JP2006335098A - Design cover, and hybrid vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce noise at a high frequency side generated by the operation of a high-voltage motor in a hybrid vehicle. <P>SOLUTION: A design cover 30 is provided above the high-voltage motor disposed in the interior of an engine room of the hybrid vehicle. The design cover is equipped with a sound absorption material 32 put on at least a part of the surface facing the high-voltage motor in the design cover 30. The noise at the high frequency side is reduced since the sound absorption material 32 absorbs the radiation noise radiated from the high-voltage motor. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a hybrid vehicle and a design cover of a high voltage motor mounted on the hybrid vehicle, and more particularly to a sound absorbing structure that absorbs noise generated during operation of the high voltage motor.

  The positional relationship of several parts arrange | positioned inside the engine room 102 of the hybrid vehicle 100 is demonstrated using FIG. A hybrid front unit 106 is disposed in the engine room 102. In the hybrid front unit 106, an engine 108 and a high voltage motor 110 are integrated, and the high voltage motor 110 is arranged beside the engine 108. Above the high-voltage motor 110, a power control unit (hereinafter referred to as PCU) 112 is installed. The PCU 112 includes an inverter (not shown), and the inverter is electrically connected to the high voltage motor 110 via a high voltage cable (not shown). The inverter is connected to a high voltage power supply (not shown), and power is supplied from the high voltage power supply. The inverter converts the frequency of the supplied power and then supplies power to the high voltage motor 110. A design cover 116 is attached above the PCU 112 so as to cover the entire PCU 112 so that the design applied to the surface of the design cover 116 from above the engine room 102 can be seen.

  Inside the engine room 100, a sound absorbing material for absorbing noise generated by the operation of the engine is attached. For example, it is attached to the back of the hood panel 105 (see Patent Document 1), the upper part of the engine 108 (see Patent Document 2), and the like. These sound absorbing materials mainly absorb noise having a frequency (1 to 2 kHz) of noise generated during operation of the engine 108.

JP 2001-233249 A JP 2003-27958 A

  However, in hybrid vehicle 100, noise is also generated when high voltage motor 110 operates in addition to engine 108. Since this noise is a noise on the high frequency side (approximately 5 kHz) compared to the noise generated during operation of the engine 108, it is difficult to effectively absorb the sound with the already installed sound absorbing material.

  In recent years, a hybrid vehicle is required to be as quiet as a gasoline vehicle. For this reason, it is necessary to reduce the noise on the high frequency side generated during the operation of the high voltage motor 110 as well as the noise on the low frequency side generated during the operation of the engine 108.

  Therefore, it is conceivable to add a sound absorbing material that absorbs noise on the high frequency side. However, the sound absorbing material that absorbs noise on the low frequency side is already installed in various places inside the engine room 100, and the sound absorbing material There is almost no space for adding materials. Further, since it is necessary to absorb low-frequency noise generated during engine operation, it is difficult to change the already installed sound-absorbing material to a sound-absorbing material that absorbs high-frequency noise.

  The present invention has been made in view of the above problems of the prior art, and an object thereof is to provide a design cover that absorbs noise generated during operation of a high-voltage motor.

  The present invention relates to a design cover provided above a high voltage motor disposed inside an engine room of a hybrid vehicle, and a sound absorbing material attached to at least a part of a surface of the design cover facing the high voltage motor. The sound absorbing material is characterized by absorbing sound radiated from the high voltage motor.

  Here, it is preferable that the sound absorbing material absorbs sound having a frequency in a specific band.

  Furthermore, the sound absorbing material is preferably formed from PET (polyethylene terephthalate).

  The thickness of the sound absorbing material is determined according to the frequency of the sound to be absorbed.

  In addition, the present invention is a hybrid vehicle including a hybrid front unit including a high voltage motor, and includes any one of the design covers described above.

  According to the present invention, the sound absorbing material affixed to the surface of the design cover facing the high voltage motor absorbs the radiated sound radiated from the high voltage motor, which is generated during the operation of the high voltage motor. Noise is reduced.

  Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a layout diagram of components in an engine room 12 of a hybrid vehicle 10 according to the present embodiment. The hybrid vehicle 10 includes a hybrid front unit 20, a power control unit (hereinafter referred to as PCU) 26, and a design cover 30 inside the engine room 12.

  The hybrid front unit 20 includes an engine 22 and a high-voltage motor 24, and both have a function of generating the driving force of the hybrid vehicle 10. The hybrid front unit 20 is disposed substantially at the center of the engine room 12. The hybrid front unit 20 includes an engine 22 and a high voltage motor 24, and each is arranged side by side.

  The PCU 26 is disposed inside a housing 27 disposed above the high voltage motor 24. The PCU 26 includes an inverter (not shown). The inverter is electrically connected to a high voltage motor 24 and a high voltage power source (not shown) via a high voltage cable (not shown). The inverter has a function as a power converter that converts a high-voltage direct current of a high-voltage power supply into an alternating current and supplies the alternating current to the high-voltage motor 24.

  The design cover 30 is attached so as to cover the upper portion of the housing 27. In the design cover 30, the vehicle right side (lower left side in FIG. 1) of the hybrid vehicle 10 has a box shape in which the back surface (the surface viewed from the back of the paper surface in FIG. 1) is opened. The design cover 30 is attached so that the housing of the PCU 26 can be accommodated in the box. A design such as a manufacturer's logo mark is applied to the surface of the design cover 30 so that the design applied to the surface of the design cover 30 from above the engine room 12 can be seen.

  FIG. 2 shows a front view of the design cover 30 when the design cover 30 shown in FIG. 1 is turned upside down with the traveling direction of the hybrid vehicle 10 as an axis. In the design cover 30, the hatched area in FIG. 2 is a box-shaped part, and the sound absorbing material 32 is attached to this part. The design cover 30 is installed so that the sound absorbing material 32 contacts at least a part of the casing 27 of the PCU 26. For example, the design cover 30 is installed so that the housing of the PCU 26 is in contact with a region (referred to as a contact region 34) surrounded by a one-dot chain line in FIG.

  The sound-absorbing material 32 is formed by forming PET fibers created by fiberizing a PET (polyethylene terephthalate) resin into a mat shape having a thickness of about 20 mm. The PET fiber has a fiber diameter of 0.5 to 20 denier and a fiber length of 10 to 100 mm. In the present embodiment, since the frequency of the sound generated by the operation of the high voltage motor 24 is approximately 5 kHz, the thickness of the sound absorbing material 32 is determined so as to absorb the sound having the frequency of 5 kHz. ing. In addition, when the sound absorbing material 32 is formed of PET fiber, the thicker the sound absorbing material 32 is, the higher the frequency of sound is absorbed. This is the end of the description of the configuration.

  Then, the effect | action in the design cover 30 in this Embodiment is demonstrated. In the hybrid front unit 20, sound generated by the operation of the high voltage motor 24 is radiated to the outside through the casing of the high voltage motor 24 (hereinafter referred to as radiated sound). The radiated sound spreads from the high voltage motor 24, and a part thereof reaches the back side of the design cover 30. The radiated sound reaching the back side of the design cover 30 is absorbed by the air between the fibers of the sound absorbing material 32 absorbing the sound energy.

  As described above, according to the present embodiment, the sound absorbing material 32 provided at the position sandwiched between the design cover 30 and the casing 27 of the PCU 26 absorbs the radiated sound, and thus is generated during the operation of the high voltage motor. Noise is reduced.

  In the present embodiment, PET fibers are used as the sound absorbing material 32. However, the material of the sound absorbing material 32 is not limited to PET fiber as long as it absorbs sound having a frequency of about 5 kHz generated by the operation of the high voltage motor 24. For example, the back of the design cover 30 may be a urethane foam whose thickness is adjusted, which is affixed with a double-sided tape.

  In the present embodiment, the sound absorbing material 32 is provided on the back surface of the design cover 30 at a portion that directly contacts the casing 27 of the PCU 26. However, the noise absorbing effect may be improved by providing the sound absorbing material 32 not only on a part of the design cover 30 but also on the entire back surface.

  In the present embodiment, the thickness of the sound absorbing material 32 is adjusted in accordance with the frequency of the sound to be absorbed. However, not only the thickness of the sound absorbing material 32 but also the fiber diameter or fiber density can be adjusted according to the frequency of the sound to be absorbed. For example, it is possible to increase the sound absorption rate on the high frequency side by increasing the fiber density or decreasing the fiber diameter.

  In the present embodiment, a sound absorbing material 32 is attached to the back of the design cover 30 in order to absorb the high frequency (about 5 kHz) radiated sound generated from the high voltage motor 24 for driving the hybrid vehicle 10. However, the design cover 30 according to the present invention can be applied to any high-voltage motor that generates sound having a frequency on the high-frequency side, even if it is a high-voltage motor that is used for purposes other than vehicle driving.

It is an arrangement plan of each device in an engine room in an embodiment of the present invention. It is the figure which looked at the design cover in embodiment of this invention from the back. It is an arrangement plan of each device in an engine room in the prior art.

Explanation of symbols

  10 hybrid vehicle, 12 engine room, 20 hybrid front unit, 22 engine, 24 high voltage motor, 26 power control unit, 30 design cover, 32 sound absorbing material, 34 contact area.

Claims (5)

A design cover provided above a high-voltage motor disposed in an engine room of a hybrid vehicle,
At least a part of the surface facing the high voltage motor in the design cover is provided with a sound absorbing material pasted,
The design cover is characterized in that the sound absorbing material absorbs the sound emitted from the high voltage motor. The design cover according to claim 1,
The design cover characterized in that the sound absorbing material absorbs sound of a frequency in a specific band. The design cover according to claim 2,
The design cover, wherein the sound absorbing material is made of PET (polyethylene terephthalate). The design cover according to claim 1,
The design cover, wherein the thickness of the sound absorbing material is determined according to the frequency of the sound to be absorbed. A hybrid vehicle including a hybrid front unit with a high voltage motor,
A hybrid vehicle comprising the design cover according to any one of claims 1 to 4.

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