JP2943547B2 - Control device for shift-by-wire automatic transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shift-by-wire automatic transmission in which a travel range such as a parking range or a drive range is switched based on a switch operation.
More particularly, the present invention relates to a device for controlling switching of a traveling range.

[0002]

2. Description of the Related Art As is well known, an automatic transmission for a vehicle appropriately engages a friction engagement device such as a clutch or a brake in a gear train based on a running state such as a vehicle speed or a throttle opening. Although the gears are configured to be set to a predetermined gear, these ranges are selected by a manual shift valve when the parking state, the reverse gear, or the forward gear is limited to a predetermined low gear. Conventionally, the switching operation of the manual shift valve is generally performed by a lever provided in a driver's seat, but recently, by operating an actuator by a switch operation, the manual shift valve is switched by the actuator. A so-called shift-by-wire automatic transmission for operation has been developed.

[0003] Except for a parking range, an actuator for switching a range in an automatic transmission of this type includes:
Since only the valve is moved linearly, a particularly large output is not required in that case.However, as for the parking range, it is necessary to drive a parking mechanism that directly prevents rotation of the output shaft by mechanical means. Large output is required. Therefore, if a large-capacity actuator is used, range switching including switching to the parking range can be performed quickly.
However, actuators that can be mounted are limited by factors such as space and cost, so that in many cases, an actuator that satisfies quickness cannot be adopted in practice.

In the shift-by-wire automatic transmission, the range can be easily changed by operating the switch, and furthermore, since the electric means is interposed between the operation by the occupant and the actual range change, malfunction occurs. Is desirably configured so as to prevent the above.
In the invention described in Japanese Patent Publication No. 260, the presence or absence of a failure is confirmed by matching a position signal for selecting a range with a signal indicating a traveling direction.

Further, when the manual shift valve is switched by the actuator, it is difficult to accurately match the operation amount of the actuator with the required stroke amount of the manual shift valve. Therefore, the actuator is connected to the manual shift valve. The transmission mechanism such as the link mechanism has 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 with the concave portion is disposed at a predetermined position, The manual shift valve is operated by operating the member having the concave portion at the same time as the manual shift valve, and the final position of the manual shift valve is determined by engaging the elastic engaging means with the concave portion. Is moved within the play range.

[0006]

As described above, the traveling range switching mechanism in the shift-by-wire automatic transmission has the following features.
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 switching operation of the traveling range. That is, in the conventional device, there is a disadvantage that 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 a response delay of range switching in a shift-by-wire automatic transmission.

[0008]

According to the present invention, in order to achieve the above-mentioned object, the configuration shown in FIG. 1 is adopted. That is, according to the present invention, the transmission mechanism 2 having a predetermined play is set by operating the actuator 1 by an electric signal based on a switch operation.
In the control device of the shift-by-wire automatic transmission for switching the range switching valve 3 via the control unit, an initial drive instruction for operating the actuator 1 to reduce the play when an electric signal based on the switch operation is output. Means 4, a shift determining means 5 for determining whether or not the range switching valve 3 is in a state of performing a switching operation even after the operation of the actuator 1 based on the instruction of the initial drive instructing means 4, and a shift determination thereof A shift instructing means 6 for operating the actuator 1 more continuously when it is determined that the means 5 is in a state of performing the switching operation of the range switching valve 3.

[0009]

The automatic transmission to which the present invention is directed is a shift-by-wire automatic transmission in which the driving range is switched by operating a switch. When a desired driving range is selected by operating a switch, the actuator 1 operates to transmit power. 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 travel range designated by the switch operation is different from the travel range actually set at that time, the initial drive instructing means 4 operates the actuator 1 in a direction to set the designated travel range. This is an operation to reduce play in the transmission mechanism 2, and does not immediately switch the traveling range. After the so-called backlash reduction, the shift determination means 5 determines whether or not the range switching valve 3 is in a state in which the operation can be switched to the designated traveling range, and the range switching valve 3 is switched to the designated traveling range. If so, the shift instructing means 6 causes the actuator 1 to continue operating. At this time, since the play in the transmission mechanism 2 has been eliminated, 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 instructing means 4 operates the actuator 1, and the play is eliminated during the confirmation operation. It is possible to prevent the delay factor from acting additively.

[0010]

Next, an embodiment of the present invention will 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 No. 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 a range, and is supplied with a line hydraulic pressure serving as a source pressure for control and driving, and is provided with a shift position. A predetermined frictional engagement device (not shown) on a route corresponding to each traveling range according to
It is configured to supply hydraulic pressure to the vehicle.

A control shaft 12, which is 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 plate-like member having a substantially fan shape, and a plurality of concave portions 14 are formed in an arc-shaped outer peripheral portion thereof. A leaf spring 16 having a roller 15 attached to the tip of the recess 14 is fixed to a predetermined fixing portion in a cantilever manner, and the roller 15 is forced into one of the recesses 14 by the elastic force of the leaf spring 16. It is designed to engage with each other. The recess 14 and the roller 15 are arranged corresponding to the setting positions of the respective ranges in the manual shift valve 10. Therefore, when the roller 15 is completely engaged with any one of the recesses 14, the recess 14 is The manual shift valve 10 is set at 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 to which this embodiment is applied is also provided with a parking lock mechanism 18 for stopping the rotation of the output shaft in the parking range by mechanical means, and an L-shaped link 19 for operating the parking lock mechanism 18 is provided. It is connected to the detent lever 13. Parking lock mechanism 18
In the same manner as in a conventional general automatic transmission, a parking lock pawl 22 is engaged with a member that rotates integrally with an output shaft, for example, a concave / convex portion 21 formed on an outer peripheral portion of a predetermined ring gear 20 to output. It is configured to stop rotation of the shaft. The L-shaped link 19 for operating the parking lock mechanism 18 is a member bent at a substantially right angle, and its base end is fixed to the detent lever 13, and its front end is connected to the parking lock pawl 22 by a ring gear. The L-shaped link 19 has a tapered cone-shaped cam 2
3 is fitted so that it can move back and forth and is pressed in the distal direction by a spring 24. That is, the cam 23 is pressed by the spring 24 as the L-shaped link 19 is moved forward, and as a result, the cam 23 pushes the parking lock pawl 22 toward the ring gear 20, whereby the parking lock pawl 22 is engaged with the ring gear 20. In this case, the rotation of the output shaft is mechanically prevented.

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.
FIG. 3 shows the control shaft 12 and the worm wheel 27.
FIG. 9 is a view showing a connection state in the rotation direction with the end portion of the control shaft 12 having a rectangular cross-section, and a boss portion of the worm wheel 27 into which the end portion 28 is inserted has a width and a length. Each of them has a substantially hourglass-shaped engagement hole 29 which is larger than the rectangular section 28 of the control shaft 12. Therefore, a predetermined play amount δ is set between the rectangular 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 travel range, is configured as follows. That is, as the motor 11, a DC motor is used as an example, and the electronic control unit 30 mainly including a microcomputer for controlling the DC motor 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 device 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 is output from the electronic control unit 30 to the motor 11 in a direction to set the selected travel range, and each sensor 32 , 33, the feedback signal is input to the electronic control unit 30, and when the motor 11 rotates to the position where the selected travel range is set, the output of the drive signal to the motor 11 is stopped.

When the travel range is set by the above-described device, control for confirming the instruction signal and eliminating the play amount δ is performed first, and subsequently the manual shift valve 1 is controlled.
Control of the motor 11 for moving 0 to the selected travel range position is performed. FIG. 4 shows a control for eliminating the play amount δ in the transmission mechanism among these controls. When the range selection switch 31 is operated, first, the selected range and the already set range are changed. It is determined whether they are the same (step 1). If they are the same, the process exits from this routine. If they are not the same, step 2
To determine whether the selected range is being checked. This is a control for determining that the reverse range R is ineligible and prohibiting the setting when the reverse range R is selected while the vehicle is traveling forward at a vehicle speed higher than a predetermined speed. If "yes", the routine proceeds to step 3, where it is determined whether or not the manual shift valve 10 is within a predetermined travel range position. That is, a certain width is set at the position allowed for the spool of the manual shift valve 10 to set a predetermined travel range, and if the position of the spool is within the range, the manual shift valve 10 Is set to the predetermined travel range. Therefore, if the result of the determination in step 3 is "yes", it means that there is play in the transmission mechanism, and in step 4, control for driving the motor 11 to the selected range side 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 slightly deviates from the set range of the predetermined travel range, the result of the determination in step 3 becomes “NO”. In this case, control for stopping the motor 11 is executed in step 5. I do. That is, in this case, the motor 11 is stopped because the manual shift valve 10 was operated because the play in the transmission mechanism was reduced. While performing such initial drive control of the motor 11,
When the confirmation of the selected range is completed, the result of the determination in step 2 becomes “no”, the control in step 4 is executed, and the motor 11 is driven in a direction to set the selected range.

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

FIG. 5 shows an example in which the above-described control for eliminating the play amount δ in the transmission mechanism, that is, the so-called play reduction control, is performed during non-shift control such as after completion of switching of the traveling range. That is, first, it is determined whether or not the travel range selected by the range selection switch 31 and the travel range actually set in the automatic transmission are the same (step 10), and these travel ranges become the same. If so, it is determined in step 11 whether or not range switching has been completed. If the range switching control has been completed, it is determined in step 12 whether or not the flag FL is "1". This flag FL is a flag that is set to "1" during execution of the play for reducing the play as described later, and is initially set to "0".
At first, the determination result of step 12 is “no”, and the process proceeds to step 13. In step 13, it is determined whether or not 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 determination is "yes" and the flow proceeds to step 14 to execute the play reduction control.

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

In the state where the backlash reduction control is performed in this manner, the determination result of step 3 is "yes". In this case, the process proceeds to step 15 where the valve position sensor 33 sets the manual shift valve 10 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 along with the operation of the motor 11, which is a state in which the amount of play has been eliminated, so that the process 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, so the program returns after setting the flag FP to "0" in step 17.

On the other hand, if the result of the determination in step 10 is "NO" due to the difference between the selected travel range and the travel range set for the automatic transmission,
If the shift control for switching the traveling range is completed and the result of the determination in step 11 is "NO", the routine proceeds to step 18, where the flag FL is reset to zero, and the routine returns. If the result of the determination in step 13 is “NO”, the play has not yet been eliminated because the manual shift valve 10 does not move even if the motor 11 operates, Continue driving.

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

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 same as 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 amount of play in the transmission mechanism during the confirmation of the command signal for switching the traveling range. Packing and signal confirmation proceed at the same time, so that the time required for either control does not appear as a delay time of the traveling range, and the switching control of the traveling range can be speeded up.

[Brief description of the drawings]

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

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

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

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

FIG. 5 is a flowchart showing another example of a control routine for eliminating the amount of play 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 instructing means 5 Shift determining means 6 Shift instructing means

Claims (1)

(57) [Claims] 1. A control device for a shift-by-wire automatic transmission in which an actuator is operated by an electric signal based on a switch operation to switch a range switching valve via a transmission mechanism in which a predetermined play is set. Initial drive instructing means for operating the actuator to reduce the play when an electric signal based on the switch operation is output, and the range after completion of the operation of the actuator based on the instruction of the initial drive instructing means. Shift determining means for determining whether or not the switching valve is in the switching operation state; and further operating the actuator when the shift determining means determines that the range switching valve is in the switching operation state. Shift-by-wire comprising shift instruction means for causing The control device of the dynamic transmission.