JP2011259549A - Temperature detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve temperature detection accuracy of a coil for an electric motor.SOLUTION: The temperature detector is equipped with a thermometric element 22, a resin bracket 26 and a metal bracket 30. The resin bracket 26 has a base 27, arms 28a and 28b, and claws 29a and 29b. The cross section of the base 27 with the arms 28a and 28b, which extend from both ends of the base 27, is U-shaped, and the claws 29a and 29b extend inward from both ends of the arms 28a and 28b to store the thermometric element 22. The claws 28a and 29b hook on a conducting wire 16 at its back from the view of the base 27 to mount the resin bracket 26 on the conducting wire 16. The metal bracket 30 is stored in the resin bracket 26 and holds the thermometric element 22. When the claws 29a and 29b of the resin bracket 26 are hooked on the conducting wire 16, the metal bracket 30 is brought into contact with the conducting wire 16 and the base 27 of the resin bracket 26 and biases them in a direction to separate from each other. Thus, heat conduction between the conducting wire 16 and the thermometric element 22 occurs through the metal bracket 30, so that the temperature of the conducting wire 16 at the end part 14 of the coil 12 is accurately detected.

Description

  The present invention relates to a temperature detector.

  Conventionally, a temperature detection element insertion hole for inserting a temperature detection element and a locking part for fixing the temperature detection element are integrally formed in a resin mold portion that molds a coil end portion of a coil wound around a stator with resin. A thermistor as a temperature detection element is inserted into a temperature detection insertion hole and locked to a locking portion (for example, see Patent Document 1). In this technology, by integrally forming the temperature detection element hole and the locking portion, it is possible to accurately fix the temperature detection element to the stator by suppressing variation in the relative position between them, and to detect the temperature for each product. Variation in the contact area between the element and the temperature detection element insertion hole (variation in measurement accuracy) is suppressed.

JP 2009-100538 A

  In the above-described method, since the temperature of the coil is generally detected by a thermistor through a resin mold portion having a relatively large thermal resistance, it is difficult to further improve the temperature detection accuracy. For this reason, it is considered as one of the problems to improve the temperature detection accuracy of the coil by a method (temperature detector) different from the above-described method.

  The main object of the temperature detector of the present invention is to improve the temperature detection accuracy of the coil of the electric motor.

  The temperature detector of the present invention employs the following means in order to achieve the main object described above.

The temperature detector of the present invention is
A temperature detector for detecting the temperature of a coil wound around a stator of an electric motor,
A temperature sensor,
A cross-section is formed in a shape in which a claw portion extends inward from both ends of a U-shape consisting of a base portion and arm portions extending from both ends of the base portion, the temperature measuring element is accommodated, and the claw portion is An attachment member attached to the lead wire by being hooked on the back side of the lead wire of the coil end portion of the coil as seen from the base;
It is made of a metal that is housed in the mounting member, holds the temperature measuring element, and urges the base portion and the lead wire in contact with each other when the claw portion is hooked on the lead wire so that they are separated from each other. A biasing member;
It is a summary to provide.

  In this temperature detector of the present invention, the cross section is formed in a shape in which the claw portion extends inward from the U-shaped both ends including the base portion and the arm portion extending from both ends of the base portion. A temperature measuring element is accommodated, and a claw part is attached to the conductor by hooking it to the back side of the coil end portion of the coil as viewed from the base, and the temperature sensor is held in the attachment member and is attached to the mounting member. A metal urging member that contacts the base of the mounting member and the conductor when the claw is hooked on the conductor, and urges the two in a direction away from each other. Therefore, when the claw portion of the attachment member is hooked on the conducting wire, the urging force acts on the conducting wire and the base portion of the attachment member by the metal urging member, thereby positioning the temperature measuring element. Then, heat conduction between the conducting wire and the temperature measuring element is performed by the metal urging member, so that the temperature of the conducting wire at the coil end portion of the coil can be detected with higher accuracy.

  In such a temperature detector of the present invention, the urging member may be formed to be symmetrical with respect to a straight line passing through the base and the temperature measuring element. Further, the mounting member may be made of a resin having a lower thermal conductivity than the biasing member. Furthermore, a protection member that covers the temperature measuring element may be provided, and the biasing member may be a member that holds the temperature measuring element via the protection member.

It is a block diagram which shows the outline of a structure of the stator 10 of the electric motor with which the temperature detector 20 as one Example of this invention was attached. It is the AA view which looked at the temperature detector 20 of FIG. 1 from the AA surface. It is the BB view which looked at the temperature detector 20 of FIG. 1 from the BB surface. It is a block diagram which shows the outline of a structure of the temperature detector 20b of a modification.

  Next, the form for implementing this invention is demonstrated using an Example.

  FIG. 1 is a configuration diagram showing an outline of the configuration of a stator 10 of an electric motor to which a temperature detector 20 as an embodiment of the present invention is attached, and FIG. 2 shows the temperature detector 20 of FIG. FIG. 3 is a BB view of the temperature detector 20 of FIG. 1 viewed from the BB plane. In FIG. 1, the coil end portion 14 is hatched for easy viewing.

  A coil 12 is wound around the stator 10 of the electric motor. As shown in FIGS. 1 to 3, a temperature detector 20 is attached to the conductive wire 16 of the coil end portion 14 of the coil 12. In addition, the conducting wire 16 is covered with an insulator having a thickness of about several tens of μm made of enamel or the like with a strand made of copper or the like, and has a substantially rectangular cross section (see FIG. 2). Further, in FIG. 2, it seems that the conducting wire 16 is arranged on the upper portion of the coil end portion 14, but this is schematically shown.

  The temperature detector 20 includes a temperature measuring element 22, a protective member 24 configured as a resin insulating tube that covers the temperature measuring element 22, and a resin mounting member that accommodates the temperature measuring element 22 and is attached to the lead wire 16. As a metal urging member that contacts the base 27 and the conductive wire 16 of the resin bracket 26 while holding the temperature measuring element 22 through the protective member 24 and being accommodated in the resin bracket 26. Bracket 30.

  As the temperature measuring element 22, for example, a thermistor or a thermocouple having a diameter of several millimeters can be used. In addition, the protective member 24 is formed to a thickness of about several tens to several hundreds of μm by using, for example, a fluororesin such as polytetrafluoroethylene or a silicon resin. The detection value detected by the temperature measuring element 22 is input to a computer (not shown) via the lead wire 40 connected to the temperature measuring element 22. Then, in consideration of the detection value of the temperature measuring element 22, the computer outputs the target torque to the rotating shaft connected to the rotor of the electric motor, for example, within a range where the temperature of the coil 12 does not exceed the allowable temperature. Control the motor.

  The resin bracket 26 is formed of a resin having a lower thermal conductivity than the metal bracket 30 such as a fluororesin such as polytetrafluoroethylene, PPS, or aromatic nylon. The resin bracket 26 has a thickness of about several millimeters, and as shown in FIG. 2, the cross section in the width direction of the conducting wire 16 extends from the both ends of the base 27 and the base 27 at a substantially right angle to the base 27. The claw portions 29a and 29b are formed in the shape of the U-shape from both ends of the U-shape (the tips of the arm portions 28a and 28b) formed of 28a and 28b, and the claw portions 29a and 29b are the base portions. It is attached to the conducting wire 16 by being caught on the back side of the conducting wire 16 as viewed from 27. That is, when viewed in the axial direction of the electric motor (viewed from the front side in FIG. 1), the claws 29a and 29b of the resin bracket 26 are hooked to the rear side in the axial direction (the rear side in FIG. 1) with respect to the conductive wire 16. Is attached to the conductor 16. Also, the resin bracket 26 is formed so as to cover the temperature measuring element 22, a part of the protective member 24, and the metal bracket 30 in the direction of the conductive wire 14 (see FIG. 3). The resin bracket 26 has a function of suppressing the transfer of heat between the inside and the outside of the resin bracket 26 and suppressing the contact of the cooling oil to the temperature measuring element 22 when the electric motor is cooled by the cooling oil. .

  The metal bracket 30 is made of a metal having a higher thermal conductivity than that of the resin bracket 26 such as iron or copper. The metal bracket 30 is formed symmetrically with respect to a straight line passing through the approximate center of the base portion 27 of the resin bracket 26 and the temperature measuring element 22 (refer to a one-dot chain line in FIG. 2, hereinafter referred to as a detector center line). A first abutting portion 32 that abuts the base 27 of the resin bracket 26, a holding portion 34 that holds the temperature measuring element 22 by covering the outer periphery of the temperature measuring element 22 via the protective member 24, and the resin bracket 26. A second abutting portion 36 that abuts the conducting wire 16 when attached to the conducting wire 16, a base 27 side (upper side in FIG. 2) of the resin bracket 26, and claw portions 29a, 29b side (lower side in FIG. 2). And an elastic portion 38 having a spring shape (elastic structure) for urging the spring. Here, the first contact portion 32 may be fixed to the base portion 27 of the resin bracket 26 or may not be fixed. 2 is longer than the difference (L1-L2) between the length L1 from the base portion 27 of the resin bracket 26 to the claw portions 29a, 29b and the thickness L2 of the conductive wire 16 in FIG. Is formed. Therefore, when the resin bracket 26 is attached to the conductive wire 16, the urging force (elastic force) by the elastic portion 38 acts in a direction in which the base portion 27 of the resin bracket 26 and the conductive wire 16 come into contact with each other and the two are separated from each other. In the embodiment, since the metal bracket 30 is formed symmetrically with respect to the center line in the detector, a substantially equal force acts on the conductive wire 16 and the base portion 27 of the resin bracket 26 on both sides of the center line in the detector. Therefore, variation in the position of the temperature measuring element 22 when the temperature detector 20 is attached to the conducting wire 16 can be suppressed.

  In the temperature detector 20 configured in this way, when the claws 29a and 29b of the resin bracket 26 are hooked on the conductive wire 16, the urging force is applied in the direction in which the conductive wire 16 and the base 27 of the resin bracket 26 are separated by the metal bracket 30. By acting, positioning of the temperature measuring element 22 within the resin bracket 26 is performed. The metal bracket 30 conducts heat conduction between the conducting wire 16 and the temperature measuring element 22, whereby the temperature of the conducting wire 16 of the coil end portion 14 of the coil 12 can be detected with higher accuracy. In the embodiment, a protective member 24 made of resin is interposed between the conductor 14 and the temperature measuring element 22, but the temperature measuring element is inserted into a resin mold part in which the coil end part is molded with resin, and the temperature of the conductor is measured. Since the distance (thickness) of the resin between the lead wire 14 and the temperature measuring element 22 is sufficiently short as compared with that for detecting the temperature, the thermal resistance between the lead wire 14 and the temperature measuring element 22 is made sufficiently small. It is considered possible. In such a temperature detector 20, the area of the second contact portion 36 of the metal bracket 30 that makes contact with the conducting wire 16 is increased, or the area that covers the temperature measuring element 22 of the holding portion 34 of the metal bracket 30 is increased. It is preferable to do. The former is to suppress the variation in the position of the temperature measuring element 22 or to improve the temperature detection accuracy by the temperature measuring element 22, and the latter is to suppress the temperature variation in the temperature measuring element 22.

  According to the temperature detector 20 of the embodiment described above, the temperature measuring element 22 and the cross section in the width direction of the conducting wire 16 are composed of the base portion 27 and the arm portions 28a and 28b extending from both ends of the base portion 27. Claw portions 29a, 29b are formed in a U-shaped inner side from both ends of the U-shape, receive the temperature measuring element 22, and the claw portions 29a, 29b are located on the back side of the conductor 16 when viewed from the base 27. The resin bracket 26 attached to the conductive wire 16 by being hooked, and holding the temperature measuring element 22 accommodated in the resin bracket 26, and when the claws 29a and 29b of the resin bracket 26 are hooked on the conductive wire 16, the conductive wire 16 and the resin bracket A metal bracket 30 that comes into contact with the base portion 27 of the 26 and urges them away from each other. Since heat conduction between is performed, it is possible to detect more accurately the temperature of the wire 16 of the coil end portion 14 of the coil 12.

  In the temperature detector 20 of the embodiment, the metal bracket 30 is formed symmetrically with respect to the center line within the detector, but may not be formed symmetrically with respect to the center line within the detector. . In this case, for example, as illustrated in the temperature detector 20b of the modified example of FIG. 4, by one first contact portion 32b, a holding portion 34, two second contact portions 36, and one elastic portion 38b. The metal bracket 30b may be formed.

  In the temperature detector 20 of the embodiment, the temperature measuring element 22 is covered with the protection member 24, but may be not covered with the protection member 24. If it carries out like this, the heat conduction of the conducting wire 16 and the temperature measuring element 22 can be improved more.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problems will be described. In the embodiment, the temperature measuring element 22 corresponds to the “temperature measuring element”, the resin bracket 26 corresponds to the “mounting member”, and the metal bracket 30 corresponds to the “biasing member”.

  Here, the temperature measuring element is not limited to a thermistor or a thermocouple, and any type of temperature measuring element may be used. The “mounting member” is not limited to the resin bracket 26, and the cross section has a shape in which a claw portion extends inward from both ends of a U-shape including a base portion and arm portions extending from both ends of the base portion. As long as the temperature measuring element is accommodated and the claw portion is attached to the lead wire by being hooked on the back side of the lead wire of the coil end portion of the coil as viewed from the base portion, any device may be used. The “urging member” is not limited to the metal bracket 30 and is housed in the mounting member, holds the temperature measuring element, and comes into contact with the base and the conductor when the claw is hooked on the conductor. Any metal may be used as long as it is energized in the direction in which the two are separated from each other.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problem is the same as that of the embodiment described in the column of means for solving the problem. Therefore, the elements of the invention described in the column of means for solving the problems are not limited. That is, the interpretation of the invention described in the column of means for solving the problems should be made based on the description of the column, and the examples are those of the invention described in the column of means for solving the problems. It is only a specific example.

  As mentioned above, although the form for implementing this invention was demonstrated using the Example, this invention is not limited at all to such an Example, In the range which does not deviate from the summary of this invention, it is with various forms. Of course, it can be implemented.

  The present invention is applicable to a temperature detector.

  10 Stator, 12 Coil, 14 Coil End, 16 Conductor, 20 Temperature Detector, 20b Temperature Detector, 22 Temperature Sensor, 24 Protection Member, 26 Resin Bracket, 27 Base, 28a, 28b Arm, 29a, 29b Claw part, 30, 30b Metal bracket, 32, 32b First contact part, 34 Holding part, 36 Second contact part, 38, 38b Elastic part, 40 Lead wire.

Claims (4)

A temperature detector for detecting the temperature of a coil wound around a stator of an electric motor,
A temperature sensor,
A cross-section is formed in a shape in which a claw portion extends inward from both ends of a U-shape consisting of a base portion and arm portions extending from both ends of the base portion, the temperature measuring element is accommodated, and the claw portion is An attachment member attached to the lead wire by being hooked on the back side of the lead wire of the coil end portion of the coil as seen from the base;
It is made of a metal that is housed in the mounting member, holds the temperature measuring element, and urges the base portion and the lead wire in contact with each other when the claw portion is hooked on the lead wire so that they are separated from each other. A biasing member;
A temperature detector. The temperature detector according to claim 1,
The biasing member is formed so as to be symmetric with respect to a straight line passing through the base and the temperature measuring element.
Temperature detector. The temperature detector according to claim 1 or 2, wherein
The mounting member is made of a resin having a lower thermal conductivity than the biasing member.
Temperature detector. A temperature detector according to any one of claims 1 to 3,
A protective member covering the temperature measuring element;
The biasing member is a member that holds the temperature measuring element via the protection member.
Temperature detector.

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