JPH05332434A - Control device for automatic transmission - Google Patents

Abstract

PURPOSE:To reduce the shock due to the speed change operation, and perform the speed change operation smoothly at the time of speed change for required reset by resetting the connected condition of each friction element of both a main and an auxiliary transmission to the predetermined speed step under the condition that the released condition of a friction element for an engine brake is maintained. CONSTITUTION:An automatic transmission 1 consists of a torque converter 10, a main transmission 20 arranged on the same axis as the torque converter 10, and an auxiliary transmission 30 arranged in parallel with these axes. In this case, at the time of speed change for the required reset, the connecting pressure of a 3-4 brake of the main transmission 20 is raised, and on the other hand, the connecting pressure of a direct connecting clutch 32 of the auxiliary transmission 30 is discharged, and the connecting pressure is supplied to a speed reduction brake under the released condition to reset the speed step to a high speed step. A coast brake 29 of the main transmission 20 is maintained under the released condition. A vehicle is thereby under the transient idle travelling condition to reduce the shock due to the speed change operation. Thereafter, the coast brake 29 is connected to provide the engine brake condition.

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 adapted to engage a friction element for engine braking 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 a power transmission path of the speed change mechanism is switched by selectively engaging a plurality of friction elements so as to automatically shift to a shift speed most suitable for an operating condition. 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, 3rd or 4th speed) used during high-speed traveling. There are some that are made to conclude.

On the other hand, in recent years, in this type of automatic transmission, the number of shift stages has been increased in order to improve fuel efficiency and output performance. For example, Japanese Patent Laid-Open No. 61-9974.
No. 5 discloses a multi-stage system in which a main transmission and an auxiliary transmission having transmission mechanisms that operate independently of each other are connected in series, and the output of one transmission is further shifted by the other transmission. A configuration adapted to perform gear shifting is shown.

[0004]

In an automatic transmission of this type, for example, a preset shift pattern is compared with an actual operating state indicated by vehicle speed, throttle opening, etc., and the operating state is A shift control for downshifting or upshifting a shift stage is performed based on a shift command output when a shift line forming a shift pattern is exceeded. For example, a shift operation based on a downshift shift command. If the accelerator pedal is returned before the completion of the above, an upshift shift command for returning the shift stage to the original shift stage may be output as the engine load decreases.

In such a case, when the upshift gearshift for returning to the original gear stage is performed after the gearshift operation based on the preceding downshift gearshift command is completed,
Even if the accelerator pedal is not depressed, the gear position is temporarily downshifted, which makes the driver feel uncomfortable.

In order to solve such a problem, it is conceivable to carry out the shift control for returning the shift stage to the original shift stage when the shift command for returning to the original shift stage is output.
An automatic shift configured so that the main transmission and the sub-transmission simultaneously perform a shift operation at the time of 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 a machine, a large shift shock occurs due to the shock resulting from the return of the friction element for engine braking to the engaged state and the shock resulting from the return of the engaged state of other friction elements to the original gear stage state. May occur.

In particular, when the gear stage to which the friction element for engine braking is engaged and the other gear stage to which the friction element is released are switched, the change of the gear ratio between the main transmission and the sub transmission is reversed. In an automatic transmission that is configured to simultaneously perform a gear shifting operation in one direction, a predetermined value on the auxiliary transmission side is set so that the gear ratio of the auxiliary transmission changes in the opposite direction in response to the change of the gear ratio of the main transmission. If feedback control of the engaging force of the friction element is performed, if the shift request for returning to the original gear stage occurs due to the reduction of the engine load during the shift, the main shift is performed by engaging the friction element for engine braking. There is a possibility that the gear ratio of the machine may change abnormally, the gear change control may be significantly complicated, and the gear change shock may increase.

According to the present invention, the main transmission and the sub-transmission are simultaneously operated at the time of gear shifting in which a predetermined gear stage to which a friction element for engine braking is engaged and another gear stage to which the friction element is released are switched. In an automatic transmission in which a gear shift operation is performed, the above-mentioned problem is dealt with when a shift request for returning to the above-mentioned predetermined shift stage occurs due to a reduction in engine load during a shift. The purpose is to return to the stage.

[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 the first invention) is a main transmission having a transmission mechanism that operates independently of each other. An auxiliary transmission is provided, the friction element for engine braking is configured to be engaged at a predetermined speed, and the predetermined speed is switched to another speed where the friction element for engine braking is released. In an automatic transmission in which the main transmission and the sub-transmission simultaneously perform a gear shift operation during a gear shift, the engine brake friction is changed during the gear shift from the predetermined gear to another gear where the engine brake friction element is released. After a release operation of the elements and a shift operation of the main transmission and the auxiliary transmission are started, when a shift request for returning the shift stage to the predetermined shift stage is generated due to a reduction in engine load, Note: While the released state of the friction element for engine braking is maintained, the engagement state of the other friction elements of the main transmission and the auxiliary transmission is returned to the state of the above-mentioned predetermined shift stage, and then the engagement of the friction element for engine braking is performed. It is characterized in that a control means for starting the operation is provided.

The invention of claim 2 of the present application (hereinafter referred to as the second
According to another aspect of the invention, there is provided a control device for an automatic transmission, which includes a main transmission and a sub-transmission, each of which has a transmission mechanism that operates independently of each other. In addition, the gear ratio changes between the main transmission and the auxiliary transmission at the time of a gear shift in which the predetermined gear and the other gear that releases the friction element for engine braking are switched, and the gear shift operation in the opposite direction is performed. In an automatic transmission that is performed at the same time, feedback control of the fastening force of a predetermined friction element on the auxiliary transmission side is performed so that the gear ratio of the auxiliary transmission changes in the opposite direction in response to the change of the gear ratio of the main transmission. And a feedback means for controlling the engine brake friction element during the shift from the predetermined shift stage to another shift stage where the engine brake friction element is released. When a shift request for returning the shift stage to the predetermined shift stage is generated due to a decrease in the engine load after the start of the speed change operation of the speed machine, the main shift is performed while maintaining the released state of the friction element for engine brake. A control means is provided for returning the engagement state of the other friction element of the engine and the auxiliary transmission to the state of the above-mentioned predetermined shift stage, and thereafter starting the engagement operation of the friction element for engine braking.

[0011]

According to the present invention having the above construction, the following operation can be obtained.

That is, according to the first aspect of the present invention, the engine load is reduced during a shift at the time of a shift in which the predetermined shift stage in which the engine braking friction element is engaged is switched to another shift stage in which the friction element is released. If a shift request is made to return to the original predetermined shift speed due to, the engagement state of the other friction elements of the main transmission and the auxiliary transmission is maintained while the released state of the engine braking friction element is maintained. Since the state of the predetermined gear is restored, the occurrence of a large shock is prevented and the gear shifting operation is favorably performed.

In particular, according to the second aspect of the invention, the main transmission and the sub-transmission are operated at the time of a shift in which the predetermined speed stage to which the engine braking friction element is engaged and the other speed stage to which the friction element is released are switched. In an automatic transmission in which a gear ratio change and a gear shift operation in the opposite direction are simultaneously performed, the gear shift operation of the sub-transmission proceeds while appropriately responding to the gear shift operation of the main transmission during the gear shift. Therefore, the shift shock is effectively reduced.

Moreover, 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 for returning the shift stage to the original shift stage in which the engine brake friction element is fastened is generated due to the reduction of the engine load, the other released state of the engine brake friction element is maintained. Since the fastening state of the friction element is restored to the original state, complication of control is avoided and shock is greatly reduced.

[0015]

EXAMPLES Examples of the present invention will be described below.

As shown in FIG. 1, an automatic transmission 1 according to this embodiment has 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 arranged to face the pump 12 and driven by hydraulic oil by the pump 12, and a turbine 13 arranged between the pump 12 and the turbine 13 and supported by a transmission case 3 via a one-way clutch 14. Stator 1
5, a converter output shaft 16 connected to the turbine 13, and a lockup 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
An oil pump 4 driven by the engine output shaft 2 via the torque converter 10 is arranged between the oil pump 4 and the engine 0.

The main transmission 20 has 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 counter 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 the sun gear 2 of the rear planetary gear mechanism 22 via the direct coupling clutch 24.
The sun gear 21a of the front planetary gear mechanism 21 and the ring gear 22b of the rear planetary gear mechanism 22 are coupled to each other.

Further, a first one-way clutch 25 and a low reverse brake 26 are arranged in parallel between the ring gear 21b of the front planetary gear mechanism 21 and the transmission case 3, and the rear planetary gear mechanism 22 is provided. 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 them. Then, the pinion carriers 21c, 22c of the front planetary gear mechanism 21 and the rear planetary gear mechanism 22 are coupled, and these are connected to the main transmission 2
An intermediate gear 5 that transmits power from 0 to the auxiliary transmission 30 is connected.

With such a 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 high 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 which is always meshed with the intermediate gear 5 in the main transmission 20 is connected to the ring gear 31a of the planetary gear mechanism 31. And the ring gear 31
A direct coupling clutch 32 is arranged between a and the sun gear 31b, and a third one-way clutch 33 and a reduction brake 34 are arranged in parallel between the sun gear 31b and the transmission case 3. Then, the planetary gear mechanism 31
The output gear 7 is connected to the pinion carrier 31c of the left and right drive wheels (not shown) from the gear 7 through a differential device.
Power is transmitted to.

The sub-transmission 30 can shift the power input from the main transmission 20 via the intermediate gears 5 and 6 to two forward gears, a low-speed gear and a high-speed gear, and output it to the output gear 7. It is like this.

That is, when the direct coupling clutch 32 is released, the sun gear 31 of the planetary gear mechanism 31 is driven by the third one-way clutch 33 or the reduction brake 34.
By fixing b, the power from the intermediate gear 6 input to the ring gear 31a of the planetary gear mechanism 31 is decelerated 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 will operate.

Further, the direct coupling clutch 32 is engaged,
If 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, whereby 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 (direct connection stage) can be obtained.

In this way, the main transmission 20 can obtain three forward gears and one reverse gear, and the auxiliary transmission 3
By setting 0, two high and low shift speeds can be obtained with respect to the output of the main transmission 20, so that the automatic transmission as a whole can obtain 6 shift speeds for forward travel and main shifts for reverse travel. The reverse gear as a whole is obtained by combining the reverse gear of the machine 20 and the low gear of the auxiliary transmission 30 to which the deceleration brake 34 is engaged. And in this example,
As the forward shift speed, a predetermined five speeds among the above six speeds are adopted.

Here, the operating states of the clutches and brakes at the respective shift speeds of the forward 5 speeds and the reverse 1 speed are summarized in Table 1. In addition, in Table 1, (◯) indicates that the engagement is performed only in the range for engine braking.

[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 double structure piston as shown in FIG. 2 is adopted.

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

Then, the first hydraulic chamber 32 _{1 at} the back of the first piston 32e into which the fastening pressure is introduced by the oil passage 36 and the second hydraulic pressure at the back of the second piston 32f in which the fastening pressure is introduced through the oil passage 37. Chamber 32 ₂ is provided, and when the same fastening pressure is introduced into these hydraulic chambers 32 ₁ and 32 ₂ , the first
When introduced into the hydraulic chamber 32 ₁ , a larger fastening force can be obtained than when introduced into the second hydraulic chamber 32 ₂ .

In the deceleration brake 34, a plurality of friction plates 34a and 34b on the driving side and the driving side are alternately arranged between the drum member 32b of the direct coupling clutch 32 and the transmission case 3, and a return spring is provided. A piston 34d that fastens these friction plates 34a and 34b against 34c is provided, and at the back of the piston 34d, there is a first hydraulic chamber 34 ₁ on the inner peripheral side having a large pressure receiving area and an outer peripheral side having a small pressure receiving area. The second hydraulic chamber 34 ₂ is concentrically provided. When the same fastening pressure is introduced into these hydraulic chambers 34 ₁ and 34 ₂ , the case where the fastening pressure is introduced into the first hydraulic chamber 34 ₁ is introduced into the second hydraulic chamber 34 ₂ . In this case, a larger fastening force can be obtained.

Next, a hydraulic circuit for forming a shift stage according to the operating condition or the driver's request by selectively engaging each clutch and brake according to Table 1 will be described.

As shown in FIG. 3, in the hydraulic circuit 40, first, a regulator valve 4 for adjusting the pressure of the hydraulic oil discharged from the oil pump 4 to a predetermined line pressure.
1, a line pressure adjusted by the regulator valve 41 is operated by a main line 42 by a driver, and a first to third reducing valves for generating various control source pressures. 44,
45, 46 and so on.

These reducing valves 44 to 46
Of these, 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. Then, the control pressure adjusted by the duty solenoid valve 49 is supplied to the control port 48a of the modulator valve 48, and the duty solenoid valve 4
A modulator pressure is generated from the control source pressure according to a duty ratio of 9 (ratio of ON time in one ON / OFF cycle), and this modulator pressure is also applied to a first pressure increase of the regulator valve 41 via a line 50. Port 4
1a, whereby the line pressure is increased according to the duty ratio. In this case, the duty ratio is set according to, for example, the throttle opening degree of the engine, so that the line pressure is adjusted to a value according to the throttle opening degree. The line 50 supplied to the first pressure increasing port 41 a of the first pressure increasing port 41 has a first accumulator 51 for suppressing the pulsation of hydraulic pressure caused by the periodic ON / OFF operation of the duty solenoid valve 49.
Is installed.

The manual valve 43 has D,
3, 2, 1 forward range, R (reverse) range, N
It is possible to set a (neutral) range and a P (parking) range. In the forward range, the main line 42 is connected to the forward line 52, and in the R range, it is connected to the backward line 53.

The advancing line 52 is guided to the advancing clutch 23 through the orifice 54 whose throttle amount is different between when the hydraulic oil is supplied and when the hydraulic oil is discharged.
In each of the forward ranges of 3, 2, and 1, the forward clutch 23 is always engaged. In this case, the forward line 52 is provided with a second accumulator 55 for reducing a shock when supplying the fastening pressure to the forward clutch 23, and the accumulator 55 is connected to the accumulator 55 from the main line 42 through the line 56. Back pressure is supplied.

The reverse line 53 is used for the auxiliary transmission 3
At 0, the deceleration brake 34 is directly guided to the first hydraulic chamber 34 ₁ having a large pressure receiving area. Therefore, in the R range, the deceleration brake 34 has a large engagement due to the line pressure introduced into the first hydraulic chamber 34 _1. It will be concluded by force. In addition, a line 57 leading from the backward line 53 to the second pressure increasing port 41b of the regulator valve 41.
Is branched and the adjustment value of the line pressure is increased 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 line pressures are supplied to the fourth and fifth shift valves 64 and 65 for shifting in the auxiliary transmission 30.

Each of the shift valves 61 to 65 is provided with control ports 61a to 65a at one end, and the control source pressure line 66 led from the second reducing valve 45 is the first for the main transmission. 1st-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 first to sixth control ports 63a to 63a, and the fourth and fifth shift valves 64 and 65 for the auxiliary transmission.
Of the control ports 64a and 65a.

On the control source pressure lines 66 and 67, first to fifth ON-OFF solenoid valves 71 to 75 are installed in correspondence with the first to fifth shift valves 61 to 65. These ON-OFF solenoid valves 71 to
When the valve 75 is turned on, the control valves 61a to 65a of the shift valves 61 to 65 are drained. Therefore, the spools of the shift valves 61 to 65 have corresponding ON-OFF solenoid valves 71 to 75.
When is ON, it is located on the left side in the drawing, and when it is OFF, it is located on the right side.

And, these solenoid valves 71 to
ON / OFF combination of 75, that is, each shift valve 61
Lines leading to the respective clutches and brakes are selectively communicated from the main line 42, the forward line 52 or the reverse line 53 depending on the combination of the spool positions of ~ 65, and thereby each line according to the point shown in Table 1 above. The clutch and brake are engaged, and the first to fifth speeds and the reverse speed are obtained. In that 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, the coast brake 29, the low reverse brake 26 and the 3-4 brake 28 in the main transmission 20, the control valve 76 for reducing the line pressure to adjust it to a predetermined engagement pressure. 77, 78, 79, of which control valves 77, 7 for coast brake, low reverse brake, and 3-4 brake are provided.
For 8, 79, control ports 77a, 78a, 79
The control pressure adjusted by the first linear solenoid valve 80 is supplied to a via a line 81, and the fastening pressure is controlled in accordance with the control pressure.

Further, in the control port 76a of the direct coupling clutch control valve 76, the fastening pressure itself supplied to the direct coupling clutch 24 by the line 82 is passed through the line 85 provided with the one-way orifice 83 and the third accumulator 84. It 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 described above
0 indicates the line 4 from the first reducing valve 44.
The control source pressure supplied via 7 is adjusted according to the control signal from the controller (see FIG. 4), and the control pressure according to the gear stage and the operating state at that time is generated. Further, the control valve 76 for the direct coupling clutch
And the above-mentioned low reverse brake control valve 7
The ports 76b and 78b provided at one end of the line 8 are provided with a pressure regulating operation inhibiting line 8 branched from the retreat line 53.
6 are each connected, and in the R range, these ports 7
A line pressure is supplied to 6b and 78b, and the spool is fixed to the left position in the drawing, whereby the control valve 7 for the direct coupling clutch and the low reverse brake 7
The pressure adjusting operation of 6,78 is blocked. Further, when the fastening pressure is supplied to the coast brake 29, the fastening pressure is supplied to the port 79b at one end of the 3-4 brake control valve 79 via the line 87 to adjust the control valve 79. The pressure action is restricted.

Also, the first linear solenoid valve 8
The control pressure generated by 0 is supplied to the control port 8 of the accumulator control valve 88 via the line 81.
8a is also supplied. The control valve 88 adjusts the line pressure supplied from the main line 42 through the line 89 according to the control pressure from the first linear solenoid valve 80, and is used for the third accumulator 84 and the fourth accumulator 90. Back pressure of the two accumulators 8 via line 91
4, 90 back pressure ports 84a, 90a are supplied.

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

The second linear solenoid valve 103
Is supplied from the main line 42 as a control source pressure, which 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 the brake control valve 102
a, or the first hydraulic chamber 3 of the direct coupling clutch 32.
The hydraulic pressure of the hydraulic chamber 32 ₁ is adjusted by communicating with 2 ₁ . The deceleration brake control valve 102 is
While the control pressure generated by the second linear solenoid valve 103 as described above is being supplied to the control port 102a, the main line 42 to the line 107, the fourth shift valve 64, the line 108, and the fifth shift valve 65.
Also, the line pressure supplied via the line 109 is adjusted according to the control pressure, and this is supplied to the second hydraulic chamber 34 ₂ of the deceleration brake 34 via the line 110.

On the other hand, for the direct coupling clutch control valve 101, the main line 42 to the line 107, the fourth line
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 are selectively supplied to the first hydraulic chamber 32 ₁ or the second hydraulic chamber 32 ₂ of the direct coupling clutch 32 via the line 106 or the line 114.

At the control port 101a of the direct coupling clutch control valve 101, the fastening pressure itself supplied to the first hydraulic chamber 32 ₁ or the second hydraulic chamber 32 ₂ of the direct coupling clutch 32 is the one-way orifice 115.
And the line 11 provided with the fifth accumulator 116
It is supplied as a control pressure via 7.
Therefore, the fastening pressure is the fifth accumulator 116.
By the operation of, it will rise after a certain shelf pressure state. The back pressure port 11 of this accumulator 116
Back pressure is supplied to 6a from the main line 42 through a line 118.

In the hydraulic circuit 40 having the above structure, the first to fifth ON-OFF solenoid valves 71 to 7 are provided.
The combination pattern of ON and OFF of No. 5 is as shown in Table 2, and thereby the forward 1-5th speed 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, referring to Table 2, the relationship between the ON / OFF combinations of the ON-OFF solenoid valves 71 to 75 and the shift speed will be specifically described.

First, in the first speed in which the engine brake employed in the D range or the like does not operate, the first to third ON-OFF solenoid valves 71 to 73 on the main transmission 20 side are turned off.
In the N, OFF, and OFF states, the spools of the first to third shift valves 61 to 63 are located on the left side, the right side, and the right side, 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.
Through the line 123.
Is shut off by the third shift valve 63. Similarly, the other line 124 branched from the forward line 52 is blocked by the second shift valve 62, and the line 125 branched from the main line 42 is blocked by the first shift valve 61. Therefore, in this case, as described above, only the forward clutch 23, which is always engaged in the forward range, is engaged, and the low speed stage in which the engine brake does not operate in the main transmission 20 is obtained.

In the sub transmission 30, the fourth,
5th ON-OFF solenoid valves 74 and 75 are both O
In the FF state, the fourth and fifth shift valves 64, 6
Since the spools of No. 5 are both 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 further the deceleration brake control valve 10 via the fifth shift valve 65.
The line pressure is supplied to the control valve 102 by communicating with the line 109 extending to 2. 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 increased. Is adjusted according to the control pressure to obtain a predetermined fastening pressure,
Second hydraulic chamber 3 of deceleration brake 34 via line 110
4 ₂ and the deceleration brake 34 is engaged.

The direct coupling clutch 32 is provided in the first hydraulic chamber 3
2 ₁ is line 106, 5th shift valve 65, line 1
13, the direct coupling clutch control valve 101 and the line 111 communicate with the drain port of the fourth shift valve 64, and the second hydraulic chamber 32 ₂ is connected to the line 114.
It is in a released state by communicating with the drain port of the fifth shift valve 65 via. As a result, the shift stage of the auxiliary transmission 30 becomes a low speed stage where the engine brake operates, and the automatic transmission as a whole becomes the first speed where the engine brake does not operate.

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

The line pressure supplied to the control valve 78 is the first linear solenoid valve 80.
Is adjusted to a fastening pressure according to the control pressure supplied to the control port 78a via the line 81 from the line 1
It is supplied to the low reverse brake 29 via 27.
As a result, in addition to the forward clutch 23, the low reverse brake 29 is engaged, and the low speed stage in which the engine brake operates in the main transmission 20 is obtained.
Then, in the auxiliary transmission 30, the deceleration brake 34 is engaged as in the case of the above-described first speed in which the engine brake is not operated, so that the automatic transmission as a whole can obtain the first speed in which the engine brake is operated.

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

That is, the fourth ON- in the auxiliary transmission 30.
The OFF solenoid valve 74 is turned ON, and accordingly, the spool of the fourth shift valve 64 is positioned on the left side.
Therefore, 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 coupling clutch control valve 101 via the line 111, and the control is performed. The rising of the valve 101 is adjusted, and then the first hydraulic chamber 32 of the direct coupling clutch 32 is passed through the line 113, the fifth shift valve 65, and the line 106.
_Will be supplied to ₁ . As a result, the auxiliary transmission 30
As a result, the gear shift stage becomes a high speed stage, and as a result, the automatic transmission as a whole can obtain the second speed in which the engine brake does not operate or the second speed in which the engine brake operates.

Further, in the third speed, in the main transmission 20, the first to third ON-OFF solenoid valves 71 to 7 are provided.
3 is OFF, ON, ON, and the spools of the first to third shift valves 61 to 63 are connected to the right side, the left side,
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 the line 129 leading to the coast brake control valve 77 via the third shift valve 63. Communicate with. Therefore, the line pressure is supplied to the control valve 77, which is adjusted to a predetermined fastening pressure in accordance with the control pressure supplied from the first linear solenoid valve 80 through the line 81, and then, through 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, and supplies the 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 a fastening 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 as well, the medium speed stage in which the engine brake operates can be obtained.

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

In the 4th speed, the 4th and 5th ON-OFF solenoid valves 74 and 75 of the auxiliary transmission 30 are both turned ON from the state of the 3rd speed, and the 4th and 5th shift valves 64 and 65 are turned on. The spool is located on the left side, so that, as in the case of the above-described second speed, first, the line pressure is changed from the main line 42 through the line 107, the fourth shift valve 64, and the line 111 to the control valve 101 for the direct coupling clutch. Is supplied to the control valve 1
The start-up is adjusted at 01, and the predetermined tightening 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 coupling clutch 32.
₂ will be supplied. As a result, the direct coupling clutch 3
2 is engaged and the shift stage of the auxiliary transmission 30 becomes the high shift stage.
Then, since the main transmission 20 is set to the medium speed as in the case of the above-described third speed, the speed of the automatic transmission as a whole becomes the fourth speed.

Furthermore, in the fifth speed, the first to third ON-OFF solenoid valves 71 to 71 in the main transmission 20 are arranged.
73 is turned OFF, ON, and OFF, and the spools of the first to third shift valves 61 to 63 are located on the right side, the left side, and the right side. Therefore, the line 125 branched from the main line 42 passes through the first shift valve 61 and the line 13
3 and also to the line 134 communicating with the direct coupling clutch control valve 76 via the third shift valve 63, and therefore the 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 through the line 82 to engage the clutch 24. As a result, the main transmission 20
In, the forward clutch 23 and the direct coupling clutch 24 are engaged, and the shift speed becomes the high speed 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 includes the fourth and fifth ON-OFF solenoid valves 7 as in the case of the above-described fourth speed.
Since both gears 4 and 75 are in the ON state and the gear stage is set to the high gear stage, as a result, the automatic transmission as a whole can obtain the fifth gear.

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

Therefore, first, the line 125 branched from the main line 42, as in the case of the above-described fifth speed,
A line 134 communicating with the line 133 via the first shift valve 61 and further communicating with the direct coupling clutch control valve 76 via the third shift valve 63.
Therefore, the line pressure is supplied to the control valve 76. In this case, a line pressure is supplied to the port 76b at one end of the control valve 76 from the retreat line 53 through 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 directly supplied to the direct coupling clutch 24 via the line 82 without being reduced in pressure, and the direct coupling clutch 24 is fastened at a high fastening pressure.

Further, the retreat line 53 has an orifice 135 having a different throttle amount in the hydraulic oil supply direction and the hydraulic oil discharge direction.
The low reverse brake control valve 78 communicates with the control valve 78 through the line 136 having the above, the third shift valve 63, and the above-mentioned line 126, and the control valve 78 is the same as in the case of the first speed of the engine braking operation.
Supply line pressure to. In this case, the port 78b at one end of the control valve 78 has the retreat line 53
The spool of the control valve 78 is fixed to the left side in the drawing by introducing the line pressure by the line 86 branched from the line. Therefore, the above line 12
The line pressure supplied by 6 is directly supplied to the low reverse brake 26 without being adjusted by the control valve 78.
6 will be 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 auxiliary transmission 30, the fourth and fifth ON-OFF solenoid valves 74, 7 are provided.
Since both 5 are OFF, the gear stage is set to the low speed stage where the engine brake operates, and a reverse speed with a large reduction ratio can be obtained.

When the fastening pressure is supplied to the low reverse brake 26, hydraulic fluid is introduced from the line 136 to the fourth accumulator 90 via the line 137, so that the fastening pressure is maintained at a predetermined level. It will gradually rise after passing the shelf pressure.

In addition to the above structure, the hydraulic circuit 40 includes a lockup clutch 1 in the torque converter 10.
7, lock-up first and second shift valves 141 and 142, a lock-up control valve 143, a lock-up control ON-OFF solenoid valve 144, and a duty solenoid valve 145.
Is provided, and engagement control and release control of the lock-up clutch 17 and slip control for slipping the clutch 17 are performed.

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

Further, 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 that detects the rotation speed of the output side of the main transmission 20 (input side of the sub transmission 30), and a third rotation sensor 1 that detects the rotation speed of the output side of the sub transmission 30.
66 is connected. Then, the controller 16
0 indicates that these sensors 164 to 166 will be described later.
The gear ratios of the main transmission 20 and the auxiliary transmission 30 are calculated based on the signal from, 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 structure, but as is clear from Table 1 above, when shifting from the third speed state to the second speed and from the second speed state to the third speed. At the time of gear shifting, the gear ratios of the main transmission 20 and the sub transmission 30 simultaneously perform gear shifting operations in opposite directions, and the coast brake for engine braking is used during the former 3-2 gear shifting. 29 is released from the fastening state.

In this embodiment, the above 3-2
Gear shifting is executed as follows according to the flowchart shown in FIG.

That is, the controller 160 reads various signals in step S1 and then, in step S2, 3-
It is determined whether or not the value of the 2-shift flag F _3-2 is 1. Here, the 3-2 shift flag F _3-2 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 F _3-2 is not set to 1, the controller 160 proceeds from step S2 to step S3 and determines whether the 2-3 shift command is output. If it is determined that the 2-3 shift command is not output, the process proceeds to step S4 to determine whether the 3-2 shift command is output this time. Then, when the 3-2 shift command is output, the routine proceeds to step S5, where the 3-2 shift flag _F3-2 is set to 1, and then the routine proceeds to step S6 to perform the predetermined 3-2 shift control. While executing, it is determined in step S7 whether or not the 3-2 shift is completed, and when it is determined that the 3-2 shift is completed, the 3-2 shift flag _F3-2 is cleared to 0 in step S8. 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 shift down line forming the shift map, the 3-2 shift command is output. And
When the rate of change of the throttle opening is larger than a predetermined lower limit value, a predetermined torque demand control is executed.

In other words, the controller 160 discharges the engagement pressure of the coast brake 29 of the main transmission 20 and releases the engagement pressure of the 3-4 brake 28 at a predetermined level during, for example, slow acceleration in which the rate of change of the throttle opening is small. After the rack pressure is set, the fastening pressure is reduced at a predetermined pressure reducing gradient to reduce the main transmission 2
Downshift the 0 gear from the middle gear to the low gear.

Then, the deceleration brake 34 of the auxiliary transmission 30
The gear shift stage of the auxiliary transmission 30 is upshifted from the low gear stage to the high gear stage by discharging the engagement pressure of the above and supplying the engagement pressure to the direct coupling clutch 32. Auxiliary transmission 30 corresponding to the increase in the ratio
The second linear solenoid valve 103 controls the engaging operation of the direct coupling clutch 32 in the auxiliary transmission 30 so that the gear ratio of the second transmission is reduced.

That is, the controller 160 includes the first and the first transmissions arranged on the input side and the output side of the main transmission 20, respectively.
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 auxiliary transmission 30 is decreased at each time point as the increase of the gear ratio is calculated. The target gear ratio of the auxiliary transmission 30 is set. Then, the target gear ratio and the input side and the output side of the auxiliary transmission 30 respectively. The second linear solenoid valve described above 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 in a line, and the deviation is eliminated. The engagement operation of the direct coupling clutch 32 by 103 is feedback-controlled.

While the shifting operation from the 3rd speed to the 2nd speed is progressing in this way, the gear stage is returned to the original 3rd speed 2-3
When the shift command is output, the controller 160 executes the following control.

Returning to the flow chart 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 also coasts. With the brake 29 held in the released state, another friction element, 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 brought into the engaged state to return to the third speed state.

Then, in steps S12 and S13, it is determined whether the backup timer has timed out and the auxiliary transmission 30
When the backup timer has timed out or the switching operation of the auxiliary transmission 30 has ended, the process proceeds to step S14 to start the engagement operation of the coast brake 29 and 3 -2
The shift flag F _3-2 is cleared to 0.

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

According to this embodiment, the following effects 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 associated with 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, so that the gear shifting operation of the main transmission 20 is performed. Be started. Further, in the auxiliary transmission 30, the fastening pressure of the deceleration brake 34 is exhausted. Then, 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 engaging force of the direct coupling clutch 32 is feedback-controlled so that the gear ratio of the auxiliary transmission 30 increases in response to the decrease of the gear ratio of the main transmission 20.

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

Then, for example, when the switching operation to the low speed stage in the auxiliary transmission 30 is completed, the coast brake 2
The supply of the fastening pressure to 9 is started, and the brake 29
When they are fastened, they are in an embled state.

[0090]

As described above, according to the present invention, the main transmission and the sub transmission having the transmission mechanism that operates independently of each other are provided, and the friction element for engine braking is fastened at a predetermined shift speed. And an automatic transmission in which the main transmission and the sub-transmission simultaneously perform a shift operation at the time of a shift in which the predetermined shift stage and another shift stage in which the friction element for engine braking is released are switched. At the time of a gear shift in which a predetermined gear stage in which a friction element for engine braking is engaged is switched to another gear stage in which the friction element is released, the original predetermined gear stage is restored due to a reduction in engine load during the gear shift. When a shift request like this occurs,
Since the engaged state of the other friction elements of the main transmission and the auxiliary transmission will be returned to the state of the above-mentioned predetermined speed stage while the released state of the friction element for engine braking is maintained, a large shock is generated. Therefore, the gear shifting operation is prevented and the gear shifting operation is performed well.

In particular, according to the second aspect of the present invention, the main transmission and the sub-transmission are operated at the time of a shift in which the predetermined speed stage to which the engine braking friction element is engaged and the other speed stage to which the friction element is released are switched. In an automatic transmission in which a gear ratio change and a gear shift operation in the opposite direction are simultaneously performed, the gear shift operation of the sub-transmission proceeds while appropriately responding to the gear shift operation of the main transmission during the gear shift. Therefore, the shift shock is effectively reduced.

Moreover, 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 for returning the shift stage to the original shift stage where the friction element for the engine brake is fastened due to the reduction of the engine load, other friction is maintained while the released state of the friction element for the engine brake is maintained. Since the fastening state of the element is returned to the original state, complication of the control is avoided and the shock is greatly reduced.

[Brief description of drawings]

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

FIG. 2 is a cross-sectional view showing a structure of an auxiliary transmission in the same 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.

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

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

[Explanation of symbols]

 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 second 3 rotation sensor

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Ryori Mizobe 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Mazda Motor Corporation

Claims (2)

[Claims] 1. A main transmission and an auxiliary transmission having a transmission mechanism that operates independently of each other, the friction element for engine braking being configured to be engaged at a predetermined shift speed, and the predetermined shift. In an automatic transmission in which a main transmission and a sub transmission simultaneously perform a gear shift operation during a gear shift in which a gear stage and another gear stage in which the friction element for engine brake is released are switched, At the time of shifting to another shift stage in which the friction element is released, after the release operation of the friction element for engine braking and the shift operations of the main transmission and the sub-transmission are started, the shift stage is set by the reduction of the engine load. When a shift request for returning to a predetermined shift stage is made, the engagement state of the other friction elements of the main transmission and the auxiliary transmission while maintaining the released state of the engine brake friction element. A control device for an automatic transmission, comprising: control means for returning to the state of the above-mentioned predetermined shift speed, and thereafter starting the engagement operation of the friction element for engine braking. 2. A main transmission and a sub-transmission, each of which has a transmission mechanism that operates independently of each other, is configured so that a friction element for engine braking is engaged at a predetermined shift stage, and the predetermined shift is provided. In an automatic transmission in which a gear ratio change between the main transmission and the sub-transmission is performed at the same time during a gear shift in which the gear and the other gear that releases the friction element for engine braking are switched, Feedback means for feedback controlling the engaging force of a predetermined friction element on the auxiliary transmission side is provided so that the gear ratio of the auxiliary transmission changes in the opposite direction corresponding to the change of the gear ratio of the main transmission. After the release operation of the friction element for the engine brake and the shift operation of the main transmission and the sub-transmission are started during the shift from the predetermined shift stage to another shift stage where the friction element for the engine brake is released. When a shift request for returning the shift stage to the predetermined shift stage is generated due to a reduction in engine load, the other friction of the main transmission and the auxiliary transmission is maintained with the released state of the friction element for engine braking being maintained. A control device for an automatic transmission, comprising: a control means for returning the engagement state of the element to the state of the predetermined shift stage, and thereafter starting the engagement operation of the friction element for engine braking.