JP3021857B2 - Control device for automatic transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an automatic transmission in which a plurality of travel ranges can be selected by electrical control.

[0002]

2. Description of the Related Art In an automatic transmission, a traveling range such as a forward range, a reverse range, or a neutral range is switched by switching a range switching valve (manual valve). Although the range switching valve is generally switched by manual operation, an automatic transmission having a configuration in which the switching is performed by electrical control has already been proposed.

[0003] For example, US Patent No. 4,817,471 discloses a control device for an automatic transmission in which a range switch valve of an automatic transmission is operated by a motor driven by electric control to switch to a plurality of range positions. I have.

Further, in this device, a predetermined play amount (play) is provided in a part of a link member for transmitting power from the motor to the range switching valve. Further, the range switching valve is positioned at a plurality of range positions by a detent mechanism. Therefore, even if the motor does not stop accurately at the target rotation position, the range switching valve is self-propelled within the range of the play amount by the function of the detent mechanism and is positioned at the target range position.

[0005]

However, in the above-mentioned prior art, the play amount causes a shift between the driving of the motor and the operation of the range switching valve. Therefore, for example, when only the switching position of the range switching valve is detected and the driving of the motor is controlled based on this, the motor may be driven more than necessary. That is, this range switching valve
The motor continues to be driven even though it has reached the position where it starts to run toward the target range position, and an extra load is applied to this motor and its driving power supply (battery).

[0006] The technical problem of the present invention is that a range switching valve is operated by a function of a detent mechanism in a target range position .
When the self-running is started, the drive of the actuator for switching the range switching valve is stopped to perform lean control and reduce the load on the actuator and its power supply.

[0007]

In order to solve the above-mentioned problems, a control device for an automatic transmission according to the present invention is configured as follows. That is, the range switching valve of the automatic transmission is switched by an actuator driven by electrical control, and a predetermined amount of play is provided in a power transmission path between the actuator and the range switching valve. A control device for an automatic transmission in which a switching valve is positioned at a plurality of range positions by a detent mechanism, the range control unit outputting a drive signal for driving the actuator, and a drive amount of the actuator is also detected. An actuator position sensor that outputs the detection signal to the range control unit, and a valve position sensor that detects the operation amount of the range control valve and outputs the detection signal to the range control unit, wherein the range control unit includes: based on the detection signals from both the position sensors of the, the range switching valve in range position of targets Determines that began to self within the I Ri before Kiasobi amount features Itento mechanism, and thereby is configured to output a stop signal for stopping the driving of the actuator.

[0008]

According to this structure, when the range switching valve starts to run by the function of the detent mechanism in the target range position, a signal for stopping the drive of the actuator is output from the range control unit. Is done. Therefore, the actuator is stopped with the minimum necessary driving, and the load on the actuator and its power supply is reduced.

[0009]

Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 2 is a perspective view showing an outline of a range switching valve 30 for switching the traveling range of the automatic transmission and its driving system. The range switching valve 30 is of a spool valve type, and is supplied with a line hydraulic pressure serving as a basic hydraulic pressure for controlling the automatic transmission. By operating the spool of the range switching valve 30 in the axial direction, the discharge port thereof is switched, and the engagement and release of a friction engagement device (not shown) for setting each traveling range is controlled.

A detent lever 36 is fixed on the control shaft 32 shown in FIG. By the rotation of the control shaft 32 around the axis, the rotation of the detent lever 36 causes the range switching valve 3 to rotate.
It is configured to move the zero spool in its axial direction.

The detent lever 36 has a fan shape, and a plurality of uneven portions 36a are formed on the outer periphery thereof. For one of these concave and convex portions 36a,
Roller 3 provided at end of detent spring 38
8a are selectively engaged. These members constitute a detent mechanism 34 for positioning the rotational position of the control shaft 32, that is, a plurality of range positions of the range switching valve 30.

In order to switch the range switching valve 30, a DC motor 50 is used as an actuator driven by electric control. This DC motor 5
The worm 54 formed on the zero drive shaft 52 meshes with a worm wheel 56 disposed coaxially with the control shaft 32. The end of the control shaft 32 is engaged with the boss 58 at the rotation axis of the worm wheel 56 so as to transmit the rotation. Thereby, the drive shaft 52 of the DC motor 50 is
Of the worm 54 and the worm wheel 56
Is transmitted by being decelerated by the meshing with.

FIGS. 3A and 3B show an enlarged view of an engagement portion between the boss 58 of the worm wheel 56 and the end of the control shaft 32. FIG. As is apparent from this drawing, the end of the control shaft 32 is formed in a rectangular cross section, and this portion is inserted into the boss 58. The engaging portion is provided with a predetermined play amount δ with respect to the rotation transmission direction between them. That is, the play amount δ is provided in the power transmission path between the DC motor 50 and the range switching valve 30.

The rotation of the worm wheel 56 accompanying the driving of the DC motor 50 is transmitted to the control shaft 32 with the play amount δ reduced. By the rotation of the control shaft 32, the range switching valve 30 is switched through the detent lever 36 as described above. At this time, in each range position of the range switching valve 30, the engagement of the roller 38a of the detent spring 38 with the concave / convex portion 36a of the detent lever 36 is repeated.

That is, the roller 38a of the detent spring 38 is provided with the concave and convex portions 3 of the detent lever 36.
The operation of overcoming one convex portion 6a and engaging with the adjacent concave portion is repeated. During a period from the time when the roller 38a crosses one convex portion to the time when the roller 38a reaches the concave portion, the control shaft 32 is controlled by the control shaft 32 based on the elastic force of the detent spring 38 regardless of the driving of the DC motor 50. You will be self-propelled within the range.

FIG. 1A is a signal system diagram for electrically controlling the DC motor 50. As shown in FIG. In this drawing, a range selection switch 10 is a position switch that is switched in response to an operation of a select lever by a driver to select a travel range of the automatic transmission, or an operation switch that is directly operated by the driver.

In FIG. 1A, the range control unit 20 (S
The BW control unit uses a microcomputer, a read-only memory (ROM) storing programs necessary for various software processes for switching the running range of the automatic transmission, and a central processing unit (CPU) for executing the programs. ) And a writable memory (RAM) for temporarily storing variables necessary for the program.

The range control unit 20 includes a range signal a output by operating the range selection switch 10 and respective detection signals output from an actuator position sensor 40 and a valve position sensor 42 provided on the automatic transmission side. Signals b and c are both input. Further, a drive signal d corresponding to the range signal a is output from the range control unit 20 to a drive circuit (not shown) of the DC motor 50.

The actuator position sensor 40 is for detecting the driving amount (rotation angle) of the DC motor 50. As shown in FIG. 2, for example, a rotary type sensor (variable resistor) is used for the worm wheel. The rotation angle of 56 is detected as a voltage change. The valve position sensor 42 is for detecting the operation amount of the range switching valve 30. Similarly, a rotary type sensor (variable resistor) is used to detect the rotation angle of the control shaft 32 as a voltage change. Has become.

As described above, the two position sensors 40 and 42 are used.
Since the detection signals b and c output from are analog signals, the respective detection signals b and c are converted into digital signals by an analog / digital (A / D) converter 22 shown in FIG. It is input to the range control unit 20.

As shown in FIG. 4, the actuator position sensor 40 and the valve position sensor 42 have a low (L) voltage value at the range position of the range switching valve 30.
It is set to be lower on the range side and higher on the parking (P) range side. The range switching valve 30 is switched from the L range to the P range (hereinafter referred to as “P direction”), and conversely, is switched from the P range to the L range (hereinafter referred to as “L direction”). 4 and 5, the voltage change of the valve position sensor 42 has a constant pattern as shown in FIG.

However, as for the actuator position sensor 40, when the range switching valve 30 is switched in the P direction, the voltage value changes in a state in which the voltage value is high by the play amount δ as shown in FIG. When the switching valve 30 is switched in the L direction, as shown by C in FIG.
In the state where the voltage value is low.

5 (A) and 5 (B), the range switching valve 30 is set to P by actually driving the DC motor 50.
The voltage changes of the position sensors 40 and 42 when the switching operation is performed in the direction and the L direction are shown. In any direction, when the play amount δ is reduced after the start of the DC motor 50, the drive shaft 52 of the DC motor 50 and the control shaft 32 start rotating in an integrated relationship (one-to-one relationship).

However, as shown in FIG. 5A, when the control shaft 32 is self-propelled by the function of the detent mechanism 34 at each range position when the range switching valve 30 is operating in the P direction, At the location, the voltage value V2 detected by the valve position sensor 42 increases. Further, as shown in FIG.
Is operating in the L direction, if the control shaft 32 runs by itself, the voltage value V2 detected by the valve position sensor 42 becomes low here.

Therefore, when the control shaft 32, that is, the range switching valve 30 is self-propelled, the difference (V2-V1) between the voltage value V2 detected by the valve position sensor 42 and the voltage value V1 detected by the actuator position sensor 40 is obtained. ) Changes greatly. Therefore, when the range switching valve 30 is operating in the P direction, it can be determined that the vehicle is self-running when (V2-V1) exceeds a predetermined voltage value, and when the range switching valve 30 is operating in the L direction. Can be determined to be self-propelled when (V2−V1) is equal to or less than a predetermined voltage value.

FIG. 1B is a flowchart showing the contents of software processing for controlling the drive of the DC motor 50 by the range control unit 20. In step S1 of this drawing, it is determined whether or not the DC motor 50 is being controlled. If the control is being performed, the process proceeds to step S7. In this step S2, it is determined whether or not the range selection switch 10 has changed. If there is a change, the process proceeds to step S3. In this step S3, it is determined whether or not the current range position of the range switching valve 30, that is, the traveling range M of the automatic transmission and the select range S by operating the range selection switch 10 coincide with each other. If not, the process proceeds to step S4.

If it is determined in step S2 that the range selection switch 10 has not changed,
If it is determined in step 3 that the travel range M and the select range S are the same, the process is terminated and the control returns to the normal control.

In step S4, the DC motor 50 is controlled based on the range signal a from the range selection switch 10.
Is determined (P direction or L direction), and
Proceeding to the next steps S5 and S6 for each judgment, the drive signal d is output so as to rotate the DC motor 50 in the P direction or the L direction. Thereafter, the process proceeds to step S7, where it is again determined whether or not the travel range M of the automatic transmission matches the target select range S. If they match, the process proceeds to the next step S8.

In step S8, the self-propelled state of the control shaft 32 is determined by determining a large change in the difference (V2-V1) between the voltage values detected by the position sensors 40 and 42 as described above. . If it is determined that the vehicle is in the self-running state, it means that the range switching valve 30 has started to run in the target range position, and a drive stop signal is output to the drive circuit of the DC motor 50 in the next step S9. To end the processing.

If it is determined in step S7 that the running range M and the select range S do not match,
Alternatively, if it is determined in step S8 that the vehicle is not in the self-running state, the process returns to step S1 to continue the drive control of the DC motor 50.

[0032]

As described above, according to the present invention, the drive of the actuator can be stopped at the time when the range switching valve starts to run in the target range position by itself, thereby enabling the control without waste and the actuator and its control. Power supply load can be reduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing an electric signal system and a control flowchart of a control device in an automatic transmission.

FIG. 2 is a perspective view showing a structure related to a range switching valve for switching a traveling range of the automatic transmission and its actuator.

FIG. 3 is a plan view showing an engagement portion between a control shaft and a worm wheel.

FIG. 4 is a characteristic diagram showing a change in a voltage value detected by an actuator position sensor and a valve position sensor according to a change in a range position of a range switching valve.

FIG. 5 is a characteristic diagram showing voltage changes of an actuator position sensor and a valve position sensor when a range switching valve is switched by driving an actuator.

[Explanation of symbols]

 Reference Signs List 20 range control unit 30 range switching valve 34 detent mechanism 40 actuator position sensor 42 valve position sensor 50 actuator (DC motor) δ play amount

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F16H 59/00-61/12 F16H 61/14-61/24 F16H 63/40-63/48 B60K 20 / 02

Claims (1)

(57) [Claims] A range switching valve of an automatic transmission is switched by an actuator driven by electric control, and a predetermined amount of play is provided in a power transmission path between the actuator and the range switching valve. A control device for an automatic transmission in which a range switching valve is positioned at a plurality of range positions by a detent mechanism, the range control unit outputting a drive signal for driving the actuator, and similarly detecting a drive amount of the actuator. An actuator position sensor that outputs the detection signal to the range control unit, and a valve position sensor that detects the amount of operation of the range control valve and outputs the detection signal to the range control unit. , based on the detection signal from the two position sensors, range switch in the range position targets The valve is in the function of the detent mechanism
Ri determines that began to self within a pre Kiasobi amount, or
One control system for an automatic transmission which is characterized thereby that it is configured to output a stop signal for stopping the driving of the actuator.