JP2003336734A - Control device and control method for automatic transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent deterioration of drivability caused by torque disconnection in a period in speed change before input shaft rotation reaches target speed in which power generated by an engine is not transmitted to tires. <P>SOLUTION: This device comprises a main clutch release detecting means to detect a main clutch (starting clutch) released, and a neutral state detecting means to detect an engagement clutch in a neutral state. As the main clutch (starting clutch) released, with the engagement clutch in the neutral state, input shaft speed of a transmission is decreased or increased by controlling a subsidiary clutch (assist clutch/bypass clutch). <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device and control method for an automatic transmission based on the structure of a gear type transmission.

[0002]

2. Description of the Related Art Based on an existing manual transmission,
A transmission that automates this is known. In this kind of automatic transmission, a plurality of gears are arranged in the axial direction, and a plurality of meshing clutches for switching the power transmission path of each gear are provided.

The shift operation is executed by automatically operating the dog clutch with an electric or fluid pressure type actuator. This automatic transmission is superior in power transmission efficiency to a normal automatic transmission (so-called AT) mainly composed of planetary gears, friction engagement elements (clutch, brake) and the like. Further, since the number of parts constituting the transmission is small, it is easy to reduce the weight and the cost is great.

However, in gear shifting in the above automatic transmission, the main clutch for transmitting the power of the engine to the input shaft is released, and the mesh clutch is operated during the gear shifting, so that the power of the engine is temporarily changed. Is not transmitted to the tires, so-called torque interruption occurs, which causes a driver to feel uncomfortable as a shift shock.

Then, regarding such an automatic transmission,
For example, Japanese Unexamined Patent Application Publication No. 2001-227599 discloses a configuration including a sub-clutch for suppressing torque interruption during shifting. This sub-clutch is provided with a third intermediate shaft in addition to the input shaft and output shaft of the gear type transmission, and the sub-clutch and the gear are installed on this intermediate shaft. Then, at the time of gear shift, as shown in FIG. 11, the main clutch provided between the engine and the input shaft is not released, the torque of the sub clutch is variably controlled, and the power from the engine is transmitted to the output shaft. As a result, the interruption of torque during the shift is suppressed and the shift performance is improved.

Similarly, for example, Japanese Patent Laid-Open No. 2001-28047.
Japanese Unexamined Patent Publication No. 4 discloses a configuration including a brake mechanism for suppressing the torque interruption during gear shifting.
This brake mechanism is installed on the counter shaft of a gear type transmission, and when the main clutch is disengaged and the dog clutch is in a neutral state during gear shifting, the brake mechanism is operated to rotate in conjunction with the counter shaft. Reduce the input shaft rotation to the target speed. Therefore, the time required for the operation of the dog clutch is shortened and the interruption of the torque is suppressed.

[0007]

However, in the above-described conventional automatic transmission, the above-mentioned brake mechanism can apply only so-called up-shift, which reduces the rotation of the input shaft to perform gear shifting, and its effect is limited. It can only be obtained with patterns. Therefore, in a downshift requiring an acceleration request, the uncomfortable feeling due to the interruption of the torque still remains.

Therefore, an object of the present invention is to reduce the time required for the input shaft rotation to reach the target rotation speed regardless of shift up or shift down, and to suppress torque interruption. To provide a control device and a control method.

Another object of the present invention is to reduce the load on the synchronizing mechanism for synchronizing the shaft rotation, which is an element constituting the dog clutch, and to improve the durability of the synchronizing mechanism. is there.

[0010]

In order to achieve the above object, the present invention detects that the main clutch (so-called starting clutch) is released, and the dog clutch is in a neutral state (so-called neutral state). When the main clutch is disengaged and the dog clutch is in the neutral state, the sub-clutch (the clutch for transmitting torque to the transmission output shaft even during the shift) is controlled to detect the shift This is to reduce or increase the rotation speed of the machine input shaft.

With this configuration, the time required for the input shaft rotation to reach the target rotation speed can be shortened and torque interruption can be suppressed regardless of the shift up or shift down.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION A control device and control method for an automatic transmission according to a first embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a block diagram showing an overall configuration of a control device for an automatic transmission according to an embodiment of the present invention.

The power generated by the engine 101 is input to the transmission 103 via the main clutch 102.
The main clutch 102 is engaged and disengaged by hydraulic control, and the power of the engine 101 is transmitted to the transmission 103.
To the input shaft of or cut off. The engagement / disengagement state of the main clutch 102 is detected by the main clutch disengagement state detection means 108, and the control device 109
Is input to.

The gear type speed change mechanism 105 comprises an input shaft, a counter shaft and an output shaft, and a gear train which is mounted on each shaft and is in a predetermined constant meshing state. The gear trains on the output shaft are respectively output shafts. It is mounted so that it can rotate freely. The gear type speed change mechanism 105 includes the dog clutch 1
By 04, a predetermined gear in the gear train is operated to rotate together with the output shaft. As a result, a predetermined gear ratio is set in the transmission 103. Further, the neutral state detecting means 107 detects whether the dog clutch 104 is connected to a predetermined gear or is in a neutral state, and is input to the control device 109. Further, the transmission 103 is provided with a sub-clutch 106, and by setting the sub-clutch 106 in a half-clutch state, a predetermined shift speed can be formed, so that the input shaft rotation can be changed.

The control device 109 receives signals such as the rotational speeds Ni and No of each shaft constituting the gear type speed change mechanism 105 and the driver's accelerator opening APS, and based on these signals, the main clutch 102 and the above-mentioned. A basic program for operating the dog clutch 104 to perform automatic gear shifting, and when the main clutch 102 is released and the dog clutch 104 is in a neutral state, the sub clutch 106 is in a half-clutch state and the input shaft rotation is changed. It is a microcomputer having a program. Here, the release of the main clutch means that power transmission from the engine 101 to the transmission 103 is cut off.

With the above structure, the input shaft rotation is changed by the action of the sub-clutch during gear shifting.
The time required to reach the target speed can be shortened.
Therefore, the torque interruption time is shortened and the shift shock is suppressed.

FIG. 2 shows the advancement 5 according to the first embodiment of the invention.
FIG. 3 is a skeleton diagram showing an automatic transmission having a number of stages. This transmission shown as an example is a trunk axle laid out vertically on the vehicle. In the transmission case, an input shaft 1, an output shaft 2, an idler shaft 3, and a counter shaft 4 are arranged in parallel with each other. The power input from the engine 0 to the transmission is basically transmitted from the input shaft 1 to the output shaft 2 via a specific transmission gear train.

Main clutch 5 which is a single plate type clutch
Transmits hydraulic power to the crankshaft of the engine 0 to the input shaft 1 on the automatic transmission side or shuts off the power by hydraulic control.

The gear type transmission has the output shaft 2 at the first speed, the second speed,
3rd, 4th, 5th and reverse gear driven gears 13, 1
1, 9, 7, 15 and 19 are provided in a freely rotatable state. On the other hand, the counter shaft 4 is arranged in parallel with the output shaft 2, and the driven gears 13, 11, 9,
1st gear, 2nd gear, 3rd gear, 4th gear that always meshes with 7 and 15
The fifth and fifth speed drive gears 12, 10, 8, 6, and 14 are fixedly mounted.
Similarly, idler gears 21 and 22 are fixedly attached to the idler shaft 3 arranged in parallel, and the idle gear 21 is a drive gear 23 in the reverse gear.
And the idle gear 22 is the driven gear 19 in the reverse gear.
Always meshes with.

Switching of each transmission gear train is performed by three dog clutches 16-18. The first dog clutch 16 is provided on the output shaft 2 between the first speed driven gear 13 and the second speed driven gear 11. The second dog clutch 17 is provided on the output shaft 2 between the third speed driven gear 9 and the fourth speed driven gear 7.
It is provided above. Similarly, the third dog clutch 18 is provided on the output shaft 2 near the right side of the fifth speed driven gear 15.

The structure of each of the dog clutches 16 to 18 is well known, but the synchronizing sleeves 16a to 18a.
The axial shift of is automatically controlled by hydraulic pressure.
For example, when the shift speed is set to the first speed, the synchro sleeve 16a is hydraulically shifted to the right with the synchro sleeves 17a and 18a set to the neutral position. As the shift amount increases, the rotations of the synchronizing sleeve 16a and the first speed driven gear 13 are synchronized with each other via the synchronizer ring 16c. Then, when these members 13 and 16a are synchronized, the outer spline integrally formed with the first speed driven gear 13 is moved to the sleeve 1
The inner spline of 6a is fitted with the spline. Here, the synchro sleeve 16a is always spline-fitted with the synchro hub 16b that rotates integrally with the output shaft 2. Therefore, the power transmitted from the input shaft 1 to the counter shaft 4 via the fourth speed driven gear 7 and the fourth speed driven gear 6 is passed through the first speed drive gear 12, the first speed driven gear 13, the synchronizing sleeve 16a and the synchronizing hub 16b. , To the output shaft 2.

On the other hand, when the shift speed is set to the second speed, the synchro sleeve 16a is hydraulically shifted to the left with the synchro sleeves 17a and 18a set to the neutral position. Further, when the shift speed is set to the third speed or the fourth speed, the synchro sleeve 17a is shifted, and when it is set to the fifth speed, the synchro sleeve 18a is shifted (other synchro sleeves are set to the neutral position). ).

During forward movement except during gear shifting, the power of the input shaft 1 is transmitted to the output shaft 2 via the gear train selected by operating the assist clutches 16-18.
As a result, power is transmitted to the drive wheels and the vehicle moves in the forward direction. When the vehicle is moving backward, the synchro sleeve 18a is hydraulically shifted to the right while the synchro sleeves 16a and 17a are set to the neutral position. Therefore, the power of the counter shaft 4 is transmitted from the reverse drive gear 23, the idle gear 21, the intermediate shaft 3, the idle gear 22, the reverse driven gear 19, the synchro sleeve 18a, and the synchro hub 18b to the output shaft 2.
Be transmitted to. Therefore, the rotation direction of the output shaft 2 is opposite to that in the forward movement, and the vehicle moves in the backward direction.

Next, the torque transmission path will be described.
Similar to FIG. 2, FIG. 12 is a skeleton diagram showing an automatic transmission with five forward gears according to the first embodiment of the present invention, and is a diagram showing a transmission path of torque generated in the engine. The structure of each part of the transmission is the same as in FIG. For example, assuming that the 1st speed state is the above-mentioned first connection, the torque generated in the engine 0 is the input shaft 1st-4th speed driven gear 7-4th speed drive gear 6
-Counter shaft 4-1 speed drive gear 12-1 speed driven gear 13-Transmitted to the output shaft 2 via the dog clutch 16 and a torque transmission path is formed like the transmission path 121.

Similarly, assuming that the second speed state is the second connection described above, the torque generated in the engine 0 causes the torque generated in the engine 0 to be the input shaft 1-4 speed driven gear 7-4 speed drive gear 6-counter shaft 4-2.
The high-speed drive gear 10-2 is transmitted to the output shaft 2 through the second driven gear 11-the dog clutch 16 and a torque transmission path is formed like the transmission path 122.

Further, when switching the transmission path, the transmission path 123 can be formed by controlling (engaging) the sub-clutch 24. Transmission path 123
The torque generated in the engine 0 is the output shaft 2 via the input shaft 1-4 speed driven gear 7-4 speed drive gear 6-counter shaft 4-assist drive gear 25-assist clutch 24-assist drive gear 26. The torque is transmitted to.

Here, the basic operation of shifting will be described. When the shift stage is determined by the microcomputer of the control device 109 shown in FIG. 1 from the driver's intention of operation or the running state of the vehicle, the main clutch 5 is released and the engine 0
The power transmission from is cut off. Next, after the dog clutches 16 to 18 are brought into a neutral state, one of the synchronizing sleeves is shifted to form a predetermined shift speed. Then, the counter shaft (that is, the input shaft) is rotationally synchronized by the action of the synchronizer ring. Then, when the shift operation of the synchronizing sleeve is completely completed, the engagement of the main clutch is started. That is, the period during which the dog clutch is operated is the time for interrupting the torque, and it is necessary to shorten this time.

The time required for the rotation synchronization is about 100 to 300 ms, although it depends on the difference in the number of rotations between the synchro hub and the driven gear or the shift force of the synchro sleeve. If the shift force is increased to shorten this time, abnormal noise (gear squeal) may occur when the rotation is synchronized,
It also promotes damage to the synchronizer ring.

Therefore, the output shaft 2 is provided with a sub-clutch 24 which is a hydraulically controlled multi-plate clutch, and the input shaft rotation is changed by setting the sub-clutch 24 in a half-clutch state. When the pressing force of the sub clutch 24 is increased, the counter shaft 4
Since power is transmitted from the assist drive gear 25 fixedly attached to the output shaft 2 to the output shaft 2 via the assist driven gear 26 fixedly attached to the output shaft 2,
It is possible to form a predetermined shift speed. Further, there is an advantage that the time required for the rotation synchronization is short because the rotation speed is changed by the shearing force of the oil instead of the rotation synchronization by the contact friction as in the synchronizer ring.

Here, the above-mentioned Japanese Patent Laid-Open No. 2001-28047.
In the transmission described in Japanese Patent Publication No. 4, the input shaft rotation speed is reduced by the brake mechanism. However, although the input shaft rotation is reduced during the upshift, the rotation must be increased during the downshift. Therefore, as shown in FIG. 5, the gear ratio formed by the assist gears 25 and 26 is set to a gear ratio corresponding to 3.5 speed. As a result, an upshift from a gear ratio in which the gear ratio before shifting is larger than 3.5th gear (for example, 1-2 shifting, 2-3
(Shifting) and downshifting from a gear ratio in which the gear ratio before shifting is smaller than the 3.5th speed (for example, 5-4 shifting, 5-3 shifting), the input shaft rotation is reduced or increased by the sub-clutch 24. .

With the above configuration, the time required for the input shaft rotation to reach the target rotation can be shortened. Therefore, the torque interruption time is shortened and the shift shock is suppressed. As a result, the effect of reducing the load on the synchronizer ring and improving the durability can be obtained.

FIG. 3 is an explanatory view showing an example of the main clutch release detecting means of the automatic transmission according to this embodiment.

Main clutch 5 which is a single plate type clutch
Transmits the power of the crankshaft of the engine to the input shaft 1 on the automatic transmission side or shuts it off by hydraulic control. Specifically, as shown in FIG. 3, the flywheel 5a is directly connected to the crankshaft, and a clutch disc 5c is interposed between the flywheel 5a and the pressure plate 5b. This clutch disc 5
c is spline-fitted to the input shaft 1 via a clutch hub provided on the inner peripheral surface. Further, the release bearing 5d is attached so as to be slidable on the axis of the input shaft 1. The power of the crankshaft is transmitted to the input shaft 1 in a state where the pressure plate 5b strongly presses the clutch disc 5c toward the flywheel 5a by the clutch spring 5e. On the other hand, when hydraulic pressure is generated in the cylinder 5g, the release fork 5f that is interlocked with the push rod 5h acts and the release bearing 5d slides to the left side in FIG. Therefore, the clutch disc 5c becomes free, the transmission of power is cut off, and the main clutch 5 is released. A stroke sensor 5i is attached to the push rod 5h to detect the amount of movement of the push rod.
This stroke sensor 5i is the main clutch 10 of FIG.
It corresponds to the releasing means of 2. Here, the output signal of the stroke sensor 5i is input to the control device 109, and from the relationship between the clutch position and the transmission torque obtained by an experiment in advance,
The released state of the main clutch 5 can be determined.

FIG. 4 is an explanatory view showing an example of the neutral state detecting means of the automatic transmission according to the embodiment of the present invention.

A hydraulic pressure source 401 composed of an electric pump and an accumulator supplies hydraulic pressure for driving the shift actuator 402. Shift actuator 402
Is composed of a shift solenoid 403 connected to the hydraulic source 401 and a cylinder 405 connected to the output port of the shift solenoid 404. The solenoid is a pressure control valve that can move the cylinder 405 in mutually opposite directions, and uses the detection value of the stroke sensor 406 connected to the cylinder 405 as an input to perform PWM control of the microcomputer to enable the solenoid 405 to communicate with the cylinder 405. Connected shift fork 40
The action load for operating 7 is changed. As a result, the synchro sleeve of the dog clutch can be moved in the axial direction. Here, the stroke sensor 40
6 corresponds to the neutral state detecting means 107 in FIG. 1, and the output signal of the stroke sensor 406 is input to the control device 109,
The neutral state of the dog clutch can be determined from the data obtained by experiments in advance.

Next, the control method of the automatic transmission according to the first embodiment of the present invention will be described with reference to FIGS.

FIG. 6 is a flow chart showing a control method by the control device for an automatic transmission according to one embodiment of the present invention, and is a flow chart when a shift command is issued.
Further, the processing content shown in the flowchart of FIG.
It is a program installed in the microcomputer of the control device 109 shown in FIG.

In step S601 of FIG. 6, the current gear ratio GrGp is read from the gear ratio table data shown in FIG. Next, in step S602, similarly, the next gear ratio GrGpNxt after shifting is read from the gear ratio table data.
Next, in step S603, it is determined whether or not the process of changing the input shaft rotation using the sub clutch is executed. Specifically, when the shift pattern is an upshift and GrGp is larger than the assist gear ratio, the shift pattern is a downshift and the G
When either condition that rGp is larger than the assist gear ratio is satisfied, step S604 is executed.
Shift patterns that satisfy the above conditions include a 1-2 shift and a 2-3 shift. Further, as a shift pattern that satisfies the above conditions, there are 5-4 shift and 5-3 shift. Then, in step S604, the sub-clutch is controlled to execute the rotation speed matching control of the input shaft, and the time required to reach the target rotation is shortened. Details of step S604 will be described with reference to FIG.

According to the flow chart as described above,
Regardless of upshift or downshift, the sub-clutch can be used to adjust the rotational speed of the input shaft, and as a result, the torque interruption time during gear shifting can be shortened.

FIG. 7 is a flow chart showing a control method by the control device for the automatic transmission according to the embodiment of the present invention, and is a flow chart of the rotational speed adjustment control by the sub clutch. Further, the processing contents shown in the flowchart of FIG. 7 are programs installed in the microcomputer of the control device 109 shown in FIG.

In step S701 of FIG. 7, the main clutch position STASEN detected by the stroke sensor 5i shown in FIG. 3 is read. Next, in step S702, the shift position SFTSEN detected by the stroke sensor 406 shown in FIG. 4 is read. Next in step S7
In 03, it is determined from the values of STASEN and SFTSEEN that both the main clutch and the dog clutch are in the released state or the neutral state. If the determination result is YES, the process proceeds to step S704, and if the determination result is NO, the above steps S701 to S703 are repeated.
Next, in step S704, the sub-clutch hydraulic pressure is generated in order to bring the sub-clutch 24 shown in FIG. 3 into the half-clutch state. Next, in step S705, the input shaft speed N
The target value NiNxt of i is calculated, and specifically, the target value NiNxt is calculated by the following formula: output shaft rotation speed No × next gear ratio GrNxt. Next, in step S706, an end determination process for adjusting the rotation speed of the input shaft is performed. Specifically, the target input shaft rotation NiN
The difference between xt and the actual input shaft rotation Ni is calculated, and it is determined whether or not the absolute value is equal to or less than the rotation speed difference dNi obtained by an experiment in advance. Here, although dNi is a constant value in the above, the data may be tabulated so as to be optimum according to conditions such as a shift pattern. Step S7
If it is determined that the rotation speed adjustment is completed at 06, the process proceeds to step S707, and if it is determined that the rotation speed adjustment is not completed, steps S704 to S706 are repeated. Next, in step S707, the hydraulic pressure acting on the sub-clutch is set to zero in order to quickly disengage the sub-clutch, and the entire process is ended.

According to the flow chart as described above,
It is possible to adjust the rotation speed of the input shaft using the sub-clutch, and as a result, the torque interruption time during shifting is shortened. Further, since the dog clutch is operated to form the predetermined shift speed after performing all the processes of FIG. 7, the synchronous torque applied to the synchronizer ring can be reduced, and the durability of the synchronizer ring can be improved. .

Further, in step S603 of FIG. 6, it is determined whether or not to operate the sub-clutch.
Under the condition that the difference in rotation speed is small to be changed, as a result of the processing shown in FIG. Therefore, whether to control the sub-clutch only in a shift pattern having a relatively large rotational speed difference (for example, 1-3 shift, 5-3 shift), or whether to control the sub-clutch according to the difference between NiNxt and Ni. May be determined. That is, the control method may be such that the above process is executed according to the necessity of shortening the torque interruption time.

FIG. 8 is a time chart when the rotational speed adjustment by the sub-clutch shown in FIG. 7 is executed, and is a time chart when upshifting from the first speed to the second speed.

At the time to, when the control device 109 makes a shift decision of the 1-2 shift, the throttle opening command TTVO (not shown) for controlling the engine torque is decreased and the engine torque is decreased. for,
The output shaft torque To also decreases. Then, at time t1, the hydraulic pressure acting on the clutch shown in FIG. 3 is controlled so as to release the main clutch near To = 0.
Here, the timing for releasing the main clutch is To =
If the time is relatively earlier than the time when it becomes 0, or if it is delayed, To changes rapidly and the occupant feels as a shift shock. Therefore, the timing for releasing the main clutch is set to an optimum value. Here, the engagement / disengagement state of the main clutch is the main clutch position STA.
SEN is detected by the stroke sensor shown in FIG. When the main clutch is released, the input shaft speed Ni starts to decrease due to running resistance. Further, when the disengagement of the main clutch is detected, the control device 1 issues a pressure command to the linear solenoids 403 and 404 shown in FIG. 4 so as to bring the dog clutch into a neutral state.
It outputs from 09. The stroke of the dog clutch is detected as the shift position SFTSEN by the stroke sensor 406 shown in FIG. Next, time t2
When the main clutch is disengaged and the dog clutch is determined to be in the neutral state, the pressure command ASTTq of the hydraulic pressure acting on the sub clutch is increased in order to bring the sub clutch into the half clutch state. Then, due to the action of the sub-clutch, Ni drops sharply. Next, at time t3, when Ni falls to the range of the synchronization determination rotation speed difference dNi, ASTTq is set to 0 to release the sub clutch. At the same time, a pressure command to the linear solenoids 403 and 404 is output from the control device 109 to engage the dog clutch with the second speed gear. Then, time t4
When SFTSEN strokes to the second speed position in, the main clutch is engaged and the engine torque returns to the state before the gear shift, so the output shaft torque increases and the gear shift ends.

As indicated by the broken line, if the input shaft rotation is synchronized by pressing the dog clutch without using the sub-clutch, the time required for the input shaft rotation to be synchronized becomes long. As a result, the time during which the torque drops until To drops to 0 becomes long, and drivability deteriorates.

As described above, by adjusting the rotation speed of the input shaft using the sub-clutch during gear shifting, it becomes possible to shorten the time for interrupting the torque.

FIG. 9 is a time chart when the rotational speed adjustment is performed by the sub-clutch shown in FIG. 7 described above, and is a time chart when an upshift from the fifth speed to the fourth speed.

When the accelerator pedal APS is depressed and the control unit 109 makes a shift decision of 5-4 shift at time to, a throttle opening command TTVO (not shown) for controlling the engine torque is issued. The output shaft torque T decreases because the engine torque decreases.
o also decreases. Then, at time t1, the hydraulic pressure acting on the clutch shown in FIG. 3 is controlled so as to release the main clutch near To = 0. Here, when the timing of releasing the main clutch is relatively early or late with respect to the time when To = 0, To changes suddenly and the occupant feels a shift shock.
Therefore, the timing for releasing the main clutch is set to an optimum value. Here, the disengaged state of the main clutch is the main clutch position STASEN,
It is detected by the stroke sensor shown in FIG. Further, when the disengagement of the main clutch is detected, a pressure command to the linear solenoids 403 and 404 shown in FIG.
It outputs from 09. The stroke of the dog clutch is detected as the shift position SFTSEN by the stroke sensor 406 shown in FIG. Next, time t2
When the main clutch is disengaged and the dog clutch is determined to be in the neutral state, the pressure command ASTTq of the hydraulic pressure acting on the sub clutch is increased in order to bring the sub clutch into the half clutch state. Then, due to the action of the sub-clutch, Ni rapidly rises. Next, time t
In 3, when Ni rises to the range of the synchronous judgment rotation speed difference dNi, ASTTq is set to 0 to release the sub clutch.
And At the same time, the controller 109 outputs a pressure command to the linear solenoids 403 and 404 in order to engage the dog clutch with the fourth speed gear. Then, at time t4, when SFTSEN strokes to the fourth speed position,
When the main clutch is engaged and the engine torque returns to a state corresponding to the accelerator opening, the output shaft torque increases and the gear shift ends.

Further, as shown by the broken line, if the input shaft rotation is attempted to be increased by pressing the dog clutch without using the sub-clutch, the time required until the input shaft rotation is synchronized becomes long. As a result, the time during which the torque drops until To drops to 0 becomes long, and drivability deteriorates.

As described above, by adjusting the rotational speed of the input shaft using the sub-clutch during gear shifting, it is possible to shorten the time for interrupting the torque. Further, in the case of downshift, if the meshing clutch is used to increase the rotation speed, the load on the synchronizer increases. As shown in FIG. 9, by increasing the input shaft rotation by the sub-clutch, the load on the synchronizer can be reduced, and the durability of the synchronizer is improved.

A structure similar to that of the automatic transmission shown in the first embodiment of the present invention described above is disclosed in Japanese Patent Laid-Open No. 2001-05037.
No. 9 is disclosed. Specifically, during shifting, when the main clutch is not released and the dog clutch is switched from the first connection to the second connection during transmission, torque is transmitted from the input shaft to the output shaft by controlling and engaging the sub-clutch. It is a system that forms a route. According to such a control device and control method, there is no interruption of torque during a shift in upshifting, and good shift quality can be obtained. However, there is a torque interruption time in the downshift as well. Therefore, in the downshift, if the input shaft rotation is increased by using the sub-clutch and the torque interruption time is shortened by the above control method, the drivability of the entire vehicle can be further improved.

FIG. 10 is a skeleton diagram showing an automatic transmission with five forward gears according to a second embodiment of the present invention. This transmission shown as an example is a trunk axle laid out vertically on the vehicle. The components of the automatic transmission according to the first embodiment of the present invention shown in FIG. 2 are substantially the same, and the same contents will be omitted. The dog clutch 16 provided on the output shaft 2 is eliminated, and the arrangement of the transmission gear train adjacent to the other dog clutches is changed. Specifically, the dog clutch 18 is provided with reverse gear trains 19 and 22 and second speed gear trains 11 and 10.
Further, as the assist gear train attached to the sub clutch 24, first speed gear trains 13 and 12 are provided, and a sub clutch 27 is newly provided on the output shaft 2.
A fifth speed gear train 15, 14 is attached as the seventh assist gear train. Then, these assist clutches 24, 27
By fully engaging the vehicle, it is possible to perform steady running in the first speed or the fifth speed. Further, at the time of gear shifting, the sub-clutch is operated to decrease or increase the input shaft rotation in order to shorten the torque interruption time as described above. Here, when shifting up, the sub-clutch 27 is operated to reduce the rotation of the input shaft. Further, during downshifting, the sub-clutch 24 is operated to reduce the rotation of the input shaft.

With such a structure, the torque interruption time can be shortened in all the shift patterns, and the shift quality of the entire vehicle can be improved. Further, since the dog clutch is omitted and the sub-clutch enables steady running, the structure of the transmission is simplified and the cost is reduced.

[0056]

The time required for the input shaft rotation to reach the target rotation is detected by detecting the released state of the main clutch and the neutral state of the meshing clutch and executing the rotation speed adjustment of the input shaft rotation by the sub clutch. It is possible to shorten the time, and it is possible to shorten the time for interrupting the torque.

[Brief description of drawings]

FIG. 1 is a block diagram showing an overall configuration of a control device for an automatic transmission according to a first embodiment of the present invention.

FIG. 2 is a skeleton diagram showing an automatic transmission with five forward gears according to the first embodiment of the present invention.

FIG. 3 is an explanatory view showing an example of a main clutch disengagement detection means of the automatic transmission according to the first embodiment of the present invention.

FIG. 4 is an explanatory diagram showing an example of a neutral state detecting means of the automatic transmission according to the first embodiment of the present invention.

FIG. 5 is an explanatory diagram showing a gear ratio of the automatic transmission according to the first embodiment of the present invention.

FIG. 6 is a flowchart showing a control method by the control device for the automatic transmission according to the embodiment of the present invention.

FIG. 7 is a flowchart showing a control method by the control device for the automatic transmission according to the embodiment of the present invention.

FIG. 8 is a time chart when the number of rotations is adjusted by the sub-clutch of the gear type transmission according to the embodiment of the present invention.

FIG. 9 is a time chart when the number of revolutions is adjusted by the sub-clutch of the gear type transmission according to the embodiment of the present invention.

FIG. 10 is a skeleton diagram showing an automatic transmission with five forward gears according to a second embodiment of the present invention.

FIG. 11 is a diagram showing a transmission output shaft torque.

FIG. 12 is a diagram showing a torque transmission path.

[Explanation of symbols]

101 ... Engine, 102 ... Main clutch, 103 ...
Transmission, 104 ... Meshing clutch, 105 ... Gear type transmission mechanism, 106 ... Sub clutch, 107 ... Neutral state detecting means, 108 ... Disengagement state detecting means, 109 ... Control device.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takashi Okada             7-1-1, Omika-cho, Hitachi-shi, Ibaraki Prefecture             Inside the Hitachi Research Laboratory, Hitachi Ltd. (72) Inventor Mitsuo Kayano             7-1-1, Omika-cho, Hitachi-shi, Ibaraki Prefecture             Inside the Hitachi Research Laboratory, Hitachi Ltd. (72) Inventor Hiroshi Sakamoto             7-1-1, Omika-cho, Hitachi-shi, Ibaraki Prefecture             Inside the Hitachi Research Laboratory, Hitachi Ltd. F term (reference) 3J028 EA21 EB07 EB13 EB37 EB62                       EB66 FA06 FB05 FC32 FC42                       FC57 FC64 GA02 HA12 HA13                       HA22 HB01 HB17 HC03 HC08                       HC18                 3J552 MA04 MA13 MA30 NA01 NB04                       PA02 PA20 PA61 RA04 RA07                       RB15 SA03 SA18 SB38 SB40                       UA03 UA08 VA02W VA32W                       VA32Y VA37Z VA65W VA74Z                       VA76Z VC03Z VD02Z

Claims (2)

[Claims] 1. A gear type transmission having a main clutch for transmitting power of an engine to an input shaft, a plurality of gears capable of transmitting torque from the input shaft to an output shaft, and a plurality of meshing clutches. A torque transmission path is formed from the input shaft to the output shaft by connecting the gear and the dog clutch, and when the connection of the gear and the dog clutch is switched from the first connection to the second connection. In a control device for a gear type transmission capable of forming a torque transmission path from the input shaft to the output shaft by controlling a sub-clutch, a main clutch release detection for detecting that the main clutch is released Means, and a neutral state detecting means for detecting that the dog clutch is in a neutral state, the main clutch is released, and When serial dog clutch is in a neutral state, by controlling the sub-clutch, the control device of the gear transmission, characterized in that to reduce or increase the rotational speed of the input shaft. 2. A gear type transmission having a main clutch for transmitting engine power to an input shaft, a plurality of gears capable of transmitting torque from the input shaft to an output shaft, and a plurality of meshing clutches, A torque transmission path is formed from the input shaft to the output shaft by connecting the gear and the dog clutch, and when the connection of the gear and the dog clutch is switched from the first connection to the second connection. A control method for a gear transmission capable of forming a torque transmission path from the input shaft to the output shaft by controlling a sub-clutch, comprising detecting that the main clutch is released, When the main clutch is disengaged and the dog clutch is in the neutral state, the sub clutch is opened. By Gosuru method of controlling a gear transmission, wherein the reducing or increasing the rotational speed of the input shaft.