JPH0562270B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a shift control device for a vehicle automatic transmission. (Prior Art) In recent years, the wave of electronicization of vehicles, especially automobiles, has been remarkable, and with this, it has become possible to display various vehicle statuses on the display panel in the driver's seat.
It is used to call the driver's attention or for their convenience. For example, the same applies to an automatic transmission control system as shown in Fig. 2, and the transmission operating device
Control device CT depending on the position of the ATO operating lever CL
controls the engine ENG and transmission ATM, automatically shifting the gears, and displays the operating lever on the display panel DP.
Show CL position. That is, the control device CT is composed of a microcomputer, and the processor 11 performs arithmetic operations according to the control program stored in the program memory 12. The operating lever CL is linked to the position switch PSW, and the data address Input/output port 15 via bus 16
The operation lever position selection signal ("R", "N",
"D", "5", "4", "3", "2", "1"), the transmission ATM is selected via the bus 16, and the transmission
The ATM is caused to perform a predetermined automatic speed change operation, and the control lever position selection signal is sent to the display panel DP via the bus 16 and the input/output port 14 to display the control lever position. Further, when the operating lever CL selects the "D" (drive) position and the operating lever position selection signal "D" is turned on, the processor 11 generates an opening signal from the signal generating circuit 20 according to the amount of depression of the accelerator ACC. degree signal ACS & engine
Reads the rotation speed signal TGS from the rotation speed detector TG21 that detects the rotation speed of the ENG via the bus 16,
The optimum gear position (from 1st gear to
The transmission ATM is selectively driven via the bus 16 to perform an automatic gear shift operation, and the position selection signal "D" of the operation lever
6. Display the feed operation lever position "D" on the display panel DP via the input/output port 14. Note that each read signal and calculation result is stored in the data memory 13. In this way, the control device CT is a position switch whose contacts are turned on depending on the position of the operating lever CL.
The on/off signals of each contact of the PSW are read in parallel, and the display lamps of the display panel DP are driven in parallel to display the position of the operating lever. Similarly, the same applies to warning displays from each sensor for oil pressure, water temperature, fuel consumption, exhaust gas, and window washer fluid, as well as warning displays for door opening/closing. By the way, in such an automatic transmission control system,
The transmission is controlled to change speed according to the operation lever selection signal, but if the operation lever position becomes unstable or there is an abnormality in the operation lever position switch, all or some of these position switches may be activated at the same time. It may turn on or off. In the transmission control in such a case, in order to ensure the safety of vehicle running, the control device CT controls the transmission ATM as follows.
control. (a) Position switch PSW contacts R, N, D,
If only one of the switches 5, 4, 3, 2, and 1 is on, normal speed change control corresponding to that switch is performed. (b) All position switches R, N, D, 5,
If 4, 3, 2, and 1 are turned off, the gear shift will be controlled to neutral when the vehicle is stopped, and the last operating lever will be controlled when the vehicle is moving.
Maintain the shift mode corresponding to CL. (c) When two or more position switches are turned on, the shift mode corresponding to the previous operation lever CL is maintained. In addition, it is possible to judge whether or not the operation lever position is normal based on the number of on/off times of the position switch.
For example, this is done as follows. That is, the control device CT determines that the position switch is on as "1" and that the position switch is off as "0", and outputs "1" every sampling period.
and the number of "0"s, and based on these numbers, it is determined whether or not the operating lever position detection operation is normal. Although not shown in the figure,
The currently operating gear position sent from the transmission is stored in one of the buffers of the microcomputer, and the stored contents are refreshed every sampling period. (Problem to be solved by the invention) However, two position switches R,
If D is turned on and the previous gear shift position is "R", there will be a problem where you will go backwards against your will even though you are trying to move forward by changing from "R" to "D", causing an emergency situation. is dangerous. Similarly, when the vehicle is running and all position switches R,
When N, D, 5, 4, 3, 2, and 1 are turned off, the same danger as described above occurs when the previous displacement position is "R". Furthermore, if the gear shift position is "R" and the vehicle is reversing, an accident may occur in which the "R" switch malfunctions and becomes open, and at the same time, for example, a piece of metal gets into the "D" switch. If this is turned on, the same danger as above will occur. The present invention has been made to solve these conventional problems, and aims to prevent the risk of the vehicle moving backwards unexpectedly due to malfunction or failure of the position switch. (Means for Solving the Problems) The present invention provides an automatic transmission that performs automatic speed change control according to the outputs of a plurality of position switches that are selectively operated by operating levers. There are two reverse position switches that form a
The vehicle is equipped with a control device that places the transmission in either the neutral gear or the forward gear unless two reverse position switches are turned on at the same time. (Function) As described above, in this invention, among the plurality of position switches selectively operated by the operating lever, the conventional "R" switch is electrically connected in parallel, and the operating lever is " There is also another position switch that is turned on when in the "R" position. When the operating lever is in the reverse position, this operating lever turns on two switches at the same time.
Only when the theoretical product of each switch is obtained can it be confirmed that the operating lever is normally in the retracted position, and furthermore, can it be confirmed that the position switch and its circuit are also normal. Then, only when the two reverse position switches are turned on at the same time, the vehicle reverses the gear change mode, regardless of the state of the other forward position switches. When one of the two reverse position switches and the other forward position switch are turned on at the same time, select the shift mode using that forward position switch,
All position switches are turned off during forward movement, or two or more position switches for forward movement are turned off.
When more than one shift mode is turned on, the immediately previous shift mode is maintained, or if the immediately previous shift mode was a reverse shift mode, the neutral shift mode is set. In this way, the vehicle is prevented from moving backward against the driver's will despite an unexpected failure of each position switch. (Embodiment) Fig. 1 is an electrical circuit diagram of a position switch that is switched by an I-type operation lever of the present invention. The position switch has Rs connected in parallel. Therefore, there are a total of 9 position switches from Rs to 1 forward stage.
If all switches Rs are normal, these switches R and Rs are operated at the same time by operating the operating lever, and the other switches N, D, 5, 4, 3, Only one of 2 and 1 is selectively operated. Therefore, when the two position switches R and Rs are closed at the same time, the vehicle reverse gear shift mode is established for the first time, thereby improving the reliability and certainty of the reverse gear shift mode. In addition, by adding a position switch Rs, the control device CT calculates the reverse shift mode and controls the transmission ATM, and also controls the other position switches N, D, 5, 4, 3, 2, In the event of a malfunction or operational error in conjunction with 1.
The backup control operation as a safety system is executed as follows. Next, this backup control operation will be described. (A) In Fig. 1, the position switches Rs, R, N, D,
When 5, 4, 3, 2, 1 are off. (i) When the vehicle speed is 0 (stopped), the control device CT sets the transmission ATM to neutral “N”.
Control the speed change mode. (ii) When the vehicle speed is not 0 (while driving), the shift mode immediately before operating the control lever is maintained, and the shift mode immediately before that is "R" or "Rs".
When this is the case, control is performed to the neutral "N" speed change mode. (B) When two position switches are turned on at the same time. (i) When the two position switches that are turned on are not R or Rs, the immediately previous shift mode is maintained. (ii) Position switch R, Rs and other position switches N, D, 5, 4,
When one of the other position switches 3, 2, and 1 is on, priority is given to the shift mode using the other position switch. (C) When three or more position switches are turned on at the same time. (i) When both positions R and Rs are turned on and the other position switches are turned on, it is assumed that the operation lever is correctly instructing the vehicle to go backwards, and the vehicle enters the reverse shift mode. (ii) Position switches N, D, 5, 4, 3, 2, 1 other than position switches R, R, s
When three or more of them are turned on at the same time, the immediately previous shift mode is maintained. Table 1 is a control operation table for setting an appropriate speed change mode in accordance with each of the above cases, and the speed change operation is set on the condition that there is no failure of two or more position switches at the same time. That is, in the present invention, when only "R" and "Rs" of the position switch are both on,
Make the vehicle perform normal reverse operation, and the previous shift mode was "reverse", and one or both of the position switches "R" and "Rs" and any position switch other than reverse When turned on, the shift position is considered to be reverse and the vehicle continues to move backward, and the control device CT remembers that there is a failure in the position switch and enters various backup operations. Find out if the position switch is malfunctioning. Note that the detection of other position switch failures is the same as in the conventional method.

[Table] This is a problem unique to automatic transmissions caused by the failure of the position switch that operates in response to the operation of the control lever. Regardless, the danger of the vehicle moving backwards against one's will can be prevented. Incidentally, the problem of moving forward against one's will when attempting to go backwards can also be solved using the same idea as above. (Effects of the Invention) As explained above, according to the present invention, it is possible to reverse the vehicle only when two dedicated position switches are turned on at the same time. When the above position switches are turned on at the same time, it is possible to prevent the vehicle from traveling in a direction unexpected by the driver, thereby ensuring driving safety. Further, the same effect can be obtained even when the operating position of the operating lever becomes unstable and a situation similar to that described above occurs in the position switch.

[Brief explanation of the drawing]

FIG. 1 is an electric circuit diagram of a position switch in an automatic transmission according to the present invention, and FIG. 2 is a control system diagram of the automatic transmission for a vehicle. Rs, R, N, D, 5, 4, 3, 2, 1...Position switch, CL...Operation lever, ATM...
Transmission, CT...control device, ENG...engine.

Claims (1)

[Claims] 1. In an automatic transmission device that performs automatic speed change control according to the outputs of a plurality of position switches selectively operated by operating levers, two reverse position switches are provided which, when turned on at the same time, form a reverse speed change mode for the vehicle. , except in the case where the two reverse position switches are turned on at the same time when the plurality of position switches mentioned above are out of order.
An automatic transmission device characterized by being provided with a control device that enables shifting to neutral or forward gears.