuring apparatus includes: current probes 11, 21; and voltage probes 12, 22. Both probes have the sharp tip shapes for cutting a part of insulation coating 40b in order to contact a conductor 40a of enamel wire 40.

Description

  The present invention relates to a probe for measuring resistance of a measurement object provided with an insulating film, and a resistance measuring apparatus.

  In order to suppress the influence of the contact resistance between the measurement object and the electrode and accurately measure the resistance value of the measurement object, resistance measurement by a four-terminal method is generally used. For example, in order to measure the resistance value of a coil wire of a motor using this four-terminal method, an insulating film covering the surface of the coil wire is used to secure electrical communication between the electrode and the coil wire. The resistance value is measured after performing an operation of peeling off by heating or an operation of removing by heating.

  Patent Document 1 discloses a configuration in which resistance measurement is performed by reliably bringing the tip of a probe into contact with a measurement target. The probe of Patent Document 1 includes a columnar voltage probe and a cylindrical current probe that is coaxially disposed so as to surround the voltage probe, and the tip of the voltage probe is formed in a conical shape and the current probe. It is made to project by projecting from it, and a tip part provided with biasing means is attached to the exposed part. At the time of resistance measurement, the biasing means provided on the tip part contracts by pressing the tip part attached to the tip part of the voltage probe against the object to be measured, and the conical tip part of the voltage probe is pressed against the object to be measured. The resistance measurement by the four-terminal method can be performed in a state in which the tip of the electrode is in contact with the object to be measured.

JP 2007-178311 A

  However, the conventional operation of mechanically peeling off the insulating coating described above has a problem that it takes time to peel off and the productivity is remarkably lowered. Furthermore, since a blade or a file is used as the insulating film peeling means, there is a problem that maintenance of these peeling means is required. In addition, the above-described conventional operation for removing the insulating film by heating requires a large apparatus for heating the coil wire, and smoke generated when the insulating film formed of resin is heated and melted. In addition, there is a problem that a process for recovering and cleaning the odor is required.

  Furthermore, in the technique disclosed in Patent Document 1 described above, even if the conical tip is brought into contact with the measurement object by the contraction force of the urging means, the conical tip cannot penetrate the insulating coating. In addition, there is a problem that an operation for separating the insulating coating is required.

  The present invention has been made to solve the above-described problems, and provides a probe capable of measuring a resistance value without peeling off an insulating film of a measurement object, and a resistance measurement apparatus using the probe. For the purpose.

  The probe according to the present invention includes a current probe and a voltage probe, and both probes have a sharp tip shape that cuts a part of the insulating film in order to contact the measurement object.

  According to this invention, the resistance value of the measurement object can be measured without peeling off the insulating film of the measurement object.

It is explanatory drawing which shows resistance measurement of the four terminal method using the probe by Embodiment 1. FIG. FIG. 3 is a diagram showing a configuration of a probe according to the first embodiment. 3 is a top view of the probe according to Embodiment 1. FIG. 3 is a side view of the probe according to Embodiment 1. FIG. It is a figure which shows the assembly | attachment of the probe and drive mechanism by Embodiment 1. FIG. It is a figure which shows the structure of the resistance measuring device carrying the probe by Embodiment 1. FIG. It is a figure which shows the other structure of the probe by Embodiment 1. FIG.

Embodiment 1 FIG.
FIG. 1 is an explanatory diagram showing resistance measurement by a four-terminal method using a probe according to Embodiment 1 of the present invention.
The resistance measurement of the four-terminal method in the first embodiment is performed using a pair of probes 10 and 20 and a resistance measuring instrument 30 connected to the pair of probes 10 and 20.
The pair of probes 10 and 20 includes current probes 11 and 21, voltage probes 12 and 22, and current probes 11 and 21 and insulators 13 and 23 sandwiched between the voltage probes 12 and 22, respectively. The resistance measuring device 30 includes a current generating unit 31 and a voltage measuring unit 32, and current probes 11 and 21 for supplying power are connected to the current generating unit 31, and the voltage measuring unit 32 has a voltage probe for measuring voltage. 12 and 22 are connected.

  When measuring the resistance value, for example, a pair of probes 10, 20 are arranged near both ends of an enameled wire (conductive wire that is an object to be measured) 40 in which a coil wire (conductor) of a motor is covered with an insulating film. The tip portion is pressed and brought into contact, and a current for measurement is supplied from the current generating portion 31 to the conductor of the enameled wire 40 via the current probes 11 and 21. Thus, the voltage measurement unit 32 measures the potential difference generated at both ends of the conductor. A voltage value is obtained from the measured potential difference between the two points, and a resistance value (R) 50 of the conductor is obtained from the obtained voltage value and a current value for measurement.

FIG. 2 is a diagram showing the configuration of the probe according to Embodiment 1 of the present invention. 2A is a top view of the current probe, FIG. 2B is a top view of the voltage probe, and FIG. 2C is a top view of the insulator. In FIG. 2, the probe 10 will be described as an example of the pair of probes 10 and 20.
As shown in FIG. 2A, the current probe 11 includes a tip portion 11 a that cuts a part of the insulating film of the enameled wire 40 and applies a current by contacting the conductor, and a current generator of the resistance measuring device 30. 31 is provided with a current side connection terminal 11 b for connection to the terminal 31.

Further, as shown in FIG. 2B, the voltage probe 12 includes a tip 12 a that cuts a part of the insulating film of the enamel wire 40 and contacts the conductor to measure a potential difference, and a voltage measurement of the resistance measuring device 30. The voltage side connection terminal 12b for connecting with the part 32 is provided.
Further, as shown in FIG. 2C, the insulator 13 is formed of a substantially rectangular insulating plate having an abutting surface 13a that abuts against the insulating coating of the enameled wire.

  The length A in the short direction of the current probe 11 and the voltage probe 12 is longer than the length B in the longitudinal direction of the insulator 13 by a predetermined amount. A pair of screw holes 11c, 12c, and 13b are formed in the current probe 11, the voltage probe 12, and the insulator 13, respectively. By inserting and fixing screws into the screw holes 11c, 12c, and 13b, the current probe 11, the voltage probe 12, and the insulator 13 are fixed to each other to constitute the probe 10. At the time of assembly, the current probe 11, the voltage probe 12, and the insulators 13 are aligned and fixed so that the side surfaces facing the tip portions 11a, 12a, and 13a coincide with each other. As a result, the contact surface 13 a of the insulator 13 is positioned inside the probe 10 relative to the tip portion 11 a of the current probe 11 and the tip portion 12 a of the voltage probe 12.

FIG. 3 is a top view of the probe according to Embodiment 1 of the present invention. In FIG. 3, the probe 10 will be described as an example of the pair of probes 10 and 20.
The probe 10 is formed by stacking a current probe 11 shown in FIG. 2A, an insulator 13 shown in FIG. 2C, and a voltage probe 12 shown in FIG. , 12c and 13b are fixed to each other by inserting screws. When the members are overlapped with each other, they are aligned so that the side surfaces facing the tip portions 11a, 12a, and 13a coincide with each other, and are fixed with screws.

  The current probe 11 and the voltage probe 12 overlap each other except for the region where the current side contact terminal 11b and the voltage side contact terminal 12b are formed. The current side contact terminal 11b and the voltage side contact terminal 12b are arranged so that the respective terminals are exposed so that they can be connected to the current generating unit 31 and the voltage measuring unit 32.

4 is a side view of the probe according to the first embodiment of the present invention, FIG. 4 (a) is a side view showing an overall view of the probe, and FIG. 4 (b) is a tip portion of the probe during resistance measurement. FIG. Also in FIG. 4, the probe 10 will be described as an example of the pair of probes 10 and 20.
As shown in FIGS. 4A and 4B, the probe 10 is superposed in the order of the current probe 11, the insulator 13, and the voltage probe 12. The enameled wire 40 is formed by covering a conductive conductor 40a with an insulating coating 40b.

  When the distal end portion 11a of the current probe 11 and the distal end portion 12a of the voltage probe 12 are pressed against the enameled wire 40, a part of the insulating coating 40b is cut so that the most advanced portion can reach the central portion of the conductor 40a. It has a sharp shape. Various methods for forming the tip portions 11a, 12a at an acute angle are conceivable. As shown in FIG. 4, an inclined surface 11d is provided in the vicinity of the tip portion 11a of the current probe 11, and the insulator between the inclined surface 11d and the current probe 11 is provided. It joins so that the side surface on the 13th side forms an acute angle. Similarly, an inclined surface 12d is provided in the vicinity of the distal end portion 12a of the voltage probe 12, and the inclined surface 12d and the side surface of the voltage probe 12 on the insulator 13 side are joined so as to form an acute angle.

  By forming the tip portion 11a of the current probe 11 and the tip portion 12a of the voltage probe 12 at an acute angle, when the probe 10 is pressed against the enameled wire 40, the tip portion 11a of the current probe 11 and the tip portion of the voltage probe 12 12a cuts a part of the insulating coating 40b of the enameled wire 40 to reach the vicinity of the center of the conductor 40a, the current is applied and the potential difference is measured, and the resistance value (R) 50 of the conductor is measured.

  The angles of the tips 11a and 12a of the current probe 11 and the voltage probe 12 are acute angles that are not plastically deformed by the reaction force received from the insulating coating 40b of the enamel wire 40 and the conductor 40a when the probe 10 is pressed against the enamel wire 40. An angle. Further, the current probe 11 and the voltage probe 12 are materials having physical properties and rigidity that are not plastically deformed by a reaction force from the conductor 40a and the insulating coating 40b of the enameled wire 40, and materials having conductivity that can ensure electrical conduction. Consists of. For example, steel is used. The current probe 11 and the voltage probe 12 made of steel or the like are subjected to surface treatment using rust prevention, low electrical resistance, and a hard coating material.

  On the other hand, by disposing the insulator 13 between the current probe 11 and the voltage probe 12, the current generation unit 31 and the voltage measurement unit 32 of the resistance measuring device 30 are insulated. Since the contact surface 13a of the insulator 13 is disposed so as to be located inside the probe 10 relative to the tip portion 11a of the current probe 11 and the tip portion 12a of the voltage probe 12, the probe 10 is pressed against the enamel wire 40. When the tip portions 11a and 12a of the current probe 11 and the voltage probe 12 are positioned near the center of the conductor 40a, the contact surface 13a of the insulator 13 is the outer surface of the insulating coating 40b of the enameled wire 40. Abut. That is, the contact surface 13a of the insulator 13 functions as a stopper for adjusting the insertion of the current probe 11 and the voltage probe 12 into the enamel wire 40. As a result, the sharp tip portions 11a and 12a of the current probe 11 and the voltage probe 12 can be prevented from being completely cut and divided by the enamel wire 40, and the tip portions 11a and 12a can be kept at positions where resistance can be measured. .

  To what extent the contact surface 13a of the insulator 13 is positioned inside the probe 10 with respect to the tip portion 11a of the current probe 11 and the tip portion 12a of the voltage probe 12 (of the length B shown in FIG. 2C) The setting value is determined in consideration of the thickness of the insulating coating 40b of the enameled wire 40 and the wire diameter of the conductor 40a. Specifically, the distal end portions 11a and 12a are resisted by arranging the contact surface 13a of the insulator 13 about half the wire diameter of the enameled wire 40 in the inner direction of the probe 10 with respect to the distal end portions 11a and 12a. It can be kept at a measurable position. By adjusting the length B (see FIG. 2C) of the contact surface 13a of the insulator 13, the probe 10 can be applied to the enameled wire 40 of any wire diameter.

  As described above, the insulator 13 functions to insulate the current measuring unit 31 and the voltage measuring unit 32 of the resistance measuring device 30, and the sharp tip portions 11a and 12a of the current probe 11 and the voltage probe 12 divide the enameled wire 40. And a stopper function for preventing the Therefore, the thickness of the insulator 13 in the short direction is equal to or longer than the shortest distance necessary to insulate the current generator 31 and the voltage measurement unit 32, and when the probe 10 is pressed against the enamel wire 40, It is set to a value that can maintain a contact surface pressure that can prevent the current probe 11 and the voltage probe 12 from being inserted by a predetermined amount or more. By bringing the current generation unit 31 and the voltage measurement unit 32 closer to the shortest distance necessary to insulate, the contact resistance can be canceled and a minute resistance value can be measured.

The probe 10 configured as described above is assembled to the drive mechanism, and the tip portions 11a and 12a of the probe 10 are pressed against the enamel wire 40 by the moving operation of the drive mechanism. FIG. 5 is a diagram showing the assembly of the probe and the drive mechanism according to the first embodiment of the present invention.
The probe 10 is set on the mounting table 60. By inserting the screws inserted into the screw holes 11c, 13b, 12c (see FIG. 4) provided in the current probe 11, the insulator 13 and the voltage probe 12 into the screw holes provided in the corresponding positions of the installation base 60, the probe 10 and the mounting table 60 are fixed. The mounting table 60 can be appropriately configured as long as it does not hinder the operation of pressing the tip portions 11a, 12a of the probe 10 against the enamel wire 40.

  A driving mechanism 70 is connected to the mounting table 60. The drive mechanism 70 is connected to, for example, a control unit (not shown) that electrically controls the operation. The drive mechanism 70 includes a housing 71 including an air cylinder that performs a pressing operation, and two piston rods 72 that perform a linear motion in a predetermined direction in accordance with the pressing operation of the air cylinder. The outer circumferences of the two piston rods 72 are each covered with two covers 73. One end portions 72 a and 73 a of the two piston rods 72 and the two covers 73 penetrate the side surface of the housing 71 and are movably connected to the air cylinder. On the other hand, the other end portions 72 b and 73 b of the two piston rods 72 and the two covers 73 are fixed to the side surface of the mounting table 60.

  When the air cylinder in the housing 71 feeds compressed air into the two piston rods 72, the piston rods 72 reciprocate in the respective guides 73 in the direction of the arrow XX ′. By this reciprocation, the mounting table 60 fixed to the end portions 72b of the two piston rods 72 reciprocates in the direction of the arrow XX ', and the probe 10 fixed to the mounting table 60 is similarly arrow XX. Operates in the 'direction.

  The wire near the end of the enameled wire 40 is disposed so as to be substantially orthogonal to the arrow XX ′ direction, which is the direction of operation of the probe 10, and substantially orthogonal to the longitudinal direction of the distal end portions 11 a and 12 a of the probe 10. . In addition, a receiving wall 80 is provided that comes into contact with a wire near the end of the enamel wire 40 when the probe 10 moves in the direction of the arrow X. As a result, when the probe 10 moves in the arrow X direction, the tip portions 11 a and 12 a of the probe 10 press the wire rod near the end portion of the enameled wire 40 against the wall 80. Due to the pressing force against the receiving wall 80, the tip portions 11a and 12a of the probe 10 cut a part of the insulating coating 40b and come into contact with the conductor 40a. By disposing the receiving wall 80, the distal end portions 11 a and 12 a of the probe 10 can be reliably brought into contact with the enamel wire 40.

  In the assembling example shown in FIG. 5, a configuration using a dual rod cylinder as the drive mechanism 70 is shown. However, any configuration may be used as long as the configuration allows the probe 10 to move in the direction of the arrow XX ′. Moreover, although the structure using an air cylinder was shown in FIG. 5, you may comprise with a hydraulic cylinder.

Next, a resistance measuring apparatus equipped with the probe 10 and the drive mechanism 70 shown in FIG. 5 will be described.
FIG. 6 is a diagram showing a configuration of a resistance measuring instrument equipped with the probe according to the first embodiment of the present invention. 6A is a view of the resistance measuring device viewed from above, FIG. 6B is a view of FIG. 6A viewed from the direction of arrow C, and FIG. 6C is a view of FIG. It is the figure seen from the direction. In FIG. 6A, the description of the installation base on which the wound enamel wire 40 is installed is omitted, and the receiving wall 80 is shown by a dotted line. In FIG. 6C, the receiving wall 80 is not shown.

  The resistance measuring apparatus 100 operates the pair of probes 10 and 20, the mounting tables 60 and 60 ′ for fixing the pair of probes 10 and 20, the probes 10 and 20 and the mounting tables 60 and 60 ′ in the direction of the arrow XX ′. Drive mechanism 70, 70 ′, wound enamel wire 40, installation base 90 for installing the wound enamel wire 40, receiving wall 80 provided near the enamel wire 40 suspended from the installation base 90, probe 10 , 20 and a resistance measuring instrument (not shown) for measuring the resistance value of the enameled wire 40.

  The wound enamel wire 40 is arranged on the upper part of the installation table 90. A receiving wall 80 is disposed below the installation table 90, and a wire 40c in the vicinity of the end of the enameled wire 40 along a plane facing the tips 11a, 12a, 21a, and 22a of the probes 10 and 20 of the receiving wall 80. , 40d is suspended. The probe 10 is arranged at a position where the wire rod 40c of the suspended enamel wire 40 and the tip portions 11a, 12a can come into contact with each other, and the wire material 40d of the suspended enamel wire 40 and the tip portions 21a, 22a can be brought into contact with each other. The probe 20 is arranged. The probe 10 is arranged on a mounting table 60 connected to the driving mechanism 70, and the probe 20 is arranged on a mounting table 60 'connected to the driving mechanism 70'.

  Further, as shown in FIG. 6 (c), the wire rods 40c and 40d near the end of the enameled wire 40 hang down so as to be substantially orthogonal to the width direction of the tips 11a, 12a, 21a and 22a of the probes 10 and 20. Is done. Further, the positions of the wire rods 40c and 40d of the suspended enameled wire 40 may swing left and right (the range of the arrow Y in FIG. 6C). Therefore, the longitudinal widths of the distal end portions 11a, 12a, 21a, and 22a of the probes 10 and 20 are configured to have a length that is longer than the range of the arrow Y. As a result, even when the wire rods 40c and 40d of the enameled wire 40 swung left and right, the tips 11a, 12a, 21a and 22a of the probes 10 and 20 can be reliably brought into contact with each other.

  When the probe 10 is moved in the direction of the arrow X by the operation of the drive mechanism 70, the tip portions 11a and 12a of the probe 10 press the wire 40c of the enameled wire 40 against the receiving wall 80, and the tip portions 11a and 12a insulate the contact portion. A part of the coating 40b is cut and brought into contact with the conductor 40a. Similarly, when the probe 20 moves in the direction of the arrow X by the operation of the drive mechanism 70 ', the distal end portions 21a and 22a of the probe 20 press the wire rod 40d of the enameled wire 40 against the receiving wall 80, and the distal end portions 21a and 22a A part of the insulating coating 40b at the contact portion is cut to contact the conductor 40a.

  In this way, when the tip portions 11a, 12a, 21a, and 22a of the probes 10 and 20 are in contact with the conductors 40a of the wire rods 40c and 40d near the ends of the wound enamel wire 40, the circuit shown in FIG. The resistance is measured by the four probe method.

  In the first embodiment, the tip portions of the probes 10 and 20 have been described by taking the shape shown in FIG. 4 as an example. However, a part of the insulating coating 40b of the enameled wire 40 can be cut and contacted with the conductor 40a. Any configuration can be appropriately changed. For example, as shown in FIG. 7A, the tips of the current probe 11 and the voltage probe 12 may be sharp angled tip portions 11a ′ and 12a ′. Further, as shown in FIG. 7B, a plurality of acute angle-shaped shapes may be arranged at the distal ends of the current probe 11 and the voltage probe 12 to form the distal end portions 11a ″ and 12a ″.

  As described above, according to the first embodiment, the current probe 11 having the sharp tip portion 11a and the voltage probe 12 having the sharp tip portion 12a are provided. Since the probe 10 is configured by disposing the insulator 13 between them, when the probe 10 is pressed against the enameled wire 40, the sharp tip portions 11a and 12a cut a part of the insulating coating 40b of the enameled wire 40. The conductor 40a can be contacted. As a result, the resistance value can be measured without removing the insulating coating of the coil wire, and the productivity can be improved.

  Further, according to the first embodiment, the contact surface 13 a of the insulator 13 is positioned in the predetermined direction of the probe 10 with respect to the tip portion 11 a of the current probe 11 and the tip portion 12 a of the voltage probe 12. Since the insulator 13 maintains the function of insulating the current generator 31 and the voltage measuring unit 32 of the resistance measuring device 30, the tip 11a of the current probe 11 and the tip 12a of the voltage probe 12 are enameled. It is possible to prevent the wire 40 from being completely cut and divided.

  Further, according to the first embodiment, the thickness of the insulator 13 in the short direction is not less than the shortest distance necessary for insulating the current generating unit 31 and the voltage measuring unit 32, and the probe 10 is Since the contact surface pressure is set to a value that can prevent the insertion of the current probe 11 and the voltage probe 12 more than a predetermined amount when pressed against the enameled wire 40, the four-terminal method is used. By canceling the contact resistance, it is possible to measure a minute resistance value, and further it is possible to prevent the probe 10 from completely cutting and dividing the coil wire.

  Further, according to the first embodiment, the enameled wire 40 is made of steel having rigidity that does not undergo plastic deformation due to the reaction force from the conductor 40a and the insulating coating 40b, and is also rust-proof and low in resistance. Since the current probe 11 and the voltage probe 12 subjected to surface treatment using electrical resistance and a hard coating material are used, it is possible to form a probe having both the function of cutting the insulating film and the durability. .

  In the first embodiment described above, the description has been made on the assumption that resistance measurement is performed using four terminals. However, the present invention can also be applied to resistance measurement using two terminals.

  In the present invention, any constituent element of the embodiment can be modified or any constituent element of the embodiment can be omitted within the scope of the invention.

  10, 20 probe, 11, 21 Current probe, 11a, 11a ′, 11a ″, 12a, 12a ′, 12a ″, 21a, 22a Tip, 11b Current side contact terminal, 11c, 12c, 13b Screw hole, 11d , 12d Inclined surface, 12, 22 Voltage probe, 12b Voltage side contact terminal, 13 Insulator, 13a Contact surface, 30 Resistance measuring device, 31 Current generator, 32 Voltage measuring unit, 40 Enamelled wire, 40a Conductor, 40b Insulation Coating, 40c, 40d wire, 50 resistance, 60 mounting table, 70, 70 'drive mechanism, 71 housing, 72 piston rod, 72a, 72b, 73a, 73b end, 73 guide, 80 receiving wall, 90 mounting table, 100 Resistance measuring device.

Claims (6)

A current probe for supplying a current to a measurement object to which an insulating film is applied; and a voltage probe for measuring a voltage of the measurement object to which a current is supplied by the current probe; and a current supplied by the current probe In the probe that measures the resistance value of the measurement object based on the value of and the voltage value measured by the voltage probe,
The current probe and the voltage probe have a sharp tip shape that cuts a part of the insulating film in order to contact the measurement object.   The probe according to claim 1, wherein the current probe and the voltage probe constitute a probe set laminated via an insulator. Two sets of the probe set are provided,
The probe according to claim 2, wherein a resistance value of the measurement object is measured by a four-terminal method. The measurement object is a conductive wire,
The insulators of the probe set are in contact with the outer surface of the insulating film until the tips of the current probe and the voltage probe reach at least the center of the conductive wire, thereby leading the tips of the current probe and the voltage probe. The probe according to claim 2, wherein movement of the conductive wire in the center direction is restricted.   The current probe and the voltage probe of the probe set are wide on the side in contact with the conductive wire, and the insulator of the probe set is wide on the side in contact with the outer surface of the insulating coating, The probe according to claim 4. In a resistance measuring device that measures the resistance value of a conductive wire coated with an insulating film,
A current probe that supplies current to the conductive wire and a voltage probe that measures the voltage of the conductive wire supplied with current by the current probe are stacked via an insulator, and both probes are Two probe sets each having a sharp tip shape for cutting a part of the insulating coating to contact the conductive wire,
A drive mechanism for moving the two probe sets toward and away from the conductive wire;
A receiving wall portion on which tips of the current probe and the voltage probe of the two probe sets moved by the driving mechanism press the conductive wire;
When the tips of the current probe and the voltage probe of the two sets of probe sets are brought into contact with the conductive wires by the movement of the drive mechanism, the current probes of the two sets of probe sets are supplied to the conductive wires. And a resistance measuring instrument for measuring the resistance value of the conductive wire by a four-terminal method using the measured current value and the voltage value measured by the voltage probe of the two probe sets. A resistance measuring device characterized by the above.

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