JP2015053758A - Power conversion device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power conversion device that allows surely transmitting a ground signal to a metal housing having a ground potential.SOLUTION: A power conversion device includes a switching circuit, a control circuit board, an external connection connector, and a metal case. Noise countermeasure circuit components 202 are mounted on a flexible printed circuit board 201 connecting the external connection connector and the control circuit board. A metal base 204 connecting ground wiring of the flexible printed circuit board 201 and the case is fixed to an inner-side connector component 200a so as to be held by the flexible printed circuit board 201 and a housing portion 231. The metal base 204 has a plate portion 204a having pins 204c penetrating through the flexible printed circuit board 201 and connected to the ground wiring, and a connection portion 204b extending from the plate portion 204a and connected to the case.

Description

  The present invention relates to a power converter for a vehicle having an electric motor as a part or all of a drive source such as a hybrid vehicle.

  An electric vehicle and a hybrid vehicle are equipped with a high voltage storage battery used in an inverter device for driving a motor used for traveling and the like, and a low voltage storage battery used for a vehicle control unit, accessories, lights and the like. Such a vehicle is equipped with a DCDC converter device that performs power conversion between a high voltage storage battery and a low voltage storage battery.

  In automobiles, it is important to increase the product competitiveness by increasing the volume of the passenger compartment or luggage compartment as much as possible to improve the comfort and convenience. Therefore, it is necessary to make the inverter device and the DCDC converter device as small as possible so that they can be mounted in a small space.

  Inverter devices and DCDC converter devices mounted on vehicles perform high-voltage high-speed switching, and switching noise is generated. The noise not only prevents the normal operation of the inverter device and DCDC converter device, but also propagates to the internal connection harness between the circuit board mounted inside and the external output connector for external connection signal input / output, There is a possibility that it is output from the external input / output connector to the outside and adversely affects other electronic devices mounted on the vehicle. Also, noise generated from other devices may enter from the external input / output connector and adversely affect the control of the circuit board through the internal connection harness. Therefore, in these apparatuses, countermeasures for both noise generated inside the apparatus and noise entering from the outside of the apparatus are important.

  For example, in the power conversion device described in Patent Literature 1, in a configuration in which a signal is transmitted and received between a control circuit in the device and an external device using a control wiring, a noise removing component is provided in the device wiring connected to the external connection connector. (For example, a capacitor) is provided to remove noise that has entered the apparatus from the outside.

JP 2011-135705 A

  However, as described above, in the configuration in which the noise removing component is provided in the wiring, it is necessary to reliably connect the ground connection side of the terminal capacitor of the noise countermeasure component to the metal case portion.

  A power conversion device according to a first aspect of the present invention includes a switching circuit for performing power conversion, a control circuit board on which a control circuit for controlling the switching circuit is mounted, a switching circuit and a control circuit board, and a ground potential. A metal casing, an external connection connector fixed to the opening of the metal casing, a printed wiring board on which a circuit component for noise removal is mounted and connecting the external connection connector and the control circuit board, and printed wiring A metal member for connecting the ground wiring of the board and the metal housing, and the external connector includes a plurality of lead terminals connected to the printed wiring board so as to penetrate the printed wiring board, and a plurality of lead terminals A non-conductive connector housing that holds the metal member, and the metal member is externally sandwiched between the printed wiring board and the connector housing. Is fixed to the connector, through the printed circuit board has a flat plate portion having at least one protrusion is connected to the ground line, cast Shin from the flat plate portion, a connecting portion connected to the metal housing, the.

  According to the present invention, a ground signal can be reliably transmitted to a metal casing that is at a ground potential.

FIG. 1 is a perspective view showing an external appearance of the DCDC converter device 100. FIG. 2 is a block diagram showing an internal configuration of the DCDC converter device 100. FIG. 3 is an exploded perspective view showing the inside of the case 206. FIG. 4 is a plan view showing the DCDC converter device 100 with the lid 206b removed from the lower case portion 206a. FIG. 5 is a view showing a cross section taken along the line AA of FIG. FIG. 6 is a perspective view showing the inner connector part 200a in a state where the flexible printed wiring board 201 and the metal base 204 are assembled. FIG. 7 is an exploded perspective view of the configuration shown in FIG. FIG. 8 is a plan view of the metal base 204. 9 is an enlarged view of a portion indicated by reference numeral F in FIG. 5 and a cross-sectional view taken along the line BB in FIG. FIG. 10 is a diagram showing examples of EMC measurement waveforms before and after application of the present invention.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. Below, the power converter device which concerns on this invention is demonstrated for the example of the DCDC converter device mounted in electric vehicles, such as a hybrid vehicle. In addition, this invention is applicable not only to a DCDC converter apparatus but other power converters, such as an inverter apparatus.

  FIG. 1 is a perspective view showing an external appearance of the DCDC converter device 100. A set of a transformer circuit for performing power conversion is accommodated in a case 206 formed of metal such as aluminum die cast. The case 206 includes a lower case portion 206a in which a set of transformer circuits that perform power conversion are housed, and a lid 206b that seals the upper opening of the lower case portion 206a. The case 206 is connected to the chassis ground. The lid 206b is bolted to the lower case portion 206a. On the side wall of the lower case portion 206a, a high voltage input / output connector 301 to which a high voltage line is connected and a low voltage input / output connector 302 to which a constant voltage line is connected are provided. Voltage conversion is performed between the two.

  Further, the external connection connector 200 is attached to the side wall of the lower case portion 206a with a fixing screw 205. The external connection connector 200 is provided with a signal terminal for controlling the input of the power supply for operation, the operation state from the outside, or notifying the operation state to the outside.

  FIG. 2 is a block diagram showing an internal configuration of the DCDC converter device 100. FIG. 3 is an exploded perspective view showing the inside of the case 206. The function of the DCDC converter device 100 is power conversion between the high voltage input / output connector 301 and the low voltage input / output connector 302. The current input from the high voltage input / output connector 301 is switched by the high voltage switching circuit 303, and the voltage is converted by the power conversion main transformer 305. Then, after being switched and rectified by the low voltage switching circuit 304, it is output from the low voltage input / output connector 302.

  Switching timings of the high voltage switching circuit 303 and the low voltage switching circuit 304 are controlled by a control circuit 207a mounted on the control circuit board 207. The control circuit 207a controls power conversion by a communication command input from the external connection connector 200. The control circuit 207 a has a function of transferring various types of internal control information to the external control device connected to the external connection connector 200.

  In order to reduce both noise generated inside the DCDC converter apparatus 100 and noise entering from the outside of the apparatus, it can be said that it is best to implement noise countermeasures at the external input / output connector section. Therefore, in the present embodiment, the printed wiring board 201b on which the noise countermeasure circuit component 202 is mounted is connected to the external connection connector 200, and the printed wiring board 201b is connected to the control circuit board 207 via the internal connection harness 201a. I did it.

  In FIG. 2, functionally, the internal connection harness 201a and the printed wiring board 201b are separately illustrated. However, in the present embodiment, the internal wiring harness 201a is formed by the flexible printed wiring board 201. And the printed wiring board 201b are integrally formed. In the following, in the flexible printed wiring board 201, the connector connection portion is called a printed wiring board 201b and the other wiring portions are called an internal connection harness 201a.

  In the flexible printed wiring board 201, reinforcing materials are often provided at both ends connected to a connector or the like. Also in the flexible printed wiring board 201 of the present embodiment, a portion corresponding to the printed wiring board 201b on which the noise countermeasure circuit component 202 is mounted is an area where a reinforcing material is provided.

  In the following, the case where the flexible printed wiring board 201 is used will be described. However, the present invention can be similarly applied to the case where the printed wiring board 201b and the internal connection harness 201a are used.

  As shown in FIG. 3, the external connector 200 includes an inner connector part 200a provided inside the opening 206c of the lower case part 206a and an outer connector part provided outside the opening 206c of the lower case part 206a. 200b. The inner connector part 200a and the outer connector part 200b are fixed by the fixing screws 205 so that they sandwich the wall part of the lower case part 206a. The inner connector part 200a and the outer connector part 200b are formed of a non-conductive material such as a resin material.

  As the noise countermeasure circuit component 202, a terminal capacitor 202a and a line inductor 202b are provided. The terminal capacitor 202a is connected between the signal wiring formed on the printed wiring board 201b and the ground wiring 208. As will be described in detail later, the ground wiring 208 is connected to a metal base 204 that functions as a ground signal transmission member. A part of the metal base 204 is sandwiched between the external connection connector 200 and the lower case portion 206a.

  As shown in FIG. 3, the circuit board on which the high voltage switching circuit 303 is mounted and the circuit board on which the low voltage switching circuit 304 is mounted are provided below the base board 601 for mounting the circuit board. Then, the control circuit board 207 is fixed on the upper surface of the base plate 601. The base plate 601 also functions as a shielding member provided to protect the control circuit board 207 from internal switching noise 401 generated by the high voltage switching circuit 303 and the low voltage switching circuit 304. The base plate 601 is fixed to the lower case portion 206 a and is electrically connected to the case 206.

  FIG. 4 is a plan view showing the DCDC converter device 100 with the lid 206b removed from the lower case portion 206a. The other end of the flexible printed circuit board 201 (the end connected to the control circuit board 207) is pulled out to the upper surface side of the control circuit board 207 through the notch 207b formed in the control circuit board 207. Connected to the control circuit board 207. FIG. 5 is a view showing a cross section taken along the line AA of FIG. The flexible printed wiring board 201 is deformed into a Z shape and connected to the upper surface of the control circuit board 207.

  The control circuit board 207 on which the control circuit 207a for performing switching control is mounted is disposed near the circuit board on which the high voltage switching circuit 303 is mounted and the circuit board on which the low voltage switching circuit 304 is mounted. Therefore, the internal switching noise 401 easily propagates to the internal connection harness 201a of the flexible printed wiring board 201 that connects the control circuit board 207 and the external connection connector 200.

  Since the internal switching noise 401 that has entered the internal connection harness 201a propagates between the external connection connector 200 and the control circuit board 207, noise countermeasures in the control circuit board 207 are impossible. Further, if countermeasures against the external intrusion noise 402 that enters from the outside of the DCDC converter device 100 via the external connection connector 200 are also taken on the control circuit board 207, the DCDC converter device 100 is received from the internal connection harness 201a or the like. Noise will be radiated into the interior of the device, which may affect various circuits.

  The most suitable site for implementing countermeasures against these noises is immediately before going out to the internal switching noise 401, and external to the external DC noise converter device 100 against the external intrusion noise 402. It is in the immediate vicinity of the connection connector 200. Therefore, in the present embodiment, the noise countermeasure circuit component 202 is mounted on the printed wiring board 201b connected to the external connection connector 200, and the internal switching noise 401 and the external intrusion noise 402 are removed.

  Further, in the present embodiment, by adopting the configuration described below, the ground wiring of the printed wiring board 201b is securely connected to the case 206 (lower case portion 206a) connected to the chassis ground. The structure is as follows.

  FIG. 6 is a perspective view showing the inner connector part 200a in a state where the flexible printed wiring board 201 and the metal base 204 are assembled. FIG. 7 is an exploded perspective view of the configuration shown in FIG. As shown in FIG. 7, the inner connector component 200 a includes a plurality of lead terminals 230 and a housing portion (also referred to as a shell) 231 that is formed of an insulating member and holds the lead terminals 230. At both ends of the housing portion 231, fixing portions 231 a in which screw fixing through holes 231 b are formed are formed. A screw hole 231d and a protrusion 231e are formed on the upper surface 231c of the fixing portion 231a.

  Each lead terminal 230 is bent upward in an L shape on the board connection side. The portion bent upward is inserted into a through hole P1 formed in the flexible printed wiring board 201, whereby the lead terminal 230 and the signal wiring of the flexible printed wiring board 201 are connected. Further, the lead terminal 230 inserted into the through hole P1 is soldered.

  Reinforcing materials are provided in the areas indicated by reference numerals D1 and D2 of the flexible printed wiring board 201. The part of the region D2 is a part connected to the control circuit board 207 (see FIG. 4). On the other hand, the region D1 is a portion fixed to the housing portion 231 so as to sandwich the metal base 204, and a through hole P3 for screw fixing is formed. The through hole P4 is a through hole into which the protrusion 231e formed on the fixed portion 231a of the housing portion 231 is inserted.

  The noise countermeasure circuit component 202 is mounted on the area D1 of the flexible printed wiring board 201. The through hole P1 is connected to the signal wiring of the flexible printed wiring board 201, and the lead terminal 230 is inserted and soldered as described above. The through hole P2 is connected to the ground signal wiring of the flexible printed wiring board 201, and a pin 204c of the metal base 204 described later is inserted therein.

  The metal base 204 includes a plate portion 204a and a connecting portion 204b formed to bend downward from the plate portion 204a. The plate portion 204a is sandwiched between the housing portion 231 of the inner connector part 200a and the flexible printed wiring board 201. The connecting portion 204b is a portion that is sandwiched between the fixing portion 231a of the housing portion 231 and the lower case portion, and has a through hole for screw fixing. A plurality of pins 204c are formed on the plate portion 204a so as to protrude upward.

  FIG. 8 is a plan view of the metal base 204. In FIG. 8, the broken line indicates the flexible printed wiring board 201. Through holes 204d and 204e are formed in the plate portion 204a at positions corresponding to the through holes P3 and P4 of the flexible printed wiring board 201 described above. As shown in FIG. 5, when the metal base 204 and the flexible printed wiring board 201 are fastened together with the housing portion 231 with the fixing screws 220, the region indicated by the symbol E in FIG. 8 is the back surface of the flexible printed wiring board 201. Close contact with. In FIG. 6, a part indicated by reference numeral 501 indicates a part to which the lead terminal 230 is connected, and a part indicated by reference numeral 502 indicates a part to which the pin 204 c of the metal base 204 is connected. Both are soldered. The ground signal on the side of the flexible printed circuit board 201 flows into the metal base 204 through the pin 204c and passes through the wide plate portion 204a and the connecting portion 204b to the lower case portion 206a as shown by the solid line with an arrow in FIG. Flows in.

  At the time of fixing, positioning is performed by inserting the protrusion 231e of the housing portion 231 into the through hole 204e of the metal base 204 and the through hole P4 of the flexible printed wiring board 201.

  FIG. 9 shows an enlarged view of a portion indicated by reference numeral F in FIG. 5 and a cross-sectional view taken along line BB in FIG. As shown in the enlarged view of the F part, the plate part 204a (see FIG. 7) of the metal base 204 is sandwiched between the flexible printed wiring board 201 and the inner connector part 200a (part indicated by a broken line 210).

  Further, as shown in the BB cross-sectional view, the connecting portion 204b of the metal base 204 is disposed between the inner connector component 200a and the side wall of the lower case portion 206a, and the inner connector component 200a and the outer connector component 200b. Are fastened together with fixing screws 205. As a result, the inner connector part 200a and the outer connector part 200b are fixed to the lower case part 206a, and the connection part 204b (see FIG. 7) of the metal base 204 is connected to the inner connector part 200a and the lower case part 206a. (A portion indicated by a broken line 209).

  As shown in FIG. 3, the noise shielding base plate 601 is formed with a housing portion 601a for housing the inner connector part 200a to which the flexible printed wiring board 201 is connected. As shown in FIG. 9, the storage portion 601 a is formed so as to surround the inner connector part 200 a fixed to the inner wall of the lower case portion 206 a so as to surround the inner switching noise 401 (FIG. 2, 3) is prevented from entering the inner connector part 200a.

  FIG. 10 shows the noise reduction effect obtained by the above measures. FIG. 10 shows noise transmitted from the DCDC converter apparatus 100 to an external device via the external connection connector 200. When the pre-measurement EMC waveform example 701 and the post-measurement EMC waveform example 702 are compared, the level of the portion indicated by reference numeral G1 is smaller in the post-measurement EMC waveform example 702. In addition, a plurality of peaks indicated by reference numeral G2 in the pre-measurement EMC waveform example 701 are smaller in the post-measurement EMC waveform example 702. In the pre-measurement EMC waveform example 701, the product standard was not satisfied, but in the post-measurement EMC waveform example 702, it can be confirmed that the standard is satisfied and sufficient noise reduction performance is exhibited.

  As described above, in this embodiment, as shown in FIG. 2, the printed wiring board 201b (flexible printed wiring board 201) that connects the external connector 200 and the control circuit board 207 has a noise countermeasure circuit component. 202 is implemented. The metal base 204 connecting the ground wiring 208 and the lower case portion 206a of the printed wiring board 201b is fixed to the external connection connector 200 so as to be sandwiched between the printed wiring board 201b and the housing portion 231. A plate portion 204a having a pin 204c connected so as to penetrate through 201b; and a connection portion 204b extending from the plate portion 204a and connected to the lower case portion 206a.

  By using the metal base 204 as described above, electrical connection with the case 206 is improved, and a ground signal can be reliably transmitted from the printed wiring board 201b to the case 206 connected to the chassis ground. As a result, a noise reduction effect can be achieved as shown in FIG.

  Further, since the metal base 204 is sandwiched between the printed wiring board 201b and the external connection connector 200, the wide area of the printed wiring board 201b (flexible printed wiring board 201) is strong as shown in FIG. It is fixed to the external connection connector 200 together with the metal base 204 while being in close contact with the high metal base 204. As a result, in the printed wiring board 201b, the mechanical strength of the portion sandwiching the metal base 204 can be improved, and a more reliable connection can be performed as compared with the case where the metal base 204 is not used. In particular, in the case of an in-vehicle power conversion device, since the influence of vibration during traveling is large, it is more effective to increase the mechanical strength.

  Further, when the flexible printed wiring board 201 is used, it is difficult to obtain sufficient mechanical strength for connection with the lead terminal 230 because the thickness is smaller than that of a normal printed wiring board. Therefore, in the case of the flexible printed wiring board 201, the mechanical strength can be remarkably improved.

  When the printed wiring board 201b is used instead of the flexible printed wiring board 201, the ground wiring pattern is exposed on the back surface side of the board, that is, the contact surface with the metal base 204, so that the ground wiring of the printed wiring board 201b The electrical contact state with the metal base 204 becomes better, and the ground signal can be dropped to the case 206 more effectively. Of course, in the flexible printed wiring board 201, as long as the ground wiring pattern can be exposed to the back side at the connection portion, the same effect can be obtained.

  In the above-described embodiment, the metal base 204 and the external connection connector 200 are separated from each other. However, the metal base 204 may be integrally formed when the inner connector part 200a is resin-molded. Thereby, it is possible to reduce the number of parts and the number of assembly steps.

  As described above, the function of the metal base 204 also serves as mechanical reinforcement of the flexible printed wiring board 201, and therefore, a metal that is strong and highly conductive is used.

  The plate portion 204 a is formed with pins 204 c that are protrusions that penetrate the flexible printed wiring board 201 and are soldered to the ground wiring 208. By soldering the pin 204c, it is possible to prevent deterioration of the contact portion and deterioration of the noise reduction effect. Note that the soldering of the pins 204c can be performed simultaneously with the solder connection of the external connection connector 200 and the printed wiring board (including the flexible printed wiring board), and the number of manufacturing steps can be reduced.

  The inner connector part 200a includes a fixing part 231a that is fixed to the lower case part 206a in a state where the connection part 204b is sandwiched between the inner connector part 200a and the lower case part 206a. In this manner, by being sandwiched between the lower case portion 206a, electrical contact with the lower case portion 206a can be ensured. Furthermore, as shown in FIG. 9, the connection part 204b is simultaneously fixed to the lower case part 206a only by fixing the inner connector part 200a to the lower case part 206a with the fixing screw 205.

  As a result, the ground wiring 208 of the noise countermeasure circuit component 202 can be finally brought into contact with the case 206, and both noise resistance and functional durability can be achieved at the same time.

  As shown in FIGS. 3 and 9, the external connection connector 200 (inner connector component 200a) between the board on which the switching circuits 303 and 304 are provided and the control circuit board 207 and the flexible printed wiring board 201 are connected. And a base plate 601 made of metal that is disposed between the switching circuit substrate and electrically connected to the case 206.

  Providing such a base plate 601 can prevent radiation noise generated in the switching circuits 303 and 304 from entering the control circuit board 207, the flexible printed wiring board 201, and the external connection connector 200. In particular, when noise enters the external connection connector 200 on the external device side relative to the noise countermeasure circuit component 202, the noise is transmitted to the external device side without being removed. Such noise intrusion can be prevented.

  In addition, the above description is an example to the last, and this invention is not limited to the said embodiment at all unless the characteristic of this invention is impaired.

  DESCRIPTION OF SYMBOLS 100: DCDC converter apparatus, 200: External connector, 200a: Inner connector component, 200b: Outer connector component, 201: Flexible printed wiring board, 201b: Printed wiring board, 202: Noise countermeasure circuit component, 202a: Terminal capacitor 202b: line inductor, 204: metal base, 204a: plate portion, 204b: connection portion, 204c: pin, 206: case, 206b: lower case portion, 207: control circuit board, 207a: control circuit, 208: ground wiring , 230: lead terminal, 231: housing part, 231a: fixing part, 231e: protrusion, 601: base plate

Claims (5)

A switching circuit for performing power conversion;
A control circuit board on which a control circuit for controlling the switching circuit is mounted;
A metal case in which the switching circuit and the control circuit board are housed and set to a ground potential;
An external connector fixed to the opening of the metal casing;
A circuit board for noise removal is mounted, and a printed wiring board for connecting the external connector and the control circuit board,
A metal member for connecting the ground wiring of the printed wiring board and the metal housing,
The external connection connector is
A plurality of lead terminals connected to the printed wiring board so as to penetrate the printed wiring board;
A non-conductive connector housing holding the plurality of lead terminals;
The metal member is
A flat plate portion that is fixed to the external connection connector so as to be sandwiched between the printed wiring board and the connector housing, and has at least one protrusion that passes through the printed wiring board and is connected to the ground wiring;
A power conversion device having a connection portion extending from the flat plate portion and connected to the metal casing. The power conversion device according to claim 1,
The power conversion device in which the protrusion and the ground wiring are connected by soldering. In the power converter device according to claim 1 or 2,
The said connector housing is a power converter device provided with the fixing | fixed part fixed to this metal housing | casing in the state which pinched | interposed the said connection part between this connector housing and the said metal housing | casing. In the power converter according to any one of claims 1 to 3,
A metal made between the control circuit board and the switching circuit and between the external connection connector to which the printed wiring board is connected and the switching circuit, and is electrically connected to the metal casing. A power converter provided with the shielding member. In the power converter according to any one of claims 1 to 4,
The printed wiring board is a power conversion device configured by a flexible printed wiring board.

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