WO2018105610A1

WO2018105610A1 - Relay unit

Info

Publication number: WO2018105610A1
Application number: PCT/JP2017/043644
Authority: WO
Inventors: 徳貴池尻; 巧江島; 清史川口; 麻衣子小田; 健文鈴木; 芳和小原
Original assignee: トヨタ自動車株式会社; 住友電装株式会社
Priority date: 2016-12-05
Filing date: 2017-12-05
Publication date: 2018-06-14
Also published as: CN110024172B; CN110024172A

Abstract

This relay unit includes: a first bus bar; a relay electrically connected to the first bus bar; and an apparatus cover for covering the first bus bar and the relay. The apparatus cover includes: an upper member in a box shape having a covered upper end, said upper member having an opening formed in a lower end; and a lower member bonded to the upper member such that the opening of the upper member is covered with the lower member. The lower member is formed of a resin having heat conductivity that is higher than that of the upper member. The first bus bar is connected to the lower member via a first inner heat conductive sheet such that heat can be transferred to the lower member, said first inner heat conductive sheet being disposed between the first bus bar and the lower member.

Description

Relay unit

The present invention relates to a relay unit housed in a battery case.

In vehicles such as electric vehicles and hybrid vehicles, an electric motor for driving the vehicle is mounted. Moreover, a generator is mounted depending on the vehicle. Such a rotating electric machine that is an electric motor or a generator is connected to a battery via an inverter. At this time, a relay is connected between the inverter that is a load of the battery and the battery, and the relay is controlled by the control device, thereby switching an electrical connection state between the battery and the inverter.

Patent Document 1 describes a configuration in which a relay is housed in a vehicle, including other electrical components, inside an electrical housing. One end of the bus bar is electrically connected to the contact of the relay, and the other end of the bus bar is electrically connected to the output terminal of the battery block outside the electrical housing. Furthermore, the intermediate part of the bus bar is connected to the chassis constituting the vehicle via an insulating heat radiating sheet outside the electrical housing. Patent Document 1 also describes that the bus bar is not limited to the chassis and may be connected to a housing that houses the battery system. Thereby, it is supposed that the heat generated in the relay can be transferred to the chassis or another housing side to be dissipated.

JP 2014-79093 A

However, the position where the bus bar extended from the electrical housing and the chassis housing the chassis or the battery system are connected is far away from the heat generating contact inside the relay. As a result, the distance between the contact and the heat radiating portion of the relay is increased, which may make it difficult for the relay to radiate heat. For this reason, the cooling efficiency of a relay may fall.

An object of the present invention is to improve the cooling efficiency of a relay in a relay unit housed in a battery case.

The relay unit according to the present invention is a relay unit housed in a battery case, and includes a first bus bar, a relay electrically connected to the first bus bar, and a device that covers the first bus bar and the relay. A cover having an upper end closed, and an upper member formed with an opening at the lower end; and the upper cover connected to the upper member so as to close the opening of the upper member. A lower member, and the lower member is formed of a resin having higher heat conductivity than the upper member, and the first bus bar is disposed between the first bus bar and the lower member. The relay unit is connected to the lower member through the first inner heat conductive sheet so as to be able to transfer heat.

According to the relay unit according to the present invention, the first bus bar located in the device cover is connected to the lower member of the device cover so that heat can be transferred. Thereby, when the lower member is connected to the battery case so as to be capable of transferring heat, the distance from the relay contact to the battery case as the heat radiating portion can be easily reduced in the heat dissipation path of the relay. In addition, the battery case has a large heat capacity. This makes it easy to dissipate heat generated in the relay to a portion having a large heat capacity at a short distance, so that the cooling efficiency of the relay can be improved. Further, the first bus bar and the lower member are connected via the first inner heat conductive sheet. Thereby, even when the lower member is formed of a material that is easily cracked, the lower member can be prevented from colliding with the first bus bar due to vibration and cracking. Further, the lower member is formed of a resin having higher heat conductivity than the upper member. Thereby, since it is not necessary to make the heat conductivity of an upper member high, heat dissipation at the time of using the heat conduction path | route including a lower member can be improved, suppressing the cost of an apparatus cover.

In the relay unit according to the present invention, preferably, the relay unit includes an outer heat conductive sheet disposed below the lower member, and the first bus bar includes the first inner heat conductive sheet and the lower member. And is connected to the outer heat conductive sheet so as to be capable of transferring heat.

According to the preferable configuration described above, even when the battery case is connected to the lower side of the lower member of the device cover via the outer heat conductive sheet, It is possible to prevent the side member from colliding with the battery case due to vibration and cracking.

The relay unit according to the present invention preferably includes a second bus bar covered by the device cover, and the relay includes the first bus bar and the second bus bar between the first bus bar and the second bus bar. Two bus bars are electrically connected to each other, and a first recess and a second recess partitioned by an insulating wall are formed on the upper surface of the lower member, and the first inner heat conductive sheet is formed in the first recess. And the first bus bar is disposed on the upper side of the first inner heat conductive sheet in the first recess, the second inner heat conductive sheet is disposed in the second recess, and The second bus bar is disposed on the upper side of the second inner heat conductive sheet in the second recess, and the first bus bar is interposed between the first inner heat conductive sheet and the lower member. The second bus bar is connected to the outer heat conductive sheet through the second inner heat conductive sheet and the lower member so that heat can be transferred to the outer heat conductive sheet. Is done.

According to said preferable structure, the 1st inner side heat conductive sheet which contacts a 1st bus bar on the lower side, and the 2nd inner side heat conductive sheet which contacts a 2nd bus bar on the lower side are divided by the insulation wall. The first recess and the second recess are arranged separately. As a result, even if moisture enters the device cover or water vapor condenses inside the device cover and water accumulates at the lower end of the device cover, a short circuit outside the relay between the first bus bar and the second bus bar is prevented. Can be prevented.

In the relay unit according to the present invention, preferably, the outer heat conductive sheet is bonded to the lower surface of the lower member, and the outer peripheral surface of the outer heat conductive sheet is disposed on the lower surface of the lower member. A sheet protective wall protruding downward is formed at a portion facing at least a part of the sheet.

According to said preferable structure, an external thing or a person contacts an outer side heat conductive sheet at the time of conveyance of the relay unit containing an apparatus cover and an outer side heat conductive sheet, and an outer side heat conductive sheet peels from a lower member. Can be suppressed.

In the relay unit according to the present invention, preferably, the outer heat conductive sheet has a rectangular shape when viewed from one side in the thickness direction, and the sheet protection wall has a rectangular cross section so as to surround the outer heat conductive sheet. The height of the sheet protection wall is greater than the thickness of the outer heat conductive sheet.

According to the above preferable configuration, it is possible to further suppress the outer heat conductive sheet from being peeled from the cover lower member.

Also, in the relay unit according to the present invention, preferably, the sheet protection wall is formed with a notch so that a part in the circumferential direction is exposed on the outer peripheral surface including the lower end of the outer heat conductive sheet.

According to the above preferred configuration, when the relay unit including the device cover and the outer heat conductive sheet is transported, when the surface film is attached to the lower surface of the outer heat conductive sheet, the outer heat conduction is performed through the notch at the end of the transport. It becomes easy to remove the surface film from the sheet.

The relay unit according to the present invention can improve the cooling efficiency of the relay.

It is a circuit diagram which shows the vehicle-mounted battery relay connection structure of embodiment. In embodiment, it is sectional drawing which shows the battery module and apparatus cover which are arrange | positioned in the battery case. In embodiment, it is sectional drawing which shows the state in which the 1st bus bar in an apparatus cover was connected to the case lower side member which comprises a battery case. In another example of an embodiment, it is a sectional view showing the state where the 1st bus bar in a device cover was connected to the case lower side member which constitutes a battery case. In another example of an embodiment, it is a sectional view showing the state where the 1st bus bar in a device cover was connected to the case lower side member which constitutes a battery case. It is sectional drawing which takes out and shows the relay unit containing an apparatus cover and a relay from FIG. In another example of an embodiment, it is a sectional view showing the state where the 2nd bus bar in a device cover was connected to the case lower side member which constitutes a battery case. In the relay unit which comprises the battery relay connection structure of another example of embodiment, it is sectional drawing which shows the state from which the outer side heat conductive sheet peeled from the apparatus cover. It is sectional drawing which shows the relay unit which comprises the battery relay connection structure of another example of embodiment. It is the figure seen in the arrow A direction of FIG. In another example of an embodiment, it is a sectional view showing the state where the 1st bus bar and the 2nd bus bar in a device cover were connected to the case lower side member which constitutes a battery case. It is the B section enlarged view of FIG. In the relay unit which comprises the battery relay connection structure of another example of embodiment, it is the figure which abbreviate | omitted one part and looked from the lower side in the state which removed the cover lower side member of the apparatus cover. In the relay unit which comprises the battery relay connection structure of another example of embodiment, it is a perspective view which shows a part of 1st bus bar and 2nd bus bar arrange | positioned at the lower member of an apparatus cover.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The shape, material, and number described below are illustrative examples, and can be changed as appropriate according to the specifications of the vehicle including the in-vehicle battery relay connection structure. In the following description, identical elements are denoted by the same reference symbols in all drawings. In the description in the text, the symbols described before are used as necessary.

In the following, the case where the load of the battery is an inverter connected to the motor will be described. However, the embodiment is not limited to such a configuration, and the load may be another electrical component. .

FIG. 1 is a circuit diagram showing an in-vehicle battery relay connection structure 10 according to an embodiment. Hereinafter, the in-vehicle battery relay connection structure 10 is referred to as a battery relay connection structure 10. The battery relay connection structure 10 is mounted on a vehicle. The vehicle is an electric vehicle or a hybrid vehicle including a motor (not shown) that is a rotating electric machine as a drive source of the vehicle. When the vehicle is a hybrid vehicle, the vehicle includes an engine as a drive source in addition to the motor. A battery module 12, which is a battery, is connected to the motor via an inverter 50. The battery module 12 constitutes the battery relay connection structure 10. A positive relay 14 and a negative relay 15 are connected between the battery module 12 and the inverter 50.

Specifically, the battery relay connection structure 10 includes a battery module 12,

first bus bars

20a, 20b,

second bus bars

22a, 22b, a positive relay 14, a negative relay 15, a device cover 30, and a battery case 40. The battery module 12 is configured by electrically connecting a plurality of battery cells in series. The battery module 12 may include a configuration in which some battery cells are connected in parallel. The battery module 12 is accommodated in the battery case 40.

FIG. 2 is a cross-sectional view showing the battery module 12 and the device cover 30 arranged in the battery case 40 in the embodiment. The battery case 40 is configured by combining a case lower member 41 and a case upper member 45. The case lower member 41 includes a bottom plate portion 42 and an outer peripheral wall portion 43 erected from the outer peripheral edge of the bottom plate portion 42. The case upper member 45 includes a top plate portion 46 and an outer peripheral wall portion 47 that is connected to the outer peripheral edge of the top plate portion 46 and protrudes downward. The case upper member 45 is coupled to the case lower member 41 by fastening means (not shown) such as a bolt in a state where the case upper member 45 is fitted to the upper side of the case lower member 41 from the outside. Both the case upper member 45 and the case lower member 41 are formed of a metal such as iron or aluminum. For example, the case lower member 41 is formed by die casting of an aluminum alloy. Thereby, the heat dissipation of the case lower member 41 can be increased.

Inside the battery case 40, the battery module 12 and

first bus bars

20a and 20b,

second bus bars

22a and 22b, which will be described later, shown in FIGS. 1 and 3, a positive relay 14, a negative relay 15, and a device cover 30 are provided. Be contained. The device cover 30 covers the

first bus bars

20a, 20b, the

second bus bars

22a, 22b, the positive relay 14, and the negative relay 15, that is, covers from the outside.

As shown in FIG. 2, the battery module 12 is fixed on the bottom plate portion 42 of the case lower member 41 of the battery case 40. At this time, a plate-like heat insulating material 48 and a heat transfer member 49 are sequentially stacked on the upper side of the bottom plate portion 42, and the battery module 12 is disposed on the upper side of the heat transfer member 49. The heat transfer member 49 is configured by enclosing an endothermic gel, which is an endothermic agent as a refrigerant, in a container formed of an aluminum sheet. The heat transfer member 49 absorbs heat transferred from the battery module 12 to a part of the endothermic gel through the container, and diffuses and dissipates heat throughout the endothermic gel. Thereby, the heat insulation effect between the battery module 12 and the case lower member 41 by the heat insulating material 48 can be enhanced. The heat transfer member 49 disposed between the battery module 12 and the case lower member 41 can be omitted.

Further, with the battery case 40 fixed to the vehicle body (not shown), the bottom of the case lower member 41 of the battery case 40 is exposed to the outside of the vehicle. Thus, when the vehicle is traveling, the case lower member 41 can be cooled by the traveling wind flowing in the direction of the arrow α in FIG. Since the traveling wind is generally 60 ° C. or lower, the temperature of the battery case 40 that may be higher than 60 ° C. can be lowered by the traveling wind. The battery case 40 is not limited to the configuration in which the case lower member 41 is exposed to the outside of the vehicle. For example, the cooling air is supplied to the periphery of the battery case 40 through a duct by driving a blower motor or the like. It is good also as a structure to cool.

The device cover 30 is fixed on the upper side of the case lower member 41 of the battery case 40. The device cover 30 is called a junction BOX and is formed of a resin. The detailed structure of the device cover 30 will be described later with reference to FIG. Returning to FIG. 1, the first bus bars 20 a, 20 b, the second bus bars 22 a, 22 b, the positive relay 14 and the negative relay 15 are arranged inside the device cover 30. Each of the

relays

14 and 15 is configured by housing a relay body inside a relay case 16 made of an insulating material such as resin. The relay body includes two fixed contacts P1, P2, a movable piece R that can be brought into contact with and separated from the fixed contacts P1, P2, and an exciting coil (not shown) that switches a connection state between the movable piece R and the fixed contacts P1, P2. ). Two relay terminals T1 and T2 electrically connected to the fixed contacts P1 and P2 of the relay body are exposed outside the relay case 16 of each

relay

14 and 15.

Such positive and

negative relays

14 and 15 tend to generate heat in the vicinity of the internal fixed contacts P1 and P2. The internal contacts P1 and P2 are connected to relay terminals T1 and T2, and a bus bar described later is connected to the relay terminals T1 and T2. Therefore, in the embodiment, the cooling performance of the

relays

14 and 15 is improved by facilitating heat dissipation in portions of the bus bar close to the relay terminals T1 and T2 as described later.

Specifically, in the positive relay 14 and the negative relay 15, one end of the

first bus bars

20a and 20b is connected to the relay terminal T1 on the battery module 12 side. The other ends of the first bus bars 20 a and 20 b are connected to battery-side connector terminals T 3 and T 4 attached to the device cover 30. The battery-side connector terminal T3 connected to the positive relay 14 and the positive output terminal Tp of the battery module 12 are connected by a wire line L1 through the service plug SP.

The battery-side connector terminal T4 connected to the negative relay 15 and the negative output terminal Tn of the battery module 12 are connected by a wire line L2. Thereby, the positive electrode output terminal Tp of the battery module 12 and the first bus bar 20a are electrically connected, and the negative electrode output terminal Tn of the battery module 12 and the first bus bar 20b are electrically connected. The service plug SP is configured so that the power supply circuit can be manually opened and closed by inserting and removing the grip with respect to the housing.

In the positive relay 14 and the negative relay 15, one end of the

second bus bars

22a and 22b is connected to the relay terminal T2 on the inverter 50 side. The other ends of the

second bus bars

22a and 22b are connected to inverter-side connector terminals T5 and T6 attached to the device cover 30. A part of the device cover 30 is integrally attached to the case lower member 41 (FIG. 1) of the battery case 40, and the two inverter-side connector terminals T5 and T6 are located under the case through the integrated part. It is exposed to the outside of the side member 41. The two inverter-side connector terminals T5 and T6 are connected to the positive electrode input terminal T7 and the negative electrode input terminal T8 of the inverter 50 arranged away from the battery case 40 by two wire lines L3 and L4. Thereby, the positive electrode input terminal T7 of the inverter 50 and the second bus bar 22a are electrically connected, and the negative electrode input terminal T8 of the inverter 50 and the second bus bar 22b are electrically connected.

Each of the

relays

14 and 15 switches the electrical connection state between the battery module 12 and the inverter 50 by switching between energization and stopping of the excitation coil of the relay body. Such switching of the

relays

14 and 15 is controlled by a control device (not shown).

Next, the heat dissipation structure of the

relays

14 and 15 using the

bus bars

20a, 20b, 22a, and 22b will be described with reference to FIG. FIG. 3 is a cross-sectional view showing a state in which the first bus bar 20a in the device cover 30 is connected to the case lower member 41 constituting the battery case 40 in the embodiment. FIG. 3 shows only the first bus bar 20a connected to the positive relay 14 among the four

bus bars

20a, 20b, 22a, and 22b shown in FIG. Below, the positive electrode relay 14 may be described as the relay 14.

The device cover 30 has a substantially box shape with the upper end closed, and an opening is formed at the lower end. An outward flange 31 is formed around the opening at the lower end of the device cover 30. In the battery case 40, the flange 31 of the device cover 30 is overlaid on the bottom plate portion 42 of the case lower member 41. In this state, the screw portion of the bolt 32 fixed to the case lower member 41 passes through the flange 31 upward, and the nut 33 is coupled to the screw portion protruding from the upper surface of the flange 31. Thereby, the apparatus cover 30 is fixed to the case lower member 41. A projecting portion 35 that projects inward is formed on the lower surface of the top plate portion 34 positioned at the upper end of the device cover 30, and a bus bar holding claw 35 a is formed at the lower end portion thereof. For example, the bus bar holding claw 35a is bent at a right angle at the lower end and engages and holds the first bus bar 20a on the upper side thereof.

The relay case 16 is fixed to the lower surface of the top plate portion 34 of the device cover 30. Further, the relay terminal T1 of the relay body protrudes from one side surface of the relay case 16 in the lateral direction (left side surface in FIG. 3). Then, one end of the first bus bar 20a is connected to the relay terminal T1 outside the one lateral side surface of the relay case 16. The intermediate portion of the first bus bar 20a passes through the lower side of the relay case 16 in the lateral direction (left-right direction in FIG. 3) and is led out to the other lateral side of the relay case 16 (right side in FIG. 3). The other end portion of the first bus bar 20 a is held by a bus bar holding claw 35 a formed on the device cover 30, and the other end portion of the first bus bar 20 a is a battery side connector terminal T 3 (exposed to the outside of the device cover 30). 1). One end of a wire L1 (FIG. 1) electrically connected to the battery module 12 is connected to the battery-side connector terminal T3 outside the device cover 30.

The intermediate portion of the first bus bar 20a is sandwiched between the lower side surface of the relay case 16 and the upper side surface of the case lower member 41 of the battery case 40 via two insulating heat

conductive sheets

36 and 37 on both upper and lower sides. It is. The lower heat conductive sheet 37 corresponds to an inner heat conductive sheet. Thereby, the intermediate part of the 1st bus-bar 20a is connected to the relay case 16 via the upper heat conductive sheet 36 so that heat transfer is possible. Further, the intermediate portion of the first bus bar 20a is connected to the case lower member 41 through the lower heat conductive sheet 37 so that heat can be transferred. The upper heat conductive sheet 36 between the intermediate portion of the first bus bar 20a and the relay case 16 may be omitted, and the intermediate portion of the first bus bar 20a may directly contact the lower surface of the relay case 16. This also enables heat to be transferred from the relay case 16 to the intermediate portion of the first bus bar 20a. Further, in this specification, “connected so that heat can be transferred” means that two members are connected through one or more members having heat transfer properties, and that the two members are in direct contact to transfer heat. Including the meaning of

In the above-described battery relay connection structure 10, the heat generated at the contact inside the relay 14, as indicated by the broken line arrow in FIG. 3, the contact inside the relay → the relay terminal T 1 → the first bus bar 20 a → the lower heat conduction. As in the case of the sheet 37 → the case lower member 41, a heat dissipation path that is sequentially transmitted is formed. Then, the heat transmitted to the case lower member 41 is transmitted (dissipated) to the outside air. As described above, the first bus bar 20a located in the device cover 30 is connected to the battery case 40 so as to be able to transfer heat. Therefore, in the heat dissipation path of the relay 14, the case lower member 41 as a heat dissipation portion from the contact of the relay 14 is used. It is easy to reduce the distance. The case lower member 41 is larger than the device cover 30 and has a larger heat capacity. This makes it easy to dissipate the heat generated in the relay 14 to a portion having a large heat capacity at a short distance, so that the cooling efficiency of the relay 14 can be improved.

On the other hand, in the case of the configuration described in Patent Document 1, the middle portion of the bus bar connected to the relay accommodates the chassis or battery system that constitutes the vehicle outside the electrical housing corresponding to the device cover. Connected to the housing. In the case of this configuration, the distance of the heat radiation path from the relay to the portion having a large heat capacity tends to be large. This makes it difficult to increase the cooling efficiency of the relay.

Furthermore, according to the embodiment, since the heat is transmitted from the relay case 16 to the first bus bar 20a via the upper heat conductive sheet 36 or directly, the cooling efficiency of the relay 14 can be further increased.

Further, the device cover 30 is fastened to the case lower member 41 by fastening means including bolts and nuts, so that the heat conductive sheet is interposed between the relay case 16 and the case lower member 41 via the first bus bar 20a. 36 and 37 can also be compressed. Thereby, since the heat

conductive sheets

36 and 37 can be brought into contact with each other between the relay case 16, the first bus bar 20 a, and the case lower member 41 with high adhesion, heat conductivity can be further increased.

In FIG. 3 described above, only the heat dissipation structure including the first bus bar 20a connected to the positive relay 14 among the four

bus bars

20a, 20b, 22a, and 22b illustrated in FIG. 1 has been described. The heat dissipation structure is similarly configured for 20b, 22a, and 22b. At this time, one end of the second bus bar 22a (FIG. 1) can be connected to a relay terminal protruding to the other side in the horizontal direction of the positive relay 14 (right side in FIG. 3). In this case, the intermediate portion of the second bus bar 22a is passed under the relay case 16, and the other end portion of the second bus bar 22a is opposite to the other end portion of the first bus bar 20a (see FIG. 3 (left side of 3). Thereby, all the bus bars connected to the positive electrode relay 14 and the negative electrode relay 15 are connected to the case lower member 41 of the battery case 40 so that heat can be transferred. Note that only one of the first bus bar and the second bus bar can be connected to the case lower member 41 so as to be able to transfer heat.

FIG. 4 is a cross-sectional view showing a state in which the first bus bar 20a in the device cover 30 is connected to the case lower member 41 constituting the battery case 40 in another example of the embodiment. In the configuration of another example shown in FIG. 4, in the configuration shown in FIGS. 1 to 3, the device cover 30 includes a cover lower member 38 arranged so as to close the opening at the lower end. The cover lower member 38 is formed in a plate shape from a resin having high heat conductivity. The intermediate portion of the

first bus bars

20a, 20b is sandwiched between the relay case 16 and the cover lower member 38 via the two

heat conduction sheets

36, 37 on the upper and lower sides. Furthermore, the second heat conductive sheet 39 made of an insulating material such as resin is sandwiched between the lower side surface of the cover lower side member 38 and the case lower side member 41 of the battery case 40. The second heat conductive sheet 39 corresponds to an outer heat conductive sheet. As a result, the heat generated at the contact inside the relay 14 is, as indicated by the broken arrow in FIG. 4, the contact inside the relay → the relay terminal T1 → the first bus bar 20a → the lower heat conductive sheet 37 → the lower side of the cover. It is transmitted in the order of the member 38 → the second heat conductive sheet 39 → the case lower member 41. Then, the heat transmitted to the case lower member 41 is transmitted (dissipated) to the outside air.

According to the above configuration, the resin lower cover member 38 and the second heat conductive sheet 39 made of an insulating material are disposed between the case lower member 41 and the first bus bar 20a, so the first bus bar 20a. And the case lower member 41 can be further improved in insulation. In the case of the configuration of FIG. 4 as well, the heat conductive sheet 36 on the upper side of the first bus bar 20a may be omitted as in the configurations of FIGS. 4, only the heat dissipation structure including the first bus bar 20a connected to the positive relay 14 among the four

bus bars

20a, 20b, 22a, and 22b illustrated in FIG. 1 has been described. The heat dissipation structure is similarly configured for 22a and 22b. Further, only one of the first bus bar and the second bus bar can be connected to the case lower member 41 so that heat can be transferred. Other configurations and operations are the same as those in FIGS. 1 to 3.

FIG. 5 is a cross-sectional view showing a state where the first bus bar 20a in the device cover 60 is connected to a case lower member 41a constituting the battery case 40a in another example of the embodiment. 6 is a cross-sectional view showing the relay unit 13 including the device cover 60 and the positive relay 14 taken out from FIG. FIG. 7 is a cross-sectional view showing a state where the second bus bar 22a in the device cover 60 is connected to the case lower member 41a.

In the configuration of this example, the battery case 40a constituting the battery relay connection structure is configured such that the case upper member 45 is overlapped and coupled to the upper surface of the flat case lower member 41a. Specifically, the case lower member 41a is formed of a metal such as iron or aluminum in the same manner as the configurations of the above examples. The case lower member 41a has a substantially rectangular shape when viewed from above, and an outer peripheral wall portion 51 is formed on the outer peripheral edge of the upper surface over the entire periphery. A recess 52 is formed inside the outer peripheral wall 51 on the upper surface of the case lower member 41a. Furthermore, a protrusion 53 having a rectangular cross section is formed to protrude from a plurality of positions on the bottom surface of the recess 52. Each protrusion 53 is formed so as to face the lower side of the device cover 60 of each of the positive electrode relay 14 and the negative electrode relay 15 (FIG. 1). The entire outer peripheral surface of each protrusion 53 is surrounded by the recess 52. As will be described later, each protrusion 53 is pressed against the cover lower member 61 constituting the device cover 60 via the outer heat conductive sheet 65. The case upper member 45 is superposed on the upper surface of the outer peripheral wall portion 51 of the case lower member 41a and is coupled by fastening means (not shown) such as a bolt. Thereby, the battery case 40a forms a waterproof structure by blocking the internal space from the outside.

The positive and negative relay units 13 are fixed inside the battery case 40a. Since the configuration of the negative relay unit is the same as that of the positive relay unit 13, the positive relay unit 13 will be described below. As shown in FIGS. 6 and 7, the relay unit 13 includes a device cover 60, a positive relay 14 disposed inside the device cover 60, a first bus bar 20 a, a second bus bar 22 a, and a first inner heat conductive sheet 66. The second inner heat conductive sheet 67 and the outer heat conductive sheet 65 are included.

The device cover 60 is configured by combining a cover upper member 62 and a cover lower member 61. The cover upper member 62 has a substantially box shape with the upper end closed by the top plate portion 63, and an opening is formed at the lower end. The cover lower member 61 has a substantially flat plate shape and is coupled to the cover upper member 62 by fastening means (not shown) such as a bolt so as to close the opening at the lower end of the cover upper member 62.

The cover upper member 62 is made of an insulating resin. On the other hand, the cover lower member 61 is made of a resin having higher heat conductivity than the cover upper member 62. For example, the cover lower member 61 is preferably formed of a resin having a thermal conductivity that is five times or more that of the resin forming the cover upper member 62. For example, the thermal conductivity of the resin forming the cover upper member 62 is about 0.2 W / mK, and the thermal conductivity of the resin forming the cover lower member 61 is 1.0 to 3.5 W / mK. . Thereby, since it is not necessary to make the heat conductivity of the cover upper member 62 high, it is possible to improve heat dissipation when the heat conduction path including the cover lower member 61 is used while suppressing the cost of the device cover 60. For example, the cover lower member 61 can be made of a nylon resin filled with a filler to increase the thermal conductivity. Further, polybutylene terephthalate resin (PBT) can be used as a material for forming the cover upper member 62. The cover upper member 62 is coupled to the case lower member 41a of the battery case 40a by a fastening member (not shown) such as a bolt penetrating a flange (not shown) formed on the outer peripheral portion of the lower end.

As in the configuration of each example shown in FIGS. 3 and 4 above, one end of the first bus bar 20a is outside the longitudinal side surface of the relay case 16 (the left side surface in FIGS. 5 and 6), and the relay terminal Connected to T1. The intermediate portion of the first bus bar 20a in the longitudinal direction passes through the lower side of the relay case 16 in the longitudinal direction of the relay case (left and right direction in FIGS. 5 and 6), and the other longitudinal side of the relay case (in FIGS. 5 and 6). To the right). The other end portion of the first bus bar 20 a is coupled to the top plate portion 63 of the cover upper member 62 together with one end portion of an intermediate bus bar (not shown) on the other longitudinal side of the relay case 16. The other end of the intermediate bus bar is connected to a battery-side connector terminal T3 (FIG. 1) that is exposed to the outside of the device cover 60.

On the other hand, as shown in FIG. 7, one end of the second bus bar 22a is connected to the relay terminal T2 outside the one longitudinal side surface (the left side surface in FIG. 7) of the relay case 16. The middle portion in the longitudinal direction of the second bus bar 22a enters the lower side of the relay case 16 and extends in the width direction perpendicular to the longitudinal direction on the lower side of the relay case (the front and back direction in FIG. 7). It is derived | led-out to the width direction one side (back side of the paper surface of FIG. 7). The other end of the second bus bar 22a is connected to the inverter-side connector terminal T5 (FIG. 1) exposed on the outside of the device cover 60 on one side in the width direction of the relay case 16. Thus, the positive relay 14 is electrically connected to each of the first bus bar 20a and the second bus bar 22a between the first bus bar 20a and the second bus bar 22a.

5 and 6, the first inner heat conductive sheet 66 is an insulating resin sheet having high heat conductivity, and is sandwiched between the lower end surface of the first bus bar 20 a and the cover lower member 61. . The first inner heat conductive sheet 66 is preferably formed from a non-silicone resin material. Thereby, even when the temperature of the first inner heat conductive sheet 66 rises during use, no siloxane gas is generated, so that it is possible to prevent relay contact failure due to the siloxane gas.

As shown in FIG. 7, the second inner heat conductive sheet 67 is an insulating resin sheet having high heat conductivity, and is sandwiched between the lower end surface of the second bus bar 22 a and the cover lower member 61. Similarly to the first inner heat conductive sheet 66, the second inner heat conductive sheet 67 is preferably formed from a non-silicone resin material. Each of the first inner heat conductive sheet 66 and the second inner heat conductive sheet 66 has a lower surface hardness than the cover lower member 61. The first inner heat conductive sheet 66 and the second inner heat conductive sheet 67 may be formed using, for example, a low-hardness acrylic resin. The first inner heat conductive sheet 66 and the second inner heat conductive sheet 67 are arranged apart from each other.

The outer heat conductive sheet 65 is a resin sheet having high heat conductivity, and is sandwiched between the upper surface of the protrusion 53 formed on the case lower member 41a of the battery case 40a and the cover lower member 61. The outer heat conductive sheet 65 has a rectangular shape when viewed from one side in the thickness direction. The outer heat conductive sheet 65 has substantially the same size as the outer shape of the upper surface of the protrusion 53 of the case lower member 41a, for example. The outer heat conductive sheet 65 has a lower surface hardness than the cover lower member 61. For example, the outer heat conductive sheet 65 may be formed of the same material as each of the inner heat

conductive sheets

66 and 67 described above.

Further, when the battery case 40a and the relay unit 13 are viewed from the lower side, the outer heat conductive sheet 65 is at least partly a first inner heat conductive sheet 66 and a second inner heat conductive sheet 67, and a cover lower member. 61 are arranged so as to overlap with each other. The cover lower member 61 is not in direct contact with the case lower member 41 a and is connected to the case lower member 41 a via the outer heat conductive sheet 65. At this time, the protrusion 53 of the case lower member 41 a is pressed against the cover lower member 61 via the outer heat conductive sheet 65. As shown in FIG. 6, the outer heat conductive sheet 65 is bonded to the lower surface of the cover lower member 61 to form the relay unit 13. Accordingly, the first bus bar 20a is connected to the outer heat conductive sheet 65 through the first inner heat conductive sheet 66 and the cover lower member 61 so as to be able to transfer heat. The second bus bar 22a is connected to the outer heat conductive sheet 65 through the second inner heat conductive sheet 67 and the cover lower member 61 so as to be able to transfer heat.

Therefore, the first bus bar 20a is connected to the cover lower member 61 via the first inner heat conductive sheet 66 so as to be able to transfer heat, and the outer heat conductive sheet which is another lower member from the cover lower member 61. 65 and heat transfer to the battery case 40a. At the same time, the second bus bar 22a is connected to the cover lower member 61 via the second inner heat conductive sheet 67 so as to be able to transfer heat, and from the cover lower member 61 to the outer heat conductive sheet 65 and the battery case 40a. Heat transfer is possible.

According to the above configuration, the heat generated at the contact inside the positive relay 14 is transmitted to the case lower member 41a as shown by the broken line arrow in FIG. Specifically, the heat is sequentially applied in the order of contact in the relay → relay terminal T1 → first bus bar 20a → first inner heat conductive sheet 66 → cover lower member 61 → outer heat conductive sheet 65 → case lower member 41a. Is transmitted. Further, as indicated by broken line arrows in FIG. 7, the contact inside the relay → the relay terminal T2 → the second bus bar 22a → the second inner heat conductive sheet 67 → the cover lower member 61 → the outer heat conductive sheet 65 → the case lower member. As in 41a, heat is transferred in order. The heat transmitted to the case lower member 41a is transmitted to the outside air (dissipated), so that the heat of the relay can be released.

Furthermore, according to the relay unit 13 described above, when the cover lower member 61 is connected to the battery case 40a so that heat can be transferred, from the relay contact to the battery case 40a as the heat radiating portion in the heat dissipation path of the relay. Easy to reduce the distance. Further, the battery case 40a has a large heat capacity. This makes it easy to dissipate heat generated in the relay to a portion having a large heat capacity at a short distance, so that the cooling efficiency of the relay can be improved. Further, the first bus bar 20a and the second bus bar 22a and the cover lower member 61 are connected via the first inner heat conductive sheet 66 or the second inner heat conductive sheet 67 so as to be able to transfer heat. Thereby, even when the cover lower member 61 is formed of a material that is easily broken, it is possible to prevent the cover lower member 61 from colliding with the first bus bar 20a and the second bus bar 22a by vibration and cracking. Further, the first bus bar 20a and the second bus bar 22a are connected to the outer heat conductive sheet 65 via the first inner heat conductive sheet or the second inner heat conductive sheet 67 and the cover lower member so as to be able to transfer heat. As a result, the battery case 40 a is connected to the lower side of the cover lower member 61 via the first inner heat conductive sheet or the second inner heat conductive sheet 67. In this case, even when the cover lower member 61 is formed of a material that is easily broken, the cover lower member 61 can be prevented from colliding with the battery case 40a due to vibration and cracking. In this example, other configurations and operations are the same as the configurations in FIGS. 1 to 3 or the configuration in FIG. 4.

In the configuration shown in FIGS. 5 to 7, one inner heat conductive sheet can be used in common instead of the first inner heat conductive sheet 66 and the second inner heat conductive sheet 67. The heat transmitted to the first bus bar 20a and the second bus bar 22a is transmitted to the case lower member 41a through the heat dissipation path including the inner heat conductive sheet.

FIG. 8 is a cross-sectional view showing a state in which the outer heat conductive sheet 65 is peeled off from the device cover 60 in the relay unit 13 constituting the battery relay connection structure of another example of the embodiment. In FIG. 8, illustration of the first bus bar, the second bus bar, the first inner heat conductive sheet, and the second inner heat conductive sheet is omitted. Similar to the configuration of FIG. 6, an outer heat conductive sheet 65 is bonded to the lower surface of the cover lower member 61. In such a configuration, when the relay unit 13 is transported to a place where the relay unit 13 is assembled to the battery case, an external object or a person comes into contact with the outer heat conductive sheet 65 unexpectedly and a force is applied to the outer heat conductive sheet 65. there is a possibility. As a result, the outer heat conductive sheet 65 may be peeled off from the cover lower member 61. Further, when the moving member moves in a state where the relay unit 13 is disposed on the moving member (not shown), the device cover 60 of the relay unit 13 vibrates, and the outer heat conductive sheet 65 becomes the cover lower member. There is also a possibility that the position slips with respect to 61.

Furthermore, if foreign matter such as dust adheres to the surface of the outer heat conductive sheet 65, the heat transfer performance of the outer heat conductive sheet 65 may be reduced. In order to prevent the deterioration of the heat conduction performance, it is conceivable to attach a surface film to the lower surface of the outer heat conduction sheet 65. This surface film is removed before the relay unit 13 is assembled to the battery case 40a (FIG. 5). For this reason, it is necessary to facilitate the removal of the surface film.

Next, another example of the embodiment described with reference to FIGS. 9 and 10 has been invented to improve such a point. FIG. 9 is a cross-sectional view showing a relay unit 13a constituting another example of the embodiment. FIG. 10 is a diagram viewed in the direction of arrow A in FIG. In FIG. 9, as in FIG. 8, the first bus bar, the second bus bar, the first inner heat conductive sheet, and the second inner heat conductive sheet are not shown.

In the configuration of this example, the outer heat conductive sheet 65 is bonded to the lower surface of the cover lower member 61a constituting the device cover 60a. Further, on the lower surface of the cover lower member 61a, a sheet protective wall 70 protruding downward is formed at a portion facing at least a part of the outer peripheral surface of the outer heat conductive sheet 65. The sheet protection wall 70 is formed in a cylindrical shape having a substantially rectangular cross section so as to surround the outer heat conductive sheet 65. The height of the sheet protection wall 70 is larger than the thickness of the outer heat conductive sheet 65.

Furthermore, a notch 71 is formed in a part of the sheet protective wall 70 in the circumferential direction and facing a part of the outer peripheral surface of the outer heat conductive sheet 65 over the entire length in the height direction of the sheet protective wall 70. Is done. Thereby, the notch 71 is formed so that a part in the circumferential direction is exposed on the outer peripheral surface including the lower end of the outer heat conductive sheet 65.

In addition, a surface film (not shown) is attached to the lower surface of the outer heat conductive sheet 65 to prevent foreign matter from adhering to the lower surface during transport of the relay unit 13a. The surface film is removed before the relay unit 13a is assembled to the battery case.

According to the above-described configuration, the sheet protective wall 70 protruding downward is formed on the lower surface of the cover lower member 61a at a portion facing at least a part of the outer peripheral surface of the outer heat conductive sheet 65. Thereby, at the time of conveyance of the relay unit 13a, it can suppress that an external thing or a person contacts an outer side heat conductive sheet, and the outer side heat conductive sheet 65 peels from the cover lower side member 61a.

Further, the sheet protection wall 70 is formed in a cylindrical shape having a substantially rectangular cross section so as to surround the outer heat conductive sheet 65 on the lower surface of the cover lower member 61a. It is larger than the thickness of the conductive sheet 65. Thereby, it can suppress more that the outer side heat conductive sheet 65 peels from the cover lower side member 61a.

Furthermore, a cutout 71 is formed in the sheet protection wall 70 so that a part in the circumferential direction is exposed on the outer peripheral surface including the lower end of the outer heat conductive sheet 65. Thereby, when the surface film is affixed to the lower surface of the outer heat conductive sheet 65 during the transport of the relay unit 13a, the surface film can be easily removed from the outer heat conductive sheet 65 through the notch 71 at the end of the transport. The operator removes the surface film. For example, the operator can easily remove the surface film from the outer heat conductive sheet 65 by attaching an adhesive tape to the lower surface of the surface film through the notch 71. In addition, the operator can easily remove the surface film from the outer heat conductive sheet 65 by causing the finger to enter the inside of the sheet protective wall 70 through the notch 71 and hooking the finger on the surface film sticking side. Other configurations and operations are the same as those in FIGS. 1 to 3, 4, or 5 to 7.

FIG. 11 is a cross-sectional view showing a state where the first bus bar 20a and the second bus bar 22a in the device cover 60b are connected to the case lower member 41b constituting the battery case 40b in another example of the embodiment. FIG. 12 is an enlarged view of a portion B in FIG. FIG. 13 is a view of the relay unit 13b constituting the battery relay connection structure as seen from below with a part omitted, with the cover lower member 61b (FIG. 12) of the device cover removed. FIG. 14 is a perspective view showing a part of the first bus bar 20a and the second bus bar 22a arranged in the cover lower member 61b in the relay unit 13b.

In the configuration of this example, as shown in FIGS. 11 and 12, the battery case 40b is formed by connecting the case upper member 45a and the case lower member 41b with a bolt 72. A device cover 60b forming the relay unit 13b is fixed to the case lower member 41b. The device cover 60b is formed by connecting the cover upper member 62a and the cover lower member 61b. The positive relay 14 is fixed to the cover upper member 62a inside the device cover 60b.

As shown in FIG. 13, the longitudinal intermediate portions of the first bus bar 20a and the second bus bar 22a are arranged in the width direction of the relay case 16 (up and down in FIG. 13) on the lower side of the positive relay 14 (the front side of the paper surface of FIG. 13). Are arranged side by side. In the longitudinal intermediate portion of the first bus bar 20a, a protrusion 21 protruding to one side in the width direction of the relay case 16 (the lower side in FIG. 13) is formed at a portion disposed below the relay case 16. . 11 and 12 correspond to the CC cross section of FIG. The protrusion 21 is arranged in a longitudinally intermediate portion of the second bus bar 22a on the lower side of the relay case 16 and in the longitudinal direction of the relay case 16 (left and right directions in FIGS. 11, 12, and 13). Be placed. The first bus bar 20a and the second bus bar 22a are arranged apart from each other. As shown in FIG. 13, the other end portion (the right end portion in FIG. 13) of the first bus bar 20a is the other side in the width direction of the relay case 16 (the upper side in FIG. 13), together with an intermediate bus bar (not shown). Screwed to the upper member 62a. The other end (the lower end in FIG. 13) of the second bus bar 22a is screwed to the cover upper member 62a on one side in the width direction of the relay case 16 (the lower side in FIG. 13) and is connected to the inverter side connector terminal T5. (Fig. 1).

Furthermore, as shown in FIGS. 12 and 14, a first recess 74 and a second recess 75 partitioned by an insulating wall 73 are formed on the upper surface of the cover lower member 61b constituting the device cover 60b. The insulating wall 73 is a double wall and is formed by two

wall portions

73a and 73b. Corresponding to the L-shaped gap 80 between the first bus bar 20a and the second bus bar 22a shown in FIG. 13, each of the

wall portions

73a and 73b is L-shaped when viewed from above, with a gap therebetween. Formed side by side. As a result, a concave portion 73c at the intermediate portion in the width direction is formed in the insulating wall 73 over the entire length.

As shown in FIG. 12, a first inner heat conductive sheet 66 is disposed at the lower end of the first recess 74. In addition, a flat plate-shaped intermediate portion located at the lower end of the first bus bar 20a is disposed on the upper side of the first inner heat conductive sheet 66 in the first recess 74 so as to overlap therewith. At the same time, a second inner heat conductive sheet 67 is disposed at the lower end of the second recess 75. In addition, a flat plate-like middle portion in the longitudinal direction located at the lower end of the second bus bar 22a is overlaid on the upper side of the second inner heat conductive sheet 67 in the second recess 75. As shown in FIG. 13, the first inner heat conductive sheet 66 is L-shaped, and the second inner heat conductive sheet 67 is rectangular.

Further, on the lower side of the lower cover member 61b (FIG. 12), when viewed from one side in the vertical direction, as shown in FIG. The outer heat conductive sheet 65 is bonded by bonding.

According to the above configuration, the first inner heat conductive sheet 66 that contacts the first bus bar 20a on the lower side and the second inner heat conductive sheet 67 that contacts the second bus bar 22a on the lower side are separated by the insulating wall 73. The first concave portion 74 and the second concave portion 75 are divided and arranged. As a result, even when water enters the device cover 60b or water vapor condenses inside the device cover 60b and water accumulates at the lower end of the device cover 60b, the relay between the first bus bar 20a and the second bus bar 22a. Can prevent a short circuit outside. Other configurations and operations are the same as those in FIGS. 1 to 3, FIG. 4, or FIGS. 5 to 7.

In each of the above examples, the case where the

first bus bars

20a and 20b are electrically connected to the output terminal of the battery module 12 and the

second bus bars

22a and 22b are electrically connected to the input terminal of the load has been described. . On the other hand, the first bus bar may be electrically connected to the input terminal of the load, and the second bus bar may be electrically connected to the output terminal of the battery. Further, in each of the above examples, the case where at least one of the first bus bar and the second bus bar is connected to the case lower member 41 of the battery case 40 so as to be able to transfer heat has been described. On the other hand, the one bus bar may be connected to the case upper member of the battery case so that heat can be transferred. In this case, for example, the lower end of the device cover is closed and an opening is provided at the upper end, and the one bus bar is connected to the case upper member via the heat conductive sheet in the device cover. 5 to 14, the

relay units

13, 13a, 13b have been described as including the outer heat conductive sheet 65. However, the relay unit may not include the outer heat conductive sheet. For example, the outer heat conductive sheet can be provided on the relay unit side in the battery case.

10 battery relay connection structure for vehicle (battery relay connection structure), 12 battery module, 13, 13a, 13b relay unit, 14 positive relay, 15 negative relay, 16 relay case, 20a, 20b first bus bar, 21 protrusion, 22a , 22b 2nd bus bar, 30 equipment cover, 31 flange, 32 bolt, 33 nut, 34 top plate part, 35 projecting part, 35a bus bar holding claw, 36 heat conduction sheet, 37 heat conduction sheet, 38, 38a cover lower member 39, second heat conductive sheet, 40, 40a, 40b battery case, 41, 41a, 41b lower case member, 42 bottom plate, 43 outer peripheral wall, 45, 45a upper case member, 46 top plate, 47 outer peripheral wall Part, 48 heat insulating material, 49 heat transfer member, 50 50, 60a, 60b equipment cover, 61, 61a, 61b cover lower member, 62, 62a cover upper member, 63 top plate part, 65 outer heat conduction sheet, 66 1st inner heat conductive sheet, 67 2nd inner heat conductive sheet, 70 sheet protective wall, 71 notch, 72 bolt, 73 insulating wall, 73a, 73b wall part, 73c recessed part, 74 1st recessed part, 75 2nd recessed part, 80 gap.

Claims

A relay unit housed in a battery case,
The first bus bar,
A relay electrically connected to the first bus bar;
A device cover covering the first bus bar and the relay;
With
The device cover has a box shape with an upper end closed, and includes an upper member having an opening formed at the lower end, and a lower member coupled to the upper member so as to close the opening of the upper member. And
The lower member is formed of a resin having higher heat transfer than the upper member,
The first bus bar is a relay unit that is connected to the lower member through a first inner heat conductive sheet disposed between the first bus bar and the lower member so as to be able to transfer heat.
The relay unit according to claim 1,
Including an outer heat conductive sheet disposed on the lower side of the lower member,
The first bus bar is a relay unit that is connected to the outer heat conductive sheet through the first inner heat conductive sheet and the lower member so as to be able to transfer heat.
The relay unit according to claim 2,
A second bus bar covered by the device cover;
The relay is electrically connected to each of the first bus bar and the second bus bar between the first bus bar and the second bus bar,
A first recess and a second recess partitioned by an insulating wall are formed on the upper surface of the lower member,
The first inner heat conductive sheet is disposed in the first recess, and the first bus bar is disposed on the upper side of the first inner heat conductive sheet in the first recess.
A second inner heat conductive sheet is disposed in the second recess, and the second bus bar is disposed on the upper side of the second inner heat conductive sheet in the second recess;
The first bus bar is connected to the outer heat conductive sheet via the first inner heat conductive sheet and the lower member so as to be able to transfer heat, and the second bus bar is connected to the second inner heat conductive sheet. A relay unit connected to the outer heat conductive sheet via a conductive sheet and the lower member so as to be capable of transferring heat.
The relay unit according to claim 2,
The outer heat conductive sheet is bonded to the lower surface of the lower member,
A relay unit, wherein a sheet protection wall protruding downward is formed on a lower surface of the lower member at a portion facing at least a part of the outer peripheral surface of the outer heat conductive sheet.
The relay unit according to claim 4,
The outer heat conductive sheet is rectangular when viewed from one side in the thickness direction,
The sheet protection wall is formed in a rectangular cross section so as to surround the outer heat conductive sheet,
The height of the sheet protection wall is a relay unit larger than the thickness of the outer heat conductive sheet.
The relay unit according to claim 4,
A relay unit in which a cutout is formed in the sheet protection wall so that a part in the circumferential direction is exposed on an outer peripheral surface including a lower end of the outer heat conductive sheet.