JPH10103458A - Gear shift controller of automatic transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To smoothly perform a gear shift in a manual mode by an automatic transmission provided with a drift on ball. SOLUTION: This controller is provided with an automatic transmission 10 provided with a plurality of gear shift stages, a frictional fastening means 61 selecting each gear shift stage, a drift on ball 30 arranged on the frictional fastening means 61, a means 52 detecting the operation state of a vehicle according to a speed VSP and the opening TVO of an accel, a gear shift stage setting means 53 setting the gear shift stage of the automatic transmission 10 and a line pressure setting means 54 setting line pressure according to the operation state of the vehicle and a gear shift mode switching means 50 switching an automatic gear shift mode and a manual mode. The controller is provided with a gear shift inhibition means 55 inhibiting a gear shift in an area where closing valve pressure of the drift on ball 30 exceeds line pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shift control device for an automatic transmission having an automatic shift mode and a manual mode, and more particularly to a manual mode for an automatic transmission using a drift-on ball for an automatic shift mechanism. is there.

[0002]

2. Description of the Related Art As disclosed in Japanese Patent Application Laid-Open No. 5-60206, an automatic transmission employed in a vehicle is conventionally known which comprises a gear mechanism such as a planetary gear, a clutch and a brake. Thus, the gear (gear ratio) is automatically changed according to operating conditions such as the vehicle speed VSP and the throttle opening TVO (or accelerator opening).

[0003] In addition, in the automatic transmission as described above, in addition to an automatic shift mode in which a gear position is automatically determined according to operating conditions, a predetermined predetermined speed is set similarly to a conventional manual transmission. There are some known manual modes that select a gear position according to a driver's operation. For example, "Quarterly MOVE 1995 SPRING"
01 (published by San-Ei Shobo on April 28, 1995), pages 123 and 128, are known which selectively switch between the automatic shift mode and the manual mode with one shift lever.

[0004] This is usually the "P" of the shift switch.
In addition to the "R", "N", and "D" shift positions, an UP and DOWN switch is provided for the shift switch as a manual mode of the automatic transmission, and the relative shift is performed according to a driver's operation of a shift lever or the like. Change the ratio,
By operating the shift lever from the "D range" which is the automatic transmission mode to the manual mode side and operating to the UP or DOWN position, it is possible to set any gear ratio as in the conventional manual transmission. Is what you do.

When the shift lever is operated to the "UP" side,
While commanding an upshift to an automatic transmission, similarly operating the shift lever to "DOWN" commands a downshift and changing the speed ratio relative to the current speed ratio (or shift position). It is.

[0006]

By the way, in the automatic transmission provided with the gear mechanism and the clutch mechanism as described above,
The on / off of a power transmission path of a gear mechanism or the like is controlled by a multi-plate clutch 23 having a rotating hydraulic piston 22 as shown in FIG. 7. In order to prevent the release failure of the multiple disc clutch 23, a drift-on ball 30 is provided as an exhaust pressure valve.

[0007] In accordance with the line pressure of the piston chamber 22A supplied by the control valve 20 via the hydraulic circuit 21,
The piston 22 interrupts the multi-plate clutch 23,
The piston 22 has a communication hole 24 for controlling hydraulic pressure in the piston chamber 22A and selectively discharging hydraulic oil in the piston chamber 22A to the oil chamber 23A on the multi-plate clutch 23 side, and a drift-on ball. 30 is provided. The drift-on ball 30 has a piston chamber 22A and an oil chamber 23A.
8 (A) to 8 (C), the hydraulic oil in the piston chamber 22A when the multi-plate clutch 23 is engaged, as shown in FIGS. On the other hand, when the multi-plate clutch 23 is released, the hydraulic oil in the piston chamber 22A is quickly discharged to the oil chamber 23A,
This prevents dragging of the multi-plate clutch during shifting.

However, in the conventional automatic transmission having a drift-on ball, the line pressure for controlling the piston 22 is set in accordance with the throttle opening TVO (or the amount of depression of the accelerator pedal) and the vehicle speed VSP. In a region where the degree TVO is small, the speed change shock is reduced by setting the vehicle speed VSP to be smaller with an increase in the vehicle speed VSP. However, the hydraulic pressure for closing the drift-on ball 30 to engage the multi-plate clutch 23 ( Hereinafter, D
And OB valve closing pressure), as indicated by the broken line in FIG. 9, since the circle center oil pressure increases with increasing vehicle speed VSP (alpha engine speed), the DOB closed in the drawing during a time T ₁ after The pressure becomes larger than the line pressure, and the multi-plate clutch 23 cannot be fastened. Therefore, in the automatic transmission mode as shown in FIG.
When used as a clutch for switching the speed, an upshift line from the second speed to the third speed should be set so as to avoid the above-mentioned region where DOB valve closing pressure> line pressure (region A in FIG. 10). However, in an automatic transmission having a manual mode in addition to the automatic transmission mode as described above, when the driver performs an upshift from the second to third gear in the region A, the DOB valve closing pressure is reduced. Is insufficient, the multi-plate clutch 23 is not engaged, and the gear shift cannot be performed. If the line pressure is increased to solve this problem,
→ Manual shift to 3rd gear is possible, but vehicle speed VS
There has been a problem that the shift shock in the region where P is large is excessive and the drivability is reduced.

In view of the above, the present invention has been made in view of the above problems, and in an automatic transmission having a shift mechanism with a drift-on ball, an automatic transmission capable of adopting a manual mode while preventing an increase in shift shock. It is an object of the present invention to provide a shift control device.

[0010]

According to a first aspect of the present invention, as shown in FIG. 11, an automatic transmission 10 having a plurality of shift speeds and a frictional engagement for selectively switching a driving force to the plurality of shift speeds are provided. Means 61, a drift-on ball 30 provided in the friction fastening means 61, means 52 for detecting a driving state of the vehicle according to at least a vehicle speed VSP and an opening degree TVO of an accelerator pedal, and a detected driving state of the vehicle. Speed setting means 53 for setting the speed of the automatic transmission 10 in accordance with the vehicle speed; line pressure setting means 54 for setting the line pressure of the automatic transmission 10 in accordance with the detected driving state of the vehicle; 10 in a shift control device for an automatic transmission, the shift control device including a shift mode switching unit 50 for selectively switching between an automatic shift mode and a manual mode. When becomes over de comprises shift prohibiting means 55 for valve closing pressure of the drift-on ball 30 prohibits the shift of the region in excess of line pressure.

[0011] In the second invention, as shown in FIG.
An automatic transmission 10 having a plurality of gears; and a frictional engagement means 61 for selectively switching a driving force to the plurality of gears.
A drift-on ball 30 provided in the frictional engagement means 61, and means 52 for detecting a driving state of the vehicle according to at least the vehicle speed VSP and the opening degree TVO of the accelerator pedal.
And a speed setting means 53 for setting the speed of the automatic transmission 10 according to the detected driving state of the vehicle, and a line pressure for setting the line pressure of the automatic transmission 10 according to the detected driving state of the vehicle. An automatic transmission including a setting unit 54, a shift mode switching unit 50 for selectively switching the automatic transmission mode between the automatic transmission mode and the manual mode, and a manual transmission unit 51 for instructing an upshift or a downshift in the manual mode. In the shift control device of the transmission, when the shift mode switching means 50 is set to the manual mode, the shift speed setting means 53 is increased before the valve closing pressure of the drift-on ball 30 exceeds the line pressure. An auxiliary transmission means 56 for instructing a shift is provided.

According to a third aspect of the present invention, in the second aspect, as shown in FIG. 12, the auxiliary speed change means 56 is a speed detection means for detecting a closing speed of the accelerator pedal from an opening degree of the accelerator pedal 59. 60, and a shift command canceling means 57 for canceling the upshift command when the closing speed of the accelerator pedal exceeds a predetermined value.

According to a fourth aspect of the present invention, in the second aspect of the present invention, as shown in FIG. A downshift canceling means 58 for canceling the downshift command when the shift speed of the vehicle approaches a region where the valve closing pressure of the drift-on ball 30 exceeds the line pressure.

[0014]

Therefore, in the first invention, the driver can arbitrarily select the gear position in the manual mode. However, in the case where the drift-on ball is employed as the friction fastening means constituting the speed change mechanism, the first invention is not limited to the above. As in the conventional example, there is a region where the valve closing pressure of the drift-on ball is larger than the line pressure. Even if there is a shift command in this region, the operation of the frictional engagement means cannot be reliably performed. By prohibiting gear shifting within the vehicle and maintaining the gear at that time,
Even if a manual mode is added to an automatic transmission that employs a drift-on-ball as the friction fastening means, the fastening and release of the friction fastening means can be reliably performed, and a smooth shifting operation can be ensured.

According to the second aspect of the present invention, the upshift is automatically performed while the vehicle is in the manual mode before the vehicle enters the manual mode, so that the valve closing pressure of the drift-on ball becomes larger than the line pressure. Without entering the area, when the driver instructs the upshift or downshift with the manual transmission means, the friction fastening means is always and reliably engaged,
Release can be performed, and the operability in the manual mode of the automatic transmission using the drift-on ball as the friction fastening means can be improved.

According to a third aspect of the present invention, when the closing speed of the accelerator pedal exceeds a predetermined value, the automatic upshift is released even if the closing pressure of the drift-on ball exceeds the line pressure. Therefore, if the driver releases the accelerator pedal when entering a corner, the driver can release the accelerator pedal to apply the engine brake and run smoothly. The operability of the automatic transmission can be further improved.

According to a fourth aspect of the present invention, when the driver issues a downshift command using the manual shifting means, the downshift is performed when the shift stage after the downshift approaches a region where the valve closing pressure of the drift-on ball exceeds the line pressure. Cancel the order,
In order to maintain the gear stage at that time, in the manual mode of the automatic transmission employing the drift-on ball as the friction engagement means, the engagement and release of the friction engagement means can be reliably performed even on the downshift side, and smooth The shifting operation can be ensured.

[0018]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows an automatic shift mode in which the shift speed (or gear ratio, hereinafter the same) is automatically changed according to the driving state of the vehicle, and an optional shift speed can be selected according to the driver's operation. 1 shows an automatic transmission provided with a manual mode. An automatic transmission 10 connected to an engine 11 changes a gear ratio in accordance with a command from a shift control controller 1. The speed is changed to a gear corresponding to the gear position instructed by the shift controller 1.

This automatic transmission 10 is provided with a drift-on ball 30 in the transmission mechanism, similarly to FIGS.
And a multiple disc clutch 23 (friction fastening means), and selectively engages the multiple disc clutch 23 according to the line pressure from the control valve 20 as the line pressure control means. The multi-plate clutch 23 switches between the second speed and the third speed in the same manner as the conventional example. The multi-speed clutch 23 is in the third speed when the multi-plate clutch 23 is in the engaged state, and is in the disengaged state in the second speed.

The shift control controller 1 for controlling the control valve 20 and the like is mainly composed of a microcomputer, and as shown in FIG. 1, a shift switch 2 corresponding to an operation of a shift lever 3 operated by a driver. The automatic shift mode and the manual mode are switched in response to a signal from the vehicle. In the automatic shift mode, the vehicle speed VSP from the vehicle speed sensor 7 and the opening TV of the throttle valve (not shown) from the throttle opening sensor 6 are used as driving conditions of the vehicle.
O is read, the gear position is set based on the shift map as shown in FIG. 10 of the conventional example, and the gear position GEAR is instructed to the automatic transmission 10.

In order to select one of these shift modes, the selector switch 2 of the shift lever 3 has an "H" type gate as shown in FIG. A UP switch 4 ("+" in the figure) and a DOWN switch 5 ("-" in the figure) for performing manual shifting, and the shift lever 3 is operated from the D range position in FIG. 1 to the left side in the figure. Thus, the shift mode is switched from the automatic shift mode to the manual mode.

In this manual mode, the shift speed is sequentially changed relatively in accordance with the stroke of the shift lever 3 in the front-rear direction (vertical direction in FIG. 1). When the shift lever 3 is operated to the "+" side, The automatic transmission 10 is instructed to upshift from the current gear position. Conversely, when the shift lever 3 is operated to the “−” side, the automatic transmission 1
0 is instructed to downshift from the current gear position.

Next, an example of the control performed by the shift control controller 1 is shown in a flowchart of FIG. 2 and will be described in detail with reference to this flowchart. This flowchart is executed every predetermined time, for example, every 10 msec.

First, in step S1, the shift mode selected by the driver is read from the signal of the selector switch 2 to determine whether or not the mode is the manual mode. Then, the process ends.

In FIG. 1, when the shift lever 3 is at the "D" position, the automatic shift mode is set, and when the shift lever 3 is at the "+" or "-" side, the shift mode is a manual mode in which the shift is manually performed.

Next, in step S2, it is determined whether or not the gear currently set in the automatic transmission 10 is the second speed.
If it is the second speed, the process proceeds to step S3, while if it is another speed, the process is terminated.

In step S3, it is determined from the state of the UP switch 4 whether an upshift has been instructed. If the upshift has been instructed, the process proceeds to step S4. If not, the process ends. I do.

In step S4, it is determined whether or not the read throttle opening TVO and vehicle speed VSP are greater than a predetermined shift prohibition line from second speed to third speed.

The shift prohibiting connection to this 2 → 3 speed is set as shown in FIG. 3, the left region than in the drawing shift prohibiting lines, drift on as time T less than ₁ shown in FIG. 9 An area where the valve closing pressure of the ball 30 is lower than the line pressure and the valve of the drift-on ball 30 can be closed by the line pressure is an area where the multiple disc clutch 23 can be securely engaged. On the other hand, a hatched area A on the right side of the shift prohibition line
10, the valve closing pressure of the drift-on ball 30 is the line pressure, as in FIG.
2. The throttle opening TVO and the vehicle speed VSP are preset in accordance with the drift-on ball 30 and the like.
It is set to change according to.

If the vehicle speed VSP is higher than the second-third speed shift prohibition line, the process proceeds to step S5, in which the upshift from the second speed to the third speed is prohibited, and the current second speed is maintained.
If the vehicle speed VSP is lower than the second-third speed shift prohibition line, the process proceeds to step S6 to start an upshift to the third speed.

In this way, by executing steps S1 to S6 at predetermined time intervals, if the vehicle speed VSP is higher than the second-third speed shift prohibition line even in the manual mode, shifting is prohibited and the second Keeping the speed, Figure 3
The shift in the area A where the DOB valve closing pressure indicated by the oblique line is larger than the line pressure can be prevented, and even if the manual mode is added to the automatic transmission 10 that employs the drift-on ball 30 in the transmission mechanism, The engagement and disengagement of the multiple disc clutch 23 can be reliably performed, and a smooth shift operation can be ensured.

FIG. 4 is a flow chart showing an example of control performed by the shift control controller 1 according to the second embodiment. As shown in FIG. 5, a shift inhibition line shown in the shift map of the first embodiment is shown in FIG. Is the automatic transmission line of the second to third speeds, while the DOB valve closing pressure is in the region A where it is higher than the line pressure.
A third-to-second speed shift prohibition line is provided to prohibit downshifting to the second speed, and the other configuration is the same as that of the first embodiment.

First, the control will be described. At step S1, it is determined whether or not the manual mode is set. At step S11, it is determined whether or not the current gear is less than the third gear. If speed), step S1
On the other hand, if the speed is higher than the third speed, the process proceeds to the processes after step S14.

In step S12, if the vehicle speed VSP is higher than the second-third speed shift line in FIG. 5, step S13
Thus, the shift is automatically made up to the third speed in the manual mode.

On the other hand, in step S14 where the current speed is 3rd speed or higher (here, 3rd speed or 4th speed), a downshift command to turn on the DOW switch 5 of the shift switch 2 and a downshift of 2nd speed or less It is determined whether the command is a shift command. If the command is a downshift command for the second speed or lower, the process proceeds to step S15. If the command is a downshift from the fourth speed to the third speed, the process proceeds to step S17.

In step S15, it is determined whether or not the vehicle speed VSP is higher than the third-speed to second-speed shift inhibition line shown in FIG.
If the vehicle speed VSP is higher than the shift prohibition line, the downshift to the second speed or lower is prohibited, and in step S16, the downshift up to the third speed or the third speed is maintained, and the process ends.

On the other hand, if the vehicle speed VSP is lower than the shift prohibition line, a downshift to the second speed or lower is performed in step S17, and the process ends.

Therefore, on the upshift side, a predetermined value 2 is set according to the throttle opening TVO and the vehicle speed VSP.
→ If the driver attempts to cross the 3rd speed shift line, the vehicle automatically shifts to the 3rd speed in the manual mode. Therefore, even if the driver issues an upshift, the upshift to the 4th speed is performed. And the DOB valve closing pressure is always equal to or lower than the line pressure, so that the multiple disc clutch 23 can always be connected and disconnected reliably, and always responds to the driver's shift request. It becomes possible.

As shown in FIG. 5, when the vehicle speed VSP is higher than the third to second speed shift prohibition line set in advance according to the throttle opening TVO and the vehicle speed VSP on the downshift side, the shift to the second speed is performed. If the downshift is performed, the throttle opening TVO may decrease or the vehicle speed VSP may increase, so that the vehicle may enter the area A shown in FIG. 5. By restricting the shift to, the DOB valve closing pressure can always be kept below the line pressure, and the operability of the automatic transmission 10 employing the drift-on ball 30 in the manual mode can be improved. .

FIG. 6 is a flow chart showing an example of the control performed by the shift control controller 1 according to the third embodiment. The flow chart shown in FIG. 6 of the second embodiment is provided between steps S12 and S13 in the flow chart shown in FIG. The second speed can be maintained even when the speed exceeds the automatic shift line from the second to the third speed shown in FIG. 5 according to the operation speed ΔTVO / ΔT of the throttle opening TVO (or the operation speed of the accelerator pedal). The other configuration is the same as that of the second embodiment.

In step S12, similarly to the above, the vehicle speed V
If SP exceeds the automatic shift line from second to third speed, step S2
1, the operation speed ΔTVO of the throttle opening TVO
/ Δt is read.

In step S22, if the throttle operation speed .DELTA.TVO / .DELTA.t is smaller than a predetermined negative value .alpha., The process proceeds to step S23. If not, the process proceeds to step S13 to perform the same operation as in the second embodiment. Then, the shift from the second gear to the third gear is automatically performed even in the manual mode.

Step 23 is a throttle operation speed Δ
In the case where TVO / Δt is equal to or greater than a predetermined value in the closing direction, that is, when the driver releases his / her foot from the accelerator pedal, in such a case, the driver may expect engine braking. Hold.

If an upshift command is detected in step S24, and if the current vehicle speed VSP is on the higher speed side than the 2 → 3rd speed automatic shift line, the process proceeds to step S26 to hold the 2nd speed or 1 → 2. By performing the upshift to the high speed, the shift in the area A shown in FIG. 5 is prohibited in the same manner as described above. Proceed to perform an upshift from second gear to third gear.

As described above, the vehicle speed VSP changes from 2 to 3 in FIG.
Even when the throttle operation speed ΔTVO / Δt is released from the accelerator pedal even when the throttle operation speed ΔTVO / Δt is on the higher speed side than the automatic speed change line, the second speed or the first speed can be maintained and the engine brake can be applied. This makes it possible to improve driving performance on mountain roads and curved roads.

In the above-described embodiment, the multi-plate clutch 23 for switching between the second speed and the third speed has been described. However, any frictional engagement means provided with the drift-on ball 30 can be applied to other speeds.

[Brief description of the drawings]

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

FIG. 2 is a flowchart illustrating an example of control performed by a shift control controller.

FIG. 3 shows a shift prohibition line from second to third speed in a second speed range in a manual mode according to a vehicle speed and a throttle opening.

FIG. 4 is a flowchart illustrating an example of control performed by a shift control controller according to the second embodiment.

FIG. 5 shows a shift prohibition line from 2 → 3rd speed and 3 → 2nd speed in the 2nd speed range in the manual mode according to the vehicle speed and the throttle opening.

FIG. 6 is a flowchart illustrating an example of control performed by a shift control controller according to the third embodiment.

FIG. 7 shows a conventional example, showing a clutch mechanism provided with a drift-on ball.

8A and 8B are cross-sectional views of main parts of a piston showing an operation of the drift-on ball, wherein FIG. 8A shows a fastening state, FIG. 8B shows an OFF state of the drift-on ball, and FIG. .

FIG. 9 is a graph showing a relationship between a valve closing pressure of a drift-on ball, a line pressure (a piston chamber pressure), and an engine speed.

FIG. 10 shows a shift map in an automatic shift mode according to a vehicle speed and a throttle opening.

FIG. 11 is a claim correspondence diagram corresponding to the first invention.

FIG. 12 is a claim correspondence diagram corresponding to any one of the second to fourth inventions.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Transmission control controller 2 Selector switch 3 Shift lever 4 UP switch 5 DOWN switch 6 Throttle opening sensor 7 Vehicle speed sensor 10 Automatic transmission 11 Engine 20 Control valve 21 Hydraulic circuit 22 Piston 23 Multi-plate clutch 22A Piston chamber 23A Oil chamber 24 Communication Hole 25 Taper portion 30 Drift-on ball 50 Shift mode switching means 51 Manual shifting means 52 Operating state detecting means 53 Shift speed setting means 54 Line pressure setting means 55 Shift inhibiting means 56 Auxiliary shifting means 57 Shift command canceling means 58 Downshift canceling means 59 accelerator pedal 60 speed detecting means 61 friction fastening means

Claims (4)

[Claims] An automatic transmission having a plurality of shift speeds; a friction engagement means for selectively switching a power transmission path to the plurality of shift speeds; and a drift-on ball provided in the friction engagement means. A means for detecting a driving state of the vehicle according to at least a vehicle speed and an opening degree of an accelerator pedal; a gear setting means for setting a gear of an automatic transmission according to the detected driving state of the vehicle; Automatic transmission having line pressure setting means for setting the line pressure of the automatic transmission according to the operating state of the automatic transmission, and shift mode switching means for selectively switching between the automatic transmission mode and the manual mode of the automatic transmission. In the control device, a shift for prohibiting a shift in a region where the valve closing pressure of the drift-on ball exceeds a line pressure when the shift mode switching unit is in a manual mode. Shift control apparatus for an automatic transmission characterized by comprising a stop means. 2. An automatic transmission having a plurality of shift speeds, a friction fastening unit for selectively switching a power transmission path to the plurality of shift speeds, and a drift-on ball provided in the friction fastening unit. A means for detecting a driving state of the vehicle according to at least a vehicle speed and an opening degree of an accelerator pedal; a gear setting means for setting a gear of an automatic transmission according to the detected driving state of the vehicle; Line pressure setting means for setting the line pressure of the automatic transmission in accordance with the operating state of the automatic transmission; shift mode switching means for selectively switching between the automatic transmission mode and the manual mode of the automatic transmission; A shift control device for an automatic transmission including a manual shift unit for instructing a downshift, wherein the shift mode switching unit is in a manual mode. Shift control apparatus for an automatic transmission characterized by comprising an auxiliary shift means the closing pressure of the drift-on ball for commanding previously upshift to the gear position setting means for entering the region beyond the line pressure. 3. The auxiliary shift unit includes: a speed detecting unit that detects a closing speed of the accelerator pedal based on an opening degree of the accelerator pedal; and an upshift command when the closing speed of the accelerator pedal exceeds a predetermined value. 3. A shift control device for an automatic transmission according to claim 2, further comprising a shift command canceling means for canceling the gear shift. 4. The method according to claim 1, wherein the shift stage after the downshift approaches a region where the valve closing pressure of the drift-on ball exceeds a line pressure when a downshift command is issued from the manual shifting unit. 3. The shift control device for an automatic transmission according to claim 2, further comprising a downshift canceling means for canceling the downshift command.