JPH1075505A - Auxiliary driving force controller of vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To generate an arbitrary creeping force without the influence of the idling revolution of an engine and control a vehicle velocity in the creeping delicately. SOLUTION: Main driving wheels Wf are driven by an engine E through an automatic transmission 1 and, at the same time, auxiliary driving wheels Wr are driven by a motor M. A torque is generated by the motor M in accordance with the movement of a brake pedal and the auxiliary driving wheel Wr are turned by the torque to make a car creep. The motor M generates a torque also immediately after an acceleration pedal is stepped in and the driving force of the engine E is assisted by the torque to improve the starting performance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a vehicle capable of traveling by transmitting the driving force of an engine and the driving force of an auxiliary driving source to wheels.

[0002]

2. Description of the Related Art In a vehicle equipped with an automatic transmission, a torque generated by a torque converter when a foot is released from an accelerator pedal is used as a so-called creep torque. The characteristic of the braking force for controlling the vehicle speed during creep running is to intentionally sharply increase the braking force with respect to the brake pedal force, for example, in order to receive the creep force at the time of stopping at a traffic light with a good feeling.

[0003]

However, in the prior art in which a creep force is generated by an engine, since the creep force is determined by the idling speed, it is difficult to delicately control the vehicle speed during creep running. In addition, if the idle speed changes suddenly due to a change in the load of an auxiliary device such as an air conditioner, there is a problem that the vehicle speed during creep running changes against the driver's intention. Further, even if an attempt is made to control the vehicle speed during creep running with the brake pedal force, it is difficult to delicately control the vehicle speed because the rise of the brake force with respect to the brake pedal force is set to be sharp as described above.

[0004] The present invention has been made in view of the above circumstances, and is intended to generate an arbitrary creep force without being affected by the idling speed of the engine so that the vehicle speed during creep running can be finely controlled. Aim.

[0005]

According to the first aspect of the present invention, when the brake pedal is operated when the accelerator pedal is not operated, the driving force of the auxiliary drive source changes, so that it is affected by the idle speed of the engine. Without causing the auxiliary drive source to generate a creep torque of any magnitude, the vehicle speed during creep running can be finely controlled.

According to the second aspect of the present invention, the auxiliary driving source generates a driving force in accordance with the operation amount of the accelerator pedal.
The starting performance can be improved by assisting the driving force of the engine with the driving force of the auxiliary driving source.

According to the third aspect of the invention, when the creep running is performed by the driving force of the auxiliary driving source, the engine during idle operation is separated from the wheels and the engine load is reduced, so that the fuel consumption is reduced. Noise can be prevented.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described based on embodiments of the present invention shown in the accompanying drawings.

1 to 12 show an embodiment of the present invention. FIG. 1 is an overall configuration diagram of a hybrid vehicle, FIG. 2 is an enlarged view in two directions of FIG. 1, and FIG. -3 line sectional view,
4 is a sectional view taken along line 4-4 of FIG. 3, FIG. 5 is a sectional view taken along line 5-5 of FIG. 4, FIG.
FIG. 7 is an explanatory diagram of the operation during reverse running corresponding to FIG. 5, FIG. 8 is a flowchart of the main routine, and FIG.
10 is a flowchart of a subroutine of FIG.
13 is a flowchart of a subroutine of step S14, and FIG. 12 is a map for searching for a motor torque.

As shown in FIG. 1, the hybrid vehicle includes a pair of left and right main driving wheels Wf, Wf at a front portion of the vehicle body, and a pair of left and right auxiliary driving wheels Wr, Wr at a rear portion of the vehicle body. The driving force of the engine E is transmitted to the left and right main driving wheels Wf, Wf via the automatic transmission 1 and the differential 2, and the left and right auxiliary driving wheels Wf
r and Wr are driven by a pair of left and right motors M and M, respectively. An electronic control unit U including a microcomputer is provided between a battery 4 charged by a generator 3 driven by an engine E and motors M, M driven by the battery 4. The electronic control unit U
Based on the accelerator pedal operation amount, the side brake switch, the shift position of the transmission 1, the vehicle speed, the engine speed, the ignition switch, the brake pedal operation amount, and the power generation state of the generator 3, the shift of the transmission 1 and the auxiliary It controls the driving of the motors M, M connected to the driving wheels Wr, Wr, and the operation of alarm means 6 such as a lamp or a buzzer that alerts the driver when an abnormality occurs.

Next, the auxiliary drive wheel W will be described with reference to FIGS.
The structure of the driving force transmission system for r and Wr will be described. Since the structure of the driving force transmission system of the left and right auxiliary driving wheels Wr is the same, the structure of the driving force transmission system of the left auxiliary driving wheel Wr will be described as an example.

A gear box 12 is provided at the rear end of a suspension arm 11 which supports the auxiliary drive wheel Wr so as to be vertically swingable on the vehicle body.
The housing 14 of the motor M is connected to the housing 3 through the third housing 3. The axle 15 of the auxiliary drive wheel Wr is supported at one end by a ball bearing 16 on the suspension arm 11 and at the other end by a pair of ball bearings 17 on the gear box 12. Gear box 12
A worm shaft 19 supported via a pair of ball bearings 18, 18 is arranged in the front and rear direction of the vehicle body. 21 mesh. The worm wheel 20 and the worm 21 constitute a worm gear mechanism 22.

The worm 21 of the worm gear mechanism 22
Has a large lead angle of a spiral screw thread engraved on the outer periphery thereof, so that the rotation speed can be reduced and transmitted from the worm 21 side to the worm wheel 20 side. It is also possible to increase the rotation speed and transmit the rotation speed from the side to the worm 21 side. By employing the worm gear mechanism 22 in the driving force transmission system from the motor M to the auxiliary driving wheel Wr, a large reduction ratio is achieved with a minimum number of gears, and the motor M and the driving force transmission system are reduced in size and weight. Can be achieved.

The motor M includes a stator 23 fixed to the inner periphery of the housing 14, the housing 14 and the partition 13.
And an output shaft 25 supported via a pair of ball bearings 24, 24, and a rotor 26 fixed to the output shaft 25. A two-way clutch chamber 27 adjacent to the partition 13 is formed in the gear box 12. In the two-way clutch chamber 27, between a rear end of the worm shaft 19 coaxially opposed and a front end of the output shaft 25 of the motor M. A two-way clutch 28 is provided. The two-way clutch 28
The driving force is transmitted from the motor M side to the auxiliary driving wheel Wr side regardless of whether the motor M rotates forward or backward, and the auxiliary driving wheel Wr rotates forward from the auxiliary driving wheel Wr side to the motor M side. It does not transmit the driving force even if it rotates in the reverse direction.

The two-way clutch 28 includes an inner member 29 fixed to the output shaft 25 of the motor M and a worm shaft 1.
9 and an outer member 30 fixed to the outer member 9. The inner member 29 and the outer member 30 are arranged coaxially,
The tip of the output shaft 25 of the motor M is supported on the inner periphery of the outer member 30 via a ball bearing 33.

On the outer periphery of the inner member 29, there are formed eight cam member sliding surfaces 29 ₁ ... Arranged in a regular octagonal shape, and on the inner periphery of the outer member 30, the cam member sliding surfaces 29 _1. ... circular roller guide surface 30 ₁ facing is formed. The upper surfaces of the eight cam members 31 formed in a substantially trapezoidal shape are slidably in contact with the eight cam member sliding surfaces 29 ₁ , and the oblique sides of the adjacent cam members 31. Are in contact with each other. The cam member 31 ... lower base of the concave cam surface 31 ₁ ..., 8 between which the cam surfaces 31 ₁ ... and the roller guide surface 30 ₁ of the outer member 30
Are arranged. When the driving force is not transmitted between the inner member 29 and the outer member 30, the eight cam member sliding surfaces 29 _1, ..., The cam members 31 and the rollers 32 are radially aligned, respectively. a slight gap is formed between the roller 32 ... and the roller guide surface 30 ₁ (see FIG. 5).

When the driving force is transmitted from the auxiliary driving wheel Wr to the motor M, that is, when the driving force is transmitted from the outer member 30 to the inner member 29, as shown in FIG. 32 ... a two-way clutch 28 by a gap formed between the roller guide surface 30 ₁ is turned OFF to cut off the transmission of the driving force. The OFF state of the two-way clutch 28 similarly occurs when the vehicle is traveling forward or backward, that is, when the outer member 30 rotates in either the arrow A direction or the A ′ direction. I do.

When the driving force is transmitted from the motor M to the auxiliary driving wheel Wr during the forward running of the vehicle,
When the driving force is transmitted from the inner member 29 rotating in the direction of arrow B to the outer member 30, the cam members 31 slide on the cam member sliding surfaces 29 ₁ of the inner member 29 in the direction of arrow B '. . As a result, the cam surfaces 31 ₁ of the cam members 31 and the roller guide surfaces 30 ₁ of the outer member 30.
Between the inner member 29 and the roller 32.
Is transmitted to the outer member 30 via the cam members 31 and the rollers 32.

Conversely, when the driving force is transmitted from the motor M side to the auxiliary driving wheel Wr side when the vehicle is traveling in reverse, the driving force is transmitted from the inner member 29 rotating in the direction of arrow C in FIG. When transmitted, the cam members 31 ...
Slides on the cam member sliding surfaces 29 ₁ ... Of the inner member 29 in the direction of arrow C ′. As a result, the cam surfaces 31 ₁ of the cam members 31 and the roller guide surfaces 30 ₁ of the outer member 30.
Between the inner member 29 and the roller 32.
Is transmitted to the outer member 30 via the cam members 31 and the rollers 32.

As described above, the main drive wheels Wf, Wf are driven by the engine E, and the auxiliary drive wheels Wr, Wr are driven by the motors M,
Since the drive system is driven by M, the drive system by the engine E and the drive system by the motors M and M do not interfere with each other, and the structure of the drive system is simplified.

Next, the operation of the embodiment of the present invention having the above-described configuration will be described with reference to flowcharts.

In the flowchart of the main routine shown in FIG. 8, if the side brake switch is turned off in step S1 and if there is no abnormality in the output of the generator 3 in step S2, the "motor creep control" is executed in step S3. Run. If the side brake switch is ON in step S1, or if the side brake switch is OFF in step S1, step S2
If there is an abnormality in the output of the generator 3 at step S4
To execute the "motor creep forced termination control", and activate the alarm means 6 in step S5. As described above, when the generator 3 fails and the battery 4 cannot be sufficiently charged, the creep running by the motors M and M is terminated, and the consumption of the battery 4 can be avoided. The above controls are continued until the ignition switch is turned off in step S6.

Next, the subroutine of "motor creep control" in step S3 will be described with reference to the flowchart of FIG.

First, in step S11, the absolute value of the vehicle speed V is equal to or less than the first threshold value V ₀ (for example, the vehicle speed of several km / h) shown in FIG. 12, and in step S12, the shift position is set to the “D” position. (Drive position),
When in the "2" position (second speed fixed position) or "L" position (first speed fixed position)
In step S13, "neutral control of transmission 1 (for forward control)" is executed, and in step S14, "motor output control (for forward control)" is executed.

If the shift position is neither the "D" position nor the "2" position or the "L" position in step S12, and if the shift position is the "R" position (reverse position) in step S15, the "transmission" is determined in step S16. 1 neutral control (for reverse control) "and step S
At 17, “motor output control (for reverse drive control)” is executed.
And if the absolute value of the vehicle speed V in step S11 exceeds the threshold value V _0, or step S12, nor "R" position at "L" position also S13 the shift position at the "2" position at "D" position In this case (ie, when the shift position is the “N” position (neutral position) or the “P” position (parking position)), “motor creep forced termination control” is executed in step S18.

Next, the "neutral control of transmission (for forward control)" in step S13 is described with reference to FIG.
0 will be further described.

This "transmission neutral control (for forward control)" is executed when the side brake is off and the forward shift position is selected. Ne is less than a predetermined threshold value Ne ₀ , and the absolute value of the vehicle speed V is less than a second threshold value V ₁ (where 0 ≦ V ₁ ≦ V ₀ ) in step S22, and step S23
If the operation amount of the brake pedal is not zero, the gear position of the transmission is forcibly set to neutral in step S24. On the other hand, steps S21, S22, S
23, that is, the engine speed Ne becomes equal to or more than the threshold value Ne ₀ , the absolute value of the vehicle speed V becomes equal to or more than the second threshold value V ₁ , or the brake pedal operation amount becomes zero. If so, in step S25, the transmission 1 is made to establish a predetermined gear position according to the driving state of the vehicle.

As described above, steps S21, S2
When all of S2 and S23 are NO and the vehicle is not driven by the driving force of the engine E, the transmission is forcibly neutralized, so that the energy loss generated in the torque converter of the transmission 1 is reduced and fuel consumption is reduced. I do. Further, in the conventional vehicle that performs creep running by the engine E, there is a problem that the engine mount is displaced by the creep torque of the engine and the noise in the vehicle interior increases. However, in this embodiment, the transmission 1 is forcibly neutralized during the creep running. Therefore, the generation of the noise is avoided.

Next, the "motor output control (for forward control)" of the step S14, which is executed following the "neutral control of the transmission (for forward control)", will be further described with reference to the flowchart of FIG. .

[0030] a accelerator pedal operation amount is zero in step S31, and if the brake pedal operation amount is a threshold value B ₀ or more in step S32, determines that the driver has no intention to creeping of the vehicle, step In S33, the outputs of the motors M, M are set to zero. In step S31, the accelerator pedal operation amount is zero, and in step S32, the brake pedal operation amount is equal to the threshold value B _0.
If less than, it is determined that the driver intends to cause the vehicle to creep. Then, in step S34, a duty ratio for performing PWM control of the motors M, M is determined, and in step S35, the motors M, M are driven based on the duty ratio to cause the vehicle to travel forward in a creep running. The duty ratio (that is, the creep torque generated in the motors M, M) determined in step S34 is shown as a creep region in the map of FIG.

The "neutral control of transmission (for reverse control)" in step S16 and step S16
The “motor output control (for reverse control)” of Step 17 is substantially the same as the “transmission neutral control (for forward control)” of Step S13 and the “motor output control (for forward control)” of Step S14. Therefore, the overlapping description is omitted. The main difference is that Figure 1
This means that the direction of the creep torque retrieved from the map shown in FIG. 2 is reversed. That is, the motors M,
M generates torque in the forward (forward) direction, whereas the motors M, M generate torque in the reverse (reverse) direction during reverse control.

As described above, since the torque for creeping the vehicle is generated by the motors M, M, the driver can easily control the vehicle without being affected by the idle speed of the engine E. It is possible to surely generate the optimum creep torque that can be obtained. For example, if the threshold value B ₀ of the brake pedal operation amount in FIG. 12 is set to an operation amount at which substantial braking force starts to be generated, the brake pedal operation amount in a creep region smaller than the threshold value B _0. When performing creep running, it is possible to avoid applying a substantial braking force and reduce energy loss. When the brake pedal operation amount exceeds the threshold value B _0, since the creep torque braking force rises with zero, it is possible to stop the vehicle reliably.

Further, as apparent from FIG. 12, when holding the brake pedal operation amount to a small predetermined amount than the threshold value B _0, the vehicle speed V increases gradually by the creep torque. In this case, the creep torque is maintained at a constant value in the initial stage of the increase in the vehicle speed V, and thereafter, the creep torque decreases to zero in accordance with the increase in the vehicle speed V. The vehicle creeps at a constant speed with the propulsion of the vehicle balanced.
In this way, the final vehicle speed during creep running can be controlled by the brake pedal operation amount,
Particularly, the vehicle can be easily moved at a very low speed in a narrow place.

On the other hand, if the operation amount of the accelerator pedal is not zero in step S31, it is determined that the driver has the intention to start the vehicle. And step S
The duty ratio for performing PWM control of the motors M, M is determined at 36, and the vehicle is started forward by starting the motors M, M based on the duty ratio at step S37. The duty ratio (that is, the torque generated in the motors M, M) determined in step S36 is as shown in FIG.
2 is shown as an assist area in the map. At this time, when the accelerator pedal is depressed, step S
Since any one of S21, S22, and S23 becomes YES, the transmission 1 is engaged, and the driving force of the engine E is transmitted to the main drive wheels Wf, Wf.

As is apparent from the map shown in FIG. 12, when the accelerator pedal operation amount exceeds a predetermined value, the torque generated by the motors M and M becomes zero. The assist is provided by the driving force of the motors M and M, and the assist by the motors M and M ends with an increase in the depression amount of the accelerator pedal. As described above, when the accelerator pedal is depressed when the vehicle starts, the motors M, M generate the driving force to assist the driving force of the engine E. Therefore, the use of the area where the speed ratio of the torque converter is large and the energy efficiency is low is not performed. As a result, it is possible to minimize the fuel consumption, thereby contributing to a reduction in fuel consumption. In addition, the starting performance on a low friction coefficient road surface such as a snowy road or on a steep slope is improved.

Although the embodiments of the present invention have been described in detail above, various design changes can be made in the present invention without departing from the gist thereof.

For example, in the embodiment, the front wheels are driven by the engine E and the rear wheels are driven by the motors M, M. However, the positional relationship may be reversed, and the front wheels or the rear wheels may be driven by the engine E. It is also possible to drive with both the motors M and M. Further, the auxiliary drive source is not limited to the motors M and M of the embodiment, and a hydraulic drive unit such as a hydraulic motor or a mechanical drive unit such as a flywheel can be employed. Further, the clutch connected to the auxiliary drive source is the two-way clutch 2 of the embodiment.
It is not limited to 8, and an electromagnetic clutch or a hydraulic clutch can be adopted.

[0038]

As described above, according to the first aspect of the present invention, there is provided the control means for controlling the driving force of the auxiliary driving source according to the operation amount of the brake pedal when the accelerator pedal is not operated. Thus, a creep torque of an arbitrary magnitude is generated in the auxiliary drive source irrespective of the idle speed of the engine, and the vehicle speed during creep running can be delicately controlled.

According to the second aspect of the present invention,
The auxiliary drive source generates driving force according to the amount of operation of the accelerator pedal when the accelerator pedal is operated, so the engine driving force is assisted with the driving force of the auxiliary drive source at the time of starting the vehicle, etc. to improve the starting performance. Can contribute.

According to the third aspect of the present invention,
When the auxiliary drive source generates a driving force according to the operation amount of the brake pedal, the power transmission between the engine and the wheels is cut off, so that the idle load of the engine is reduced to reduce fuel consumption and noise. be able to.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a hybrid vehicle.

FIG. 2 is an enlarged view taken in two directions in FIG. 1;

FIG. 3 is a sectional view taken along line 3-3 in FIG. 2;

FIG. 4 is a sectional view taken along line 4-4 in FIG. 3;

FIG. 5 is a sectional view taken along line 5-5 of FIG. 4;

FIG. 6 is an operation explanatory diagram corresponding to FIG. 5 during forward running.

FIG. 7 is an explanatory diagram of an operation during reverse running corresponding to FIG. 5;

FIG. 8 is a flowchart of a main routine.

FIG. 9 is a flowchart of a subroutine of step S3.

FIG. 10 is a flowchart of a subroutine of step S13.

FIG. 11 is a flowchart of a subroutine of step S14.

FIG. 12 is a map for searching for a motor torque.

[Explanation of symbols]

 E engine M motor (auxiliary drive source) U electronic control unit (control means) Wf main drive wheel (wheel) Wr auxiliary drive wheel (wheel)

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical indication F02D 29/02 (72) Inventor Yasuharu Oyama 1-4-1, Chuo, Wako-shi, Saitama Co., Ltd. Honda Technical Research Institute

Claims (3)

[Claims] In a vehicle capable of traveling by transmitting a driving force of an engine (E) and a driving force of an auxiliary driving source (M) to wheels (Wf, Wr), an operation amount of a brake pedal when an accelerator pedal is not operated And a control means (U) for controlling the driving force of the auxiliary driving source (M) according to the control signal. 2. The auxiliary driving force control device for a vehicle according to claim 1, wherein the auxiliary driving source (M) generates a driving force according to an operation amount of the accelerator pedal when the accelerator pedal is operated. . 3. When the auxiliary driving source (M) generates a driving force according to an operation amount of a brake pedal, power transmission between an engine (E) and wheels (Wf) is shut off. The auxiliary driving force control device for a vehicle according to claim 1.