JP2006298063A - Vehicle creep control apparatus and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To relieve the burden on a driver during driving in a congested state or the like by causing a vehicle having a manual transmission 4 to generate creep torque under suitable conditions. <P>SOLUTION: When the manual transmission 4 is in its neutral position and a clutch 3 is engaged, a motor 10 for driving the rear wheels of a 4WD system, for example, is used to generate creep torque. Also, a creep switch 17 that enables the driver to select whether to permit to generate creep torque is provided so that creep torque is generated only when the creep switch 17 is on. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a creep control device and a control method for a vehicle (manual vehicle) with a manual transmission.

Patent Document 1 discloses that in a vehicle with an automatic transmission, a creep torque is generated by a motor when the engine is stopped during vehicle operation.
JP-A-11-093721

  By the way, a vehicle with an automatic transmission generates creep torque (or has creep torque generating means), but a vehicle with a manual transmission does not generate creep torque (or generates creep torque). It is normal to have no means.

  For this reason, when the manual vehicle is running in a traffic jam, it is necessary to perform delicate clutch operation with gear selection, which increases the burden on the driver.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is an object of the present invention to reduce the burden on a driver during a traffic jam by generating creep torque under suitable conditions in a manual vehicle.

  For this reason, the present invention is configured to generate creep torque when the manual transmission is in the neutral position and the clutch is engaged.

  According to the present invention, if the driver sets the gear position to neutral, it is possible to travel by generating creep torque even when both feet are released. Therefore, it is not necessary to operate the clutch when traveling in a congested vehicle with a manual vehicle, and the burden on the driver is reduced.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a system diagram of a vehicle showing an embodiment of the present invention. This example is an example of a motor 4WD system that includes a motor for driving rear wheels separately from an engine for driving front wheels and is capable of switching between 2WD (two-wheel drive) and 4WD (four-wheel drive).

  The engine (internal combustion engine) 1 is controlled by an electric throttle valve 2 or the like in accordance with a driver's operation of an accelerator pedal.

  The output of the engine 1 is transmitted to a manual transmission 4 operated by a driver by a shift lever (shift knob) through a clutch 3 operated by a driver by a clutch pedal. Then, the front wheels 6 are driven via the front wheel drive shaft 5 by the output of the manual transmission 4.

  Further, a generator 7 driven by the front wheel drive shaft 5 and a motor 10 fed by an electric current line 8 from the generator 7 via an inverter 9 are provided.

  The output of the motor 10 is transmitted to the speed reducer 11. A clutch 12 is provided in the speed reducer 11. Then, the rear wheel 14 is driven via the rear wheel drive shaft 13 by the output of the speed reducer 11.

  The 4WD controller 15 can control the generator 7, control the motor 10 via the inverter 9, and further control the clutch 12 in the speed reducer 11.

  A signal is input to the 4WD controller 15 from a 4WD switch 16 for the driver to selectively switch between 2WD and 4WD. Therefore, when switching from 2WD to 4WD by the 4WD switch 16, the rear wheel 14 is driven by the motor 10 by appropriately operating the generator 7, the inverter 9, and the clutch 12 by the 4WD controller 15, and the engine 1 Together with the driving of the front wheels 6, a 4WD state is obtained.

  In the present embodiment, the creep control device according to the present invention is realized by using the rear-wheel drive motor 10 as a creep torque generation source and providing the 4WD controller 15 with a function as a creep torque control means.

  For this reason, a creep switch 17 that allows the driver to select whether or not to generate creep torque is provided, and the signal is input to the 4WD controller 15. Note that the creep switch 17 can be operated at three positions of OFF, D (ON, forward), and R (ON, backward) so that the traveling direction of the vehicle by creep torque can be selected.

  The 4WD controller 15 includes a clutch sensor 18 that detects the engagement state of the driver operation clutch 3, a shift sensor 19 that detects a shift position (gear position including a neutral position) of the manual transmission 4, and a vehicle speed that detects the vehicle speed. A signal from the sensor 20 or the like is input.

  The 4WD controller 15 is connected to an engine control module (ECM) 21 for electronic control of the engine 1 through a communication line. Various engine control information is also input to the 4WD controller 15.

  Next, creep torque generation control by the 4WD controller 15 will be described with reference to the flowchart of FIG. The creep torque generation control here is basically performed when the manual transmission 4 is in the neutral position and the driver operation clutch 3 is engaged on the assumption that the creep switch 17 is ON. Control to generate torque. The flow in FIG. 2 is repeatedly executed every predetermined time.

  In S1, it is determined whether or not the creep switch 17 is ON, that is, whether or not the driver is permitted (or instructed) to generate creep torque.

  When the creep switch 17 is OFF, the process proceeds to S2, and the target creep torque tTc is set to 0 so that the creep torque is not generated.

  When the creep switch 17 is ON, the target creep torque tTc is calculated in S3 to S11 described later.

  In S3, a target creep torque initial value T0 is set. Since this is reduced later by various corrections, it may be set to a predetermined value as the maximum value of the target creep torque.

  In S4, based on the signal from the shift sensor 19, it is determined whether or not the manual transmission 4 is in the neutral position (N).

  In the case of the neutral position, the process proceeds to S5, and it is determined whether or not the creep switch 17 is on the forward side (D) or the backward side (R).

  In the case of the forward side (D), the process proceeds to S6, and the first correction factor K1 is set to 100%.

  In the case of the reverse side (R), the process proceeds to S7, and the first correction factor K1 is set to -100%. This is because the vehicle is moved backward by creep torque.

  If it is determined in S4 that the position is a non-neutral position (in the case of gear selection), the process proceeds to S8, and the first correction factor K1 is calculated from the gear position.

Specifically, at the first speed, K1 = 80%,
When in 2nd gear, K1 = 60%,
When 3rd speed or higher, K1 = 0%,
When reverse (R), K1 = -60%,
To the extent.

  After the calculation of the first correction factor K1 in S6, S7 or S8, the process proceeds to S9.

  In S9, based on the signal of the clutch sensor 18, the second correction factor K2 is calculated from the degree of engagement (clutch stroke) of the driver operation clutch 3.

Specifically, when the engagement is 100% (separation; no stroke), K2 = 100%,
When engagement is 0% (depression; maximum stroke), K2 = 0%,
In the intermediate region, K2 is continuously or stepwise decreased from 100% to 0% as the degree of engagement decreases (the clutch stroke increases).

  A clutch switch that detects only ON / OFF (presence / absence of engagement) of the clutch 3 is used. When engaged, K2 = 100%. When not engaged, K2 = 0%. May be set.

  In S10, based on the signal from the vehicle speed sensor 20, a third correction factor K3 is calculated according to the vehicle speed. Here, when the vehicle speed is low or low, the second correction factor K3 is set large (to 100%), and when the vehicle speed is high or high, the third correction factor K3 is small (0). %)).

Specifically, when the vehicle speed is 0 km / h, K3 = 100%,
When the vehicle speed is 10km / h, K3 = 100%,
When the vehicle speed is 20km / h, K3 = 75%,
When the vehicle speed is 30km / h, K3 = 25%,
When the vehicle speed is 40km / h or more, K3 = 0%,
To the extent.

  After calculating the first to third correction factors K1 to K3, the process proceeds to S11.

  In S11, the target creep torque tTc is calculated by multiplying the target creep torque initial value T0 by all of the first to third correction factors K1 to K3 as in the following equation.

tTc = T0 × K1 × K2 × K3
After calculating the target creep torque tTc, the process proceeds to S12.

  In S12, a creep torque is generated according to the target creep torque tTc. That is, by appropriately operating the generator 7, the inverter 9, and the clutch 12, the rear wheel 14 is driven by the motor 10 by an amount corresponding to the target creep torque tTc to generate a desired creep torque. Of course, no creep torque is generated when tTc = 0.

  FIG. 3 is a time chart showing an example of creep torque generation.

  If the creep switch 17 is turned on when the gear position is neutral (N) and the clutch is in the engaged state (clutch pedal release state), creep torque is generated, and the vehicle can creep. During creep torque generation, the vehicle speed can be controlled by the brake pedal. Thereafter, when shifting to normal running, the clutch is temporarily disengaged and the gear position is shifted to the first speed (1st) and then the clutch is engaged. However, when the clutch is disengaged, the creep torque disappears. However, if the clutch is connected with the gear position shifted to the first speed, a certain amount of creep torque is generated, although it is smaller than in the neutral state. This is to eliminate as much as possible the switching discomfort (torque step) between neutral and first gear.

  According to the present embodiment, since the creep torque is generated when the manual transmission 4 is in the neutral position and the clutch 3 is engaged, if the driver sets the gear position to neutral, both feet are released. Even in the state, creep torque is generated to enable traveling. Therefore, it is not necessary to operate the clutch when traveling in a congested vehicle with a manual vehicle, and the burden on the driver is reduced.

  Further, according to the present embodiment, the driver's intention can be reflected by changing the magnitude of the creep torque in accordance with the degree of engagement of the clutch 3.

  In addition, according to the present embodiment, by changing the magnitude of the creep torque according to the vehicle speed, the generation of the creep torque is restricted in a high vehicle speed range where engine braking is required during deceleration, and traffic congestion is reduced. It is possible to control to generate creep torque only in the vehicle speed range.

  In addition, according to the present embodiment, the creep switch 17 that allows the driver to select whether or not creep torque can be generated is provided, and only when the driver permits the generation of the creep torque by the creep switch 17, Since it was made to generate | occur | produce, it can reflect a driver | operator's intention and it can prevent generating creep torque irrespective of a driver | operator's intention.

  Further, according to the present embodiment, the creep switch 17 can select the traveling direction of the vehicle by the creep torque at the neutral position, and according to the selection, the sign of the creep torque to be generated is changed. Therefore, a creep torque can be generated.

  According to the present embodiment, when the manual transmission 4 is in the non-neutral position and the clutch 3 is engaged, the manual transmission 4 is in the neutral position and the clutch 3 is engaged. If the other conditions are the same as the time, a small creep torque is generated, so that it is possible to prevent an uncomfortable feeling of switching between neutral and gear selection. In this case, the magnitude of the creep torque generated when the manual transmission 4 is in the non-neutral position and the clutch 3 is engaged varies depending on the gear position of the manual transmission 4, so that the switching discomfort is felt. It is possible to prevent unnecessary creep torque from being generated on the high speed side where no problem occurs.

  Further, according to the present embodiment, the creep torque is generated by the second drive source different from the engine 1, thereby facilitating control. In this case, the second drive source includes a motor 10 for driving rear wheels separately from the engine 1 for driving front wheels, and a motor four-wheel drive system capable of switching between two-wheel drive and four-wheel drive. By using the motor 12 for driving the rear wheels, creep torque can be generated by effectively using the motor four-wheel drive system.

  In the above embodiment, the creep torque is generated by the second drive source (rear wheel drive motor 10) different from that of the engine 1. However, even if the shift position of the manual transmission 4 is neutral. By installing a mechanism capable of gear engagement, the creep torque may be generated by using the engine 1 as a drive source and the manual transmission 4 by gear engagement with the mechanism.

  FIG. 4 shows an example in which the manual transmission 4 with an automatic gear selection mechanism capable of gear engagement is used even when the shift position is neutral, the shift position by the shift knob 41 is neutral, and the clutch 3 is engaged. When the creep switch is turned on, even if the shift position is neutral, the gear is engaged (for example, put into the first speed) by the shift actuator 42 to generate the creep torque using the engine 1 as a drive source. .

System diagram of a vehicle (motor 4WD system) showing an embodiment of the present invention Flow chart of creep torque generation control Time chart showing an example of creep torque generation The figure which shows the example using the manual transmission with an automatic gear selection mechanism as other embodiment.

Explanation of symbols

1 engine
2 Electric throttle valve
3 Clutch
4 Manual transmission
5 Front wheel drive shaft
6 Front wheels
7 Generator
8 Current line
9 Inverter
10 Motor
11 Reducer
12 Clutch
13 Rear wheel drive shaft
14 Rear wheel
15 4WD controller
16 4WD switch
17 Creep switch
18 Clutch sensor
19 Shift sensor
20 Vehicle speed sensor
21 ECM

Claims (11)

In a vehicle including, as a drive source, an engine connected to a manual transmission having a neutral position via a driver operation clutch,
A creep control device for a vehicle, comprising creep torque control means for generating creep torque when the manual transmission is in a neutral position and the clutch is engaged.   2. The vehicle creep control device according to claim 1, wherein the creep torque control means changes the magnitude of the creep torque in accordance with the degree of engagement of the clutch.   The vehicle creep control device according to claim 1 or 2, wherein the creep torque control means changes a magnitude of the creep torque in accordance with a vehicle speed.   A creep switch that allows a driver to select whether or not creep torque can be generated is provided, and the creep torque control means is operated only by the creep switch when the driver permits generation of creep torque. The creep control device for a vehicle according to any one of claims 1 to 3.   5. The creep switch is capable of selecting a traveling direction of a vehicle based on creep torque at a neutral position, and changes the sign of the creep torque generated by the creep torque control means according to the selection. Vehicle creep control device.   The creep torque control means is configured such that when the manual transmission is in a non-neutral position and the clutch is engaged, the manual transmission is in a neutral position and the clutch is engaged. 6. The vehicle creep control device according to claim 1, wherein a small creep torque is generated.   The magnitude of creep torque generated when the manual transmission is in a non-neutral position and the clutch is engaged is changed according to the gear position of the manual transmission. The creep control device for a vehicle as described.   The vehicle creep control device according to any one of claims 1 to 7, wherein the creep torque is generated by a second drive source different from the engine.   The second drive source includes a motor for driving rear wheels separately from an engine for driving front wheels, and is a motor four-wheel drive system capable of switching between two-wheel drive and four-wheel drive. 9. The vehicle creep control device according to claim 8, wherein the vehicle creep control device is a motor.   The manual transmission is equipped with a mechanism capable of gear engagement even when the shift position is neutral, and the creep torque is generated by gear engagement with the engine using the engine as a drive source. The creep control device for a vehicle according to any one of claims 1 to 7, wherein In a vehicle including, as a drive source, an engine connected to a manual transmission having a neutral position via a driver operation clutch,
A creep control method for a vehicle, wherein creep torque is generated when the manual transmission is in a neutral position and the clutch is engaged.

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