JP2010203542A - Double clutch automatic transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a double clutch automatic transmission of a single shaft type small in radial body size, suitable for a FR vehicle and improving fuel economy. <P>SOLUTION: The double clutch automatic transmission 1 includes an input shaft 2, a first clutch CL1 disengageably transmitting rotation of the input shaft 2 to an input element of a transmission mechanism 3, and a second clutch CL2 disengageably transmitting the rotation of the input shaft 2 to the input element via an input planetary gear P1. The transmission mechanism 3 includes plural stages of transmission planetary gears P2-P4 arranged on the same axis with the input planetary gear P1 and having fixed elements, input elements and output elements. The input element of the planetary gear P2 at the first stage works as the input element of the transmission mechanism 3, and the output element of the planetary gear P4 at the final stage is connected to an output shaft 4. Synchro clutches SL2-SL4 are arranged on the same axis for selectively connecting the input element and the output element of the transmission planetary gear at a former stage to the input element of the transmission planetary gear at a latter stage. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a double clutch automatic transmission having two clutches, and more particularly to a double clutch automatic transmission configured by combining planetary gears.

  2. Description of the Related Art In recent years, a double clutch automatic transmission that can eliminate torque interruption during shift changes has attracted attention. As an example of this type of transmission, there is a twin clutch transmission disclosed in Patent Document 1. The transmission of Patent Document 1 is provided with two input shafts that are provided inside and outside the coaxial axis and are rotatable with each other, a countershaft provided in parallel with both input shafts, and both the input shaft and the countershaft. A plurality of gear sets that selectively realize each gear ratio, and two clutches that selectively input engine rotation to both input shafts. This transmission has a so-called two-axis type structure in which both input shafts and a counter shaft are arranged in parallel.

  In the double-clutch automatic transmission including the example of Patent Document 1, a two-axis type or a three-axis type in which a plurality of rotating shafts are arranged in parallel is the mainstream, and the circumference of the transmission is large, and the total length in the axial direction is relatively long. It is getting shorter. For this reason, it has become a preferable structure for the FF vehicle (front engine / front drive vehicle) in which the axes of the engine and the transmission are aligned and placed in the vehicle width direction.

  On the other hand, in addition to a structure in which a plurality of gear sets are arranged on each parallel rotating shaft, a structure in which planetary gears are combined is widely used in transmissions. In a standard planetary gear, the center sun gear, the peripheral ring gear, and the carrier holding the pinion gear meshing with both gears are either input elements, output elements, or fixed elements, and the transmission path is variable. A plurality of shift stages are realized by switching to. In recent years, various planetary gears that have been combined or modified have been put into practical use in response to the demand for an increase in the number of shift stages. Switching of the transmission path of the planetary gear is generally performed by a clutch and a brake driven by hydraulic pressure, and an automatic transmission is generally used.

JP 2006-71703 A

  By the way, the double-shaft type or the three-axis type double clutch automatic transmission is not preferable for an FR vehicle (front engine / rear drive vehicle) in which the transmission is vertically arranged in the vehicle length direction. This is because, in the FR vehicle, rotational driving force is transmitted from the front side to the rear side of the lower part of the vehicle, so that the inconvenience of narrowing the feet of the seat occurs if the waist of the transmission is large. On the other hand, in the FR vehicle, the restriction on the total length in the axial direction of the transmission was not severe. Therefore, it is important for FR vehicles to develop a transmission with a small waistline even if the overall length increases slightly.

  The present invention has been made in view of the above background, and an object of the present invention is to provide a double-clutch automatic transmission that is a single-shaft type, has a small waistline, is suitable for an FR vehicle, and further has improved fuel efficiency.

  An invention of a double-clutch automatic transmission according to claim 1 for solving the above-mentioned problems is provided with an input shaft, a first clutch that removably transmits rotation of the input shaft to an input element of the transmission mechanism, and the input shaft. A double-clutch automatic transmission comprising a second clutch that removably transmits rotation to the input element via an input planetary gear, wherein the transmission mechanism includes a plurality of stages arranged on the same axis as the input planetary gear. The transmission planetary gear of each stage has a fixed element fixed to the housing, an input element, and an output element that decelerates and outputs the rotation of the input element, and the input element of the first-stage transmission planetary gear Is used as an input element of the speed change mechanism, and an output element of the final speed change planetary gear is connected to the output shaft of the double clutch automatic transmission, The input elements and output elements, characterized in that the synchro clutch for selectively connecting the input element of the subsequent transmission planetary gear arranged on the same axis.

  According to a second aspect of the present invention, in the first aspect, the switching of the synchro clutch is performed by an actuator driven by an electric motor.

  According to a third aspect of the present invention, in the first or second aspect, the input planetary gear is directly coupled to the sun gear fixed to the housing, the input shaft, and the input element of the speed change mechanism and the first clutch. A single pinion planetary gear having a carrier to be engaged / disengaged, an input element of the transmission mechanism and a ring gear to be engaged / disengaged by the second clutch, wherein each of the transmission planetary gears is a single pinion planetary gear; The carrier is the fixed element, the sun gear is the input element, the ring gear is the output element, and the transmission planetary gears other than the final stage are the ring gear is the fixed element and the sun gear is the input element. The carrier is the output element.

  According to the first aspect of the invention configured as described above, the first and second clutches, the input planetary gear, the speed change mechanism including the plurality of speed change planetary gears, and the synchro clutch are all arranged on the same axis. Can be arranged. Therefore, the structure of the transmission can be a single-shaft type, the waistline can be reduced, and a double clutch automatic transmission suitable for an FR vehicle can be obtained. According to the second aspect of the present invention, the gear position can be changed by switching the synchro clutch by driving the electric motor. Therefore, compared with the hydraulic drive, the shift speed can be switched quickly, and the fuel efficiency can be improved.

  According to the invention of claim 3, a single pinion planetary gear having a simple structure is used for all of the input planetary gear and the multiple-speed planetary gears, and only the output path is switched without switching the fixed element and the input element. Each gear stage is realized. Therefore, the configuration and control of the transmission can be simplified. Furthermore, a brake element and a clutch element for switching between the fixed element and the input element are unnecessary, and the effect of reducing the waistline becomes more remarkable.

It is a skeleton figure of the double clutch automatic transmission of the embodiment of the present invention. It is a speed diagram of the double clutch automatic transmission of FIG. 2 is an operation table of the double clutch automatic transmission of FIG. 1.

  The form for implementing this invention is demonstrated with reference to FIGS. 1-3. FIG. 1 is a skeleton diagram of a double clutch automatic transmission 1 according to an embodiment of the present invention. The double-clutch automatic transmission 1 according to the embodiment is for a vehicle and has a shift stage of 6 forward speeds and 1 reverse speed. The automatic transmission 1 includes an input shaft 2, a first clutch CL 1, a second clutch CL 2, an input planetary gear P 1, three sets of transmission planetary gears P 2 to P 4 that form a transmission mechanism 3, three sets of synchro clutches SC 2 to SC 4, and an output shaft 4. Etc.

  The input shaft 2 is a member that transmits the rotation of the engine into the automatic transmission 1. The input planetary gear P1 is a single pinion type, and includes a sun gear S1 fixed to the housing 8 as a fixed element, a carrier C1 directly connected to the input shaft 2 as an input element, and a ring gear R1 as an output element. . As is well known, the carrier C1 is a member that rotates while holding a plurality of pinion gears that mesh with the sun gear S1 and the ring gear R1.

  As shown in FIG. 1, the carrier C1 of the input planetary gear P1 is engaged with and disengaged from the input element of the rear transmission mechanism 3 by the first clutch CL1, and the ring gear R1 is also connected to the input element of the rear transmission mechanism 3 by the second clutch CL2. Being engaged and disengaged. That is, one of the carrier C1 and the ring gear R1 is selectively connected to the subsequent stage. The first clutch CL1 and the second clutch CL2 are wet multi-plate clutches and are disposed on the same axis adjacent to the input planetary gear P1. The structures of the first clutch CL1 and the second clutch CL2 are not limited to the wet multi-plate type. Further, a torque converter that is frequently used in conventional automatic transmissions is unnecessary.

  The transmission mechanism 3 includes three sets of single-pinion type transmission planetary gears P2 to P4 arranged on the same axis as the input planetary gear P1. As shown in FIG. 1, in the first-stage first transmission planetary gear P2 arranged on the input side, the ring gear R2 is a fixed element and fixed to the housing 8, the sun gear S2 is an input element, and the carrier C2 is an output element. It is said that. The sun gear S2 is an input element of the entire speed change mechanism 3, and is connected to a common output side of the first clutch CL1 and the second clutch CL2. A synchro clutch SC2 having a sleeve SL2 is provided adjacent to the first transmission planetary gear P2 and on the same axis. The sleeve SL2 is spline-coupled with a sun gear S3 of a second transmission planetary gear P3, which will be described later, and rotates integrally, and is moved in both axial directions by an actuator driven by an electric motor. When the sleeve SL2 moves in one axial direction, the sleeve SL2 is connected to the sun gear S2. When the sleeve SL2 moves in the other axial direction, the sleeve SL2 is connected to the carrier C2, and transmits one of the rotations to the sun gear S3 at the subsequent stage.

  Similarly, in the second speed planetary gear P3 of the next stage, the ring gear R3 is a fixed element and fixed to the housing 8, the sun gear S3 is an input element and is connected to the sleeve SL2 of the preceding synchro clutch SC2, and the carrier C3 is It is an output element. A synchro clutch SC3 having a sleeve SL3 is provided adjacent to the second speed change planetary gear P3 and on the same axis. The sleeve SL3 is spline-coupled with a sun gear S3 of a final transmission planetary gear P4, which will be described later, and rotates integrally, and is moved in both axial directions by an actuator driven by an electric motor. When the sleeve SL3 moves in one axial direction, the sleeve SL3 is connected to the sun gear S3. When the sleeve SL3 moves in the other axial direction, the sleeve SL3 is connected to the carrier C3 and transmits one of the rotations to the sun gear S4 in the subsequent stage.

  In the final stage final transmission planetary gear P4, the carrier C4 is a fixed element and is fixed to the housing 8, the sun gear S4 is an input element and is connected to the sleeve SL3 of the preceding synchro clutch SC3, and the ring gear R4 is an output element. ing. A synchro clutch SC4 having a sleeve SL4 is provided on the same axis line adjacent to the final transmission planetary gear P4. The sleeve SL4 is splined to the output shaft 4 to rotate integrally, and is configured to be moved in both axial directions by an actuator driven by an electric motor. When the sleeve SL4 moves in one axial direction, the sleeve SL4 is connected to the sun gear S4. When the sleeve SL4 moves in the other axial direction, it is connected to the ring gear R4 to transmit any one rotation to the output shaft 4. The final transmission planetary gear P4 has a role of forming a reverse speed by rotating and inputting the rotation input to the sun gear S4 by reverse rotation with the ring gear R4. The output shaft 4 is configured to transmit rotation to the wheels via a differential device or the like.

  Next, the operation of realizing each gear stage in the double clutch automatic transmission 1 of the embodiment configured as described above will be described with reference to FIGS. The white circles in the speed diagram of FIG. 2 indicate positions where the respective shift speeds (1st to 6th, Rev) are realized. Also, in the operation table of FIG. 3, the first clutch CL1 and second clutch CL2 columns indicate engagement with circles, and the synchro clutch SC2 to SC4 columns indicate elements to be connected.

  First, at the first speed, as shown in the first stage (1st) of the operation table of FIG. 3, the first clutch C1 is selectively engaged with the input planetary gear P1, and the sync clutch SC2 is engaged with the first transmission planetary gear P2. Connects the carrier C2 to the rear stage, the synchro clutch SC3 connects the carrier C3 to the rear stage at the second speed planetary gear P3, and the synchro clutch SC4 operates to connect the sun gear S4 to the output shaft 4 at the final speed planetary gear P4. Then, as shown in FIG. 2, the input planetary gear P1 outputs the rotation of the input shaft 2 and the carrier C1 at a constant speed, and the fifth speed (5th) rotation realized by the sun gear S2 of the first transmission planetary gear P2 is output. Decelerated at the reduction ratio r2 and output from the carrier C2 as the third speed (3rd), and the rotation of the third speed (3rd) of the sun gear S3 of the second transmission planetary gear P3 is further decelerated at the reduction ratio r3 and the first at the carrier C3. The speed (1st) is realized and output, and in the final transmission planetary gear P4, the first speed (1st) rotation of the sun gear S4 is output to the output shaft 4 as it is.

  At the sixth speed, as shown in the sixth stage (6th) of the operation table of FIG. 3, the second clutch C2 is selectively engaged by the input planetary gear P1, and the synchro clutch SC2 is engaged by the first transmission planetary gear P2. The sun gear S2 is connected to the rear stage, the synchro clutch SC3 is connected to the rear gear at the second speed planetary gear P3, and the synchro clutch SC4 is operated to connect the sun gear S4 to the output shaft 4 at the final speed planetary gear P4. Then, the input planetary gear P1 outputs the rotation of the ring gear R1 accelerated at the speed increase ratio r1, and the sixth gear (6th) is realized by the sun gear S2 of the first transmission planetary gear P2. Thereafter, the sun gear S3 is moved from the sun gear S3 to the sun gear S4. Then, the output shaft 4 is output without being decelerated.

  The second speed is realized by the carrier C3 of the second transmission planetary gear P3, the third speed and the fourth speed are realized by the carrier C2 of the first transmission planetary gear P2, and the fifth speed is the first transmission planetary gear. It is realized by the sun gear S2 of P2, and each is output to the output shaft 4.

  Further, at the reverse speed, the synchro clutch SC4 operates so as to connect the ring gear R4 to the output shaft 4 at the final transmission planetary gear P4. Then, the rotation of the ring gear R4 obtained by reversing and reducing the rotation of the sun gear S4 with the reduction ratio r4 is output to the output shaft 4. FIG. 2 shows an example in which the reverse speed of the first speed (1st) is reversed and the reverse speed (Rev) is realized. However, the present invention is not limited to this. In principle, the first speed (1st) to the sixth speed are shown. (6th) can be reversely decelerated at a reduction ratio r4 to obtain the sixth reverse speed, and a plurality of reverse speeds may be used as appropriate.

  According to the double clutch automatic transmission 1 of the present embodiment, the first clutch CL1 and the second clutch CL2, the input planetary gear P1, the transmission planetary gears P2 to P4, and the synchro clutches SC2 to SC4 are all arranged on the same axis. be able to. Therefore, the structure of the transmission can be a single-shaft type, and the waistline can be reduced. In addition, since each of the sync clutches SC2 to SC4 is switched by driving the electric motor, the shift speed can be switched more quickly than in the hydraulic drive, and the fuel consumption can be improved.

  Further, the input planetary gear P1 and the transmission planetary gears P2 to P4 are single-pinion planetary gears with a simple structure, and the fixed element and the input element are not switched, and only the output path is switched. Furthermore, a torque converter can be eliminated. Therefore, the configuration and control of the automatic transmission 1 are simplified, and the downsizing of the waistline becomes even more remarkable.

  The illustrated gear ratio (speed increase ratio r1, speed reduction ratio r2 to r4) is a schematic example, and can be applied with appropriate changes. Further, the combination of the fixed element, the input element, and the output element can be freely changed. For example, if each element of the input planetary gear P1 is set in the same manner as the first transmission planetary gear P2 for deceleration, a transmission with a gear ratio of 1 can be achieved even at the highest speed.

  Furthermore, the quantity of the transmission planetary gears P2 and P3 can be increased or decreased. For example, if the second transmission planetary gear P3 is omitted, a forward four-speed transmission can be obtained. Further, if a speed-change planetary gear is added between the second speed-change planetary gear P3 and the final speed-change planetary gear P4, the number of forward stages (addition number × 2) can be increased.

1: Double clutch automatic transmission 2: Input shaft 3: Transmission mechanism 4: Output shaft 8: Housing CL1: First clutch CL2: Second clutch P1: Input planetary gear P2: First transmission planetary gear P3: Second transmission planetary gear P4: Final transmission planetary gears S1 to S4: Sun gear C1 to C4: Carrier R1 to R4: Ring gears SC2 to SC4: Synchro clutch SL2 to SL4: Sleeve r1: Speed increase ratio r2 to r4: Reduction ratio

Claims (3)

A first clutch that removably transmits rotation of the input shaft to an input element of the speed change mechanism; and a second clutch that removably transmits rotation of the input shaft to the input element via an input planetary gear. Double clutch automatic transmission with clutch,
The speed change mechanism includes a plurality of speed change planetary gears arranged on the same axis as the input planetary gear,
The transmission planetary gear at each stage has a fixed element fixed to the housing, an input element, and an output element that decelerates and outputs the rotation of the input element, and the input element of the first-stage transmission planetary gear is input to the transmission mechanism. As an element, the output element of the final stage planetary gear is connected to the output shaft of the double clutch automatic transmission,
2. A double clutch automatic transmission characterized in that a synchro clutch for selectively connecting an input element and an output element of a front transmission planetary gear to an input element of a rear transmission planetary gear is disposed on the same axis.   2. The double clutch automatic transmission according to claim 1, wherein switching of the synchro clutch is performed by an actuator driven by an electric motor. 3. The double clutch automatic transmission according to claim 1, wherein the input planetary gear is directly connected to the sun gear fixed to the housing, the input shaft, and the input element of the speed change mechanism and the first clutch. A single pinion planetary gear having a carrier to be engaged and disengaged, a ring gear to be engaged and disengaged by an input element of the speed change mechanism and the second clutch,
Each of the transmission planetary gears is a single pinion planetary gear,
In the final stage transmission planetary gear, a carrier is the fixed element, a sun gear is the input element, and a ring gear is the output element.
A double-clutch automatic transmission characterized in that, in the transmission planetary gear other than the final stage, a ring gear is the fixed element, a sun gear is the input element, and a carrier is the output element.

Images