JP4792811B2 - Automatic transmission - Google Patents

Description

  The present invention relates to an automatic transmission.

  Conventionally, an automatic transmission using two planetary gear trains is known (see Patent Document 1). This type of automatic transmission is configured to change speed by changing the power transmission path by selectively switching rotation / non-rotation of some of the plurality of rotating elements using a clutch, a brake, or the like. ing.

On the other hand, Patent Documents 2 and 3 describe driving devices that drive a vehicle by combining engine rotation and motor rotation using a single planetary gear train.
Japanese Patent Laid-Open No. 11-351369 JP-A-5-319110 Japanese Patent Laid-Open No. 8-197962

  However, the above prior art has no idea of using an electric motor to supplement the gear position. In other words, an automatic transmission using two planetary gear trains as disclosed in Patent Document 1 can only realize a gear stage having a gear ratio mechanically determined by the gear ratio of the gear train. For example, when two general planetary gear trains are used, it is determined to be a four-speed shift from the first speed to the fourth speed, and the shift speed cannot be increased easily.

  On the other hand, so-called hybrid drive technology represented by Patent Documents 2 and 3 simply uses a planetary gear train to add rotation of the motor to the rotation of the engine, and enables mechanical gear shifting. Is not included, and there was no idea of supplementing the gear position.

  The present invention has been made to solve the above-described problems of the prior art, and combines a mechanical automatic transmission mechanism and an electric motor to increase a gear ratio that can be realized by an automatic transmission with a simple configuration. In particular, a wide range of gear ratio to the high geared side is to be achieved.

  In order to achieve the above object, an automatic transmission according to the present invention includes a speed change mechanism including at least two sets of connected planetary gear trains, and a rotation control element that switches a power transmission path of the speed change mechanism. An automatic transmission that realizes a mechanical shift of a stage, which is in a non-driven state at the time of selection of each shift stage that is mechanically realized by the transmission mechanism and the rotation control element, and is included in the planetary gear train An electric motor for rotating a part of the rotation elements, wherein the rotation control element is activated when the highest gear stage mechanically realized by the transmission mechanism and the rotation control element is selected, Including a brake that fastens the rotating element and the transmission case, the brake is inactivated, and the rotating element is rotated with the electric motor in a driving state, thereby changing the speed higher than the maximum gear. Characterized in that to achieve a ratio.

  In addition, an automatic transmission according to the present invention includes a transmission mechanism including at least two sets of connected planetary gear trains, and a rotation control element that switches a power transmission path of the transmission mechanism. An automatic transmission that achieves a gradual shift, and is in a non-driven state at the time of selection of each shift stage that is mechanically realized by the transmission mechanism and the rotation control element, and includes a part of the planetary gear train A motor that rotates the rotating element; and the rotation control element is activated when the fourth speed stage is selected, and is operated when the fourth speed stage is selected. A clutch that engages between predetermined rotating elements included in the planetary gear train, wherein the brake is deactivated, the clutch is activated, and the electric motor is driven. Rotating element By rolling, characterized in that than fourth speed to achieve high-speed side gear ratio.

  According to this, it is possible to increase the speed ratio that can be realized by the automatic transmission with a simple configuration, and in particular, it is possible to achieve a wide range of the speed ratio toward the high geared side.

  Here, when the electric motor rotates the rotating element, a speed ratio on the higher speed side than the highest gear stage that can be mechanically realized by the two sets of planetary gear trains is realized. Thereby, the wide range of the gear ratio to the high geared side can be achieved.

In addition, the rotation control element is partly rotated by the electric motor when it is activated when selecting the highest speed stage mechanically realized by the speed change mechanism and the rotation control element or when selecting the fourth speed stage. By having a brake for fastening the rotating element and the transmission case, a mechanical gear shift can be realized when the battery voltage drops or the electric motor fails.

  The electric motor realizes the high speed side gear ratio in a step-shift manner. Particularly, in the case of a configuration in which a four-speed shift is realized by two sets of planetary gear trains, a gear ratio corresponding to the fifth speed and the sixth speed is further realized by operating the electric motor. Thereby, the engine speed at the time of high speed can be lowered, and the fuel consumption can be improved and the noise can be reduced by adding a simple configuration.

  The motor is controlled so that the rotational speed of the rotating element is changed so that the high-speed gear ratio changes steplessly. As a result, CVT-like settings can be made, and fuel consumption can be further reduced.

  The number of revolutions of the rotating element is changed by controlling the electric motor so that the speed ratio on the higher speed side than the highest gear becomes a value corresponding to the traveling state of the vehicle. Thereby, the drive according to a driving | running | working state can be performed and driving | running | working property can be improved.

According to the present invention, a mechanical automatic transmission mechanism and an electric motor are combined to increase the transmission ratio that can be realized by the automatic transmission with a simple configuration, and in particular, to achieve a wide range of transmission ratio to the high geared side. In addition, a mechanical shift can be realized when the battery voltage is reduced or the motor is broken by the brake that fastens a part of the rotating elements rotated by the motor and the transmission case.

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the components and the like described in this embodiment are merely examples, and are not intended to limit the scope of the present invention only to them.

(First embodiment)
First, the mechanical configuration of the automatic transmission 10 according to the embodiment of the present invention will be described with reference to FIG.

  The automatic transmission 10 includes, as main components, a torque converter 20, a speed change mechanism 30 driven by the output of the torque converter 20, and a plurality of rotation control elements such as a clutch and a brake for switching a power transmission path of the speed change mechanism 30. 41-45 and the one-way clutch 46, and the motor 50, these can obtain 1-6 speed in forward ranges, such as D, S, and L ranges, and the reverse speed in R range.

  The torque converter 20 includes a pump 22 connected to the engine output shaft 1 and fixed in the case 21. Further, a turbine 23 is provided at a position facing the pump 22 and is driven by the pump 22 via hydraulic oil. Furthermore, it has the stator 25 which is provided between the pump 22 and the turbine 23, is fixed to the transmission case 11 via the one-way clutch 24, and performs a torque increasing action. A lock-up clutch 26 that directly connects the engine output shaft 1 and the turbine 23 via the case 21 is provided between the case 21 of the torque converter 20 and the turbine 23. The rotation of the turbine 23 is output to the transmission mechanism 30 side via the turbine shaft 27.

  Here, an oil pump 12 that is driven by the engine output shaft 1 via a case 21 of the torque converter 20 is disposed on the opposite side of the engine across the torque converter 20.

  On the other hand, the transmission mechanism 30 includes two sets of planetary gear trains 31 and 32. The planetary gear train has sun gears 31a and 32a, respectively, and has a plurality of pinion gears 31b and 32b engaged with the sun gears 31a and 32a. Further, it has planetary carriers 31c and 32c for supporting these pinion gears 31b and 32b, and ring gears 31d and 32d engaged with the pinion gears 31b and 32b.

  A forward clutch (forward CL) 41 is disposed between the turbine shaft 27 and the sun gear 31 a of the planetary gear train 31. Similarly, a reverse clutch (reverse CL) 43 is disposed between the turbine shaft 27 and the sun gear 32 a of the planetary gear train 32. A 3-4 clutch (3-4 CL) 42 is disposed between the turbine shaft 27 and the planetary carrier 32 c of the planetary gear train 32. Further, a band brake (2-4BR) 44 for fixing the sun gear 32a of the planetary gear train 32 is disposed.

  Further, the sun gear 32 a of the planetary gear train 32 is further connected to a motor 50, and the rotation speed is controlled by the motor 50.

  The ring gear 31d of the planetary gear train 31 and the planetary carrier 32c of the planetary gear train 32 are connected, and a low reverse brake (L & R BR) 45 and a one-way clutch (OWC) 46 are parallel between these and the transmission case 11. The planetary carrier 31c of the planetary gear train 31 and the ring gear 32d of the planetary gear train 32 are connected to each other, and the output gear 13 is connected to them. The rotation of the output gear 13 is transmitted to the left and right axles 6 and 7 via the transmission gears 2, 3, 4 and the differential mechanism 5.

  As described above, the automatic transmission 10 includes at least two sets of planetary gear trains 31 and 32 connected to each other, and realizes a multi-stage mechanical speed change by switching the power transmission path. Furthermore, the electric motor 50 which controls the rotation speed of the one part rotation element 32a contained in the planetary gear trains 31 and 32 is further provided. Using this electric motor 50, the rotational element 32a is rotationally controlled in accordance with the input rotational speed to the automatic transmission 10, thereby expanding the degree of freedom to a realizable gear ratio.

  FIG. 2 is a perspective view showing the configuration of the automatic transmission according to the present embodiment. The arrow shown here indicates a rotation transmission path when the motor is driven in a high speed region of 4th speed or higher.

  When the speed is higher than the fourth speed, the 3-4 clutch 42 is engaged and the motor 50 is driven. Other rotation control elements do not operate. The motor 50 rotates the sun gear 32a in the opposite direction (arrow direction in the figure) to the input rotation from the engine. The rotational speed is proportional to the engine rotational speed.

  The rotation input from the torque converter 20 rotates the planetary carrier 32c around the sun gear 32a through the 3-4 clutch 42 from the turbine shaft 27. At this time, the sun gear 32 a is rotated in the direction of the arrow by the motor 50. Accordingly, the coupled ring gear 31d and pinion gear 32b rotate in the direction of the arrow at a higher rotational speed than when the sun gear 32a is fixed by the brake 44 (at the fourth speed). At this time, the ring gear 32d that meshes with the pinion gear 32b rotates in the direction of the arrow.

  Along with this, the planetary carrier 31c and the output gear 13 rotate in the arrow direction around the sun gear 31a. As a result, the transmission gears 2 to 4 rotate in the direction of the arrow to rotate the axle. The number of rotations of the axle increases as the number of rotations of the motor 50 increases.

  Here, the relationship between the operation states of the rotation control elements 41 to 45 such as the clutches and brakes, the one-way clutch 46 and the motor 50 and the gear stage is shown in FIG. In this figure, ○ indicates the case where the rotation control element stops the rotation element or the case where the motor is driven.

  As shown in FIG. 3, at the first speed, the forward clutch 41 and the one-way clutch 46 are engaged. The low and reverse brake 45 is engaged in the L range. In this state, the rotation of the turbine shaft 27 is transmitted to the sun gear 31a by the forward clutch 41. When the sun gear 31a rotates, the pinion gear 31b also rotates. Along with this, the ring gear 31d also tries to rotate, but the ring gear 31d is not rotated because it is fixed by the one-way clutch 46 or the low and reverse brake 45. Accordingly, the pinion gear 31b rotates in the fixed ring gear 31d, and accordingly, the planetary carrier 31c rotates. As a result, the output gear 13 connected to the planetary carrier 31c rotates around the sun gear 31a. As a result, the transmission gears 2 to 4 rotate to rotate the axle.

  In the second speed, the forward clutch 41 and the band brake 44 are engaged, and the other rotation control elements are free. In this state, the rotation of the turbine shaft 27 is transmitted to the sun gear 31a by the forward clutch 41. When the sun gear 31a rotates, the pinion gear 31b also rotates. Along with this, the ring gear 31d also rotates, and the planetary carrier 32c connected to the ring gear 31d also rotates. At this time, since the sun gear 32a is fixed by the band brake 44, the ring gear 32d rotates, and accordingly, the planetary carrier 31c rotates. As a result, the output gear 13 connected to the planetary carrier 31c rotates around the sun gear 31a. As a result, the transmission gears 2 to 4 rotate to rotate the axle.

  At the third speed, the forward clutch 41 and the 3-4 clutch 42 are engaged, and the other rotation control elements are free. In this state, the rotation of the turbine shaft 27 is transmitted to the sun gear 31a by the forward clutch 41. The rotation of the turbine shaft 27 is also transmitted to the planetary carrier 32c via the 3-4 clutch 42, and the planetary carrier 32c rotates around the turbine shaft 27. As a result, the ring gear 31d connected to the planetary carrier 32c also rotates. The pinion gear 31b sandwiched between the rotating ring gear 31d and the sun gear 31a rotates the planetary carrier 31c around the sun gear 31a. As a result, the output gear 13 connected to the planetary carrier 31c rotates around the sun gear 31a. As a result, the transmission gears 2 to 4 rotate to rotate the axle.

  In the 4th speed or high speed range, as described with reference to FIG. 2, the 3-4 clutch 42 is engaged, and the band brake 44 is engaged (4th speed) or the motor 50 is driven (5th and 6th speeds).

  On the other hand, in reverse, the reverse clutch 43 and the low and reverse brake 45 are engaged, and the other rotation control elements are set free. In this state, the rotation of the turbine shaft 27 is transmitted to the sun gear 32 a by the reverse clutch 43. Along with this, the pinion gear 32b rotates and the ring gear 32d also rotates. For this reason, the planetary carrier 31c connected to the ring gear 32d also rotates around the sun gear 31a. As a result, the output gear 13 connected to the planetary carrier 31c rotates around the sun gear 31a. As a result, the transmission gears 2 to 4 rotate to rotate the axle. In this case, the output rotation is in the opposite direction to the input rotation.

  Next, the rotation speed of the motor 50 will be described with reference to FIG. FIG. 4 is a velocity diagram, and shows the relationship between the rotational speeds of the respective gears included in the two sets of planetary gear trains 31 and 32 shown in FIGS. 1 and 2. The four vertical axes 401 to 404 indicate the sun gear 31a, 402 the planetary carrier 31c (ring gear 32d), 403 the ring gear 31d (planetary carrier 32c), and 404 the sun gear 32a in order from the right. The interval between the vertical axes indicates the reciprocal of the ratio of the number of gear teeth.

  That is, when the number of teeth S1 of the sun gear 31a is the number of teeth R1 of the ring gear 31d = 1: α1, the distance L1: 401 between the distances 401 and 402 is L2 = α1: 1. Further, when the number of teeth S1 of the sun gear 32a is the number of teeth R1 = 1: α2 of the ring gear 32d, the interval L2 between 402 and 403 is L3 = 1: α2 between 403 and 404.

  Thus, in this graph, the vertical axis indicates the rotation speed of each gear. Particularly, in the case of the third speed or higher, the 3-4 clutch 42 is engaged, so that the input rotational speed Ni = the rotational speed of the ring gear 31d. In other words, the straight lines 411 to 414 indicating the rotation speeds of the respective gears of the third and higher gear stages all pass through the point 420 where 403 becomes NI. On the other hand, the output rotational speed indicates the rotational speed 402 of the ring gear 32d.

  In general, in the third speed, since the input rotation speed and the output rotation speed are the same (the reduction ratio is 1), a horizontal straight line 411 passing through 420 is obtained. On the other hand, in the case of the fourth speed, since the sun gear 32a is stopped, the straight line 412 passes through the point 421 where 404 is zero. The intersection of the straight line 412 and the straight line 402 represents the output speed No. 4 of the fourth speed. If the reduction ratio of the fourth speed is 0.725, the relationship is Ni: No4 = 0.725: 1. Accordingly, the number of teeth of each gear included in the planetary gear train 32 is determined from the geometric relationship so that the interval between 404 and 403: the interval between 404 and 403 = α2: α2 + 1 = 0.725: 1. To do.

  At this time, if the fifth speed and the sixth speed are realized by the motor 50 in a step-shift manner, the fifth speed is represented by a straight line 413, and the sixth speed is represented by a straight line 414. Accordingly, the rotational speed of the sun gear 32a at the 5th speed and 6th speed, that is, the motor speeds Nm5 and Nm6, respectively, are i5 for the 5th speed and i6 for the 6th speed. This is expressed as follows.

Nm5 = (α2 / i5-α2-1) · Ni
Nm6 = (α2 / i6-α2-1) · Ni

  In this way, when the electric motor rotates the sun gear 32a as a rotating element, the gear ratio on the higher speed side (5th speed, 6th speed) than the maximum speed stage (here 4th speed) that can be mechanically realized by the planetary gear train. Is realized. That is, a four-speed shift is realized by the two sets of planetary gear trains 31 and 32 and the electric motor 50 is operated to further realize a gear ratio corresponding to the fifth speed and the sixth speed in a step-shift manner.

  Note that the rotational speed of the sun gear 32a may be controlled using the electric motor 50 so that the speed ratio on the higher speed side than the maximum gear stage changes steplessly. Further, the rotational speed of the sun gear 32a may be controlled using the electric motor 50 so that the speed ratio on the higher speed side than the maximum gear position becomes a value corresponding to the traveling state of the vehicle. Here, the traveling state of the vehicle refers to whether or not the vehicle is traveling uphill. That is, it is conceivable to increase the speed reduction ratio (that is, to reduce the rotation speed of the motor 50) in order to gain torque in the case of traveling uphill. It is desirable to change the number of rotations of the motor according to various traveling conditions (torque, resistance, acceleration), etc., whether it is uphill or not.

  Next, the control process of the motor 50 will be described with reference to FIG. FIG. 5 is a flowchart showing a flow of control processing of the motor 50. Specifically, a CPU (not shown) for controlling the motor 50 is provided on a control board in the vehicle, and the following processing is performed by the CPU periodically executing a specific program.

  First, in step S501, first, the vehicle speed and the throttle opening are acquired. Then, the process proceeds to step S502, and with reference to the shift map shown in FIG. 6, it is determined which gear stage should be shifted from the vehicle speed and the throttle opening.

  Further, in step S503, it is determined whether or not shifting to the 5th or 6th speed is performed. If shifting to the 5th or 6th speed is to be performed, the process proceeds to step S504, and the rotation derived using the above-described equation. The motor 50 is rotated by a number. When shifting to the fourth speed or less, or when not shifting, the process is terminated.

  Through the processing as described above, as indicated by reference numeral 701 in FIG. 7, the reduction ratio can be lowered at high speeds compared to the case of simple four-speed AT (702). Thereby, as shown by 703, the engine speed can also be lowered as compared with the case of simple 4-speed AT (704).

  Further, the rotational speed of the motor 50 may be controlled so that the engine rotational speed is not constant but stepwise. In that case, what is necessary is just to change the rotation speed of the motor 50 steplessly according to a vehicle speed and throttle opening. If the motor speed during this period is Nmh, the relationship with the target reduction ratio ih is expressed as follows.

  Nmh = (α2 / ih−α2-1) · Ni

  By driving in such a CVT manner, the speed reduction ratio can be changed as shown at 801 in FIG. 8 at a high speed, and the engine speed becomes constant as shown at 803.

  In this embodiment, the motor 50 and the band brake 44 are provided side by side, and the sun gear 32a is stopped using the band brake 44 in the second speed and the fourth speed, but only the motor 50 is provided. The sun gear 32a may be stopped by the motor 50. Further, the sun gear 32a may be stopped by the motor 50 while the motor 50 and the band brake 44 are provided, and the sun gear 32a may be stopped using the band brake 44 when the motor 50 has a problem.

  In the present embodiment, the motor 50 is provided outside the transmission mechanism 30. However, a stator is attached to the inner wall of the transmission case 11 so as to replace the band brake 44 of FIG. 1, and the rotor is connected to the sun gear 32a. good.

  As described above, according to the automatic transmission according to the present embodiment, the degree of freedom of the gear ratio that can be realized by the automatic transmission with a simple configuration can be increased. In particular, a wide range of gear ratio to the high geared side can be achieved, and as a result, the engine speed at high speed can be reduced, and by adding a simple configuration, fuel consumption can be improved and silence can be achieved. it can. Thereby, the drive according to a driving | running | working state can be performed and driving | running | working property can be improved.

  In order to achieve the highest gear position mechanically with the two sets of planetary gear trains, the rotating element is stopped. In addition, a brake for stopping the rotating element is further provided. As a result, a mechanical shift can be realized when the battery voltage drops or the electric motor fails.

It is a skeleton figure which shows the structure of the automatic transmission as embodiment of this invention. It is a perspective view which shows the structure of the automatic transmission as embodiment of this invention. It is a figure which shows control of the automatic transmission as embodiment of this invention. It is a velocity diagram which guide | leads the motor rotation speed of the automatic transmission as embodiment of this invention. It is a flowchart which shows the motor control of the automatic transmission as embodiment of this invention. It is a figure which shows the motor control of the automatic transmission as embodiment of this invention. It is a figure which shows the effect of the automatic transmission as embodiment of this invention. It is a figure which shows the effect of the modification of the automatic transmission which concerns on this invention.

1 Engine output shaft 2, 3, 4 Transmission gear 5 Differential mechanism 6, 7 Axle 10 Automatic transmission 11 Transmission case 12 Oil pump 13 Output gear 20 Torque converter 21 Case 22 Pump 23 Turbine 24 One-way clutch 25 Stator 26 Lock-up clutch 27 turbine shaft 30 speed change mechanism 31, 32 planetary gear train 31a, 32a Sangi ya <br/> 31b, 32 b pinion gear 31c, 32c planetary carrier 31d, 32d ring gear 41 forward clutch 42 3-4 clutch 43 reverse clutch 44 band brake 45 Low reverse brake 46 One-way clutch 50 Motor

Claims (6)

Comprising a transmission mechanism having at least two sets of planetary gear train coupled, a rotation control element for switching the dynamic Chikaraden our path speed change mechanism, and there in the automatic transmission to achieve the mechanical transmission of the plurality of stages And
An electric motor which is in a non-driven state at the time of selection of each shift stage mechanically realized by the transmission mechanism and the rotation control element, and rotates a part of the rotation elements included in the planetary gear train;
The rotation control element includes a brake that is activated when a maximum gear stage mechanically realized by the transmission mechanism and the rotation control element is selected and that fastens the partial rotation element and a transmission case;
An automatic transmission characterized in that a speed ratio on a higher speed side than the highest gear stage is realized by rotating the part of the rotating elements while the brake is in an inoperative state and the electric motor is in a driving state . A transmission mechanism having at least two sets of planetary gear train coupled, a rotation control element for switching the dynamic Chikaraden our path speed change mechanism, comprising a automatic transmission to achieve the mechanical transmission of the forward fourth speed Because
An electric motor which is in a non-driven state at the time of selection of each shift stage mechanically realized by the transmission mechanism and the rotation control element, and rotates a part of the rotation elements included in the planetary gear train;
The rotation control element is
A brake that is activated when the fourth speed stage is selected and that fastens the part of the rotating elements and the transmission case;
A clutch that is activated when the fourth gear stage is selected and that fastens between predetermined rotating elements included in the planetary gear train,
A speed ratio on a higher speed side than the fourth speed stage is realized by rotating the part of the rotating elements with the brake being inactivated, the clutch being operated, and the electric motor being driven. Automatic transmission to do. The motor, the automatic transmission according to the transmission ratio of the pre-Symbol high-speed side to claim 1 or 2, characterized in that to realize the step shift manner. By actuating the pre Symbol motor, an automatic transmission according to claim 2, characterized in that to realize the fifth speed and the gear ratio of the corresponding 6-speed. Gear ratio before Symbol high-speed side, so as to change steplessly, by using the electric motor, automatic according to claim 1 or 2, characterized in that to control the rotational speed of the rotating element of the part transmission. Gear ratio before Symbol high-speed side, to a value corresponding to the running state of the vehicle, using the electric motor, according to claim 1, characterized in that to control the rotational speed of the rotating element of the part automatic transmission according to any one of 5.

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