JP6237600B2 - bracket - Google Patents

Description

  This specification discloses the bracket which fixes an electronic device to the transaxle mounted in the vehicle.

  Patent Document 1 discloses a technique for mounting a power converter on a transaxle. The power converter is fixed to the transaxle via a bracket. The bracket includes a vibration isolation member. The vibration isolating member suppresses the vibration of the transaxle from being transmitted to the power converter.

JP 2014-168356 A

  The transaxle is subjected to vibrations of various frequencies. Wide frequency range of vibration applied to the transaxle. The vibration isolating member has a resonance frequency. If the resonance frequency of the vibration isolating member belongs to the wide frequency band, the vibration isolating member cannot absorb vibration. In the conventional technique, it is necessary to select a vibration isolating member that does not have a resonance frequency in the wide frequency band, but it is actually difficult.

  The present specification discloses a technique for suppressing resonance of a vibration isolating member generated by vibration of a transaxle.

  The technique described in this specification was created based on the viewpoint that the frequency band of vibration applied to the transaxle differs depending on the vibration direction. As will be described in detail later, the vibration in the longitudinal direction of the vehicle has a high frequency (high band), whereas the vibration in the vertical and horizontal directions of the vehicle has a low frequency band (low band). Therefore, as long as the vibration isolator has a resonance frequency higher than the high band for vibration in the front-rear direction, the resonance frequency for vibration in the vertical and horizontal directions may be included in the high band, It has been found that vibrations can be absorbed in all directions by the vibration isolator as long as it is higher.

  The bracket disclosed in this specification is a bracket that fixes an electronic device to a transaxle, and the resonance frequency with respect to the vehicle longitudinal vibration generated in the transaxle is the same as the vehicle vertical and horizontal vibration generated in the transaxle. An anti-vibration member having a frequency higher than the resonance frequency is provided.

  The inventors have found that the main generation factor of the longitudinal vibration generated in the transaxle is different from the main generation factor of the vertical and horizontal vibrations of the vehicle. That is, while the vehicle is traveling, vibrations according to the road surface condition are generated in the transaxle in addition to engine vibration in the vertical and horizontal directions of the vehicle.

  On the other hand, in the longitudinal direction of the vehicle, in addition to the vibration of the engine, a vibration corresponding to the force that the transaxle receives from the axle that extends from the transaxle in the lateral direction of the vehicle is generated in the transaxle. More specifically, when the wheel passes through the uneven portion of the road surface, the wheel instantaneously leaves the road surface and idles temporarily and lands in a state where the rotation is maintained. When the wheel lands while the wheel is rotating, the wheel receives a force in the counter-rotating direction of the wheel from the road surface. As a result, the transaxle connected to the wheels via the axle extending in the left-right direction of the vehicle generates vibrations in the vehicle front-rear direction due to the force received by the wheels. The inventors have found that the main vibration frequency band in the vehicle longitudinal direction applied to the transaxle is higher than the main vibration frequency band in the vertical and horizontal directions of the vehicle.

  According to the above configuration, since the resonance frequency of the vibration isolation member for vibration in the front-rear direction is higher than the resonance frequency of the vibration isolation member for vibration in the vertical and horizontal directions, vibration in a relatively high frequency band in the front-rear direction of the vehicle is achieved. In contrast, the occurrence of resonance in the vibration isolating member can be suppressed. On the other hand, by setting the resonance frequency for vibrations in the vertical and horizontal directions of the vehicle to be relatively low, it is possible to suppress the occurrence of resonance in the vibration isolating member with respect to engine vibrations.

  It is preferable that the vibration isolating member includes a portion that mainly absorbs vibrations in the longitudinal direction of the vehicle and a portion that mainly absorbs vibrations in the vertical and horizontal directions of the vehicle.

  It is preferable that the rigidity of the portion that absorbs vibration in the longitudinal direction of the vehicle is higher than the rigidity of the portion that absorbs vibration in the vertical and horizontal directions of the vehicle.

  According to this configuration, it is possible to easily change the resonance frequency for the vibration in the longitudinal direction of the vehicle and the resonance frequency for the vibration in the vertical and horizontal directions of the vehicle.

  According to the technology disclosed in this specification, it is possible to suppress vigorous vibration of an electronic device mounted on a vehicle. As a result, the lifetime of the electronic device can be extended.

It is a perspective view which shows the device layout in an engine compartment. It is a side view of a transaxle and a power converter. It is a longitudinal cross-sectional view of a bracket. It is a graph showing the vibration of a vehicle front-back direction and the resonance magnification of a front-back vibration isolator. It is a graph showing the vibration of a vehicle up-down and left-right direction, and the resonance magnification of a front-back vibration isolator.

  As shown in FIG. 1, the brackets 12 and 32 of the embodiment are applied to a hybrid vehicle 100 that includes both a motor 50 (see FIG. 2) and an engine 97 for traveling. Hereinafter, hybrid vehicle 100 may be simply referred to as “vehicle 100”. The brackets 12 and 32 fix the power converter 10, which is an electronic device, to the transaxle 3. The power converter 10 is a power control unit, for example, and supplies power to the motor 50. It should also be noted that each figure represents a simplified shape of the device within the front compartment 94. Further, the x-axis in the figure corresponds to the front of the vehicle, the y-axis corresponds to the left direction of the vehicle, and the z-axis corresponds to the upper side of the vehicle.

  As shown in FIG. 1, main devices mounted in the front compartment 94 are an engine 97, a transaxle 3, a sub-battery 6, a radiator 96, and a power converter 10. In addition, the code | symbol 92 shows a relay box and the code | symbol 93 shows the compressor of an air-conditioner.

  As shown in FIG. 2, the transaxle 3 includes a transmission (not shown), a motor 50, a differential gear 52, and a power distribution mechanism 54. The transmission amplifies the output torque of the motor and engine. The motor 50 is a drive source for driving the wheels. When the vehicle 100 travels a curve, the differential gear 52 transmits the power of the motor 50 and the engine 97 to the front wheels while giving a rotational speed difference between the left and right front wheels. The differential gear 52 has a main shaft 52 a that extends in the left-right direction of the vehicle 100 and is connected to a front wheel of the vehicle 100. The power distribution mechanism 54 combines / distributes the output torque of the engine 97 and the output torque of the motor 50. The power distribution mechanism 54 combines the output torque of the engine 97 and the output torque of the motor 2 and outputs the resultant to the differential gear 52. The power distribution mechanism 54 divides the output torque of the engine 97 according to the situation and transmits it to the differential gear 52 and the motor 50. In this case, the hybrid vehicle 100 generates electric power by the motor 50 while traveling with engine torque. The hybrid vehicle 100 also generates power by the motor 50 using deceleration energy during braking. The battery is charged with the power obtained from the power generation. The engine 97 and the transaxle 3 are fixed to a side frame 95 (side member) constituting a chassis frame.

  The upper surface 3a of the transaxle 3 is inclined forward of the vehicle. The power converter 10 is fixed to the upper surface 3a. The power converter 10 converts the supplied DC power into AC power from the main battery stored in the rear seat or in the rear compartment via a battery cable, and supplies the AC power to the motor 50. Thereby, the power converter 10 controls the motor 50.

  The power converter 10 is fixed to the transaxle 3 by a front bracket 12 and a rear bracket 32. As shown in FIG. 3, the front bracket 12 fixes the front side of the vehicle 100 of the power converter 10 to the transaxle 3. The front bracket 12 includes a main body 18, two collars 22 and 24, and a vibration isolation member 20. The main body 18 is made of metal such as stainless steel. A lower end portion of the main body 18 extends along the upper surface 3 a and is fixed to the upper surface 3 a via a screw 14. The main body 18 extends substantially vertically upward from the upper surface 3a. Near the upper end of the main body 18, a through hole 18 a that penetrates the main body 18 is disposed.

  The vibration isolating member 20 is inserted into the through hole 18a via the collar 24. The vibration isolating member 20 is made of rubber. The anti-vibration member 20 includes a front / rear anti-vibration unit 20a and an upper / lower / left / right anti-vibration unit 20b. The top / bottom / left / right vibration isolator 20b has a cylindrical shape. The top / bottom / left / right vibration isolator 20b is inserted into the through hole 18a and makes a round along the inside of the through hole 18a. The up / down / left / right vibration isolator 20b mainly absorbs the vibration of the transaxle 3 in the up / down / left / right direction of the vehicle 100 to suppress the vibration of the power converter 10.

  The front / rear vibration isolator 20a is disposed at the front end of the vehicle 100 of the top / bottom / left / right vibration isolator 20b. The front and rear vibration isolator 20a has an annular shape. The inner diameter of the front / rear vibration isolator 20a is equal to the inner diameter of the top / bottom / left / right anti-vibration part 20b, and the outer diameter of the front / rear vibration isolator 20a is larger than the diameter of the through hole 18a. The front and rear vibration isolator 20a is pressed and compressed toward the front surface of the main body 18 by a screw 16 described later. The front / rear vibration isolator 20a mainly absorbs vibration of the transaxle 3 in the front / rear direction of the vehicle 100 and suppresses vibration of the power converter 10.

  The rigidity of the front / rear vibration isolator 20a is higher than that of the upper / lower / left / right anti-vibration part 20b. Thereby, the resonance frequency of the front and rear vibration isolator 20a is higher than the resonance frequency of the top, bottom, left and right vibration isolator 20b. For example, by increasing the axial length of the screw 16 of the front and rear vibration isolator 20a and increasing the compression force by the screw 16, the rigidity of the front and rear vibration isolator 20a is increased. Alternatively, the rigidity of the front and rear vibration isolator 20a may be increased by increasing the cross-sectional area of the screw 16 of the front and rear vibration isolator 20a in the axial direction. When the cross-sectional area of the screw 16 in the axial direction is increased, the length of the collars 22 and 24 in the axial direction of the screw 16 may be increased.

  FIG. 4 shows the resonance magnification RC1 with respect to the frequency of the front and rear vibration isolator 20a. FIG. 5 shows the resonance magnification RC2 with respect to the frequency of the top / bottom / left / right vibration isolator 20b. 4 and 5, the horizontal axis represents the frequency of vibration, and the right vertical axis represents the resonance magnification. The right vertical axis is effective for the resonance magnifications RC1 and RC2. The resonance magnification RC1 of the front / rear vibration isolator 20a is set to take the highest value at a frequency slightly higher than 70 Hz. That is, the resonance frequency of the front and rear vibration isolator 20a is slightly higher than 70 Hz. On the other hand, the resonance magnification RC2 of the top / bottom / left / right vibration isolator 20b is set to take the highest value at a frequency slightly higher than 50 Hz. That is, the resonance frequency of the top / bottom / left / right vibration isolator 20b is larger than 50 Hz and smaller than 70 Hz. A screw 16 is inserted inside the vibration isolation member 20 via a collar 22. The screw 16 is fastened to the front end of the power converter 10 to fix the power converter 10 and the main body 18. Further, when the screw 16 is fastened to the power converter 10, the front and rear vibration isolator 20 a sandwiched between the collars 22 and 24 is compressed.

  As shown in FIG. 3, the rear bracket 32 fixes the rear side of the vehicle 100 of the power converter 10 to the transaxle 3. The rear bracket 32 has the same configuration as the front bracket 12. However, the mounting direction of the rear bracket 32 in the front-rear direction of the vehicle 100 is opposite to the mounting direction of the front bracket 12. The rear bracket 32 includes a main body 38 corresponding to the main body 18, two collars 42 and 44 corresponding to the two collars 22 and 24, and a vibration isolation member 40 corresponding to the vibration isolation member 20. The main body 38 is fixed to the upper surface 3 a via a screw 34. Near the upper end of the main body 38, a through hole 38 a that penetrates the main body 38 is disposed.

  The top / bottom / left / right vibration isolator 40b of the anti-vibration member 40 has a cylindrical shape and makes a round along the inside of the through hole 38a. The top / bottom / left / right vibration isolator 40b mainly absorbs vibrations of the vehicle 100 of the transaxle 3 in the top / bottom / left / right directions to suppress the vibration of the power converter 10 in the same manner as the top / bottom / left / right vibration isolator 20b. The front / rear vibration isolator 40a is disposed at the rear end of the vehicle 100 of the top / bottom / left / right vibration isolator 40b. The inner diameter of the front / rear vibration isolator 40a is equal to the inner diameter of the upper / lower / left / right vibration isolator 40b, and the outer diameter of the front / rear vibration isolator 40a is larger than the diameter of the through hole 38a. The front / rear vibration isolator 40a is pressed toward the vehicle rear side surface of the main body 38 by a screw 36 described later. The front / rear vibration isolator 40a mainly absorbs vibrations of the transaxle 3 in the front / rear direction of the vehicle 100 and suppresses vibrations of the power converter 10 in the same manner as the front / rear vibration isolator 20a. The rigidity of the front / rear vibration isolator 40a is higher than the rigidity of the upper / lower / left / right anti-vibration part 40b, and the resonance frequency of the front / rear vibration isolator 40a is higher than the resonance frequency of the upper / lower / left / right anti-vibration part 40b. A screw 36 is inserted inside the vibration isolation member 40 through a collar 42. The screw 36 is fastened to the power converter 10 to fix the power converter 10 and the main body 38.

  With reference to FIGS. 4 and 5, the vibration of the transaxle 3 that occurs when the vehicle 100 travels will be described. 4 and 5, the horizontal axis represents the frequency of vibration, and the left vertical axis represents acceleration. The left vertical axis is effective for the broken lines VC, VE1, VI, and VE2. As shown in FIG. 4, a vibration VE <b> 1 corresponding to the driving of the engine 97 is generated in the longitudinal direction of the vehicle 100 of the transaxle 3. The frequency and acceleration of the vibration VE1 change when the drive of the engine 97 changes. The higher the frequency of the vibration VE1, the higher the acceleration of the vibration VE1. Further, in the front-rear direction of the vehicle 100 of the transaxle 3, a vibration VC is generated due to the force that the front wheels receive from the road surface. Specifically, when the wheel passes through the uneven portion of the road surface, the wheel instantaneously leaves the road surface and idles temporarily and lands in a state where the rotation is maintained. The force from the road surface that is received when the wheels land while the wheels are rotating is transmitted to the transaxle 3 via the main shaft 52a. Since the axle 52a extends from the transaxle 3 in the left-right direction of the vehicle, the force received from the road surface of the wheel acts in the vehicle front-rear direction of the transaxle 3. Thereby, vibration VC according to the road surface condition is generated in the transaxle 3 in the vehicle longitudinal direction. The vibration VC has a higher acceleration at a frequency of 70 Hz or less than the vibration VE1.

  In the vibration isolating members 20 and 40, the vibration of the transaxle 3 in the front-rear direction of the vehicle 100 is suppressed by the front and rear vibration isolating portions 20a and 40a. The resonance frequencies of the front and rear vibration isolators 20a and 40a are set to be greater than 70 Hz. Thereby, it is possible to prevent the vibration VC from resonating in the front and rear vibration isolators 20a and 40a when the acceleration is in a high frequency range of 70 Hz or less.

  Further, as shown in FIG. 5, vibration VE <b> 2 corresponding to driving of the engine 97 is generated in the up / down / left / right direction of the vehicle 100 of the transaxle 3. As with the vibration VE1, the frequency and acceleration of the vibration VE2 change when the drive of the engine 97 changes. The higher the frequency of the vibration VE2, the higher the acceleration of the vibration VE2. Further, vibration VI caused by road surface unevenness is generated in the vertical and horizontal directions of the vehicle 100 of the transaxle 3. In the vibration VI, the acceleration at a frequency of 50 Hz or less is higher than that in the vibration VE2. Further, when the vibration VI and the vibration VC are compared, the vibration VC has a higher acceleration in a range where the frequency is higher.

  In the vibration isolation members 20 and 40, the vibration of the transaxle 3 in the vertical and horizontal directions of the vehicle 100 is suppressed by the vertical and horizontal vibration isolation parts 20b and 40b. The resonance frequency of the top / bottom / left / right vibration isolator 20b, 40b is set slightly higher than 50 Hz. As a result, it is possible to prevent the vibration VI from resonating in the upper, lower, left and right vibration isolating portions 20b and 40b when the acceleration is in a high frequency range of 50 Hz or less.

  According to this configuration, the resonance generated in the vibration isolation members 20 and 40 can be suppressed with respect to the vibration of the transaxle 3. Further, by making the rigidity of the front / rear vibration isolator 20a higher than that of the upper / lower / left / right anti-vibration part 20b, the resonance frequencies of the front / rear vibration isolator 20a and the upper / lower / left / right anti-vibration part 20b can be easily changed.

  Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.

  For example, in the anti-vibration member 20, the front and rear anti-vibration unit 20a and the upper, lower, left, and right anti-vibration units 20b may be integrated or separate. In this case, the resonance frequency of the front / rear vibration isolation unit 20a and the upper / lower / left / right vibration isolation unit 20b may be changed by changing the material of the front / rear vibration isolation unit 20a and the upper / lower / left / right vibration isolation unit 20b. The same applies to the vibration isolator 40.

  Further, the shape of the vibration isolating member 20 is not limited to the shape of the above embodiment. For example, the up / down / left / right anti-vibration unit 20b includes a separate anti-vibration unit for the vibration of the transaxle 3 in the vertical direction of the vehicle 100 and an anti-vibration unit for the vibration of the trans-axle 3 in the horizontal direction of the vehicle 100. Also good. The same applies to the vibration isolator 40.

  The anti-vibration member 20 may have a shape such as a sphere or a cube that does not distinguish between the front and rear anti-vibration unit 20a and the upper, lower, left, and right anti-vibration unit 20b. In this case, by applying a force larger than the vertical and horizontal directions of the vehicle 100 in the longitudinal direction of the vehicle 100 of the vibration isolation member 20, the resonance frequency for the vibration of the transaxle 3 in the longitudinal direction of the vehicle 100 is changed. You may make it higher than the resonant frequency with respect to the vibration of the left-right direction.

  The frequency values of the vibrations VE1, VC, VE2, and VI may vary depending on the rigidity of the vehicle 100, the performance of the suspension, and the like. Therefore, the values of the resonance frequencies of the front and rear vibration isolator 20a and the upper and lower left and right vibration isolator 20b can be changed according to the characteristics of the vibrations VE1, VC, VE2, and VI. However, the vibration VC has a higher acceleration at a higher frequency than the vibration VI. For this reason, it is preferable that the resonance frequency of the front-rear vibration isolator 20a is greater than the resonance frequency of the top / bottom / left / right vibration isolator 20b.

  The vibration isolating member 20 is disposed between the main body 18 and the screw 16. However, the vibration isolation member 20 may be disposed at an intermediate position of the main body 18, may be disposed between the main body 18 and the power converter 10, or may be disposed between the main body 18 and the transaxle 3. May be arranged.

  The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or the drawings can achieve a plurality of objects at the same time, and has technical usefulness by achieving one of the objects.

3: transaxle, 3a: upper surface, 10: power converter, 12: front bracket, 20: vibration isolation member, 20a: front / rear vibration isolation unit, 20b: top / bottom / left / right vibration isolation unit, 32: rear bracket, 40: vibration isolation 40a: front / rear vibration isolation unit, 40b: top / bottom / left / right vibration isolation unit, 100: hybrid vehicle

Claims (3)

A bracket for fixing an electronic device to a transaxle,
A bracket including a vibration isolating member having a resonance frequency with respect to vibrations in the longitudinal direction of the vehicle generated in the transaxle higher than a resonance frequency with respect to vibrations in the vertical and horizontal directions of the vehicle generated in the transaxle.   The bracket according to claim 1, wherein the vibration isolation member includes a portion that mainly absorbs vibrations in the front-rear direction and a portion that mainly absorbs vibrations in the vertical and horizontal directions.   The bracket according to claim 2, wherein the rigidity of the portion that absorbs vibration in the front-rear direction is higher than the rigidity of the portion that absorbs vibration in the up-down and left-right directions.

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