JP6332450B2 - Power unit - Google Patents

Description

The present invention relates to a power unit .

  This application claims priority based on Japanese Patent Application No. 2014-142081 filed on Jul. 10, 2014. For the designated countries that are allowed to be incorporated by reference, The contents described in the application are incorporated into the present application by reference and made a part of the description of the present application.

  2. Description of the Related Art Conventionally, there is known a power conversion device in which a plurality of electronic components constituting a power conversion circuit and a cooler that cools the electronic components are accommodated in a case. And in the said power converter device, an electronic component and a cooler are fixed to a flame | frame, and are integrated with the flame | frame and comprise one internal unit. The internal unit is fixed to the case and sealed in the case. The frame has a unit fixing part and a capacitor fixing part for fixing the capacitor. The capacitor fixing part is disposed inside the unit fixing part. This suppresses vibrations transmitted from the capacitor to the case while enhancing the synthesis of the case (Patent Document 1).

JP 2011-182631 A

  Incidentally, there are the following two factors that cause the power converter to vibrate. The first factor is that the components (capacitors in Patent Document 1) constituting the power conversion device are sources of vibration. A 2nd factor is that a power converter device vibrates because the vibration which generate | occur | produces in structures other than a power converter device is transmitted to a power converter device.

  However, in the technique of the above-mentioned Patent Document 1, although effective against the vibration generated by the first factor, the vibration suppressing effect cannot be sufficiently obtained for the vibration generated by the second factor. There was a problem.

The problem to be solved by the present invention is to provide a power unit for an electronic component that can suppress not only the vibration caused by the first factor but also the vibration caused by the second factor.

  In the present invention, an electronic component is accommodated by a housing having a first member and a second member, and the first member and the second member are fastened by a fastening member. The first member has a fastening portion fastened by a fastening member on the surface of the first member. And the said subject is solved by comprising a rib so that the direction which goes to a fastening site | part from the predetermined position on the surface of a 1st member may be followed.

According to the present invention, the vibration eigenvalue of the power converter can be shifted from the vibration eigenvalue of other components while increasing the rigidity of the surface of the first member, so that the vibration of the power unit can be suppressed.

It is a figure which shows the power unit which concerns on embodiment of this invention, (a) is a top view of a power unit, (b) shows the side view of a power unit. FIG. 2A is a plan view of the housing, and FIG. 2B is a side view of the housing. 3A is a plan view of the upper housing, and FIG. 3B is a cross-sectional view taken along line III-III in FIG. 4A is a plan view of the housing, and FIG. 4B is a side view of the housing. FIG. 5A is a plan view of the housing, and FIG. 5B is a side view of the housing. 6A is a plan view of the upper housing, and FIG. 6B is a cross-sectional view taken along the line VI-VI in FIG. 6A. FIG. 7A is a plan view of the upper housing, and FIG. 7B is a cross-sectional view taken along the line VII-VII in FIG. 8A is a plan view of the upper housing, FIG. 8B is a cross-sectional view taken along the line VIIIa-VIIIa in FIG. 8A, and FIG. 8C is a cross-sectional view of FIG. It is sectional drawing which follows the VIIIb-VIIIb line.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
<< First Embodiment >>
FIG. 1 is a diagram showing a power unit in which a power conversion device and a power device according to an embodiment of the present invention are integrated. The power unit is used as a drive source for an electric vehicle or a hybrid vehicle, and is provided in the vehicle. The power unit includes a power device 10, a power converter 20, a transmission 30, a vibration isolation support device 40, a spring 50, a bolt 60, and a rib 71.

  The power unit 10 is a motor that is driven by electric power supplied from a battery (not shown). Power device 10 is a drive source of a vehicle that is connected to a drive shaft of the vehicle and is driven by AC power from power conversion device 20. When the power unit 10 is driven, the power unit 10 becomes a generation source (vibration source) that generates vibration. The excitation force due to vibration is represented by a value obtained by multiplying the number of rotations of the motor by an integer. The rotation speed of the motor is represented by the relationship between the number of poles of the rotor and the stator and the drive frequency.

  The power conversion device 20 includes an electronic component 21, a substrate 22, and a housing 23. The power conversion device 20 converts the power supplied from the battery, and outputs the converted power to the power unit 10. The power conversion device 20 is a structure that houses the electronic component 21. The electronic component 21 is a circuit element that constitutes an inverter and a rectifier. Taking an inverter as an example, the electronic component 21 corresponds to a switching element such as an IGBT and a diode.

  The substrate 22 is a plate-like circuit board. The substrate 22 is supported by the housing 23. The housing 23 accommodates the electronic component 21 and the substrate 22. The housing | casing 23 is comprised with metals, such as aluminum. In addition, the housing | casing 23 may be comprised with members, such as not only a metal but resin. The casing 23 is fastened to the power unit 10 by bolts. That is, the power converter 10 and the power converter 20 are integrated by fixing the power converter 20 to the power apparatus 10. Therefore, when the power device 10 vibrates, the vibration propagates to the power conversion device 20. Further, when the power conversion device 20 vibrates by driving the inverter, the vibration propagates to the power device 10.

  The housing 23 has an upper housing 23a and a lower housing 23b. The structure of the housing | casing 23 is demonstrated using FIG. FIG. 2A shows a plan view of the housing 23, and FIG. 2B shows a side view of the housing 23. Note that the power unit according to the present embodiment is configured to provide the ribs 71 on the housing 23, but the ribs are not shown in FIG. The specific configuration of the rib 71 will be described later.

  The upper housing 23a is a plate-like metal member, and is formed to be a lid of the lower housing 23b. The lower housing 23 b is a main body portion of the housing 23. The lower housing 23b opens a surface covered by the upper housing 23a, and the surface other than the opened surface is a wall surface. With the opening of the lower housing 23b closed by the upper housing 23a, the electronic component 21 is accommodated in a space formed by the upper housing 23a and the lower housing 23b. The mass of the upper housing 23a is smaller than the mass of the lower housing 23b, and the rigidity of the upper housing 23a is lower than the rigidity of the lower housing 23b. Therefore, the upper housing 23a has a structure that is easier to vibrate than the lower housing 23b.

  The upper housing 23 a and the lower housing 23 b are fastened by bolts 60. As shown in FIG. 2A, the surface of the upper housing 23 is rectangular. Then, on the surface of the upper housing 23a, the four corner portions are portions to be fastened by the bolts 60 (hereinafter also referred to as fastening portions). In addition, on the surface of the upper housing 23a, in addition to the fastening portions at the four corners, a portion located between the four corners is also a fastening portion along the long side. That is, the fastening portion is provided on the outer peripheral portion of the rectangular surface. And the outer peripheral part of the surface of the upper housing | casing 23a and the side wall of the lower housing | casing 23b are fastened with the volt | bolt 60. FIG.

  As shown in FIG. 1, the transmission 30 converts the rotational speed and torque between the power unit 10 and the drive shaft. The transmission 30 is fastened to the power unit 10 by bolts or the like. The anti-vibration support device 40 supports the power device 10, the power conversion device 20, and the transmission 30 on the vehicle body. The anti-vibration support device 40 is a device for preventing the vibrations of the power device 10, the power conversion device 20, and the transmission 30 from propagating to the vehicle body. The anti-vibration support device 40 is made of resin. The anti-vibration support device 40 is fixed to the transmission 30. The anti-vibration support device 40 is fixed to the vehicle body via a spring 50.

  Next, the vibration of the housing 23 will be described. For example, when the electronic component 21 vibrates due to the switching operation of the switching element constituting the electronic component 21, the power conversion device 20 serves as a vibration source. Since the housing 23 is shaped to cover the electronic component 21, the housing 23 is likely to vibrate compared to other components of the power conversion device 20. For example, when the power device 10 becomes a vibration source and vibration is generated, the vibration propagates to the power conversion device 20. Since the power unit 10 is fastened to the housing 23, the housing 23 vibrates. Further, when the vibration frequency of the casing 23 is close to the natural value (natural vibration frequency) of the transmission 3, the noise of the power unit increases due to resonance.

  FIG. 3 is a diagram for explaining the vibration of the upper housing 23a. 3A is a plan view of the upper housing 23a, and FIG. 3B is a cross-sectional view taken along the line III-III in FIG. 3A. The dotted line in FIG. 3B represents the vibration mode of the upper housing 23a.

  The outer peripheral portion of the surface of the upper housing 23 a is fastened by a bolt 60. Therefore, the rigidity of the outer peripheral portion is high. On the other hand, the rigidity of the central portion of the surface is low. Therefore, when vibration is transmitted to the housing 23, the upper housing 23a vibrates as indicated by a dotted line in FIG. The amount of deformation of the upper casing 23a due to vibration is greatest at the central portion A of the surface of the upper casing 23a. That is, the central portion A becomes a vibration antinode, and the outer peripheral portion becomes a vibration node. Also, the dotted line in FIG. 3B shows the vibration waveform in the primary mode, but the casing 23 generates not only the vibration in the primary mode but also the vibration in the secondary mode.

  The vibration in the primary mode can be suppressed, for example, by increasing the mass of the upper casing 23a. On the other hand, the vibration of the secondary mode vibration cannot be sufficiently suppressed only by increasing the mass of the upper casing 23a. The vibration of the secondary mode vibration can be suppressed by shifting the eigenvalue of the upper housing 23a so that the eigenvalue of the power conversion device 20 and the eigenvalue of the peripheral component do not approach each other. Therefore, in the present embodiment, the rib 71 is provided on the upper housing 23a so that not only the vibration in the primary mode but also the vibration in the secondary mode can be suppressed.

  FIG. 4 is a view for explaining the housing 23 and the rib 71. 4A is a plan view of the housing 23 and the rib 71, and FIG. 4B is a side view of the housing 23 and the rib 71. The rib 71 is a member for suppressing the vibration of the upper casing 23a, and is provided on the surface of the upper casing 23a. The rib 71 is made of the same metal as that of the housing 23. The rib 71 is formed in the shape of three straight rails. Further, the midpoints of the three ribs 71a, 71b, 71c are at the same position, and the midpoint is located at the central portion A of the upper housing 23a. The rib 71 a is formed along the direction from the central portion A toward the bolt 60. The bolts 60 are bolts positioned between the bolts 60 positioned at the four corners, and are opposed in the direction along the short side of the upper housing 23a. The short side is the shorter side of the four sides forming the rectangular surface of the upper housing 23a.

  The rib 71 b is formed along the direction from the central portion A toward the bolt 60. The bolts 60 are located at the four corners of the surface of the upper housing 23a and are located on the diagonal lines of the surface of the upper housing 23a. The rib 71c is formed along the direction from the central portion A toward the bolt 60.

  That is, on the surface of the upper housing 23a, the ribs 71a, 71b, 71c are formed along the direction from the central portion A toward each bolt 60. In other words, the ribs 71a, 71b, 71c are formed on a line connecting the pair of bolts 60, and the midpoint of the ribs 71a, 71b, 71c is located on the antinode of the surface of the upper housing 23a. The pair of bolts 60 are opposed to each other with the central portion A as a boundary on the surface of the upper housing 23a.

  As described above, the rib 71 is provided in the upper housing 23a. Thereby, the rigidity of the upper housing 23 a is increased by the rib 71. Furthermore, since the rib 71 is formed along the direction from the position on the surface of the upper housing 23a toward the bolt 60, the eigenvalue of the vibration of the upper housing 23a can be shifted.

  By the way, the following method is mentioned as a method of suppressing the vibration of the power converter device 20. For example, there is a method of arranging a vibration isolating member between the power device 10 and the power conversion device 20. However, the cost is increased by providing the vibration isolation member. As another method, it is conceivable to cover the power conversion device 20 with a soundproof member. However, the cost increases as the soundproofing member is provided.

  As another method, it is conceivable to increase the mass of the vibration surface of the housing 23. The vibration surface corresponds to a surface on which vibration is easily generated among the surfaces constituting the housing 23. However, in order to suppress vibrations simply by increasing the mass, the mass must be significantly increased. It is also conceivable to increase the rigidity of the vibration surface of the housing 23. However, when the devices constituting the power unit are densely combined as in the present embodiment, the eigenvalue of the housing 23 is the value of the surrounding configuration so that the devices do not resonate. The value must be far from the eigenvalue. Therefore, as a result, the mass of the housing 23 increases, and the size of the power unit increases.

  On the other hand, in the present embodiment, the rib 71 is provided in the housing 23, whereby the mass of the housing 23 is increased and the vibration in the primary mode is suppressed. Further, since the rib 71 is formed along the direction from the antinode of the surface of the upper housing 23a toward the bolt 60, the vibration of the secondary mode is suppressed while minimizing an increase in the mass of the housing 23. doing. Although the mass of the housing 23 is increased by providing the rib 71 on the housing 23, if the deviation of the eigenvalue of the housing 23 is large with respect to the increase in the mass due to the rib 71, the eigenvalue of the housing 23 is It can be separated from the eigenvalue of the device 10 or the like. Therefore, in the present embodiment, the ribs 71 are not only provided on the housing 23 but also provided on the surface of the upper housing 23a from a low rigidity portion to a high portion. Thereby, resonance with the power unit 10 or the like can be avoided while increasing the rigidity of the surface of the upper housing 23a. As a result, this embodiment can suppress vibration of the power conversion device 20 and suppress noise of the power unit.

  Further, when the power conversion device 20 is mounted on an electric vehicle or the like, vibration of the power conversion device 20 can be suppressed and noise of the power conversion device 20 can be suppressed with a simple configuration, space saving, and low cost. As a result, the quietness in the passenger compartment can be improved.

  In the present embodiment, when the surface of the upper housing 23a vibrates, the fastening portion by the bolt 60 becomes a node of the vibration wave, and the central portion of the surface corresponds to the antinode of the vibration wave. Therefore, the rib 71 is formed from the antinode portion of the vibration wave toward the node portion. As a result, the rigidity of the portion of the surface of the upper housing 23a where the amount of deformation due to vibration is large is increased, and resonance with the power unit 10 or the like can be avoided. As a result, vibration of the power conversion device 20 can be suppressed and noise of the power unit can be suppressed.

  In the present embodiment, the rib 71 is provided outside the surface of the upper housing 23a, but may be provided inside. Of the pair of surfaces of the upper housing 23, the inner surface is a surface facing the electronic component 21.

  In the present embodiment, when the antinode of the vibration wave of the upper housing 23a is not the central portion of the surface of the upper housing 23a, the midpoint of the rib 71 is adjusted to the position of the antinode of the vibration wave. Thus, the rib 71 may be configured so that the midpoint of the rib 71 is located at a position other than the central portion of the surface.

  In the present embodiment, the housing structure for suppressing vibration is not limited to the power conversion device 20 and may be other devices. The fastening member that fastens the upper housing 23a and the lower housing 23b is not limited to the bolt 60, and may be another member.

  The bolt 60 corresponds to the “fastening member” of the present invention, the upper housing 23a corresponds to the “first member” of the present invention, the lower housing 23b corresponds to the “second member” of the present invention, The ribs 71a to 71c correspond to the “first rib” of the present invention.

<< Second Embodiment >>
The power converter device 20 which concerns on other embodiment of this invention is demonstrated using FIG. The present embodiment is different from the first embodiment described above in that the tip portions of the ribs 71 a to 71 c are in contact with the bolt 60. Other configurations are the same as those in the first embodiment described above, and the description thereof is incorporated. FIG. 5A shows a plan view of the housing 23, and FIG. 5B shows a side view of the housing 23.

  The ends of both ends of the rib 71 a are in contact with the bolt 60. The ends of both ends of the ribs 71 b and 71 c are in contact with the bolt 60. Since the outer peripheral portion of the upper housing 23a is fastened by the bolt 60, the rigidity is high. That is, the rib 71 is provided so that the ends of the ribs 71a to 71c are in contact with a portion having high rigidity. Thereby, since the rigidity of the vibration surface can be increased effectively, resonance with other components can be avoided while suppressing an increase in mass. As a result, the noise of the power unit can be suppressed.

<< Third Embodiment >>
The power converter device 20 which concerns on other embodiment of this invention is demonstrated using FIG. In the present embodiment, the configuration of the upper housing 23a is different from the first embodiment described above. Other configurations are the same as those of the first embodiment described above, and the descriptions of the first and second embodiments are incorporated as appropriate. 6A shows a plan view of the upper housing 23a, and FIG. 6B shows a cross-sectional view taken along the line VI-VI in FIG. 6A. Note that a surface along the normal direction of the paper surface of FIG. 6A is a cross section shown in FIG.

  The upper housing 23a has a thick portion 230 centered on the central portion A. The thickness of the thick part 230 is thicker than the thickness of other parts other than the thick part 230. The part other than the thick part 230 includes the outer peripheral part of the surface of the upper housing 23a. The thick part 230 is configured to be integrated with the upper casing 23a. That is, the upper housing 23a is configured such that the antinode portion of the vibration is thicker than the other portions other than the antinode in the cross section along the VI-VI line. The thickness of the upper housing 23a is the thickest at the vibration antinode, and gradually decreases toward the outer periphery.

  Thereby, this embodiment can increase the rigidity of the surface used as the vibration surface of the upper housing | casing 23a effectively, and can suppress the deformation amount by a vibration. Also, resonance with other parts can be avoided. As a result, the noise of the power unit can be suppressed.

<< 4th Embodiment >>
The power converter device 20 which concerns on other embodiment of this invention is demonstrated using FIG. This embodiment differs from the first embodiment described above in that ribs 72a to 72c are provided on the upper housing 23a. Other configurations are the same as those of the first embodiment described above, and the descriptions of the first and second embodiments are incorporated as appropriate. FIG. 7A shows a plan view of the upper housing 23a, and FIG. 7B shows a cross-sectional view taken along line VII-VII in FIG. 7A. Note that a surface along the normal direction of the paper surface of FIG. 7A is a cross section shown in FIG. 7B.

  Ribs 71a to 71c and ribs 72a to 72c are provided on the surface of the upper housing 23a. The ribs 72a to 72c are configured to have circular shapes with different radii. The rib 72a has the smallest diameter and the rib 72c has the largest diameter. The center points of the circular ribs 72a to 72c are the same, and the center points of the ribs 71a to 71c are located at the center portion A of the surface of the upper housing 23a. That is, the ribs 71a to 71c are formed along a circle centered on the central portion A of the surface of the upper housing 23a.

  In the present embodiment, the upper housing 23a is provided with ribs 72a to 72c at the antinode portions of vibration in a cross section along the line VII-VII. Thereby, the rigidity of the belly part of the upper housing | casing 23a increases. In the present embodiment, even if the thick portion 230 is not provided in the housing 23 as in the third embodiment, the same effect as the thick portion 230 can be exhibited by the ribs 72a to 72c. Moreover, when manufacturing the upper housing | casing 23a which has the thick part 230 like 3rd Embodiment by casting, high quality control is calculated | required. On the other hand, the upper housing 23a can be easily manufactured by casting by providing the ribs 72a to 72c on the upper housing 23a instead of the thick portion 230 as in the present embodiment. Therefore, the casting quality of the upper housing 23a can be maintained without increasing quality control more than necessary.

  Said rib 72a-72 corresponds to the "2nd rib" of this invention.

<< 5th Embodiment >>
The power converter device 20 which concerns on other embodiment of this invention is demonstrated using FIG. In the present embodiment, the shapes of the ribs 71a to 71c are different from those of the first embodiment described above. Other configurations are the same as those of the first embodiment described above, and the descriptions of the first and second embodiments are incorporated as appropriate. 8A shows a plan view of the upper housing 23a, FIG. 8B shows a cross-sectional view taken along the line VIIIa-VIIIa of FIG. 8A, and FIG. 8C shows FIG. 8A. Sectional drawing which follows the VIIIb-VIIIb line of is shown. In addition, the cross section which follows the VIIIa-VIIIa line and the cross section which follows the VIIIb-VIIIb line is a surface which makes the direction which goes to the volt | bolt 60 located in the four corners from the center part A of the upper housing | casing 23a as a normal line direction. The cross section along the line VIIIa-VIIIa is a surface closer to the central part A than the cross section along the line VIIIb-VIIIb between the central part A of the upper housing 23a and the bolts 60 located at the four corners. .

  The ribs 71 a to 71 c have the thickest central portion A and gradually become thinner toward the bolt 60. In other words, the ribs 71a to 71c are configured to be thicker as they are closer to the belly portion of the upper housing 23a. For example, regarding the cross section of the rib 71c, Sa> Sb is established when the area of the cross section along the line VIIIa-VIIIa is Sa and the area Sb of the cross section along the line VIIIb-VIIIb. That is, the rib 71c is formed so that the cross-sectional area when the rib 71c is cut along the section VIIIa-VIIIa line is larger than the cross-sectional area when the rib 71c is cut along the section VIIIb-VIIIb line. The rib 71a and the rib 71b are also formed in the same manner as the rib 71c.

  In the present embodiment, the ribs 72a to 72c are configured so that the area of the cross section of the ribs 72a to 72c increases as the area of the rib on the surface of the upper housing 23a is closer. Thereby, even if this embodiment does not provide the thick part 230 in the housing | casing 23 like 3rd Embodiment, the effect similar to the thick part 230 can be exhibited by the ribs 71a-71c.

DESCRIPTION OF SYMBOLS 20 ... Power converter 21 ... Electronic component 23 ... Case 23a ... Upper case 23b ... Lower case 60 ... Bolt 71, 71a-71c, 72a-72c ... Rib

Claims (6)

A power conversion device having an electronic component and a housing for housing the electronic component ;
A power unit comprising a power device fastened to the housing,
The housing includes a first member and a second member, and a fastening member that fastens the first member and the second member;
The first member has a fastening portion fastened by the fastening member on the surface of the first member, and a rib,
The rib has a first rib formed along a direction from a predetermined position on the surface toward the fastening portion,
The power unit, wherein the eigenvalue of the casing is separated from the eigenvalue of the power unit . The power unit according to claim 1, wherein
The fastening portion corresponds to a node of a vibration wave generated by the vibration of the first member,
The power unit according to claim 1, wherein the predetermined position corresponds to an antinode of the vibration wave. The power unit according to claim 1 or 2,
The power unit according to claim 1, wherein the first rib is in contact with the fastening portion at an end of the first rib. The power unit according to any one of claims 1 to 3,
The first member is formed in the first cross section so that the thickness of the predetermined position is thicker than the thickness of a portion other than the predetermined position,
The power unit according to claim 1, wherein the first cross section is a surface along a normal direction of the surface. The power unit according to any one of claims 1 to 3,
The power unit according to claim 1, wherein the rib includes a second rib formed along a circle centered on the predetermined position on the surface. The power unit according to any one of claims 1 to 3,
The first rib is formed such that a cross-sectional area when the first rib is cut along a second cross section is larger than a cross-sectional area when the first rib is cut along a third cross section;
The second cross section and the third cross section are surfaces whose normal direction is a direction from the predetermined position toward the fastening portion,
The second cross-section, between a position of said fastening portion to the predetermined position, power unit, characterized in that than the third cross-section is a surface closer to the predetermined position.

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