Member junction structure and electric junction box

A member junction structure includes a first member provided with a first press-fitting portion and a second press-fitting portion, and a second member provided with a first press-fitted portion and a second press-fitted portion and configured to be installed on the first member by moving in a first direction which is a predetermined one direction with respect to the first member. In a state where the second member is halfway to be installed on the first member, the first press-fitting portion is inserted into the second press-fitted portion, thereby providing a guide for installing the second member on the first member. In a state where the second member is completely installed on the first member, the first press-fitting portion is press-fitted into the first press-fitted portion, and the second press-fitting portion is press-fitted into the second press-fitted portion.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is based on, and claims priority from Japanese Patent Application No. 2020-060124, filed on Mar. 30, 2020, the entire contents of which are incorporated protein by reference.

TECHNICAL FIELD

The disclosure relates to a member junction structure and a electric junction box.

BACKGROUND

Conventionally, when the two resin brackets are joined to each other, an engaging portion of a first resin bracket is engaged with an engaged portion of a second resin bracket. In this engagement, the engagement portion of the first resin bracket and the engaged portion of the second resin bracket are engaged by zero-touch or press-fitting. That is, the two resin brackets are joined to each other by a transition fitting or an interference fitting.

This structure prevents looseness between the two resin brackets caused by vibration or the like of the vehicle. Patent Document 1 (JP 2010-112509 A) is described as a conventional technical document.

SUMMARY

Incidentally, in the conventional junction structure, in order to increase a joining strength of the two resin brackets (first and second members), if the two resin brackets are joined by press-fitting, the following problems may occur.

In order to press-fitting the two resin brackets, a large force is required, and it is difficult to press-fit them by bare hands without using a dedicated press machine or the like. Therefore, in some cases, the two resin brackets are temporarily press-fitted with bare hands, and then a main press-fitting is performed by using a dedicated press machine or the like to end the press-fitting.

However, if the press-fitting amount in the temporary press-fitting between the two resin brackets is insufficient, there is a possibility that the second resin bracket is inclined obliquely with respect to the first resin bracket when the main press-fitting is performed by using a dedicated press machine or the like. If the main press-fitting is attempted while the resin bracket is inclined obliquely, the press-fitting portion and the press-fitted portion of the resin bracket may be damaged.

Therefore, by forming an oblique deep guide surface (long slope in an insertion direction) at at least one of the end of the press-fitting portion of the first resin bracket and the end of the press-fitting portion of the second resin bracket, it is possible to secure a sufficient press-fitting amount in the temporary press-fitting between the two resin brackets.

However, if the deep guide surface is formed, when the second resin bracket is fully press-fitted into the first resin bracket and the junction is completed, the area of the contact surface between the press-fitting portion of the first resin bracket and the press-fitted portion of the second resin bracket becomes small, and the joining strength between two resin brackets becomes weak, and there is a possibility that looseness occurs between two resin brackets.

It is an object of the present application to provide a member junction structure and a electric junction box which can secure a sufficient amount of a temporary press-fitting, facilitate a main press-fitting, and secure the joining strength between two members after the main press-fitting when the first member and the second member are joined to each other by press-fitting.

A member junction structure according an embodiment includes a first member provided with a first press-fitting portion and a second press-fitting portion, and a second member provided with a first press-fitted portion and a second press-fitted portion, and configured to be installed on the first member by moving in a first direction which is a predetermined one direction with respect to the first member. In a state where the second member is halfway to be installed on the first member, the first press-fitting portion is inserted into the second press-fitted portion, thereby providing a guide for installing the second member on the first member. In a state where the second member is completely installed on the first member, the first press-fitting portion is press-fitted into the first press-fitted portion, and the second press-fitting portion is press-fitted into the second press-fitted portion.

The first member and the second member may be fitted in at least one of: a first fitting mode where the second member is completely installed on the first member and when the first press-fitting portion is press-fitted into the first press-fitted portion, the first member and the second member are fitted in an interference-fitting state at a plurality of places in a predetermined direction different from the first direction; and a second fitting mode where the second member is completely installed on the first member and when the second press-fitting portion is press-fitted into the second press-fitted portion, the first member and the second member are fitted in an interference-fitting state at a plurality of places in a predetermined direction different from the first direction.

When a predetermined direction crossing the first direction is defined as a second direction, in the first fitting mode, the first member and the second member may be fitted at the plurality of places in the second direction in an interference-fitting state.

When a predetermined direction crossing the first direction is defined as a second direction, in the second fitting mode, the first member and the second member may be fitted at the plurality of places in the second direction in an interference-fitting state.

The guide in the state where the second member is halfway to be installed on the first member may be a guide for positioning the second member with respect to the first member in a direction orthogonal to the moving direction of the second member.

The first press-fitting portion and the second press-fitting portion of the first member may be separated from each other in the first direction; between the first press-fitting portion and the second press-fitting portion of the first member, a press-fitting portion intermediate portion may be provided; the first press-fitted portion and the second press-fitted portion of the second member may be separated from each other in the first direction; between the first press-fitted portion and the second press-fitted portion of the second member, a press-fitted portion intermediate portion may be provided; and in a state where the second member is completely installed on the first member, the press-fitted portion intermediate portion may be slightly separated from the press-fitted portion intermediate portion.

An electric junction box according to embodiment includes a resin bracket press-fitting structure including a first resin bracket and a second resin bracket. The first resin bracket includes a first resin bracket body portion, a first press-fitting portion projecting from the first resin bracket body portion, a press-fitting portion intermediate portion adjacent to the first press-fitting portion in a first direction, which is a predetermined one direction, and projecting from the first resin bracket body portion, and a second press-fitting portion adjacent to the press-fitting portion intermediate portion in the first direction and projecting from the first resin bracket body portion. The second resin bracket includes a second resin bracket body portion, a first press-fitted portion formed of a recess provided in the second resin bracket body portion, a press-fitted portion intermediate portion adjacent to the first press-fitted portion in the first direction, and formed of a recess provided in the second resin bracket body portion, and a second press-fitted portion adjacent to the of the press-fitted portion intermediate portion in the first direction and formed of a recess provided in the second resin bracket body portion. By moving the second resin bracket relative to the first resin bracket in the first direction, the first press-fitting portion is press-fitted into the first press-fitted portion, and the second press-fitting portion is press-fitted into the second press-fitted portion.

According to the embodiment, it is possible to provide the member junction structure and the electric junction box which can secure a sufficient amount of the temporary press-fitting, facilitate the main press-fitting, and secure joining strength between two members after the main press-fitting.

DETAILED DESCRIPTION

As illustrated inFIGS.1to7, a member junction structure1according to an embodiment is used when a first member3and a second member5are joined to each other. The first member3may be, for example, a first resin bracket, and the second member5may be, for example, a second resin bracket. Also, the “member junction structure” may be called as a “member press-fitting structure” or a “resin bracket press-fitting structure” or a “resin bracket junction structure”.

Here, for convenience of explanation, a predetermined direction is defined as a length direction, another predetermined direction orthogonal to the length direction is defined as a width direction, and a direction orthogonal to the length direction and the width direction is defined as a height direction. Note that the height direction is not necessarily in a vertical direction.

The first member3is provided with a first press-fitting portion7and a second press-fitting portion9. The second member5is provided with a first press-fitted portion11and a second press-fitted portion13.

In the member junction structure1, the second member5is moved in a first direction (height direction) which is a predetermined one direction with respect to the first member3(see an arrow A8inFIG.8B). By this movement, the first press-fitted portion11is press-fitted with the first press-fitting portion7, and the second press-fitted portion13is press-fitted with the second press-fitting portion9. Thus the second member5is installed integrally with the first member3.

In an installation halfway state where the second member5is in the middle of being installed on the first member3(seeFIG.8B), the first press-fitting portion7is inserted into the second press-fitted portion13to provide a guide for installing the second member5on the first member3. With this guide, the second member5can move only in the height direction while maintaining a fixed attitude with respect to the first member3.

In an installation end state (seeFIGS.1to7and8A) where the second member5has been installed on the first member3, the first press-fitted portion11is press-fitted with the first press-fitting portion7, and the second press-fitted portion13is press-fitted with the second press-fitting portion9.

The second member5is installed on the first member3by linearly moving the second member5from an upper side to a lower side in the height direction with respect to the first member3while maintaining the positions of the first member3and the second member5from an installation preparation state. In the installation preparation state, the first member3in a predetermined posture and the second member5in a predetermined posture are separated by a predetermined distance in a predetermined positional relationship.

More specifically, in the installation preparation state, the first press-fitted portion11and the second press-fitted portion13of the second member5are arranged in this order from the upper side to the lower side in the height direction. The first press-fitting portion7and the second press-fitting portion9of the first member3are arranged in this order from the upper side to the lower side in the height direction.

In the installation preparation state, the second member5is positioned on the upper side of the first member3away from the first member3in the height direction. In the installation preparation state, the positions of the first press-fitting portion7of the first member3and the second press-fitting portion9of the first member3, and the positions of the first press-fitted portion11of the second member5and the second press-fitted portion13of the second member5substantially coincide with each other in the length and width directions.

When the second member5is moved downward by a predetermined distance with respect to the first member3in the installation preparation state, the installation halfway state is established.

In the installation halfway state, the second press-fitted portion13of the second member5is fitted with the first press-fitting portion7of the first member3, and the first press-fitting portion7is engaged with the second press-fitted portion13. However, in the installation halfway state, the first press-fitted portion11of the second member5is not engaged with the first press-fitting portion7of the first member3. More specifically, in the installation halfway state, the first press-fitting portion7of the first member3is not fitted to the second press-fitted portion13of the second member5in an interference-fitting state, but the first press-fitting portion7of the first member3is fitted to the second press-fitted portion13of the second member5in a clearance-fitting state.

In the installation halfway state, the second member5is engaged with the first member3with a slight looseness. Therefore, the second member5can be moved almost linearly only downwardly with respect to the first member3in the installation halfway state.

When the second member5is further moved downward by a predetermined distance with respect to the first member3from the installation halfway state, the installation end state is completed.

In the installation end state, the first press-fitted portion11of the second member5is press-fitted with the first press-fitting portion7of the first member3. That is, in the installation end state, the first press-fitted portion11is fitted with the first press-fitting portion7in an interference-fitting state.

In the installation end state, the second press-fitted portion13of the second member5is press-fitted with the second press-fitting portion9of the first member3. That is, in the installation end state, the second press-fitting portion9is fitted to the second press-fitted portion13in an interference-fitting state.

In the member junction structure1, the first member3and the second member5are fitted to each other in at least one of the following first fitting mode and second fitting mode.

In the first fitting mode, when the second member5is completely installed on the first member3and the first press-fitted portion11is press-fitted into the first press-fitting portion7, the first member3and the second member5are fitted in an interference-fitting state at a plurality of places (e. g., two places) in a predetermined direction. The predetermined direction in the first fitting mode is a predetermined direction different from the first direction (height direction).

In the second fitting mode, when the second member5is completely installed on the first member3and the second press-fitting portion9is press-fitted into the second press-fitted portion13, the first member3and the second member5are fitted in an interference-fitting state at a plurality of places (e. g., two places) in a predetermined direction. The predetermined direction in the second fitting mode is a predetermined direction different from the first direction (height direction), and is, for example, the same direction as the predetermined direction in the first fitting mode.

Here, a predetermined direction crossing (e.g., orthogonal) to the first direction (height direction) is defined as a second direction (the length direction), and a direction crossing (e.g., orthogonal) to the first direction and the second direction is defined as a third direction (the width direction).

In the first fitting mode, the first member3and the second member5are fitted at a plurality of places (e. g., two places) in the length direction in an interference-fitting state. More specifically, in the installation end state, the second member5pinches the first member3in the length direction, but there are two places where the first member3is pinched. The two pinched places are separated from each other in the width direction.

In the first fitting mode, the first member3and the second member5are fitted to each other at a plurality of places (e. g., two places) in the width direction. More specifically, in the installation end state, the second member5pinches the first member3in the width direction, but there are two places where the first member3is pinched. The two pinched places are separated from each other in the length direction.

In the second fitting mode, similarly to the first fitting mode, the first member3and the second member5are fitted at a plurality of places (e. g., two places) in the length direction in an interference-fitting state. More specifically, in the installation end state, the second member5pinches the first member3in the length direction, but there are two places where the first member3is pinched. The two pinched places are separated from each other in the width direction.

In the second fitting mode, similarly to the first fitting mode, the first member3and the second member5are fitted at a plurality of places (e. g., two places) in the width direction in an interference-fitting state. More specifically, in the installation end state, the second member5pinches the first member3in the width direction, but there are two places where the first member3is pinched. The two pinched places are separated from each other in the width direction.

With the guide of the second member5in the installation halfway state, the second member5is positioned with respect to the first member3in a direction orthogonal to the moving direction of the second member5. That is, with the guide of the second member5in the installation halfway state, the second member5is positioned with respect to the first member3in both the length and width directions.

Further, with the guide of the second member5in the installation halfway state, the posture of the second member5with respect to the first member3around the axis extending in the height direction (turning angle) can be maintained substantially constant. Further, with the guide of the second member5in the installation halfway state, the posture of the second member5with respect to the first member3around the axis extending in the length direction (turning angle) can be maintained substantially constant. Further, with the guide of the second member5in the installation halfway state, the posture of the second member5with respect to the first member3around the axis extending in the width direction (turning angle) can be maintained substantially constant.

The first member3is provided with a press-fitting portion intermediate portion15, in addition to the first press-fitting portion7and the second press-fitting portion9. The first press-fitting portion7and the second press-fitting portion9are separated from each other in the height direction. The press-fitting portion intermediate portion15is provided between the first press-fitting portion7and the second press-fitting portion9. The press-fitting portion intermediate portion15is connected to both the first press-fitting portion7and the second press-fitting portion9.

The second member5is provided with a press-fitted portion intermediate portion17, in addition to the first press-fitted portion11and the second press-fitted portion13. The first press-fitted portion11and the second press-fitted portion13are separated from each other in the height direction. The press-fitted portion intermediate portion17is provided between the first press-fitted portion11and the second press-fitted portion13. The press-fitted portion intermediate portion17is connected to both the first press-fitted portion11and the second press-fitted portion13.

In the installation end state where the second member5is completely installed in the first member3, the press-fitted portion intermediate portion17is slightly separated from the press-fitting portion intermediate portion15in the length and width directions.

Here, the first member3is assumed to the first resin bracket and the second member5is assumed to the second resin bracket as an example, and the member junction structure1will be further described.

The first resin bracket3includes a first resin bracket body portion19, the first press-fitting portion7, the press-fitting portion intermediate portion15, and the second press-fitting portion9. The first resin bracket3is integrally molded.

The first press-fitting portion7, the second press-fitting portion9, and the press-fitting portion intermediate portion15protrude from the first resin bracket body portion19from a first end which is one end in the width direction (third direction).

The press-fitting portion intermediate portion15is disposed below the first press-fitting portion7in the height direction, and is adjacent to the first press-fitting portion7. The second press-fitting portion9is disposed below the press-fitting portion intermediate portion15in the height direction, and is adjacent to the press-fitting portion intermediate portion15.

The second resin bracket5includes a second resin bracket body portion21, the first press-fitted portion11, the press-fitted portion intermediate portion17, and the second press-fitted portion13. The second resin bracket5is integrally molded.

The first press-fitted portion11, the press-fitted portion intermediate portion17, and the second press-fitted portion13are formed of recess portions provided in the second resin bracket body portion21. The recess portions are recessed from the second end to the first end side in the width direction.

The press-fitted portion intermediate portion17is disposed below the first press-fitted portion11in the height direction and is adjacent to the first press-fitted portion11. The second press-fitted portion13is disposed below the press-fitted portion intermediate portion17in the height direction, and is adjacent to the press-fitted portion intermediate portion17.

By moving the second resin bracket5with respect to the first resin bracket3in the height direction, the first press-fitting portion7is press-fitted into the first press-fitted portion11, and the second press-fitting portion9is press-fitted into the second press-fitted portion13.

In the installation halfway state where the second resin bracket5is in the middle of being installed on the first resin bracket3, the second press-fitted portion13of the second resin bracket5is fitted with the first press-fitting portion7of the first resin bracket3in a clearance fitting state. Thus, in the installation halfway state, the second resin bracket5can be moved almost linearly only to the lower side with respect to the first resin bracket3.

The engagement between the first press-fitting portion7and the second press-fitted portion13in the installation halfway state may be in a zero-touch state (fitting state of the transition fitting). In the fitting state of the transition fitting, a very small interference (indentation allowance) may be present.

In an installation end state where the second resin bracket5is completely installed on the first resin bracket3, the first press-fitting portion7is press-fitted into the first press-fitted portion11, the second press-fitting portion9is press-fitted into the second press-fitted portion13, and the first resin bracket3and the second resin bracket5are integrated.

In the installation end state, the press-fitted portion intermediate portion17is slightly separated from the press-fitting portion intermediate portion15. In other words, in the installation end state, the surface of the press-fitted portion intermediate portion17and the surface of the press-fitting portion intermediate portion15are not in contact with each other, and a slight gap23(seeFIGS.3,6,7, and the like) is formed between the surface of the press-fitted portion intermediate portion17and the surface of the press-fitting portion intermediate portion15.

The installation of the second resin bracket5on the first resin bracket3will be further described. During a period from the installation preparation state to the installation end state through the installation halfway state, the first press-fitting portion7, the press-fitting portion intermediate portion15, and the second press-fitting portion9of the first resin bracket3are inserted into the second press-fitted portion13of the second resin bracket5in this order.

During the period from the installation preparation state to the installation end state through the installation halfway state, the first press-fitting portion7and the press-fitting portion intermediate portion15of the first resin bracket3are inserted into the press-fitted portion intermediate portion17of the second resin bracket5in this order.

During the period from the installation preparation state to the installation end state through the installation halfway state, the first press-fitting portion7of the first resin bracket3is inserted into the first press-fitted portion11of the second resin bracket5.

Here, the first press-fitting portion7, the press-fitting portion intermediate portion15, and the second press-fitting portion9of the first resin bracket3will be described in more detail. The cross-sectional shape of the first press-fitting portion7in a plane perpendicular to the height direction is a certain shape. The cross-sectional shape of the second press-fitting portion9in a plane perpendicular to the height direction is also in a certain shape. However, when viewed in the height direction, the first press-fitting portion7is accommodated inside the second press-fitting portion9.

In some cases, a part of the outer periphery of the first press-fitting portion7overlaps with a part of the outer periphery of the second press-fitting portion9in a state where the first press-fitting portion7is accommodated inside the second press-fitting portion9in the height direction.

The cross-sectional shape of the press-fitting portion intermediate portion15formed by a plane perpendicular to the height direction is changed to gradually increase from the first press-fitting portion7toward the second press-fitting portion9while maintaining a substantially similar shape. However, when the cross-sectional shape of the press-fitting portion intermediate portion15in the plane perpendicular to the height direction is viewed in the first direction, the cross-sectional shape of any portion is within the region between the outer periphery of the second press-fitting portion9and the outer periphery of the first press-fitting portion7.

The state where the cross section of the press-fitting portion intermediate portion15in the height direction is within an area surrounded by the outer periphery of the second press-fitting portion9and the outer periphery of the first press-fitting portion7will be described. In this state, a part of the outer periphery of the cross section of the press-fitting portion intermediate portion15may overlap at least one of a part of the outer periphery of the second press-fitting portion9and a part of the outer periphery of the first press-fitting portion7.

When viewed in the height direction, a cross section of the press-fitting portion intermediate portion15at the boundary between the first press-fitting portion7and the press-fitting portion intermediate portion15overlaps with the cross section of the first press-fitting portion7. When viewed in the height direction, a cross section of the press-fitting portion intermediate portion15at the boundary between the second press-fitting portion9and the press-fitting portion intermediate portion15overlaps with the cross section of the second press-fitting portion9.

The first press-fitted portion11, the press-fitted portion intermediate portion17, and the second press-fitted portion13of the second resin bracket5will be described. The cross-sectional shape of the first press-fitted portion11in a plane perpendicular to the height direction is slightly smaller than that of the first press-fitting portion7, and has a certain shape similar to that of the first press-fitting portion7. Since the cross-sectional shape of the first press-fitted portion11is slightly smaller than that of the first press-fitting portion7, a press-fitting margin is secured.

The cross-sectional shape of the second press-fitted portion13in a plane perpendicular to the height direction is slightly smaller than that of the second press-fitting portion9, and has a certain shape similar to that of the second press-fitting portion9. Since the shape of the second press-fitted portion13is slightly smaller than that of the second press-fitting portion9, a press-fitting margin is secured. When viewed in the height direction, the second press-fitted portion13is accommodated inside the first press-fitted portion11.

Note that in a state where the second press-fitted portion13is accommodated inside the first press-fitted portion11when viewed in the height direction, a part of the first press-fitted portion11may overlap with a part of the outer periphery of the second press-fitted portion13.

The cross-sectional shape of the press-fitted portion intermediate portion17in a plane perpendicular to the height direction is changed so as to gradually increase from the first press-fitted portion11toward the second press-fitted portion13while maintaining a substantially similar shape. However, when the cross-sectional shape of the press-fitted portion intermediate portion17formed by a plane orthogonal to the height direction is viewed in the height direction, the cross-sectional shape of any portion is contained in an area surrounded by the outer periphery of the second press-fitted portion13and the outer periphery of the first press-fitted portion11.

A state will be described in which the cross section of the press-fitted portion intermediate portion17is contained within an area surrounded by the outer periphery of the second press-fitted portion13and the outer periphery of the first press-fitted portion11. In this state, in some cases, a part of the outer periphery of the cross section of the press-fitted portion intermediate portion17overlaps at least one of a part of the outer periphery of the second press-fitted portion13and a part of the outer periphery of the first press-fitted portion11.

When viewed in the height direction, the cross section of the press-fitted portion intermediate portion17at the boundary between the first press-fitted portion11and the press-fitted portion intermediate portion17overlaps with the cross section of the first press-fitted portion11. When viewed in the height direction, the cross sections of the press-fitted portion intermediate portion17at the boundary between the second press-fitted portion13and the press-fitted portion intermediate portion17overlaps with the cross section of the second press-fitted portion13.

When viewed in the height direction, the second press-fitted portion13is slightly larger than the first press-fitting portion7, and has a certain shape similar to the first press-fitting portion7. The second press-fitted portion13has a shape similar to that of the first press-fitting portion7and is slightly larger than that of the first press-fitting portion7, so that a guide is provided in the installation halfway state.

As illustrated inFIGS.2and4, when viewed in the height direction, each of the first press-fitting portion7, the second press-fitting portion9, the first press-fitted portion11, and the second press-fitted portion13is formed in a “T” shape. That is, the first press-fitting portion7and the second press-fitting portion9form a T-shaped guide rail. The first press-fitted portion11and the second press-fitted portion13form a T-shaped guide groove.

The first press-fitting portion7, the second press-fitting portion9, the first press-fitted portion11, and the second press-fitted portion13are symmetrical with respect to a center plane C1. The center plane C1is a plane perpendicular to the length direction and includes the centers of the first press-fitting portion7, the second press-fitting portion9, the first press-fitted portion11, and the second press-fitted portion13.

As illustrated inFIG.2, the first press-fitting portion7includes a pair of first press-fitting portion first planes (two planes)25(25A,25B) separated from each other in the length direction. The first press-fitting portion7includes a pair of first press-fitting portion second planes (two planes)27(27A,27B) separated from each other in the length direction. The pair of first press-fitting portion first planes25and the pair of first press-fitting portion second planes27are positioned different from each other in the width direction.

The first press-fitting portion first planes25and the first press-fitting portion second planes27are orthogonal to the length direction. The distance between the pair of first press-fitting portion first planes25A,25B (distance in the length direction) is larger than the distance between the pair of first press-fitting portion second planes27A,27B (distance in the length direction).

The first press-fitting portion7includes two pairs of first press-fitting portion third planes29(29A,29B,29C,29D).

A first pair of first press-fitting portion third planes29A,29B and a second pair of first press-fitting portion third planes29C,29D are separated from each other in the length direction.

The first pair of first press-fitting portion third planes29A,29B are positioned on the first end side which is one end side in the length direction. The second pair of first press-fitting portion third planes29C,29D are positioned on the second end side which is the other end side in the length direction.

The first pair of first press-fitting portion third planes (two planes)29A,29B are separated from each other in the width direction. The second pair of first press-fitting portion third planes (two planes)29C,29D are separated from each other in the width direction.

The first press-fitting portion third planes29are provided with four, and all of the four first press-fitting portion third planes29are orthogonal to the second direction (length direction).

Among the four planes29A,29B,29C,29D constituting the first press-fitting portion third planes, two planes29A,29C exist on the same plane (first plane). In addition, among the four planes29A,29B,29C,29D constituting the first press-fitting portion third planes, the remaining two planes29B,29D are also on the other same plane (second plane). However, the first plane and the second plane are separated by a predetermined distance in the width direction.

As illustrated inFIG.4, the second press-fitting portion9includes a pair of second press-fitting portion first planes (two planes)31(31A,31B) separated from each other in the length direction. The second press-fitting portion9includes a pair of second press-fitting portion second planes (two planes)33(33A,33B) separated from each other in the length direction.

The second press-fitting portion first planes31and the second press-fitting portion second planes33are orthogonal to the length direction. The distance between the pair of second press-fitting portion first planes31A,31B (distance in the length direction) is larger than the distance between the pair of second press-fitting portion second planes33A,33B (distance in the length direction).

The second press-fitting portion9includes two pairs of second press-fitting portion third planes35(35A,35B,35C,35D).

Of the two pairs of second press-fitting portion third planes35, a first pair of second press-fitting portion third planes35A,35B and a second pair of second press-fitting portion third planes35C,35D are separated from each other in the length direction.

The first pair of second press-fitting portion third planes35A,35B are positioned on the first end side which is one end side in the length direction, and the second pair of second press-fitting portion third planes35C,35D are positioned on the second end side which is the other end side in the length direction.

The first pair of second press-fitting portion third planes (two planes)35A,35B are separated from each other in the width direction. The second pair of second press-fitting portion third planes (two planes)35C,35D are also separated from each other in the width direction.

The second press-fitting portion third planes35are provided with four, and all of the four second press-fitting portion third planes35are orthogonal to the length direction.

Among the four planes35A,35B,35C,35D constituting the second press-fitting portion third planes, two planes35A,35C exist on the same plane (first plane). In addition, among the four planes35A,35B,35C,35D constituting the second press-fitting portion third plane, the remaining two planes35B,35D also exist on the other same plane (second plane). The first plane and the second plane are separated by a predetermined distance in the width direction.

As illustrated inFIG.2, the first press-fitted portion11includes a pair of first press-fitted portion first planes (two planes)37(37A,37B) separated from each other in the length direction. The first press-fitted portion11includes a pair of first press-fitted portion second planes (two planes)39(39A,39B) separated from each other in the length direction.

The first press-fitted portion first planes37and the first press-fitted portion second planes39are orthogonal to the length direction. The distance between the pair of first press-fitted portion first planes37A,37B (distance in the length direction) is larger than the distance between the pair of first press-fitted portion second planes39A,39B (distance in the length direction).

The first press-fitted portion11includes two pairs of first press-fitted portion third planes41(41A,41B,41C,41D).

Of the two pairs of the first press-fitted portion third planes41, a first pair of first press-fitted portion third planes41A,41B and a second pair of first press-fitted portion third planes41C,41D are separated from each other in the length direction.

The first pair of first press-fitted portion third planes41A,41B are positioned on the first end side which is one end side in the length direction, and the second pair of first press-fitted portion third planes41C,41D are positioned on the second end side which is the other end side in the length direction.

The first pair of first press-fitted portion third planes (two planes)41A,41B are separated from each other in the width direction. The second pair of first press-fitted portion third planes (two planes)41C,41D are also separated from each other in the width direction.

The first press-fitted portion third planes41are provided with four, and all of the four first press-fitted portion third planes41are orthogonal to the length direction.

Among the four planes41A,41B,41C,41D constituting the first press-fitted portion third planes, two planes41A,41C exist on the same plane (first plane). In addition, among the four planes41A,41B,41C,41D constituting the first press-fitted portion third planes, the remaining two planes41B,41D are also on the other same plane (second plane). The first plane and the second plane are separated by a predetermined distance in the width direction.

As illustrated inFIG.4, the second press-fitted portion13includes a pair of second press-fitted portion first planes (two planes)43(43A,43B) separated from each other in the length direction. The first press-fitted portion11includes a pair of second press-fitted portion second planes (two planes)45(45A,45B) separated from each other in the length direction.

The second press-fitted portion first planes43and the second press-fitted part second planes45are orthogonal to the length direction. The distance between the pair of second press-fitted portion first planes43A,43B (distance in the length direction) is larger than the distance between the pair of second press-fitted portion second planes45A,45B (distance in the length direction).

The second press-fitted portion13includes two pairs of second press-fitted portion third planes47(47A,47B,47C,47D).

Among the two pairs of the second press-fitted portion third planes47, a first pair of second press-fitted portion third planes47A,47B and a second pair of second press-fitted portion third planes47C,47D are separated from each other in the length direction.

The first pair of second press-fitted portion third planes47A,47B are positioned on the first end side which is one end side in the length direction, and the second pair of second press-fitted portion third planes47C,47D are positioned on the second end side which is the other end side in the length direction.

The first pair of second press-fitted portion third planes (two planes)47A,47B are separated from each other in the width direction. The second pair of second press-fitted portion third planes (two planes)47C,47D are also separated from each other in the width direction.

The second press-fitted portion third planes47are provided with four, and all of the four second press-fitted portion third planes47are orthogonal to the length direction.

Among the four planes47A,47B,47C,47D constituting the second press-fitted portion third plane, two planes47A,47C exist on the same plane (first Plane). In addition, among the four planes47A,47B,47C,47D constituting the second press-fitted portion third plane, the remaining two planes47B and47D are also on the other same plane (second plane). However, the first plane and the second plane are separated by a predetermined distance in the width direction.

As illustrated inFIG.2, in the installation end state, the first press-fitting portion first plane25A and the first press-fitted portion first plane37A are in surface contact with each other with a biasing force. In the installation end state, the first press-fitting portion first plane25B and the first press-fitted portion first plane37B are in surface contact with each other with a biasing force.

In the installation end state, the first press-fitting portion second plane27A and the first press-fitted portion second plane39A are in surface contact with each other with a biasing force. In the installation end state, the first press-fitting portion second plane27B and the first press-fitted portion second plane39B are in surface contact with each other with a biasing force.

With such structures, as described in the first fitting mode, the first resin bracket3and the second resin bracket5are fitted at two places in a predetermined direction (the width direction) in an interference-fitting state. A fitting of a first place of the two places is achieved by the first press-fitting portion first planes25and the first press-fitted portion first planes37. A fitting of a second place of the two places is achieved by the first press-fitting portion second planes27and the first press-fitted portion second planes39.

In the installation end state, the first press-fitting portion third plane29A and the first press-fitted portion third plane41A are in surface contact with each other with a biasing force. In the installation end state, the first press-fitting portion third plane29B and the first press-fitted portion third plane41B are in surface contact with each other with a biasing force. In the installation end state, the first press-fitting portion third plane29C and the first press-fitted portion third plane41C are in surface contact with each other with a biasing force. In the installed state, the first press-fitting portion third plane29D and the first press-fitted portion third plane41D are in surface contact with each other with a biasing force.

As illustrated inFIG.4, in the installation end state, the second press-fitting portion first plane31A and the second press-fitted portion first plane43A are in surface contact with each other with a biasing force. In the installation end state, the second press-fitting portion first plane31B and the second press-fitted portion first plane43B are in surface contact with each other with a biasing force.

In the installation end state, the second press-fitting portion second plane33A and the second press-fitted portion second plane45A are in surface contact with each other with a biasing force. In the installation end state, the second press-fitting portion second plane33B and the second press-fitted portion second plane45B are in surface contact with each other with a biasing force.

With such structures, as described in the second fitting mode, the first resin bracket3and the second resin bracket5are fitted at two places in a predetermined direction (the width direction) in an interference-fitting state. A fitting of a first place of the two places is achieved by the second press-fitting portion first planes31and the second press-fitted portion first planes43. A fitting of a second place of the two places is achieved by the second press-fitting portion second planes33and the second press-fitted portion second planes45.

In the installation end state, the second press-fitting portion third plane35A and the second press-fitted portion third plane47A are in surface contact with each other with a biasing force. In the installation end state, the second press-fitting portion third plane35B and the second press-fitted portion third plane47B are in surface contact with each other with a biasing force. In the installation end state, the second press-fitting portion third plane35C and the second press-fitted portion third plane47C are in surface contact with each other with a biasing force. In the installation end state, the second press-fitting portion third plane35D and the second press-fitted portion third plane47D are in surface contact with each other with a biasing force.

Here, a dimension in the width direction between an end face of the first resin bracket body portion19and the first press-fitting portion third planes29A,29C in the installation preparation state is represented by reference numeral L2a(seeFIG.2). A dimension in the width direction between the end face of the first resin bracket body portion19and the second press-fitting portion third planes35A,35C in the installation preparation state is represented by reference numeral L4a(seeFIG.4). In the installation preparation state, the dimension L2aand the dimension L4aare equal to each other. In other words, in the installation preparation state, the first press-fitting portion third plane29A, the first press-fitting portion third plane29C, the second press-fitting portion third plane35A, and the second press-fitting portion third plane35C of the first member3exist on one plane.

In the installation preparation state, the first press-fitted portion third plane41A, the first press-fitted portion third plane41C, the second press-fitted portion third plane47A, and the second press-fitted portion third plane47C of the second member5exist on one plane.

Therefore, the press-fitting in the member junction structure1is performed by using the first press-fitting portion third plane29A or the like as a reference plane in the width direction. As a result, a dimension indicated by reference sign L4binFIG.4is slightly larger than a dimension indicated by reference sign L2binFIG.2.

Next, the installation of the second resin bracket5on the first resin bracket3will be described.

First, the position and the posture of the second resin bracket5with respect to the first resin bracket3are appropriately adjusted to the above-described installation preparation state.

In the installation preparation state, the second resin bracket5is moved downward by a predetermined distance with respect to the first resin bracket3, for example, by hand, whereby the above-described installation halfway state is established (seeFIG.8B). From the state illustrated inFIG.8B, the second resin bracket5is further moved downward with respect to the first resin bracket3, for example, by hand, so that the dimension L8becomes “0”. When the dimension L8becomes “0”, the second resin bracket5cannot be further moved downward with respect to the first resin bracket3by a bare hand.

Therefore, when the second resin bracket5is further moved downward by a predetermined distance with respect to the first resin bracket3by using a dedicated press machine or a general-purpose press machine, the installation end state is completed as described above.

In the member junction structure1according to the embodiment, in the installation halfway state, the first press-fitting portion7is inserted into the second press-fitted portion13to provide a guide for installing the second member5in the first member3. In the installation end state, the first press-fitting portion7is press-fitted into the first press-fitted portion11, and the second press-fitting portion9is press-fitted into the second press-fitted portion13.

With such configurations, it is possible to sufficiently secure the amount of the temporary press-fitting even when the temporary press fitting is performed in the installation halfway state by a bare hand operation. By securing a sufficient amount of the temporary press-fitting, the possibility that the second member5is inclined to the first member3can be eliminated. Further, even if a general-purpose press machine is used without using a dedicated press machine or the like, the press-fitting can be easily performed and the installation end state can be completed.

Further, since the oblique deep guide surface is not provided and the first press-fitting portion7is press-fitted into the first press-fitted portion11and the second press-fitting portion9is press-fitted into the second press-fitted portion13, the joining strength of the first member3and the second member5can be secured after the press-fitting (Installation end status). The looseness between the first member3and the second member5in the installation end state can be eliminated.

On the other hand, as illustrated inFIGS.11A to11D, in a member junction structure301according to a comparative example, when a first resin bracket303and a second resin bracket305are joined to each other, a press-fitting portion303of the first resin bracket307is press-fitted into a press-fitted portion309of the second resin bracket305.

However, in the member junction structure301according to the comparative example, since a large force is required to press-fit the press-fitting portion303into the press-fitted portion309, it is difficult to press-fit by bare hands without using a dedicated press machine. Therefore, it is necessary to temporarily fit by bare hands, and then the main press-fitting is performed by using a dedicated press machine to finish the press-fitting.

However, if the press-fitting amount in the temporary press-fitting is insufficient, there is a risk that the second resin bracket305is inclined obliquely (see arrow A11binFIG.11C) when the main press-fitting is performed by using a dedicated press machine or the like (see arrow A11ainFIG.11C).

Therefore, as illustrated inFIG.11D, by forming oblique deep guide surfaces (long guide faces in insertion direction)311at the end of the press-fitted portion309of the second resin bracket305, the press-fitting amount in the temporary press-fitting can be sufficiently secured.

However, if the deep guide surfaces311are formed, when the first resin bracket303and the second resin bracket305are press-fitted with each other, the area of the contact surface between the press-fitting portion307of the first resin bracket303and the press-fitted portion309of the second resin bracket305is reduced. As a result, the joining strength of the first resin bracket303and the second resin bracket305becomes weak, and there is a possibility that rattling occurs between the first resin bracket303and the second resin bracket305.

Therefore, in the member junction structure1according to the embodiment, the first member3and the second member5are press-fitted in an interference-fitting state at two places in a predetermined direction after the second member5is completely installed in the first member3. Thus, the joining strength between the first member3and the second member5can be further enhanced.

Further, in the member junction structure1according to the embodiment, since the first member3and the second member5are fitted to each other in an interference-fitting state at a plurality of places in the length direction, the joining strength of the first member3and the second member5in the length direction can be further enhanced. That is, the resistance against the rotational moment about the axis extending in the width direction becomes large.

In the member junction structure1according to the embodiment, the second member5is positioned with respect to the first member3in the direction orthogonal to the moving direction of the second member5by the guide in the installation halfway state. Thus, the posture of the second member5with respect to the first member3in the installation halfway state can be made substantially constant, and the temporary press-fitting operation can be facilitated.

Further, in the member junction structure1according to the embodiment, the press-fitting portion intermediate portion15and the press-fitted portion intermediate portion17are provided, and the press-fitted portion intermediate portion17is slightly separated from the press-fitting portion intermediate portion15in the installation end state. Thus, the press-fitting portions7,9of the first member3and the press-fitted portions11,13of the second member5are in contact with each other only at both ends in the height direction in the installation end state. In addition, it is possible to increase the resistance to the rotational moment among the joining strengths of the first member3and the second member5in the installation end state.

In the above description, the first press-fitting portion7and the second press-fitting portion9form a T-shaped guide rail, and the first press-fitted portion11and the second press-fitted portion13form a T-shaped guide groove.

Alternatively, as in a first modification illustrated inFIG.9, the first press-fitting portion7and the second press-fitting portion9may form an isosceles trapezoidal guide rail, and the first press-fitted portion11and the second press-fitted portion13may form an isosceles trapezoidal guide groove (dovetail groove).

Further, as illustrated inFIGS.10A to10D, the press-fitting portion may be formed in a columnar shape, and the press-fitting portion may be formed in a hole. In a member junction structure1according to a second modification illustrated inFIGS.10A and10B, the first press-fitting portion7, the second press-fitting portion9, and the press-fitting portion intermediate portion15are formed in a circular columnar shape, and the first press-fitted portion11, the second press-fitted portion13, and the press-fitted portion intermediate portion17are formed in a circular columnar hole.

In a member junction structure1according to a third modification illustrated inFIGS.10C and10D, the first press-fitting portion7, the second press-fitting portion9, and the press-fitting portion intermediate portion15are formed in a square columnar shape, and the first press-fitted portion11, the second press-fitted portion13, and the press-fitted portion intermediate portion17are formed in a square columnar hole.

Incidentally, the member junction structure1according to the embodiment is adopted, for example, in an electric junction box such as a fuse box, a relay box, or a junction box. That is, the electric junction box is provided with the member junction structure1(by using the resin bracket press-fitting structure1). When the member junction structure1is adopted by the fuse box, the first member3becomes a fuse box body portion to which the fuse is installed, and the second member5becomes a cover to cover the fuse or the like by being installed in the fuse box body portion.

When the member junction structure1is adopted by the relay box, the first member3becomes a relay box body portion where the relay is installed, and the second member5becomes a cover for covering the relay or the like by being installed in the relay box body portion. When the member junction structure1is adopted by the junction box, the first member3becomes a junction box body portion to which a terminal is connected, and the second member5becomes a cover for covering wiring or the like provided in the junction box body portion.

Further, the resin bracket press-fitting structure1according to the embodiment can be adopted in any product using a bracket such as an ECU (engine control unit), a BTU (battery unit), a voltage sensor, or a current sensor in addition to the fuse box or the like described above.

Although the embodiment has been described above, the embodiment is not limited thereto, and various modifications can be made within the scope of the gist of the present embodiment.