JPH05246266A - Speed change control for automatic transmission - Google Patents

Abstract

PURPOSE:To save a lot of trouble to restart an engine with a parking mechanism operated by all means at the time of parking as well as to prevent operations required by a parking range from passing out of mind in an automatic transmission employing the aforesaid hydraulic parking mechanism Which is operated by hydraulic pressure built up when the engine is driven. CONSTITUTION:A range control section 20 electrically selecting the shift range of an automatic transmission AT is equipped with a means detecting the operation of a hydraulic parking mechanism, and with a means detecting the 'ON' and 'OFF' signals of an ignition switch 42. The automatic transmission is also equipped with a means which provides warning to operate a shift lever to a parking position if the operating position of a shift lever is found to have been in a position other than a parking position when it is detected that the ignition switch is turned off, and also holds an ignition coil 34 electrically live until it is detected that the parking mechanism is in operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention employs a hydraulic parking mechanism in which selection of a plurality of shift ranges including a parking range is realized by electric control, and hydraulic pressure generated by driving an engine is used. The present invention relates to a shift control device for an automatic transmission.

[0002]

2. Description of the Related Art In an automatic transmission, selection of each shift range such as drive range, reverse range, parking range, and neutral range for running is performed by switching a range switching valve (manual valve). This range switching valve is generally switched by manual operation, but an automatic transmission having a configuration in which an actuator for driving the switching valve or a solenoid valve for range switching is electrically controlled to select a shift range is also available. Already proposed.

The applicant of the present invention, for example, Japanese Patent Application No. 3-3
It proposes an operating device for an automatic transmission as shown in the specification and the drawings attached to the application No. 04181.
In this device, the contact of the range select switch is switched by operating the shift lever, and the selection of the shift range of the automatic transmission is electrically controlled based on the signal output from the range control unit in response to the contact signal. It has become so.

[0004]

When a hydraulic parking mechanism that operates with hydraulic pressure generated by driving the engine is adopted in the above-mentioned device, if the engine is stopped before operating the shift lever to the parking range position, The parking mechanism will not operate. Therefore, in this case, in order to properly operate the parking mechanism, it is necessary to operate the shift lever to the parking range position after restarting the engine. If the driver does not notice this, the driver may forget to operate the parking range.

A technical problem of the present invention is to provide an automatic transmission employing a hydraulic parking mechanism that operates by hydraulic pressure generated when an engine is driven, when a shift lever is operated to a parking range position when an ignition switch is turned off. If not operated, the operation is urged and the engine stop is held until the parking mechanism is operated, so that the parking mechanism is always operated at the time of parking to save the trouble of restarting the engine and to the parking range. It is to prevent forgetting the operation.

[0006]

In order to solve the above problems, a shift control device for an automatic transmission according to the present invention is constructed as follows. That is, each shift range including the parking range is selected based on the control signal output from the range control unit according to the contact signal of the range select switch that is switched by operating the shift lever, and when the parking range is selected, In the automatic transmission of the type in which the parking mechanism that locks the traveling drive system is operated by the hydraulic pressure generated when the engine is driven, the range control unit includes means for detecting that the parking mechanism is operated, and an on / off signal of an ignition switch. And a warning to operate the shift lever to the parking range position if the operation position of the shift lever is at a position other than the parking range position when the ignition switch is detected to be off, and Par And means for holding the ignition coil energized until the operation of the ring mechanism is detected.

[0007]

According to this structure, when the shift lever is not operated to the parking range position when the engine is stopped by turning off the ignition switch, that is, the parking mechanism locks the traveling drive system of the vehicle. If not in the state, a warning to the driver prompts the driver to operate the shift lever to the parking range position. Until the parking mechanism operates, the ignition coil is kept in the energized state and the stop of the engine is suspended. Therefore, even if the shift lever is not operated to the parking range position at an appropriate time, it is not necessary to restart the engine to achieve the parking range of the automatic transmission.

[0008]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 2 is a perspective view showing a part of the front of the driver's seat of the vehicle. As is apparent from this drawing, a shift lever 10 is arranged on the left side of the steering column portion 14 near the steering wheel 12. This shift lever 1
By operating 0, the range select switch SW for selecting the shift range of the automatic transmission AT, which will be described later, is switched. In FIG. 2, the instrument panel 16 on the front of the driver's seat is provided with a range indicator 25 for displaying the shift range of the automatic transmission AT.

FIG. 3 shows each range position of the shift lever 10 in a plan view. As is apparent from this drawing, an operation line C1 for operating the shift lever 10 at each range position P, R for selecting the parking (P) range and the reverse (R) range of the automatic transmission.
And the operating line C2 for operating the shift lever 10 to the respective range positions N and D for selecting the neutral (N) range and the drive (D) range are offset by a certain amount in parallel with each other.

At the position of the range position D, a range position for selecting a forward traveling range (3, 2, L) other than the D range in the automatic transmission is provided on the operation line C3 orthogonal to the operation line C2. UP and DW are set so as to be distributed to both sides centering on the range position D. The shift lever 10 is moved from the range position D to the range position UP, along the operation line C3.
If you operate the DW and release the operating force,
Shift lever 1 by the function of a detent mechanism (not shown)
0 is returned to the range position D each time.

As described above, the shift lever 10 has the structure shown in FIG.
A shift operation along the operation lines C1 and C2 or an up-down operation along the operation line C3 from the range position D is possible. The contacts of the range select switch SW are switched by these operations of the shift lever 10.

FIG. 1 shows a system diagram of electric control for selecting the shift range of the automatic transmission AT. In this drawing, a range control unit (SBW) 20 is a read-only memory (RO) in which a microcomputer is used and stores programs necessary for shift range switching of the automatic transmission AT and various software processing related thereto.
M), a central processing unit (C
PU), a writable memory (RAM) for temporarily storing variables necessary for a program, and the like.

A microcomputer is also used for the automatic shift control unit (ECT) 22 shown in FIG. 1, and this control unit 22 is known to automatically shift gears on the basis of vehicle speed and engine load (throttle opening). Switching control of the automatic shift solenoid valve 32 in the machine AT is possible. As a result, the automatic transmission AT is automatically switched to each gear.

The automatic transmission AT is equipped with a parking mechanism (not shown) that operates so as to lock the traveling drive system of the vehicle when the shift range is the P range. Further, in this embodiment, a hydraulic parking mechanism that is operated by utilizing the hydraulic pressure generated by driving the engine EG is adopted. When the parking mechanism operates, the parking detection switch 24 shown in FIG. 1 is turned on.

Further, the key cylinder 40 of the ignition key 48 shown in FIG. 1 includes an ignition switch 42 which is turned on / off by operating the key 48, and of course, a key which can lock the extraction of the key 48. An interlock mechanism (not shown) is provided. The key interlock mechanism is operated in a locked state by the key interlock solenoid 44 to prevent the key 48 from being pulled out.

The contact signal of the range select switch SW, which is switched by the operation of the shift lever 10, the detection signal of the parking detection switch 24, and the ON / OFF signal of the ignition switch 42 are input to the range control unit 20. It Further, from the range control unit 20, the automatic shift control unit 22, the power supply circuit of the range switching solenoid valve 30 in the automatic transmission AT, the power supply circuit of the key interlock solenoid 44, the electric circuit of the ignition coil 34, and the range indicator 25. And an electrical signal is output to the voice navigation control unit 26.

The range switching solenoid valve 30
Is switched and controlled based on a signal output from the range control unit 20, whereby the line hydraulic pressure supply path in the automatic transmission AT is switched, and a friction engagement device (not shown) for setting each shift range. Engagement and disengagement is controlled.

When the shift lever 10 is operated to shift along the operation lines C1 and C2 shown in FIG. 3, the contacts of the range select switch SW shown in FIG. 1 according to the range positions P, R, N and D at that time. Are switched, and the electric signal from each contact is input to the range control unit 20.
Further, by operating the shift lever 10 from the range position D to the range position UP or DW side along the operation line C3, a count signal is transmitted from the switch SW to the range control unit 20.

The solenoid valve 30 for range switching is controlled based on a control signal output from the range control unit 20 in response to the contact signal of the range select switch SW to select the shift range of the automatic transmission AT. To be done. The shift range of the automatic transmission AT is from the D range to the 3 range according to the count signal transmitted from the switch SW when the shift lever 10 is operated up or down.
Can be switched to 2 range or L range.

That is, by operating the shift lever 10 to move down from the range position D to the range position DW once, the shift range of the automatic transmission AT is changed to the previous D range.
The range is changed from the range to 3 ranges, and when the switch is turned on twice in succession, the range is changed to 2 and when it is turned on three times in succession, the range is changed to L.
On the contrary, when the shift lever 10 is operated to be moved up to the range position UP, the shift range of the automatic transmission AT is increased by one range L → 2 → 3 → D according to the number of times of operation.

When the shift range of the automatic transmission AT is switched and controlled in this manner, the range indicator 25 shown in FIGS. The display area corresponding to the shift range is lit up. However, when the shift lever 10 is operated up and down in the range position D, the display portion of the D range of the range indicator 25 changes to "D", "3", "2", "L".

Next, the range control unit 2 when parked
The control of 0 will be described with reference to FIG. 4 whose software processing content is shown in a flowchart. In step S1 of FIG. 4, it is determined whether the ignition switch 42 is turned off, that is, the engine EG is stopped. If the result of this determination is YES, the process proceeds to the next step S2, and if the result is NO, the process for the current parking control is ended and the process returns to normal control.

In step S2, it is determined whether the shift lever 10 has been operated to the range position P shown in FIG. However, after the engine EG is stopped, the shift lever 1
Even if 0 is operated to the range position P, the parking mechanism does not operate, and therefore the P range of the automatic transmission AT is not achieved. Therefore, if the determination result in step 2 is YES, the process proceeds to step S3, where it is determined based on the signal from the parking detection switch 24 whether or not the P range is achieved. If the result of this determination is YES, the process proceeds to step S4, where the ignition coil 34 is de-energized to stop the engine EG, and at step S5 the key interlock is released by the control of the key interlock solenoid 44 and this time. Finish the process.

If the determination result in step S2 is NO, that is, if the shift lever 10 is not operated to the range position P, the process proceeds to step S6, in which the key interlock is controlled by the key interlock solenoid 44. Operate in the locked state so that the ignition key 48 cannot be removed. Further, in step S7, the display portion of the range indicator 25 corresponding to the current range position of the shift lever 10 is blinked to warn the driver to operate the shift lever 10 to the range position P. This warning is issued by the range indicator 2
In addition to the blinking of 5, the voice navigation control unit 26
It becomes more reliable by outputting the sound from the speaker 27 of.

After the processing in step S7 is completed,
Further, the process proceeds to step S8 and the ignition coil 34
Is kept energized. As a result, the off operation of the ignition switch 42 is canceled, and the stop of the engine EG is suspended. Therefore, the process proceeds to the next step S9, where the shift range of the automatic transmission AT is shifted to the P range and the process is ended. If the determination result in step S3 is NO, that is, if the P range of the automatic transmission AT is not achieved, the process proceeds to step S8 and the same process as above is continued.

The ROM in the range controller 20
4 and the CPU that executes these steps is mainly used to turn off the ignition switch 42 in the areas S1 and S2 and steps S7 to S9 in FIG. If the shift lever 10 is not operated to the range position P at the time of detection, a warning is issued to operate the shift lever 10 to the range position P, and the ignition coil 34 is operated until the operation of the parking mechanism is detected. It constitutes a means for maintaining the energized state.

[0027]

As described above, according to the present invention, the parking mechanism can be operated without fail during parking,
This saves the trouble of restarting the engine and eliminates forgetting to operate the parking range.

[Brief description of drawings]

FIG. 1 is an electric control diagram showing an outline of a shift control device.

FIG. 2 is a perspective view showing a part in front of a driver's seat of a vehicle.

FIG. 3 is a plan view showing each range position of a shift lever.

FIG. 4 is a flowchart showing the control contents of the range control unit during parking.

[Explanation of symbols]

 10 shift lever 20 range control unit 24 parking detection switch 34 ignition coil 42 ignition switch AT automatic transmission SW select switch

Claims (1)

[Claims] 1. A shift range including a parking range is selected based on a control signal output from a range control unit in response to a contact signal of a range select switch that is switched by operating a shift lever, and a parking range is selected. In an automatic transmission of a type in which a parking mechanism that locks a traveling drive system of a vehicle is actuated by hydraulic pressure generated when an engine is driven, the range control unit includes means for detecting that the parking mechanism has actuated, and an ignition. A means to detect the switch on / off signal and a warning to operate the shift lever to the parking range position if the operation position of the shift lever is at a position other than the parking range position when the ignition switch is detected to be off. And before Shift control device for an automatic transmission, characterized in that it comprises means for holding the ignition coil energized until the operation of the parking mechanism is detected.