Busbar module with temperature sensor

Abstract

To provide a temperature sensor and bus bar module including the temperature sensor that can alleviate an impact of a spray of coolant and the like.SOLUTION: A temperature sensor 1, which is provided in a heating body 2, comprises: a case part 3 that is provided in a part of the heating body, and has at least an outer peripheral face other than a face 1a contacting with the heating body formed of resin; and a sensor main body 4 that is housed inside the case part. The case part includes: a sensor housing part 5 that houses the sensor main body; a resin sealing part 6 that seals the sensor main body in the sensor housing part; and an insulation layer 7 that is provided between the peripheral face other than the face contacting with the heating body and the sensor housing part, and has at least a cavity part.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a temperature sensor that is provided on a heating element such as a bus bar used as a wiring member for a motor, a battery, or an automobile, and a bus bar module equipped with the same. [Background technology]

[0002] 2. Description of the Related Art Bus bars used as wiring members for motors, batteries, and automobiles are known to have temperature sensors attached thereto in order to detect the temperature of the bus bars. For example, a temperature sensor is provided on a bus bar of a coil conductor in order to detect the temperature of the coil conductor of a motor stator.

[0003] Since the motor stator becomes hot, a structure is adopted in which it is cooled by spraying a refrigerant such as ATF (Automatic Transmission Fluid), but if the refrigerant is sprayed directly onto the temperature sensor, the temperature sensor itself will be cooled and the temperature of the coil conductor cannot be measured accurately. For this reason, as described in Patent Documents 1 to 3, a cover has been attached to the temperature sensor to prevent it from being affected by the refrigerant. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2012-175861 A [Patent Document 2] JP 2012-223085 A [Patent Document 3] JP 2018-121422 A Summary of the Invention [Problem to be solved by the invention]

[0005] The above conventional techniques still have the following problems. That is, in the above-mentioned conventional technology, a cover is attached to the temperature sensor, but when refrigerant is sprayed onto the cover, the internal temperature sensor is also cooled to some extent through the cover, again resulting in a problem of reduced temperature measurement accuracy. In addition, when a cover is attached to the temperature sensor, the work of attaching the cover is required and the entire temperature sensor including the cover becomes larger, which is disadvantageous in terms of size. Furthermore, when a cover is simply attached, the only cooling method available is spraying, which is a problem of poor cooling efficiency.

[0006] The present invention has been made in consideration of the above-mentioned problems, and has an object to provide a temperature sensor and a bus bar module including the same that can reduce external influences such as coolant spray. [Means for solving the problem]

[0007] The present invention employs the following configuration to solve the above problems. That is, the temperature sensor according to the first invention is a temperature sensor provided on a heating element, comprising: a case portion provided on a part of the heating element and having an outer circumferential surface formed of resin other than the contact surface with the heating element; and a sensor main body housed in the case portion, the case portion comprising a sensor housing portion for housing the sensor main body, a resin sealing portion for sealing the sensor main body in the sensor housing portion, and a heat insulating layer having at least a cavity portion provided between the outer circumferential surface other than the contact surface with the heating element and the sensor housing portion.

[0008] In other words, this temperature sensor has an insulating layer having at least a hollow portion disposed between the outer surface other than the contact surface with the heating element and the sensor storage section, and therefore the insulating effect of the insulating layer having a hollow portion can suppress the effects of temperature changes outside the outer surface other than the contact surface with the heating element (temperature measurement surface), thereby improving the temperature measurement accuracy. Furthermore, since a heat insulating layer is provided inside the case, there is no need to provide a separate large cover, which not only eliminates the need for cover attachment work, but also provides an advantage in terms of the overall dimensions of the temperature sensor. Furthermore, since the cooling method for the motor stator and the like can be impregnation in addition to spraying, it is possible to improve the cooling efficiency.

[0009] The temperature sensor according to a second invention is the temperature sensor according to the first invention, characterized in that the heat insulating layer is an air layer that is entirely hollow. That is, in this temperature sensor, the heat insulating layer is an air layer that is entirely hollow, and therefore a high heat insulating effect can be obtained by the heat insulating layer that is entirely air.

[0010] A temperature sensor according to a third invention is the temperature sensor according to the first invention, characterized in that the heat insulating layer is a foamed material layer formed of a foamed material having a plurality of cavities. In other words, in this temperature sensor, the insulating layer is a foamed material layer formed from a foamed material having multiple cavities, so that it is possible to obtain the insulating effect provided by the multiple cavities and the effect of maintaining the strength of the insulating layer by the foamed material.

[0011] The temperature sensor of the fourth invention is characterized in that, in any of the first to third inventions, the case portion has a high thermal conductivity material portion on the contact surface, the high thermal conductivity material portion having a higher thermal conductivity than the resin of the outer peripheral surface other than the contact surface with the heating element. In other words, in this temperature sensor, the case portion is provided with a highly thermally conductive material portion on its contact surface which has higher thermal conductivity than the resin on the outer peripheral surface other than the contact surface with the heating element, so that the heat received on the contact surface by the highly thermally conductive material portion can be effectively transferred to the sensor body.

[0012] A busbar module according to a fifth aspect of the present invention is characterized by comprising a busbar and a temperature sensor according to any one of the first to fourth aspects of the present invention provided on the busbar, which is the heating element. This busbar module is equipped with a temperature sensor of any one of the first to fourth inventions provided on the busbar, which is a heating element, so that the temperature of the busbar can be accurately measured by the temperature sensor, which is less susceptible to external influences and has high temperature measurement accuracy.

[0013] A busbar module according to a sixth aspect of the present invention is characterized in that, in the fifth aspect, the busbar has a rectangular cross section, the case portion includes a case body having the contact surface in contact with one surface of the outer periphery of the busbar, and claw portions arranged on the surface of the busbar opposite the contact surface, and the busbar is removably attached by being sandwiched between the case portion and the claw portions. That is, in this bus bar module, the case portion is detachably attached by clamping the bus bar between the case portion and the claw portion, so that the temperature sensor can be easily detachably attached to the bus bar.

[0014] The busbar module according to a seventh aspect of the present invention is characterized in that, in the fifth aspect, the busbar is U-shaped and includes a first extension portion, a second extension portion extending parallel to the first extension portion, and a connecting portion connecting an end portion of the first extension portion and an end portion of the second extension portion, and the case portion is provided between the first extension portion and the second extension portion with the contact surfaces in contact with opposing surfaces of the first extension portion and the second extension portion. In other words, in this busbar module, the case portion is provided between the first extension portion and the second extension portion by injection molding or the like, with the contact surfaces in contact with the opposing surfaces of the first extension portion and the second extension portion, so that the heat of the busbar can be more effectively transferred to the sensor body by the two contact surfaces arranged on both sides of the sensor body. Effect of the Invention

[0015] According to the present invention, the following effects are obtained. In other words, the temperature sensor of the present invention is provided with an insulating layer having at least a hollow portion that is provided between the outer surface other than the contact surface with the heating element and the sensor storage section, so that the insulating effect of the insulating layer having a hollow portion can suppress the effects of temperature changes outside the outer surface other than the contact surface with the heating element (temperature measurement surface), thereby improving the temperature measurement accuracy. Therefore, a bus bar module equipped with a temperature sensor of the present invention can achieve improved bus bar temperature measurement accuracy, simplified installation work, overall size reduction, and improved cooling efficiency, making it suitable as a bus bar module for motor stators, etc. [Brief description of the drawings]

[0016] [Figure 1] 2 is a cross-sectional view (a cross-sectional view taken along line AA in FIG. 2) showing a first embodiment of a temperature sensor and a bus bar module including the same according to the present invention. [Diagram 2] FIG. 2 is a perspective view showing a bus bar module in the first embodiment. [Diagram 3] 5 is a cross-sectional view (cross-sectional view taken along line BB in FIG. 4) showing a second embodiment of the temperature sensor and the bus bar module including the same according to the present invention. FIG. [Figure 4] FIG. 11 is a perspective view showing a bus bar module in a second embodiment. [Diagram 5] 11A is a perspective view showing a state before a sensor body is sealed in a third embodiment of a temperature sensor and a bus bar module including the same according to the present invention, FIG. 11B is a side view, and FIG. 11C is a perspective view showing a case portion. [Figure 6] 13A is a perspective view showing a state before a sensor body is sealed in a fourth embodiment of a temperature sensor and a bus bar module including the same according to the present invention, FIG. 13B is a side view, and FIG. 13C is a perspective view showing a case portion. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] A first embodiment of a temperature sensor and a busbar module including the same according to the present invention will be described below with reference to Figures 1 and 2. Note that in some of the drawings used in the following description, the scale has been appropriately changed as necessary to make each part recognizable or easily recognizable.

[0018] The temperature sensor 1 of this embodiment is a temperature sensor provided on a heating element 2 (bus bar) as shown in Figures 1 and 2, and includes a case portion 3 provided on a part of the heating element 2 and having an outer peripheral surface made of resin other than at least a contact surface 1a with the heating element 2, and a sensor main body 4 housed in the case portion 3. The outer peripheral surface of the case portion 3, including the contact surface 1a, is made of resin. The heating element 2 is made of a metal such as Cu, and is, for example, a coil conductor of a motor stator, or a bus bar connected to a coil end portion (hereinafter, also referred to as bus bar 2).

[0019] The case portion 3 includes a sensor storage portion 5 for storing the sensor main body 4, a resin sealing portion 6 for sealing the sensor main body 4 within the sensor storage portion 5, and an insulating layer 7 having at least a hollow portion and provided between the sensor storage portion 5 and the outer peripheral surface other than the contact surface 1a with the heating element 2. The heat insulating layer 7 in this embodiment is an air layer that is entirely hollow. The heat insulating layer 7 is formed in a U-shape in cross section so as to surround the outer circumferential surface of the sensor housing portion 5, which is rectangular in cross section, except for the contact surface 1a.

[0020] Moreover, the bus bar module 10 of this embodiment includes the bus bar 2 which is a heating element, and the temperature sensor 1 provided on the bus bar 2. The bus bar 2 is a flat wire having a rectangular cross section, and is made of a metal such as Cu. The case portion 3 includes a case main body 3a having a contact surface 1a in contact with one surface of the outer circumferential surface of the busbar 2, and two claw portions 3b extending in an L-shaped cross section from the lower portion of the case main body 3a to the opposite surface 2b of the busbar 2 relative to the contact surface 1a.

[0021] The claw portion 3b has a protrusion at its tip that can be engaged with a corner portion of the opposite surface 2b of the busbar 2. In this manner, the case portion 3 is detachably attached by sandwiching the bus bar 2 between the case portion 3 and the claw portions 3b. That is, the bus bar 2 is fitted between the case portion 3 and the claw portion 3b in a snap-fit ​​manner.

[0022] The sensor body 4 includes a heat-sensitive element (not shown) such as a chip thermistor, a sealing glass portion (not shown) that covers the heat-sensitive element with glass, a resin coated portion 4a that covers the sealing glass portion with resin, and a pair of lead wires 8 whose ends are connected to the heat-sensitive element. The resin coating portion 4a is formed so as to cover the connection portion between the pair of lead wires 8 and the heat sensitive element. The pair of lead wires 8 extend and protrude from the resin sealing portion 6 to the outside. For the resin sealing portion 6, a casting insulating resin such as silicone resin or epoxy resin can be used, and in particular, a resin having better thermal conductivity than the case portion 3 is preferable.

[0023] As described above, the temperature sensor 1 of this embodiment is provided with an insulating layer 7 having at least a hollow portion and disposed between the outer peripheral surface other than the contact surface 1a with the heating element 2 and the sensor storage section 5. Therefore, the insulating effect of the insulating layer 7 having a hollow portion can suppress the influence of temperature changes outside the outer peripheral surface other than the contact surface with the heating element 2 (temperature measurement surface), thereby improving the temperature measurement accuracy. Furthermore, since the heat insulating layer 7 is provided inside the case portion 3, there is no need to provide a separate large cover, which not only eliminates the need for cover attachment work, but also provides an advantage in terms of the overall dimensions of the temperature sensor.

[0024] Furthermore, since the cooling method for the motor stator and the like can be impregnation in addition to spraying, it is possible to improve the cooling efficiency. Furthermore, since the heat insulating layer 7 is an air layer that is entirely hollow, a high heat insulating effect can be obtained by the heat insulating layer 7 that is entirely air.

[0025] Therefore, since the busbar module 10 of this embodiment is equipped with the above-mentioned temperature sensor 1 provided on the busbar 2, which is a heating element, it is possible to accurately measure the temperature of the busbar 2 by the temperature sensor 1, which is less susceptible to external influences and has high temperature measurement accuracy. Furthermore, since the case portion 3 is detachably attached by sandwiching the bus bar 2 between the case portion 3 and the claw portions 3b, the temperature sensor 1 can be easily detachably attached to the bus bar 2.

[0026] Next, second to fourth embodiments of the busbar module according to the present invention will be described below with reference to Fig. 3 to Fig. 6. In the following description of each embodiment, the same components as those described in the above embodiments are denoted by the same reference numerals, and the description thereof will be omitted.

[0027] The difference between the second embodiment and the first embodiment is that the temperature sensor 1 of the first embodiment has a case portion 3 having one contact surface 1a, whereas the temperature sensor 21 and busbar module 20 of the second embodiment have a case portion 23 having two contact surfaces 21a, as shown in Figures 3 and 4. The second embodiment also differs from the first embodiment in that the case portion 23 is insert-molded into the bus bar 22, which is a heating element, by injection molding.

[0028] That is, the busbar 22 is U-shaped and has a first extension portion 22a, a second extension portion 22b extending parallel to the first extension portion 22a, and a connecting portion 22c connecting the tip end of the first extension portion 22a and the tip end of the second extension portion 22b. Further, the case portion 23 is molded between the first extension portion 22a and the second extension portion 22b with the contact surfaces 21a in contact with the opposing surfaces of the first extension portion 22a and the second extension portion 22b.

[0029] Moreover, the heat insulating layer 27 is a foam material layer formed of a foam material having a plurality of cavities. The plurality of cavities in the heat insulating layer 27 are a large number of voids (air bubbles) in the foam material. As the foam material, for example, a porous material such as foamed resin or foamed metal having a network structure can be used. The heat insulating layers 27 of the second embodiment are disposed between the sensor body 4 and the outer peripheral surfaces (upper and lower surfaces) other than the contact surfaces 21a disposed on both sides of the sensor body 4 facing each other, that is, above and below the sensor body 4.

[0030] Furthermore, case portion 23 includes, on each of two contact surfaces 21a, highly heat-conductive material portions 29 having higher thermal conductivity than the resin on the outer peripheral surface other than contact surface 21a with bus bar 22, which is a heat generating body. As the highly heat-conductive material portion 29, for example, a metal plate or metal foil made of SUS, aluminum, or the like can be used. The case portion 23 includes two side frame portions 23b through which the first extending portion 22a and the second extending portion 22b are inserted, and a front end frame portion 23a through which the connecting portion 22c is inserted.

[0031] In the method of manufacturing the temperature sensor 21 and the bus bar module 20 of this embodiment, as described above, first, the case portion 23 is integrally molded with the bus bar 22 by injection molding. At this time, in the case portion 23, a sensor storage portion 25 for storing the sensor main body 4, and two cavities for the high thermal conductive material portion 29 above and below the sensor cavity portion 25 are simultaneously formed. Next, the two cavities for the highly thermally conductive material portion 29 are filled with a foam material to form the highly thermally conductive material portion 29 . Furthermore, the sensor body 4 is inserted into the sensor storage section 25, and a metal plate or the like which is a highly thermally conductive material section 20 is placed on the two contact surfaces 21a, and then resin is filled in and sealed to form a resin sealing section 6, thereby producing the temperature sensor 21 and the bus bar module 20.

[0032] As described above, in the temperature sensor 21 of this embodiment, the insulating layer 27 is a foamed material layer formed of a foamed material having a plurality of cavities, and therefore, it is possible to obtain the insulating effect due to the plurality of cavities and the effect of maintaining the strength of the insulating layer due to the foamed material. In addition, since the case portion 23 is provided on the contact surface 21a with a high thermal conductivity material portion 29 which has a higher thermal conductivity than the resin of the outer peripheral surface other than the contact surface 21a with the bus bar 22, which is the heating element, the heat received at the contact surface 21a can be more effectively transferred by the high thermal conductivity material portion 29 to the sensor main body 4.

[0033] Furthermore, in the busbar module 20 of this embodiment, the case portion 23 is provided by injection molding between the first extension portion 22a and the second extension portion 22b with the contact surfaces 21a in contact with the opposing surfaces of the first extension portion 22a and the second extension portion 22b, so that the heat of the busbar 22 can be more effectively transferred to the sensor main body 4 by the two contact surfaces 21a arranged on both sides of the sensor main body 4.

[0034] Next, the third embodiment differs from the first embodiment in that, whereas in the temperature sensor 1 and busbar module 10 of the first embodiment, the busbar 2 is attached by snap-fitting into the case portion 3, the temperature sensor and busbar module of the third embodiment are produced by inserting the busbar 32 into a pre-formed case portion 33, as shown in FIG. 5. 5(c), in the third embodiment, case portion 33 having frame portion 33a and tip locking portion 33b is molded in advance from resin so that bus bar 32 can be inserted therein. Then, case portion 33 is attached to bus bar 32 by inserting U-shaped bus bar 32 into frame portion 33a and abutting the connecting portion of bus bar 32 against tip locking portion 33b.

[0035] In this state, the space between the opposing inner faces of the bus bars 32 forms a sensor storage portion 35 . In addition, in the case 33, hollow heat insulating layers 37 are provided above and below the sensor storage portion . In the sensor storage portion 35 of the case portion 33 into which the bus bar 32 is thus inserted, the sensor main body 4 is inserted and filled with resin to form a resin sealing portion. The openings of the two heat insulating layers 37 are closed with lids.

[0036] Next, the difference between the fourth embodiment and the third embodiment is that while the temperature sensor and busbar module of the third embodiment is fabricated by inserting the busbar 32 into the frame portion 33a of the case portion 33, the temperature sensor and busbar module of the fourth embodiment is fabricated by fitting a pre-formed case portion 43 inside the U-shaped busbar 32, as shown in FIG. 6.

[0037] That is, in the fourth embodiment, as shown in FIG. 6(c), a box-shaped case portion 43 is formed in advance from resin, and this case portion 43 is attached to the bus bar 32 by fitting the case portion 43 inside the U-shaped bus bar 32. In the case 43, a sensor storage section 45 and hollow heat insulating layers 47 are provided above and below the sensor storage section 45 in advance. In the sensor housing portion 45 of the case portion 43 thus fitted inside the U-shaped bus bar 32, the sensor main body 4 is inserted and filled with resin to form a resin sealing portion. The openings of the two heat insulating layers 47 are closed with lids.

[0038] 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.

[0039] For example, in each of the above embodiments, a chip thermistor is used as the heat-sensitive element of the sensor body, but a flake-type thermistor, a thin-film thermistor, a pyroelectric element, or the like may also be used. In addition, in each of the above embodiments, the case portion is attached to or insert-molded on the U-shaped bus bar, but the case portion may be attached to or insert-molded on a bus bar having another shape. [Explanation of symbols]

[0040] Reference Signs List 1, 21...Temperature sensor, 1a, 21a...Contact surface, 2, 22, 32...Bus bar (heat generating element), 3...Case portion, 3a...Case body, 3b...Claw portion, 4...Sensor body, 5...Sensor storage portion, 6...Resin sealing portion, 7...Heat insulating layer, 10, 20...Bus bar module, 22a...First extension portion, 22b...Second extension portion, 22c...Connecting portion, 29...Highly heat conductive material portion

Claims

1. A bus bar, a temperature sensor provided on the bus bar, the bus bar being a heating element; The temperature sensor, a case portion provided on a part of the heat generating element and having an outer peripheral surface made of resin other than a surface that comes into contact with the heat generating element; a sensor body housed in the case portion, The case portion has a sensor housing portion for housing the sensor main body, a resin sealing portion that seals the sensor main body within the sensor storage portion; a heat insulating layer having at least a cavity provided between the sensor housing and an outer peripheral surface other than a contact surface with the heat generating body, The bus bar has a rectangular cross section, a case body having a contact surface in contact with one surface of the outer circumferential surface of the bus bar, and a claw portion arranged on the surface of the bus bar opposite the contact surface, and the bus bar is removably attached by being sandwiched between the case body and the claw portion.

2. A bus bar, a temperature sensor provided on the bus bar, the bus bar being a heating element; The temperature sensor, a case portion provided on a part of the heat generating element and having an outer peripheral surface made of resin other than a surface that comes into contact with the heat generating element; a sensor body housed in the case portion, The case portion has a sensor housing portion for housing the sensor main body, a resin sealing portion that seals the sensor main body within the sensor storage portion; a heat insulating layer having at least a cavity provided between the sensor housing and an outer peripheral surface other than a contact surface with the heat generating body, The bus bar includes a first extension portion and A second extension portion extending parallel to the first extension portion; The first extension portion and the second extension portion are connected to each other by a connecting portion. a case portion disposed between the first extension portion and the second extension portion with the contact surfaces in contact with the opposing surfaces of the first extension portion and the second extension portion,

3. The bus bar module according to claim 1 or 2, A bus bar module, wherein the heat insulating layer is an air layer that is entirely hollow.

4. The bus bar module according to claim 1 or 2, The bus bar module according to claim 1, wherein the insulating layer is a foam material layer formed of a foam material having a plurality of cavities.

5. The bus bar module according to claim 1 or 2, A busbar module, characterized in that the case portion has a high thermal conductivity material portion on the contact surface which has higher thermal conductivity than the resin on the outer peripheral surface other than the contact surface with the heating element.

Images