Busbar temperature sensor and busbar module

Abstract

To provide a bus bar temperature sensor and a bus bar module which are highly responsive and can precisely measure the temperature of a bus bar.SOLUTION: A temperature sensor 1 used by being attached to a bus bar 2 includes a heat sensing element and a case part 4 containing the heat sensing element. The bus bar includes a first extension unit 2a, a second extension unit 2b extending in parallel to the first extension unit, a connection unit 2c for connecting the respective top end parts of the first extension unit and the second extension unit to each other, and an attachment space S between the first extension unit and the second extension unit facing each other. The case part has a fitting unit 5 which can be fit in the attachment space in a pressed state, and the fitting unit has a plurality of protruding parts 5a formed in a surface in contact with one of the first extention unit and the second extension unit facing the attachment space.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a bus bar temperature sensor and a bus bar module that are attached to bus bars used as wiring members for motor stators, batteries, etc. [Background technology]

[0002] Some bus bars used as wiring components for motor stators, batteries, etc. are known to be equipped with temperature sensors to detect the temperature of the bus bars. For example, motor stators can become very hot, so control using a temperature sensor is essential. BACKGROUND ART For example, Patent Document 1 discloses a conventional temperature detection device that uses a metal bracket to attach a temperature sensor to a coil. Furthermore, Patent Document 2 describes a stator for a rotating electrical machine that includes a neutral conductor that is connected to a stator coil and has a U-shaped portion that is bent into a U shape, and a temperature sensor that is in contact with the neutral conductor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6674070 [Patent Document 2] Japanese Patent Application Publication No. 2018-61389 Summary of the Invention [Problem to be solved by the invention]

[0004] The above conventional techniques still have the following problems. In other words, in the above-mentioned conventional technology, because the mounting holder such as a bracket and the rectangular wire such as the neutral wire cross, there is a problem that rattle occurs when the temperature sensor is mounted, and the heat receiving surface of the temperature sensor is not securely attached, resulting in a decrease in the accuracy of temperature measurement. Also, when an insulating varnish or the like is used as a fixing method, if there is a variation in the wrapping of the insulating varnish between the mounting holder or rectangular wire and the heat receiving surface of the temperature sensor, there is also a problem that the heat receiving performance is affected.

[0005] The present invention has been made in view of the above-mentioned problems, and has an object to provide a busbar temperature sensor and a busbar module that can measure the temperature of a busbar with high accuracy by reliably bringing the heat-receiving surface into close contact with the busbar. [Means for solving the problem]

[0006] The present invention employs the following configuration to solve the above problems. That is, a busbar temperature sensor according to a first invention is a temperature sensor attached to a busbar, comprising: a heat-sensitive element; and a case portion in which the heat-sensitive element is housed; the busbar includes a first extension portion, a second extension portion extending parallel to the first extension portion, and a connecting portion connecting a tip end of the first extension portion to a tip end of the second extension portion, and an installation space is defined between the first extension portion and the second extension portion, which are opposed to each other; the case portion has a fitting portion that can be press-fitted into the installation space; and a plurality of protrusions are formed on a surface of the fitting portion that faces the installation space and contacts one of the first extension portion and the second extension portion.

[0007] In this busbar temperature sensor, the fitting portion has multiple protrusions formed on the surface that contacts one of the first and second extension portions facing the mounting space, and the multiple protrusions are crushed when the fitting portion is fitted into the mounting space, generating a biasing force that stably maintains the press-fit state. This ensures that the surface (heat-receiving surface) of the fitting portion that contacts the other of the first and second extension portions is at least reliably in close contact with the other of the first and second extension portions, ensuring heat reception and enabling highly accurate temperature measurement.

[0008] The busbar temperature sensor according to a second invention is characterized in that, in the first invention, the fitting portion has an upper flange portion and a lower flange portion whose diameter is larger than that of the mounting space, the upper flange portion can be engaged with the upper surfaces of the first extension portion and the second extension portion around the mounting space, and the lower flange portion can be engaged with the lower surfaces of the first extension portion and the second extension portion around the mounting space. In other words, in this busbar temperature sensor, the upper flange portion can be engaged with the upper surfaces of the first and second extension portions around the mounting space, and the lower flange portion can be engaged with the lower surfaces of the first and second extension portions around the mounting space.Therefore, the upper and lower flange structure prevents the temperature sensor from coming loose or tilting from the mounting space, and also serves as a guide when fitting it into the mounting space.

[0009] The busbar temperature sensor according to the third invention is characterized in that, in the first or second invention, the convex portion is a protruding portion extending in a direction perpendicular to the fitting direction into the mounting space. In other words, in this busbar temperature sensor, the convex portion is a protruding portion that extends in a direction perpendicular to the fitting direction into the mounting space, and the convex portion of the protruding portion, which has a rib structure, can provide high resistance to the force that tries to pull it out in the opposite direction to the fitting direction by pressing it in, thereby providing a high prevention effect against pulling it out in the opposite direction.

[0010] The busbar temperature sensor according to the fourth invention is characterized in that, in any one of the first to third inventions, a direction mark indicating the fitting direction into the mounting space is displayed on the surface of the fitting portion. That is, in this bus bar temperature sensor, a direction mark indicating the direction of insertion into the installation space is displayed on the surface of the insertion portion, so that it can be attached to the bus bar in the correct insertion direction.

[0011] A busbar module according to a fifth aspect of the present invention is characterized by comprising: a busbar; a busbar temperature sensor according to any one of the first to fourth aspects of the present invention attached to the busbar; and a resin molded portion that seals the fitting portion together with a part of the busbar. That is, this busbar module includes a molded resin portion that seals the fitting portion together with a portion of the busbar, and the fitting portion, which is stably held in a press-fit state by the multiple protrusions, is then sealed with the molded resin portion by injection molding or the like, thereby achieving even higher fixation of the temperature sensor and improved moisture resistance, shock resistance, etc. Also, heat from the portion of the busbar can be transferred to the fitting portion via the molded resin portion, allowing for more accurate temperature measurement.

[0012] A bus bar module according to a sixth invention is the bus bar module of the fifth invention, characterized in that the resin molded portion also seals the second extending portion and the connecting portion. That is, in this busbar module, the resin molded portion also seals the second extension portion and the connecting portion, so that the fitting portion can be firmly sealed together with the surrounding second extension portion and connecting portion, and heat from the second extension portion and the connecting portion can be transferred to the fitting portion via the resin molded portion, allowing temperature to be measured with higher accuracy.

[0013] A busbar module according to a seventh aspect of the present invention is characterized in that the busbar temperature sensor is the busbar temperature sensor of the second aspect of the present invention, and the lower flange portion and the upper flange portion have expanded diameters only on the surface side where the convex portion is not formed. In other words, in this busbar module, the lower flange portion and the upper flange portion are expanded in diameter only on the surface side where the convex portion is not formed, and are not expanded in diameter on the surface side where the convex portion is formed, so that the lower flange portion and the upper flange portion do not get in the way when sealing with resin using the resin molding portion, making it easier to fill the resin between the convex portions. In this way, when the resin of the resin molding part is filled into the gaps between the multiple convex parts, the spaces between the multiple convex parts are filled with resin, increasing the contact area and achieving high thermal conductivity at the contact surface having the convex parts.

[0014] A busbar module according to an eighth aspect of the present invention is the busbar module of any one of the fifth to seventh aspects of the present invention, characterized in that the busbar temperature sensor is the busbar temperature sensor of the third aspect of the present invention, and the protrusion portion is cut midway. That is, in this bus bar module, the protrusions are cut halfway, so that resin can be easily filled between the protrusions through the cut portions when sealing with resin using the resin molding portion.

[0015] A bus bar module according to a ninth invention is the bus bar module of any one of the fifth to eighth inventions, characterized in that the bus bar is used in a motor stator. In other words, in this bus bar module, since the bus bar is used in the motor stator, the temperature of the motor stator can be measured with high accuracy and stability by the fitting portion of the temperature sensor, which is securely in contact with the heat-receiving surface. [Effects of the Invention]

[0016] According to the present invention, the following effects are achieved. In other words, according to the busbar temperature sensor and busbar module of the present invention, multiple protrusions are formed on the surface of the fitting portion that contacts one of the first extension portion and the second extension portion facing the mounting space, so that the press-fit state is maintained stably, the surface (heat-receiving surface) that contacts the first extension portion and the second extension portion is reliably in close contact, and highly accurate temperature measurement is possible. As described above, the bus bar temperature sensor and bus bar module of the present invention have a heat receiving surface that is securely in close contact with the substrate, making them suitable for highly accurate temperature measurement of bus bars such as motor stators. [Brief explanation of the drawings]

[0017] [Figure 1] 1A is a perspective view showing a state of the busbar temperature sensor before fitting and FIG. 1B is a perspective view showing a state of the busbar temperature sensor after fitting in the first embodiment of the busbar temperature sensor and busbar module according to the present invention. [Figure 2]3 is a cross-sectional view of a main part showing a state in which the bus bar temperature sensor is fitted into the bus bar in the first embodiment. FIG. [Figure 3] FIG. 2 is a perspective view showing a bus bar module in the first embodiment. [Figure 4] FIG. 4 is a cross-sectional view taken along line AA in FIG. [Figure 5] FIG. 10 is a perspective view showing a state after the busbar temperature sensor has been fitted in a second embodiment of the busbar temperature sensor and busbar module according to the present invention. [Figure 6] FIG. 10 is a front view showing a state after the bus bar temperature sensor has been fitted in the second embodiment. [Figure 7] FIG. 10 is a perspective view showing a bus bar module in a second embodiment. [Figure 8] 10A and 10B are perspective views showing a state before and after fitting of the busbar temperature sensor in a third embodiment of the busbar temperature sensor and busbar module according to the present invention. [Figure 9] FIG. 11 is a plan view showing a state after the bus bar temperature sensor has been fitted in the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0018] A first embodiment of a busbar temperature sensor and a busbar module according to the present invention will be described below with reference to Figures 1 to 4. Note that the scale of some of the drawings used in the following description has been changed as necessary to make each part recognizable or easily recognizable.

[0019] As shown in Figures 1 to 4, the busbar temperature sensor 1 of this embodiment is a temperature sensor that is attached to a busbar 2 and used, and includes a heat-sensitive element 3 and a case portion 4 in which the heat-sensitive element 3 is housed. The busbar 2 includes a first extension portion 2a, a second extension portion 2b extending parallel to the first extension portion 2a, and a connecting portion 2c connecting the tip ends of the first extension portion 2a and the second extension portion 2b, and has an installation space S between the first extension portion 2a and the second extension portion 2b which face each other. The bus bar 2 is used in a motor stator, and the bus bar temperature sensor 1 of this embodiment detects the temperature of the coil conductor of the motor stator.

[0020] The case portion 4 has a fitting portion 5 that can be fitted into the mounting space S in a press-fit state. The fitting portion 5 has a surface that faces the mounting space S and comes into contact with one of the first extending portion 2a and the second extending portion 2b, and on this surface a plurality of protrusions 5a are formed.

[0021] The protrusions 5a are ridges extending in a direction perpendicular to the fitting direction into the mounting space S. That is, the protrusions 5a are ridges extending in the thickness direction (vertical direction) of the busbar 2. In addition, in the fitting portion 5 of this embodiment, a plurality of protrusions 5a are formed on the surface that faces the mounting space S and comes into contact with the second extending portion 2b. In this embodiment, three protrusions 5a are formed as protrusions.

[0022] The fitting portion 5 has an upper flange portion 5b and a lower flange portion 5c each having a diameter larger than that of the mounting space S. The upper flange portion 5b can be engaged with the upper surfaces of the first extension portion 2a and the second extension portion 2b around the mounting space S, and the lower flange portion 5c can be engaged with the lower surfaces of the first extension portion 2a and the second extension portion 2b around the mounting space S.

[0023] On the surface of the fitting portion 5, a direction mark 5d indicating the fitting direction into the installation space S is displayed. In this embodiment, the upper surface of the fitting portion 5 is formed with a plurality of arrow-shaped V-shaped protrusions as direction marks 5d. As shown in Figure 4, the thermal element 3 includes a sealing glass portion 3a that covers a chip thermistor (not shown) mounted on a substrate (not shown) with glass, and a resin coating portion 3b that covers the sealing glass portion 3a with resin. A pair of lead wires 3c is connected to the heat sensitive element 3, and a pair of electric wires 3d is connected to the pair of lead wires 3c. The resin coating portion 3b is formed so as to cover the pair of lead wires 3c as well.

[0024] The space between the heat-sensitive element 3 and the case 4 is filled with an insulating adhesive resin 7 . The case part 4 has a square cylindrical case lower part 4a below the fitting part 5, which covers the electric wire 3d up to the middle. The adhesive resin 7 is also filled in the lower case portion 4a. The adhesive resin 7 may be an insulating resin such as a silicone resin or an epoxy resin, and is preferably a resin with good thermal conductivity.

[0025] The fitting portion 5 has a rectangular cross section, and as shown in FIG. 2, when fitted into the mounting space S, the outer circumferential surface comes into contact with the inner surfaces of the first extending portion 2a, the second extending portion 2b, and the connecting portion 2c. In particular, the outer peripheral surface of the fitting portion 5 and the inner surfaces of the second extending portion 2b and the connecting portion 2c are in close contact with each other.

[0026] As shown in Figures 3 and 4, the busbar module 10 of this embodiment includes a busbar 2, the busbar temperature sensor 1 attached to the busbar 2, and a resin molded portion 11 that seals the fitting portion 5 together with a portion of the busbar 2. The resin molded portion 11 seals the fitting portion 5 by insert molding, and also seals the second extending portion 2b and the connecting portion 2c. It is preferable that the resin of the resin molded portion 11 also fills the gaps between the plurality of protrusions 5a. In this case, the spaces between the plurality of protrusions 5a are filled with resin, increasing the contact area, and high thermal conductivity can be obtained at the contact surface having the protrusions 5a.

[0027] As described above, the busbar 2 has a first extension portion 2a, a second extension portion 2b, and a connecting portion 2c, and has a partial U-shaped portion, and the first extension portion 2a, the connecting portion 2c, and the second extension portion 2b form three inner walls of the mounting space S. The bus bar 2 is made of a metal such as Cu. The bus bar module 1 of this embodiment is attached to the coil portion of the motor by welding or the like.

[0028] As described above, in the busbar temperature sensor 1 of this embodiment, the fitting portion 5 has a plurality of protrusions 5a formed on the surface that contacts one of the first extension portion 2a and the second extension portion 2b that faces the mounting space S. Therefore, when the fitting portion 5 is fitted into the mounting space S, the plurality of protrusions 5a are crushed to generate a biasing force, thereby stably maintaining the pressed-in state. As a result, the surface (heat-receiving surface) of the fitting portion 5 that contacts the other of the first extension portion 2a and the second extension portion 2b is at least reliably in close contact with the other of the first extension portion 2a and the second extension portion 2b, ensuring heat reception and enabling highly accurate temperature measurement.

[0029] Furthermore, the upper flange portion 5b can be engaged with the upper surfaces of the first extension portion 2a and the second extension portion 2b around the mounting space S, and the lower flange portion 5c can be engaged with the lower surfaces of the first extension portion 2a and the second extension portion 2b around the mounting space S. Therefore, the upper and lower flange structure prevents the temperature sensor 1 from coming loose in the vertical direction from the mounting space S and tilting, and also serves as a guide when fitting it into the mounting space S.

[0030] Furthermore, since the convex portion 5a is a protruding portion that extends in a direction perpendicular to the fitting direction into the mounting space S, the convex portion 5a of the protruding portion, which has a rib structure, can obtain high resistance to the force that tries to pull out in the direction opposite to the fitting direction by pressing in, thereby obtaining a high prevention effect against pulling out in the opposite direction. Furthermore, since a direction mark 5d indicating the direction of fitting into the mounting space S is displayed on the surface of the fitting portion 5, it can be attached to the bus bar 2 without making a mistake in the fitting direction.

[0031] Furthermore, the busbar module 10 of this embodiment includes a resin molded portion 11 that seals the fitting portion 5 together with a portion of the busbar 2, and therefore the fitting portion 5, which is stably held in a press-fit state by the multiple protrusions 5a, is further sealed with the resin molded portion 11 by injection molding (insert molding) or the like, thereby achieving even higher fixation, moisture resistance, impact resistance, and the like of the temperature sensor 1. Furthermore, heat from a portion of the busbar 2 can be transferred to the fitting portion 5 via the resin molded portion 11, allowing for more accurate temperature measurement. In particular, in the busbar module 10 of this embodiment, the busbar 2 is used in a motor stator, so the temperature of the motor stator can be measured with high accuracy and stability by the fitting portion 5 of the temperature sensor 1, to which the heat-receiving surface is securely in close contact.

[0032] Furthermore, since the resin molded portion 11 also seals the second extension portion 2b and the connecting portion 2c, the fitting portion 5 can be firmly sealed together with the surrounding second extension portion 2b and connecting portion 2c, and heat from the second extension portion 2b and connecting portion 2c can be transmitted to the fitting portion 5 via the resin molded portion 11, allowing the temperature to be measured with greater accuracy.

[0033] Next, a second embodiment of a busbar temperature sensor and a busbar module according to the present invention will be described below with reference to Figures 5 to 7. In the following description of the embodiment, the same components as those described in the above embodiment will be denoted by the same reference numerals, and their description will be omitted.

[0034] The difference between the second embodiment and the first embodiment is that in the first embodiment, the axis of the rectangular cylindrical case lower part 4a is arranged in a direction perpendicular to the fitting direction into the mounting space S and perpendicular to the extension direction of the first extension part 2a and the second extension part 2b (thickness direction of the busbar 2), whereas in the busbar temperature sensor 21 and busbar module 20 of the second embodiment, the axis of the rectangular cylindrical case lower part 24a is arranged in a direction along the fitting direction into the mounting space S, as shown in Figures 5 to 7.

[0035] That is, in the second embodiment, the case portion 24 extends along the extending direction of the first extending portion 2a of the bus bar 2. In FIG. 6, the bus bar 2 is hatched for ease of viewing. As described above, in the busbar temperature sensor 21 and busbar module 20 of the second embodiment, the case portion 24 extends along the extension direction of the first extension portion 2a of the busbar 2, so that the overall thickness can be reduced and the sensor can be installed in a narrow space.

[0036] Next, the third embodiment differs from the first embodiment in that, in the first embodiment, the upper flange portion 5b and the lower flange portion 5c are expanded in diameter over the entire circumference, whereas in the busbar temperature sensor 31 and busbar module of the third embodiment, as shown in Figures 8 and 9, the upper flange portion 5b and the lower flange portion 5c are expanded in diameter only on the surface side where the convex portion 35a is not formed.

[0037] That is, in the third embodiment, the upper flange portion 5b and the lower flange portion 5c are not enlarged in diameter on the surface side where the convex portion 35a is formed. The third embodiment is also different from the first embodiment in that the protruding portions 35a, which are protruding stripes, are cut off midway. That is, in the third embodiment, the convex portion 35a of the protruding portion extending along the axial direction is cut in the middle to form a concave portion in the middle.

[0038] In this way, in the busbar temperature sensor 31 of the third embodiment, the upper flange portion 5b and the lower flange portion 5c are expanded in diameter only on the surface side where the convex portion 35a is not formed, and are not expanded in diameter on the surface side where the convex portion 35a is formed. As a result, the upper flange portion 5b and the lower flange portion 5c do not get in the way during resin sealing using the resin molding portion, making it easier for resin to be filled between the convex portions 35a.

[0039] Therefore, when the resin of the resin molding part is filled into the gaps between the multiple protrusions 35a, the spaces between the multiple protrusions 35a are filled with resin, increasing the contact area, and high thermal conductivity can be obtained at the contact surface having the protrusions 35a. Furthermore, since the protrusions 35a, which are protruding portions, are cut halfway, resin is more easily filled between the protruding portions (protruding portions 35a) through the cut portions (recesses) during resin sealing by the resin molding portion.

[0040] The technical scope of the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

[0041] For example, although a chip thermistor is used in each of the above embodiments, a thin film thermistor or a pyroelectric element may also be used. Furthermore, as in the above embodiments, it is preferable to seal the bus bar temperature sensor in a resin molded portion and then finally fix it to the bus bar, but the bus bar temperature sensor may also be finally fixed to the bus bar using insulating varnish or the like. [Explanation of symbols]

[0042] 1, 21, 31... Busbar temperature sensor, 2... Busbar, 2a... First extension portion, 2b... Second extension portion, 2c... Connection portion, 3... Heat-sensitive element, 4, 24... Case portion, 5... Fitting portion, 5a, 35a... Convex portion, 5b, 35b... Upper flange portion, 5c, 35c... Lower flange portion, 5d... Direction mark, 10, 20... Busbar module, 11... Resin molded portion, S... Mounting space

Claims

1. A temperature sensor attached to a bus bar, A thermal element; a case portion in which the heat-sensitive element is housed, the bus bar includes a first extending portion, a second extending portion extending parallel to the first extending portion, and a connecting portion connecting the first extending portion and a tip end of the second extending portion, and has an attachment space between the first extending portion and the second extending portion which are opposed to each other; the case portion has a fitting portion that can be press-fitted into the mounting space, a plurality of protrusions are formed on a surface of the fitting portion that faces the mounting space and contacts one of the first extending portion and the second extending portion; the fitting portion has an upper flange portion and a lower flange portion whose diameter is larger than that of the mounting space, the upper flange portion can be engaged with upper surfaces of the first extension portion and the second extension portion around the mounting space, and the lower flange portion can be engaged with lower surfaces of the first extension portion and the second extension portion around the mounting space, The temperature sensor for a bus bar, wherein the upper flange portion and the lower flange portion serve as guides when fitting the temperature sensor into the mounting space.

2. 2. The bus bar temperature sensor according to claim 1, The temperature sensor for a bus bar, wherein the convex portion is a protruding portion extending in a direction perpendicular to the fitting direction into the mounting space.

3. 3. The bus bar temperature sensor according to claim 1, A temperature sensor for a bus bar, characterized in that a direction mark indicating the direction in which the fitting portion should be fitted into the mounting space is displayed on a surface of the fitting portion.

4. A bus bar and The bus bar temperature sensor according to claim 1 , which is attached to the bus bar; a resin molded portion that seals the fitting portion together with a portion of the bus bar.

5. The bus bar module according to claim 4, The bus bar module, wherein the resin molded portion also seals the second extension portion and the connecting portion.

6. The bus bar module according to claim 4 or 5, The bus bar module according to claim 1, wherein the lower flange portion and the upper flange portion have an expanded diameter only on the surface side where the protrusion is not formed.

7. 7. The busbar module according to claim 4, The bus bar temperature sensor is the bus bar temperature sensor according to claim 2, The bus bar module is characterized in that the protrusion portion is cut midway.

8. The bus bar module according to any one of claims 4 to 7, 10. A bus bar module, wherein the bus bar is used in a motor stator.

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