JP4228955B2 - Electrical junction box - Google Patents

Description

  The present invention relates to an electrical junction box provided in a vehicle such as an automobile.

  Conventionally, as a means of distributing power from a common in-vehicle power supply to each electronic unit, a power distribution circuit is configured by stacking a plurality of bus bar boards, and a circuit structure incorporating a fuse or relay switch is used as a case, etc. An electrical junction box housed in the box is generally known.

For example, Patent Document 1 includes a case that accommodates the circuit structure, which includes a lower cover having a shape that opens upward, and an upper cover that closes an upward opening of the lower cover. The lower cover and the upper cover An electrical junction box is disclosed in which the circuit structure accommodated in the case is waterproofed by being joined in a waterproof state through packing or the like.
Japanese Utility Model Publication No. 6-88133

  In recent years, with the progress of computerization of vehicles, circuit components in which switch means such as relays and semiconductor switching elements are used relatively frequently have been developed. In such a circuit structure, in order to effectively release the heat generated from the switch means to the outside, a heat radiating member made of aluminum or the like is often provided outside. However, if such a whole circuit structure is housed in the case as in Patent Document 1, the heat radiating member is confined in the case and cannot perform its heat radiating function.

  In addition, as an electrical junction box having a circuit structure having such a heat dissipation member, Japanese Patent Laid-Open No. 2003-218562 discloses that the heat dissipation member is provided on a side surface of the circuit structure and accommodates the circuit structure. An electrical junction box is disclosed in which an opening is provided in the side wall of the case and the heat dissipation member protrudes from the opening. In this structure, the gap between the peripheral portion of the opening on the case side and the heat dissipation member of the circuit structure is disclosed. The water intrusion path into the case will occur. Accordingly, in such an electrical junction box, it is desired to provide a waterproof structure for effectively cutting off the intrusion path with a simple structure, but the specific structure is disclosed in Japanese Patent Laid-Open No. 2003-218562. It has not been.

  In view of such circumstances, an object of the present invention is to provide a waterproof structure in an electrical junction box that exposes a heat dissipation member of a circuit structure to the outside of a case.

The invention according to claim 1 includes a circuit structure having a heat dissipation portion and a case for housing the circuit structure, and the circuit is disposed in the case with the heat dissipation portion exposed to the outside of the case. In the electrical junction box in which the structural body is held, an opening for exposing the heat radiating portion is formed on the outer wall of the case, and a sealing material that opens toward the inside of the case over the entire periphery of the peripheral portion of the opening An accommodation groove is formed, and an elastically deformable seal material is provided at the bottom of the seal material accommodation groove, while the circuit component is provided with a seal material presser projecting in a direction opposite to the direction in which the seal material accommodation groove opens. The part is formed in a shape surrounding the heat radiating part of the circuit component and corresponding to the sealing material accommodation groove, and the sealing material pressing part is inserted into the sealing material accommodation groove and contacts the sealing material. That state wherein is configured such that the circuit structure is retained within the casing, the said casing includes a lower cover having a shape opened upward, to the lower cover so as to close the upward opening of the lower cover An upper cover that is joined in a waterproof state, and the opening is formed in the bottom wall of the lower cover, and the bottom of the lower cover is interposed between the seal material accommodation groove in the lower cover and the upper cover joining portion outside thereof. A low floor portion is formed in which a wall sinks to a position lower than the sealing material accommodation groove .

The invention according to claim 2, in which the electrical connection box according to claim 1, ribs protruding upward are formed between the sealing member receiving groove and the lower floor portion.

According to a third aspect of the present invention, in the electrical junction box according to the first or second aspect of the present invention, the circuit component is positioned on the inner side of the sealing material pressing portion and at least a seal of the peripheral portion of the opening in the case. The cover part which covers the upper end part of the part which forms a material accommodation groove | channel from an inner side is formed.

  According to the first aspect of the present invention, the seal material accommodation groove that opens toward the inside of the case is formed on the entire periphery of the periphery of the opening formed in the outer wall of the case, and the bottom of the seal material accommodation groove On the other hand, a seal material that can be elastically deformed is provided on the circuit structure body, and a seal material pressing portion that protrudes in a direction opposite to the direction in which the seal material accommodation groove opens surrounds the heat radiation section of the circuit structure body. Formed in a shape corresponding to the sealing material accommodation groove, and the circuit component is held in the case in a state in which the sealing material pressing portion is inserted into the sealing material accommodation groove and is in contact with the sealing material. Therefore, by inserting the sealing material pressing portion of the circuit structure into the sealing material receiving groove, the heat radiating portion of the circuit structure is removed from the opening formed in the outer wall of the case. Exposed so it is possible to maintain the heat radiation of the heat radiating portion. Also, the seal material provided at the bottom of the seal material accommodation groove can be easily and reliably contacted with the seal material press portion of the circuit component simply by inserting the seal material press portion into the seal material accommodation groove. Can be made. By this contact, the water intrusion path into the case at the peripheral edge of the opening can be blocked, and the inside of the case can be waterproofed.

  Here, for example, sealing is possible by arranging a sealing material on a flat plane and pressing the sealing material from above with a sealing material pressing portion. In this case, however, the sealing material pressing portion is used as the sealing material. It is necessary to perform an alignment operation while visually confirming the relative position of the sealing material and the sealing material pressing portion so that the sealing material is securely pressed over the entire circumference. Since a housing groove is formed, a sealing material is provided in the sealing material housing groove, and a structure in which the sealing material pressing portion of the circuit component is inserted into the sealing material housing groove, only the insertion is performed. Thus, the sealing material and the sealing material pressing portion can be reliably brought into contact with each other.

  As a method for waterproofing the peripheral edge of the opening, for example, a sealing material may be sandwiched between the inner peripheral surface of the opening and the outer peripheral surface of the circuit component, but in this case, the inner peripheral surface of the opening Since the gap between the circuit board and the outer peripheral surface of the circuit structure is likely to vary due to manufacturing errors or the like, the contact pressure applied to the sealing material sandwiched between them tends to be uneven, and it is difficult to ensure waterproofing. On the other hand, in the present invention, the sealing material accommodation groove is opened toward the inside of the case, and the seal material and the sealing material pressing portion are brought into contact with each other in this direction, whereby the outer peripheral surface of the sealing material pressing portion is formed. Even if a manufacturing error occurs, a substantially uniform contact pressure can be applied to the sealing material over the entire circumference, and waterproofing can be ensured.

In addition, the case includes a lower cover having a shape that opens upward, and an upper cover that is joined to the lower cover in a waterproof state so as to close the upward opening of the lower cover, and the opening is formed in a bottom wall of the lower cover. Therefore, in a state where the upper cover is not joined to the lower cover, the sealing member pressing portion of the circuit component is easily inserted from above into the sealing member receiving groove formed in the bottom wall of the lower cover. be able to.

In addition , a low floor portion in which the bottom wall of the lower cover sinks to a position lower than the seal material accommodation groove is formed between the seal material accommodation groove in the lower cover and the upper cover joint portion on the outside thereof. Even if water enters the case from the joint portion between the lower cover and the upper cover, water accumulates on the low floor portion, so that this water can be prevented from being transmitted to the circuit structure as it is.

According to the second aspect of the present invention, since the rib protruding upward is formed between the seal material accommodation groove and the low floor portion, the rib allows the lower cover and the upper cover to be separated from each other. It is possible to more effectively prevent water that has entered the case from being transmitted to the circuit structure as it is.

According to the invention of claim 3 , the upper end portion of the peripheral portion of the opening in the case that forms at least the sealing material accommodation groove located on the inner side of the sealing material pressing portion is provided on the circuit structure. Since the cover part which covers from the inside is formed, even if water comes toward the opening peripheral edge part of the lower cover, it is possible to prevent the water from directly entering the sealing material accommodation groove by the cover part. it can. Therefore, the water intrusion path into the case can be closed in steps by the sealing material and the covering portion, and the waterproofness at the peripheral edge of the opening can be further improved.

  The best mode for carrying out the present invention will be described with reference to the drawings.

  The electrical junction box of the present invention is shown in FIG. The electrical junction box includes a circuit structure 10 and a case for housing the circuit structure 10. In this specification, for convenience of explanation, the lower right front side in FIG. 1 is referred to as the front side, and the height direction is referred to as the up and down direction.

  The circuit structure 10 is configured by laminating a plurality of bus bar substrates to form a power distribution circuit, which is covered with a housing 12, and the housing 12 is provided in the power distribution circuit. Switching means such as a relay and a semiconductor switching element are provided.

  The lower surface of the housing 12 is configured as a heat radiating portion 12a for releasing heat generated from the switching means to the outside, and an electrical component for mounting an electrical component such as a fuse on the upper surface of the housing 12 The mounting portion 12b is formed at a plurality of locations. The casing 12 is made of an insulating material such as a synthetic resin, and the heat radiating portion 12a is made of a material having high thermal conductivity, such as an aluminum alloy or a copper alloy, incorporated in the lower surface of the casing 12. It is configured.

  The case includes a lower cover 20 having a shape that opens upward, and an upper cover 30 that closes an upward opening of the lower cover 20. The lower cover 20 and the upper cover 30 are made of an insulating material such as synthetic resin.

  As shown in FIG. 2, the lower cover 20 has a substantially rectangular shape in plan view extending in the front-rear direction and has a bottomed container shape, and its bottom surface gradually increases in depth from the rear side toward the front side. It is inclined to become deep. In addition, a partition wall 28 is provided in the lower cover 20 at about ¼ from the left side in the left-right width direction. The circuit component 10 is accommodated on the right side of the partition wall 28, and another control unit is provided on the left side. 50 is accommodated.

  The front side wall and the rear side wall of the lower cover 20 are formed with cut portions 29a and 29b cut from the upper end portions thereof, and external wiring is connected to the inside of the case through the cut portions 29a and 29b. It enters and is connected to the circuit structure 10 and the control unit 50. The notches 29a and 29b and the wiring are waterproofed by grommets (not shown) formed in a shape corresponding to the shapes of the notches 29a and 29b.

  The upper cover 30 has a bottomed container shape that opens downward, and the side wall of the upper cover 30 and the side wall of the lower cover 20 are joined in a waterproof state. The joining structure between the upper cover 30 and the lower cover 20 will be described in detail later.

  An opening 20 a for exposing the heat dissipating part 12 a of the circuit component 10 to the outside of the lower cover 20 is formed in a substantially right half surface portion of the bottom wall of the lower cover 20. Here, in order to specifically explain the structure in the vicinity of the opening 20a and the joining structure between the lower cover 20 and the upper cover 30, a front sectional view of the electrical junction box in the II section of FIG. 2 is shown in FIG. .

  On the peripheral edge of the opening 20a of the lower cover 20, a sealing material accommodation groove 22 is formed that opens upward over the entire circumference. A sealing material 40 that is elastically deformable is provided at the bottom of the sealing material accommodation groove 22. The sealing material 40 is, for example, rubber packing or the like, and is accommodated in the sealing material accommodation groove 20 without a gap in the width direction.

  The sealing material accommodation groove 22 is composed of an outer peripheral wall and an inner peripheral wall protruding upward, and the outer peripheral wall protrudes to a high position as it is to become a rib 26.

  A low floor portion 24 in which the bottom wall of the lower cover 20 sinks to a position lower than the sealing material accommodation groove 22 is formed between the sealing material accommodation groove 22 and the side wall of the lower cover 20. .

  The upper end of the side wall of the lower cover 20 is an upper cover joint 23 that is joined to the upper cover 30.

  On the other hand, in the vicinity of the center of the side surface of the housing 12 in the circuit structure 10, an arm portion 14 projecting outward from the side surface is formed over the entire circumference of the housing 12, and further, a seal projecting downward is formed at the tip portion thereof. A material pressing portion 14a is formed. The sealing material pressing portion 14 a has a shape that surrounds the heat radiating portion 12 a of the circuit component and corresponds to the sealing material accommodation groove 22 in the lower cover 20. Further, the seal material pressing portion 14 a has a width to be inserted in a state of loosely fitting in the seal material accommodation groove 22. The circuit component 10 is held in the case in a state where the seal material pressing portion 14a is inserted into the seal material accommodation groove 22 and is in contact with the seal material 40.

  Further, the arm portion 14 is formed with a cover portion 14b that protrudes downward at a position inside the seal material pressing portion 14a, and the upper end of the inner peripheral wall constituting the seal material accommodation groove 22 by the cover portion 14b. The portion 22a is covered from the inside.

  On the other hand, a sealing material receiving groove 32 that opens downward is formed on the side wall of the upper cover 30, and a sealing material 42 such as rubber packing that can be elastically deformed is provided at the bottom of the sealing material receiving groove 32. ing. The upper cover joint portion 23 of the lower cover 20 is inserted into the seal material accommodation groove 32 of the upper cover 30, and the upper cover joint portion 32 comes into contact with the seal material 42, whereby the lower cover 20 and the upper cover 30. And are joined in a waterproof state.

  Since the electrical junction box of the present invention is configured as described above, by inserting the sealing material pressing portion 14a of the circuit component 10 into the sealing material accommodation groove 22 of the lower cover 20, the circuit component 10 The heat radiation part 12a can be exposed to the outside of the lower cover 20 through the opening 20a formed in the bottom wall of the lower cover 20, and the heat radiation property of the heat radiation part 12a can be maintained. Further, the sealing material 40 provided at the bottom of the sealing material accommodation groove 22 and the sealing material of the circuit component 10 can be obtained by simply inserting the sealing material pressing portion 14 a into the sealing material accommodation groove 22. The presser portion 14a can be reliably brought into contact. By this contact, the water intrusion path into the case at the periphery of the opening 20a can be blocked, and the periphery of the opening 20a can be waterproofed.

  In addition to this, the lower cover 20 and the upper cover 30 are joined in a waterproof state via a sealing material 42, and the notches 29a and 29b of the lower cover 20 are also waterproofed by grommets or the like, so that the inside of the case is waterproofed. Can do.

  Here, for example, the sealing material 40 may be disposed on a flat plane and the sealing material 40 may be pressed by the sealing material pressing portion 14a from above, but in this case, the sealing material pressing portion Although it is necessary to perform an alignment operation while visually confirming the relative positions of the sealing material 40 and the sealing material pressing portion 14a so that the sealing material 40 is securely pressed over the entire circumference, the electrical junction box of the present invention Then, the sealing material accommodation groove 22 is formed in the peripheral edge portion of the opening 20 a in the lower cover 20, the sealing material 40 is provided in the sealing material accommodation groove 20 a, and the sealing material of the circuit component 10 is provided in the sealing material accommodation groove 22. Since the structure for inserting the presser portion 14a is adopted, the seal material 40 and the seal material presser portion 14a can be reliably brought into contact with each other only by performing the insertion. .

  As a method of waterproofing the peripheral edge of the opening 20a, for example, a sealing material may be sandwiched between the inner peripheral surface of the opening 20a and the outer peripheral surface of the circuit component 10, but in this case, the opening 20a Since the gap between the inner peripheral surface of the circuit member 10 and the outer peripheral surface of the circuit component 10 is likely to vary due to manufacturing errors or the like, the contact pressure applied to the sealing material sandwiched therebetween is likely to be uneven, and it is difficult to ensure waterproofing. On the other hand, in the electrical junction box of the present invention, the sealing material accommodation groove 22 opens upward, and the sealing material pressing portion 14a is brought into contact with the sealing material 40 and the sealing material pressing portion 14a in this direction. Even if a manufacturing error of the outer peripheral surface occurs, a substantially uniform contact pressure can be applied to the sealing material 40 over the entire periphery, and waterproofing can be ensured.

  On the other hand, in the electrical junction box of the present invention, the case that houses the circuit structure 10 is waterproofed to the lower cover 20 having a shape that opens upward, and the lower cover 20 so as to close the upward opening of the lower cover 20. Since the opening 20a is formed in the bottom wall of the lower cover 20, the upper cover 30 is formed on the bottom wall of the lower cover 20 in a state where the upper cover 30 is not bonded to the lower cover 20. The sealing material pressing portion 14a of the circuit component 10 can be easily inserted into the sealing material accommodation groove 22 formed from above.

  Further, the lower floor portion 24 in which the bottom wall of the lower cover 20 sinks to a position lower than the sealing material accommodation groove 22 between the sealing material accommodation groove 22 in the lower cover 20 and the upper cover joint portion 23 on the outer side. Therefore, even if water enters the case from the joint portion between the lower cover 20 and the upper cover 30, water accumulates on the low floor portion 24. Can be prevented from being transmitted to. Therefore, it is possible to improve the reliability of waterproofing to the circuit structure 10 accommodated in the case.

  Further, since a rib 26 protruding upward is formed between the seal material accommodation groove 22 and the low floor portion 24, the rib 26 allows the case from the joint portion between the lower cover 20 and the upper cover 30. It is possible to more effectively prevent the water that has entered inside from being transmitted to the circuit structure 10 as it is.

  On the other hand, the circuit component 10 is formed with a cover portion 14b that covers the upper end portion 22a of the inner peripheral wall constituting the sealing material accommodation groove 22 in the lower cover 20 from the inside, so that the peripheral portion of the opening 20a of the lower cover 20 is formed. Even if the water comes toward the vicinity, it is possible to prevent the water from directly entering the sealing material accommodation groove 22 by the cover portion 14b. Therefore, the water intrusion path into the case can be closed in steps by the sealing material 40 and the covering portion 14b, and the waterproofness at the peripheral edge of the opening 20a can be further improved.

  The electrical junction box of the present invention is not limited to the form shown in the above embodiment, and various modifications can be made without departing from the spirit of the electrical junction box.

  For example, in the above embodiment, the lower surface of the housing 12 in the circuit structure 10 is configured as the heat radiating portion 12a. However, the heat radiating portion 12a may be formed on a part of the lower surface of the housing 12. Absent. In this case, as shown in the embodiment, it is not necessary to provide the arm portion 14 on the side surface of the housing 12, and the sealing material pressing portion 14a and the sealing material pressing portion 14a are directly provided on the lower surface of the housing 12 so as to surround the heat radiating portion 12a. The cover portion 14b may be formed.

  In the above embodiment, the sealing material accommodation groove 22 in the lower cover 20 is configured by the inner peripheral wall and the outer peripheral wall. However, the bottom wall of the lower cover 20 at the peripheral edge of the opening 20a is shaved downward from the inner side. It is also possible to form the sealing material accommodation groove 22. In this case, the ribs 26 protruding upward can be formed slightly outside the sealing material accommodation groove 22 and between the sealing material accommodation groove 22 and the low floor portion 24. As described above, the rib 26 only needs to be formed between the seal material accommodation groove 22 and the low floor portion 24, and the portion constituting the seal material accommodation groove 22 is directed upward as shown in the embodiment. It does not have to be formed in a protruding form.

  In addition, since the electrical junction box of the present invention can be attached to the attachment location in an inclined posture, the opening direction of the sealing material accommodation groove 22 and the protruding direction of the rib 26 need to be accurately vertically upward. It may be inclined according to the posture of the electrical junction box.

  Furthermore, the opening 20a that exposes the circuit component 10 need not be formed in the bottom wall of the lower cover 20, and may be formed in the side wall. In this case, the low floor portion 24 and the rib 24 may not be formed. Further, the case can be constituted by a cover divided into left and right.

It is a disassembled perspective view of the electrical junction box of this invention. It is a top view of the lower cover which concerns on this invention. It is front sectional drawing of the said electrical-connection box in the II cross section of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Circuit structure 12a Heat radiation part 14a Sealing material pressing part 14b Cover part 20 Lower cover 20a Opening 22 Sealing material accommodation groove 22a Upper end part 23 Upper cover junction part 24 Low floor part 26 Rib 30 Upper cover 40, 42 Sealing material

Claims (3)

An electrical connection comprising a circuit structure having a heat radiating portion and a case for housing the circuit structure, wherein the circuit structure is held in the case with the heat radiating portion exposed to the outside of the case In the box, an opening for exposing the heat dissipating part is formed in the outer wall of the case, and a sealing material accommodation groove that opens toward the inner side of the case is formed in the peripheral part of the opening. A sealing material that can be elastically deformed is provided at the bottom of the material accommodation groove, and a sealing material pressing portion that projects in a direction opposite to the direction in which the sealing material accommodation groove opens is provided on the circuit configuration body. Formed in a shape corresponding to the sealing material accommodation groove, and the sealing material pressing portion is inserted into the sealing material accommodation groove and is in contact with the sealing material. Wherein is configured such that the circuit structure is maintained,
The case includes a lower cover having a shape that opens upward, and an upper cover that is joined to the lower cover in a waterproof state so as to block the upward opening of the lower cover, and the opening is formed in a bottom wall of the lower cover Has been
A low floor portion in which the bottom wall of the lower cover sinks to a position lower than the seal material accommodation groove is formed between the seal material accommodation groove and the outer cover joint portion outside the lower cover. And electrical junction box. The electrical junction box according to claim 1,
An electrical junction box , wherein a rib protruding upward is formed between the sealing material accommodation groove and the low floor portion . In the electrical junction box according to claim 1 or 2,
The circuit structure is formed with a cover portion that is located on the inner side of the seal material pressing portion and covers at least the upper end portion of the peripheral portion of the opening in the case from which the seal material accommodation groove is formed . An electrical junction box characterized by that.

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