Patent ID: 12240395

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

First, embodiments of the present disclosure will be listed and described.

An electrical junction box according to the present disclosure is as follows.

First Aspect

In a first aspect, an electrical junction box including: a bus bar; a frame that holds the bus bar; and a temperature detection member that detects the temperature of the bus bar, wherein the temperature detection member includes a detection main body part capable of detecting temperature, and a wiring part extending from the detection main body part, and is held by one or more holding parts, the frame is integrally molded in a shape including a frame part surrounding a periphery of at least a part of the bus bar that includes a detection target portion to be subjected to detection by the temperature detection member, and at least one holding part of the one or more holding parts, and the at least one holding part of the one or more holding parts is provided so as to be located inward of the frame part. Since the holding part that holds the temperature detection member is integrally molded with the frame that holds the bus bar, it is possible to hold the temperature detection member while keeping the number of components as low as possible.

Second Aspect

In a second aspect, one or more holding parts may include a proximal end portion holding part that holds a proximal end portion of the wiring part that extends continuously with the detection main body part. With this configuration, the detection main body part that is located close to the proximal end portion holding part is stabilized.

Third Aspect

In a third aspect, the temperature detection member may further include a thermal connection member that thermally connects the detection main body part and the bus bar to each other, and the one or more holding parts may include a connection portion holding part that holds a portion where the thermal connection member and the bus bar are thermally connected to each other. With this configuration, the thermal connection portion is further held.

Fourth Aspect

In a fourth aspect, a hole may be formed in each of the thermal connection member and the bus bar, each of the thermal connection member and the bus bar may be fixed by a bolt and a nut using the hole, the connection portion holding part may have a support surface that supports the bus bar, a recess may be formed in the support surface, and the nut may fit in the recess. This configuration allows the connection portion holding part to hold the nut.

Fifth Aspect

In a fifth aspect, the holding force of the connection portion holding part may be greater than the holding force of the proximal end portion holding part. The proximal end portion holding part is more likely to rattle than the connection portion holding part, and thus stress is less likely to be applied to the connection portion holding part

Sixth Aspect

In a sixth aspect, the thermal connection member may be supported by an upper surface of the bus bar at the connection portion holding part, and may be supported by a support surface of the proximal end portion holding part at the proximal end portion holding part, and the height of the support surface of the proximal end portion holding part may be lower than the height of the upper surface of the bus bar at the connection portion holding part. With this configuration, the bus bar and the thermal connection member easily come into surface contact with each other at the connection portion.

Seventh Aspect

In a seventh aspect, one or more holding parts may include a proximal end-side intermediate portion holding part that holds an intermediate portion of the wiring part, the proximal end-side intermediate portion holding part may be provided at a position next to the proximal end portion holding part in order from the proximal end portion toward a distal end portion along a direction in which the wiring part extends, and the holding force at the proximal end-side intermediate portion holding part may be weaker than the holding force of the proximal end portion holding part and the holding force of the connection portion holding part. With this configuration, the proximal end-side intermediate portion holding part is more likely to rattle than the connection portion holding part and the proximal end portion holding part, and thus stress is less likely to be applied to the proximal end portion holding part and the connection portion holding part.

Eighth Aspect

In an eighth aspect, one or more holding parts may include a first intermediate holding part and a second intermediate holding part that hold an intermediate portion of the wiring part at positions different from each other, a first groove that traverses a rib protruding from the frame part may be formed in the first intermediate holding part, a second groove parallel to the rib may be formed in the second intermediate holding part, the second groove may be formed to be longer than the first groove, and the intermediate portion of the wiring part may be accommodated in each of the first groove and the second groove. With this configuration, an excess length of the wiring part is absorbed by the second intermediate holding part.

Ninth Aspect

In a ninth aspect, the second intermediate holding part may be provided with a retaining piece protruding from an edge portion of an opening of the second groove so as to close the opening. With this configuration, the wiring part is prevented from being dislodged from the second groove that is longer than the first groove.

Tenth Aspect

In a tenth aspect, the first groove and the second groove may be open in directions opposite to each other. With this configuration, the wiring part is held at the first intermediate holding part and the second intermediate holding part from sides opposite to each other.

Eleventh Aspect

In an eleventh aspect, the electrical junction box may further include a circuit board to which a distal end portion of the wiring part is to be electrically connected, wherein the frame may include a first frame that supports the bus bar, and a second frame that supports the circuit board and that presses the bus bar toward the first frame, a positioning projection that positions the circuit board may be formed inward of the frame part of the second frame, and the rib in which the first groove is formed may extend from a circuit board supporting part on which the positioning projection is formed. With this configuration, the wiring part is held at a position close to the positioning projection.

Twelfth Aspect

In a twelfth aspect, the holding force at the first intermediate holding part may be weaker than a force holding the wiring part at an electrical connection portion between the wiring part and the circuit board. Stress is less likely to be applied to the electrical connection portion.

Specific examples of the electrical junction box according to the present disclosure will be described below with reference to the drawings. It should be noted that the present disclosure is not limited to these examples, but is defined by the claims, and is intended to include all modifications which fall within the scope of the claims and the meaning and scope of equivalents thereof.

Embodiment 1

Below, an electrical junction box according to Embodiment 1 will be described.FIG.1is an exploded perspective view showing an electrical junction box10according to Embodiment 1.FIG.2is an exploded perspective view showing the electrical junction box10according to Embodiment 1.FIG.3is a plan view showing the electrical junction box10according to Embodiment 1.FIG.4is a schematic cross-sectional view taken along the line IV-IV inFIG.3.

The electrical junction box10is mounted in a vehicle. The electrical junction box10is provided at an intermediate position of an electric circuit that connects a power supply (e.g., a main battery) and a first load (e.g., a headlamp or a wiper) to each other. A second load (e.g., a starter) is directly connected to the power supply. The electrical junction box10interrupts the connection between the power supply and the first load when a large current flows from the power supply to the second load, thereby protecting the first load from the adverse effects of a large current. Specifically, the electrical junction box10includes a bus bar20, a frame30, and a temperature detection member50. The electrical junction box10further includes switching elements60, a circuit board70, a cover80, a heat dissipation member82, and an interposed member84. Here, as the switching elements60, a plurality of field-effect transistors (FETs: Field Effect Transistors) are provided. Here, the frame30is placed on the heat dissipation member82. In the following, the direction in which the frame30is placed on the heat dissipation member82(the up-down direction inFIG.1) will be referred as the up-down direction. The up-down direction may or may not coincide with a vertical direction in a state in which the electrical junction box10is mounted in the vehicle.

The bus bar20is connected to a plurality of field-effect transistors60. The bus bar20includes a first bus bar21, a second bus bar25, and third bus bars28. The first bus bar21, the second bus bar25, and the third bus bars28are insulated from each other. Each field-effect transistor60includes a drain terminal62, a source terminal63, and a gate terminal64. The first bus bar21is electrically connected to the drain terminals62. The second bus bar25is electrically connected to the source terminals63. The third bus bars28are electrically connected to the gate terminals64, respectively.

Specifically, the first bus bar21is a conductive plate such as a metal plate formed in a bent shape. The first bus bar21includes an in-frame accommodating part22and an outward extending part23. The in-frame accommodating part22is a portion that is surrounded by frame parts32and41, which will be described later. The in-frame accommodating part22includes a placement portion22aand a detection target portion22b. A main body61of each field-effect transistor60is placed on the placement portion22a. The drain terminal62is provided at a lower portion of the main body61of the field-effect transistor60. The first bus bar21is electrically connected to a plurality of drain terminals62on the placement portion22a. The detection target portion22bcomes into contact with the temperature detection member50. The detection target portion22bis located on the upper side of the placement portion22a. The detection target portion22bextends continuously with the placement portion22avia a rising portion. A through hole22his formed in the detection target portion22b. The outward extending part23is a portion that extends outward of the frame parts32and41. The outward extending part23is electrically connected to an external conductor at an external connection part39, which will be described later. The outward extending part23is located on the upper side of the placement portion22aand the detection target portion22b. The outward extending part23extends continuously with the placement portion22avia a rising portion. An insertion hole23hfor passing a stud bolt SB therethrough is formed in the outward extending part23.

The second bus bar25is a plate-shaped conductor formed in a bent shape. The second bus bar25includes an in-frame accommodating part26and an outward extending part27. The in-frame accommodating part26is a portion that is surrounded by the frame parts32and41. The source terminals63are placed on a portion of the in-frame accommodating part26. The second bus bar25is electrically connected to a plurality of source terminals63in the in-frame accommodating part26. The outward extending part27is a portion that extends outward of the frame parts32and41. The outward extending part27is electrically connected an external conductor at the external connection part39. The outward extending part27is located on the upper side of the in-frame accommodating part26. The outward extending part27extends continuously with the in-frame accommodating part26via a rising portion. An insertion hole27hfor passing a stud bolt SB therethrough is formed in the outward extending part27.

Each third bus bar28is formed in a bar shape. The third bus bar28connects the field-effect transistor60and the circuit board70to each other. The third bus bars28are provided in a number corresponding to the number of field-effect transistors60. One end portion of the third bus bar28is connected to the gate terminal64. The other end portion of the third bus bar28is connected to the circuit board70. As a member that connects the gate terminal64and the circuit board70to each other, a flexible wire such as a coated wire may be used in place of the third bus bar28.

The frame30holds the bus bar20. The frame30includes a first frame31and a second frame40. The frame30is made of, for example, an insulating material such as a resin.

The first frame31supports the bus bar20. The first frame31includes a frame part32, a bus bar supporting part33, and a connection portion holding part38. The first frame31is an integrally molded article that has been integrally molded in a shape including the frame part32, the bus bar supporting part33, and the connection portion holding part38.

The frame part32is formed in a tubular shape that is open at the top and the bottom. The frame part32surrounds the periphery of at least a portion of the bus bar20that includes the detection target portion22bthat is to be subjected to detection by the temperature detection member50. Here, the frame part32surrounds the periphery of the in-frame accommodating parts22and26. The bus bar supporting part33is provided inward of the frame part32.

The bus bar supporting part33includes a partition part34, and a first bus bar supporting part35and a second bus bar supporting part36. The partition part34separates the first bus bar21and the second bus bar25from each other so as to prevent a short circuit from occurring between the first bus bar21and the second bus bar25. The first bus bar supporting part35and the second bus bar supporting part36protrude inward from edges of the partition part34and the frame part32. The first bus bar supporting part35and the second bus bar supporting part36are formed to have a thickness that is smaller than that of the partition part34. The first bus bar supporting part35and the second bus bar supporting part36protrude from the lower surface side of the partition part34and the frame part32. The first bus bar supporting part35protrudes in a cantilevered manner from the partition part34, and supports edges of the first bus bar21. A portion of the second bus bar supporting part36protrudes in a cantilevered manner from the partition part34, and supports edges of the second bus bar25. Another portion of the second bus bar supporting part36connects the partition part34and the frame part32to each other, and supports the entire second bus bar25in a partial region thereof along the width direction. In a state in which the first bus bar21and the second bus bar25are supported by the first bus bar supporting part35and the second bus bar supporting part36, the upper surfaces of the in-frame accommodating parts22and26other than the detection target portion22bare located at about the same height as the upper surface of the partition part34.

The bus bar supporting part33further includes third bus bar supporting parts37. The third bus bar supporting parts37support the third bus bars28so as to prevent a short circuit from occurring between the third bus bars28and the first bus bar21and the second bus bar25. The third bus bar supporting parts37are formed adjacent to the partition part34. The third bus bar supporting parts37are formed at the same height as the partition part34. A portion of the second bus bar25that is connected to the source terminals63is formed in a comb-teeth shape. A plurality of the third bus bar supporting parts37are provided so as to be located between the comb teeth. A portion where the plurality of third bus bar supporting parts37and the partition part34that connects the third bus bar supporting parts37are formed also has a comb-teeth shape. The third bus bars28are individually supported by the respective third bus bar supporting parts37.

The connection portion holding part38holds a portion where the first bus bar21and the temperature detection member50are thermally connected to each other. The connection portion holding part38has a support surface38a. The support surface38asupports the detection target portion22bof the first bus bar21. A recess38bis formed in the support surface38a. A nut N is fitted in the recess38b. For example, the recess38bmay be formed to be smaller than the nut N, and the nut N may be press-fitted into the recess38b. The recess38bmay be formed to have the same size as, or to be larger than the nut N, and the nut N may be fitted therein without being press-fitted. The support surface38ais formed at a higher position than the upper surface of the partition part34.

The first frame31is provided with external connection parts39. Here, two stud bolts SB are provided for connection to external conductors. Two stud bolt mounting parts are formed on the first frame31as the external connection parts39. The first frame31is integrally molded in a shape also including the two stud bolts mounting parts. After molding the first frame31, the stud bolts SB are mounted to the respective stud bolt mounting parts. The stud bolts SB can be removed from the respective stud bolt mounting parts. When molding the first frame31, the stud bolts SB may be used as insert components.

The first bus bar21is attached to one of the two stud bolts SB using the outward extending part23. The second bus bar25is attached to the other of the two stud bolts SB using the outward extending part27. The power supply is connected to one of the first bus bar21and the second bus bar25via an external conductive wire. The first load is connected to the other of the first bus bar21and the second bus bar25via an external conductive wire. For example, a terminal is provided at an end portion of each of the external conductive wires. A stud bolt insertion part is formed in the terminal through which the stud bolt SB is passed. As a result of a nut N being fastened to the stud bolt SB in a state in which the stud bolt SB has been passed through the first bus bar21or the second bus bar25and the terminal, the first bus bar21or the second bus bar25and the terminal are kept in contact with each other, and the first bus bar21or the second bus bar25and the external conductive wire are connected to each other.

The second frame40presses the first bus bar21and the second bus bar25toward the first frame31. The second frame40supports the circuit board70. The second frame40includes a frame part41and a proximal end portion holding part45. The second frame40is an integrally molded article that has been integrally molded in a shape including the frame part41and the proximal end portion holding part45.

The frame part41is formed in a tubular shape that is open at the top and the bottom. The frame part41surrounds the periphery of the in-frame accommodating parts22and26. Also, the frame part41surrounds the circuit board70. A circuit board supporting part42and a rib44are provided inward of the frame part41.

Here, four circuit board supporting parts42are provided. A positioning projection43is provided on a bearing surface of one of the four circuit board supporting parts42. The positioning projection43fits into a positioning hole71formed in the circuit board70. Accordingly, the circuit board70is positioned relative to the second frame40. A screw hole42his formed in a bearing surface of each of the remaining three of the four circuit board supporting parts42. The circuit board70is fixed to the second frame40by fastening screws to the screw holes42hand screw insertion holes72of the circuit board70in a state in which the circuit board70is supported by the bearing surfaces of the four circuit board supporting parts42while being positioned by the positioning projection43.

Here, five ribs44are provided. The ribs44are formed at a lower position than the circuit board supporting parts42are. Ribs44A and44B connect inner surfaces of the frame parts41to each other. The ribs44A and44B intersect each other (here, are orthogonal to each other). The rib44A traverses between the detection target portion22band a part of the placement portion22aon which the main bodies61are placed. The rib44B connects two circuit board supporting parts42to each other. The two circuit board supporting parts42are circuit board supporting parts42each provided with the positioning projection43. A rib44C connects the rib44A and an inner surface of the frame part41to each other. A rib44D connects the rib44A and one circuit board supporting part42to each other. The ribs44C and44D extend parallel to the rib44B. The rib44E connects the rib44B and an inner surface of the frame part41to each other. The rib44E extends parallel to the rib44A. The ribs44press the first bus bar21and the second bus bar25toward the first frame31.

The rib44C is provided with the proximal end portion holding part45. The proximal end portion holding part45holds a proximal end portion of the wiring part54that extends continuously with the detection main body part52. Specifically, a groove45ais formed in an upper surface of the rib44C. The groove45ais open upward. The groove45ais formed so as to traverse the rib44C. The proximal end portion of the wiring part54is fitted in the groove45a. A bottom surface of the groove45aconstitutes a support surface for the proximal end portion of the wiring part54. Opposite side surfaces of the groove45apress the proximal end portion from opposite lateral sides. The width of the groove45amay be set to be larger than the width of the proximal end portion of the wiring part54, and the proximal end portion may be held in the groove45ausing an adhesive, or the width of the groove45amay be set to be the same as, or smaller than the width of the proximal end portion of the wiring part54, and the proximal end portion of the wiring part54may be press-fitted into the groove45a.

Window parts46are formed in the second frame40. The window parts46are formed adjacent to the frame part41. The window parts46expose the outward extending parts23and27and the stud bolts SB. Peripheral edges of the window parts46press outer edge portions of the outward extending parts23and27.

The temperature detection member50detects the temperature of the bus bar20. Here, in order to detect the temperature of the switching elements60, the temperature detection member50detects the temperature of the bus bar20. The temperature detection member50detects the temperature of the first bus bar21. A temperature detection result from the temperature detection member50is supplied to a control element. If the temperature of the switching elements60(i.e., the temperature detected by the temperature detection member50) exceeds a predetermined upper limit temperature, the control element switches off all of the switching elements60. The predetermined upper limit temperature is a temperature that is lower than the temperature of the switching elements60when overheated. That is, the control element protects the switching elements60from overheating. If the switching elements60are switched off based on the temperature of the switching elements60, the control element controls the switching elements60to remain off at least until the temperature of the switching elements60falls below a predetermined safe temperature. The predetermined safe temperature is a temperature sufficiently lower than the predetermined upper limit temperature.

The temperature detection member50includes a detection main body part52, a wiring part54, and a thermal connection member56. The temperature detection member50is held by one or more holding parts38and45.

The detection main body part52is provided so as to be capable of detecting the temperature of a detection target. The detection main body part52includes a temperature sensitive element main body, and a pair of lead wires drawn from the temperature sensitive element main body. For example, the temperature sensitive element main body is a thermistor or the like whose resistance value varies according to temperature.

The wiring part54extends from the detection main body part52. A proximal end portion (one end portion) of the wiring part54is electrically connected to the detection main body part52. A distal end portion (the other end portion) of the wiring part54is electrically connected to the circuit board70. The wiring part54is a pair of insulated wires, for example. The pair of insulated wires and the pair of lead wires are connected to each other. A protective member55is provided at the proximal end portion of the wiring part54. The protective member55is a molded resin part or made of a cured adhesive, for example. The protection member55may be a protective tube or the like. The portion at which the protection member55is provided is held by the proximal end portion holding part45. Note that the proximal end portion of the wiring part54refers to a portion extending from the portion connected to at least the detection main body part52to the portion held by the proximal end portion holding part45. The distal end portion of the wiring part54refers to a portion that is connected to at least the circuit board70.

The thermal connection member56thermally connects the detection main body part52and the bus bar20to each other. The connection portion holding part38holds a portion where the thermal connection member56and the bus bar20are thermally connected to each other. The thermal connection member56includes a fixing part57and a mounting part58. The thermal connection member56is one plate member formed in a bent shape, and has a shape including the fixing part57and the mounting part58. The thermal connection member56is also called a lug terminal or the like. The thermal connection member56is made of a material that has good thermal conductivity. The thermal connection member56is made of a metal such as aluminum or a copper. The thermal connection member56need only be a member that has thermal conductivity, and may be a terminal other than a lug terminal.

The fixing part57is formed in a plate shape that is elongated in one direction. A through hole57his formed in the fixing part57. The fixing part57is supported by the first bus bar21. A bolt B is passed through the through hole57h. The bolt B passed through the through holes22hand57his fixed to a nut N. The thermal connection member56and the bus bar20are fixed by the bolt B and the nut N using the through holes22hand57h. The mounting part58extends from the fixing part57.

The mounting part58includes an extending piece58aand fixing pieces58band58c. The extending piece58aextends from the fixing part57. The detection main body part52is placed on the extending piece58a. The extending piece58ais supported by a support surface45bof the proximal end portion holding part45. The fixing pieces58band58care provided at an interval therebetween along the longitudinal direction of the extending piece58a. The fixing piece58bis provided at a position closer to the fixing part57than the fixing piece58cis. A pair of the fixing pieces58bare provided so as to rise from side edges of the extending piece58a. The fixing pieces58bsurround the detection main body part52. The fixing pieces58bare crimped around the detection main body part52. The fixing piece58cis provided at a distal end portion of the extending piece58a. A pair of the fixing pieces58care provided so as to rise from opposite side edges of the extending piece58a. The fixing pieces58csurround the wiring part54. The fixing pieces58care crimped around the wiring part54. Here, the fixing pieces58care crimped around the protection member55. The portion where the fixing pieces58care provided is held by the proximal end portion holding part45. Note that the fixing pieces58chave been omitted fromFIGS.1and2.

The thermal connection member56is supported by an upper surface of the first bus bar21at the connection portion holding part38. Here, the fixing part57is supported by an upper surface of the detection target portion22b. The thermal connection member56is supported by the support surface45bof the proximal end portion holding part45at the proximal end portion holding part45. The support surface45bis a bottom portion of the groove45a. Here, the extending piece58ais supported by the support surface45b. As shown inFIG.4, the height of the support surface45bof the proximal end portion holding part45is smaller than the height of the upper surface of the first bus bar21at the connection portion holding part38. This allows the thermal connection member56to easily come into surface contact with the first bus bar21so that favorable thermal conductivity can be easily achieved.

FIG.4shows a state in which the thermal connection member56is elevated from the support surface45b. For example, the elevated portion is provided with an adhesive that also fixes the thermal connection member56. Accordingly, the thermal connection member56is supported by the support surface45bvia the adhesive. The thermal connection member56may be directly in contact with and supported by the support surface45bby being bent at an intermediate portion of the extending piece58a. The thermal connection member56may also remain elevated from the support surface45b.

The temperature detection member50is held at the connection portion holding part38by the bolt B and the nut N. The temperature detection member50is held at the proximal end portion holding part45using an adhesive or through press-fitting. As such an adhesive, an adhesive having a holding force weaker than the holding force provided by the bolt and the nut is used. For such press-fitting, the width of the proximal end portion holding part45is set such that the holding force obtained through press-fitting is weaker than the holding force provided by the bolt and the nut. Accordingly, the holding force of the connection portion holding part38is greater than the holding force of the proximal end portion holding part45. Here, the holding force refers to a force required to move the temperature detection member50held by the holding parts38and45in the front-rear direction, the left-right direction, the up-down direction, or the like.

The switching elements60switch the first bus bar21and the second bus bar25on or off. That is, the first bus bar21and the second bus bar25are connected to each other when the switching elements60are on. Accordingly, a current flows from the power supply to the first load through the switching elements60. The connection between the first bus bar21and the second bus bar25is disconnected when the switching elements60are off. At this time, the connection between the power supply and the first load is disconnected. When the connection between the power supply and the first load is disconnected, power is supplied to the first load from an auxiliary power supply (e.g., a sub-battery) directly connected to the first load. Note that the switching elements60are not limited to the field-effect transistors60. The number of switching elements60need not be five, and at least one switching element60may be provided.

The circuit board70is a control board that controls the switching elements60. The control element (not shown) is mounted to the circuit board70. For example, the control element is electrically connected to the gate terminals64via a circuit on the circuit board70and the third bus bars28. The control element is a microprocessor (MPU: Micro Processing Unit), for example. For example, a connector is connected to the control element. The connector is provided at a peripheral edge portion of the circuit board70. A control signal is input to the control element from outside the electrical junction box10via a signal line connected to the connector. The control element switches each of the switching elements60on or off in accordance with the input control signal. For example, if a control signal indicating that the starter is to start operating is input, the control element switches off all of the switching elements60. After the engine has been started by the starter, the control element switches on all of the switching elements60.

The positioning hole71for passing the positioning projection43therethrough is formed in the circuit board70. The positioning hole71may be formed to have the same size as, or to be larger than the positioning projection43. Screw insertion holes72are formed in the circuit board70at positions corresponding to the screw holes42h. The screw insertion holes72may have the same size as, or a size different from the size of the positioning hole71. When the size of the positioning hole71and the size of the screw insertion holes72are different from each other, the positioning hole71and the screw insertion holes72can be easily distinguished from each other. Here, the screw insertion holes72is formed to be larger than the positioning hole71. Through holes73and74are formed in the circuit board70. The other end portion of the wiring part54is connected to the through hole73. The other end portion of each gate terminal64is connected to the corresponding through hole74. For example, the other end portion of the wiring part54and the other end portion of the gate terminals64are passed through the through holes73and74, and electrically connected and fixed thereto using solder.

The cover80closes the upper opening of the frame30. The cover80closes the upper opening of the frame part41. The cover80is made of an insulating material such as a resin, or a metal material, for example. For example, the cover80is locked and externally fitted to the frame part41by an engagement structure using a locking projection. The fixing may also be achieved through screwing.

The heat dissipation member82releases heat from the first bus bar21and the second bus bar25. The heat dissipation member82is a heat sink, for example. The heat dissipation member82is made of a material having high thermal conductivity, for example. The heat dissipation member82is made of a metal such as aluminum, for example. The heat dissipation member82is provided below the frame30. The heat dissipation member82is formed to have a size corresponding to the size of the frame30. The heat dissipation member82closes the lower opening of the frame30. The frame30and the heat dissipation member82form a box member including the frame30serving as a peripheral wall, and the heat dissipation member82serving as a bottom wall. Note that a heat dissipation fin may be provided on a lower surface of the heat dissipation member82. For example, the heat dissipation member82and the second frame40are screwed to each other. Also, the first bus bar21, the second bus bar25, the first frame31, and the interposed member84that are disposed between the heat dissipation member82and the second frame40are sandwiched between the heat dissipation member82and the second frame40.

The interposed member84is interposed between the heat dissipation member82and the first and second bus bars21and25. The interposed member84includes an insulating member made of a material having insulating properties. The insulating member insulates the first and second bus bars21and25from the heat dissipation member82. For example, the interposed member84includes an insulating sheet and a grease member. The insulating sheet is formed to have a size corresponding to the size of the heat dissipation member82. The insulating sheet is disposed between the bus bar20and the heat dissipation member82. The grease member is provided at least either between the insulating sheet and the bus bars21and25, or between the insulating sheet and the heat dissipation member82. The grease member increases thermal conductivity by filling the gap between the insulating sheet and the bus bars21and25, and the gap between the insulating sheet and the heat dissipation member82. The grease member is a semisolid member, and can enter gaps. Alternatively, the grease member may be a member, such as an adhesive, that is cured after being in a semisolid state.

With the electrical junction box10configured in the above-described manner, the holding parts38and45that hold the temperature detection member50are integrally molded with the frame30that holds the bus bars21and25. Accordingly, it is possible to hold the temperature detection member50while keeping the number of components as low as possible.

Since the proximal end portion holding part45is provided as the holding part, the detection main body part52that is located close to the proximal end portion holding part45is stabilized.

Since the connection portion holding part38is provided, the thermal connection portion is further held. Here, the connection portion holding part38can hold the nut N.

Since the holding force of the connection portion holding part38is greater than the holding force of the proximal end portion holding part45, the proximal end portion holding part45is more likely to rattle than the connection portion holding part38, and thus stress is less likely to be applied to the connection portion holding part38.

Since the height of the support surface45bof the proximal end portion holding part45is lower than the height of the upper surface of the bus bar21at the connection portion holding part38, the bus bar21and the thermal connection member56can easily come into surface contact with each other at the connection portion.

Embodiment 2

An electrical junction box according to Embodiment 2 will be described.FIG.5is an exploded perspective view showing an electrical junction box110according to Embodiment 2.FIG.6is a plan view showing the electrical junction box110according to Embodiment 2. InFIG.6, the cover80has been omitted.FIG.7is a bottom view showing the electrical junction box110according to Embodiment 2. InFIG.7, the bus bar20and the second frame40have been omitted. Note that the same constituent elements as those described thus far are denoted by the same reference numerals, and the descriptions thereof have been omitted.

The electrical junction box110differs from the electrical junction box10in that intermediate holding parts47,48, and49are provided in addition to the holding parts38and45. The intermediate holding parts47,48, and49are provided on a second frame140. The second frame140is an integrally molded article that has been integrally molded in a shape including the frame part41, the proximal end portion holding part45, and the intermediate holding parts47,48, and49. The components of the electrical junction box110other than the second frame140are the same as those of the electrical junction box10.

The intermediate holding parts47,48, and49are provided in this order from the proximal end portion holding part45along the direction in which the wiring part54extends. The intermediate holding parts47,48, and49hold an intermediate portion of the wiring part54at positions different from each other. Grooves47a,48a, and49aare formed in the intermediate holding parts47,48, and49, respectively. The intermediate portion of the wiring part54is accommodated in the grooves47a,48a, and49a. The intermediate holding parts47and48are provided on the rib44A. The intermediate holding part49is provided on the rib44B. Note that the intermediate portion of the wiring part54is a portion between the proximal end portion and the distal end portion described above.

The intermediate holding part47is provided at a position next to the proximal end portion holding part45in the order from the proximal end portion toward the distal end portion along the direction in which the wiring part54extends. The intermediate holding part47is an example of the proximal end-side intermediate portion holding part. The groove47ais formed so as to traverse the rib44A. The groove47ais formed in the upper surface of the rib44A. The groove47ais open upward. The width of the groove47ais larger than the width of the wiring part54.

At the intermediate holding part48, the groove48ais formed extending parallel to the rib44A. Specifically, a protrusion48bprotruding laterally from the rib44A is provided. The protrusion48bis formed to have an L-shape cross-section. The protrusion48bincludes a protruding piece that protrudes laterally from the rib44A, and a hanging piece that is provided at a distal end of the protruding piece at an interval from the rib44A. A groove47ais formed between the protrusion48band the rib44A. The protruding piece of the protrusion48bconstitutes a bottom portion of the groove47a. The hanging piece of the protrusion48band the rib44A constitute side walls of the groove47a.

The protrusion48bis formed in a region between the groove47aand the rib44B along the longitudinal direction of the rib44A. The protrusion48bis formed on an intermediate portion of the rib44A that is located between the groove47aand the rib44B. The length of the protrusion48bis longer than the length of the groove47a(the width of the rib44A). The length of the protrusion48bis set to be greater than or equal to half the interval between the groove47aof the rib44A and the rib44B, for example. The groove48ais formed in a lower surface of the protrusion48b. The groove48ais open downward. The groove48ais provided over the entire protrusion48balong the direction in which the rib44A extends. The width of the groove48ais larger than the width of the wiring part54.

The intermediate holding part48is provided with retaining pieces48c. The retaining pieces48cprotrude from an edge portion of an opening of the groove48a. The retaining pieces48cclose the opening of the groove48a. Here, the retaining pieces48cprotrude from a distal end of the hanging piece of the protrusion48btoward the rib44A. The width of each retaining piece48cis smaller than the length of the protrusion48b. Slits48S are formed at positions on both sides of a portion of the hanging piece of the protrusion48bthat extends continuously with each retaining piece48c. Accordingly, the portion of the hanging piece that extends continuously with the retaining piece48cconstitutes an elastic piece that can be easily deformed elastically. As a result of the elastic piece being elastically deformed, the wiring part54can easily move from the opening over the retaining pieces48c, and be accommodated in the groove48a.

The intermediate holding part49is provided at a position closest to the connection portion with the circuit board70along the direction in which the wiring part54extends. The groove49ais formed so as to traverse the rib44B. The groove49ais formed in an upper surface of the rib44B. The groove49ais open upward. The width of the groove49ais larger than the width of the wiring part54.

The grooves47aand49aare examples of the first groove. The intermediate holding parts47and49are examples of the first intermediate holding part. The groove48ais an example of the second groove. The intermediate holding part48is an example of the second intermediate holding part. The grooves47aand49aand the groove48aare open in directions opposite to each other.

The wiring part54is fitted to the grooves47a,48a, and49a, but is not press-fitted thereinto. Accordingly, the holding force at the intermediate holding parts47,48, and49is weaker than the holding force of the proximal end portion holding part45and the holding force of the connection portion holding part38. Similarly, the holding force at the intermediate holding parts47,48, and49is weaker than the holding force at the connection portion between the wiring part54and the circuit board70.

With the electrical junction box110configured in the above-described manner, it is also possible to achieve the same effects as those of Embodiment 1. With the electrical junction box110, the holding force at the proximal end-side intermediate portion holding part47is weaker than the holding force of the proximal end portion holding part45and the holding force of the connection portion holding part38. Accordingly, the proximal end-side intermediate portion holding part47is more likely to rattle than the connection portion holding part38and the proximal end portion holding part45, and thus stress is less likely to be applied to the proximal end portion holding part45and the connection portion holding part38.

Since the intermediate holding part48is formed to be longer than the intermediate holding parts47and49, an excess length of the wiring part54is absorbed by the intermediate holding part48. Accordingly, the wiring part54is less likely to dangle.

Since the intermediate holding part48is provided with the retaining pieces48c, the wiring part54is prevented from being dislodged from the longer groove48a.

Since the grooves47aand49aand the groove48aare open in directions opposite to each other, the wiring part54is held at the intermediate holding parts47and49and the intermediate holding part48from sides opposite to each other.

Since the rib44B in which the groove49ais formed extends from the circuit board supporting part42on which the positioning projection43is formed, the intermediate holding part49can hold the wiring part54at a position close to the positioning projection43.

Since the holding force at the intermediate holding parts47,48, and49is weaker than the force holding the wiring part54at the electrical connection portion between the wiring part54and the circuit board70, stress is less likely to be applied to the electrical connection portion.

Modifications

In each of the embodiments, the bus bars21and25are described as constituting the circuit that is to be switched by the switching elements60. However, this is not an essential configuration. The bus bars21and25may be used for a circuit different from the circuit that is to be switched.

In each of the embodiments, some of the holding parts38and45,47,48, and49may be omitted. For example, one of the holding parts38and45may be omitted in Embodiment 1. For example, in Embodiment 2, one or more of the intermediate holding parts47,48, and49of the holding parts38and45,47,48,49may be used, and the rest of the holding parts may be omitted.

The configurations described in the embodiments and the modification may be combined as appropriate as long as there are no mutual inconsistencies.