electronic machinery

Abstract

To provide an electronic apparatus that is waterproof and easy to assemble.SOLUTION: An electronic apparatus includes a housing 2, a first member (busbar 4), and a second member (grommet 5). The first member protrudes from the hole of the housing. The second member is attached to the hole of the housing and has an insertion opening into which the first member is inserted. The second member includes a covering portion 51 that tightly covers the periphery of the tip with a gap formed at the tip of the hole, and a contact portion 52 connected to the covering portion, disposed in contact with the first member, and having a tapered tip tapered along the outer surface of the first member.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to an electronic device.

Background Art

[0002] Conventionally, for example, regarding an electronic device mounted on a vehicle, a structure is known in which a grommet is used to waterproof between a bus bar that allows a large current to flow from a substrate inside a housing to the outside of the housing and a cover.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the prior art, in such a structure, in the case of an assembly process in which a grommet is attached to a cover and then passed through a plurality of bus bars simultaneously, assembly may be difficult due to the tolerances of each component.

[0005] The present invention has been made in view of the above, and an object thereof is to provide an electronic device that can be easily assembled while having waterproof properties.

Means for Solving the Problems

[0006] In order to solve the above-described problems and achieve the object, an electronic device according to the present invention includes a housing, a first member, and a second member. The first member protrudes from a hole portion of the housing. The second member is attached to the hole portion of the housing and has an insertion port into which the first member is inserted. The second member has a covering portion that closely covers the periphery of the tip in a state where a gap is formed at the tip of the hole portion, and a contact portion that is connected to the covering portion and is disposed in contact with the first member and has a tapered shape that tapers along the outer surface of the first member at the tip.

Effects of the Invention

[0007] According to the present invention, assembly can be easily carried out while maintaining waterproof properties. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a diagram showing the mounting position of the electronic device according to the embodiment. [Figure 2] Figure 2 is a perspective view showing the external appearance of the electronic device according to this embodiment. [Figure 3] Figure 3 shows the electronic device viewed from above (positive Y-axis). [Figure 4] Figure 4 is a cross-sectional view of an electronic device. [Figure 5] Figure 5 is a cross-sectional view of the grommet. [Modes for carrying out the invention]

[0009] The embodiments of the electronic device disclosed herein will be described in detail below with reference to the attached drawings. However, the present invention is not limited to the embodiments described below.

[0010] Figure 1 is a diagram showing the mounting position of the electronic device according to the embodiment. As shown in Figure 1, the electronic device 1 according to the embodiment is mounted on the vehicle C. The electronic device 1 is, for example, an inverter that supplies power to a drive motor mounted on the vehicle C, and is positioned, for example, on the outside bottom of the vehicle C. In other words, the electronic device 1 is positioned in an exposed state on the outside of the vehicle C.

[0011] In Figure 1 and subsequent figures, a three-axis orthogonal coordinate system is shown. Specifically, the X-axis corresponds to the direction of travel (forward / backward direction) of vehicle C, with the positive side being forward and the negative side being backward. The Y-axis corresponds to the height direction of vehicle C, with the positive side being the higher side and the negative side being the lower side. The Z-axis corresponds to the width direction of vehicle C, with the positive side being the rightward direction and the negative side being the leftward direction. Note that in Figure 2 and subsequent figures, the Z-axis may not be shown; in such cases, it means that the positive and negative directions of the Z-axis are not considered.

[0012] Next, the external configuration of the electronic device 1 according to the embodiment will be described using Figures 2 and 3. Figure 2 is a perspective view showing the external appearance of the electronic device 1 according to the embodiment. Figure 3 is a view of the electronic device 1 from above (positive Y-axis side).

[0013] As shown in Figure 2, the electronic device 1 according to this embodiment has a substantially rectangular parallelepiped shape. As shown in Figure 2, the electronic device 1 comprises a housing 2, a lid 3, a busbar 4, a grommet 5, and a heat dissipation fin 6. Other components, such as the internal configuration of the electronic device 1, will be described later.

[0014] The housing 2 houses various components, such as electronic components, related to the electronic device 1. The internal structure of the housing 2 will be described later in Figure 4. The housing 2 has an opening on the top side (positive Y-axis side), and this opening is covered by the lid 3.

[0015] Furthermore, the housing 2 has multiple heat dissipation fins 6 on its lower side (negative Y-axis side) that function as a heat sink. The heat dissipation fins 6 are heat dissipation members that protrude from the outer surface 21 of the housing 2 (see Figure 4) and dissipate heat generated by the electronic components built into the housing 2 to the outside.

[0016] The lid 3 functions as a lid that closes the opening of the housing 2. By closing the opening of the housing 2, the lid 3 prevents foreign matter (such as moisture, dust, and dirt) from entering the inside of the housing 2. In this disclosure, the housing 2 and the lid 3 may be collectively referred to as the housing 2.

[0017] The bus bar 4 (an example of the first member) is a conductive member that conducts the current generated by the electronic device 1 to the drive motor mounted on the vehicle C. It is assembled so as to pass through a hole provided in the lid portion 3 (housing 2) from the inside of the housing 2 and project outward from the hole. The bus bar 4 is mounted on a substrate 7 (see FIG. 4) inside the housing 2. In the present disclosure, as shown in FIG. 2, an example in which a plurality (five) of bus bars 4 are arranged is shown.

[0018] The grommet 5 (an example of the second member) is interposed between the housing 2 (lid portion 3) and the bus bar 4, electrically insulates the bus bar 4 from the housing 2, and prevents foreign matter (such as moisture, dust, and dirt) from entering the inside of the housing 2. Specifically, as shown in FIG. 3, the grommet 5 is attached to the hole of the housing 2 (lid portion 3) and has an insertion port 50 into which the bus bar 4 is inserted. The grommet 5 is, for example, an elastic member made of a resin material or the like.

[0019] Next, the internal configuration of the electronic device 1 will be described using FIG. 4. FIG. 4 is a cross-sectional view of the electronic device 1. The cross-sectional view of FIG. 4 shows a cross-section cut along the line A-A in FIG. 3.

[0020] As shown in FIG. 4, in addition to the above-described housing 2, lid portion 3, bus bar 4, grommet 5, and heat dissipation fins 6, the electronic device 1 further includes a first substrate 7, a second substrate 8, a low-profile component 9, a high-profile component 10, and a current sensor 11.

[0021] The first substrate 7 is a power substrate, and the second substrate 8 is a control system substrate. A power substrate is a substrate through which a large current flows, and a power IC such as a switching element that supplies a large current to a load is mounted thereon. Usually, since a power IC generates a large amount of heat, it is mounted on the power substrate and not on the control system substrate. A control system substrate is a substrate on which electronic components related to a control circuit are mounted.

[0022] Low-profile components 9 and high-profile components 10 are electronic components mounted on the first substrate 7. Low-profile components 9 have a lower component height (length in the Y-axis direction in Figure 4) and generate more heat than high-profile components 10. For example, low-profile components 9 are transistors such as MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors), and high-profile components 10 are capacitors.

[0023] The low-profile component 9 and the high-profile component 10 are mounted on different mounting surfaces of the first substrate 7. In the example shown in Figure 4, the high-profile component 10 is mounted on the first surface 71, which is one of the main surfaces of the first substrate 7, and the low-profile component 9 is mounted on the second surface 72, which is the other surface.

[0024] Note that the low-profile component 9 and high-profile component 10 are merely examples, and other electronic components of the same height or with the same heat generation properties may also be used.

[0025] The current sensor 11 is mounted on the second substrate 8 and detects the current flowing through the busbar 4. As shown in Figure 4, the current sensor 11 comprises a core portion 11a and a circuit portion 11b. The core portion 11a comprises a core, a Hall element, and a coil, and is arranged to surround the cylindrical busbar 4.

[0026] The busbar 4 on which the core portion 11a is placed penetrates through a through-hole in the second substrate 8 and is mounted on the first substrate 7. In other words, the core portion 11a is mounted on the second substrate 8 at the location of the through-hole in the second substrate 8.

[0027] The circuit section 11b is a circuit equipped with an operational amplifier and a current conversion circuit, and is connected to the core section 11a, while being mounted on the second substrate 8 at a position away from the core section 11a. In other words, the circuit section 11b can be mounted at any position on the second substrate 8 without being restricted by the position of the core section 11a.

[0028] As a result, the mounting board for the circuit section 11b is not required, and connecting materials such as cables and connectors for connecting the circuit section 11b to the second board 8 are also not required, thus enabling miniaturization while reducing the cost of the electronic device 1.

[0029] Furthermore, by making the busbar 4 cylindrical, the cross-sectional area of ​​the current path can be increased, and since it does not require a large width like a plate-shaped busbar, for example, it becomes possible to miniaturize the electronic device 1.

[0030] In this disclosure, the grommet 5 has a covering portion 51 and a contact portion 52, thereby providing waterproofing to the electronic device 1 while also improving ease of assembly. Here, the shape of the grommet 5 will be specifically explained with reference to Figure 5.

[0031] Figure 5 is a cross-sectional view of the grommet 5. As shown in Figure 5, the grommet 5 comprises a covering portion 51 and a contact portion 52.

[0032] The covering portion 51 tightly covers the area around the tip of the hole in the housing 2 (lid portion 3), while creating a gap 510 at the tip of the hole. This allows the tolerances of the lid portion 3 and the grommet 5 to be absorbed by the gap 510, thereby improving the ease of installation (assembly) of the grommet 5 and preventing moisture from entering the inside of the housing 2 from between the covering portion 51 and the lid portion 3. In particular, when inserting multiple busbars 4 into the grommet 5 simultaneously, even if the tolerances of each busbar 4 vary, the gap 510 of each grommet 5 absorbs the variation, thereby improving the ease of installation of multiple busbars 4.

[0033] Furthermore, the covering portion 51 is U-shaped in the cross-sectional view shown in Figure 5, and the tip 51a on the external side (positive Y-axis side) of the housing 2 (lid portion 3) is a protruding portion that extends toward the housing 2 (lid portion 3).

[0034] Furthermore, the covering portion 51 has a flat surface at its tip 51b on the inner side (negative Y-axis side) of the housing 2 (lid portion 3), which conforms to the housing 2 (lid portion 3), and this flat surface allows it to adhere tightly to the inner side of the lid portion 3.

[0035] In other words, the covering portion 51 is attached to the lid portion 3 by the protruding portion of tip 51a and the flat surface of tip 51b being in close contact with the lid portion 3. This allows a gap to be formed near tip 51a, or in other words, the contact area between the covering portion 51 and the lid portion 3 can be reduced, making it easy to attach and detach the grommet 5.

[0036] The contact portion 52 is connected to the covering portion 51 and positioned in contact with the busbar 4, with its tip 52a tapering to follow the outer surface of the busbar 4. This reduces the contact area between the tip 52a and the busbar 4, thereby improving the ease of insertion of the busbar 4 while preventing moisture from entering the interior of the housing 2 from between the tip 52a and the busbar 4.

[0037] In other words, the grommet 5, with its covering portion 51 and contact portion 52, allows for easy assembly while providing waterproofing to the electronic device 1.

[0038] Furthermore, the contact portion 52 is shaped to be flexible relative to the covering portion 51. Specifically, the grommet 5, formed by the covering portion 51, the contact portion 52, and the connecting portion 500, has a curved shape in cross-sectional view as shown in Figure 5.

[0039] As a result, when the busbar 4 is inserted, the curved shape formed by the connecting portion 500 and the contact portion 52 of the covering portion 51 flexes (the contact portion 52 flexes in the direction of the covering portion 51), thereby improving the ease of inserting the busbar 4.

[0040] Furthermore, the bending of the curved shape allows tolerances to be absorbed even if tolerances occur in the grommet 5 or busbar 4. In other words, the ease of inserting the busbar 4 into the grommet 5 can be improved.

[0041] Furthermore, as shown in Figure 5, the connecting portion 500 is located at the end of the covering portion 51 on the inside side of the housing 2 (the tip 51b side, the negative Y-axis side in Figure 5). The contact portion 52 has a curved shape that extends from the end where the connecting portion 500 is located toward the outside side of the housing 2 (the positive Y-axis side in Figure 5).

[0042] As a result, any moisture adhering to the tip 52a of the contact portion 52 flows into the recess on the connecting portion 500 side, making it less likely for moisture to accumulate between the tip 52a and the bus bar 4, thereby improving waterproofing.

[0043] As described above, the electronic device 1 according to this embodiment comprises a housing 2 (including a lid 3), a first member (bus bar 4), and a second member (grommet 5). The first member protrudes from a hole in the housing 2. The second member is fitted into the hole in the housing 2 and has an insertion opening into which the first member is inserted. The second member has a covering portion 51 that tightly covers the area around the tip of the hole, with a gap formed at the tip, and a contact portion 52 that is connected to the covering portion 51 and positioned in contact with the first member, with its tip 52a having a tapered shape that narrows along the outer surface of the first member. This allows for easy assembly while maintaining waterproofness.

[0044] Further effects and modifications can be readily derived by those skilled in the art. Therefore, broader aspects of the present invention are not limited to the specific details and representative embodiments expressed and described above. Accordingly, various modifications are possible without departing from the spirit or scope of the overall concept of the invention as defined by the appended claims and their equivalents. [Explanation of symbols]

[0045] 1 Electronic equipment 2 cabinets 3 Lid 4 bus bars 5 Grommets 6 heat sinks 7. First substrate 8. Second substrate 9 Low profile parts 10 High-profile parts 11 Current Sensor 11a Core 11b Circuit section 21 External surface 50 Insertion slot 51 Covering part 52 Contact part 71 Page 1 72 2nd page 500 Connection section C Vehicle

Claims

1. The casing and A first member protruding from the hole in the housing, A second member is fitted into the hole of the housing and has an insertion opening into which the first member is inserted, Equipped with, The second member is, A covering portion that tightly covers the area around the tip of the hole, with a gap formed at the tip of the hole, It is connected to the covering portion and positioned in contact with the first member, and has a contact portion whose tip is tapered to follow the outer surface of the first member, The aforementioned covering portion is In cross-sectional view, it is U-shaped, and the tip on the external side of the housing is a protruding portion that extends toward the housing. electronic equipment.

2. Housing and A first member protruding from the hole in the housing, A second member is fitted into the hole of the housing and has an insertion opening into which the first member is inserted, Equipped with, The second member is, A covering portion that tightly covers the area around the tip of the hole, with a gap formed at the tip of the hole, It is connected to the covering portion and positioned in contact with the first member, and has a contact portion whose tip is tapered to follow the outer surface of the first member, The first member is, It is a bus bar, The second member is, It is a grommet. electronic equipment.

3. The aforementioned contact portion is, The covering portion has a shape that allows it to bend. The electronic device according to claim 1 or 2.

4. The second member is, The covering portion, the contact portion, and the connecting portion between the covering portion and the contact portion are curved in cross-sectional view. The electronic device according to claim 3.

5. The aforementioned connecting portion is Of the covering portion, the end portion located on the inside side of the housing is The aforementioned contact portion is, The curved shape extends from the aforementioned end toward the outside of the housing. The electronic device according to claim 4.

6. A first circuit board is placed inside the housing and on which the busbar is mounted, A second substrate is positioned closer to the hole than the first substrate and has a through hole through which the busbar passes, A current sensor having a core portion that covers the periphery of the busbar at a position closer to the hole than the second substrate, and a circuit portion connected to the core portion and mounted on the second substrate. The electronic device according to claim 2, comprising:

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