JPS632735A - Automatic transmission gear for vehicle - Google Patents

Abstract

PURPOSE:To eliminate shock due to gear change by providing an auxiliary clutch between an inpnt shaft and an output shaft whereby conditioning the auxiliary clutch to a semi-engagement while a main clutch is being maintained in an engagement when paired gears for power transmission are changed over. CONSTITUTION:An auxiliary clutch 54 is provided between an inpnt shaft 22 and an output shaft 30 so as to be connected with a main clutch in a similar manner as in series. And when the piared gear of a transmission gear 14 is changed over, the auxiliary clutch 54 is conditioned to a semi-engagement while the main clutch 12 is being maintained in an engagement by a shift control device 102. As a result, when the transmission gear 14 is shifted, a vehicle is driven by the power transmitted by way of the auxiliary clutch 54. Owing to this constitution, a delicate timing control required between the main clutch 12 and the auxiliary clutch 54 is eliminated, thereby eliminating shock due to change gear and responded revolving speed of an engine.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to an automatic transmission for a vehicle, and more particularly to a technique for preventing shift shock when switching gear pairs and facilitating shift control.

Prior Art An input shaft connected to an engine via a main clutch, an output shaft connected to a driving wheel, and multiple types of gear pairs for transmitting the power of the input shaft to the output shaft at mutually different gear ratios. and a shift member operated to select the gear pair, and by automatically operating the shift member, the power transmitted from the engine is transmitted to the drive wheels at a desired gear ratio. A type of automatic transmission device for a vehicle is known. According to such a device, since a mechanism similar to that of a conventional manual transmission is adopted, there is an advantage that even when automatic gear shifting is performed, the same economy as that of the manual transmission can be obtained.

However, when the automatic transmission automatically shifts, the amount of fuel supplied to the engine is reduced according to a predetermined operating sequence, temporarily lowering the engine's output, and at the same time, the input to the stepped transmission is reduced. After the main clutch connecting the shaft and the engine is released, the actuator changes the gear stage of the stepped transmission, and the main clutch is again engaged. For this reason, there is an inconvenience that the shift feeling is impaired during the period in which the main clutch is released, that is, during the period in which power transmission from the engine is interrupted.

In particular, in a shift in a low gear, such as an amplifier shift from the first gear to the second gear, or from the second gear to the third gear, or vice versa, a downshift. This inconvenience is significant because the difference between the drive torque of the transmission human power shaft and the drive torque of the output shaft is large.

On the other hand, for example, as described in Japanese Patent Application Laid-Open No. 58-193951, by providing a sub clutch between the engine and the output shaft in parallel with the main cod and clutch, the main clutch It has been proposed that while the clutch is released, the sub-clutch is in a semi-engaged state to transmit rotational energy of the engine to the drive wheels of the vehicle, thereby alleviating interruptions in power transmission during gear shifting.

Problems to be Solved by the Invention However, in such conventional automatic transmissions, the auxiliary clutch is arranged between the engine and the output shaft so that it is parallel to the main clutch, so that the speed change of the automatic transmission is difficult. At this time, the timing of switching between the engagement states of the main clutch and the sub clutch is delicate, making control difficult. That is, if the auxiliary clutch is engaged too quickly after the main clutch is released, the transmission will be locked, resulting in a large shift shock, and if it is too late, the engine will rev up.

Means for Solving the Problems The present invention has been made against the background of the above circumstances.
The gist of this is that the input shaft is connected to the engine via the main clutch, the output shaft is connected to the drive wheels,
The system includes a plurality of types of gear pairs for transmitting the power of the human power shaft to the output shaft at mutually different gear ratios, and a shift member operated to select the gear pair, and the shift member is automatically operated. An automatic transmission for a vehicle of a type that transmits power transmitted from the engine to the drive wheels at a desired gear ratio when operated, the automatic transmission being provided between the input shaft and the output shaft, and (2) a shift control device that maintains the main clutch in an engaged state and brings the auxiliary clutch into a semi-engaged state when switching between the gear pairs. There is a particular thing.

Operation and Effects of the Invention With this structure, the sub-clutch is connected in series with the main clutch by being provided between the human power shaft and the output shaft, and when switching between gear pairs, the shift control device Since the main clutch is maintained in an engaged state while the sub clutch is brought into a semi-engaged state, when the automatic transmission is shifted, the vehicle is driven by the power transmitted via the sub clutch. As a result, for example, when shifting up, the decrease in acceleration feeling during gear changes is alleviated, but when the engine speed is reduced due to engagement of the auxiliary clutch, the previously existing gear pair changes to the next gear pair. It can be switched quickly. Therefore, there is no need for delicate timing control between the main clutch and the sub clutch.
The shift shock and engine revving caused by timing control can be largely eliminated, and the control device can be simplified.

EXAMPLE Hereinafter, an example of the present invention will be described in detail based on the drawings.

In FIG. 1, power from a vehicle engine 10 is transmitted to drive wheels 18 via a first clutch 12, a parallel two-shaft synchronous mesh type stepped transmission 14, and a differential gear 16.

The first clutch 12, the stepped transmission 14, the controller 102, which will be described later, and the like constitute the automatic transmission of this embodiment.

The first clutch 12 is hydraulic and is provided between the crankshaft 20 of the engine 10 and the input shaft 22 of the transmission 14, and is connected to a rotor 24 connected to the crankshaft 20 via a damper 21. A piston 26 that presses the rotor 24 when hydraulic pressure is applied is housed in the clutch case 28 .

The transmission 14 is for a front engine front wheel drive (FF) type vehicle, and includes an input shaft 22 and an output shaft 30 disposed parallel to each other in a housing 32. Between the output shaft 30 and the output shaft 30, there are a plurality of types of gear pairs, that is, a first speed gear pair, a second speed gear pair,
Power is transmitted through a third gear pair, a fourth gear pair, a fifth gear pair, and a reverse gear (not shown).

The first gear pair includes a first fixed gear 34 fixed to the input shaft 22, a first rotary gear 36 rotatably supported by the output shaft 30 while meshing with the first fixed gear 34, and a second rotating gear 36. The speed gear pair is a second fixed gear 3 fixed to the input shaft 22.
8 and a second rotary gear 40 that is rotatably supported by the output shaft 30 in a meshed state, and the third speed gear pair is a third fixed gear 42 that is fixed to the human power shaft 22 and A third rotary gear 44 is rotatably supported on the output shaft 30 in a meshed state, and a fourth gear pair is supported on the input shaft 22 so as to be engageable and detachable via a second clutch 54. The fifth speed gear pair consists of a fourth rotary gear 46 fixed to the output shaft 30 and a fourth fixed gear 48 fixed to the output shaft 30 in mesh with the fourth rotary gear 46 .
The output shaft 3 is meshed with the fixed gear 50.
0 and a fifth rotary gear 52 rotatably supported. Thus, the second clutch 54 is provided in the fourth gear pair and is positioned in series with the first clutch 12. The second clutch 54 is hydraulic, and
A rotor 25 connected to the input shaft 22, a piston 27 that presses the rotor 25 when hydraulic pressure is applied, and a piston 27 that accommodates them and is fixed to the fourth rotating gear 46 so that it can rotate relative to the input shaft 22. The clutch case 29 is supported by a clutch case 29.

The first rotary gear 36 and the second rotary gear 40 are selectively engaged with the output shaft 30 so that they cannot rotate relative to each other by a first synchronizer 56 provided on the output shaft 30. In addition, the third rotating gear 44 and the fifth rotating gear 52
Similarly, the second synchronizer 58 provided on the output shaft 30
Alternatively, it can be engaged with the output shaft 30 in a relatively non-rotatable manner.

First synchronizer 56. As shown in Fig. 2, the output shaft 3
A hub 60 fixed at 0, a first sleeve 64 spline-fitted to the hub 60 and driven in the axial direction by the first hydraulic cylinder 62, and movable together with the first sleeve 64 on the inner peripheral side of the first sleeve 64. key 66 provided in
, a spring 68 that urges the key 66 toward the outer circumferential side, outer circumferential teeth 70 and 72 formed on the first rotary gear 36 and the second rotary gear 40, respectively, and the first sleeve 64, the first rotary gear 36, and the second rotary gear 40. It includes synchronizing rings 74 and 76 respectively disposed between the two rotating gears 40, and when the first sleeve 64 is moved toward the first rotating gear 36 by the first hydraulic cylinder 62, the synchronizing rings 74 is pressed against the first rotary gear 36 via the key 66. When the rotations of the hub 60 and the first rotary gear 36 are synchronized by mutual friction between the conical friction surfaces 78 and 80 formed on the first rotary gear 36 and the synchronization ring 74, the rotation of the first sleeve 64 is further synchronized. Movement is allowed so that the inner teeth of the first sleeve 64 and the outer teeth 70 of the first rotary gear 36 mesh with each other.

The second synchronizer 58 is also configured in the same manner as the first synchronizer 56, and is spline-fitted to a hub 60 fixed to the output shaft 30, and is driven in the axial direction by a second hydraulic cylinder 82. A sleeve 84 is provided.

The engine IO is provided with an engine rotation sensor 100 for detecting its rotation speed.
A rotation signal SR corresponding to a rotation speed Ne of 0 is supplied to the controller 102. The accelerator pedal 104 of the vehicle is provided with an accelerator sensor 106 for detecting its operation ff1Acc.
An accelerator signal SA representing c c is supplied to the controller 102 .

A vehicle speed sensor 108 is provided near the output shaft 30, and a signal S■ corresponding to the rotational speed of the output shaft 30, that is, the vehicle speed ■ is supplied to the controller 102. Input shaft 1
An input shaft rotation sensor 110 is provided near the input shaft 22, and detects the rotation speed N! of the input shaft 22. A signal SI corresponding to is supplied to the controller 102. The transmission 14 is provided with a gear position sensor 112 for detecting the actual gear position, and a signal SG representing the actual gear position is sent to the controller 10.
2. Furthermore, the shift operation lever 11 of the vehicle
4 includes an operation position sensor 1 for detecting the operation position.
16 is provided, and a signal SL representing a substitute position of the shift lever 114 is supplied to the controller 102.

The controller 102 includes a RAM 118, a ROM 120,
It is a so-called microcomputer that includes a CPU 122, a human power interface 124, an output interface 126, etc., and uses the storage function of the RAM 118.
The input signal is processed according to a program stored in advance in the M120, and a drive signal BD is supplied to the throttle actuator 128, and the first clutch 12 and the second clutch 54, the first hydraulic cylinder 62 and the second hydraulic cylinder 82 are operated. For actuation, drive signals are provided to the solenoid valves 132, 134, 136, 138 of the hydraulic control circuit 130, respectively. This hydraulic control circuit 130 includes a hydraulic pump (not shown) driven by the engine lO, etc., and controls hydraulic pressure to the first clutch 12, the second clutch 54, and the first clutch in response to the operation of the solenoid valves 132, 134, 136, and It is supplied to the hydraulic cylinder 62 and the second hydraulic cylinder 82, respectively.

The first hydraulic cylinder 62 and the second hydraulic cylinder 82 are
A large diameter piston 90 is slidably fitted in a large diameter portion of a stepped cylinder bore, and a small diameter piston 94 is slidably fitted in a small diameter portion of the cylinder bore and fixed to a cylinder loft 92. By applying hydraulic pressure to the large diameter portion, the cylinder rod 92 is pushed out the most, and by applying hydraulic pressure to the small diameter portion, the cylinder rod 92 is retracted the most, and hydraulic pressure is applied to the large diameter portion and the small diameter portion. is applied to the cylinder rod 9.
2 is placed in a neutral position. As a result, for example, the first hydraulic cylinder 62 positions the first sleeve 64 in three positions: a neutral position, a position on the first rotary gear 36 side, and a position on the second rotary gear 40 side via the shift fork 141. Similarly, the second hydraulic cylinder 82 moves the second sleeve 84 to the neutral position and the third rotating gear 44 to the neutral position.
It is positioned through the shift fork 142 to three positions: the side position and the position of the fifth rotary gear 52.

Throttle valve 14 provided in the intake pipe of engine 10
0 is driven by the throttle actuator 128, and is normally positioned in accordance with the drive signal BD from the controller 102 so that the throttle opening θ corresponds to the accelerator operation 1Acc. The type 2 valves 132 and 134 are for driving the first hydraulic cylinder 62 and the second hydraulic cylinder 82, respectively, and when activated, the hydraulic pressure for obtaining a predetermined gear stage of the speed change N14 is controlled by the corresponding hydraulic pressure. Supply to cylinder. The electromagnetic valves 136 and 138 control the engagement of the first clutch 12 and the second clutch 54, respectively, and when activated, supply hydraulic pressure to engage the clutches.

The operation of this embodiment will be explained below.

In the controller 102, the CPU 122 selects a control mode such as start control, neutral control, shift control, engine brake control, etc. according to vehicle condition parameters. When the speed change control mode is selected while the vehicle is running, the CPU 122 operates the solenoid valve 136 to constantly engage the first clutch 12. In the above-mentioned shift control, the CPU 122 selects a shift pattern corresponding to the current gear from a plurality of shift patterns (shift diagrams) recorded in advance in the ROM 120, and selects a shift pattern corresponding to the current gear position based on the vehicle speed, accelerator operation amount, etc. and issue a shift command to obtain the required gear. In such a case, shifts are automatically performed from each gear to a commanded predetermined gear in a predetermined order. For example, if an upshift command is issued while driving in 1st or 2nd gear, the shift to 2nd or 3rd gear will be performed according to the series of steps shown in Figure 3. is executed similarly and automatically. Also,
When a downshift command is issued while the vehicle is running in second or third speed, a shift to first or second speed is similarly executed according to a series of steps shown in FIG. In the shift operations shown in FIGS. 3 and 4, the throttle valve opening .theta. and the engaged state of the first clutch 12 are maintained as they are.

For example, in an upshift from 1st speed to 2nd speed, step SUI in FIG. 3 is first executed to start supplying hydraulic fluid to the second clutch 54, which had been in a disengaged state. At the same time, the first rotating gear 3
The first sleeve 64 located on the 6 side is connected to the second rotating gear 4
Hydraulic pressure for positioning on the 0 side is supplied to the first hydraulic cylinder 62. Point A in FIG. 5 shows this state. As a result, the second clutch 54 is brought into a semi-engaged state, and the power of the engine 10 is transmitted through it, so that the first
The power transmitted through the synchronizer 56 begins to decrease. A biasing force for positioning the first sleeve 64 in its neutral position has already been applied from the first hydraulic cylinder 62, and the first sleeve 64, which had previously been difficult to pull out from the outer teeth 70 of the first rotary gear 36 due to the frictional force, Sleeve 64 is the first one! When the power transmitted through the 111 device 56 approaches zero, it overcomes the frictional force and is pulled out of the outer tooth 70 and first moved to the neutral position. Point B in FIG. 5 shows this state.

When it is determined in step SU2 that the first sleeve 64 has been moved to the neutral position, step SU3 is executed to further increase the hydraulic pressure supplied to the second clutch 54, and the first hydraulic pressure Hydraulic pressure is supplied to the cylinder 62, and a biasing force is applied to the first sleeve 64 to position it toward the second rotating gear 40 side. In this manner, power is transmitted through the second clutch 54 and the first synchronizer 56, so that the engine 10
When the rotational speed of is reduced to the rotational speed at which the second gear stage is established, the first sleeve 64, which had been blocked by the synchronizing ring 76, is moved and the outer circumference tiJ72 of the second rotating gear 40 and the first sleeve 64 are moved. When engaged, power is transmitted via the second gear pair. Point 0 in FIG. 5 indicates this state.

When it is determined in step SU4 that the second speed gear pair is established, step SU5 is executed and the second speed gear pair is established.
The hydraulic pressure supplied to the clutch 54 begins to be discharged. As a result, the transmission torque of the second clutch 54 starts to decrease at point D in FIG.
When the transmission torque of the second clutch 54 becomes zero as shown by the dot, the power is transmitted exclusively through the second speed gear pair and the first synchronizer 56, so the output torque of the transmission 14 becomes T2. Here, from point A to point E in Figure 5 is 0.
．． The time is about 4 seconds. In addition, T1 in FIG. 5 indicates the transmission 14 when power is transmitted by the first gear pair.
T4 is the output torque of the transmission 14 when power is transmitted by the fourth gear pair.

In this way, if an upshift command is issued while the vehicle is running in the first or second gear, no interruption of power transmission occurs during the gear shift period of the stepped transmission 14. , a suitable speed change feeling can be obtained.

Furthermore, in this embodiment, the gear shift of the transmission 14 is executed by changing the engagement state of the second clutch 54 while the first clutch 12 is in the engaged state, so that the first clutch 12 and the second clutch 54 are engaged. This eliminates the need for delicate timing control in switching the engagement state between 54 and 54, and the shift shock and engine revving caused by the timing control are largely eliminated, and the control device becomes simpler.

On the other hand, for example, if a downshift command is issued while driving in third gear, step SD, 1 in FIG.
At the same time as the supply of hydraulic oil to the
Hydraulic pressure is supplied to the second hydraulic cylinder 82 to position the second sleeve 84 located on the rotating gear 44 side to the neutral side.

8° in FIG. 6 indicates this state. As a result, the second clutch 54 is brought into a semi-engaged state, and the power of the engine 10 is transmitted through it, so that the second synchronizer 5
8 begins to transmit less power than before. A biasing force has already been applied to the second sleeve 84 from the second hydraulic cylinder 82 to position it in the neutral position, and the second sleeve has previously been difficult to remove from the outer teeth of the third rotary gear 36 due to frictional force. When the υ1 force transmitted through the second synchronizer 58 approaches zero, the tooth 84 overcomes the frictional force and comes out of the outer tooth, and is first moved to the neutral position. Bo in FIG. 6 shows this state.

When it is determined in step SD2 that the second sleeve 84 has been moved to the neutral position, step SD3 is executed, and the hydraulic pressure supplied to the second clutch 54 starts to decrease, and the first sleeve 64 Hydraulic pressure for moving the sleeve from the neutral position toward the second rotating gear 40 is supplied to the first hydraulic cylinder 62, and the first sleeve 64
A biasing force is applied to position the second rotary gear 40 toward the second rotary gear 40. In this manner, the power transmitted through the second clutch 54 is decreased while the power transmitted through the first synchronizer 56 is increased, thereby bringing the rotational speed of the engine 10 into second gear. When the rotational speed is increased toward and reaches the rotational speed at which the gear stage is established, the first sleeve 64, which was previously blocked by the synchronizing ring 76, is moved and the outer peripheral tooth 7 of the second rotary gear 40 is moved.
2, and the second gear stage is established. Point C' in FIG. 6 shows this state.

When it is determined in step SD4 that the second gear stage has been established, step SD5 is executed and the second gear stage is established.
The hydraulic pressure supplied to the clutch 54 is exhausted.

This results in the glue shown in Figure 6.

At this point, the transmission torque of the second clutch 54 starts to decrease, and when the transmission torque of the second clutch 54 becomes zero as shown at point E° in FIG. Since power is transmitted through the synchronizer 56, the output torque of the transmission 14 is T2. Here, the sixth
T3 in the figure is the output torque of the transmission 14 when power is transmitted by the third speed gear pair.

In this way, when a shift command for a downshift is issued while driving in the second or third gear, the power is transferred during the gear shift of the stepped transmission 14, as in the case of an upshift. No transmission interruption occurs. Further, in this embodiment as well, the gear change of the transmission 14 is executed by changing the engagement state of the second clutch 54 while the first clutch 12 is in the engaged state. This eliminates the need for delicate timing control in changing the engagement state between 54 and 54.
This greatly eliminates engine revs and engine revs, and simplifies the control system.

Upshifting from third speed to fourth speed is automatically performed by executing steps similar to steps SUI to SU3 in FIG. 3 above. In this case, in the step corresponding to step SU3, the synchronizer is not actuated and hydraulic oil is supplied to fully engage the second clutch 54. Further, the downshift from the fourth speed to the third speed is automatically performed by executing steps similar to steps SD3 to SD5 in FIG. 4. In this way, the same effect as the amplifier shift and downshift described above can be obtained with the amplifier shift to the fourth speed and the downshift from the fourth speed.

Upshifting from 4th gear to 5th gear is performed using the second clutch 5.
At the same time as releasing the throttle valve 14 for a period of -
0 is fully closed, the first clutch 12 is once released, and during this time the second synchronizer 58 is operated to mesh the second sleeve 84 with the fifth rotary gear 52, thereby automatically performing this operation.

Further, the downshift from the fifth speed to the fourth speed is performed by the reverse procedure to the above-mentioned upshift. In such a shift between the fourth and fifth speeds, the throttle/nottle valve 140 is once fully closed and the first clutch 12 is once released, so power transmission is interrupted. When shifting between the fourth and fifth speeds, the transmission gear ratio is small and the driving force of the vehicle is small, so interruption of power transmission does not inherently pose a problem.

As described above, according to this embodiment, when shifting between low speed gears of the transmission 14, the first clutch 12 is in the engaged state and the second clutch 54 is in the half-engaged state, so that multiple types of gears can be selected. Since gear pair switching is performed, delicate timing control between the first clutch 12 and the second clutch 54 is not required.

Therefore, the shift shock and engine revving caused by the timing control can be largely eliminated, and the control device can be simplified.

Further, according to this embodiment, since the second clutch 54 is provided on the fourth speed gear pair, the second clutch 54 is partially engaged, compared to the conventional case where the second clutch 54 is provided on the fifth speed gear pair. This has the advantage that the drive torque obtained by the combination is relatively large, and at the same time, the amount of slippage is reduced and durability is increased.

Further, according to this embodiment, the second clutch 54 is connected to the input shaft 2.
Since the clutch is arranged in series with the first clutch 12 via the clutch 12, the input side rotating shaft of the transmission 14 is a concentric double (sleeve) ) It is not necessary to provide two shafts having a structure of 1.), and there is an advantage that the structure of the transmission 14 is simplified.

In addition, conventionally, the gear pair for the fifth gear is completed by engagement of the second clutch, so that the gear pair for the fifth gear is completed when the second clutch is engaged.
A damper for absorbing friction is normally required to improve drivability, but according to this embodiment, the fifth speed gear pair is completed by the engagement of the first clutch 12 with the damper 21. Therefore, there is no need to provide the second clutch 54 with a damper.

Next, another embodiment of the transmission 14 will be described. In the following description, parts common to those in the above-described embodiments are designated by the same reference numerals, and the description thereof will be omitted.

In FIG. 7, the transmission 14 is for a front engine rear wheel drive (FR) type vehicle, and includes an input shaft 22.
and an output shaft 30 are arranged in a straight line, and a counter shaft 144 is parallel to the human power shaft 22 and the output shaft 30.
is installed.

The counter shaft 144 and the input shaft 22 are operatively connected via a pair of connecting gears 146 and 148 that are fixed thereto and mesh with each other.
44 is adapted to be rotationally driven in the opposite direction by the human power shaft 22. A second clutch 54 is provided between the shaft ends of the human power shaft 22 and the output shaft 30, and when the second clutch 54 is engaged, power is transmitted at a gear ratio of "1". In other words, the fourth speed is established.

Between the input shaft 22 and the output shaft 30, or directly between the counter shaft 144 and the output shaft 30, there are a plurality of types of gear pairs, that is, a first speed gear pair, a second speed gear pair, Power is transmitted through a third gear pair and a fifth gear pair.

The first gear pair includes a first fixed gear 150 fixed to the output shaft 30, a first rotary gear 152 rotatably supported by the counter shaft 144 in mesh with the first fixed gear 150, and a second rotating gear 152. The second gear pair fixed to the output shaft 30 is
A second rotary gear 156 is rotatably supported by the counter shaft 144 while being meshed with the fixed gear 154.
The third speed gear pair consists of a third fixed gear 158 fixed to the output shaft 30 and a third rotary gear 1 rotatably supported by the counter shaft 144 in mesh with the third fixed gear 158.
60, and the fifth speed gear pair consists of a fifth fixed gear 162 fixed to the output shaft 30 and a fifth rotary gear 164 rotatably supported by the counter shaft 144 in mesh with the fifth fixed gear 162. Become.

Also in this embodiment, when the first sleeve 64 is engaged with the first rotary gear 152 by the first synchronizer 56, the first
The first sleeve 64 is the second rotating gear, and the gear 15 is the second gear.
When the second sleeve 84 of the second synchronizer 58 is engaged with the third rotary gear 160, the second gear stage is set. Fifth
When engaged with the rotating gear 164, the fifth gear stage is established.

Although one embodiment of the present invention has been described above based on the drawings,
The invention also applies in other aspects.

For example, in the embodiment described above, the second clutch 54 is disposed in the fourth gear train, but it could also be disposed in the third gear train.

Furthermore, in the transmission 14 shown in FIG.
Although five types of gear pairs up to speed are provided, for example, four types of gear pairs up to fourth speed, or three types of gear pairs up to third speed may be used.

Further, in the transmission 14 of the above-described embodiment, the synchronous device 56 for selectively engaging the output shaft 30 and the first rotary gear 36 or the second rotary gear 40 has a synchronization function. A synchronizing ring 74,76 is provided for generating the synchronizing force, but the synchronizing ring 74,76 may not necessarily be provided since half-engagement of the second clutch 54 allows synchronization.

Note that the above-mentioned embodiment is merely one embodiment of the present invention, and various modifications may be made to the present invention without departing from the spirit thereof.

[Brief explanation of drawings]

FIG. 1 is a diagram illustrating the configuration of an embodiment of the present invention. FIG. 2 is a diagram illustrating the structure of the synchronization device shown in FIG. 1. FIGS. 3 and 4 are flowcharts illustrating the amplifier shift and downshift operations in the embodiment of FIG. 1, respectively. 5 and 6 are diagrams illustrating changes in engine rotational speed and transmission output torque during operation of the embodiment shown in FIG. 1 in the case of an upshift and a downshift, respectively. FIG. 7 is a schematic diagram showing the configuration of another example of the transmission. 10: Engine 12: First clutch (main clutch) 14: Transmission 18: Drive wheel 22: Human power shaft 30: Output shaft 54: Second clutch (auxiliary clutch) 102: Controller (shift control device) Fig. 2, Fig. 3 Figure 4 Figure 5rIA

Claims (1)

[Claims] (1) An input shaft connected to the engine via a main clutch, an output shaft connected to the drive wheels, and multiple types of gears for transmitting the power of the input shaft to the output shaft at mutually different gear ratios. and a shift member operated to select the gear pair, and by automatically operating the shift member, the power transmitted from the engine is transmitted to the drive wheels at a desired gear ratio. An automatic transmission for a vehicle of the type, comprising: a sub-clutch provided between the input shaft and the output shaft to transmit power therebetween; and a sub-clutch that engages the main clutch when switching between the gear pair. An automatic transmission device for a vehicle, comprising: a shift control device that brings the sub-clutch into a semi-engaged state while maintaining the sub-clutch in an engaged state.