JP2008011660A - Power converter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power converter capable of forming a sealing structure of a terminal connector inside a terminal box, and easily forming a structure for inhibiting electrical noise from generating. <P>SOLUTION: This power converter 5 includes: a cable 4; a terminal 6 for connecting the cable 4; the terminal box 1 with an opening for accommodating the terminal 6 therein; a cover 2 fixed to the terminal box 1 for covering the opening of the terminal box 1; and a sealing member 3 provided between the terminal box 1 and the cover 2. The outer circumference of the sealing member 3 is located on a first position between the outer circumference and the inner circumference of the side wall of the terminal box 1. The terminal box 1 touches the sealing member 3 inside the first position, while the terminal box 1 touches the cover 2 outside the first position. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a power converter, and more particularly to a terminal connection structure in a power converter for an automobile.

  As a conventional terminal box structure, as disclosed in Japanese Patent Application Laid-Open No. 11-346064 (Patent Document 1), a rubber packing is fitted into a groove portion of the terminal box portion, and the terminal box and the cover are fastened with fastening bolts. There is a structure.

  Further, as another structure of the conventional terminal box, as disclosed in FIG. 5 of Japanese Patent Laid-Open No. 2001-327117 (Patent Document 2), the contact surface between the terminal box and the cover is uniformly flat. There is a sealed structure that sandwiches rubber-based material and fastens with fastening bolts.

Japanese Patent Laid-Open No. 11-346064 JP 2001-327117 A (FIG. 5)

  However, in the structure disclosed in Patent Document 1, since the rubber packing is compressed by the groove of the terminal box and the cover, it is necessary to accurately finish the surface of the terminal box and the cover that the rubber packing contacts. Further, when positioning the rubber packing, it is necessary to tighten the positional dimensional accuracy because it is fixed to the casing at the inner periphery of the rubber packing.

  Further, in the structure disclosed in Patent Document 2, since the rubber-based material is uniformly compressed between the terminal box and the cover without a gap, it is necessary to accurately finish the surfaces of the terminal box and the cover in contact with the rubber-based material. . Furthermore, in order to apply a uniform pressure to the rubber-based material, it is necessary to arrange a large number of fastening bolts at equal intervals along the contact surface between the rubber-based material and the cover.

  In the power converter for automobiles, the power converter and the ground of the automobile are at the same potential, and the power converter and the terminal box are electrically connected. For this reason, when a rubber-based material which is an insulating material is used, the terminal box and the cover are insulated, resulting in an unshielded terminal box structure. As a result, electrical noise generated during operation of the switching element in the power converter may adversely affect other electrical devices.

  In order to solve the above problems, an object of the present invention is to easily enable a sealing structure of a terminal connection portion and to suppress electrical noise generated in a power converter at a low cost.

  In order to achieve the above object, a representative one of the power converters of the present invention includes a cable, a terminal for connecting the cable, a terminal box having an opening for accommodating the terminal therein, and a terminal. A power conversion device that covers an opening of a box and has a cover fixed to the terminal box and a sealing material provided between the terminal box and the cover, and the outer periphery of the sealing material is formed on the side wall of the terminal box. Located at the first position between the outer circumference and the inner circumference, the terminal box is in contact with the sealing material inside the first position, and the terminal box is in contact with the cover outside the first position. It is what you are doing.

  Preferably, the sealing material is made of an elastic material. Further, the cover has a concave portion for accommodating the sealing material, and the outer peripheral portion of the concave portion serves as a positioning portion for arranging the sealing material.

  Preferably, the sealing material has an opening, and the inner periphery of the sealing material is located inside the inner periphery of the side wall of the terminal box. An insulating member is provided in the opening of the sealing material.

  ADVANTAGE OF THE INVENTION According to this invention, the power converter device provided with the shield and the sealing structure can be provided cheaply and easily.

  Embodiments of the present invention will be specifically described below with reference to the drawings.

  FIG. 1 is a perspective view of a hybrid power conversion device 5 mounted in an engine room. Terminals for connecting a U-phase, V-phase, and W-phase three-phase AC cable 9 connected to a motor (not shown) to the power converter 5 are provided inside the AC terminal box 7. Further, a terminal for connecting the DC cable 10 connected to a 12V battery and a 36V battery (not shown) to the power converter 5 is provided inside the DC terminal box 8.

  The AC terminal box 7 and the DC terminal box 8 are covered with a common cover 2. The cover 2 is attached to the power conversion device 5 with screws 13.

  FIG. 2 shows a circuit of the power converter 5 shown in FIG. The power conversion device 5 converts a DC voltage from a 36V battery (not shown) into AC and drives the motor 19.

  The DC voltage from the 36V battery is supplied via the smoothing capacitor 20 to the U-phase upper / lower switching elements (15a, 15b), the V-phase upper / lower switching elements (16a, 16b), and the W-phase upper / lower switching elements (17a, 15b). 17b). These switching elements are ON / OFF controlled by applying a signal output from a drive circuit (not shown) to each gate terminal. By such control, an alternating current is applied to the motor 19 from the upper and lower switching elements, and the motor 19 is driven and controlled.

  In the present embodiment, a MOSFET with a built-in diode is used as the switching element, but an IGBT and a diode can be used instead of the MOSFET.

  The switching elements 18a and 18b, the coil 21, and the capacitor 22 have a function of charging the 36V battery when the voltage value of the 36V battery becomes small. A 12V battery is connected between the source and drain of the switching element 18 b via the coil 21 and the capacitor 22. Conversely, when the voltage value of the 12V battery decreases, it is also possible to charge the 12V battery based on the voltage from the 36V battery.

  FIG. 3 shows a cross section of the terminal portion of the power converter 5 in this embodiment. The cover 2 is attached so as to cover the opening of the terminal box 1. The terminal box 1 has a sealing member 3 made of an elastic material sandwiched between the terminal box 1 and the sealing member 3 to be crushed, and the connecting portion of the terminal 6 has a sealed structure. The cover 2 is in contact with the terminal box 1 at the outer periphery of the sealing material 3. In addition, the terminal box 1 of this figure is corresponded to the AC terminal box 7 and DC terminal box of the power converter device 5 shown in FIG.

  The terminal box 1 is made of aluminum, and the cover 2 is made of a plated steel plate. For this reason, it can be set as the shield structure which prevents the electrical noise etc. which generate | occur | produce at the time of operation | movement of a switching element by the terminal box 1 and the cover 2 contacting. In addition, although the other materials may be used for the terminal box 1 and the cover 2, both are preferably made of a conductive material in order to have a shield structure.

  The cover 2 has a positioning portion 12 for easily attaching the sealing material 3. By adopting such a structure, the sealing material 3 may be arranged so that the outer peripheral portion thereof is aligned with the positioning portion 12 of the cover 2. It can be attached to the cover 2.

  The outer periphery of the sealing material 3 is guided by the positioning portion 12 and is fixed at a first position which is larger than the inner periphery of the side wall forming the opening of the terminal box 1 and smaller than the outer periphery of the side wall of the terminal box 1. For this reason, the side wall upper surface of the terminal box 1 is in contact with the sealing material 3 on the inner peripheral side from the first position, and is in contact with the cover 2 on the outer peripheral side from the first position.

  As a result, since the terminal box 1 is in contact with the sealing material 3 from the inner periphery of the outer wall of the terminal box 1 to the first position, it is possible to realize a sealed structure that ensures sealing. Further, since the terminal box 1 is in contact with the cover 2 from the first position to the outer periphery of the outer wall of the terminal box 1, it is possible to realize a shield structure that reliably prevents adverse effects due to electrical noise.

  Moreover, the elastic force of the sealing material 3 can be changed according to the purpose and application. As a result, it is possible to improve the airtightness and easily secure the airtightness of the terminal connection portion.

  Here, as the sealing material 3, it is preferable to use an elastic material such as a rubber-based material. By using an elastic material, it is possible to easily realize a sealing structure that ensures sealing. In particular, it is desirable to use an elastic material having a hardness of 30 to 40 degrees. In this embodiment, foamed EPDM (ethylene propylene rubber) is used as the sealing material 3. However, the present invention is not limited to this, and for example, a silicon sponge having a hardness of 5 to 20 degrees can be used.

  Moreover, although it is preferable to use an elastic material as the sealing material 3, other materials, such as a metal packing, can also be used according to the objective and application. The sealing material 3 may be a conductive material or a non-conductive material.

  The compression rate of the sealing material 3 is, for example, 75%, and the contact width of the sealing material 3 with the terminal box 1 is set to 2 to 3 cm from the inner periphery of the side wall of the terminal box 1. Of course, these can be appropriately changed according to the purpose and application, and the compression rate of the sealing material 3 may be other than 75%, or the contact width may be other than 2 to 3 cm.

  The cover 2 is fixed to the terminal box 1 with a fixing member such as a screw 13. By securing the contact between the terminal box 1 and the cover 2 using a fixing member such as a screw 13, a reliable shield structure can be obtained, and adverse effects due to electrical noise and the like can be reliably prevented. become.

  The cable 4 is connected to the terminal 6 of the power converter 5 in the terminal box 1. The terminal box 1 is fixed to and electrically connected to the power conversion device 5 except for the opening surface of the terminal box 1. Note that the cable 4 in this figure corresponds to the three-phase AC cable 9 and the DC cable 10 of the power converter 5 shown in FIG.

  FIG. 4 is a plan view of the terminal portion of this embodiment. Here, parts having the same functions as those in FIG.

  The three-phase AC cable 9 is connected to a terminal 6 (not shown) inside the AC terminal box 7. Similarly, the DC cable 10 is connected to a terminal (not shown) in the DC terminal box 8.

  The cover 2 is fixed on the opening surfaces of the AC terminal box 7 and the DC terminal box 8 and on the same plane. The AC terminal box 7 and the DC terminal box 8 are each provided with a foamed EPDM sealing material 3. These are compressed by one cover 2 to form a sealed structure.

  Since the AC terminal box 7, the DC terminal box 8, and the cover 2 are made of a conductive material, the shield structure of the AC terminal box 7 and the DC terminal box 8 can be easily established. Preferably, since the two planes of the airtight holding surface made up of each terminal box and the sealing material 3 (not shown) and the shield surface made up of each terminal box and the cover 2 are on the same plane, the structure is complicated. Sex can be eliminated.

  Furthermore, by dividing into the AC terminal box 7 of the AC cable 9 connected to the motor and the DC terminal box 8 of the DC cable 10 connected to the battery, the AC cable 9 and the DC cable 10 can be connected to different terminal portions. It is possible to reduce the number and time of connection and attachment of each terminal box to the power conversion device 5. Further, by adopting the above structure, the cover 2 can be reduced in the number of fixing points to each terminal box, for example, three screws 13 as in this embodiment. In addition, the area | region shown with the dotted line is the outer peripheral part and inner peripheral part of the outer wall in AC terminal box 7 and DC terminal box 8. FIG.

  FIG. 5 is a diagram showing a cross-sectional configuration of the terminal connection portion, focusing on the terminal box 1, the cover 2, and the sealing material 3 in FIG.

  The cover 2 has a recess larger than the opening of the terminal box 1 on the opening. The sealing material 3 is attached to the concave portion of the cover 2. Since the concave surface of the cover 2 is larger than the opening of the terminal box 1, the cover 2 is sandwiched between the terminal box 1 to form a sealed structure in the terminal box 1. When fixing the sealing material 3 to the cover 2, the side wall of the concave portion of the cover 2 becomes the positioning portion 12 (guide portion). For this reason, the sealing material 3 can be easily fixed to the cover 2.

  With the configuration as shown in this figure, since the sealing material 3 can be fixed to the cover 2 in advance, the assembly process of the terminal portion can be reduced.

  FIG. 6 shows a terminal connecting portion in which the concave portion of the cover 2 in FIG. 4 is made flat and a concave portion is provided in the terminal box 1 instead.

  The outer peripheral part of the recessed part provided in the terminal box 1 becomes the positioning part 12 '(guide part) of the sealing material 3. In this case, the sealing material is first fixed to the terminal box 1 and then the cover is fixed to the terminal box 1.

  With the configuration as shown in this figure, the cover 2 can be made flat, so that it is not necessary to perform complicated molding such as providing a recess in the cover 2, and the cover can be easily molded.

  FIG. 7 shows a structure in which the sealing material 3 is provided only in a portion that becomes a confidentiality holding surface with the inside being hollow. FIG. 7A is a plan view of the sealing material 3, and FIG. 7B is a sectional view showing the terminal box 1, the cover 2, and the sealing material 3. The terminal box 1 and cover 2 in FIG. 7B are the same as those in FIG. The inside of the sealing material 3 is hollow, but the inner peripheral portion of the sealing material 3 is located inside the inner periphery of the side wall of the terminal box 1. For this reason, even when the inside of the sealing material 3 is hollow, a reliable shield structure can be obtained by strengthening the contact between the terminal box 1 and the sealing material 3.

  If such a sealing material 3 is employed, the material of the sealing material 3 can be reduced, so that the cost can be reduced.

  FIG. 8 shows a structure in which a stopper 11 which is an insulating member is provided inside the sealing material 3. FIG. 8A is a plan view of the sealing material 3 and the stopper 11, and FIG. 8B is a cross-sectional view showing the terminal box 1, the cover 2, the sealing material 3, and the stopper 11.

  The configuration as shown in this figure is particularly preferably applied to a hybrid power conversion device mounted in an engine room. Specifically, when the sealing material 3 such as foamed EPDM is used in an engine room in an environment of −45 ° C. to 125 ° C., the foamed EPDM may shrink due to a heat cycle. Therefore, as shown in this figure, a stopper 11 made of an insulating member such as polycarbonate having a small thermal shrinkage is sandwiched inside the opening of the terminal box 1 and inside the sealing material 3.

  By adopting such a configuration, it is possible to prevent the sealing material 3 from shrinking due to heat. Moreover, since the stopper 11 which is an insulating member is provided inside the sealing material 3, the insulation between the terminal 6 and the cover 2 can be ensured. That is, with this configuration, it is possible to achieve both a sealed structure of the terminal box 1 and a shield while suppressing shrinkage of the sealing material 3 such as foamed EPDM. The stopper 11 is preferably bonded to the cover 2 together with the sealing material 3.

  As mentioned above, although the Example of this invention was described in detail, this invention is not restricted to this in particular, It can change suitably in the range of the technical idea of this invention.

  According to the embodiment of the present invention, in a power converter, a power converter capable of easily forming a sealed structure of a terminal connection portion in a terminal box and suppressing generated electric noise is provided at low cost. be able to.

It is a whole perspective view of the power converter device in a present Example. It is a circuit diagram of the power converter device in a present Example. It is sectional drawing of the terminal part of the power converter device in Example 1. FIG. It is a top view of the terminal part of the power converter in Example 1. It is principal part sectional drawing of the terminal part of the power converter device in Example 1. FIG. It is principal part sectional drawing of the terminal part of the power converter device in Example 2. FIG. (A) It is a top view of the sealing material in Example 3. FIG. (B) It is sectional drawing of the terminal part of the power converter device in Example 3. FIG. (A) It is a top view of the sealing material in Example 4, and a stopper. (B) It is sectional drawing of the terminal part of the power converter device in Example 4. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Terminal box, 2 ... Cover, 3 ... Sealing material, 4 ... Cable, 5 ... Power converter, 6 ... Terminal, 7 ... AC terminal box, 8 ... DC terminal box, 9 ... Three-phase AC cable, 10 ... DC Cable, 11 ... stopper, 12, 12 '... positioning part,
13 ... Screw.

Claims (10)

Cable and
A terminal for connecting the cable;
A terminal box having an opening for accommodating the terminal therein;
A cover that covers the opening of the terminal box and is fixed to the terminal box;
A power conversion device having a sealing material provided between the terminal box and the cover,
The outer periphery of the sealing material is located at a first position between the outer periphery and the inner periphery of the side wall of the terminal box,
Inside the first position, the terminal box is in contact with the sealing material,
The power converter according to claim 1, wherein the terminal box is in contact with the cover outside the first position. The power conversion device according to claim 1,
The terminal box and the cover are made of a conductive material, and are fixed using a fixing member. The power conversion device according to claim 1 or 2,
The power conversion device, wherein the sealing material is made of an elastic material. The power conversion device according to claim 3,
The power conversion device, wherein the sealing material is made of foamed EPDM. In the power converter according to any one of claims 1 to 4,
The cover has a recess for storing the sealing material;
The power converter according to claim 1, wherein an outer peripheral portion of the concave portion serves as a positioning portion for arranging the sealing material. The power conversion device according to claim 5, wherein
The contact surface of the terminal box and the sealing material is on the same plane as the contact surface of the terminal box and the cover. In the power converter according to any one of claims 1 to 4,
The terminal box has a recess for storing the sealing material. The power conversion device according to claim 7, wherein
The contact surface of the cover and the sealing material is on the same plane as the contact surface of the cover and the terminal box. In the power converter device according to any one of claims 1 to 8,
The sealing material has an opening,
The power converter according to claim 1, wherein an inner periphery of the sealing material is located inside an inner periphery of the side wall of the terminal box. The power conversion device according to claim 9, wherein
An insulating member is provided in the opening of the seal material.

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