Thermister assy and motor

Abstract

To provide a thermistor assy with which it is possible to easily attach a PTC thermistor element to a coil.SOLUTION: The thermistor assy includes a PTC thermistor element 2v, and a heat-shrinkable tubing 20 in which the PTC thermistor element 2v is accommodated. The PTC thermistor element 2v comprises a thermistor element body 10, a first thermistor leg 11 joined to the thermistor element body 10 via a first root part 11a, and a second thermistor leg 12 joined to the thermistor element body 10 via a second root part 12a. The heat-shrinkable tubing 20 is shrunk covering the thermistor element body 10, the first root part 11a, and the second root part 12a.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a thermistor assembly and a motor equipped with the same. [Background technology]

[0002] Patent Document 1 discloses a stator. The stator includes a coil, a thermistor, and a molded portion. The thermistor is disposed so as to abut against a surface of the coil. The thermistor includes a temperature sensor and a sensor case portion. The temperature sensor is configured to detect the temperature of the coil. The sensor case portion surrounds and holds the temperature sensor. The molded portion covers the coil and thermistor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-107889 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the above stator, an embedded type capped thermistor is used to prevent the thermistor from being damaged by the molding pressure when forming the molded portion. The embedded type capped thermistor has a cap like the above sensor case portion, a thermistor element body, and two lead wires connected to the thermistor element body. The thermistor element body is housed in the cap. Each lead wire has a core wire and an insulating coating formed on the outer periphery of the core wire. Each lead wire is connected to a respective thermistor foot of the thermistor element body inside the cap. The two lead wires are drawn out to the outside of the cap in a state parallel to each other.

[0005] The above-mentioned capped thermistor is attached to the coil end portion with the longitudinal direction of the cap aligned with the circumferential direction of the stator. However, in the case of a capped thermistor, the length dimension of the cap is often long. This poses a problem in that, depending on the width of the coil end portion in the circumferential direction of the stator, it may be difficult to attach the capped thermistor to the coil end portion.

[0006] The present invention has been made to solve the above-mentioned problems, and has an object to provide a thermistor assembly and a motor in which a PTC thermistor element can be easily attached to a coil. [Means for solving the problem]

[0007] The thermistor assembly of the present invention comprises a PTC thermistor element and a heat shrink tube containing the PTC thermistor element, wherein the PTC thermistor element has a thermistor element body, a first thermistor foot joined to the thermistor element body via a first root portion, and a second thermistor foot joined to the thermistor element body via a second root portion, and the heat shrink tube shrinks while covering the thermistor element body, the first root portion, and the second root portion.

[0008] The motor of the present invention comprises a stator having a stator core and a coil attached to the stator core, a rotor rotatably arranged relative to the stator, and a thermistor assembly that detects the temperature of the coil, wherein the thermistor assembly has a PTC thermistor element and a heat shrink tube that houses the PTC thermistor element, the PTC thermistor element having a thermistor element body, a first thermistor foot joined to the thermistor element body via a first root portion, and a second thermistor foot joined to the thermistor element body via a second root portion, the heat shrink tube shrinks while covering the thermistor element body, the first root portion, and the second root portion, the PTC thermistor element and the heat shrink tube are attached to the coil, and the PTC thermistor element, the heat shrink tube, and the coil are covered by a molded member. Effect of the Invention

[0009] According to the present invention, the PTC thermistor element can be easily attached to the coil. [Brief description of the drawings]

[0010] [Figure 1] 1 is a schematic diagram showing a configuration of a thermistor assembly according to a first embodiment. FIG. [Diagram 2] 2 is an enlarged schematic diagram showing the configuration of a PTC thermistor element of the thermistor assembly according to the first embodiment. FIG. [Diagram 3] 3 is a diagram showing an example of the arrangement positions of three PTC thermistor elements of a thermistor assembly in the motor according to the first embodiment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Embodiment 1 A thermistor assembly and a motor according to embodiment 1 will be described. Fig. 1 is a schematic diagram showing the configuration of a thermistor assembly according to the present embodiment. As shown in Fig. 1, the thermistor assembly 1 includes three PTC (Positive Temperature Coefficient) thermistor elements 2v, 2u, and 2w, and three heat shrink tubes 20 housing corresponding PTC thermistor elements.

[0012] The PTC thermistor element 2v is a thermistor element for the V phase that detects the temperature of the V phase coil. The PTC thermistor element 2u is a thermistor element for the U phase that detects the temperature of the U phase coil. The PTC thermistor element 2w is a thermistor element for the W phase that detects the temperature of the W phase coil. The PTC thermistor elements 2v, 2u, and 2w are all ceramic resistors having positive temperature characteristics. The PTC thermistor elements 2v, 2u, and 2w are connected in parallel to each other by multiple lead wires 30.

[0013] The PTC thermistor elements 2v, 2u, and 2w have the same configuration. The configuration of the PTC thermistor elements 2v, 2u, and 2w will be described below using the PTC thermistor element 2v as an example.

[0014] Fig. 2 is a schematic diagram showing an enlarged configuration of a PTC thermistor element of the thermistor assembly according to the present embodiment. As shown in Fig. 2, the PTC thermistor element 2v has a thermistor element body 10, a first thermistor foot 11, and a second thermistor foot 12. The thermistor element body 10 has a disk-like shape. The first thermistor foot 11 is joined to one electrode of the thermistor element body 10 via a first base portion 11a. The second thermistor foot 12 is joined to the other electrode of the thermistor element body 10 via a second base portion 12a.

[0015] The PTC thermistor element 2v is an exposed type thermistor element. For example, the PTC thermistor element 2v has a configuration that allows it to be through-hole mounted on a printed circuit board. The PTC thermistor element 2v is not of an embedded type, and is therefore not housed in a cap.

[0016] The heat shrink tube 20 shrinks while covering the thermistor element body 10, the first root portion 11a, and the second root portion 12a. As a result, at least the thermistor element body 10, the first root portion 11a, and the second root portion 12a of the PTC thermistor element 2v are protected by the heat shrink tube 20. Therefore, even if molding pressure is applied to the PTC thermistor element 2v, stress generated in the first root portion 11a and the second root portion 12a is alleviated.

[0017] When the heat shrink tube 20 is attached to the PTC thermistor element 2v, the thermistor element body 10, the first root portion 11a, and the second root portion 12a are inserted into the heat shrink tube 20 before shrinking, and the heat shrink tube 20 is shrunk by a heating treatment using a heat gun or the like. As a result, the heat shrink tube 20 covers the thermistor element body 10, the first root portion 11a, and the second root portion 12a, and is in close contact with the thermistor element body 10, the first root portion 11a, and the second root portion 12a.

[0018] The thermistor assembly 1 further includes a first lead wire 31, a second lead wire 32, a first protective tube 41, and a second protective tube .

[0019] The first lead wire 31 is one of the multiple lead wires 30. The first lead wire 31 is electrically connected to the first thermistor foot 11. The second lead wire 32 is the other of the multiple lead wires 30. The second lead wire 32 is electrically connected to the second thermistor foot 12. The first protective tube 41 protects the connection between the first lead wire 31 and the first thermistor foot 11. The second protective tube 42 protects the connection between the second lead wire 32 and the second thermistor foot 12. The first protective tube 41 and the second protective tube 42 are, for example, glass tubes.

[0020] The first thermistor foot 11 has a first root portion 11b, a first tip portion 11c, and a first bent portion 11d. The first root portion 11b is a portion of the first thermistor foot 11 on the first base portion 11a side. The first tip portion 11c is a portion provided on the tip side of the first thermistor foot 11 relative to the first root portion 11b. The first bent portion 11d is provided between the first root portion 11b and the first tip portion 11c.

[0021] The second thermistor foot 12 has a second root portion 12b, a second tip portion 12c, and a second bent portion 12d. The second root portion 12b is a portion of the second thermistor foot 12 on the second base portion 12a side. The second tip portion 12c is a portion provided on the tip side of the second thermistor foot 12 relative to the second root portion 12b. The second bent portion 12d is provided between the second root portion 12b and the second tip portion 12c.

[0022] The first root portion 11b and the second root portion 12b extend in the same direction from the thermistor element body 10. The first thermistor foot 11 is bent at the first bent portion 11d so that the first tip portion 11c is away from the second thermistor foot 12. The second thermistor foot 12 is bent at the second bent portion 12d so that the second tip portion 12c is away from the first thermistor foot 11. The first tip portion 11c and the second tip portion 12c extend, for example, on approximately the same straight line.

[0023] The first lead wire 31 and the second lead wire 32 each have a core wire and an insulating coating formed around the core wire. The first lead wire 31 extends along both the second tip portion 12c and the first tip portion 11c. At one end portion 31a of the first lead wire 31, the insulating coating is removed to expose the core wire. The one end portion 31a of the first lead wire 31 is electrically connected to the first tip portion 11c of the first thermistor leg 11 by soldering.

[0024] When connecting the first lead wire 31 and the first thermistor foot 11, one end 31a of the first lead wire 31 is wound around the first tip 11c of the first thermistor foot 11 while the first tip 11c of the first thermistor foot 11 is extended in a straight line. This prevents the first thermistor foot 11 from being twisted, thereby preventing a load from being applied to the first thermistor foot 11. The first tip 11c and the one end 31a are then connected by soldering. An insulating tape is then wrapped around the connection between the first tip 11c and the one end 31a.

[0025] The second lead wire 32 extends along both the first tip 11c and the second tip 12c. At one end 32a of the second lead wire 32, the insulating coating is removed to expose the core wire. The one end 32a of the second lead wire 32 is electrically connected to the second tip 12c of the second thermistor leg 12 by soldering.

[0026] When connecting the second lead wire 32 and the second thermistor foot 12, one end 32a of the second lead wire 32 is wound around the second tip 12c of the second thermistor foot 12 while the second tip 12c of the second thermistor foot 12 is extended in a straight line. This prevents the second thermistor foot 12 from being twisted, thereby preventing a load from being applied to the second thermistor foot 12. The second tip 12c and the one end 32a are then connected by soldering. An insulating tape is then wrapped around the connection between the second tip 12c and the one end 32a.

[0027] The first tip portion 11c of the first thermistor foot 11 and one end portion 31a of the first lead wire 31, together with the second lead wire 32, are covered by the first protective tube 41. As a result, the connection portion between the first tip portion 11c and the one end portion 31a is protected by the first protective tube 41 and is integrated with the second lead wire 32.

[0028] The second tip portion 12c of the second thermistor foot 12 and one end portion 32a of the second lead wire 32, together with the first lead wire 31, are covered by the second protective tube 42. As a result, the connection portion between the second tip portion 12c and the one end portion 32a is protected by the second protective tube 42 and is integrated with the first lead wire 31.

[0029] The first bent portion 11d of the first thermistor leg 11 is covered by a third protective tube 51. The first thermistor leg 11 is passed through the inside of the third protective tube 51 from the first tip portion 11c side. One end of the third protective tube 51 is covered by a heat shrink tube 20. The other end of the third protective tube 51 is covered by a first protective tube 41. As a result, the parts of the first thermistor leg 11, such as the first bent portion 11d, that are not covered by other tubes are protected by the third protective tube 51. The third protective tube 51 is, for example, a flexible tube made of fluororesin.

[0030] The second bent portion 12d of the second thermistor leg 12 is covered by a fourth protective tube 52. The second thermistor leg 12 is passed through the inside of the fourth protective tube 52 from the second tip portion 12c side. One end of the fourth protective tube 52 is covered by a heat shrink tube 20. The other end of the fourth protective tube 52 is covered by a second protective tube 42. As a result, the second bent portion 12d and other parts of the second thermistor leg 12 that are not covered by other tubes are protected by the fourth protective tube 52. The fourth protective tube 52 is, for example, a flexible tube made of fluororesin.

[0031] Fig. 3 is a diagram showing an example of the arrangement of three PTC thermistor elements of a thermistor assembly in a motor according to this embodiment. Note that the structure of the thermistor assembly 1 shown in Fig. 3 does not necessarily match the structure of the thermistor assembly 1 shown in Figs. 1 and 2.

[0032] As shown in Fig. 3, the motor includes a stator 80, a rotor 90, and a thermistor assembly 1. The stator 80 has a stator core 81 and a plurality of coils 82 attached to the stator core 81. The rotor 90 is rotatably provided relative to the stator 80. A current flows through each coil 82, which is supplied via a motor wire 83. The motor wires 83 are bundled by a glass tube 84. The thermistor assembly 1 is configured to detect the temperature of the coils 82.

[0033] The PTC thermistor element 2v of the thermistor assembly 1 is attached to the surface of the coil end portion of the V-phase coil among the multiple coils 82 while being housed in a heat shrink tube 20 (not shown). The PTC thermistor element 2u is attached to the surface of the coil end portion of the U-phase coil among the multiple coils 82 while being housed in a heat shrink tube 20 (not shown). The PTC thermistor element 2w is attached to the surface of the coil end portion of the W-phase coil among the multiple coils 82 while being housed in a heat shrink tube 20 (not shown).

[0034] The PTC thermistor elements 2v, 2u, 2w are covered by a molded member (not shown), together with the heat shrink tube 20 housing the PTC thermistor elements 2v, 2u, 2w, and the coil end portions of the coils 82. As a result, in the completed motor, the PTC thermistor elements 2v, 2u, 2w and the heat shrink tube 20 housing the PTC thermistor elements 2v, 2u, 2w are not exposed to the outside.

[0035] As described above, the thermistor assembly 1 according to the present embodiment includes the PTC thermistor elements 2v, 2u, and 2w, and the heat shrink tube 20 that houses the PTC thermistor elements 2v, 2u, and 2w. Each of the PTC thermistor elements 2v, 2u, and 2w has a thermistor element body 10, a first thermistor foot 11, and a second thermistor foot 12. The first thermistor foot 11 is joined to the thermistor element body 10 via a first base portion 11a. The second thermistor foot 12 is joined to the thermistor element body 10 via a second base portion 12a. The heat shrink tube 20 shrinks while covering the thermistor element body 10, the first base portion 11a, and the second base portion 12a.

[0036] According to this configuration, the thermistor element body 10, first root portion 11a, and second root portion 12a of each of the PTC thermistor elements 2v, 2u, and 2w are protected by the heat shrink tube 20. Therefore, even if an external force due to molding pressure or the like is applied to each of the PTC thermistor elements 2v, 2u, and 2w, the stress generated in the first root portion 11a and the second root portion 12a is alleviated. Therefore, even if each of the PTC thermistor elements 2v, 2u, and 2w is not housed in a cap, it is possible to prevent the thermistor element body 10, first root portion 11a, and second root portion 12a from being damaged by an external force due to molding pressure or the like.

[0037] Furthermore, this configuration allows the use of an uncapped PTC thermistor element, which makes it possible to shorten the length of the PTC thermistor element compared to a thermistor with a cap, and therefore makes it possible to easily attach the PTC thermistor element to the coil end portion of the coil 82 regardless of the size of the coil end portion.

[0038] The thermistor assembly 1 according to this embodiment further includes a first lead wire 31, a first protective tube 41, a second lead wire 32, and a second protective tube 42. The first lead wire 31 is electrically connected to the first thermistor foot 11. The first protective tube 41 protects the connection between the first thermistor foot 11 and the first lead wire 31. The second lead wire 32 is electrically connected to the second thermistor foot 12. The second protective tube 42 protects the connection between the second thermistor foot 12 and the second lead wire 32.

[0039] The first thermistor leg 11 has a first root portion 11b, a first tip portion 11c, and a first bent portion 11d. The first tip portion 11c is provided closer to the tip side of the first thermistor leg 11 than the first root portion 11b. The first bent portion 11d is provided between the first root portion 11b and the first tip portion 11c.

[0040] The second thermistor leg 12 has a second root portion 12b, a second tip portion 12c, and a second bent portion 12d. The second tip portion 12c is provided closer to the tip side of the second thermistor leg 12 than the second root portion 12b. The second bent portion 12d is provided between the second root portion 12b and the second tip portion 12c.

[0041] The first root portion 11b and the second root portion 12b extend in the same direction from the thermistor element body 10. The first thermistor foot 11 is bent at the first bent portion 11d so that the first tip portion 11c is away from the second thermistor foot 12. The second thermistor foot 12 is bent at the second bent portion 12d so that the second tip portion 12c is away from the first thermistor foot 11.

[0042] The first lead wire 31 extends along both the second tip portion 12c and the first tip portion 11c. One end portion 31a of the first lead wire 31 is electrically connected to the first tip portion 11c. The second lead wire 32 extends along both the first tip portion 11c and the second tip portion 12c. One end portion 32a of the second lead wire 32 is electrically connected to the second tip portion 12c. The first tip portion 11c and one end portion 31a of the first lead wire 31, together with the second lead wire 32, are covered by a first protective tube 41. The second tip portion 12c and one end portion 32a of the second lead wire 32, together with the first lead wire 31, are covered by a second protective tube 42.

[0043] According to this configuration, the connection portion between first tip portion 11c and one end 31a is protected by the first protective tube 41 and is integrated with the second lead wire 32. Moreover, the connection portion between second tip portion 12c and one end 32a is protected by the second protective tube 42 and is integrated with the first lead wire 31. Therefore, even if an external force due to molding pressure or the like is applied to each of the PTC thermistor elements 2v, 2u, 2w, damage to the PTC thermistor elements 2v, 2u, 2w can be more reliably prevented.

[0044] The thermistor assembly 1 according to this embodiment further includes a third protective tube 51 and a fourth protective tube 52. The first thermistor foot 11 is passed through the inside of the third protective tube 51. The second thermistor foot 12 is passed through the inside of the fourth protective tube 52. The first bent portion 11d is covered by the third protective tube 51. The second bent portion 12d is covered by the fourth protective tube 52.

[0045] According to this configuration, the first bent portion 11d is protected by the third protective tube 51. The second bent portion 12d is protected by the fourth protective tube 52. Therefore, even if an external force due to molding pressure or the like is applied to each of the PTC thermistor elements 2v, 2u, 2w, damage to the PTC thermistor elements 2v, 2u, 2w can be more reliably prevented.

[0046] The motor according to this embodiment includes a stator 80, a rotor 90, and a thermistor assembly 1. The stator 80 has a stator core 81 and a plurality of coils 82 attached to the stator core 81. The rotor 90 is provided rotatably relative to the stator 80. The thermistor assembly 1 is configured to detect the temperature of the coils 82.

[0047] The thermistor assembly 1 has PTC thermistor elements 2v, 2u, 2w and a heat shrink tube 20 that houses the PTC thermistor elements 2v, 2u, 2w. Each of the PTC thermistor elements 2v, 2u, 2w has a thermistor element body 10, a first thermistor foot 11, and a second thermistor foot 12. The first thermistor foot 11 is joined to the thermistor element body 10 via a first base portion 11a. The second thermistor foot 12 is joined to the thermistor element body 10 via a second base portion 12a. The heat shrink tube 20 shrinks while covering the thermistor element body 10, the first base portion 11a, and the second base portion 12a.

[0048] The PTC thermistor element 2v and the heat shrink tube 20 housing the PTC thermistor element 2v are attached to one of the multiple coils 82. The PTC thermistor element 2u and the heat shrink tube 20 housing the PTC thermistor element 2u are attached to another of the multiple coils 82. The PTC thermistor element 2w and the heat shrink tube 20 housing the PTC thermistor element 2w are attached to yet another of the multiple coils 82. The PTC thermistor elements 2v, 2u, 2w, the heat shrink tubes 20 housing the PTC thermistor elements 2v, 2u, 2w, and the multiple coils 82 are covered with a molded member.

[0049] With this configuration, even if the molding pressure when forming the molded member is applied to each of the PTC thermistor elements 2v, 2u, 2w, the stress generated in the first root portion 11a and the second root portion 12a is alleviated. Therefore, even if each of the PTC thermistor elements 2v, 2u, 2w is not housed in a cap, the thermistor element body 10, the first root portion 11a, and the second root portion 12a can be prevented from being damaged.

[0050] Furthermore, this configuration allows the use of uncapped PTC thermistor elements, which makes it possible to shorten the length of the PTC thermistor elements compared to capped thermistors, and therefore allows the PTC thermistor elements 2v, 2u, and 2w to be easily attached to the coil end portions of the coil 82, regardless of the dimensions of the coil end portions.

[0051] In the above embodiment, the thermistor assembly 1 has three PTC thermistor elements 2v, 2u, and 2w, but this is not limited to this. The number of PTC thermistor elements included in the thermistor assembly 1 may be one, two, or four or more. [Explanation of symbols]

[0052] 1 thermistor assembly, 2u, 2v, 2w PTC thermistor element, 10 thermistor element body, 11 first thermistor leg, 11a first root portion, 11b first base portion, 11c first tip portion, 11d first bent portion, 12 second thermistor leg, 12a second root portion, 12b second base portion, 12c second tip portion, 12d second bent portion, 20 heat shrink tube, 30 lead wire, 31 first lead wire, 31a one end portion, 32 second lead wire, 32a one end portion, 41 first protective tube, 42 second protective tube, 51 third protective tube, 52 fourth protective tube, 80 stator, 81 stator core, 82 coil, 83 motor wire, 84 glass tube, 90 rotor.

Claims

1. A PTC thermistor element (2v); A heat shrink tube (20) containing the PTC thermistor element (2v); Equipped with The PTC thermistor element (2v) is A thermistor element body (10); a first thermistor leg (11) joined to the thermistor element body (10) via a first base portion (11a); a second thermistor leg (12) joined to the thermistor element body (10) via a second base portion (12a); It has The heat shrink tube (20) is a thermistor assembly that shrinks while covering the thermistor element body (10), the first base portion (11a), and the second base portion (12a).

2. a first lead wire (31) electrically connected to the first thermistor foot (11); a first protective tube (41) for protecting a connection between the first thermistor foot (11) and the first lead wire (31); a second lead wire (32) electrically connected to the second thermistor foot (12); a second protective tube (42) for protecting a connection between the second thermistor foot (12) and the second lead wire (32); Further equipped with The first thermistor leg (11) is A first root portion (11b); a first tip portion (11c) provided closer to the tip side of the first thermistor leg (11) than the first root portion (11b); a first bent portion (11d) provided between the first root portion (11b) and the first tip portion (11c); It has The second thermistor leg (12) is A second root portion (12b); a second tip portion (12c) provided closer to the tip of the second thermistor leg (12) than the second root portion (12b); a second bent portion (12d) provided between the second root portion (12b) and the second tip portion (12c); It has The first root portion (11b) and the second root portion (12b) extend in the same direction from the thermistor element body (10), The first thermistor foot (11) is bent at the first bent portion (11d) so that the first tip portion (11c) is away from the second thermistor foot (12), The second thermistor foot (12) is bent at the second bent portion (12d) so that the second tip portion (12c) is away from the first thermistor foot (11), The first lead wire (31) extends along both the second tip portion (12c) and the first tip portion (11c), One end (31a) of the first lead wire (31) is electrically connected to the first tip portion (11c), The second lead wire (32) extends along both the first tip portion (11c) and the second tip portion (12c), One end (32a) of the second lead wire (32) is electrically connected to the second tip portion (12c), the first tip portion (11c) and the one end portion (31a) of the first lead wire (31) are covered by the first protective tube (41) together with the second lead wire (32); 2. The thermistor assembly according to claim 1, wherein the second tip portion (12c) and the one end portion (32a) of the second lead wire (32) are covered by the second protective tube (42) together with the first lead wire (31).

3. a third protective tube (51) through which the first thermistor leg (11) is passed; a fourth protective tube (52) through which the second thermistor leg (12) is passed; Further equipped with The first bent portion (11d) is covered by the third protective tube (51), 3. The thermistor assembly according to claim 2, wherein the second bent portion (12d) is covered by the fourth protective tube (52).

4. A stator (80) having a stator core (81) and a coil (82) attached to the stator core (81); a rotor (90) rotatably provided relative to the stator (80); a thermistor assembly (1) for detecting the temperature of the coil (82); Equipped with The thermistor assembly (1) is A PTC thermistor element (2v); A heat shrink tube (20) containing the PTC thermistor element (2v); It has The PTC thermistor element (2v) is A thermistor element body (10); a first thermistor leg (11) joined to the thermistor element body (10) via a first base portion (11a); a second thermistor leg (12) joined to the thermistor element body (10) via a second base portion (12a); It has the heat shrink tube (20) shrinks while covering the thermistor element body (10), the first base portion (11a), and the second base portion (12a); The PTC thermistor element (2v) and the heat shrink tube (20) are attached to the coil (82); The PTC thermistor element (2v), the heat shrink tube (20) and the coil (82) are covered with a molding member.

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