JP3345440B2 - Control device for automatic transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an automatic transmission mounted on an automobile, and more particularly to a control device for an automatic transmission in which a friction element for engine braking is engaged at a predetermined gear.

[0002]

2. Description of the Related Art A torque converter and a speed change mechanism are connected to each other, and the power transmission path of the speed change mechanism is switched by selectively engaging a plurality of friction elements to automatically shift to a speed most suitable for an operation state. In the automatic transmission configured as described above, in order to improve the engine braking performance during coasting, a friction element for engine braking such as a coast brake is mainly used at a shift speed (for example, third or fourth speed) used during high-speed running. Some are designed to be fastened.

On the other hand, in recent years, in this type of automatic transmission, the number of gears has been increased in order to improve fuel efficiency and output performance.
Japanese Patent Application Laid-Open No. 5 (1999) -2005 discloses that a main transmission and a sub transmission having a transmission mechanism that operates independently of each other are connected in series, and the output of one transmission is further shifted by the other transmission to achieve multi-stage transmission. A configuration in which gear shifting is performed is shown.

[0004]

By the way, in this type of automatic transmission, for example, a preset shift pattern is compared with an actual operation state indicated by a vehicle speed, a throttle opening, and the like, and the operation state is determined as described above. A shift control for downshifting or upshifting the shift speed is performed based on a shift command output when a speed line constituting a shift pattern is exceeded. For example, a shift operation based on a downshift shift command is performed. When the accelerator pedal is released before the completion of the above, an upshift command for returning the gear position to the original gear position may be output as the engine load decreases.

[0005] In such a case, if the upshift is performed to return to the original gear after the shift operation based on the preceding downshift command is completed,
Even though the accelerator pedal is not depressed, the shift speed is temporarily down-shifted, which makes the driver feel uncomfortable.

To solve such a problem, it is conceivable to perform shift control for returning the gear to the original gear when a gear shift command for returning to the original gear is output.
An automatic transmission configured to simultaneously perform a shift operation in a main transmission and a subtransmission during a shift in which a shift speed at which a friction element for engine braking is engaged and another shift speed at which the friction element is released are switched; In the engine, a shock caused by the return of the engine brake friction element to the engaged state and a shock caused by the return of the engaged state of the other friction elements to the original gear stage are superimposed to generate a large shift shock. There is a possibility that.

[0007] In particular, when the shift speed at which the friction element for engine braking is engaged and the other shift speed at which the friction element is released are switched, the change in the gear ratio between the main transmission and the auxiliary transmission is reversed. In the automatic transmission configured to simultaneously perform the speed change operations in the two directions, the gear ratio of the auxiliary transmission changes in the opposite direction in accordance with the change in the gear ratio of the main transmission, so that the predetermined speed on the side of the auxiliary transmission is changed. If the engagement force of the friction element is controlled in a feedback manner, when a shift request for returning to the original gear stage occurs due to a decrease in the engine load during the gear shift, the frictional element for the engine brake is engaged and the main shift is performed. The gear ratio of the machine may change abnormally, which significantly complicates the shift control and may increase the shift shock.

According to the present invention, the main transmission and the auxiliary transmission are simultaneously operated at the time of a shift in which a predetermined shift speed at which a friction element for engine braking is engaged and another shift speed at which the friction element is released are switched. In an automatic transmission in which a shift operation is performed, the above-described problem is solved when a shift request to return to the predetermined shift stage due to a decrease in engine load during a shift operation is performed. The purpose is to return to the step.

[0009]

That is, a control device for an automatic transmission according to the invention of claim 1 of the present application (hereinafter referred to as a first invention) includes a main transmission having a transmission mechanism that operates independently of each other. And a sub-transmission, which is provided in the main transmission.
The main transmission is configured such that the engine brake friction element is engaged at a predetermined shift speed, and the main transmission is operated during a shift in which the predetermined shift speed and another shift speed at which the engine brake friction element is released are switched. and the automatic transmission shifting operation is carried out simultaneously in the auxiliary transmission, switching of the auxiliary transmission
Provided with a judging means for judging completion of over operation, the from a predetermined shift stage at the time of shift-down to the other gear position the engine braking friction element is released, the frictional element for the ene <br/> Jin brake When the shift request for returning the shift speed to the predetermined shift speed is generated due to a decrease in the engine load after the release operation of the main transmission and the shift operation of the subtransmission are started, the friction element for engine brake While maintaining the released state of the main transmission and the auxiliary transmission, the engagement state of the other friction elements is returned to the state of the predetermined gear position.
After that , the determination means determines the end of the switching operation of the auxiliary transmission.
In this case, a control means for starting the operation of engaging the friction element for engine braking is provided.

The invention of claim 2 of the present application (hereinafter referred to as the second invention)
The control device for an automatic transmission according to the invention is described in claim 1.
In the invention described in the above, the determining means is provided on the input side of the auxiliary transmission.
A rotation sensor that detects the number of rotations of the
Judgment based on signal from rotation sensor that detects rotation speed
It is characterized by doing .

[0011]

According to the present invention, the following effects can be obtained according to the present invention.

In other words, according to the first and second aspects of the present invention, during a shift in which a predetermined shift speed at which the friction element for engine braking is engaged is switched to another shift speed at which the friction element is disengaged, the engine is shifted during shifting. In the case where a shift request for returning to the original predetermined gear stage is caused by the decrease in load, the frictional element of the main transmission and the sub-transmission is maintained while the released state of the friction element for engine braking is maintained. Since the engaged state is restored to the state of the predetermined shift speed, the occurrence of a large shock is prevented, and the shift operation is performed satisfactorily.

[0013]

In addition, after the operation of releasing the friction element for engine braking and the operation of shifting the main and auxiliary transmissions are started,
When a shift request is issued to return the gear to the original gear at which the friction element for engine braking is engaged due to a decrease in the engine load, the release state of the friction element for engine braking is maintained in another state. Since the engaged state of the friction element is returned to the original state, the control is not complicated, and the shock is greatly reduced.

[0015]

Embodiments of the present invention will be described below.

As shown in FIG. 1, an automatic transmission 1 according to this embodiment includes a torque converter 10, a main transmission 20 arranged on the same axis as the torque converter 10, and a main transmission 20 parallel to these axes. And an auxiliary transmission 30 arranged on the axis.

The torque converter 10 includes a pump 12 integrated with a case 11 connected to the engine output shaft 2,
A turbine 13 disposed opposite to the pump 12 and driven by the pump 12 via hydraulic oil, and disposed between the pump 12 and the turbine 13 and supported by the transmission case 3 via a one-way clutch 14 Stator 1
5, a converter output shaft 16 connected to the turbine 13, and a lock-up clutch 17 that directly connects the output shaft 16 to the engine output shaft 2 via the case 11.

The torque converter 10 and the main transmission 2
Between 0 and 0, an oil pump 4 driven by the engine output shaft 2 via the torque converter 10 is arranged.

The main transmission 20 includes a converter output shaft 1
6 has a front planetary gear mechanism 21 arranged on the torque converter side and a rear planetary gear mechanism 22 arranged on the anti-torque converter side. The converter output shaft 16 is connected to the sun gear 21a of the front planetary gear mechanism 21 via the forward clutch 23 and to the sun gear 2a of the rear planetary gear mechanism 22 via the direct coupling clutch 24.
2a, the sun gear 21a of the front planetary gear mechanism 21 and the ring gear 22b of the rear planetary gear mechanism 22 are connected.

Between the ring gear 21b of the front planetary gear mechanism 21 and the transmission case 3, a first one-way clutch 25 and a low reverse brake 26 are arranged in parallel. A second one-way clutch 27 and a 3-4 brake 28 are arranged in series between the sun gear 22a and the transmission case 3, and a coast brake 29 for engine braking is arranged in parallel with the second one-way clutch 27 and the 3-4 brake 28. Then, the pinion carriers 21c, 22c of the front planetary gear mechanism 21 and the rear planetary gear mechanism 22 are connected, and the main transmission 2
An intermediate gear 5 for transmitting power from the transmission 0 to the auxiliary transmission 30 is connected.

With this configuration, the main transmission 20
According to the above, the forward clutch 23, the direct coupling clutch 24,
By selectively engaging the 3-4 brake 28 and the low reverse brake 26, a forward low speed stage, a medium speed stage, a high speed stage, and a reverse stage can be obtained.

On the other hand, the sub-transmission 30 has a single planetary gear mechanism 31, and the intermediate gear 6 always meshed with the intermediate gear 5 in the main transmission 20 is connected to the ring gear 31 a of the planetary gear mechanism 31. And the ring gear 31
A direct connection clutch 32 is disposed between the transmission gear 3 and the sun gear 31b, and a third one-way clutch 33 and a reduction brake 34 are disposed in parallel between the sun gear 31b and the transmission case 3. And, the planetary gear mechanism 31
The output gear 7 is connected to the pinion carrier 31c, and left and right driving wheels (not shown) are connected to the output gear 7 via a differential device.
Power is transmitted to the vehicle.

The auxiliary transmission 30 can shift the power input from the main transmission 20 through the intermediate gears 5 and 6 to two forward speeds, a low speed stage and a high speed stage, and output it to the output gear 7. It has become.

That is, when the direct coupling clutch 32 is released, the sun gear 31 of the planetary gear mechanism 31 is actuated by the third one-way clutch 33 or the deceleration brake 34.
When b is fixed, the power from the intermediate gear 6 input to the ring gear 31a of the planetary gear mechanism 31 is reduced and output from the pinion carrier 31c to the output gear 7, whereby a low speed stage is obtained. In this case, if the deceleration brake 34 is engaged, the auxiliary transmission 30
As a single unit, the engine brake operates.

Further, the direct coupling clutch 32 is engaged,
When the deceleration brake 34 is released, the ring gear 31a and the sun gear 31b of the planetary gear mechanism 31 are coupled to each other, so that the power from the intermediate gear 6 is directly output from the pinion carrier 31c to the output gear 7,
As a result, a high-speed stage (directly connected stage) is obtained.

In this manner, the main transmission 20 provides three forward speeds and one reverse speed, and the subtransmission 3
With 0, two high and low gear stages can be obtained with respect to the output of the main transmission 20, so that the automatic transmission as a whole has six gear stages for forward movement, and for the reverse movement, a main gear position for the reverse. The combination of the reverse gear of the engine 20 and the low gear to which the deceleration brake 34 of the auxiliary transmission 30 is engaged provides the overall reverse gear. And in this example,
As the forward gear, five predetermined gears out of the six gears are adopted.

The operating states of the clutches and brakes at each of the five forward speeds and one reverse speed are summarized in Table 1. In Table 1, (○) indicates that the vehicle is engaged only in the engine brake range.

[0028]

[Table 1] In this embodiment, as the engagement pistons of the direct coupling clutch 32 and the deceleration brake 34 in the auxiliary transmission 30,
A piston having a double structure as shown in FIG. 2 is employed.

That is, the direct coupling clutch 32 is connected to the intermediate gear 6.
A drum member 3 integrated with a hub member 32a integrally formed with a ring gear 31a of the planetary gear mechanism 31 and a shaft 35 to which a sun gear 31b of the planetary gear mechanism 31 is fixed.
2b and a plurality of friction plates 32 on the driving side and the driven side
c, 32d are alternately arranged, and these friction plates 3
A large-diameter first piston 32e having a large pressure-receiving area is disposed at the back of 2c, 32d, and a small-diameter second piston 32f having a small-pressure-receiving area is further disposed at the back thereof. The return of both pistons 32e, 32f It is configured to include a spring 32g.

[0030] Then, the first hydraulic chamber 32 ₁ of the back of the first piston 32e which coupling pressure by the oil passage 36 is introduced, a second hydraulic pressure of the back of the second piston 32f which coupling pressure by the oil passage 37 is introduced chamber 32 ₂ and is provided, when these hydraulic chambers 32 _1, 32 ₂ in the same engagement pressure is introduced, first
Who when introduced into the hydraulic chamber 32 ₁ is adapted to larger fastening force than when it is introduced into the second hydraulic chamber 32 ₂ is obtained.

The deceleration brake 34 has a plurality of drive side and driven side friction plates 34a, 34b alternately arranged between the drum member 32b of the direct coupling clutch 32 and the transmission case 3, and a return spring. these friction plates 34a against 34c, provided with a piston 34d for fastening the 34b, the back of the piston 34d, the inner circumferential side first hydraulic chamber 34 ₁ of the large pressure receiving area, a small outer periphery of the pressure receiving area It is second and the hydraulic chamber 34 ₂ of the structure provided coaxially with. When these hydraulic chambers 34 _1, 34 ₂ in the same engagement pressure is introduced, towards the case of the engagement pressure to the first hydraulic pressure chamber 34 ₁ is introduced it is introduced into the second hydraulic chamber 34 ₂ In this case, a larger fastening force can be obtained.

Next, a description will be given of a hydraulic circuit for selectively engaging each clutch and brake in accordance with Table 1 to form a shift speed according to an operating state or a driver's request.

As shown in FIG. 3, the hydraulic circuit 40 includes a regulator valve 4 for adjusting the pressure of the hydraulic oil discharged from the oil pump 4 to a predetermined line pressure.
The main line 42 controls a manual valve 43 operated by a driver, and first to third reducing valves for generating various control source pressures. 44,
45 and 46.

These reducing valves 44 to 46
Among them, the control source pressure reduced to a constant pressure by the first reducing valve 44 is supplied to the modulator valve 48 via the line 47. The control pressure adjusted by the duty solenoid valve 49 is supplied to the control port 48a of the modulator valve 48.
A modulator pressure is generated from the control source pressure in accordance with a duty ratio of 9 (a ratio of ON time during 1 ON and OFF cycles), and the modulator pressure is applied to a first pressure increase of the regulator valve 41 via a line 50. Port 4
1a, whereby the line pressure is increased in accordance with the duty ratio. In this case, by setting the duty ratio according to, for example, the throttle opening of the engine, the line pressure is adjusted to a value corresponding to the throttle opening and the like. A first accumulator 51 for suppressing a pulsation of the hydraulic pressure caused by the periodic ON / OFF operation of the duty solenoid valve 49 is provided on a line 50 for supplying to the first pressure increasing port 41a of the first 41.
Is installed.

The manual valve 43 includes D,
3, 2, 1 forward range, R (reverse) range, N
A (neutral) range and a P (parking) range can be set. In the forward range, the main line 42 is connected to the forward line 52, and in the R range, the main line 42 is connected to the reverse line 53.

The forward line 52 is guided to the forward clutch 23 through an orifice 54 having a different throttle amount between the time of supply and discharge of the hydraulic oil.
In each of the forward ranges 3, 2, and 1, the forward clutch 23 is always engaged. In this case, a second accumulator 55 for reducing a shock at the time of supplying the engagement pressure to the forward clutch 23 is installed in the forward line 52, and the second accumulator 55 is connected to the accumulator 55 via the line 56 from the main line 42. Back pressure is supplied.

The reverse line 53 is connected to the auxiliary transmission 3
0 is led directly to the large first hydraulic chamber 34 ₁ of the pressure receiving area of the deceleration brake 34 in, thus, in the R range, the line pressure is introduced into the first hydraulic chamber 34 _1, the deceleration brake 34 is large fastening It will be concluded by force. In addition, a line 57 leading from the retreat line 53 to the second pressure increasing port 41b of the regulator valve 41 is provided.
Are branched to increase the adjustment value of the line pressure in the R range.

On the other hand, from the main line 42, the forward line 52 and the reverse line 53, the first, second, and third shift valves 61, 62, 6 for shifting in the main transmission 20 are provided.
3 and the fourth and fifth shift valves 64 and 65 for shifting in the subtransmission 30 are supplied with line pressure.

Each of the shift valves 61 to 65 has a control port 61 a to 65 a at one end, and a control source pressure line 66 led from the second reducing valve 45 is connected to a second transmission line for the main transmission. 1st to 3rd shift valve 61
The control source pressure line 67 led from the third reducing valve 46 is connected to each of the control ports 61a to 63a of the sub-transmission, and the fourth and fifth shift valves 64, 65 for the auxiliary transmission.
Are connected to the respective control ports 64a and 65a.

The control source pressure lines 66 and 67 are provided with first to fifth ON-OFF solenoid valves 71 to 75 corresponding to the first to fifth shift valves 61 to 65, respectively. These ON-OFF solenoid valves 71 to
Numeral 75 drains the inside of the control ports 61a to 65a of the shift valves 61 to 65 at the time of ON. Therefore, the spools of the shift valves 61 to 65 are provided with the corresponding ON-OFF solenoid valves 71 to 75.
Is on the left side of the drawing when is ON, and is on the right side when OFF.

The solenoid valves 71 to 71
75 ON / OFF combination, that is, each shift valve 61
According to the combination of the spool positions of ~ 65, the lines leading to the respective clutches and brakes from the main line 42, the forward line 52 or the reverse line 53 are selectively communicated. When the clutch and the brake are engaged, the first to fifth speeds and the reverse speed are obtained. In this case, the engagement pressure supplied to each clutch and brake is controlled to an appropriate value as follows.

That is, for the direct coupling clutch 24, coast brake 29, low reverse brake 26 and 3-4 brake 28 in the main transmission 20, a control valve 76 for reducing the line pressure to adjust it to a predetermined engagement pressure is provided. 77, 78, and 79, respectively, of which control valves 77, 7 for coast brake, low reverse brake, and 3-4 brake.
8, 79, the control ports 77a, 78a, 79
The control pressure adjusted by the first linear solenoid valve 80 is supplied to a through a line 81, and the engagement pressure is controlled in accordance with the control pressure.

The control pressure 76a of the direct-coupled clutch control valve 76 controls the engagement pressure supplied to the direct-coupled clutch 24 by a line 82 via a line 85 provided with a one-way orifice 83 and a third accumulator 84. The pressure is supplied as a control pressure, and the rise of the fastening pressure is controlled by the operation of the accumulator 84.

The first linear solenoid valve 8
0 is the line 4 from the first reducing valve 44
The control source pressure supplied via the controller 7 is adjusted in accordance with a control signal from a controller (see FIG. 4) to generate a control pressure corresponding to a shift speed and an operating state at that time. Further, the control valve 76 for the direct coupling clutch is used.
And the low reverse brake control valve 7
The ports 76b and 78b provided at one end of the pressure control line 8 are provided with the pressure regulating operation prohibiting lines 8 branched from the retreat line 53.
6 are connected, and in the R range, these ports 7
The line pressure is supplied to the control valves 7b and 78b, and the spool is fixed to the left position in the drawing.
6,782 pressure regulating operations are prevented. Further, when fastening pressure is supplied to the coast brake 29, the fastening pressure is supplied to a port 79b at one end of the 3-4 brake control valve 79 through a line 87, and the control valve 79 is controlled. The pressure operation is restricted.

The first linear solenoid valve 8
0 is applied to the control port 8 of the accumulator control valve 88 via line 81.
8a. The control valve 88 adjusts the line pressure supplied from the main line 42 via the line 89 in accordance with the control pressure from the first linear solenoid valve 80, and adjusts the line pressure for the third accumulator 84 and the fourth accumulator 90. , And this is applied by line 91 to both accumulators 8
4, 90 are supplied to the back pressure ports 84a, 90a.

On the other hand, for controlling the engagement pressure in the sub-transmission 30, the first direct coupling clutch 32 having a large pressure receiving area is used.
The hydraulic chamber 32 ₁ and the direct clutch control valve 101 to adjust the small second hydraulic chamber 32 ₂ engagement pressure supplied to the pressure receiving area, is supplied to a small second hydraulic chamber 34 _{and second} pressure receiving area of the deceleration brake 34 A deceleration brake control valve 102 for adjusting the engagement pressure and a second linear solenoid valve 103 are provided. The first hydraulic chamber 34 ₁ having a large pressure receiving area of the deceleration brake 34 is provided with:
As described above, the line pressure is directly supplied from the manual valve 43 via the retreat line 53 in the R range.

The second linear solenoid valve 103
The line pressure is supplied from the main line 42 as a control source pressure, and is adjusted according to a control signal from the controller, and then decelerated from the line 104 and the fifth shift valve 65 via the line 105 or the line 106. Control port 102 of brake control valve 102
a or the first hydraulic chamber 3 of the direct coupling clutch 32
2 ₁ communicates to adjust the oil pressure chamber 32 ₁ of the oil pressure. The control valve 102 for the deceleration brake is
When the control pressure generated by the second linear solenoid valve 103 as described above is supplied to the control port 102a, the main line 42 to the line 107, the fourth shift valve 64, the line 108, the fifth shift valve 65
And the line pressure supplied through the line 109 and adjusted according to the control pressure, the second supply to the hydraulic chamber 34 ₂ of the deceleration brake 34 which via a line 110.

On the other hand, the direct-coupled clutch control valve 101 is connected to the main line 42 through the line 107,
The line pressure is supplied through the shift valve 64 and the line 111, and after adjusting this, the one-way orifice 1
12, the line 113 and the fifth shift valve 65, so as to selectively supply the first hydraulic chamber 32 ₁ or the second hydraulic chamber 32 ₂ of the direct clutch 32 through the line 106 or line 114.

[0049] Then, the control port 101a of the lockup clutch control valve 101, fastening pressure itself supplied to the first hydraulic pressure chamber 32 ₁ or the second hydraulic chamber 32 ₂ of the direct clutch 32, the one-way orifice 115
And the line 11 provided with the fifth accumulator 116
And supplied as control pressure via 7
Therefore, the above-mentioned fastening pressure is changed to the fifth accumulator 116.
By the operation of, the apparatus rises through a certain shelf pressure state. The back pressure port 11 of the accumulator 116
A back pressure is supplied to 6a from the main line 42 via the line 118.

In the hydraulic circuit 40 having the above configuration, the first to fifth ON-OFF solenoid valves 71 to 7
The combination pattern of ON and OFF of No. 5 is as shown in Table 2, whereby the first to fifth forward speeds and the reverse speed can be obtained. Here, in Table 2, (1),
(2) shows the first speed and the second speed in the engine braking range.

[0051]

[Table 2] Next, the relationship between the combination of ON and OFF of each of the ON-OFF solenoid valves 71 to 75 and the shift speed will be specifically described according to Table 2.

First, in the first speed in which the engine brake is not operated, which is employed in the D range, etc., the first to third ON-OFF solenoid valves 71 to 73 are turned off on the main transmission 20 side.
In the N, OFF, and OFF states, the spools of the first to third shift valves 61 to 63 are located on the left, right, and right sides, respectively. In this state, the line 121 branched from the forward line 52 communicates with the line 122 via the first shift valve 61, and further the second shift valve 62
Communicates with the line 123 through the
Is shut off by the third shift valve 63. The other line 124 branched from the forward line 52 is shut off by the second shift valve 62, and the line 125 branched from the main line 42 is shut off by the first shift valve 61. Therefore, in this case, as described above, only the forward clutch 23 that is always engaged in the forward range is engaged, and a low speed stage in which the engine brake does not operate in the main transmission 20 is obtained.

In the auxiliary transmission 30, the fourth,
The fifth ON-OFF solenoid valves 74 and 75 are both O
In the FF state, the fourth and fifth shift valves 64, 6
5 is located on the right side, the main line 42 communicates with the line 108 via the line 107 and the fourth shift valve 64, and the control valve 10 for the deceleration brake via the fifth shift valve 65.
2, a line pressure is supplied to the control valve 102. At this time, the control pressure generated by the second linear solenoid valve 103 is supplied to the control port 102a of the deceleration brake control valve 102 via the line 104, the fifth shift valve 65, and the line 105, so that the line pressure is controlled. Is adjusted according to the control pressure, and after a predetermined fastening pressure,
The second hydraulic chamber 3 of the deceleration brake 34 via the line 110
4 ₂ is supplied to, deceleration brake 34 is engaged.

The direct coupling clutch 32 is connected to the first hydraulic chamber 3.
2 ₁ line 106, the fifth shift valve 65, line 1
13, communicates with the drain port of the fourth shift valve 64 via the direct clutch control valve 101 and line 111, and the second hydraulic chamber 32 _2, line 114
Is released by communicating with the drain port of the fifth shift valve 65 through the. As a result, the shift speed of the sub-transmission 30 becomes the low speed at which the engine brake operates, and the entire automatic transmission becomes the first speed at which the engine brake does not operate.

In the first speed in which the engine brake is used in the first range or the second range, the third solenoid valve 73 of the main transmission 20 is turned ON with respect to the first speed in which the engine brake is not operated, Along with this,
The spool of the third shift valve 63 is located on the left side. Therefore, in this case, the forward line 52 includes the branch line 121, the first shift valve 61, and the line 12
2. The line pressure is supplied to the control valve 78 through the second shift valve 62, the line 123, and the line 126 communicating with the low reverse brake control valve 78 via the third shift valve 63.

The line pressure supplied to the control valve 78 is applied to the first linear solenoid valve 80.
Is adjusted to a fastening pressure corresponding to the control pressure supplied to the control port 78a via the line 81 from the
27 is supplied to the low reverse brake 2 6 via.
As a result, in addition to the forward clutch 23, the low reverse brake 26 is engaged, and a low speed stage in which the engine brake operates in the main transmission 20 is obtained.
In the sub-transmission 30, the deceleration brake 34 is engaged as in the case of the first speed in which the engine brake is not operated, so that the first speed in which the engine brake is operated is obtained as the entire automatic transmission.

Next, in the 2nd speed of the engine brake non-operation adopted in the D range and the like, and in the 2nd speed of the engine brake operation adopted in the 1 range and the 2 range, etc. Engine braking 1
Only the shift speed of the subtransmission 30 changes with respect to the speed state.

That is, the fourth ON-
The OFF solenoid valve 74 is turned ON, and accordingly, the spool of the fourth shift valve 64 is located on the left side.
Accordingly, the line pressure supplied from the main line 42 to the fourth shift valve 64 via the line 107 is supplied from the fourth shift valve 64 to the direct-coupled clutch control valve 101 via the line 111, and After the rise is adjusted by the valve 101, the first hydraulic chamber 32 of the direct coupling clutch 32 is connected via the line 113, the fifth shift valve 65 and the line 106.
₁ will be supplied. Thereby, the auxiliary transmission 30
Becomes the high speed, and as a result, as a whole, the automatic transmission has the second speed in which the engine brake does not operate or the second speed in which the engine brake operates.

Further, at the third speed, the first to third ON-OFF solenoid valves 71 to 7
3 is OFF, ON, ON, and accordingly, the spools of the first to third shift valves 61 to 63 are shifted to the right, left,
It will be located on the left side. In this case, first, one branch line 121 from the forward line 52 communicates with the line 128 via the first shift valve 61, and further a line 129 which communicates with the coast brake control valve 77 via the third shift valve 63. Communicate with Accordingly, a line pressure is supplied to the control valve 77, and the pressure is adjusted to a predetermined fastening pressure in accordance with the control pressure supplied from the first linear solenoid valve 80 via the line 81, and then is adjusted via the line 130. The coast brake 29 is supplied to the coast brake 29.
Is concluded.

Further, the other branch line 124 from the forward line 52 communicates with the line 131 leading to the 3-4 brake control valve 79 via the second shift valve 62 to supply line pressure to the control valve 79. . A control pressure is supplied to the control valve 79 from the first linear solenoid valve 80 via a line 81, and an engagement pressure supplied to the coast brake 29 is supplied as a control pressure via a line 87. The engagement pressure adjusted according to these control pressures is supplied to the 3-4 brake 28 via the line 132.

As a result, in the main transmission 20, the 3-4 brake 28 is engaged in addition to the forward clutch 23,
In addition, by engaging the coast brake 29, a middle gear in which the engine brake operates is obtained.

On the other hand, in the auxiliary transmission 30, both the fourth and fifth ON-OFF solenoid valves 74 and 75 are turned off.
In the state of F, the shift speed is set to the low speed at which the engine brake operates as in the case of the first speed described above. Therefore, as a whole, the automatic transmission has a predetermined speed reduction ratio and can obtain the third speed at which the engine brake operates.

In the fourth speed, the fourth and fifth ON-OFF solenoid valves 74 and 75 of the auxiliary transmission 30 are turned ON from the state of the third speed, and the fourth and fifth shift valves 64 and 65 are turned on. The spool is located on the left side, so that the line pressure is first controlled from the main line 42 through the line 107, the fourth shift valve 64, and the line 111 as in the case of the second speed. And the control valve 1
The rise is adjusted at 01, and the specified fastening pressure is reached.
From the line 113 and the fifth shift valve 65, this time via the line 114, the second hydraulic chamber 32 of the direct-coupled clutch 32
₂ will be supplied. As a result, the direct coupling clutch 3
2 is engaged, and the speed stage of the subtransmission 30 becomes the high speed stage.
Since the main transmission 20 is set to the middle speed as in the case of the third speed, the speed of the entire automatic transmission is the fourth speed.

Further, at the fifth speed, the first to third ON-OFF solenoid valves 71 to
73 turns OFF, ON, and OFF, and the spools of the first to third shift valves 61 to 63 are located on the right, left, and right sides. Therefore, the line 125 branched from the main line 42 is connected to the line 13 via the first shift valve 61.
3, and further communicates with a line 134 that communicates with the direct-coupled clutch control valve 76 via the third shift valve 63, so that line pressure is supplied to the control valve 76. And
The engagement pressure adjusted by the control valve 76 is supplied to the direct coupling clutch 24 via the line 82, and the clutch 24 is engaged. Thereby, the main transmission 20
In, the forward clutch 23 and the direct coupling clutch 24 are engaged, and the shift speed is set to the high speed. When the direct coupling clutch 24 is engaged, the engagement pressure is supplied through a constant shelf pressure state by the action of the third accumulator 84.

On the other hand, the auxiliary transmission 30 is provided with the fourth and fifth ON-OFF solenoid valves 7 as in the case of the fourth speed.
Both the gears 4 and 75 are in the ON state, and the shift speed is set to the high speed stage. As a result, the automatic transmission as a whole can obtain the fifth speed.

Further, at the reverse speed when the manual valve 43 is operated to the R range, the reverse line 53 is communicated with the main line 42 via the manual valve 43, and the first to third ON-OFF solenoid valves are connected. 71 to 73 are OFF, OFF, and OFF, and the spools of the first to third shift valves 61 to 63 are all located on the right side.

For this reason, first, the line 125 branched from the main line 42 is, as in the case of the fifth speed described above,
A line 134 communicates with the line 133 via the first shift valve 61, and further communicates with the direct-coupled clutch control valve 76 via the third shift valve 63.
Therefore, the line pressure is supplied to the control valve 76. In this case, the line pressure is supplied to the port 76b at one end of the control valve 76 from the retreat line 53 via the line 86, and the spool of the control valve 76 is fixed to the left side in the drawing. The line pressure supplied from the line 134 is supplied to the direct coupling clutch 24 via the line 82 without being reduced in pressure, and the direct coupling clutch 24 is engaged with a high engagement pressure.

The retreat line 53 has an orifice 135 having a different throttle amount in the supply and discharge directions of the hydraulic oil.
The low reverse brake control valve 78 is communicated via the line 136, the third shift valve 63, and the above-mentioned line 126, and the control valve 78 is operated in the same manner as in the case of the first speed of the engine brake operation.
Supply line pressure to In this case, the port 78b at one end of the control valve 78 is connected to the retreat line 53.
When the line pressure is introduced by the line 86 branched from the control valve 78, the spool of the control valve 78 is fixed to the left side in the drawing. Therefore, the line 12
6 is supplied to the low reverse brake 26 without being adjusted by the control valve 78, and the line pressure supplied by the low reverse brake 2
6 is fastened with a high fastening pressure.

As a result, in the main transmission 20, the direct coupling clutch 24 and the low reverse brake 26 are engaged, and the reverse gear is obtained. Then, in the sub-transmission 30, the fourth and fifth ON-OFF solenoid valves 74, 7
5 are both OFF and the speed is set to the low speed at which the engine brake operates, and a reverse speed with a large reduction ratio can be obtained.

When the engagement pressure is supplied to the low reverse brake 26, the operating oil is introduced into the fourth accumulator 90 from the line 136 via the line 137, so that the engagement pressure is reduced to a predetermined value. It will gradually rise after the shelf pressure state.

In addition to the above configuration, the hydraulic circuit 40 includes a lock-up clutch 1 in the torque converter 10.
, A lock-up control valve 143, an ON-OFF solenoid valve 144 for lock-up control, and a duty solenoid valve 145.
The engagement and release control of the lock-up clutch 17 and the slip control for slipping the clutch 17 are performed.

The hydraulic circuit 40 includes a duty solenoid valve 49 for adjusting line pressure, and first to fifth ON-OFF solenoid valves 71 to 7 for shifting.
5. First and second linear solenoid valves 80 and 103 for adjusting the fastening pressure, ON-OFF solenoid valve 144 for lock-up control, and duty solenoid valve 1
The unit 45 is controlled by a control signal from the controller 160 as shown in FIG. The controller 160 receives a signal from a sensor 161 for detecting the vehicle speed, a signal from a sensor 162 for detecting the throttle opening of the engine, and a sensor 163 for detecting a shift position (range) selected by the driver. And the like, and the solenoid valves are controlled in accordance with the operating state indicated by these signals and the driver's request.

The controller 160 includes a first rotation sensor 1 for detecting the number of rotations on the input side of the main transmission 20.
64, a second rotation sensor 165 for detecting the rotation speed on the output side of the main transmission 20 (the input side of the subtransmission 30), and a third rotation sensor 1 for detecting the rotation speed on the output side of the subtransmission 30
66 are connected. And the controller 16
0 indicates that these sensors 164 to 166 are to be described later.
The gear ratios of the main transmission 20 and the auxiliary transmission 30 are calculated based on the signals from the control unit 30 and the supply / discharge control of the engagement pressure is performed according to the calculated value.

The automatic transmission according to the present embodiment has the above-described configuration. As is apparent from Table 1 above, the automatic transmission changes from the third speed state to the second speed and from the second speed state to the third speed. During the shift, the gear ratio change of the gear ratio of the main transmission 20 and the auxiliary transmission 30 are simultaneously performed in the reverse direction, and the coast brake for engine braking is performed during the former 3-2 shift. 29 is released from the fastening state.

In this embodiment, the above 3-2
The shift is executed as follows in accordance with the flowchart shown in FIG.

That is, after reading various signals in step S1, the controller 160 reads out various signals in step S2.
It is determined whether the value of the second shift flag F _3-2 is 1 or not. Here, the 3-2 shift flag _F3-2 is cleared to 0 in the initial state and is set to 1 when the 3-2 shift command is issued.

Here, assuming that the 3-2 shift flag F3-2 is not set to 1, the controller 160
Determines whether 3-2 shift command proceeds to step S2 or lath step S4 is outputted. And 3-2
When the shift command is output, the process proceeds to step S5 to set 1 to the 3-2 shift flag F3-2, and then proceeds to step S6 to execute a predetermined 3-2 shift control and to execute step S7. It is determined whether or not the 3-2 shift has been completed, and if it is determined that the 3-2 shift has been completed, the 3-2 shift flag F3-2 is cleared to 0 in step S8, and the control ends.

Here, the outline of the 3-2 shift control will be described. The controller 160 compares the actual throttle opening and the vehicle speed with a shift map in which the throttle opening and the vehicle speed are set as parameters in advance. When these values cross the 3-2 downshift line constituting the shift map, a 3-2 shift command is output. And
When the rate of change of the throttle opening is greater than a predetermined lower limit, predetermined torque demand control is executed.

That is, the controller 160 releases the engagement pressure of the coast brake 29 of the main transmission 20 and reduces the engagement pressure of the 3-4 brake 28 to a predetermined value, for example, at the time of gentle acceleration with a small change rate of the throttle opening. After the shelf pressure state, the main transmission 2
The shift stage of 0 is downshifted from the middle speed stage to the low speed stage.

Then, the deceleration brake 34 of the auxiliary transmission 30
In this case, the speed of the auxiliary transmission 30 is shifted up from the low speed to the high speed by releasing the engagement pressure of the main transmission 20 and supplying the engagement pressure to the direct coupling clutch 32. In response to the increase in the ratio,
The engagement operation of the direct coupling clutch 32 in the auxiliary transmission 30 is controlled by the second linear solenoid valve 103 so that the gear ratio of the direct transmission clutch 32 decreases.

That is, the controller 160 includes first and second transmissions, which are respectively disposed on the input side and the output side of the main transmission 20.
The gear ratio of the main transmission 20 is calculated based on the signals from the second rotation sensors 164 and 165, and the gear ratio of the subtransmission 30 is reduced at each time point so that the gear ratio of the auxiliary transmission 30 decreases in accordance with the increase of the gear ratio. The target gear ratio of the subtransmission 30 is set. Then, the target gear ratio and the input side and the output side of the auxiliary transmission 30 are respectively set. The second linear solenoid valve is compared with the actual gear ratio at each time point calculated based on the signals from the second and third rotation sensors 165 and 166 arranged so as to eliminate the deviation. The engagement operation of the direct connection clutch 103 by the feedback control 103 is feedback-controlled.

While the shifting operation from the third speed to the second speed is in progress, the gear is returned to the original third speed.
When the shift command is output, the controller 160 executes the following control.

Returning to the flowchart of FIG. 5, when the controller 160 determines in step S3 that the 2-3 shift command has been issued, the controller 160 starts a backup timer set to a predetermined time in steps S9 to S11 and sets a coast time. While the brake 29 is held in the released state, other frictional elements, specifically, the main transmission 20
-4 The brake 28, the direct coupling clutch 32 of the auxiliary transmission 30, and the deceleration brake 34 are returned to the third speed state in the engaged state.

Then, in steps S12 and S13, it is determined whether the backup timer has expired and the sub-transmission 30
The end of the switching operation is determined, and when the backup timer has expired or the switching operation of the auxiliary transmission 30 has been completed, the routine proceeds to step S14, where the engagement operation of the coast brake 29 is started, and -2
The gear shift flag _F3-2 is cleared to zero.

Note that the end of the switching operation of the auxiliary transmission 30 is determined based on, for example, signals from the second and third rotation sensors 165 and 166.

According to this embodiment, the following operation can be obtained.

That is, as shown in FIG. 6, the 3-2 shift control is started based on the 3-2 command. When the 3-2 shift control is a downshift command accompanying a decrease in engine load, In the main transmission 20, the engagement pressure of the coast brake 29 is exhausted, and the engagement pressure of the 3-4 brake 28 is exhausted via a predetermined shelf pressure state. Be started. In the sub-transmission 30, the engagement pressure of the deceleration brake 34 is exhausted. When the gear ratio of the main transmission 20 starts to change, the engagement pressure is supplied to the direct coupling clutch 32, and
The engagement force of the direct coupling clutch 32 is feedback-controlled so that the gear ratio of the subtransmission 30 increases in response to the decrease in the gear ratio of the main transmission 20.

If it is assumed that the accelerator pedal is released during the feedback control and a 2-3 shift command for returning to the original third speed is generated, the main transmission 20 uses the 3-4 brake 28 during the releasing operation. The engagement pressure is increased, and the shift speed is returned to the middle speed. On the other hand, in the auxiliary transmission 30, the feedback control of the engagement pressure of the direct coupling clutch 32 is stopped to release the pressure, and the engagement pressure is supplied to the released deceleration brake 34 to return the gear stage to the high gear stage. . At this time, since the coast brake 29 is held in the released state, the vehicle is transiently idle and the shock due to the shifting operation is greatly reduced.

Then, for example, when the switching operation to the low speed stage in the auxiliary transmission 30 is completed, the coast brake 2
9, the supply of the fastening pressure to the brake 29 starts.
Is in an emblem state.

[0090]

As described above, according to the present invention, the main transmission and the auxiliary transmission having the transmission mechanisms that operate independently of each other are provided, and the friction element for engine braking is engaged at a predetermined gear. Automatic transmission in which the main transmission and the auxiliary transmission simultaneously perform a shift operation during a shift in which the predetermined shift speed and another shift speed at which the engine brake friction element is released are switched. In the above, at the time of shifting from a predetermined gear at which the friction element for engine braking is engaged to another gear at which the friction element is released, the engine is returned to the original predetermined gear due to a decrease in engine load during the gear shifting. When such a shift request occurs,
Since the engaged state of the other friction elements of the main transmission and the auxiliary transmission is returned to the state of the predetermined shift speed while the released state of the friction element for engine brake is maintained, a large shock occurs. This prevents the gear shifting operation from being performed well.

[0091]

Further, after the releasing operation of the friction element for engine braking and the shifting operation of the main and auxiliary transmissions are started,
When a shift request is issued to return the gear to the original gear at which the friction element for engine braking is engaged due to a decrease in engine load, another friction is generated in a state where the release state of the friction element for engine brake is maintained. Since the fastening state of the elements is returned to the original state, the control is not complicated, and the shock is greatly reduced.

[Brief description of the drawings]

FIG. 1 is a skeleton diagram of an automatic transmission according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a structure of a sub-transmission in the automatic transmission.

FIG. 3 is a circuit diagram showing a hydraulic circuit of the automatic transmission.

FIG. 4 is a control system diagram for each solenoid valve in the hydraulic circuit of FIG. 3;

FIG. 5 is a flowchart illustrating 3-2 shift control in the present embodiment.

FIG. 6 is a time chart illustrating the operation of the present embodiment.

[Explanation of symbols]

 Reference Signs List 20 main transmission 21 front planetary gear mechanism 22 rear planetary gear mechanism 28 3-4 brake 29 coast brake 30 auxiliary transmission 31 planetary gear mechanism 32 direct coupling clutch 34 deceleration brake 160 controller 164 first rotation sensor 165 second rotation sensor 166 3 rotation sensor

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tatsutoshi Mizobe 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Mazda Co., Ltd. (56) References JP-A-61-252948 (JP, A) 1-199037 (JP, A) JP-A-64-15560 (JP, A) JP-A-61-241558 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F16H 59/00 -61/12 F16H 61/16-61/24 F16H 63/40-63/48

Claims (2)

(57) [Claims] 1. A main transmission and a sub transmission having a transmission mechanism that operates independently of each other .
The main shift is performed during a shift in which the selected engine brake friction element is configured to be engaged at a predetermined speed, and the predetermined speed and another speed at which the engine brake friction element is released are switched. In an automatic transmission in which the shifting operation is performed simultaneously between the transmission and the sub-transmission,
Provided with a determining means for determining completion of the switching operation, when downshift to other gear position the predetermined shift stage friction element for the engine brake is released, the frictional element for the d <br/> down Jin brake When the shift request for returning the shift speed to the predetermined shift speed is generated due to a decrease in the engine load after the release operation of the main transmission and the shift operation of the subtransmission are started, the friction element for engine brake main transmission and the sub after the engagement state of the other frictional elements of the transmission was restored to the state of the predetermined speed change stage, the determining means determine the end of the switching operation of the auxiliary transmission in a state of holding the released state
A control device for an automatic transmission, further comprising control means for starting a fastening operation of the friction element for engine braking when the setting is made. 2. The control device according to claim 1, wherein the determining unit is configured to determine an input-side rotational speed of the auxiliary transmission.
And a rotation sensor on the output side of the auxiliary transmission.
Judgment based on the signal from the detected rotation sensor
The control device for an automatic transmission according to claim 1, wherein: