JPH06193729A - Control device for shift-by-wire automatic transmission - Google Patents

Abstract

PURPOSE:To prevent additive action of response delay factors in changing ranges by recognizing an instruction signal in case of changing a range changing valve by actuation of an actuator through a transmission mechanism in which specified play is set. CONSTITUTION:In a shift-by-wire automatic transmission, an actuator 1 such as a motor is driven by an electric signal based on switch operation, and changing action of a range changing valve 3 is performed by its power through a transmission mechanism 2 including a worm, worm wheel, etc., in which specified play is set. In this case, when the switch operation is made, the actuator 1 is initially actuated to reduce the play of the transmission mechanism 2 by an initial drive instruction means 4. After initial actuation, if the range changing valve 3 is in a condition of being capable of changing action or not is determined by a shift determining means 5, and when this determination is YES, the actuator 1 is set to be actuated further to be continuously actuated by a shift instruction means 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shift-by-wire automatic transmission that switches a driving range such as a parking range and a drive range based on a switch operation.
In particular, it relates to a device for controlling the switching of the driving range.

[0002]

2. Description of the Related Art As is well known, an automatic transmission for a vehicle is constructed by appropriately engaging a friction engagement device such as a clutch or a brake in a gear train on the basis of a traveling state such as a vehicle speed or a throttle opening. Although it is configured to set a predetermined shift speed, these ranges are selected by the manual shift valve when the parking state, the setting of the reverse speed, or the forward speed is limited to the predetermined low speed. In the past, this manual shift valve switching operation was generally configured to be performed by a lever provided in the driver's seat, but recently, by operating the actuator by a switch operation, the manual shift valve is switched by the actuator. So-called shift-by-wire automatic transmissions have been developed to operate.

An actuator for range change in an automatic transmission of this kind has a structure except for a parking range.
Since only a linear movement of the valve is required, a particularly large output is not required in that case, but for the parking range, it is necessary to drive a parking mechanism that directly blocks rotation of the output shaft by mechanical means, Large output is required. Therefore, if a large-capacity actuator is used as the actuator, the range can be swiftly switched including the switching to the parking range.
However, the actuators that can be mounted are limited by factors such as space and cost, and in reality, it is often not possible to employ actuators that satisfy swiftness.

Further, in the shift-by-wire automatic transmission, the range can be easily switched by operating the switch, and since an electric means is interposed between the operation by the passenger and the actual range switching, a malfunction occurs. It is desirable to configure so as to prevent
In the invention described in Japanese Patent Publication No. 260, the presence or absence of the fail is confirmed by matching the position signal for selecting the range with the signal indicating the traveling direction.

Further, when the manual shift valve is switched by an actuator, it is difficult to exactly match the operation amount of the actuator with the required stroke amount of the manual shift valve, and therefore the actuator and the manual shift valve are connected. The transmission mechanism such as the link mechanism is provided with play.
That is, a member having a concave portion corresponding to each range position of the manual shift valve is provided so as to operate integrally with the manual shift valve, and means for elastically engaging the concave portion is arranged at a predetermined position. The manual shift valve is operated by operating the manual shift valve at the same time as the member having the recess, and by indexing the final position of the manual shift valve with the elastic engaging means in the recess. Are moved within the play range.

[0006]

As described above, the drive range switching mechanism in the shift-by-wire automatic transmission is as follows.
In addition to the fact that an actuator with a sufficiently large output cannot always be used, it is necessary to check the range switching instruction signal, and because the transmission mechanism from the actuator to the manual shift valve is set to play, The delay in the processing system and the mechanical transmission system appears as a delay in the operation of switching the traveling range. That is, in the conventional device, the delay factor of the signal system and the delay factor of the mechanical system act additively, and the response delay of the range switching becomes large.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a control device capable of improving the response delay of range switching in a shift-by-wire automatic transmission.

[0008]

The present invention is characterized in that it has the structure shown in FIG. 1 in order to achieve the above object. That is, according to the present invention, the transmission mechanism 2 in which a predetermined play is set by operating the actuator 1 by an electric signal based on a switch operation.
In a control device for a shift-by-wire automatic transmission that switches the range switching valve 3 via a switch, an initial drive instruction to operate the actuator 1 so as to close the play when an electrical signal based on the switch operation is output. Means 4, shift determining means 5 for determining whether or not the range switching valve 3 is in a switching operation state even after the operation of the actuator 1 based on the instruction of the initial drive instructing means 4, and the shift determination thereof. When the means 5 determines that the range switching valve 3 is in the switching operation state, the shift instruction means 6 for further continuing the operation of the actuator 1 is provided.

[0009]

The automatic transmission to which the present invention is applied is a shift-by-wire automatic transmission in which the traveling range is switched by operating a switch. When the desired traveling range is selected by operating the switch, the actuator 1 operates and the transmission is performed. The range switching valve 3 is switched via the mechanism 2. In that case, when an electrical signal based on the switch operation is output,
When the traveling range instructed by the switch operation is different from the traveling range actually set at that time, the initial drive instructing means 4 operates the actuator 1 in the direction for setting the instructed traveling range. This is an operation for closing the play in the power transmission mechanism 2, and the travel range is not immediately switched. After this so-called backlash reduction, the shift determination means 5 determines whether or not the range switching valve 3 is in a state capable of switching to the instructed travel range, and switches to the instructed travel range. If so, the shift instruction means 6 causes the actuator 1 to continue operating. At this point, the play in the transmission mechanism 2 has been eliminated, so that the range switching valve 3 is immediately switched by the operation of the actuator 1. Therefore, it is possible to confirm the instruction signal while the initial drive instruction means 4 is operating the actuator 1, and the play is eliminated during the confirmation operation, so that one of the delay factors is eliminated. It is possible to prevent the delay factor from acting additively.

[0010]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 2 is a perspective view showing an embodiment of the present invention, in which a motor 1 is used as an actuator for switching a manual shift valve 10 which is a range switching valve.
This is an example using 1. That is, the manual shift valve 10 is a spool-type valve similar to a manual shift valve in a conventional automatic transmission that manually switches the range, and is supplied with a line hydraulic pressure that is a source pressure for control and driving, and shift position. A predetermined friction engagement device (not shown) in a route corresponding to each traveling range according to
Is configured to supply hydraulic pressure to.

A control shaft 12 forming a part of a transmission mechanism for transmitting the driving force of the motor 11 to the manual shift valve 10 is arranged in a direction orthogonal to the axis of the spool of the manual shift valve 10. A detent lever 13 is fixed to the control shaft 12 so as to rotate integrally. The detent lever 13 is a substantially fan-shaped plate-shaped member, and a plurality of recesses 14 are formed in the arc-shaped outer peripheral portion thereof. A leaf spring 16 having a roller 15 engaged with the recess 14 at the tip is fixed to a predetermined fixing portion in a cantilever manner, and the roller 15 is forced to one of the recesses 14 by the elastic force of the leaf spring 16. Are engaged with each other. These recesses 14 and rollers 15 are arranged corresponding to the setting positions of each range in the manual shift valve 10. Therefore, by fully engaging one of the recesses 14 with one of the recesses 14, The manual shift valve 10 is set to the travel range position corresponding to.
That is, these detent lever 13 and roller 1
A detent mechanism 17 is constituted by 5 and the leaf spring 16.

The automatic transmission targeted in this embodiment is also provided with a parking lock mechanism 18 for stopping the rotation of the output shaft by a mechanical means in the parking range, and an L-shaped link 19 for operating this. It is connected to the detent lever 13. Parking lock mechanism 18
As in the conventional general automatic transmission, the parking lock pole 22 is engaged with a member that rotates integrally with the output shaft, for example, an uneven portion 21 formed on the outer peripheral portion of a predetermined ring gear 20 for output. It is configured to stop the rotation of the shaft. The L-shaped link 19 that operates the parking lock mechanism 18 is a member that is bent at a substantially right angle, and has its base end fixed to the detent lever 13 and its front end that is attached to the parking lock pole 22 by a ring gear. The L-shaped link 19 extends to a position opposite to 20 and has a tapered cone-shaped cam 2 at the tip of the L-shaped link 19.
3 is fitted in such a manner that it can be moved back and forth and is pressed by the spring 24 in the tip direction. That is, as the L-shaped link 19 is moved forward, the cam 23 is pressed by the spring 24. As a result, the cam 23 pushes up the parking lock pole 22 to the ring gear 20 side, so that the parking lock pole 22 engages with the ring gear 20. In this case, the rotation of the output shaft is mechanically blocked.

A worm 26 is provided on the output shaft 25 of the motor 11, and a worm wheel 27 meshing with the worm 26 is attached to the control shaft 12.
3 shows the control shaft 12 and the worm wheel 27.
It is a figure showing the connected state in the direction of rotation with, and the end 28 of the control shaft 12 is formed in a rectangular cross section, and the boss of the worm wheel 27 into which it is inserted has a width and a length. In each case, a substantially hourglass-shaped engagement hole 29 larger than the rectangular cross section 28 of the control shaft 12 is formed. Therefore, a predetermined play amount δ is set between the rectangular cross section 28 and the engagement hole 29 in the rotation direction.

The means for controlling the motor 11, that is, the means for selecting the traveling range is constructed as follows. That is, a DC motor is used as an example of the motor 11, and an electronic control unit 30 mainly including a microcomputer for controlling the motor 11 includes a parking range “P”, a reverse range “R”, a neutral range “N”, A range selection switch 31 having switches corresponding to the drive range “D”, the two ranges “2”, and the L range “L” is connected. Further, an actuator position sensor 32 and a valve position sensor 33 are connected to the electronic control unit 30 via an A / D converter 34. That is, when a predetermined travel range is selected by operating the range selection switch 31, a drive signal in the direction for setting the selected travel range is output from the electronic control unit 30 to the motor 11, and each sensor 32 is also provided. , 33, a feedback signal is input to the electronic control unit 30, and when the motor 11 rotates to a position where the selected traveling range is set, the output of the drive signal to the motor 11 is stopped.

At the time of setting the traveling range by the above-mentioned device, the control of the confirmation of the instruction signal and the cancellation of the play amount δ are first performed, and subsequently, the manual shift valve 1
The motor 11 is controlled to move 0 to the selected travel range position. FIG. 4 shows a control for canceling the play amount δ in the transmission mechanism among these controls. When the range selection switch 31 is operated, the selected range and the already set range are first determined. It is judged whether or not they are the same (step 1), and if they are the same, this routine is exited.
Then, it is determined whether the selected range is being confirmed. This is a control for judging that the reverse range R is ineligible and prohibiting its setting when the reverse range R is selected while the vehicle is traveling forward at a vehicle speed equal to or higher than a predetermined value. In the case of "yes", the routine proceeds to step 3, where it is judged whether or not the manual shift valve 10 is within the predetermined traveling range position. That is, the position allowed for the spool of the manual shift valve 10 to set a predetermined traveling range is set to a certain width, and if the spool position is within the range, the manual shift valve 10 Is set to a predetermined traveling range. Therefore, if the determination result in step 3 is "yes", it means that the transmission mechanism is playing, so in step 4, control for driving the motor 11 to the selected range side is executed, and then the control process is executed. To return.

As a result of driving the motor 11 as described above,
If the position of the spool of the manual shift valve 10 deviates even slightly from the set range of the predetermined traveling range, the judgment result of step 3 becomes "No". In this case, therefore, the control for stopping the motor 11 is executed in step 5. To do. That is, in this case, since the manual shift valve 10 has been operated because the play in the transmission mechanism has been reduced, the motor 11 is stopped. While performing such initial drive control of the so-called motor 11,
When the confirmation of the selected range is completed, the determination result of step 2 becomes "NO", the control of step 4 is executed, and the motor 11 is driven in the direction for setting the selected range.

That is, in the above control device, when the traveling range is selected, the selected range is confirmed, and at the same time, the motor 11 is driven and selected so as to close the play in the transmission mechanism. After confirming the range, the manual shift valve 10 is immediately operated toward the selected traveling range. In other words, the confirmation of the selected travel range and the elimination of the play amount δ in the transmission mechanism proceed at the same time, so that the operation delay when the travel range is switched is eliminated or shortened.

FIG. 5 shows an example in which the control for eliminating the play amount δ in the transmission mechanism, that is, the so-called backlash reduction control, is performed during non-shift control such as after the completion of the switching of the traveling range. That is, first, it is judged whether or not the traveling range selected by the range selection switch 31 is the same as the traveling range actually set in the automatic transmission (step 10), and these traveling ranges become the same. If so, it is determined in step 11 whether the range switching has been completed. When the range switching control has been completed, it is determined in step 12 whether the flag FL is "1". This flag FL is a flag that is set to "1" during execution of the backlash reduction control, as will be described later, and is initially set to "0".
Initially, the determination result of step 12 is "No", and the process proceeds to step 13. In step 13, it is determined whether the flag FP is "0". This flag FP is a flag that is set to "1" when the valve position sensor 33 detects a change in the range position of the manual shift valve 10, and is initially set to "0". The result of the judgment is "yes", and the routine proceeds to step 14 where the play reduction control is executed.

This play reduction control is a control for slightly operating the motor 10 in order to eliminate the play (play) that is set or unavoidably present in the transmission mechanism from the motor 11 to the manual shift valve 10. The driving direction of the motor 10 is a direction for setting a traveling range that is frequently set. Then, in step 14, the flag FL is set to "1" and then the process returns.

In the state where the play is controlled in this manner, the judgment result of step 3 becomes "yes". In this case, therefore, the routine proceeds to step 15 where the valve position sensor 33 causes the manual shift valve 10 to operate. It is determined whether a change in position has been detected. The result is "yes"
If so, it means that the manual shift valve 10 has been operated in accordance with the operation of the motor 11, and this is the state in which the play amount is naturally eliminated, so the routine proceeds to step 16 and the stop control of the motor 11 is executed, The flag FL is reset to zero and the flag FP is set to "1".
If the result of the determination in step 15 is "no", it means that there is still play in the transmission mechanism. Therefore, in step 17, the flag FP is set to "0" and the process returns.

On the other hand, if the result of determination in step 10 is "No" because the selected driving range and the driving range set in the automatic transmission are different,
When the shift control for switching the traveling range is completed and the result of the determination in step 11 is "NO", the process proceeds to step 18 to reset the flag FL to zero and then returns. If the determination result in step 13 is "NO", the manual shift valve 10 does not move even if the motor 11 operates, and the play has not yet been resolved. Continue driving.

Therefore, if the control shown in FIG. 5 is performed, the play amount in the transmission mechanism is eliminated immediately before the switching of the traveling range, so that the switching operation of the manual shift valve 10 can be performed simultaneously with the driving of the motor 11. It is started, and the delay of range switching is shortened.

The present invention is not limited to the above embodiment, the actuator for driving the manual shift valve 10 may be other than a motor, and the transmission mechanism may be the detent mechanism described above. It may not be included.

[0024]

As described above, according to the control device of the present invention, the actuator is operated so as to eliminate the play amount in the transmission mechanism during the confirmation of the instruction signal for switching the traveling range. Since the closing and the signal confirmation proceed at the same time, the time required for controlling either one does not appear as the delay time of the traveling range, and the traveling range switching control can be speeded up.

[Brief description of drawings]

FIG. 1 is a block diagram showing a basic configuration of the present invention.

FIG. 2 is a perspective view schematically showing an embodiment of the present invention.

FIG. 3 is a diagram for explaining a play amount according to an embodiment of the present invention.

FIG. 4 is a flowchart showing a control routine for canceling the play amount in the embodiment of the present invention.

FIG. 5 is a flowchart showing another example of a control routine for canceling the play amount by the control device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Actuator 2 Transmission mechanism 3 Range switching valve 4 Initial drive instruction means 5 Shift determination means 6 Shift instruction means

Claims (1)

[Claims] 1. A control device for a shift-by-wire automatic transmission, wherein an actuator is operated by an electric signal based on a switch operation to switch a range switching valve via a transmission mechanism having a predetermined play. Initial drive instruction means for operating the actuator so as to close the play when an electric signal based on the switch operation is output, and the range even after the operation of the actuator based on the instruction of the initial drive instruction means is completed. Shift determining means for determining whether or not the switching valve is in a switching operation state, and further operating the actuator when the shift determination means determines that the range switching valve is in a switching operation state. Shift-by-wire comprising: The control device of the dynamic transmission.