Fixing structure of electronic component and in-vehicle charger

A fixing structure of an electronic component includes a fixing member configured to fix an electronic component while pressing the electronic component against a wall surface of a housing in a pressing direction; and a fastened portion which is provided at a position away from the wall surface of the housing and to which the fixing member is fastened and fixed. The fixing member includes a fixing portion that is fastened and fixed to the fastened portion, a pressing portion that extends from the fixing portion toward the electronic component and is configured to press the electronic component against the wall surface in the pressing direction, and an engaging portion which is provided at the fixing portion. The fastened portion includes an engaged portion that is engaged with the engaging portion, and is configured to limit movement of the fixing portion in a direction opposite to the pressing direction.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based on and claims priority under 35 USC 119 from Japanese Patent Application No. 2021-142158 filed on Sep. 1, 2021, the contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a fixing structure of an electronic component and an in-vehicle charger.

BACKGROUND ART

As a fixing structure of an electronic component, it is known that a plurality of arranged heat-generating electronic components are sandwiched between a heat-dissipation element and an elastic clip, so that the plurality of heat-generating electronic components and the heat-dissipation element are closely bonded to each other as disclosed, for example, in JP2017-108121A and JP2016-167425A. JP2017-108121A describes a structure in which by tightening the elastic clip to the heat-dissipation element with a screw between the heat-generating electronic component and the heat-generating electronic component, the plurality of heat-generating electronic components are pressed against the heat-dissipation element. JP2017-108121A and JP2016-167425A describe a structure in which by tightening the elastic clip to the heat-dissipation element with the screw in lower sides of the plurality of heat-generating electronic components, the plurality of heat-generating electronic components are pressed against the heat-dissipation element.

In the structure in which the elastic clip is fastened to the heat-dissipation element with the screw between the heat-generating electronic component and the heat-generating electronic component, it is necessary to provide a space for the screw, a fastened portion, or the like between the heat-generating electronic component and the heat-generating electronic component, and thus a dimension in a pitch direction (arrangement direction of the plurality of heat-generating electronic components) of an installation space for the plurality of heat-generating electronic components becomes large. In addition, a tightening force of a bolt changes depending on a tightening margin of the screw.

In the structure in which the elastic clip is fastened to the heat-dissipation element with the screw in the lower sides of the heat-generating electronic components, it is necessary to provide a space for the screw, a fastened portion, or the like in the lower side of the heat-generating electronic component, and thus a dimension in a height direction of the installation space for the plurality of heat-generating electronic components becomes large.

SUMMARY OF INVENTION

The present disclosure provides a fixing structure of an electronic component which can reliably fix the electronic component to a wall surface of a housing and can prevent an increase in a dimension of an installation space for the electronic component in the wall surface of the housing, and to provide an in-vehicle charger.

A fixing structure of an electronic component includes a fixing member configured to fix at least one electronic component while pressing the at least one electronic component against a wall surface of a housing in a pressing direction, and a fastened portion which is provided at a position away from the wall surface of the housing and to which the fixing member is fastened and fixed. The fixing member includes a fixing portion that is fastened and fixed to the fastened portion in a fastening direction that intersects the pressing direction, at least one pressing portion that extends from the fixing portion toward the at least one electronic component, the at least one pressing portion being configured to press the at least one electronic component against the wall surface in the pressing direction, and at least one engaging portion which is provided at the fixing portion. The fastened portion includes at least one engaged portion that is engaged with the at least one engaging portion, the at least one engaged portion being configured, in cooperation with the at least one engaging portion, to limit movement of the fixing portion in a direction opposite to the pressing direction.

An in-vehicle charger includes a housing, an electronic component that is fixed to a wall surface of the housing, a fixing member that fixes the electronic component while pressing the electronic component against the wall surface in a pressing direction, and a fastened portion which is provided at a position away from the wall surface of the housing and to which the fixing member is fastened and fixed. The fixing member includes a fixing portion that is fastened and fixed to the fastened portion in a fastening direction that intersects the pressing direction, a pressing portion that extends from the fixing portion to the electronic component and presses the electronic component against the wall surface in the pressing direction, and an engaging portion which is provided at the fixing portion. The fastened portion includes an engaged portion that is engaged with the engaging portion, the engaged portion being configured, in cooperation with the engaging portion, to limit movement of the fixing portion in a direction opposite to the pressing direction.

DESCRIPTION OF EMBODIMENTS

Hereinafter, the present disclosure will be described according to preferred embodiments. The present disclosure is not limited to the embodiments to be described below, and can be changed as appropriate without departing from the gist of the present disclosure. In the embodiments to be described below, some configurations are not illustrated or described, but a known or well-known technique is applied as appropriate to details of an omitted technique within a range where no contradiction occurs to contents to be described below.

FIG.1is a perspective view showing a fixing structure10of electronic components1according to an embodiment of the present disclosure. The fixing structure10shown inFIG.1fixes the electronic components1attached to a wall surface211of a housing21of an in-vehicle charger2. The fixing structure10includes fixing members100and bases220to which the fixing members100are fastened and fixed.

The electronic component1is an electronic component that self-heats when energized, and is, for example, a field effect transistor (FET) or a discrete component. The electronic component1includes a thin rectangular parallelepiped main body portion11which is a heat-generating portion, and a plurality of lead wires12. The plurality of lead wires12are connected to a circuit board (not shown).

A heat-dissipation sheet3is attached to the wall surface211of the housing21for heat dissipation and insulation of the electronic component1. The electronic component1is fixed in a state of being pressed against the wall surface211of the housing21via the heat-dissipation sheet3by the fixing member1M. Further, a cooling water channel (not shown) is provided on the wall surface211of the housing21to promote the heat dissipation of the electronic component1.

In the present embodiment, the plurality of electronic components1are arranged at equal intervals along a left-right direction (direction orthogonal to a height direction) of the wall surface211of the housing21. Here, a distance between the electronic component1and the electronic component1is set so narrow that a screw and a bolt cannot be inserted. In each electronic component1, one surface (heat-dissipation surface) of the main body portion11is in surface contact with the heat-dissipation sheet3, and the lead wires12are arranged so as to extend upward from the main body portion11.

A flange212projects laterally from the wall surface211of the housing21, and the plurality of bases220are provided on an upper surface of the flange212. The plurality of bases220are arranged at equal intervals along an arrangement direction of the plurality of electronic components1. Each base220includes a rectangular upper surface220A whose longitudinal direction is the arrangement direction of the plurality of electronic components1. Here, each of the plurality of bases220is provided corresponding to the two electronic components1.

FIG.2is a perspective view showing the fixing structure10ofFIG.1with the fixing member100not shown. As shown inFIGS.1and2, the base220extends parallel to lower end portions of the two electronic components1in the vicinity of the lower end portions (each end portion on an opposite side of the lead wires12side). The fixing member100is fastened and fixed to the upper surface220A of the base220by a screw4. A pair of bosses221are formed on the upper surface220A of the base220, and a screw hole222is formed in a central portion of the base220in the longitudinal direction.

FIG.3is a perspective view showing the fixing member100of the fixing structure10ofFIG.1. As shown inFIGS.1and3, the fixing member100includes a fixing portion110and a pair of pressing portions120. The fixing portion110is formed in a shape of a rectangular plate whose longitudinal direction is the arrangement direction of the electronic components1. An insertion hole111for the screw4is formed in a central portion of the fixing portion110in the longitudinal direction. The fixing portion110is fastened and fixed to the upper surface220A of the base220by screwing the screw4inserted into the insertion hole111into the screw hole222(seeFIG.2).

A semicircular shape of a fastened portion112is formed at the central portion of the fixing portion110in the longitudinal direction. The fastened portion112is formed so as to project toward an electronic component1side at the central portion in the longitudinal direction and one end portion in a width direction (end portion on the electronic component1side) of the fixing portion110. A center of curvature of the fastened portion112coincides with a center of the screw hole222.

A pair of U-shaped grooves113are formed at the other end portion (end portion opposite to the electronic component1side) of the fixing portion110in the width direction. The pair of grooves113are provided in one end side and the other end side in the longitudinal direction of the fixing portion110. Centers of curvature in deep portions of the pair of grooves113are provided in the central portion of the fixing portion110in the width direction.

FIG.4is a plan view showing the fixing structure10ofFIG.1. As shown inFIGS.1and4, the pair of bosses221are provided on one end side and the other end side of the upper surface220A of the base220in the longitudinal direction. The pair of bosses221are provided corresponding to the pair of grooves113, and a center position of each boss221coincides with a position of the center of curvature in the deep portion of each groove113, and each boss221engages with the deep portion of the groove113.

The pair of pressing portions120are leaf springs. The pair of pressing portions120are arranged side by side in the arrangement direction of the electronic components1. The fastened portion112is provided between the pair of pressing portions120. Each pressing portion120is arranged so as to face each electronic component1.

Each of the pair of pressing portions120stands up in a state of being inclined toward the electronic component1side from one end portion (end portion on the electronic component1side) of the fixing portion110in the width direction. A tip end side of the pressing portion120is refracted to a side away from the electronic component1, and a refracting portion121of the pressing portion120is in contact with a central portion of the main body portion11of the electronic component1. Accordingly, an elastic force of the pressing portion120, which is the leaf spring, acts as a force for pressing the electronic component1against the wall surface211of the housing21, and the electronic component1is fixed in a state of being pressed against the wall surface211by the pressing portion120.

FIG.5is a side view showing the fixing structure10ofFIG.1. As shown inFIG.5, in the fixing structure10, a pressing force acts on the electronic component1and the wall surface211from the pressing portion120, whereas a reaction force Y with respect to the pressing force acts on the fixing portion110via the pressing portion120. The reaction force Y acts in a direction orthogonal to a fastening direction of the screw4, but by engaging the pair of bosses221and the pair of grooves113as shown inFIG.1, movement of the fixing portion110due to the reaction force Y in a direction opposite to the pressing direction is limited. Rotation of the fixing portion110fastened and fixed to the upper surface220A of the base220around the screw4is limited by the pair of bosses221and the pair of grooves113.

Here, a comparative example in which the fixing portion110is fastened and fixed to the wall surface211by the screw4as in the above prior art will be examined. In the comparative example, a screw hole must be formed around the electronic component1in the wall surface211to fasten and fix the fixing portion110, and an area of the wall surface211is expanded by a space for mounting the fixing portion110. When the fixing portion110is mounted at the lower side of the electronic component1in the wall surface211, a height dimension of the wall surface211is increased, and the housing21is enlarged in the height direction. Meanwhile, when the fixing portion110is mounted between the electronic component1and the electronic component1in the wall surface211, a dimension of the wall surface211in a lateral direction (arrangement direction of the electronic components1) is expanded, and the housing21is enlarged in the lateral direction.

Meanwhile, in the fixing structure10of the electronic components1of the present embodiment, the fixing portion110of the fixing member100is fastened and fixed to the base220provided at a position separated from the wall surface211in the direction opposite to the pressing direction. The fixing portion110is fastened and fixed to the base220by the screw4in the fastening direction intersecting the pressing direction. Accordingly, the space for mounting the fixing portion110can be eliminated from the lower side of the electronic component1in the wall surface211or between the electronic component1and the electronic component1. Therefore, as compared with the above comparative example, the height dimension and the dimension in the lateral direction of the wall surface211can be suppressed, and the housing21can be prevented from being enlarged in the height direction and the lateral direction.

In addition, in the fixing structure10of the electronic component1of the present embodiment, cooperation between the grooves113provided in the fixing portion110and the bosses221provided in the base220can limit the movement of the fixing portion110by the reaction force Y in the direction opposite to the pressing direction. Therefore, the electronic component1can be reliably fixed in the state of being pressed against the wall surface211by the fixing member100, and a heat dissipation effect of the electronic component1can be reliably realized.

In the fixing structure10of the electronic components1of the present embodiment, the pair of pressing portions120are arranged side by side in the arrangement direction of the electronic components1, and each pressing portion120is provided corresponding to each electronic component1. Here, since a width of each pressing portion120is narrower than a width of the main body portion11of each electronic component1, the fastened portion112of the fixing portion110between the pair of pressing portions120can be provided without unnecessarily widening the distance between the electronic component1and the electronic component1. By fastening and fixing the fastened portion112to the base220existing at the position separated from the wall surface211, the fixing member100including the pair of pressing portions120is mounted to the housing21without unnecessarily widening the distance between the electronic component1and the electronic component1.

In the fixing structure10of the electronic components1of the present embodiment, the pair of grooves113and the pair of bosses221are arranged side by side in the arrangement direction of the electronic components1. Accordingly, rotation of the pressing portion120around the screw4can be limited regardless of a positional relationship of the groove113and the boss221with respect to the pressing portion120and the screw4.

FIG.6is a plan view showing a fixing structure10A of the electronic components1according to another embodiment of the present disclosure. As shown inFIG.6, the fixing stricture10A of the present embodiment includes a round hole113A and an elongated hole113B instead of the pair of grooves113of the above embodiment. The round hole113A positions one boss221relatively in two directions of the arrangement direction and the pressing direction of the electronic components1. Meanwhile, the elongated hole113B positions the other boss221relatively in one direction of the pressing direction. Accordingly, the fixing member100is positioned in the two directions of the arrangement direction and the pressing direction of the electronic components1.

FIG.7is a plan view showing a fixing structure10B of the electronic components1according to another embodiment of the present disclosure. As shown inFIG.7, in the fixing structure10B of the present embodiment, one boss221is provided on one base220, and one round hole113A is provided on one fixing portion110. The round hole113A positions the boss221relatively in the two directions of the arrangement direction and the pressing direction of the electronic components1.

Here, if the screw4is a right-handed screw, a rotational force in a clockwise direction acts on the fixing portion110when the screw4is tightened, and if the screw4is a left-handed screw, a rotational force in a counterclockwise direction acts on the fixing portion110when the screw4is tightened. Meanwhile, the round hole113A and the boss221limit the rotation of the fixing portion110around the screw4in the clockwise direction and the counterclockwise direction. Therefore, the rotation of the fixing portion110is prevented when the screw4is tightened.

FIG.8is a plan view showing a fixing structure10C of the electronic components1according to another embodiment of the present disclosure. As shown inFIG.8, in the fixing structure10C of the present embodiment, a fixing member100C includes one pressing portion120and one groove113, and one boss221is provided on one base220.

Here, the screw4is a right-handed screw, and the rotational force in the clockwise direction acts on the fixing portion110when the screw4is tightened. Meanwhile, the groove113and the boss221are provided at positions that limit the rotation of the fixing portion110around the screw4in the clockwise direction. Therefore, the rotation of the fixing portion110is prevented when the screw4is tightened.

FIG.9is a side view showing a fixing structure10D of the electronic components1according to another embodiment of the present disclosure. As shown inFIG.9, in the fixing structure10D of the present embodiment, the upper surface220A of the base220, which is horizontal in the above embodiment, is inclined. Here, the upper surface220A is inclined such that a height becomes lower as a distance from the electronic component1side increases. Accordingly, a posture of the screw4, which is vertical in the above embodiment, is changed to a posture in which a head is inclined toward a side away from the electronic component1. Therefore, when the screw4is tightened, a fastening tool such as a screwdriver and the electronic component1are less likely to interfere with each other, and a workability of a fastening work of the screw4is improved.

Although the present disclosure has been described based on the embodiments, the present disclosure is not limited to the embodiments described above. The present disclosure may be modified without departing from the gist of the present disclosure, or known and well-known techniques may be combined as appropriate. For example, in the above embodiments, the boss221is provided at the base220, and the groove113, the round hole113A, and the elongated hole113B are provided in the fixing portion110, but the boss221may be provided at the fixing portion110, and the groove113, the round hole113A, and the elongated hole113B may be provided in the base220.

In the above embodiments, the two pressing portions120are provided at one fixing member100, but three or more pressing portions120may be provided at one fixing member100. In this case, one fixing member100is provided corresponding to three or more electronic components1. Further, the number of the grooves113, the round holes113A, the elongated holes113B, and the bosses221is not limited to one or two, and may be three or more.

According to a first aspect of the present disclosure, a fixing structure (10,10A,10B,10C,10D) of an electronic component (1) includes a fixing member (100,100C) configured to fix at least one electronic component (1) while pressing the at least one electronic component (1) against a wall surface (211) of a housing (21) in a pressing direction, and a fastened portion (220) which is provided at a position away from the wall surface (211) of the housing (21) and to which the fixing member (100,100C′) is fastened and fixed. The fixing member (100,100C) includes a fixing portion (110) that is fastened and fixed to the fastened portion (220) in a fastening direction that intersects the pressing direction, at least one pressing portion (120) that extends from the fixing portion (110) toward the at least one electronic component (1), the at least one pressing portion (120) being configured to press the at least one electronic component (1) against the wall surface (211) in the pressing direction, and at least one engaging portion (113,113A,113B) which is provided at the fixing portion (110). The fastened portion (220) includes at least one engaged portion (221) that is engaged with the at least one engaging portion (113,113A,113B), the at least one engaged portion (221) being configured, in cooperation with the at least one engaging portion (113,113A,113B), to limit movement of the fixing portion (110) in a direction opposite to the pressing direction.

According to a second aspect of the present disclosure, the at least one electronic component (1) comprises a plurality of electronic components (1) arranged in an arrangement direction, the at least one pressing portion (120) comprises a plurality of pressing portions (120) arranged in the arrangement direction, and the fixing portion (110) is fastened and fixed to the fastened portion (220) between adjacent ones of the plurality of pressing portions (120).

According to a third aspect of the present disclosure, the at least one engaging portion (113,113A,113B) comprises a plurality of engaging portions (113,113A,113B) arranged in the arrangement direction, and the at least one engaged portion (221) comprises a plurality of engaged portions (221) arranged in the arrangement direction.

According to a fourth aspect of the present disclosure, an in-vehicle charger (2) includes a housing (21), an electronic component (1) that is fixed to a wall surface (211) of the housing (21), a fixing member (100,100C) that fixes the electronic component (1) while pressing the electronic component (1) against the wall surface (211) in a pressing direction, and a fastened portion (220) which is provided at a position away from the wall surface (211) of the housing (21) and to which the fixing member (100,100C) is fastened and fixed. The fixing member (100,100C) includes a fixing portion (110) that is fastened and fixed to the fastened portion (220) in a fastening direction that intersects the pressing direction, a pressing portion (120) that extends from the fixing portion (110) to the electronic component (1) and presses the electronic component (1) against the wall surface (211) in the pressing direction, and an engaging portion (113,113A,113B) which is provided at the fixing portion (110). The fastened portion (220) includes an engaged portion (221) that is engaged with the engaging portion (113,113A,113B), the engaged portion (221) being configured, in cooperation with the engaging portion (113,113A,113B), to limit movement of the fixing portion (110) in a direction opposite to the pressing direction.

According to the present disclosure, the electronic component can be reliably fixed to the wall surface of the housing, and the increase in the dimension of the installation space for the electronic component in the wall surface of the housing can be prevented.