JP3545136B2 - Electronic control unit for internal combustion engine - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention is applied to automobiles. The present invention relates to an improvement in a control device for controlling a flow rate of fuel supplied to an internal combustion engine by an electronic circuit in accordance with an amount of depression of an accelerator pedal. In particular, the present invention relates to fuel flow control during low-speed rotation of an internal combustion engine. The present invention relates to an application of isochronous control for increasing a fuel supply amount at a low speed rotation of an internal combustion engine. The present invention is suitable for use in an internal combustion engine equipped with a turbocharger (TI). The present invention relates to a technology for rational use with a slope start assist device.
[0002]
[Prior art]
The internal combustion engine has been advanced so that a large output can be obtained with a small internal combustion engine having a small displacement. For this reason, a turbo-charging means (TI) is provided. However, in an internal combustion engine having the turbo-charging means, the output torque at a low rotation speed is small because the turbo mechanism does not work effectively at a low rotation speed. . In particular, in the case of a cargo diesel engine, when starting up a slope when the load is heavy, the rotation speed of the internal combustion engine may drop at the moment the clutch is engaged, and sufficient torque required for starting may not be obtained. is there.
[0003]
FIG. 7 is a diagram showing characteristics of the output torque of the diesel engine when the rotation speed is extremely low. In a general internal combustion engine (NA), a constant output torque can be obtained even when the rotation speed is reduced to some extent. However, in an internal combustion engine having a turbocharger (TI), the output is extremely low at a low rotation speed (for example, 700 rpm or less). There is a characteristic that the torque suddenly decreases.
[0004]
For this reason, in the electronic control device that controls the fuel flow rate of the internal combustion engine, when the load on the internal combustion engine is reduced and the engine rotation speed falls below a certain value, the fuel supply amount is reduced with respect to the normal accelerator opening degree control characteristic pattern control. Techniques have been developed to control it to increase rapidly and maintain the target rotation. This is called isochronous control. The isochronous control of the internal combustion engine when the vehicle starts moving is disclosed in, for example, JP-A-61-196831 and JP-A-5-263687.
[0005]
FIG. 8 is a diagram for explaining a control pattern of the conventional isochronous control. This figure shows the control pattern of the fuel flow rate with respect to the engine speed. In the normal control mode, the curve shown by the solid line is controlled. However, when the engine speed drops to x while the vehicle speed is zero or almost zero, the diagram becomes The injection amount on the line as shown by the thick line is taken. This is isochronous control. When the isochronous control is set, sufficient fuel supply is performed when the rotational speed drops momentarily, the output torque of the internal combustion engine increases, and so-called engine stall can be avoided. It is.
[0006]
[Problems to be solved by the invention]
The present inventors have performed a number of tests to apply this isochronous control to a practical vehicle. A load corresponding to the maximum load was loaded, and the start running test on various road conditions was performed after setting the isochronous control in the internal combustion engine control device. The test was performed under various conditions of isochronous control.
[0007]
As a result, it was found that when the isochronous control was used, the starting characteristics of the ascending slope were certainly improved, but there were some inconveniences. One of them is a road surface condition in which there is a downhill slope immediately after starting on an uphill slope. This occurs, for example, on road surfaces that cross railway crossings. This is a scene in which the vehicle stops once immediately before a railroad crossing, and when the vehicle is started by starting on a sloping road due to an uphill gradient, the road surface immediately crosses the railroad crossing and becomes a downhill. Such road surface conditions are often present on actual roads. In such a road surface condition, the isochronous control is activated at the time of starting, and even if the rotation speed of the engine becomes low, fuel is rapidly supplied and the vehicle starts smoothly. However, immediately after the start, the vehicle goes downhill and the driver feels that it is difficult for the driver to apply the brakes. It has been found that such a situation is a situation that can frequently occur under actual road driving.
[0008]
Further, in the conventional isochronous control, as described in FIG. 8, the control characteristic is constant as represented by a constant curve, and it has been found that this is insufficient for various situations. That is, the isochronous control cannot be effectively used up to a higher engine rotation speed or a lower rotation speed depending on the magnitude of the road surface gradient. It has been found that if this is set according to the degree of the road surface gradient, the internal combustion engine can be more reasonably controlled.
[0009]
Furthermore, the inventors have experienced that when this isochronous control is used in combination with a slope start assist device, the vehicle starts to be extremely smooth, and that the characteristics of the slope start assist device can be effectively used in ordinary road running. I knew I could do it.
[0010]
Regarding the combined use with the hill start assistance device, the road surface is not necessarily only a dry road, so further experiments were conducted in order to know in detail how the road surface condition would be affected by the change. As a result, on a frozen road, when the isochronous control mode is set, when the rotational speed of the wheel decreases, the rotational speed increases to maintain the target rotation, and the road surface is polished and slippery. I found out.
[0011]
This is contrary to the fact that the rotational speed of the wheels must be suppressed on a slippery road surface, and in such a situation, it is conceivable to prohibit the isochronous control mode. In order to automatically perform this prohibition operation, the wheel slip is detected and then released by detecting the slip, and even if the road surface is made slippery and the rotation speed is reduced, the purpose of the original slope start assist operation is Cannot be reached.
[0012]
Also, passages may be dug down or raised to provide a flat approach to the truck for loading and unloading platforms. It has been pointed out that it is inconvenient to automatically set the isochronous control mode in such a passage due to the inclination of the vehicle. That is, in the vicinity of a platform having a structure in which such a passage has a steep slope, when the vehicle is finely moved by the first forward speed and the reverse for loading and unloading, the output from the gradient sensor is followed. It has been pointed out that the isochronous control mode automatically increases the rotation speed of the wheels against the driver's will, giving a sense of incongruity and sometimes making clutch control difficult.
[0013]
The present invention has been made in such a background, and an object of the present invention is to provide a control device that rationally controls an internal combustion engine having a small output torque during low-speed rotation. SUMMARY OF THE INVENTION It is an object of the present invention to provide a control device for setting an isochronous control mode only when necessary. SUMMARY OF THE INVENTION It is an object of the present invention to provide a control device for setting an isochronous control mode to a necessary degree according to a degree of a road surface gradient. An object of the present invention is to provide a control device that does not accelerate the vehicle against the driver's will. The present invention aims to improve driving safety. An object of the present invention is to improve conventional isochronous control. Another object of the present invention is to provide a control device that can effectively use the slope start assist device. An object of the present invention is to provide a control device that can select the isochronous control mode characteristic by manual operation and maintain running stability on a slippery road surface such as an icy road, regardless of the output of the gradient sensor. SUMMARY OF THE INVENTION It is an object of the present invention to provide a control device that automatically sets an optimal isochronous control mode characteristic when a vehicle moves at a low speed irrespective of an output of a gradient sensor and does not give a feeling of strangeness to a driving operation.
[0014]
[Means for Solving the Problems]
Since the output of the internal combustion engine provided with the turbocharger (TI) suddenly decreases at an extremely low rotational speed, when the load is applied to the internal combustion engine and the engine rotational speed indicates a value equal to or lower than a certain value, the internal combustion engine normally operates. Is switched from the normal control mode according to the control characteristic pattern to the isochronous control mode in which the fuel supply amount is rapidly increased. The present invention is characterized in that when switching to the isochronous control mode, a road surface gradient in the traveling direction of the vehicle is detected, and the detection output indicates an upward gradient exceeding a predetermined value (α). .
[0015]
Further, according to the present invention, the target rotation speed of the internal combustion engine for setting the isochronous control mode can be changed in a stepwise manner according to the magnitude of the upward gradient indicated by the gradient sensor. This is achieved, for example, by setting an isochronous control characteristic curve so that the rotational speed of the internal combustion engine is optimum for each gradient according to the gradient, and using this as a control map, the fuel supply control according to the road surface gradient at that time is performed. (See FIG. 3). By providing a plurality of control curves in this manner, the isochronous control can be effectively used over a wide range from a low rotation speed to a high rotation speed, and the internal combustion engine can be rationally controlled.
[0016]
By performing optimal isochronous control on a snowy road or a dry road when there is an ascending slope from a flat road surface, it is more convenient to use the device together with a slope start assist device.
[0017]
In other words, if the predetermined value is set to zero gradient during a pause at a traffic light or when driving on a congested road or the like, the stop and start can be performed smoothly even with almost no operation of the accelerator pedal. become. As a result of an actual driving test, it was found that the slope start assist device was extremely convenient and easy to use by using the present invention together.
[0018]
On dry roads, as described above, the isochronous control mode is set to a necessary degree according to the degree of road surface gradient, and stable running can be performed.On a frozen road where slip is likely to occur, the isochronous control mode is set. Wheels may spin when set. In such a case, it is desirable to release the isochronous control mode.However, if this release operation is to be automatically performed by the control system, the idle rotation of the wheels is detected and then released. Not preferred. To cope with this, an operation switch is provided, and the operation switch is operated at the discretion of the driver to set the isochronous control mode having predetermined characteristics. This makes it possible to easily perform clutch control when traveling on an icy road, and to enhance traveling safety.
[0019]
In addition, during the driving operation of the vehicle, the vehicle may be moved at a speed just before stopping, such as when wearing a platform. The gear position at this time is set at the first forward speed and the reverse position. In the case of such a driving operation as well, it is desirable to select and set a characteristic specific to the isochronous control mode. In the present invention, a gear position sensor is provided, and the isochronous control mode characteristic is selectively set when the output of the gear position sensor indicates the first speed or the reverse position. As a result, the clutch control performed by the driver can be facilitated, and uncomfortable feeling due to an increase in the rotation speed can be eliminated.
[0020]
When the gradient sensor shows a gradient smaller than a predetermined value and smaller than a predetermined value (including a gradient of zero and a downward gradient), the condition of the isochronous control mode is not satisfied, so that the isochronous control mode is forcibly released and normal control is performed. Transition to mode. This eliminates unnecessary acceleration of the vehicle.
[0021]
The device of the present invention can be used together with a slope start assist device. In the operation of the slope start assist device, the clutch pedal is operated for the first predetermined stroke S. ₁ In the above depressed state, the clutch pedal is moved to the second predetermined stroke S after the transmission is engaged in the starting gear or the reverse gear. ₂ (S ₂ <S ₁ ) Automatically releases the brake when it is returned to Therefore, by using the present invention together, the isochronous control is executed when the slope goes uphill together with the slope start assist operation, so that the fuel supply is automatically increased at the start and the characteristics of the slope start assist device are effectively used. Can be used for
[0022]
Further, in a vehicle provided with the second reverse speed, it is desirable that the characteristic of the isochronous control mode is selectively set only at the first reverse speed position.
[0023]
BEST MODE FOR CARRYING OUT THE INVENTION
[0024]
【Example】
Next, embodiments of the present invention will be described with reference to the drawings.
[0025]
(First embodiment)
FIG. 1 is a block diagram showing a configuration of a main part of the first embodiment of the present invention.
[0026]
The first embodiment of the present invention includes a rotational speed sensor 2 for detecting a rotational speed of an internal combustion engine 1, a vehicle speed sensor 3 for detecting a vehicle speed, an accelerator pedal sensor 4 for detecting an amount of depression of an accelerator pedal 21, and a transmission. A neutral position sensor 5 for detecting that the vehicle 25 is in a neutral position, a gradient sensor 6 for detecting a road surface gradient with respect to a traveling direction of the vehicle, a clutch stroke sensor 7 for detecting a depression stroke of a clutch pedal 23, and a brake pedal 22 , A clutch oil pressure switch 9 for detecting whether or not the clutch pedal 23 is depressed, an output of each of the sensors and the switches, and internal combustion in accordance with the output of the accelerator pedal sensor 4. A control circuit 10 for controlling the flow rate of fuel supplied to the engine 1 is provided.
[0027]
Here, the control circuit 10 does not necessarily need to be an independent circuit, and can be realized by providing a circuit for performing substantially the following control in a computer circuit.
[0028]
Further, the control circuit 10 includes means for setting an isochronous control mode for increasing fuel supply when the vehicle speed is equal to or lower than a predetermined value and the rotation speed of the internal combustion engine 1 decreases, and the output of the gradient sensor 6 exceeds a predetermined value. Means for setting the isochronous control mode on the condition that the ascending gradient is indicated, and means for changing the target rotational speed of the internal combustion engine 1 for setting the isochronous control mode in accordance with the magnitude of the ascending gradient indicated by the output of the gradient sensor 6; Means for forcibly canceling the isochronous control mode when the gradient sensor 6 indicates a gradient (including a downward gradient) smaller than the predetermined value and equal to or smaller than a predetermined value.
[0029]
Here, the operation of the first embodiment of the present invention will be described. FIG. 2 is a flowchart showing the flow of the control operation in the first embodiment of the present invention.
[0030]
The control circuit 10 controls the operation of the isochronous control mode, takes in the output from the vehicle speed sensor 3, and sets the current vehicle speed v to the set value v ₀ It is determined whether or not: Vehicle speed v is set value v ₀ If below, the output from the gradient sensor 6 is taken in, and if the transmission 25 is not in the neutral position, the gradient value is held.
[0031]
Subsequently, the output from the clutch stroke sensor 7 is taken in a state where the gradient value is held, and the position state of the clutch is determined. When the position of the clutch is at P2 indicating the position immediately before the meet set by the driver and the gradient value is an uphill, the isochronous control mode is set, and the control is executed according to the isochronous control curve shown by the thick solid line in FIG. This control is to increase the fuel supply in order to prevent the rotation speed of the internal combustion engine 1 from decreasing at the time of the clutch meet, and to increase the magnitude of the upward gradient indicated by the output of the gradient sensor 6, for example, 3%, 6%, 10%. ,... Are performed in accordance with a characteristic curve determined in accordance with.
[0032]
When the isochronous control curve according to the magnitude of the upward gradient is selected, the output from the vehicle speed sensor 3 is taken in again to check the vehicle speed. If the vehicle speed is indicated, the fuel injection amount is read from the rack position or the engine control circuit injection amount instruction value, and it is determined whether the fuel injection amount is equal to or greater than a preset injection amount. If the injection amount is equal to or more than the same injection amount, it indicates an acceleration state, so the output from the brake switch 8 is taken in, and it is determined whether or not the brake pedal 22 is depressed. If the brake pedal is not depressed, the output from the clutch hydraulic switch 9 is taken in, and it is determined whether or not the clutch 24 is at the position P3 in the meet state. If the clutch is at the position P3 in the meet state, while continuing the isochronous control mode, a comparison is made between the injection amount instruction value by the driver's intention to take in the output from the accelerator pedal sensor 4 and the injection amount instruction value by the isochronous control. Then, the large value is instructed to the engine as the final injection amount. Hereinafter, the same operation is repeated.
[0033]
If it is not indicated that the fuel injection is equal to or greater than the idling injection amount, and if the condition value for which the start has been completed in advance such as that the brake pedal 22 is depressed or the clutch 24 is not at the position P3 of the meet state, the isochronous control Since traveling is unnecessary, the control mode is released, the gradient value is reset, and control is returned to the original.
[0034]
When the isochronous control mode is released, the normal control mode is automatically set, and the normal traveling control is performed according to one of the plurality of control curves indicated by the thin solid lines in FIG. For example, assuming that the vehicle has a fuel flow rate at point A on the isochronous control curve shown in FIG. 3 when the vehicle is on an uphill gradient of 3%, the start completion condition is satisfied and the normal control is performed when the isochronous control mode is released. Since the mode is shifted, the fuel flow rate at the point B on the normal control curve is given. This prevents the acceleration from continuing when the vehicle is in a flat state or when the vehicle has a negative gradient, so that stable traveling can be performed.
[0035]
(Second embodiment)
FIG. 4 is a block diagram showing a configuration of a main part of the second embodiment of the present invention.
[0036]
In the second embodiment of the present invention, a gear position sensor 15 for detecting the gear position of the transmission 25 is provided in the configuration of the first embodiment, and a slope start assist device 30 is provided. The slope start assist device 30 has already been put to practical use by the present applicant as disclosed in JP-A-7-40816 and JP-A-7-101322. This device comprises a front tank 31, a rear tank 32 and a reserve tank 33, a front brake valve 34 and a rear brake valve 35 for supplying the air pressure stored in the front tank 31 and the rear tank 32 by operating the brake pedal 22, A stop lamp switch 36 for turning on a stop lamp when air pressure is supplied from the valve 34 and the rear brake valve 35, and an opening / closing operation performed according to a control signal from the control circuit 10 to apply air pressure to the front brake booster 37 and the rear brake booster 38. And an electromagnetic valve 39 for supplying the pressure. Further, the control circuit 10 sends a control signal for holding the brake pressure to the solenoid valve 39 when the output of the brake switch 8 indicates the braking state and the vehicle speed is zero, and holds the brake pressure. Means for transmitting a control signal for releasing the brake pressure when the clutch stroke sensor 7 detects a predetermined stroke when the clutch stroke sensor 7 detects a predetermined stroke.
[0037]
That is, while the brake pressure is being applied, the clutch pedal 23 is moved to the first predetermined stroke (S ₁ After the gear is depressed deeper and the gear is shifted to the forward start position or the reverse position, the clutch pedal 23 is moved to the second stroke S. ₂ (S ₂ <S ₁ ), The brake pressure is automatically released when the predetermined stroke is reached.
[0038]
Next, the operation of the second embodiment of the present invention in which the slope start assist device 30 is used together will be described. FIG. 5 is a flowchart showing the flow of the control operation in the second embodiment of the present invention.
[0039]
The control circuit 10 confirms whether or not the operation by the slope start assist device 30 is being executed. If the operation is executed, the control circuit 10 performs the same operation as in the first embodiment, and confirms that the output of the gradient sensor 6 is an upward gradient. If so, the isochronous control mode is set. In the state where the isochronous control mode is set, it is determined whether or not the slope start assist operation is continued, and if it is in the continued state, the operation is released, and control is performed according to the isochronous control mode until the condition to be released is satisfied. . If the output of the gradient sensor 6 indicates that the vehicle is on a downhill, the normal control mode is continued, the gradient value is reset, and control is returned to the original. Thereby, only the slope start assist operation is effectively performed.
[0040]
The hill start assistance device 30 releases the foot from the brake pedal 22 when the brake pressure exceeds a predetermined value and the vehicle speed becomes zero, and when it is detected that there is a gradient in the traveling direction of the vehicle. Also automatically holds the brake pressure. When the driver sets the transmission 25 to the start position, engages the clutch 24, and depresses the accelerator pedal 21, the brake pressure is automatically released at the most appropriate timing, and the braking state is released. Therefore, the driver can easily perform the hill start operation without involving the operation of the parking brake.
[0041]
When used together with such a slope start assistance device, the isochronous control is automatically executed when traveling on an uphill because the gradient sensor detects the upward gradient, and the fuel supply amount is increased. If the condition is satisfied, the system immediately switches to the normal control mode to limit the fuel supply, so that it is possible to avoid increasing the engine speed on roads that do not require acceleration and making it difficult to apply the brakes. You.
[0042]
(Third embodiment)
FIG. 6 is a block diagram showing a configuration of a main part of the third embodiment of the present invention.
[0043]
In the third embodiment of the present invention, in addition to the configuration of the second embodiment, an operation switch 16 which is opened and closed by operation between the gradient sensor 6 and the control circuit 10 is provided. Means are provided for setting the isochronous control mode having predetermined characteristics regardless of the output of the gradient sensor 6 when turned on. As an example, the characteristic having a gradient of 3% shown in FIG. 3 is fixedly selected. The operation switch 16 is arranged on an operation panel provided in a driver's seat.
[0044]
When starting and running on an icy road, it is necessary to reduce the rotational speed of the wheels as much as possible. In such a situation, it is not preferable that the isochronous control mode is set, because an operation of increasing the rotation speed of the wheel is performed when the speed becomes low. The control circuit 10 can release the isochronous control mode by detecting the slip of the wheel, and this output has no effect. However, the release after the wheel slips has no effect, and makes the clutch control of the driver difficult.
[0045]
In the third embodiment, it is left to the driver to determine whether or not the wheels are slipping. If the road surface is frozen, the operation switch 16 is operated, and the control circuit 10 receives the output and receives the output. Also, the isochronous control mode of a predetermined characteristic (in this case, the characteristic of the gradient of 3% in FIG. 3) is set regardless of the output of the gradient sensor 6. As a result, isochronous control that does not deteriorate the running conditions on the frozen road can be performed in a safe state. Other operations are performed in the same manner as in the second embodiment.
[0046]
(Fourth embodiment)
The fourth embodiment of the present invention is constructed in the same manner as the second embodiment shown in FIG. 4, and determines the control circuit 10 when the output of the gear position sensor 15 indicates the first forward speed or the reverse, regardless of the output of the gradient sensor 6. Means are provided for automatically setting the isochronous control mode having the determined characteristics.
[0047]
During the operation of the vehicle, a steep hill advance and retreat are performed at a speed just before the stop, such as laying down on a platform for loading and unloading luggage. The forward gear position at this time is set to the first speed. In such a case, if the isochronous control mode is set according to fixed characteristics, control for increasing the rotation speed of the wheels is performed, and clutch control becomes difficult.
[0048]
The fourth embodiment is different from the third embodiment in that when the control circuit 10 indicates that the output of the gear position sensor 15 indicates the first forward speed or the reverse speed, the isochronous control mode is most suitable. This is automatically set so as to be performed according to a curve, so that a decrease in operability such as clutch control can be avoided. Other operations are performed in the same manner as in the second embodiment.
[0049]
【The invention's effect】
As described above, according to the present invention, since the isochronous control mode can be set only when necessary, it is possible to rationally control the internal combustion engine having a small output torque during low-speed rotation. In addition, since the isochronous control mode is set to a necessary degree corresponding to the degree of the road surface gradient, it is possible to prevent the vehicle from being accelerated against the driver's will, thereby improving driving safety. Can be improved. Furthermore, since it can be used rationally together with the slope start assist device, the slope start assist operation can be effectively used.
[0050]
In the present invention, the setting of the characteristics of the isochronous control mode can also be performed by a driver's manual operation, and it is possible to avoid deteriorating the starting condition by leaving the driving on the frozen road to the driver's judgment. Can be. In addition, when a vehicle operation such as repeating forward and backward movements at the first speed is performed, the associativity control mode characteristic is automatically set, so that it is possible to avoid a decrease in operability including clutch control.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a main part of a first embodiment of the present invention.
FIG. 2 is a flowchart showing a flow of a control operation in the first embodiment of the present invention.
FIG. 3 is a diagram showing an isochronous control curve and a normal control curve in the first embodiment of the present invention.
FIG. 4 is a block diagram showing a configuration of a main part of a second embodiment of the present invention.
FIG. 5 is a flowchart showing a flow of a control operation according to the second embodiment of the present invention.
FIG. 6 is a block diagram showing a configuration of a main part of a third embodiment of the present invention.
FIG. 7 is a diagram showing characteristics of output torque when the rotation speed of the diesel engine is extremely low.
FIG. 8 is a view for explaining a control pattern of conventional isochronous control.
[Explanation of symbols]
1 Internal combustion engine
2 Rotation speed sensor
3 Vehicle speed sensor
4 accelerator pedal sensor
5 Neutral position sensor
6 Gradient sensor
7 Clutch stroke sensor
8 Brake switch
9 Clutch hydraulic switch
10 Control circuit
11 Electronic governor control circuit
15 Gear position sensor
16 Operation switch
21 accelerator pedal
22 brake pedal
23 Clutch pedal
24 clutch
25 transmission
30 Slope start assist device
31 Front tank
32 rear tank
33 Reserve tank
34 Front brake valve
35 Rear brake valve
36 Stop lamp switch
37 Front brake booster
38 Rear brake booster
39 solenoid valve

Claims (4)

An internal combustion engine provided with turbocharging means, comprising: a rotational speed sensor, a vehicle speed sensor, an accelerator pedal sensor, and an output of each of the sensor sensors of the internal combustion engine. A control circuit for controlling the flow rate of fuel supplied to the vehicle, the control circuit including means for setting an isochronous control mode for increasing fuel supply when the vehicle speed is equal to or lower than a fixed value and the rotational speed of the internal combustion engine is reduced. In the electronic control device of the internal combustion engine
Equipped with a gradient sensor that detects a road surface gradient with respect to the traveling direction of the vehicle,
The control circuit selects an isochronous control characteristic curve determined according to the magnitude of the upward gradient indicated by the output of the gradient sensor when the gradient sensor output indicates an upward gradient exceeding a predetermined value, and performs the isochronous control. An electronic control unit for an internal combustion engine, comprising: means for changing a fuel injection amount according to a characteristic curve. 2. An operation switch which is operated by a driver in accordance with a state of a road surface, and means for performing control according to an isochronous control characteristic curve having a predetermined gradient by operating the operation switch regardless of the output of the gradient sensor. An electronic control unit for an internal combustion engine according to claim 1. 2. The internal combustion engine according to claim 1, further comprising a gear position sensor, wherein when the output of the gear position sensor indicates the first forward speed, control is performed according to a predetermined isochronous control characteristic curve regardless of the output of the gradient sensor. Engine electronic control unit. 2. The internal combustion engine according to claim 1, further comprising a gear position sensor, wherein when the output of the gear position sensor indicates reverse, control is performed according to a predetermined isochronous control characteristic curve regardless of the output of the gradient sensor. Electronic control unit.

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