JP5163388B2 - Drive device for hybrid vehicle - Google Patents

Description

  The present invention includes a differential mechanism having a plurality of rotational elements that can be differentially connected to each other, and an electric motor having an output shaft connected to a predetermined rotational element of the differential mechanism, and is output from the differential mechanism to the electric motor. The present invention relates to a drive device for a hybrid vehicle that generates electric power using the motive power.

  2. Description of the Related Art A hybrid vehicle that includes an internal combustion engine and a motor as a power source and includes a generator to generate power by the internal combustion engine is known. In such a hybrid vehicle, there is known a vehicle that prevents a generator loss by fixing a rotor of a generator with a wet multi-plate brake when power generation by a generator is unnecessary (Patent Document). 1).

JP-A-8-183348

  In the vehicle of Patent Document 1, the brake is driven by a hydraulic servo. Therefore, an oil passage for supplying oil from the hydraulic source to the hydraulic servo is required. Also, control for driving the hydraulic servo is required.

  Accordingly, the present invention provides a hybrid vehicle drive device capable of engaging an engagement member provided on an output shaft of a motor or a rotary element of a differential mechanism with a predetermined engagement object with a simpler configuration than the conventional one. The purpose is to provide.

A drive device for a hybrid vehicle according to the present invention includes a differential mechanism having a plurality of rotating elements that are mutually differential, and an electric motor having an output shaft connected to a predetermined rotating element of the differential mechanism. In a vehicle drive device, the vehicle is movable in an axial direction between an engagement position that is provided on the output shaft and engages in contact with a predetermined engagement target and a release position that is separated from the predetermined engagement target. An engagement member is provided in a power transmission path between the predetermined rotation element and the output shaft, and a torque difference that is a difference between the torque of the output shaft and the torque of the predetermined rotation element is A torque cam mechanism for converting the member into a thrust for driving the member toward the engagement position, and the predetermined engagement target is a case of the drive device fixed to the vehicle .

  According to the drive device of the present invention, the engagement member can be engaged with a predetermined engagement target by utilizing the torque difference generated between the output shaft and the predetermined rotation element. Therefore, there is no need to provide an actuator such as a hydraulic servo. Therefore, the engagement member can be engaged with the predetermined engagement object with a simpler configuration than the conventional one.

Further, according to the drive device of the present invention, when the power generation by the electric motor is unnecessary, the output shaft can be braked by the case, so that energy consumption due to the rotation of the electric motor can be prevented.

In one aspect of the driving apparatus of the present invention, the differential mechanism includes a first rotating element, a second rotating element, and a third rotating element as the predetermined rotating elements as the plurality of rotating elements, The power of the internal combustion engine is transmitted to the two rotation elements and an output member is connected to the third rotation element, and the torque cam mechanism is configured such that the engagement member is A thrust that moves to the engagement position may be generated ( claim 2 ). According to this aspect, the engagement member does not reach the engagement position when the torque difference is less than the predetermined value. Therefore, by appropriately setting the predetermined value, it is possible to prevent the engagement member from being engaged with the predetermined engagement object in vain. In this embodiment, the power of the internal combustion engine is transmitted to the electric motor via the differential mechanism. At this time, the engagement member does not engage with the predetermined engagement target until the torque difference becomes a predetermined value or more. . Therefore, torque can be transmitted from the differential mechanism to the electric motor until the torque difference reaches a predetermined value, and torque transmitted from the differential mechanism to the electric motor can be reduced when the torque difference becomes greater than the predetermined value. Therefore, the torque transmitted from the differential mechanism to the electric motor can be adjusted by adjusting the predetermined value.

In one form of drive system of the present invention may be further provided a biasing means for biasing the engaging member to the release position side (claim 3). In this case, by adjusting the urging force by the urging means, it is possible to adjust the torque difference at which the engaging means engages with a predetermined engagement target.

In one form of the drive device of the present invention, the greater the thrust that is interposed between the engagement member and the predetermined engagement target and drives the engagement member toward the engagement position, the greater the engagement member. And a clutch means for increasing a frictional force generated between the predetermined engagement target and the predetermined engagement target ( claim 4 ). In this case, since the frictional force between the engagement member and the predetermined engagement target can be gradually increased or decreased, the rotation speed of the engagement member can be gradually increased or decreased. Thereby, it is possible to prevent the engaging member from being suddenly braked or suddenly starting to rotate.

  As described above, according to the drive device of the present invention, the engagement member can be engaged with the predetermined engagement target by utilizing the difference between the torque of the output shaft and the torque of the predetermined rotation element. Therefore, there is no need to provide an actuator. Therefore, the engagement member can be engaged with a predetermined engagement object with a simpler configuration than in the past.

  FIG. 1 shows a main part of a driving apparatus according to an embodiment of the present invention. In FIG. 1, the illustration of the opposite part across the rotation axis CL is omitted. A drive device 1 shown in FIG. 1 is mounted on a hybrid vehicle, and includes a transmission shaft 2 that transmits power from an internal combustion engine (not shown), and a motor generator (hereinafter abbreviated as MG) as an electric motor. 3) and a power distribution mechanism 4. The power distribution mechanism 4 is housed in a case 5 that is fixed to the vehicle body of the vehicle. The MG 3 is a well-known device that functions as an electric motor and a generator, and includes a stator 3a, a rotor 3b, and an output shaft 3c. The stator 3a, the rotor 3b, and the output shaft 3c are arranged coaxially. The stator 3a is fixed to the case 5 so as not to rotate. The output shaft 3c is rotatably supported by the bearing 6. The rotor 3b is connected to the output shaft 3c so as to rotate integrally with the output shaft 3c. Further, since the internal combustion engine may be the same as a well-known one mounted on the hybrid vehicle, detailed description thereof is omitted.

  The power distribution mechanism 4 includes a planetary gear device 7 as a differential mechanism. The planetary gear mechanism 7 includes a sun gear S as a first rotating element that is an external gear, a ring gear R as a third rotating element of an internal gear disposed coaxially with the sun gear S, a sun gear S, And a carrier C as a second rotating element that holds the pinion gear P meshing with the ring gear R so as to be able to rotate and revolve around the sun gear S. The carrier C is connected to the transmission shaft 2 so as to rotate integrally. The ring gear R is connected to an output member 8 that outputs power to a device on the downstream side of the power transmission path from the power distribution mechanism 4. The sun gear S is rotatably supported by bearings 9 and 9 on the outer periphery of the transmission shaft 2. The sun gear S is connected to the output shaft 3c of the MG3.

  An engaging member 10 is provided on the output shaft 3c of the MG3. A torque cam mechanism 20 is provided between the engagement member 10 and the sun gear S. That is, the output shaft 3 c is connected to the sun gear S via the engagement member 10 and the torque cam mechanism 20. The engaging member 10 includes a braking portion 10a that protrudes radially outward. The braking portion 10a is provided on the engaging member 10 so as to come into contact with the protruding portion 5a provided on the case 5 when the engaging member 10 moves to the right side in FIG. Therefore, the case 5 corresponds to a predetermined engagement target of the present invention. Moreover, the brake part 10a is provided so that it can brake the engagement member 10 and stop the rotation, when engaging with the protrusion part 5a. The engaging member 10 is attached to the output shaft 3 via the spline mechanism 11 so as not to rotate relative to the output shaft 3c and to move in the direction of the rotation axis CL. As a result, the engagement member 10 can move between the engagement position where the braking portion 10a contacts and engages with the protruding portion 5a and the release position where the braking portion 10a moves away from the protruding portion. Is provided. Further, the engaging member 10 is rotatably supported on the transmission shaft 2 by a bearing 12. As shown in FIG. 1, the case 5 is provided with a return spring 13 as an urging means for urging the engaging member 10 to the left in FIG. A thrust bearing 14 for preventing the return spring 13 from rotating integrally with the engagement member 10 is provided between the engagement member 10 and the return spring 13.

  The torque cam mechanism 20 includes a first cam plate 21 that is fixed to the sun gear S, a second cam plate 22 that is fixed to the engaging member 10, and a plurality of rollers that are interposed between the cam plates 21 and 22. And a ball 23 as a moving body. Each of the cam plates 21 and 22 has a ring shape and is disposed coaxially with the transmission shaft 2. FIG. 2 is a view of the torque cam mechanism 20 as viewed from the direction of arrow II in FIG. As shown in FIG. 2, a plurality of cam grooves 21b and 22b are provided at predetermined intervals in the circumferential direction on the opposing surfaces 21a and 22a of the cam plates 21 and 22, respectively. When the difference between the torque of the sun gear S and the torque of the MG 3 (hereinafter, sometimes referred to as a torque difference) is zero, the cam grooves 21b and 22b face each other at the same position in the circumferential direction, and a ball 23 is held. On the other hand, when a torque difference occurs, the cam plates 21 and 22 are relatively displaced in the circumferential direction. In this case, as shown in FIG. 3, the ball 23 tends to ride on the opposing surfaces 21a and 22a from between the cam grooves 21b and 22b. As a result, a thrust F is generated between the cam plates 21 and 22 so as to keep them away in the axial direction. The thrust F increases as the torque input to the torque cam mechanism 20 from the sun gear S (hereinafter sometimes referred to as input torque) increases, and the torque difference increases accordingly. Note that the torque cam mechanism 20 is configured such that the ball 23 does not ride completely between the opposing surfaces 21a and 22a. As shown in FIG. 1, the sun gear S is provided so as not to move in the direction of the rotation axis CL. Therefore, when the thrust F is generated by the torque cam mechanism 20, the engaging member 10 is driven to the right side in FIG. The torque cam mechanism 20 is provided such that the engagement member 10 moves to the release position in the state shown in FIG. 2, and the engagement member 10 moves to the engagement position in the state shown in FIG.

  As described above, the engaging member 10 is biased to the left side in FIG. Therefore, when the thrust F generated by the torque cam mechanism 20 exceeds the urging force of the return spring 13, the engagement member 10 starts to move from the release position to the right side in FIG. Therefore, the strength of the return spring 13 is appropriately set according to the input torque that should start driving the engagement member 10 to the engagement position. FIG. 4 shows an example of the relationship between the input torque and the position of the engaging member 10. As shown in FIG. 4, when the input torque becomes the torque T1, the thrust F exceeds the urging force of the return spring 13, and the engagement member 10 starts to move from the released position to the left side in FIG. After that, when the input torque becomes the torque T2 and the engaging member 10 reaches the engaging position, the braking portion 10a and the protruding portion 5a come into contact with each other, whereby the engaging member 10 is braked. Therefore, when the engagement member 10 is driven to the engagement position, the rotation of the sun gear S and the output shaft 3 c can be stopped by the engagement member 10. Therefore, the torque T2 corresponds to the predetermined value of the present invention.

  As described above, according to the drive device 1, the engagement member 10 can be engaged with the case 5 by using the torque difference by the torque cam mechanism 20. Therefore, it is not necessary to provide a separate actuator for driving the engagement member 10. Therefore, the configuration of the driving device 1 can be simplified as compared with the conventional one. Thereby, the drive device 1 can be reduced in size or weight. Further, in the torque cam mechanism 20, since the engaging member 10 does not move to the engaging position until the input torque becomes equal to or greater than the torque T2, and the torque difference corresponding to the torque T2, the engaging member 10 is wasted in the case 5. It can prevent being engaged. Thereby, it is possible to prevent the sun gear S and the output shaft 3c from being braked wastefully. Furthermore, in the drive device 1, by adjusting the strength of the return spring 13, the torque difference at which the engagement member 10 moves to the engagement position can be appropriately adjusted.

  FIG. 5 shows a modified example of the driving device 1 according to one embodiment of the present invention. In FIG. 5, the same reference numerals are given to the same parts as those described above, and the description will be omitted. In addition, FIG. 5 has expanded and shown a part of engaging member 10 and case 5 of this modification. As shown in FIG. 5, in this modified example, a wet multi-plate brake mechanism 30 as a clutch means is provided between the engaging member 10 and the case 5. The brake mechanism 30 includes a friction plate 30 and a brake plate 31. The friction plate 30 is provided on the engagement member 10. A plurality of braking plates 31 (two in FIG. 5) are provided in the case 5 so as to sandwich the friction plate 31 therebetween. The friction plate 30 and the brake plate 31 are provided so as not to rotate around the axis CL and to move in the direction of the axis CL. Then, the engagement member 10 drives the friction plate 30 and the brake plate 31 so that the friction plate 30 is sandwiched between the brake plates 31 when moved to the engagement position. That is, the brake mechanism 30 is configured in the same manner as a well-known wet multi-plate brake that brakes the friction plate 30 with the friction plate 30 sandwiched between the brake plates 31.

  FIG. 6 shows an example of the relationship between the braking force generated by the brake mechanism 30 for the sun gear S and the output shaft 3c and the input torque. As described above, the brake mechanism 30 is configured in the same manner as a well-known wet multi-plate brake. Therefore, the frictional force between the friction plate 30 and the braking plate 31 increases as the thrust F generated by the torque cam mechanism 20 increases. Therefore, as shown in FIG. 6, in this modification, when the input torque becomes equal to or higher than the torque T1 and the engagement member 30 starts to move from the release position, the braking force increases as the input torque increases.

  In this modification, since the brake mechanism 30 is provided between the engagement member 10 and the case 5, the braking force acting on the engagement member 10 can be gradually changed. Then, the friction plate 30 and the brake plate 31 can be engaged with each other while causing slippage. Therefore, the rotation speed of the engaging member 10 can be gradually increased or decreased. This also prevents the engaging member 10 from being suddenly braked or suddenly starting to rotate. The brake mechanism 30 applied to this modification is not limited to a wet multi-plate type, and may be a dry multi-plate type.

This invention is not limited to each form mentioned above, It can implement with a various form. The differential mechanism provided in the drive device of the present invention is not limited to the planetary gear mechanism. For example, a planetary roller mechanism in which a roller is provided instead of the pinion gear may be provided as a differential mechanism . A return spring provided between the to case and the engaging member is not limited to the coil spring, it may be a plate spring.

  The torque cam mechanism is not limited to the one in which balls are provided between the cam plates. A roller may be provided instead of the ball. Further, as shown in FIG. 7, cam plates 21 c and 22 c and cam grooves 21 d and 22 d are provided in the cam plates 21 and 22, and the cam peaks 21 c and 22 c of one cam plate are cam grooves 21 d of the other cam plate. , 22d may be provided with these cam plates 21, 22. In the torque cam mechanism 20, when a torque difference occurs, the cam peaks 21 c and 22 c mesh with each other as shown by a broken line in FIG. 7, so that a thrust F for generating the cam plates 21 and 22 in the axial direction can be generated. it can.

The figure which shows the principal part of the drive device which concerns on one form of this invention. The figure which looked at the torque cam mechanism from the arrow II direction of FIG. The figure which shows an example of a torque cam mechanism when a torque difference arises between cam plates. The figure which shows an example of the relationship between input torque and the position of an engaging member. The figure which shows the modification of the drive device of this invention. The figure which shows an example of the relationship between the braking force which a brake mechanism generate | occur | produces, and input torque. The figure which shows the other example of the torque cam mechanism used for the drive device of this invention.

Explanation of symbols

1 Drive device 3 Motor generator (electric motor)
3c Output shaft 5 Case (engagement target)
7 Planetary gear unit (differential mechanism)
8 Output member 10 Engaging member 20 Torque cam mechanism 30 Brake mechanism (clutch means)
S Sun gear (first rotating element)
R ring gear (third rotating element)
C carrier (second rotating element)
CL axis

Claims (4)

In a drive device for a hybrid vehicle, comprising: a differential mechanism having a plurality of rotational elements that are mutually differential; and an electric motor having an output shaft connected to a predetermined rotational element of the differential mechanism.
An engagement member that is provided on the output shaft and is movable in an axial direction between an engagement position that contacts and engages with a predetermined engagement object and a release position that is separated from the predetermined engagement object; A torque difference that is provided in a power transmission path between a predetermined rotating element and the output shaft, and that is a difference between the torque of the output shaft and the torque of the predetermined rotating element is set to the engagement position. A torque cam mechanism that converts to a thrust to drive to the side ,
The drive device for a hybrid vehicle, wherein the predetermined engagement target is a case of the drive device fixed to the vehicle. The differential mechanism has a first rotating element, a second rotating element, and a third rotating element as the predetermined rotating elements as the plurality of rotating elements, and the power of the internal combustion engine is transmitted to the second rotating elements. And an output member is connected to the third rotating element,
2. The drive device for a hybrid vehicle according to claim 1 , wherein the torque cam mechanism generates a thrust for moving the engagement member to the engagement position when the torque difference is equal to or greater than a predetermined value set in advance. The drive device for a hybrid vehicle according to claim 1 , further comprising a biasing unit that biases the engagement member toward the release position. The larger the thrust that is interposed between the engagement member and the predetermined engagement target and drives the engagement member to the engagement position side, the greater the gap between the engagement member and the predetermined engagement target. The drive device for a hybrid vehicle according to any one of claims 1 to 3 , further comprising clutch means for increasing a generated frictional force.

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