JP2010223313A - Sound absorbing cover - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sound absorbing cover having a high sound absorption rate and reducing noise of a power transmission device. <P>SOLUTION: The sound absorbing cover 50 disposed inside a transmission case 21 for reducing noise of the power transmission device 20 for transmitting power from an engine to a driving shaft via a planetary gear mechanism connected to the engine of a vehicle includes a cover body 51 composed as a frame body having at least one opening part 54 and fixed to the transmission case 21, and a sound absorbing material 55 fixed to the cover body 51 so as to block the opening part 54. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention provides a sound absorbing cover for reducing noise of a power transmission device that is disposed in a transmission case and transmits power from a power generation source to a drive shaft via a transmission mechanism connected to the power generation source of the vehicle. About.

  Conventionally, as a sound absorbing structure of a power transmission device, a case accommodating a plurality of gears, a cover having an inner surface facing the outer surface of the case, and the outer surface of the case and the inner surface of the cover are contacted and heated. Then, the thing provided with the sound-absorbing material which expand | swells is known (for example, refer patent document 1).

JP 2006-46418 A

  When the sound absorbing material is arranged between the outer surface of the case and the cover having the inner surface facing the outer surface as in the conventional sound absorbing structure, the amount of the sound absorbing material is used to further reduce the noise of the power transmission device. In order to increase (thickness), it is necessary to increase the size of the cover particularly in the thickness direction. However, there is a limit to the size increase of the cover due to the relationship with the space where the power transmission device is arranged, and in the conventional sound absorbing structure, it is not easy to improve the sound absorption rate by increasing the sound absorbing material.

  In view of the above, the main object of the present invention is to provide a sound-absorbing cover that has a high sound absorption coefficient and can reduce the noise of the power transmission device.

  The sound absorbing cover according to the present invention adopts the following means in order to achieve the main object described above.

The sound absorbing cover according to the present invention is
A sound absorbing cover for reducing noise of a power transmission device that is arranged in a transmission case and transmits power from the power generation source to a drive shaft via a transmission mechanism connected to the power generation source of the vehicle. ,
A cover body configured as a frame having at least one opening and fixed to the transmission case;
A sound absorbing material fixed to the cover body so as to close the opening;
Is provided.

  The cover body of the sound absorbing cover is configured as a frame having at least one opening, and a sound absorbing material is fixed to the cover body so as to close the opening. The cover body is fixed to the transmission case so that a part of the transmission case is covered with the sound absorbing material. Thus, if the sound absorbing material is fixed to the frame-shaped cover body so as to close the opening, the amount (thickness) of the sound absorbing material attached to the transmission case can be increased without increasing the size of the cover body, and the transmission case It is possible to absorb sound waves leaking out from the sound and reflected in the vicinity by the sound absorbing material. Therefore, according to this sound absorbing cover, it is possible to improve the sound absorption rate and further reduce the noise of the power transmission device. Furthermore, by forming the cover main body fixed to the transmission case in a frame shape, the entire sound absorbing cover can be reduced while the sound absorbing material can be firmly fixed to the transmission case.

  The sound absorbing material may be fixed to the inner surface of the cover body so as to be exposed to the outside from the opening. If the sound absorbing material is fixed to the inner surface of the cover body so that the sound absorbing material is exposed to the outside through the opening, and the sound absorbing material is allowed to protrude from the opening, the amount of the sound absorbing material attached to the transmission case ( (Thickness) can be further increased. Further, if the sound absorbing material is fixed to the inner surface of the cover body, the sound absorbing effect can be further enhanced by bringing the sound absorbing material closer to a transmission mechanism such as a noise source in the transmission case, that is, a gear mechanism.

  Further, the transmission case may be composed of a plurality of cases connected to each other, and the cover body is fixed to the transmission case so that a joint portion between the cases is covered by the sound absorbing material. May be. As a result, it is possible to satisfactorily suppress noise leakage from the joints of the cases constituting the transmission case and further reduce the noise of the power transmission device.

  The power transmission device includes, as the transmission mechanism, first and second electric motors arranged in the transmission case, a three-element planetary gear mechanism, a differential mechanism coupled to the drive shaft, and the The planetary gear mechanism may include a gear mechanism that connects the planetary gear mechanism and the differential mechanism. The planetary gear mechanism includes a sun gear connected to a rotation shaft of the first motor, and a second gear of the second motor. You may have a ring gear connected to a rotating shaft, and a planetary carrier connected to the output shaft of the said power generation source. The power transmission device includes, as the transmission mechanism, a torque converter disposed in the transmission case, a stepped automatic transmission, a differential mechanism coupled to the drive shaft, and the difference from the automatic transmission. It may include a gear mechanism that connects the moving mechanism. Furthermore, the power transmission device includes, as the transmission mechanism, a torque converter disposed in the transmission case, a forward / reverse switching mechanism, a belt-type continuously variable transmission, a differential mechanism coupled to the drive shaft, and the A gear mechanism that connects the continuously variable transmission and the differential mechanism may be included.

It is a schematic block diagram which shows an example of the power transmission device 20 with which the sound absorption cover by this invention is applied. 2 is a perspective view showing an external appearance of a power transmission device 20. FIG. It is a perspective view which shows an example of the sound absorption cover 50 which concerns on an Example. 4 is an explanatory view showing a structure of a sound absorbing cover 50. FIG. It is a schematic block diagram which shows the power transmission device 20B which can apply the sound absorption cover 50. FIG. It is a schematic block diagram which shows the power transmission device 20C which can apply the sound absorption cover 50.

  Next, the form for implementing this invention is demonstrated using an Example.

  FIG. 1 is a schematic configuration diagram of a power transmission device 20 to which a sound absorbing cover according to an embodiment of the present invention is applied. A power transmission device 20 shown in the figure is configured as a so-called electric continuously variable transmission connected to an engine 10 mounted on a vehicle, and is joined to a first case 21a and a second case 21b. A transmission case 21 including the third case 21c, two motors MG1 and MG2 housed in the transmission case 21, a three-element planetary gear mechanism 30, a reduction gear mechanism 35, and a counter gear (gear mechanism) 36. And a transmission mechanism including a differential gear 37.

  Each of the motors MG1 and MG2 is configured as a known synchronous generator motor that operates as a generator and can operate as a motor, and is a battery such as a nickel metal hydride secondary battery or a lithium ion secondary battery via an inverter (not shown). Exchange power with (not shown). The planetary gear mechanism 30 is an external gear sun gear 31 connected to the rotation shaft of the motor MG1, and is arranged concentrically with the sun gear 31 and connected to the rotation shaft of the motor MG2 via the reduction gear mechanism 35. A ring gear 32 of an internal gear, a plurality of pinion gears 33 meshing with the sun gear 31 and meshing with the ring gear 32, and a plurality of pinion gears 33 are held to rotate and revolve freely, and to the crankshaft 12 of the engine 10 via the damper 22. This is a single pinion type planetary gear mechanism having a carrier 34 to be connected and performing a differential action with the sun gear 31, the ring gear 32, and the carrier 34 as rotational elements. When the motor MG1 functions as a generator, the planetary gear mechanism 30 distributes the power from the engine 10 input from the carrier 34 to the sun gear 31 side and the ring gear 32 side according to the gear ratio, and the motor MG1 serves as an electric motor. When functioning, the power from the engine 10 input from the carrier 34 and the power from the motor MG1 input from the sun gear 31 are integrated and output to the ring gear 32 side.

  The reduction gear mechanism 35 is an external gear sun gear connected to the rotation shaft of the motor MG2, and an internal gear ring gear 32 that is arranged concentrically with the sun gear and integrated with the ring gear 32 of the planetary gear mechanism 30. And a plurality of pinion gears meshing with the sun gear and meshing with the ring gear so as to rotate and revolve freely and have a carrier fixed to the transmission case (second case 21b) in a non-rotatable manner. It is a planetary gear mechanism. The ring gear 32 of the planetary gear mechanism 30 and the ring gear of the reduction gear mechanism 35 that are integrated with each other are formed with external teeth 32 a, and the external teeth 32 a are connected to a differential gear 37 via a counter gear 36. Has been. The power output to the ring gear 32 and the external teeth 32a is transmitted from the counter gear 36 and the differential gear 37 to the left and right drive shafts 38a and 38b connected to the left and right drive wheels (not shown).

  In the power transmission device 20 configured as described above, the engine 10 is operated and controlled so that the power corresponding to the required torque requested by the driver is output from the engine 10, and all of the power output by the engine 10 is a planet. By driving and controlling the motors MG1 and MG2 so that torque is converted by the gear mechanism 30 and the motors MG1 and MG2, part of the torque (direct torque) output by the engine 10 to the ring gear 32 and the external teeth 32a is obtained. It can transmit and output torque from motor MG2. Further, the power transmission device 20 controls the operation of the engine 10 so that the power corresponding to the sum of the required torque and the electric power necessary for charging / discharging the battery is output from the engine 10, and the engine 10 is accompanied by charging / discharging of the battery. The motors MG1 and MG2 are driven such that all or a part of the power output from the motor is output to the ring gear 32 and the external teeth 32a with torque conversion by the planetary gear mechanism 30 and the motors MG1 and MG2. It can also be controlled. Further, in the power transmission device 20, the motor MG2 can be driven and controlled so that the engine 10 is stopped and torque based on the required torque is output to the ring gear 32 and the external teeth 32a.

  FIG. 2 is a perspective view showing an appearance of the power transmission device 20 described above. As shown in the figure, sound absorbing covers 50 and 60 are fixed to the transmission case 21 in order to reduce the noise of the power transmission device 20. The sound absorbing cover 50 is mainly for absorbing gear noise generated in gear mechanisms such as the planetary gear mechanism 30, the reduction gear mechanism 35, the counter gear 36, and the differential gear 37 in the transmission case 21. In the embodiment, the sound absorbing cover 50 uses bolts or the like (not shown) so as to mainly cover the differential gear 37, the counter gear 36, and the planetary gear mechanism 30 so as to cover the joint portion between the first case 21a and the second case 21b. It is fixed to the transmission case 21. The sound absorbing cover 60 is fixed to the transmission case 21 using a bolt or the like (not shown) so as to mainly cover the planetary gear mechanism 30 and the reduction gear mechanism 35 so as to cover the joint portion between the first case 21a and the second case 21b. Is done. Here, although the sound absorbing cover 60 is different from the sound absorbing cover 50 in terms of shape and size, the sound absorbing cover 60 basically has the same structure as the sound absorbing cover 50. Therefore, referring to FIG. 3 and FIG. The sound absorbing cover 50 will be described.

  As shown in FIGS. 3 and 4, the sound absorbing cover 50 includes a cover main body 51 and a sound absorbing material 55 fixed to the cover main body 51. The cover main body 51 of the embodiment is formed as a frame-like body from a polyamide-based resin or the like, and an opening defined by the outer frame portion 52, the cross beam portion 53, and the outer frame portion 52 and the cross beam portion 53. Part 54. The outer frame portion 52 is a portion corresponding to an outer peripheral portion (outline) of a sound absorbing cover made of a conventional resin or the like. Further, the cross beam portion 53 is a portion that connects mutually opposing portions of the outer frame portion 52 in order to maintain the strength of the cover main body 51. As shown in FIGS. 3 and 4, the cover main body 51 of the embodiment has two openings 54 having a relatively large area, which are defined by an outer frame portion 52 and one cross beam portion 53. However, the size and number of openings (the number of cross beams 53) can be arbitrarily determined according to the strength required for the cover body 51, the sound absorption coefficient required for the sound absorbing cover 50, and the like. Further, if necessary, a vertical girder part extending substantially orthogonal to the cross girder part 53 may be formed in the cover main body 51. The outer frame portion 52 and the cross beam portion 53 of the cover main body 51 are formed with mounting seats used for fixing to the transmission case 21, mounting seats such as various cables (not shown), and the like.

  And the sound-absorbing material 55 which is felt, a highly functional batting material (nonwoven fabric), etc. is fixed to the inner surface of the cover main body 51. In the embodiment, a plurality of pieces or a plurality of locations (see circles in FIG. 4) on the outer periphery of the sound absorbing material 55 having a certain thickness are crimped to the inner surfaces of the outer frame portion 52 and the cross beam portion 53, thereby covering the cover body 51. A sound absorbing material 55 is fixed so as to close each opening 54 on the inner surface of the sound. Accordingly, each sound absorbing material 55 slightly protrudes from the opening 54 so as to bulge outward. A sound insulating material (not shown) made of a material such as an EPDM rubber foam may be attached to the inner surface or the outer surface of the cover main body 51 so as to close the gap between the outer periphery of the opening 54 and the sound absorbing material 55. Thereby, it becomes possible to further suppress the leakage of noise from the inside to the outside of the sound absorbing cover 50.

  As described above, the sound absorbing cover 50 of the embodiment fixed to the transmission case 21 of the power transmission device 20 includes the cover main body 51 configured as a frame body having at least one opening 54, and the opening 54. The cover body 51 is fixed to the transmission case 21 so that the joint portion between the first case 21a and the second case 21b is covered by the sound absorption material 55. The Thus, if the sound absorbing material 55 is fixed to the frame-shaped cover main body 51 so as to close the opening 54, the amount (thickness) of the sound absorbing material 55 attached to the transmission case 21 without increasing the size of the cover main body 51 can be reduced. In addition to the increase, the sound absorbing material 55 can also absorb sound waves that leak from the transmission case 21 and are reflected in the vicinity (in the engine compartment). Therefore, according to the sound absorbing cover 50 of the embodiment, it is possible to improve the sound absorption rate and further reduce the noise of the power transmission device 20. Further, by forming the cover main body 51 fixed to the transmission case 21 in a frame shape, the sound absorbing cover 55 can be firmly fixed to the transmission case 21 and the entire sound absorbing cover 50 can be reduced in weight. Is also possible.

  Further, if the sound absorbing material 55 is fixed to the inner surface of the cover main body 51 so as to be exposed to the outside through the opening 54 and the sound absorbing material 55 is allowed to protrude outside from the opening 54, the sound absorbing material 55 is attached to the transmission case 21. The amount (thickness) of the sound absorbing material can be further increased. Further, if the sound absorbing material 55 is fixed to the inner surface of the cover main body 51, the sound absorbing material 55 is attached to noise sources in the transmission case 21, that is, transmission mechanisms such as the planetary gear mechanism 30, the reduction gear mechanism 35, the counter gear 36, and the differential gear 37. The sound absorption effect can be further enhanced by approaching. Further, when the transmission case 21 is composed of a plurality of cases 21a, 21b, and 21c connected to each other as in the above embodiment, the cover body 51 is covered with the sound absorbing material 55 so that the joint portion between the cases is covered. If it is fixed to the transmission case 21, it is possible to satisfactorily suppress noise leakage from the joint portion between the cases constituting the transmission case 21 and further reduce the noise of the power transmission device 20.

  In the power transmission device 20 described above, the rotation shaft of the motor MG2 and the ring gear 32 of the planetary gear mechanism 30 are connected via the reduction gear mechanism 35. However, the rotation shaft of the motor MG2 and the ring gear of the planetary gear mechanism 30 are connected. 32 may be connected via a transmission having, for example, two shift stages of Hi and Lo, or three or more shift stages. Further, as shown in FIG. 5, the sound absorbing covers 50 and 60 are connected to the torque converter 24, the stepped automatic transmission 25, the counter gear 36, and the drive shafts 38a and 38b disposed in the transmission case 21. The transmission gear 20B may be applied to the power transmission device 20B that includes the differential gear 37 as a transmission mechanism and can transmit the power from the engine 10 to the drive shafts 38a and 38b by shifting the power in multiple stages. Further, as shown in FIG. 6, the above-described sound absorbing covers 50 and 60 include a torque converter 24, a forward / reverse switching mechanism 26, a belt-type continuously variable transmission 40, a counter gear 36, and a drive disposed in the transmission case. The present invention may be applied to a power transmission device 20C that includes a differential gear 37 connected to the shafts 38a and 38b as a transmission mechanism and that can continuously change the power from the engine 10 and transmit it to the drive shafts 38a and 38b.

  Here, the correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problems will be described. That is, in the embodiment, the engine 10 is disposed in the transmission case 21 including the first case 21a, the second case 21b, and the third case 21c and is connected to the engine 10 of the vehicle via the planetary gear mechanism 30 and the like. The power transmission device 20 that transmits the motive power to the drive shafts 38 a and 38 b corresponds to the “power transmission device”, is configured as a frame-like body having at least one opening 54, and is attached to the transmission case 21. The sound absorbing cover 50 including the cover main body 51 to be fixed and the sound absorbing material 55 fixed to the cover main body 51 so as to close the opening 54 corresponds to a “sound absorbing cover”. However, the correspondence between the main elements of these embodiments and modifications and the main elements of the invention described in the column of means for solving the problem is described in the column of means for the embodiment to solve the problem. Therefore, the present invention is not limited to the elements of the invention described in the column of means for solving the problem. In other words, the examples are merely specific examples of the invention described in the column for means for solving the problem, and the interpretation of the invention described in the column for means for solving the problem is described in the description of the column. Should be done on the basis.

  The embodiments of the present invention have been described above using the embodiments. However, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the present invention. Needless to say.

  The present invention can be used in the power transmission device manufacturing industry and the like.

  10 engine, 12 crankshaft, 20, 20B, 20C power transmission device, 21 transmission case, 21a first case, 21b second case, 21c third case, 24 torque converter, 25 automatic transmission, 26 forward / reverse switching mechanism, 30 planetary gear mechanism, 31 sun gear, 32 ring gear, 32a external gear, 33 pinion gear, 34 carrier, 35 reduction gear mechanism, 36 counter gear, 37 differential gear, 38a, 39a drive shaft, 40 continuously variable transmission, 50, 60 sound absorption Cover, 51 Cover body, 52 Outer frame part, 53 Cross girder part, 54 Opening part, 55 Sound absorbing material, MG1 motor, MG2 motor.

Claims (6)

A sound absorbing cover for reducing noise of a power transmission device that is arranged in a transmission case and transmits power from the power generation source to a drive shaft via a transmission mechanism connected to the power generation source of the vehicle. ,
A cover body configured as a frame having at least one opening and fixed to the transmission case;
A sound absorbing material fixed to the cover body so as to close the opening;
A sound absorbing cover. The sound absorbing cover according to claim 1,
The sound absorbing cover is fixed to the inner surface of the cover main body so as to be exposed to the outside from the opening. The sound absorbing cover according to claim 1 or 2,
The transmission case is composed of a plurality of cases connected to each other,
The cover main body is a sound absorbing cover that is fixed to the transmission case so that a joint between the cases is covered with the sound absorbing material. In the sound-absorbing cover according to any one of claims 1 to 3,
The power transmission device includes, as the transmission mechanism, first and second electric motors arranged in the transmission case, a three-element planetary gear mechanism, a differential mechanism coupled to the drive shaft, and the planetary gear. A gear mechanism connecting the mechanism and the differential mechanism;
The planetary gear mechanism includes a sun gear connected to the rotation shaft of the first electric motor, a ring gear connected to the rotation shaft of the second electric motor, and a planetary carrier connected to the output shaft of the power generation source. With sound absorbing cover. In the sound-absorbing cover according to any one of claims 1 to 3,
The power transmission device includes, as the transmission mechanism, a torque converter disposed in the transmission case, a stepped automatic transmission, a differential mechanism coupled to the drive shaft, and the automatic transmission and the differential mechanism. A sound-absorbing cover that includes a gear mechanism that connects the two. In the sound-absorbing cover according to any one of claims 1 to 3,
The power transmission device includes, as the transmission mechanism, a torque converter disposed in the transmission case, a forward / reverse switching mechanism, a belt-type continuously variable transmission, a differential mechanism coupled to the drive shaft, and the continuously variable A sound absorbing cover including a gear mechanism connecting the transmission and the differential mechanism.

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