JP2004316697A - Selection assist device for automatic transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a selection assist device for an automatic transmission capable of preventing the wrong operation when an engine is rotated at high speed and an influence by the wrong operation of a select lever is large without adding a mechanical structure for preventing the wrong operation to the select lever. <P>SOLUTION: This selection assist device for an automatic transmission is provided with a torque sensor 12 for detecting the input torque to the select lever 2 of the automatic transmission 8, a potentiometer 13 for detecting stroke angle of the select lever 2, an electric motor 7 for outputting the assist torque for assisting the operating force of a driver, a control unit 14 for controlling the assist torque on the basis of the input torque and the stroke angle, and an engine speed sensor 25. When input of the torque to the select lever 2 in a N-range position is detected and in the case where the engine speed Ne is larger than the first set engine speed Ne<SB>1</SB>, the assist torque is output in a direction opposite to the input torque to lighten a warning lamp 24. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a select assist device for an automatic transmission that assists a driver in operating a select lever, and more particularly to a technique for preventing range switching due to erroneous operation of a select lever during traveling.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in a vehicle equipped with a manual transmission, a shift assist device that controls an electric motor for shift assist according to a shift stroke position of a shift lever and a shift operation force is known (for example, Patent Document 1).
[0003]
By the way, when this conventional technology is applied to a select lever of an automatic transmission, and assist is performed in accordance with the stroke position and the operating force of the select lever, the assist force also acts on a driver's erroneous operation. Switching may occur. Then, the influence of this erroneous operation (for example, a shift shock or the like) increases as the engine speed increases.
[0004]
Therefore, as a technique for preventing an erroneous operation of the select lever, there is known a structure in which a plunger of a solenoid is driven so that a metal fitting provided at the tip of the plunger advances and retreats on a track of the select lever (for example, see Patent Document 2). ).
[0005]
That is, the solenoid is controlled by the vehicle speed, and when the vehicle speed is higher than a predetermined constant vehicle speed, the solenoid is driven to move the metal fittings onto the path of the select lever, thereby restricting the movement of the select lever. Even when the button is pressed, erroneous operation of the select lever can be prevented.
[0006]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 2002-13634 [Patent Document 2]
Japanese Utility Model Laid-Open Publication No. 7-29355
[Problems to be solved by the invention]
However, in the above-mentioned conventional technology, a solenoid, a control circuit, and the like for controlling the movement of the select lever are required, so that there is a problem that the device becomes complicated and the cost is increased.
[0008]
The present invention has been made in view of the above-described problem, and has as its object the purpose of the present invention when the engine is operated at a high engine speed where the influence of the erroneous operation of the select lever is large without adding a mechanical erroneous operation prevention structure to the select lever. An object of the present invention is to provide a select assist device for an automatic transmission that can prevent an erroneous operation.
[0009]
[Means for Solving the Problems]
To achieve the above object, the automatic transmission select assist device according to the first aspect of the present invention includes an input torque detection unit that detects an input torque to a select lever connected to a range switching device of the automatic transmission. Operating position detecting means for detecting an operating position of the select lever, an assist actuator for outputting an assist torque for assisting a driver's operating force to the select lever, an input torque to the select lever and an operating position of the select lever. And an assist torque control means for controlling an assist torque based on the engine torque, wherein an engine speed detection means for detecting an engine speed is provided. At high speeds, the driver's operating force is higher than at low engine speeds. Characterized in that a erroneous operation prevention control unit that controls the assist torque so that.
[0010]
According to a second aspect of the present invention, in the select assist device for an automatic transmission according to the first aspect, the erroneous operation prevention control unit stops outputting assist torque.
[0011]
According to a third aspect of the present invention, in the select assist device for an automatic transmission according to the first or second aspect, the erroneous operation prevention control unit is configured to control the engine speed when the engine speed is equal to or higher than a preset speed. The assist torque is controlled so that the driver's operation force is increased.
The “set rotation speed” refers to an engine rotation speed at which a failure may occur when the range is switched at or above this rotation speed.
[0012]
According to a fourth aspect of the present invention, in the select assist device for an automatic transmission according to any one of the first to third aspects, the erroneous operation prevention control unit is configured to input an input to a select lever located at an N range position. When the torque is detected, the assist torque is controlled so that the driver's operation force is increased.
[0013]
【The invention's effect】
According to the first aspect of the present invention, the assist torque control means controls the assist torque based on the input torque to the select lever and the operation position of the select lever in a normal select operation, and the driver operates the select lever. In order to assist the force, the driver can perform the select operation with a small operation force.
[0014]
On the other hand, the assist torque control means includes an erroneous operation prevention control unit that controls the assist torque so that the driver's operation force is higher when the engine is running at a high speed than when the engine is running at a low speed.
[0015]
Therefore, when the engine is running at a high speed, the required operating force of the select lever is increased, and the select lever is less likely to be erroneously operated. Without this, it is possible to prevent an erroneous operation during high engine rotation, which is greatly affected by an erroneous operation of the select lever.
[0016]
According to the second aspect of the present invention, the erroneous operation prevention control unit stops the output of the assist torque when the engine is running at a high speed, so that the operation of the select lever becomes more difficult and the erroneous operation of the select lever can be more reliably prevented.
[0017]
In the invention according to claim 3, the erroneous operation prevention control unit controls the assist torque so that the driver's operation force is increased when the engine speed is equal to or higher than the set speed at which there is a risk of failure. The occurrence of a failure due to an erroneous operation of the select lever can be prevented.
[0018]
According to the fourth aspect of the invention, the erroneous operation prevention control unit prevents the erroneous operation by increasing the operation force of the driver when the input torque to the select lever in the N range position is detected. Therefore, for example, when the vehicle is stopped in the N range at the intersection, when the driver is depressing the accelerator pedal, and the D range or the R range is selected due to an erroneous operation of the select lever, a sudden start and a large shift shock may occur. It can be prevented from occurring.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described below with reference to the drawings.
First, the configuration will be described.
FIG. 1 is a side view showing a configuration of an automatic transmission to which a select assist device for an automatic transmission according to the present invention is applied, and FIG. 2 is a rear view of the automatic transmission.
[0020]
The control unit 1 has a select lever 2 operated by the driver, and is installed, for example, above the center cluster 3 beside the driver's seat. The select lever 2 is set to be operated in the front-rear direction of the vehicle about the fulcrum shaft 4 at the lower end. The length of the select lever 2 is set to about 100 mm, and is designed to be about 250 mm shorter than a conventional general select lever.
[0021]
An upper end of a control lever 5 that rotates vertically with the fulcrum shaft 4 is fixed to the fulcrum shaft 4 of the select lever 2. Further, a sector gear 6 is fixed to the fulcrum shaft 4, and an electric motor (assist actuator) 7 for assisting a driver's operation force is connected to the sector gear 6.
[0022]
The lower end of the control lever 5 is connected via a rod-shaped linkage 11 to the upper end of a control arm 10 of a detent mechanism 9 (see FIG. 3) provided in a front automatic transmission 8. The detent mechanism 9 will be described later.
[0023]
The fulcrum shaft 4 of the select lever 2 includes a torque sensor (input torque detecting means) 12 for detecting an input torque to the fulcrum shaft 4 and a potentiometer (operation position detecting means) 13 for detecting a stroke angle of the select lever 2. Are linked.
[0024]
The torque sensor 12 includes a pair of rotating parts 12a provided on the fulcrum shaft 4 and a detecting part 12b for detecting a torsional torque therebetween. Since the torque sensor 12 is provided on the fulcrum shaft 4 of the select lever 2, it is possible to detect the driver's operation force actually input to the select lever 2. The output voltage of the torque sensor 12 is output to a control unit (assist torque control means) 14 as an input torque signal.
[0025]
Further, the potentiometer 13 detects a stroke angle when the select lever 2 is operated, assuming that the time when the select lever 2 is located at the end of the P range is 0 degree. The output voltage of the potentiometer 13 is output to the control unit 14 as a stroke angle signal.
[0026]
An input torque signal, a stroke angle signal, and an engine speed signal from an engine speed sensor (engine speed detecting means) 25 via the ECU 22 are input to the control unit 14. Then, the control unit 14 sets a target which is a target value of the assist torque output by the electric motor 7 based on the detected stroke angle of the select lever 2 and a preset target assist torque map (see FIG. 4). Calculate the assist torque. Then, the target assist torque is corrected according to the actual input torque, and based on the corrected target assist torque, the output duty ratio of the assist torque output from the electric motor 7 is controlled by a PWM (pulse width modulation) method.
[0027]
If the control unit 14 determines that the select lever 2 is erroneously operated based on the engine speed signal and the input torque, the control unit 14 performs control to prevent range switching due to erroneous operation, and outputs a warning output signal. Then, a warning lamp (warning means) 24 provided on an instrument panel (not shown) is turned on.
[0028]
Next, the structure of the detent mechanism 9 will be described.
FIG. 3 is a perspective view showing the structure of the detent mechanism 9 of the automatic transmission.
A rotating shaft 15 is provided at the lower end of the control arm 10, and a detent plate 16 is supported on the rotating shaft 15. At the upper end of the detent plate 16, valleys 16b corresponding to four ranges (P, R, N, D) are formed between the cam ridges 16a. Then, a detent pin 18 formed at the tip of the spring plate 17 is engaged with the valley portion 16b to maintain the selected range position.
[0029]
That is, by operating the select lever 2 back and forth, the operating force is transmitted to the detent plate 16 via the linkage 11, and the detent plate 16 moves back and forth, so that the detent pin 18 rides over the cam mountain 16a. The valley portion 16b corresponding to the next range is engaged, and the engaged range position is held by the elasticity of the spring plate 17.
[0030]
One end of a parking pole 19 is rotatably connected to the detent plate 16. When the select lever 2 is moved to the P range, the parking pawl 19 prevents rotation of the parking gear 21 via the cam-shaped plate 20 and locks driving wheels (not shown). Thus, when the vehicle is parked in the P range on a slope road, a heavy load is applied so as to lock the drive wheels according to the slope, and acts as a force to bite the parking pole 19.
[0031]
Next, the operation will be described.
[Target assist torque map]
FIG. 4 is a target assist torque map in the P → R range direction. In this target assist torque map, a target assist torque Tmot according to the stroke angle of the select lever 2 is set. The target assist torque Tmot is obtained by subtracting the shaft torque due to the ideal operating force Ft from the shaft torque due to the mechanical load force Fmis. That is, by controlling the assist torque of the electric motor 7 using the target assist torque Tmot as a target value, a shaft torque based on the ideal operating force Ft of the driver, which becomes a favorable operating force at the time of selection, can be obtained.
[0032]
The mechanical load force Fmis is obtained by combining the load force generated by the detent mechanism 9 of the automatic transmission 8 described above with the friction force of the linkage 11, the inertia of the electric motor 7, and the like. In order to perform range switching in a state where there is no operation, an operating force equal to or greater than the shaft torque due to the mechanical load force Fmis is required.
[0033]
When selecting in the D → N range direction, the shaft torque due to the mechanical load force Fmis has a characteristic different from the mechanical load force in the P → R range direction described above. Is also set separately. Therefore, in the assist control of the select lever 2, it is necessary to detect the operation direction of the select lever 2 and to control the assist torque using the target assist torque map corresponding to the operation direction.
[0034]
As a method of detecting the operation direction of the select lever 2 (corresponding to the operation direction detection means), a determination based on the positive / negative output state of the torque sensor 12, a determination based on an increase / decrease difference between the latest acquired value of the potentiometer 13 and the previous acquired value, or , The magnitude of the potentiometer 13 with respect to the median value of each range stop position on the target assist torque map can be determined.
[0035]
A plurality of the target assist torque maps are set in advance according to the operation speed of the select lever 2. The operation speed of the select lever 2 can be estimated from the stroke angle change rate and the like.
[0036]
[Select lever misoperation prevention control processing]
FIG. 5 is a flowchart showing the flow of the select lever erroneous operation prevention control process executed by the control unit 14.
[0037]
In step S101, the engine speed Ne is read from the engine speed signal of the engine speed sensor 25.
[0038]
In step S102, the input torque is read from the input torque signal of the torque sensor 12.
[0039]
In step S103, it is determined whether the input torque is greater than zero. If the input torque is greater than zero, the process proceeds to step S104, and if the input torque is zero, the control ends.
[0040]
In step S104, it is determined from the stroke angle signal of the potentiometer 13 whether or not the select lever 2 is at the N range position. When the select lever 2 is at the N range position, the process proceeds to step S111 in FIG. 6, and otherwise, the process proceeds to step S105.
[0041]
In step S105, the normal operation force assist control described later is executed, and the control ends.
[0042]
FIG. 6 is a flowchart showing the flow of the select lever erroneous operation prevention control process in the D or R range.
[0043]
In step S111, it is determined whether or larger than a first set engine speed Ne ₁ the engine speed Ne is set in advance. Proceeds to the engine rotational speed Ne is first set engine speed Ne ₁ step S117 in greater than, when the engine rotational speed Ne is first set below the engine rotational speed Ne ₁ goes to step S112. Note that the first set engine speed Ne _1, when the select lever 2 is erroneous when the engine rotational speed refers to engine speed with a risk of failure.
[0044]
In step S112, it is determined whether or not the engine speed Ne is higher than a second set engine speed Ne ₂ (0 <Ne ₂ <Ne ₁ ). Proceeds to the engine speed Ne second set engine speed Ne ₂ steps S116 to greater than, when the engine speed Ne is the second set engine speed Ne ₂ or less, the process proceeds to step S113. Note that the second set engine speed Ne _2, when the select lever 2 is erroneous when the engine rotational speed, but you it is not a failure, there is a possibility that sudden acceleration and large shift shock is generated engine Refers to the number of rotations.
[0045]
In step S113, it is determined whether or not the engine speed Ne is higher than a third set engine speed Ne ₃ (0 <Ne ₃ <Ne ₂ ). Proceeds to the engine speed Ne third set engine speed Ne ₃ step S115 in greater than, when the engine speed Ne is the second set engine speed Ne ₂ or less, the process proceeds to step S114. Note that the third set engine speed Ne ₃ means that when the select lever 2 is erroneously operated at this engine speed, there is a low possibility that a sudden start or a large shift shock will occur, but this has an undesirable effect on vehicle behavior. Means the engine speed that may give
[0046]
In step S114, the normal operation force assist control described later is executed, and the control ends.
[0047]
In step S115, the electric motor 7 is controlled so that the assist torque is weakened as compared with the later-described normal control (see FIG. 7), and the present control is ended (corresponding to an erroneous operation prevention control unit). At this time, a warning output signal may be output to turn on the warning lamp 24.
[0048]
In step S116, the output of the electric motor 7 is stopped, a warning output signal is output to turn on the warning lamp 24, and the control is terminated (corresponding to an erroneous operation prevention control unit).
[0049]
In step S117, the electric motor 7 is controlled so that the assist torque is generated in the direction opposite to the moving direction of the select lever 2, a warning output signal is output to turn on the warning lamp 24, and the control is ended (error operation prevention control). Part).
[0050]
[Select lever assist control processing]
FIG. 7 is a flowchart showing the flow of the select lever assist control process executed in step S105 of FIG. 5 and step S114 of FIG.
[0051]
In step S201, the stroke angle of the select lever 2 is read from the stroke angle signal of the potentiometer 13.
[0052]
In step S202, the input torque is read from the input torque signal of the torque sensor 12.
[0053]
In step S203, the operation direction of the select lever 2 is calculated from the positive / negative output state of the input torque signal of the torque sensor 12.
[0054]
In step S204, the operation speed of the select lever 2 is calculated from the stroke angle and the change rate of the previously read stroke angle.
[0055]
In step S205, a target assist torque map corresponding to the operation direction and operation speed of the select lever 2 is read.
[0056]
In step S206, the target assist torque is set based on the read target assist torque map and the stroke angle.
[0057]
In step S207, the actual input torque is compared with the target assist torque, and when the difference is equal to or more than a predetermined value, the target assist torque is corrected.
[0058]
In step S208, the electric motor 7 is driven such that the corrected target assist torque is obtained, and the present control ends.
[0059]
[Control action to prevent erroneous operation of the select lever]
(Prevention of erroneous operation from N range to D range)
When the driver erroneous operation of the select lever 2 from the N range position to the D range direction, when the engine speed Ne is greater than the first set engine speed Ne _1, in the flowchart of FIG. 5, step S101 → step S102 The process proceeds from step S103 to step S104, and then proceeds from step S111 to step S117 in the flowchart of FIG.
[0060]
That is, it is determined in step S103 that the input torque is equal to or greater than zero, and in step S104, it is determined that the select lever 2 is at the N range position. Subsequently, at step S111 in FIG. 6 is determined that the engine rotational speed Ne is greater than a first set engine speed Ne _1, in step S117, D → N range direction, i.e., in a direction that prevents the movement of the select lever 2 The assist torque of the electric motor 7 is output. At this time, the warning lamp 24 lights up, and the driver is warned of an erroneous operation.
[0061]
Also, larger than the engine rotational speed Ne is the second set engine speed Ne _2, when it is first set engine speed Ne ₁ below, in the flowchart of FIG. 6, to the step S 111 → step S112 → step S116 It is a flow to go.
[0062]
That is, in step S111 the engine rotational speed Ne is determined to be first set below the engine rotational speed Ne _1, the engine speed Ne in step S112 is determined to be larger than the second set engine speed Ne _2, step S116 As a result, the output of the assist torque by the electric motor 7 is stopped, and the warning lamp 24 is turned on.
[0063]
Furthermore, greater than the engine speed Ne third set engine rotational speed Ne _2, when it is the second set engine speed Ne ₂ or less, in the flowchart of FIG. 6, step S 111 → step S112 → step S113 → step The flow proceeds to S115.
[0064]
That is, it is determined that the engine speed Ne in step S111 is first set below the engine rotational speed Ne _1, in step S112 it is determined that the engine rotational speed Ne is the second set engine speed Ne ₂ below, step S113 by it is determined that the engine rotational speed Ne is greater than the third predetermined engine speed Ne _3, the output of the assist torque by the electric motor 7 is stopped in step S115, the warning lamp 24 is turned on.
[0065]
Next, effects will be described.
With the automatic transmission select assist device according to the present embodiment, the following effects can be obtained.
[0066]
(1) parked in a state of stepping on the accelerator pedal in the driver N range, when the select lever 2 is erroneous, when the engine speed Ne is greater than the first set engine speed Ne ₁ the select lever 2 By outputting the assist torque of the electric motor 7 in a direction that hinders the movement of the vehicle, range switching by the driver's operation force is disabled, and erroneous operation can be reliably prevented, and sudden start of the vehicle and a large shift shock can be avoided. .
[0067]
(2) parked in a state of depressing the accelerator pedal driver in N range, when the select lever 2 is erroneous, greater than the engine speed Ne is the second set engine speed Ne _2, first set engine speed In the case of Ne ₁ or less, the output of the assist torque by the electric motor 7 is stopped, so that the driver can be alerted to deceleration or the like while suppressing the power consumption of the electric motor 7, and the sudden change in the vehicle behavior It is possible to prevent erroneous operations involving At this time, the select lever 2 becomes heavy due to the stoppage of the output of the assist torque. However, if the driver must change the range in order to avoid danger, the range can be changed.
[0068]
(3) the vehicle is stopped in a state of stepping on the accelerator pedal the driver in the N range, when the erroneous operation of the select lever 2, greater than the engine speed Ne third set engine speed Ne _3, the second set engine speed If Ne is ₂ or less, the output of the assist torque by the electric motor 7 is made weaker than usual, so that the select operation force is made heavier than usual and the driver can be alerted to deceleration, etc. It is possible to prevent erroneous operation of the select lever 2 that may have an undesirable effect.
[0069]
(4) When the select lever 2 is erroneous, when the engine speed Ne is greater than the third predetermined engine speed Ne _3, for a warning to the driver by lighting a warning lamp 24, the attention of the driver It is possible to reliably prevent range switching due to erroneous operation.
[0070]
(Other embodiments)
Although the embodiments of the present invention have been described above, the specific configuration of the present invention is not limited to the embodiments, and even if there is a design change or the like within a range not departing from the gist of the invention, Included in the present invention.
[0071]
For example, as the warning means, in addition to turning on the warning lamp 24, a warning may be displayed to the driver for an erroneous operation, a character requesting deceleration, or a warning sound or sound may be issued.
[Brief description of the drawings]
FIG. 1 is a side view showing a configuration of an automatic transmission to which a select assist device for an automatic transmission according to the present invention is applied.
FIG. 2 is a rear view showing a configuration of an automatic transmission to which the select assist device for an automatic transmission according to the present invention is applied.
FIG. 3 is a perspective view showing a structure of a detent mechanism of the automatic transmission.
FIG. 4 is a target assist torque map in a P → R range direction.
FIG. 5 is a flowchart illustrating a flow of a select lever erroneous operation prevention control process executed by the control unit.
FIG. 6 is a flowchart showing a flow of a select lever erroneous operation prevention control process in an N range executed by the control unit.
FIG. 7 is a flowchart illustrating a flow of a select lever assist control process executed by the control unit.
[Explanation of symbols]
Reference Signs List 1 control unit 2 select lever 3 center cluster 4 fulcrum shaft 5 control lever 6 sector gear 7 electric motor 8 automatic transmission 9 detent mechanism 10 control arm 11 linkage 12 torque sensor 12a rotating unit 12b detecting unit 13 potentiometer 14 control unit 15 rotating shaft 16 Detent plate 16a Cam peak 16b Valley 17 Spring plate 18 Detent pin 19 Parking pole 20 Cam-shaped plate 21 Parking gear 22 ECU
24 Warning lamp 25 Engine speed sensor

Claims (4)

Input torque detecting means for detecting an input torque to a select lever connected to a range switching device of the automatic transmission,
Operating position detecting means for detecting an operating position of the select lever;
An assist actuator that outputs an assist torque to assist a driver's operation force to a select lever;
Assist torque control means for controlling an assist torque based on an input torque to the select lever and an operation position of the select lever,
A select assist device for an automatic transmission having
An engine speed detecting means for detecting the engine speed is provided,
The assist torque control means is provided with an erroneous operation prevention control unit that controls the assist torque so that the driver's operation force is increased when the engine is running at a high speed as compared to when the engine is running at a low speed. Select assist device for automatic transmission. The select assist device for an automatic transmission according to claim 1,
The select assist device for an automatic transmission, wherein the erroneous operation prevention control unit stops output of assist torque. The select assist device for an automatic transmission according to claim 1 or 2,
The select assist device for an automatic transmission, wherein the erroneous operation prevention control unit controls the assist torque so that the driver's operation force is increased when the engine speed is equal to or higher than a preset speed. The select assist device for an automatic transmission according to any one of claims 1 to 3,
The erroneous operation prevention control unit controls the assist torque such that when the input torque to the select lever in the N range position is detected, the assist torque is increased so that the driver's operation force is increased. apparatus.

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