JP2002120587A - Shift position detecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To use a potentiometer for accurately detecting the position of a shift lever without being affected by an assembling error, aging deterioration, backlash, etc. SOLUTION: A difference V between an output voltage (P range output value) Vp from the potentiometer for detecting the shift position of a P range and a reference output voltage Vs as preset is calculated (S11), an output voltage Vo from the potentiometer is corrected by the difference V (S13), and the position of the shift lever is detected with reference to a shift position determining map in accordance with the output voltage Vo after correction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a shift position detecting device for detecting a set position of a shift lever based on a voltage value from a potentiometer.

[0002]

2. Description of the Related Art Conventionally, a shift lever provided in an automatic transmission of a vehicle such as an automobile is provided with this shift lever.
A shift position detecting device for confirming a position when set to each range such as P (parking), R (reverse), N (neutral), D (drive), etc. is provided.

[0003] In general, this type of shift position detecting device employs a switch type for switching a contact point in many cases, and a shaft that rotates in response to a shift lever operation by a driver, and a shaft that rotates integrally with the shaft. And a switch that is turned on / off by a rotor that rotates by a rotation angle corresponding to the driver's operation of the shift lever, thereby detecting the position of the shift lever from the output pattern of the ON / OFF signal. I have to.

In this switch type shift position detecting device, at least the number of contacts corresponding to each range is required, and there is a problem that the number of contacts is large and wiring is complicated.

For this reason, recently, for example, Japanese Patent Application Laid-Open No. 7-3
As disclosed in Japanese Patent No. 10823, using a potentiometer, a reference output voltage of a shift position corresponding to each range is stored in advance, and a voltage value output from the potentiometer is compared with a reference output voltage. Techniques for detecting a shift position are known.

According to this technique, the shift position can be detected with one resistor pattern, so that the number of contacts is reduced and the wiring can be simplified.

[0007]

However, in the above-mentioned prior art, since the reference output voltage corresponding to each shift position is an unambiguous fixed value, the mounting error of the potentiometer, the change in the resistance value due to the deterioration over time, and If the backlash increases, the reference position of the shift lever cannot be accurately detected, and it is necessary to readjust the reference position of the shift lever or replace the entire device.

In addition, in the case of outfitting, it is necessary to adjust the reference position for each vehicle, which requires a complicated adjustment operation, which causes an increase in the number of assembling steps.

In view of the above circumstances, the present invention does not require complicated adjustment work, can accurately detect the shift position even if an assembly error, aging deterioration, or backlash occurs. It is an object of the present invention to provide a highly reliable shift position detecting device.

[0010]

To achieve the above object, a shift position detecting device according to the present invention comprises a shift position determining means for determining the position of the shift lever based on a voltage value output from a potentiometer linked to the shift lever. Wherein the shift position determination means compares a reference output voltage value of a specific shift position that is set in advance with the voltage value when the shift lever is set to the specific shift position,
Correction means for correcting the relationship between the voltage value and each shift position based on the voltage comparison value is provided.

In such a configuration, when the shift position determining means detects the set position of the shift lever based on the voltage value output from the potentiometer operating in synchronization with the shift lever, the correcting means uses A preset reference output voltage value of the specific shift position is compared with a voltage value when the shift lever is set to the specific shift position, and based on the voltage comparison value, the voltage value output from the potentiometer and each voltage value are compared. Since the relationship with the shift position is corrected, the position of the shift lever can be accurately detected without being affected by an assembling error, deterioration over time, and play.

In this case, preferably, 1) the correction means corrects the voltage value detected at each shift position based on the comparison value.

2) The correction means learns and corrects a map indicating the relationship between the voltage value and the shift position based on the voltage comparison value.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a perspective view of a main part of the column shift.

Reference numeral 1 in the figure denotes an instrument panel,
Reference numeral 2 denotes a steering wheel. Reference numeral 3 denotes a column cover for covering a steering column (not shown) for fixing the steering wheel 2. A shift lever 3 is disposed on one side of the column cover 3, and a potentiometer 4 is mounted on the shift lever 3. It is installed continuously.

As shown in FIG. 2, the potentiometer 4 has a main body 5 and a movable portion 6 fixed to the vehicle body.

The main body 5 has a variable resistor 7 formed in an arc shape centered on the point O, and a voltage detection pattern 8 formed in a concentric arc shape on the inner periphery of the variable resistor 7. An electrode terminal 7a is formed at one end of the resistor 7, a ground terminal 7b is formed at the other end, and an output terminal 8a is formed at one end of the voltage detection pattern 8, and these terminals 7a, 7b, 8a are formed.
Extend to a connector 5a formed on one side of the main body 5.

An external connector (not shown) is connected to the connector portion 5a, and a constant voltage (+5 V in the present embodiment) is supplied to the electrode terminal 7a from a voltage source (not shown) via the external connector. The ground terminal 7b is connected to the vehicle body ground (GND), and the output terminal 8a is connected to a shift position detection electronic control device (hereinafter, referred to as a "shift position detection ECU") 11, which will be described later.

On the other hand, the movable portion 6 is rotatably supported about the point O with respect to the main body portion 5 and is connected to the shift lever 3 via a link mechanism (not shown). It rotates in synchronization with the operation of the shift lever 3. A brush 9 for electrically connecting the variable resistor 7 and the voltage detection pattern 8 is fixed to the movable portion 6, and the brush 9 turns the variable resistor 7 and the voltage by rotating the movable portion 6. The upper surface slides on the detection pattern 8.

Since a constant voltage (+5 V in this embodiment) is supplied to the variable resistor 7, when the movable part 6 is rotated to move the brush 9, the variable resistor 7 The output voltage value Vo (between the output voltage value Vo and GND) correspondingly divided by the resistance can be detected through the voltage detection pattern 8.

In the present embodiment, the set positions of the shift lever 3 are a parking (P) range, a reverse (R) range, a neutral (N) range, a drive (D) range, and a drive sports mode (Ds) range. Are set in five stages. The rotation angle of the movable portion 6 that rotates synchronously with the shift lever 3 corresponds to each of the ranges P, R, N, D, and Ds in which the shift lever 3 is set.

Therefore, as shown in the schematic diagram of FIG. 3, the angle of the resistance region between both terminals 7a and 7b of the variable resistor 7 is θ,
If the rotation angle from the ground terminal 7b side of the variable resistor 7 to the position of the shift position (for example, P range) to be detected is θo, the output voltage value Vo detected by the voltage detection pattern 8 is Vo = 5 · θo / θ.

The output voltage value Vo is output to the shift position detecting ECU 11 shown in FIG. The shift position detection ECU 11 is provided with a shift position determination unit 11a and a reference output voltage storage unit 11b. The shift position determination section 11a refers to the shift position determination map using the output voltage value Vo from the potentiometer 4 as a parameter, and determines in which range the shift lever 3 is set.

As shown in FIG. 7, in the shift position determination map, P, R,
The respective ranges of N, D, and Ds and the output voltage value Vo obtained from each rotation angle θo at that time are stored.

The reference output voltage storage section 11b stores the output voltage value output from the potentiometer 4 when the shift lever 3 is set to the specified range at the time of engine start.
A design output voltage value (reference output voltage value Vs) that does not consider an assembly error, aging deterioration, play, or the like is stored.
In general, it is a condition that the shift lever 3 when the engine is started is set to the P or N range.
In the present embodiment, the setting is such that the engine start is permitted only when the shift lever 3 is set to the P range. Therefore, the reference output voltage value Vs corresponds to the output voltage value from the potentiometer 4 when the shift lever 3 is set to the P range.

By the way, the relationship between the shift position corresponding to each range of P, R, N, D and Ds and the output voltage value Vo stored in the shift position determination map is as follows.
The actual relationship between each shift position and the output voltage value Vo has a certain deviation width δ due to the effects of assembly errors, deterioration over time, backlash, and the like, as shown by the two-dot chain line in FIG.

In order to correct the deviation width δ, in the present embodiment, the output voltage detected by the potentiometer 4 when the select lever 3 is set to the P range at the time of starting the engine in the shift position determining section 11a. A difference V between the value Vo and the reference output voltage value Vs is obtained, and the output voltage value Vo is corrected according to the difference V.

The shift position determination section 11a includes:
The other ECUs 13 such as an engine control device and a transmission control device are connected to the shift display device 14. The shift display device 14 is provided on an instrument panel (not shown), and is provided with range indicators corresponding to the respective ranges of P, R, N, D, and Ds.

The shift voltage determination unit 11a provides the other ECUs 13 with a predetermined corrected output voltage value Vo.
Is output to the shift display device 14, and a signal for turning on the range indicator corresponding to the detected shift position is output.

The correction processing of the output voltage Vo in the shift position determination section 11a is specifically performed according to the flowcharts of FIGS. FIG. 5 is a flowchart showing a shift position determination main routine, and FIG. 6 is a flowchart showing a shift position determination subroutine.

First, as shown in FIG. 5, when the ignition switch is turned on in step S1, the process proceeds to step S2 to check whether or not the position of the shift lever 3 is set to the P range. In this case, the shift lever 3
Is set to the P range or not?
For example, the determination is made by referring to the shift position determination map using the output voltage Vo of the potentiometer 4 as a parameter.

When the shift lever 3 is in a shift position other than the P range, the process proceeds to step S3.
In order to operate the shift lever 3 to the P range, a warning such as blinking a range indicator light corresponding to the current shift position of the shift display device 14 is issued, and the driver is caused to operate the shift lever 3 to the P range. Prompt and return to step S2.

If the shift lever 3 is set to the P range, the process proceeds to step S4, where the output voltage value Vo of the potentiometer 4 at this time is detected, and at step S5, the output voltage value Vo is set to the P range. The output value Vp is stored in the storage unit.

Next, the process proceeds to step S6, in which the engine start is permitted, and an engine start process is executed in a predetermined manner. Then, after the engine is started, the process proceeds to step S7, in which a shift position determination process at the time of traveling is performed, and step S8
Step S7 is repeatedly performed until the ignition switch is turned off, and the ignition switch is turned off.
When F is reached, the routine ends.

The shift position determination process in step S7 is performed in a traveling shift position determination routine shown in FIG. First, in step S11, the difference V between the P range output value Vp stored in the storage means and the reference output voltage value Vs stored in the reference output voltage storage section 11b is obtained.
(V = Vp−Vs) is calculated.

Then, the process proceeds to a step S12, wherein the output voltage value Vo of the potentiometer 4 is detected, and a step S13 is executed.
Then, the difference V is subtracted from the output voltage value Vo to correct the output voltage value Vo (Vo = Vo-V).

Thereafter, the process proceeds to step S14, in which the position of the shift lever 3 is determined by referring to the shift position determination map shown in FIG. 7 using the corrected output voltage value Vo as a parameter. Through.

As described above, according to the present embodiment, the position of the shift lever 3 at the time of engine start is set to the P range, and when the ignition switch is turned on, the actual P range output value Vp from the potentiometer 4 and the shift A difference V from a designed reference output voltage value Vs when the lever 3 is set to the P range is calculated.
The output voltage value Vo is corrected in accordance with the following equation. Therefore, even if an assembly error, deterioration with time, or backlash occurs, the deviation width δ (see FIG. 7) is corrected after the engine is started. The shift position of the shift lever 3 can be accurately detected.

Therefore, complicated adjustment work after assembly is not required, maintenance and management are easy, and inexpensive and high reliability can be obtained.

The present invention is not limited to the above-described embodiment. For example, the shift position determination map is learned and corrected using the difference V, and thereafter, the learning correction is performed using the output voltage value Vo of the potentiometer 4 as a parameter as it is. The shift position may be detected by referring to the shift position determination map.

Further, the difference V is obtained by comparing steps S2 and S4 in FIG.
, Or between steps S4 to S56, and storing this calculated value in the storage means,
In step S11 in FIG. 6, the difference V is not calculated, and only reading is necessary.

Further, in this embodiment, the shift lever 3
Is permitted only when the shift lever 3 is set to the P range, but the invention is not limited to this. For example, the ignition switch is turned ON only when the shift lever 3 is set to the P range. With this configuration, even if the engine is started in the N and P ranges as in the prior art, the output voltage value V of the P range of the potentiometer
p can be reliably detected.

[0043]

As described above, according to the present invention,
The actual voltage value of the potentiometer when the shift lever is set to each shift position is corrected based on the difference between the reference output voltage of the specific shift position and the actual voltage value when the shift lever is set to the specific shift position. Therefore, no complicated adjustment work is required, the shift position can be accurately detected even when an assembly error, deterioration with time, and backlash occur, and it is possible to obtain low cost and high reliability. .

[Brief description of the drawings]

FIG. 1 is a perspective view of a main part of a column shift.

FIG. 2 is a configuration diagram of a potentiometer.

FIG. 3 is a schematic diagram of a potentiometer.

FIG. 4 is a block diagram of a shift position detecting device.

FIG. 5 is a flowchart showing a shift position determination main routine.

FIG. 6 is a flowchart showing a shift position determination subroutine.

FIG. 7 is an explanatory diagram showing a shift position determination map.

[Explanation of symbols]

 Reference Signs List 3 shift lever 4 potentiometer 11 shift position detection ECU 11a shift position determination means Vo output voltage value Vs reference output voltage

Claims (3)

[Claims] 1. A shift position determining means for determining a position of the shift lever based on a voltage value output from a potentiometer linked to the shift lever, wherein the shift position determining means has a predetermined specific shift position. Correction means for comparing a reference output voltage value with the voltage value when the shift lever is set to the specific shift position and correcting the relationship between the voltage value and each shift position based on the voltage comparison value is provided. A shift position detecting device, comprising: 2. The shift position detecting device according to claim 1, wherein said correction means corrects said voltage value detected at each shift position based on said voltage comparison value. 3. The shift position detecting device according to claim 1, wherein the correction means learns and corrects a map indicating a relationship between the voltage value and the shift position based on the voltage comparison value.