JP5071733B2 - Protective cover - Google Patents

Description

  The present invention relates to a protective cover for closing an opening of a die cast case in which an electronic unit such as an inverter is accommodated.

  For example, an inverter case that accommodates an inverter is provided with an opening for connecting to an external electric device. The cable of the electric device is inserted from one opening, and the terminals are fastened by screwing or the like from another opening. That is, the inverter case is provided with an opening for inserting a cable and an opening for fastening work. As an inverter apparatus, it describes in Unexamined-Japanese-Patent No. 2007-89259 (patent document 1), for example. The inverter case is mainly made of aluminum die cast.

A resin protective cover is attached to the opening so that foreign matter such as dust does not enter the case when the inverter device is transported. The inverter device is transported with a protective cover attached. The protective cover is particularly fitted to the opening for fastening work so that dust attached to the protective cover does not enter even if the protective cover is once removed and reattached. That is, the externally fitted protective cover is configured to be fitted from the outside to the peripheral wall formed around the opening.
JP 2007-89259 A

  The outer cover protective cover has a fitting portion provided for fitting with the peripheral wall. The fitting part has a structure in which a force is applied to the peripheral wall from the outside to the inside. Therefore, a force is applied to the protective cover from the peripheral wall as a reaction force.

  Here, as shown in FIG. 8, since the die-cast case has an operation of removing from the mold, drafts are formed in each part. Accordingly, a draft angle is also formed on the peripheral wall. The wall thickness of the peripheral wall gradually decreases from the inside of the case to the outside due to the draft angle. The force applied to the protective cover from the peripheral wall is divided into the outer peripheral side and the direction in which the protective cover is removed. As a result, the protective cover is warped and easily detached from the case.

  This invention is made | formed in view of such a situation, and it aims at providing the protective cover which can prevent the removal | separation from a die-cast case.

  The protective cover of the present invention is a protective cover used for closing an opening in a die-cast case that houses an electronic unit that performs power conversion between a battery and an electric device, and has a contour shape corresponding to the opening. And a protective cover that is externally fitted to the peripheral wall portion that forms the opening. At least one fitting convex portion protruding to the side is provided, and the flat portion is characterized in that a cut along the convex shape is formed in the vicinity of each fitting convex portion.

  According to this, the reaction force received by the protective cover can be released due to the widening of the cut at the time of mounting. That is, the component force received from the warp of the protective cover or the opening peripheral wall is suppressed. Therefore, the component force in the direction in which the protective cover is removed is also suppressed. According to the protective cover of the present invention, detachment from the die-cast case is prevented.

  Here, it is preferable that the cut is formed so as to be located outside the inner peripheral edge of the projecting end surface of the opening peripheral wall portion in a state where it is mounted on the opening peripheral wall portion of the die cast case. As a result, even if dust enters from a widened cut, the dust is prevented from entering by the opening peripheral wall and cannot directly enter the opening. That is, it is possible to prevent the disconnection and maintain the protection accuracy.

  Here, it is preferable that the fitting convex portion is formed in a convex curve shape that is convex in the radial direction, and the notch has a convex curve shape that is concentric with the convex curve shape of the fitting convex portion. By making the fitting convex part into a convex curve shape, an appropriate elastic force can be applied to the opening peripheral wall part during fitting. In this case, since the notch has the convex curve shape, the notch spreads according to the deformation of the fitting convex portion, and the component force is more reliably suppressed. The convex curve shape means a convex curve as a whole and may partially include a straight line.

  Here, it is preferable that the cut is further cut so that both end portions thereof face the inside of the diameter. That is, it is preferable that the blade has escaped inward at both ends thereof. Thereby, the damage of the plane part by cutting is suppressed.

  According to the protective cover of the present invention, detachment from the die-cast case is prevented.

  Next, the present invention will be described in more detail with reference to embodiments. In the present embodiment, a protective cover used for a PCU (power control unit) mounted on a vehicle is taken as an example. The protective cover 1 of this embodiment is demonstrated with reference to FIGS. FIG. 1 is a perspective view of a PCU. FIG. 2 is a perspective view of the PCU to which the protective cover 1 is attached. FIG. 3 is a view of the opening peripheral wall portion 91 (92) as viewed from above. FIG. 4 is a perspective view of the protective cover 1. FIG. 5 is a plan view of the protective cover 1. 6 is a cross-sectional view taken along line AA in FIG. FIG. 7 is a schematic cross-sectional view showing a state where the protective cover 1 is attached. However, in FIG. 1 and FIG. 3, the inside of the die cast case is omitted.

  First, the PCU will be described. As shown in FIGS. 1 and 2, the PCU includes an electronic unit (not shown) and a die cast case 9. The electronic unit includes a battery connection terminal connected to a battery terminal and an MG connection terminal connected to a terminal of an MG (motor generator) (corresponding to the “electric device” in the present invention). In the present embodiment, the electronic unit is connected to two MGs. Therefore, the electronic unit includes two MG connection terminals. The electronic unit performs step-up / step-down and power conversion (inverter) between the battery and the MG.

  The die cast case 9 is made of aluminum die cast and accommodates the electronic unit inside. The die-cast case 9 is mainly formed with four opening peripheral wall portions 91 to 94 and a battery connection portion 95.

  Each of the opening peripheral wall portions 91 to 94 protrudes in an annular shape from the surface of the die-cast case 9 and forms openings 91a to 94a on the inner side of the annular shape. In other words, each opening peripheral wall part 91-94 is formed along the edge of each opening 91a-94a. The openings 91a to 94a have an oval shape in which a short side of the rectangle is curved outward.

  The opening peripheral wall portion 91 protrudes upward from the surface of the die cast case 9 over the entire circumference around the opening 91a. Here, the opening peripheral wall portion 91 has a draft, so that the wall thickness gradually decreases as it goes upward. The draft angle is, for example, about 1 degree to 2 degrees.

  The opening peripheral wall portion 91 has a flat upper end (projecting end surface 91b). The opening peripheral wall portion 92 has the same shape as the opening peripheral wall portion 91. The opening peripheral wall portions 93 and 94 have the same shape as the opening peripheral wall portion 91, although the opening direction and the protruding direction are horizontal. In addition, the protrusion end surface 91b (92b) of the opening surrounding wall part 91 (92) is a hatched part in FIG.

  The opening 93a (94a) is for inserting an MG cable, and is open in the horizontal direction. An MG connection terminal of the electronic unit is disposed behind each of the openings 93a and 94a. The opening 91a (92a) is for fastening the MG connection terminal and the MG cable terminal, and is open in the vertical direction. An operator performs the fastening operation | work which screws an internal terminal through the opening 91a (92a) from upper direction. The battery connection part 95 is a part for connecting the cable terminal of the battery and the battery terminal part of the electronic unit, and is open in the horizontal direction.

  Here, when the PCU is transported, an internal protective cover is attached to the opening peripheral wall portions 93 and 94. An outer-fitting protective cover 1 to be described later is attached to the opening peripheral wall portions 91 and 92. Hereinafter, the protective cover 1 will be described.

  The protective cover 1 is made of a translucent resin (for example, PP: polypropylene) and is integrally molded. The protective cover 1 includes a flat surface portion 2, a side surface portion 3, a flange portion 4, and a knob portion 5. The flat surface portion 2 is a flat plate that can cover the opening 91a (92a), and has a contour shape corresponding to the opening 91a (92a). That is, the flat surface portion 2 has an elliptical shape that is slightly larger than the opening 91a (92a) and has a rectangular short side curved outward. A notch 21 is formed at a predetermined position on the edge of the plane portion 2. The cut 21 will be described later.

  The side surface portion 3 extends from the edge portion of the flat surface portion 2 in the substantially vertical direction of the flat surface portion 2. The side surface portion 3 extends over the entire circumference of the flat surface portion 2. The side surface portion 3 is slightly lower than the height of the opening peripheral wall portion 91 (92) in the substantially vertical direction of the flat surface portion 2. In a state where the protective cover 1 is attached to the die cast case 9 (attached state), the side surface portion 3 is located on the outer peripheral side of the opening peripheral wall portion 91 (92). After mounting, the flat surface portion 2 is in contact with the protruding end surface 91b (92b) of the opening peripheral wall portion 91 (92).

  The side surface portion 3 is provided with four fitting convex portions 31 to 34 protruding toward the inner peripheral side. The fitting convex portions 31 to 34 are formed by curving a part of the side surface portion 3 in a convex curve shape toward the inner peripheral side. In addition, the protruding end portion having a convex curve shape is a straight line shape substantially parallel to the long side of the opening peripheral wall portion 91 (92). The fitting convex portions 31 to 34 and the opening peripheral wall portion 91 (92) are in surface contact in the mounted state.

  The fitting convex part 31 and the fitting convex part 32 are formed in the position which mutually opposes. The fitting convex part 33 is located next to the fitting convex part 31 with a space. The fitting convex portion 34 is formed at a position facing the fitting convex portion 33.

  The fitting convex portions 31 to 34 abut on the outer surface of the opening peripheral wall portion 91 (92) having a draft angle in the mounted state. And the fitting convex parts 31-34 give an elastic force from the outer side with respect to the opening surrounding wall part 91 (92). Thereby, the protective cover 1 is fitted to the opening peripheral wall portion 91 (92).

  The flange portion 4 extends in parallel to the plane portion 2 from the lower end portion of the side surface portion 3. The knob portion 5 has a bellows shape and is formed on the flange portion 4. The knob portion 5 is formed on one short side of the flat plate portion 2. The knob portion 5 is a portion that is mainly pinched when an operator removes the protective cover 1.

  Here, the notch 21 of the plane part 2 will be described. As for the plane part 2, the part in which the fitting convex parts 31-34 are formed is curving according to the said convex shape. That is, the flat part 2 has four concavely curved parts. The notch 21 is an edge of the flat portion 2 and is formed in the vicinity of the concavely curved portion (hereinafter referred to as the concave portion 2a). That is, the notch 21 is formed in the vicinity of the fitting convex portions 31 to 34.

  The cut 21 is formed along the curvature of the recess 2a. In other words, the cuts 21 are formed along the convex shapes of the convex portions 41 to 44. Specifically, the notch 21 has a convex curve shape that is concentric with the convex curve shape of the fitting convex portions 31 to 34. And the part of the cut | notch 21 corresponding to the protrusion end part of the fitting convex parts 31-34 is linear form according to the shape of the said protrusion end part.

  The cuts 21 are formed with a length equal to or greater than the width of the concave portion 2a (fitting convex portion) in the extending direction of the long side of the plane portion 2 (the width in the left-right direction in FIG. 5). Further, the notch 21 extends to the outside from the position along the recess 2a, and both ends are curved toward the center of the plane portion 2. In other words, the cut 21 is cut so that both end portions thereof face the inside of the diameter. That is, the notch 21 of this embodiment has a width larger than that of the recess 2a, and the blades are released at both ends. As a result, the reaction force is reliably suppressed, and the flat portion 2 is prevented from being damaged by the cutting.

  Further, the cut 21 is formed so as to be located on the outer side (outer peripheral side) than the inner peripheral edge of the protruding end surface 91b (92b) of the opening peripheral wall portion 91 (92). In other words, the notch 21 is formed on the plane portion 2 from a position corresponding to the inner peripheral edge of the protruding end surface 91b (92b) to the end of the edge portion of the plane portion 2. Specifically, the distance from the end of the edge of the plane portion 2 to the notch 21 is about 1 mm excluding both ends.

  According to the protective cover 1 of the present embodiment, as shown in FIG. 7, the reaction force received by the protective cover 1 can be released by expanding the notch 21 during fitting. That is, the component force received from the warp of the protective cover 1 or the opening peripheral wall portion 91 (92) is suppressed. Therefore, the component force in the direction (upward) in which the protective cover 1 is removed is also suppressed. Thereby, it is prevented that the protective cover 1 comes off from the die-cast case 9.

  Further, even if dust enters from the widened cut 21, the dust is prevented from entering by the opening peripheral wall portion 91 (92). In an electric device that handles a high voltage such as a vehicle inverter or a PCU, if a foreign object enters the case, it may cause electric leakage or the like. However, according to the protective cover 1 of the present embodiment, detachment is prevented and the protection accuracy can be maintained. The shape of the protective cover 1 such as the fitting convex portion is not limited to the above.

It is a perspective view of PCU. It is a perspective view of PCU to which the protective cover 1 was attached. It is the figure which looked at the opening surrounding wall part 91 (92) from upper direction. 1 is a perspective view of a protective cover 1. FIG. 2 is a plan view of the protective cover 1. FIG. It is the sectional view on the AA line of FIG. It is a schematic cross section which shows the state which attached the protective cover 1. FIG. It is a schematic cross section which shows the conventional protective cover and a surrounding wall.

Explanation of symbols

1: Protective cover,
2: plane part, 21: notch,
3: side part, 31-34: fitting convex part,
9: Die-cast case,
91-94: Opening peripheral wall part,
91a-94a: Opening, 91b, 92b: Protruding end surface

Claims (4)

A protective cover used to close an opening in a die-cast case that houses an electronic unit that performs electric power conversion between a battery and an electrical device, the planar part having a contour shape corresponding to the opening, and the planar part A protective cover that is fitted to the peripheral wall portion that forms the opening, and a side surface portion that extends from the edge portion in a substantially vertical direction over the entire circumference.
The side part is provided with at least one fitting convex part projecting to the inner peripheral side,
The flat cover is formed with a cut along the convex shape in the vicinity of each of the fitting convex portions.   2. The protective cover according to claim 1, wherein the notch is formed to be positioned outside an inner peripheral edge of a protruding end surface of the opening peripheral wall in a state where the opening is attached to the opening peripheral wall of the die cast case. . The fitting convex portion is formed in a convex curve shape that is convex in the radial direction,
The protective cover according to claim 1 or 2, wherein the cut has a convex curve shape concentric with the convex curve shape of the fitting convex portion.   The protective cover according to claim 3, wherein the cut is cut so that both end portions thereof face the inside of the diameter.

Images