JPH1076870A - Controller of automatic transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress wear of an automatic friction clutch during shift by providing a predetermined condition judging means which judges whether a vehicle satisfies a predetermined condition or not when shift is done and an engaging shift control means which performs shift in a condition in which the automatic friction clutch is engaged when the vehicle satisfies the predetermined condition. SOLUTION: An electronic controller judges whether it is necessary to perform slip shift control based on a condition of a vehicle which is detected or not (step 2), half clutch control is started when it is judged that it is necessary to perform the control, and it is judged whether a vehicle satisfies a predetermined condition or not when a predetermined period of time elapses (step 5). If it is judged that at least one condition of the predetermined conditions is satisfied, engaging pressure of an automatic friction clutch is increased rapidly and returns to the original engaging condition. Thus, a clutch which sets shift stage in a condition in which the automatic friction clutch is engaged is engaged and released to perform shift (step 6). Consequently, it is possible to suppress the deterioration of the automatic friction clutch due to its wear and improve the running performance and durability.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic transmission having a driving force source and a stepped transmission mechanism, and an automatic friction clutch that releases torque transmission between the driving force source and the stepped transmission mechanism. Related to the control device.

[0002]

2. Description of the Related Art Conventionally, a stepped transmission mechanism arranged on the output side of a driving force source, a friction engagement device for switching a torque transmission path of the stepped transmission mechanism to execute a shift, and a drive by release. There has been proposed a control device for an automatic transmission including an automatic friction clutch that interrupts torque transmission between a power source and a stepped transmission mechanism. In this automatic transmission control device, the shift stage is switched by engaging / disengaging the friction engagement device in a state where the automatic friction clutch is released, and thereafter the automatic friction clutch is engaged to complete the shift. I do.

That is, in the control device for the automatic transmission,
Each time a shift is performed, the automatic friction clutch is engaged and released. For this reason, there is a problem that the torque is not transmitted to the wheels during the gear shift, the driving force becomes insufficient, and the time required from the start to the end of the gear shift becomes long.

[0004] An example of a control device for an automatic transmission which solves this problem is described in Japanese Patent Application Laid-open No. Hei 2-6235. The control device for an automatic transmission described in this publication includes a friction clutch, a gear transmission connected to the friction clutch, a first actuator and a second actuator for driving the friction clutch and the gear transmission, respectively. An actuator. Further, the control device for the automatic transmission includes a first clutch that shifts the friction clutch to a half-clutch state.
A first control means for controlling the actuator and a second control means for controlling the second actuator so as to shift the gear of the gear transmission are provided.

According to the control device for an automatic transmission, the friction clutch is engaged during the setting of the shift speed, and the friction clutch is brought into a half-clutch state in response to a shift command. In this half-clutch state, after the gear of the gear transmission is shifted to the target gear position according to the shift command, the friction clutch is engaged.
That is, since the gear shift is performed while the friction clutch is in the half-clutch state, it is possible to suppress a shortage of the driving force during the shift, and to shorten the time required from the start to the end of the shift.

[0006]

However, in the control device of the automatic transmission described in the above publication, the shift is executed while the friction clutch is in the half-clutch state, so that the wear of the friction clutch is promoted. Deterioration is accelerated excessively. As a result, there is a problem that the torque transmission function is impaired, leading to a decrease in running performance and a decrease in durability.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a control device for an automatic transmission capable of suppressing abrasion of an automatic friction clutch during shifting and improving running performance and durability. It is an object.

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a stepped speed change mechanism arranged on the output side of a driving force source and a torque transmission path of the stepped speed change mechanism. A shift control is performed in a control device for an automatic transmission including a friction engagement device that performs switching by performing a shift and an automatic friction clutch that releases torque transmission between the driving force source and the stepped transmission mechanism when released. A predetermined condition determining means for determining whether or not the vehicle is under a predetermined condition, and performing a shift with the automatic friction clutch engaged when it is determined that the predetermined condition is satisfied. And a shift control means.

The predetermined conditions of the vehicle according to the present invention include: when the vehicle turns a corner; when an engine braking force is required; when a manual shift operation is performed; when sudden acceleration is required; For example, a case where the wear amount of the friction clutch reaches a predetermined value can be exemplified.

According to the present invention, when it is determined that the vehicle is in the predetermined condition, the friction engagement device is engaged / disengaged in a state where the automatic friction clutch is engaged, and the shift is executed.
Therefore, deterioration due to wear of the automatic friction clutch is suppressed, and the torque transmission function of the automatic friction clutch is maintained, so that traveling performance and durability are improved.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described based on an embodiment shown in the drawings. FIG. 2 is a sectional view showing a configuration example of the automatic transmission 1 to which the present invention is applied, and FIG. 3 is a skeleton diagram showing a schematic configuration of the automatic transmission 1. The automatic transmission 1 has a clutch housing 2 and a gear unit case 3 which are integrally formed, and an open end of the gear unit case 3 is fixed to an engine 4 as a driving force source.

As the engine 4, an internal combustion engine, an electric motor, a fuel cell system, or the like is used. Specific examples of internal combustion engines include gasoline engines, diesel engines, and LPs.
Examples include a G engine, a gas turbine engine, and a jet engine. In this embodiment, a gasoline engine is used. An input shaft 5 and a counter shaft 6 that are parallel to each other are disposed in the gear unit case 3, and one end of the input shaft 5 is inserted into the clutch housing 2.

A partition 7 is provided between the clutch housing 2 and the gear unit case 3, while a partition 8 is provided in the clutch housing 2. The input shaft 5 is rotatably held by bearings 9 and 10 separately provided at positions facing the partition 6 and the partition 7. Further, the counter shaft 6 is rotatably held by bearings 11 and 12 separately provided at positions facing the partition 6 and the partition 7.

An input automatic friction clutch 13 is provided at one end of the input shaft 5, specifically, inside the clutch housing 2. Hereinafter, the automatic friction clutch 13 will be described in detail.

A hollow clutch casing 14 mounted to be rotatable relative to the input shaft 5 includes a sleeve 14 mounted on the outer periphery of the input shaft 5, a flange 16 projecting from one end of the sleeve 15 to the outer periphery, A cylindrical portion 17 protruding from the outer peripheral end of the flange 16 toward the engine 4
And an annular cover 18 attached to an opening end of the cylindrical portion 17 on the engine 4 side.

The inner peripheral surface of the annular cover 18 is fixed to the outer periphery of an annular cylinder 19 having a substantially U-shaped cross section. The input shaft 5 is rotatably inserted into the inner periphery of the cylinder 19. ing. A disk-shaped plate 20 is fixed to a side surface of the cylinder 19 on the engine 4 side.

On the other hand, a drive plate 23 is fixed to an end of a crankshaft 21 provided on the engine 4 side, specifically, an end on the side of the automatic transmission 1 using screws 22. The drive plate 23 is connected to the plate 20 using screws 24. A clutch disk 25 is provided inside the clutch casing 14.

The clutch disk 25 includes a hub 26 spline-coupled to the outer periphery of the input shaft 5, a damper mechanism 27 provided on the outer periphery of the hub 26, and an annular plate 28 provided on the outer periphery of the hub 26. And a clutch facing 2 circumferentially fixed to both side surfaces of the plate 28.
9 is provided. A pressure receiving plate 30 is attached to the inner surface of the flange 16 of the clutch casing 14 in a circumferential direction, and the pressure receiving plate 30 and the clutch facing 29 are provided.
Are opposed to each other.

Further, between the cover 18 and the clutch disk 28 inside the clutch casing 14,
An annular pusher plate 31 is arranged movably in the axial direction of the input shaft 5.

The pusher plate 31 is arranged concentrically with the clutch casing 14, and a projection 32 is formed on a side surface of the pusher plate 31 on the cover 18 side. An annular diaphragm spring 33 is disposed between the pusher plate 31 and the cover 18. The diaphragm spring 33 has its outer peripheral side fixed to the clutch casing 14 and its inner diameter is set smaller than the outer diameter of the cylinder 19.
The diaphragm spring 33 is an annular leaf spring member whose outer peripheral portion and central portion are displaced in the axial direction of the input shaft 5.

A projection 32 of the pusher plate 31 is in contact with the diaphragm spring 33, and the inner periphery of the diaphragm spring 33 is
4 abuts. The piston 34 is arranged in the cylinder 19 and is configured to be movable in the axial direction of the input shaft 5. A hydraulic chamber 35 is formed between the piston 34 and the cylinder 19.

The oil passage 3 formed inside the input shaft 5
When the hydraulic pressure is supplied to the hydraulic chamber 35 through 6, the piston 34 moves to the left in FIG. 2 and presses the inner peripheral portion of the diaphragm spring 33 in the axial direction of the input shaft 5. Therefore, by controlling the hydraulic pressure supplied to the hydraulic chamber 35, the clutch facing 29 and the pressure receiving plate 30 are controlled.
In addition to engaging and releasing with the pusher plate 31, the engagement pressure, that is, the torque capacity can be controlled.

A hydraulic pump 37 is mounted on a side surface of the partition 7 on the side of the automatic friction clutch 13. The sleeve 15 of the clutch casing 14
Is inserted inside the hydraulic pump 37 along the outer peripheral surface of the input shaft 5, and the movable portion of the hydraulic pump 37
The ends of the sleeve 15 are connected. Therefore, the hydraulic pump 37 is driven by the rotation of the clutch casing 14.

Between the input shaft 5 and the counter shaft 6,
A stepped transmission mechanism, specifically, five gear pairs meshed with each other is provided. To describe these gear pairs in order, on the outer periphery of the intermediate portion in the axial direction of the input shaft 5,
A first speed drive gear 38 is formed.
A first speed driven gear 39 meshing with the speed drive gear 38 is rotatably mounted on the outer periphery of the counter shaft 6.

That is, a one-way clutch 40 is rotatably mounted on the outer periphery of the counter shaft 6, and
A part on the inner peripheral side of the speed driven gear 39 forms an outer race of the one-way clutch 40. The one-way clutch 40 is set so as to engage in a direction in which torque is transmitted from the first speed driven gear 39 toward the inner race 41.

A clutch hub 42 is spline-fitted to the counter shaft 6 adjacent to the one-way clutch 40, and a part of the inner race 41 of the one-way clutch 40 has an outer diameter equal to that of the clutch hub 42. It extends to the outer peripheral side so as to match. A spline (not shown) is formed on the outer peripheral surface of the clutch hub 42 and the inner race 41, and a hub sleeve 43 is fitted to the spline portion so as to be movable in the axial direction of the counter shaft 6. .
That is, the hub sleeve 43 is configured to transmit torque between the clutch hub 42 and the inner race 41 by spline-fitting the clutch hub 42 and the inner race 41.

Automatic friction clutch 1 on input shaft 5
A second-speed drive gear 44 is rotatably fitted to the end opposite to the third gear. A second-speed driven gear 45 meshing with the second-speed drive gear 44 includes a counter. The shaft 6 is spline-fitted to the outer periphery. Also,
At a position adjacent to the second speed drive gear 44, a second speed clutch 46 as a friction engagement device is provided.

The second speed clutch 46 is a wet multi-plate clutch, and has an annular clutch hub 48 in which a plurality of annular clutch disks 47 are spline-fitted to the outer peripheral portion.
Are connected to the second speed drive gear 44. Further, a clutch drum 50 in which a plurality of annular clutch plates 49 are spline-fitted to the inner peripheral surface of the cylindrical portion is spline-fitted to the end of the input shaft 5. The piston 51 is arranged inside the clutch drum 50 so as to be movable in the axial direction of the input shaft 5.

The oil passage 5 formed inside the input shaft 5
When hydraulic pressure is supplied from 3 to the hydraulic chamber 52 on the back side of the piston 51, the piston 51 moves rightward in FIG. 2 and the clutch disc 47 and the clutch plate 49 are engaged.
Torque is transmitted by the frictional force. The hydraulic chamber 5
2 is released, the return spring 54
The piston 51 is pressed to the left side in FIG. 2 by this, and the clutch disk 47 and the clutch plate 49 are released. Therefore, by adjusting the hydraulic pressure supplied to the hydraulic chamber 52, the engagement force between the clutch disk 47 and the clutch plate 49, that is, the torque capacity of the second speed clutch 46 is controlled.

A third speed drive gear 55 is rotatably held on the input shaft 5 adjacent to the first speed drive gear 38. The third speed driven gear 56 meshing with the third speed drive gear 55 is spline-fitted to the outer peripheral portion of the counter shaft 6. A third speed clutch 57 is provided adjacent to the third speed drive gear 56 as a frictional engagement device for selectively connecting the third speed drive gear 56 to the input shaft 5.

The third speed clutch 57 is a wet multi-plate clutch, and has an annular clutch hub 59 in which a plurality of annular clutch disks 58 are spline-fitted to the outer peripheral portion.
Are provided integrally with the third speed drive gear 55. A clutch drum 61 in which a plurality of annular clutch plates 60 are spline-fitted to the inner peripheral surface of the cylindrical portion.
Are spline-fitted to the input shaft 5.

The piston 62 is connected to the clutch drum 6
1 is arranged so as to be movable in the axial direction of the input shaft 5. Therefore, the oil passage 6 formed inside the input shaft 5
When hydraulic pressure is supplied from 4 to the hydraulic chamber 63 on the rear side of the piston 62, the piston 62 moves rightward in FIG. 2 to engage the clutch disc 58 and the clutch plate 60,
Torque is transmitted by the frictional force.

When the hydraulic pressure in the hydraulic chamber 62 is released, the piston 62 is pressed to the left side in FIG. 2 by the return spring 65, and the clutch disk 58 and the clutch plate 60 are released. Therefore, the hydraulic chamber 62
By adjusting the oil pressure supplied to the clutch disk 58, the engagement force between the clutch disk 58 and the clutch plate 60,
The torque capacity of the speed clutch 57 is controlled.

In the vicinity of the partition 7 on the input shaft 5,
The fourth speed drive gear 66 is spline-fitted. The fourth gear meshing with the fourth speed drive gear 66
The speed driven gear 67 is rotatably held on the outer periphery of the counter shaft 6. As a frictional engagement device for selectively connecting the fourth speed driven gear 67 to the counter shaft 6, a fourth speed clutch 68 is disposed adjacent to the fourth speed driven gear 67.

The fourth speed clutch 68 is a wet multi-plate clutch, and has an annular clutch hub 70 in which a plurality of annular clutch disks 69 are spline-fitted to the outer peripheral portion.
Are spline-fitted to the fourth speed driven gear 67. A clutch drum 7 in which a plurality of annular clutch plates 71 are spline-fitted to the inner peripheral surface of the cylindrical portion.
2 is spline-fitted to the input shaft 5.

The piston 73 is connected to the clutch drum 7
2, the input shaft 5 is disposed so as to be movable in the axial direction of the input shaft 5. Accordingly, when oil pressure is supplied from an oil passage 75 formed inside the counter shaft 6 to a hydraulic chamber 74 on the rear side of the piston 73, the piston 73 moves to the left in FIG. It is engaged, and the torque is transmitted by the frictional force.

When the hydraulic pressure in the hydraulic chamber 74 is released, the piston 73 is pressed rightward in FIG. 2 by the return spring 76, and the clutch disc 69 and the clutch plate 71 are released. Therefore, the hydraulic chamber 74
By adjusting the oil pressure supplied to the clutch disk 69 and the clutch plate 71,
The torque capacity of the speed clutch 68 is controlled.

Third speed clutch 5 on the input shaft 5
A fifth speed drive gear 77 is spline-fitted between 7 and the partition wall 8. The fifth speed driven gear 78 meshing with the fifth speed drive gear 77 is rotatably held by the counter shaft 6. A fifth speed clutch 79 as a friction engagement device for selectively connecting the fifth speed driven gear 78 to the counter shaft 6 is disposed between the partition wall 8 and the fifth speed driven gear 78. .

The fifth speed clutch 79 is a wet multi-plate clutch, and has an annular clutch hub 81 in which a plurality of annular clutch disks 80 are spline-fitted to the outer peripheral portion.
Are spline-fitted to the fifth speed drive gear 78. A clutch drum 8 in which a plurality of annular clutch plates 82 are spline-fitted to the inner peripheral surface of the cylindrical portion.
3 is spline-fitted to the counter 6.

The piston 84 is connected to the clutch drum 8
3, it is arranged so as to be movable in the axial direction of the counter shaft 6. Accordingly, when oil pressure is supplied from an oil passage 86 formed inside the counter shaft 6 to a hydraulic chamber 85 on the rear side of the piston 84, the piston 84 moves rightward in FIG. It is engaged, and the torque is transmitted by the frictional force.

When the hydraulic pressure in the hydraulic chamber 85 is released, the piston 84 is pressed to the left in FIG. 2 by the return spring 87, and the clutch disc 80 and the clutch plate 82 are released. Therefore, the hydraulic chamber 85
By adjusting the hydraulic pressure supplied to the clutch disk 80, the engagement force between the clutch disc 80 and the clutch plate 82,
The torque capacity of the speed clutch 79 is controlled.

A description will be given of the reverse gear pair. Between the clutch hub 42 spline-fitted to the counter shaft 6 and the fourth speed driven gear 67, a reverse driven gear 88 is provided with respect to the counter shaft 6. It is arranged rotatably. The outer diameter of the portion of the reverse driven gear 88 that contacts the clutch hub 42 is
, And a spline is formed on the outer peripheral surface thereof. Therefore, the clutch hub 42 and the reverse driven gear 67 are connected so that torque can be transmitted by the operation of the hub sleeve 43.

A reverse shaft (not shown) is rotatably provided in the gear casing 3 in parallel with the input shaft 5 and the counter shaft 6, and the reverse shaft is provided with, for example, a first speed drive gear. A gear (not shown) meshed with 38 and a reverse drive gear (not shown) meshed with the reverse driven gear 88 are attached.
Therefore, the clutch hub 4 is formed by the hub sleeve 43.
2 and the reverse driven gear 67,
The reverse gear is set.

A drive gear 89 is formed at one end of the counter shaft 6, and a ring gear 91 attached to the differential carrier 90 meshes with the drive gear 89. Further, inside the differential carrier 90, the differential carrier 9 is provided.
A pinion shaft 92 that rotates integrally with the pinion 0 is provided, and a pair of pinion gears 93 are rotatably attached to the pinion shaft 92. A pair of side gears 94 mesh with the pair of pinion gears 93, and a drive shaft 95 is connected to each of the pair of side gears 94. A wheel, for example, a front wheel (not shown) is attached to an end of the drive shaft 95.

FIG. 4 is a block diagram showing a control system of the automatic transmission 1 having the above configuration. The electronic control unit 96 determines the state of the vehicle, and based on the determination result, determines whether the automatic transmission 1
And a central processing unit (CP
U), a storage device (RAM, ROM), and a microcomputer mainly including an input / output interface.

The electronic control unit 96 includes, as data for judging the state of the vehicle, an engine speed, in other words, a signal of an input speed sensor 97 for detecting the input speed of the automatic friction clutch 13, an automatic friction clutch, 13, a signal from an output speed sensor 98 for detecting the output speed of the motor 13, a signal from a vehicle speed sensor 99,
Sensor 1 for detecting the signal of the pressure sensor 100 for detecting the hydraulic pressure acting on the engine, the amount and speed of depression of the accelerator pedal, and the throttle opening of the engine 4
01, acceleration sensor 10 for detecting vehicle acceleration
2, a signal from a manual shift switch 103 for detecting a manual shift operation performed by the driver, a signal from a steering angle sensor 104 for detecting a steering angle, and a wear amount of the clutch facing 29 constituting the automatic friction clutch 13 are detected. Wear detection sensor 104A
Is input.

The electronic control unit 96 stores a shift pattern (shift map) for controlling the automatic transmission 1 in accordance with various running modes. Further, the electronic control unit 96 includes an engagement pressure of each clutch for achieving each shift speed, a duty ratio of the linear solenoid valves 111, 112, 113, and 114 for achieving the engagement pressure, and an automatic friction. The target value of the engagement pressure when the clutch 13 is slipped, the duty ratio of the linear solenoid valve 115 according to the target value, the automatic friction clutch 13
Is stored. Further, a timer built in the electronic control unit 96 is set with a predetermined time used for performing the engagement shift control described later.

Then, a control signal is output from the electronic control unit 96 to the hydraulic control unit 105. The hydraulic control device 105 controls the operations of the clutches 46, 57, 68, 79 for setting the shift speed of the automatic transmission 1 and the operation of the automatic friction clutch 13. That is, a control signal is output to the hydraulic control device 105 based on a manual shift operation or a vehicle state to execute a shift.

FIG. 5 is a hydraulic circuit diagram showing a schematic configuration of the hydraulic control device 105. The oil in the automatic transmission 1 (so-called automatic transmission fluid) is transported by an oil pump 37, and a part of the oil is
107, 108, 109 and 110.

Each pressure regulating valve 106, 107, 108, 10
Reference numerals 9 and 110 each have a well-known structure including a control port, an output port, a spool, a spring, and the like. Each control port of the pressure regulating valves 106, 107, 108, 109, and 110 has a well-known structure. The provided linear solenoid valves 111, 112, 113, 114 and 115 are separately connected. Linear solenoid valve 111,
The electronic control unit 96 controls ON / OFF of 112, 113, 114 and 115 separately, and controls the duty ratios of the linear solenoid valves 111, 112, 113, 114 and 115 to control the pressure regulating valves 106, 107 and 1 respectively.
The line pressure output from the output ports 08, 109, and 110 is regulated.

The pressure regulating valves 106, 107, 108, 1
09 are shift valves 116, 117, 1
18 and 119, and the output port of the pressure regulating valve 110 is connected to the automatic friction clutch valve 120. Solenoid valves 121, 122, 123, 124, and 125 are separately connected to the shift valves 116, 117, 118, 119 and the automatic friction clutch valve 120.

The solenoid valves 121, 122, 123,
The solenoid valves 124 and 125 are separately controlled according to the driver's manual shift operation or the vehicle state.
The output ports (not shown) of the shift valves 116, 117, 118, and 119 and the automatic friction clutch valve 1 are turned on and off by the switches 21, 122, 123, 124, and 125.
20 output ports (not shown) are opened and closed. Further, shift valves 116, 117, 11
8, 119 output ports are hydraulic chambers 52, 63, 74, 8
5 and an output port of the automatic friction clutch valve 120 is connected to the hydraulic chamber 35.

The hydraulic control device 10 configured as described above
5, if the line pressure is separately supplied and released to the hydraulic chambers 52, 63, 74, 85, the clutches 46, 5
7, 68, 74 are engaged / disengaged, and the shift is executed.
When performing this shift, the pressure regulating valves 106, 107, 1
08, 109, if the line pressure supplied to the hydraulic chambers 52, 63, 74, 85 is separately adjusted, each clutch 4
The engagement pressures of 6, 57, 68 and 74, that is, the torque capacities can be controlled separately.

In a transitional stage during the gear shift, the torque capacity of the clutch that sets the gear before the change is determined by:
The shift valves 116, 117, 118, and so on can prevent a so-called tie-up state in which the torque capacity of the clutch that sets the changed gear position is both equal to or greater than a predetermined value.
The opening / closing timing of 119 is controlled by the electronic control unit 96.

Further, by adjusting the line pressure supplied to the automatic friction clutch valve 120 while the vehicle is running, the engagement pressure of the automatic friction clutch 13, that is, the torque capacity can be controlled. The hub sleeve 43 for setting the first forward speed or the reverse speed is moved in the axial direction of the counter shaft 6 by an actuator (not shown) controlled by the electronic control unit 96.

Next, the operation of the above embodiment will be described. In the neutral state, the hydraulic chamber 35 of the automatic friction clutch 13
Release the hydraulic pressure supplied to. Then, the center portion of the diaphragm spring 33 contacts the side surface of the cylinder 19 by its elastic force, and the pusher plate 31 contacting the diaphragm spring 16 moves rightward in FIG. Cancel. That is, the automatic friction clutch 13 is released, the output torque of the engine 4 is cut off by the clutch casing 14, and is not transmitted to the input shaft 5.

On the other hand, in order to set the forward first speed, the hydraulic pressure supplied to each of the hydraulic chambers 52, 63, 74, 85 is released to release the clutches 46, 57, 68,
While releasing 79, the hub sleeve 43 is moved to the position shown by the solid line in FIG. 2 to connect the clutch hub 42 and the inner race 41 of the one-way clutch 40.
Then, in this state, the hydraulic chamber 35 of the automatic friction clutch 13
2 to move the piston 34 to the left in FIG. 2, thereby pressing the center portion of the diaphragm spring 33 to the left in FIG.

As a result, the diaphragm spring 33
However, since the central portion is displaced toward the damper mechanism 27 in the axial direction of the input shaft 5 with the outer peripheral side as a fulcrum, the pusher plate 31 is pushed toward the pressure receiving plate 30, and the pusher plate 31 and the pressure receiving plate 30 Clutch facing 29
Into an engaged state. Then, the output torque of the crankshaft 31 of the engine 4 is transmitted to the input shaft 5 via the clutch casing 14, the clutch disc 25, and the clutch hub 26.

The torque transmitted to the input shaft 5 is transmitted from the first-speed drive gear 38 to the first-speed driven gear 39, and the first-speed driven gear 39 rotates forward. The one-way clutch 40 arranged on the inner peripheral side of the first-speed driven gear 39 is set so as to engage in a direction in which torque is transmitted from the first-speed driven gear 39 toward the counter shaft 6. Therefore, the one-way clutch 40 is engaged by the rotation of the input shaft 5 as described above.

The one-way clutch 40 is connected to the counter shaft 6 via the hub sleeve 43 and the clutch hub 42 as described above. Speed drive gear 38,
The torque is transmitted via the first speed driven gear 39. The gear ratio in this case is the first speed drive gear 38,
The first speed driven gear 39 is determined based on the gear ratio, and the forward first speed is established. The torque transmitted to the counter shaft 6 is transmitted to the differential carrier 90 via the drive gear 89 and the ring gear 91, and also transmitted to the drive shaft 95 via the pinion gear 93 and the side gear 94, so that the wheels are driven and the vehicle travels. .

When starting the vehicle, the hydraulic chamber 35
By controlling the hydraulic pressure supplied to the automatic friction clutch 13 so that the pressure gradually increases, the automatic friction clutch 13
, The torque capacity of the vehicle is gradually increased, the driving force of the vehicle gradually increases, and a smooth start can be performed.

The second forward speed is the second speed clutch 4
6 is engaged. When the second speed clutch 46 is engaged, the second speed drive gear 44 is connected to the input shaft 5, and the torque of the input shaft 5 is transmitted via the second speed drive gear 44 and the second speed driven gear 45. And transmitted to the counter shaft 6.

The gear ratio between the second speed drive gear 44 and the second speed driven gear 45 is the first speed drive gear 38.
Since the gear ratio is smaller than that of the driven gear 39 for the first speed, the counter shaft 6 rotates at a higher speed than in the case of the first speed, and the second forward speed is set. Therefore, in this case, since the counter shaft 6 rotates at a higher speed than the driven gear 39 for the first speed, the one-way clutch 40 is disengaged, and the shift from the first speed to the second speed is performed in the second speed. This is achieved by switching only the clutch 46 from the released state to the engaged state.

The third to fifth speeds are set by engaging the clutches 57, 68, and 79 provided corresponding to the respective gears, as in the case of the above-described second speed. That is, the drive gear and the driven gear at each speed are always meshed with each other, but one of the gears is rotatable with respect to the shaft holding the gear, and is selectively connected to the shaft by a clutch. With such a configuration, by engaging the clutch, torque is transmitted by a gear pair corresponding to the clutch, and a gear position by the gear pair is set.

The reverse gear will be described. In the reverse gear, the hub sleeve 43 is moved to the right in FIG. 2 to connect the clutch hub 42 and the driven gear 80 for reverse.
In this state, the automatic friction clutch 13 is engaged. Therefore, the torque is transmitted from the input shaft 5 to the reverse driven gear 80 via the reverse shaft (not shown), so that the counter shaft 6 rotates in the direction opposite to the case of the forward gear, and as a result, the reverse gear is set. Is done.

When shifting is performed by the automatic transmission 1, any one of engagement shift control, slip shift control, and engagement / disengagement shift control is selected based on the vehicle state. In this embodiment, the engagement shift control is performed when the vehicle is under the predetermined condition, and the slip control or the engagement / disengagement control is performed when the vehicle is not under the predetermined condition.

The above-mentioned engagement speed change control means that the clutch for setting the speed is engaged while the automatic friction clutch 13 is engaged.
This is control for releasing the gears and executing the gear shifting. When the engagement shift control is performed, it is difficult to suppress the shift shock, but a reduction in the driving force during the shift is suppressed, and
Responsiveness is improved.

The slip shift control means that after the engagement pressure of the automatic friction clutch 13 is reduced and slippage is performed, the clutch for setting the shift speed is engaged and released, and then the automatic clutch 13 is engaged. To end the shift. When the slip control is performed, the shift shock can be reduced.

Further, the engagement / release shift control is to release the automatic friction clutch 13 once, to engage / disengage the clutch for setting the shift speed, and then to engage the automatic friction clutch 13. When the engagement / release shift control is performed, the responsiveness and the driving force are reduced, but the shift shock can be sufficiently suppressed.

As described above, the characteristics of each shift control are different.
The predetermined conditions for which it is desirable to select the engagement shift control include, specifically, when the vehicle turns a corner, when engine braking force is required, when a manual shift operation is performed, and when sudden acceleration is required. In this case, the wear amount of the automatic friction clutch 13 reaches a predetermined value. In other words, in these traveling states, the improvement of the driving force and the responsiveness or the intention of the driver is emphasized.

Shift shocks are suppressed in vehicle conditions other than the predetermined conditions, for example, when shifting straight ahead, when making a manual shift error, when making a manual shift from the neutral range to the drive range, when a muffled sound is generated, or when operating the accelerator pedal incorrectly. For slip shifting control or engagement
Release shift control is applied.

FIG. 1 is a flowchart showing an example of a control routine combining the slip shift control and the engagement shift control, and FIG. 6 is a time chart showing the state of the system during the control routine of FIG. First, as described above, the data necessary for the shift control is detected by the electronic control unit 96 (step 1). Then, the electronic control unit 96 determines whether or not it is necessary to perform the slip shift control based on the detected state of the vehicle (step 2).

If an affirmative determination is made in step 2, the following slip shift control, in other words, half-clutch control is started. First, based on a map f stored in the electronic control unit 96, a target value Nref of the engagement pressure of the automatic friction clutch 13 is set so as to be suitable for the vehicle state, and the linear solenoid valve 1 is set in accordance with the target value Nref.
A duty ratio of 10 is controlled.

As a result, the hydraulic pressure acting on the piston 34 decreases, and the input rotation speed Nin and the output speed start when the engagement pressure of the automatic friction clutch 13 becomes smaller than the engagement pressure at which the torque of the crankshaft 21 can be transmitted. There is a difference from the rotation speed Nout. This difference is the slip amount ΔN of the automatic friction clutch 13. Then, the deviation value Ndif is calculated by subtracting the slip amount ΔN from the target value Nref (step 3).

Next, a duty ratio Dsig such that the engagement pressure of the automatic friction clutch 13 becomes the target value Nref is calculated based on the deviation value Ndif, and the linear solenoid valve 115 is controlled by the duty ratio Dsig ( Step 4). As a result, the hydraulic pressure acting on the piston 34 is controlled, the slip amount of the automatic friction clutch 13 becomes constant, and the input rotation speed Nin and the output rotation speed Nout
Are controlled to a constant value.

When a predetermined time has elapsed since the start of the half-clutch control of the automatic friction clutch 13, it is determined whether or not there is an interrupt command for inhibiting the half-clutch control, that is, whether or not the vehicle state is under a predetermined condition ( Step 5). This step 5 corresponds to the running state determination means of the present invention.

In step 5, for example, it is determined based on a signal from the steering angle sensor 104 whether or not the vehicle is turning a corner. Also, the engine speed detected by the input speed sensor 97 and the vehicle speed sensor 9
It is determined whether an engine braking force is required based on the vehicle speed detected by the acceleration sensor 9, the acceleration sensor detected by the acceleration sensor 102, the throttle opening detected by the throttle sensor 101, and the like. Further, based on a signal from the manual shift switch 103, it is determined whether or not a manual shift operation has been performed. Furthermore, it is determined based on a signal from the throttle sensor 101 whether rapid acceleration is required.

If it is determined in step 5 that there is at least one of the predetermined conditions, the linear solenoid valve 11
The duty ratio Dsig of 5 is the maximum value h (oil pressure Pmax)
As shown in FIG. 6, the hydraulic pressure acting on the piston 34 reaches the maximum value. As a result, the automatic friction clutch 13
Is rapidly increased to return to the original engagement state, and the input rotation speed Nin and the output rotation speed Nout match.

In this way, the clutch for setting the gear position is engaged / disengaged with the automatic friction clutch 13 engaged, and the gear shift is executed (step 6). Therefore,
Deterioration due to wear of the automatic friction clutch 13 is suppressed, and the torque transmission function of the automatic friction clutch 13 is maintained, so that traveling performance is improved and durability is improved.

If the control of step 6 is performed when the vehicle turns a corner, a decrease in the torque transmitted to the wheels during shifting is suppressed. Therefore, a sufficient driving force is obtained according to the running resistance, and the running performance is improved.

If the control of step 6 is performed when the engine braking force is required, the engine 4
Up to the power transmission device is maintained in the connected state. Therefore, it is possible to suppress a decrease in the engine braking force during the shifting, and to obtain an engine braking force that is not excessive or insufficient according to the gradient of the road.

Further, if the control of step 6 is performed during the manual shift operation, the time required from the start to the end of the shift is shortened in any case of the upshift or the downshift, and the transmission to the wheels during the shift is performed. Decrease in the applied torque can be suppressed. Therefore, a shift with good responsiveness can be performed based on the driver's intention, and traveling performance is improved.

Further, if the control of step 6 is performed when rapid acceleration is required, the time required from the start to the end of the shift can be reduced, and the torque transmitted to the wheels during the shift can be reduced. Since the acceleration can be suppressed, the acceleration performance is improved. Further, if the control of step 6 is performed when the wear amount of the automatic friction clutch 13 has reached a predetermined value, the wear of the automatic friction clutch 13 can be suppressed to a predetermined value or more. Is done. Therefore, the torque transmission function and durability of the automatic friction clutch 13 can be maintained.

After the shift has been executed as described above, the prohibition interrupt command is canceled after a predetermined time has elapsed after it is determined that the prohibition interrupt command has been issued (step 7), and this control routine is terminated. The predetermined time used in step 7 is set longer than the time required for engaging and disengaging the clutch for setting the shift speed. Steps 6 and 7 correspond to the engagement shift control means of the present invention.

On the other hand, if a negative determination is made in step 5, automatic determination is made based on whether the preset value ε of the engagement pressure exceeds the deviation value Ndif and whether the preset value ε is substantially zero. It is determined whether the slip amount of the friction clutch 13 has reached the target value Nref (step 8).

If a positive determination is made in step 8, the clutch for setting the shift speed is engaged / disengaged and the shift is executed (step 9). Thereafter, the hydraulic pressure acting on the piston 34 is increased as shown by the broken line in FIG. 6, and the input rotation speed Nin and the output rotation speed Nout are changed as shown by the broken line. Then, when the engagement pressure of the automatic friction clutch 13 reaches a predetermined value and the input rotational speed Nin and the output rotational speed Nout match, the gear shift ends, and this control routine ends. If a negative determination is made in step 8, the process returns to step 3, and if a negative determination is made in step 2, the control routine ends.

In the above embodiment, the prohibition control may be released after a predetermined time after the determination of the prohibition interrupt command is released in step 9. Such control can be performed by setting a fixed time in a timer built in the electronic control unit 96. By performing this control, when the predetermined condition is reached again within a certain time after the determination of the prohibition interrupt command is canceled, the shift corresponding to the predetermined condition can be executed quickly, and the traveling performance is further improved.

In the present invention, the automatic friction clutch 1
It is also possible to determine whether or not the traveling state is under a predetermined condition before starting the slip control of No. 3 and to execute the engagement shift control as it is when the predetermined condition is satisfied. By performing this control, the half-clutch control of the automatic friction clutch 13 is omitted, so that the time required from the start to the end of the shift is further reduced, and the responsiveness is further improved.

[0089]

As described above, according to the present invention, when the predetermined condition determining means determines that the vehicle state is under the predetermined condition, the frictional engagement is performed with the automatic friction clutch engaged. The device is engaged / disengaged, and a shift is executed. Therefore, deterioration due to wear of the automatic friction clutch is suppressed, and the torque transmission function of the automatic friction clutch is maintained, so that traveling performance and durability are improved.

[Brief description of the drawings]

FIG. 1 is a flowchart illustrating an example of a control routine according to the present invention.

FIG. 2 is a schematic sectional view showing a configuration of an automatic transmission and an automatic friction clutch used in the present invention.

FIG. 3 is a skeleton diagram of the automatic transmission and the automatic friction clutch of FIG. 2;

4 is a block diagram showing a control system of the automatic transmission shown in FIG.

FIG. 5 is a block diagram showing a schematic configuration of a hydraulic control device applied to the automatic transmission shown in FIG. 2;

FIG. 6 is a time chart showing the state of the system when the control routine shown in FIG. 1 is executed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Automatic transmission 4 Engine (drive power source) 5 Input shaft 6 Counter shaft 13 Automatic friction clutch

Claims (1)

[Claims] 1. A stepped transmission mechanism disposed on an output side of a driving force source, a friction engagement device that switches a torque transmission path of the stepped transmission mechanism to execute a shift, and releases the driving force by releasing. A control device for an automatic transmission including a power source and an automatic friction clutch that interrupts torque transmission between the stepped transmission mechanism and a predetermined condition for determining whether or not the vehicle is under a predetermined condition when performing a shift. An automatic transmission, comprising: a determination unit; and an engagement shift control unit that executes a shift in a state where the automatic friction clutch is engaged when it is determined that the predetermined condition is satisfied. Control device.