JPH10252520A - Car speed limit device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve drive performance in passing or the like while ensuring improvement of fuel consumption, by temporarily releasing a car speed limit as necessary. SOLUTION: In a car speed limit device provided with a means a limiting a maximum speed of engine rotation, so as to suppress a car speed to a prescribed limit value or less, by throttling a fuel supply amount of an engine, a means c is provided, which releases a car speed limit only for a prescribed time when any one is decided for performing accelerator operation of prescribed pattern, performing speed change operation, and in an ascending run condition. A means g is provided, which performs engine control, when a release time of car speed limit passes, returning a car speed in the point of this time to a limit value by prescribed deceleration. The release means c of car speed limit, when a specific switch is closed, during this time, releases a car speed limit. The release means c of car speed limit is provided with a means h controlling a buzzer in an operating room so as to generate an alarm at start time of car speed limit release at restart time of car speed limit and a means i controlling a display lamp in the operating room so as to be lighted during car speed limit also to be actuated by a first on/off pattern during a car speed limit release to be actuated by a second on/off pattern during engine control returning a car speed to the limit value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a vehicle speed limiting device.

[0002]

2. Description of the Related Art In order to cope with the speeding up of vehicles due to the development of expressways, the output of engines and the number of transmission stages are increasing in commercial vehicles such as trucks. It is also required to reduce operating costs. Therefore, in order to improve the fuel, it is conceivable to limit the maximum engine speed to a low speed.

[0003] As an example, a normal fuel supply amount obtained from the accelerator opening and the engine speed and a vehicle speed limiting fuel supply amount obtained from the vehicle speed are set so that the vehicle speed is suppressed to a predetermined limit value or less. There is one in which the maximum fuel supply rate to the engine is limited by selecting a smaller fuel supply quantity and reducing the fuel supply quantity to the engine (Japanese Patent Laid-Open No. 8-151946).

Although it is not intended to improve fuel efficiency, the engine speed is controlled so as not to exceed the set speed for each gear of the transmission in order to achieve both vehicle speed limitation and power band. An example is also known (Japanese Utility Model Publication No. 6-49862).

[0005]

However, although the vehicle speed limitation (which limits the maximum engine speed by reducing the fuel supply amount) contributes to improvement in fuel efficiency, even if the accelerator pedal is fully depressed, Since the vehicle speed is limited to a predetermined value or less, the usability is not good for overtaking. When traveling uphill, the vehicle speed is greatly reduced due to the transmission shifting operation, so the vehicle speed is usually set on a flat road.However, if the vehicle speed limit value is not increased, the engine speed after shifting becomes too low. The driving force was lacking,
There was also a possibility that the vehicle would stop.

The present invention is intended to solve such a problem by providing means for canceling the vehicle speed limitation.

[0007]

In the first invention, FIG.
In a vehicle speed limiting device including means a for limiting the maximum speed of engine rotation by reducing the fuel supply amount of the engine so as to suppress the vehicle speed to a predetermined limit value or less,
When a specific switch is turned on, a means c for releasing the above-mentioned vehicle speed limitation is provided.

In the second invention, as shown in FIG. 12, a vehicle speed limiting device having means a for limiting the maximum engine speed by reducing the amount of fuel supplied to the engine so as to keep the vehicle speed below a predetermined limit value. , A means d for determining that an accelerator operation in a predetermined pattern has been performed and a means c for releasing the vehicle speed limit for a predetermined time at the time of the determination are provided.

According to a third aspect of the present invention, as shown in FIG. 12, the vehicle speed limiting device includes means a for limiting the maximum engine speed by reducing the amount of fuel supplied to the engine so as to keep the vehicle speed below a predetermined limit value. A means e for determining that a shift operation of the transmission has been performed, and a means c for releasing the vehicle speed limitation for a predetermined time at the time of the determination.
Is provided.

According to a fourth aspect of the present invention, as shown in FIG. 12, a vehicle speed limiting device including means a for limiting the maximum engine speed by reducing the amount of fuel supplied to the engine so as to keep the vehicle speed below a predetermined limit value. In the above, there are provided means f for judging that the vehicle is in the uphill state based on the running acceleration of the vehicle and the accelerator opening of the engine, and means c for releasing the vehicle speed limitation for a predetermined time when the judgment is made.

According to a fifth aspect of the present invention, in any one of the second to fourth aspects of the present invention, when the vehicle speed limitation release time elapses as shown in FIG. 12, the vehicle speed at that time is limited by a predetermined deceleration. Means g for performing engine control to return the value to a value is provided.

According to a sixth aspect of the present invention, in any one of the first to fourth aspects of the present invention, an alarm is issued at least one of when vehicle speed limitation is released and vehicle speed limitation is resumed as shown in FIG. Means h for controlling the buzzer in the cab is provided.

According to a seventh aspect of the present invention, in any one of the first to fourth aspects of the present invention, there is provided means i for controlling a display lamp in a driver's cab so as to be turned on during vehicle speed limitation as shown in FIG. .

According to an eighth aspect of the present invention, in the fifth aspect, the engine control is turned on during the vehicle speed limitation as shown in FIG. 12, and operates in the first blinking pattern while the vehicle speed limitation is released to return the vehicle speed to the limit value. Means i for controlling the indicator lamps in the operator's cab is provided so as to operate in the second blinking pattern.

[0015]

According to the first aspect of the present invention, when a specific switch is turned on, the vehicle speed limit is released, and the engine performance can be maximized. When the specific switch is turned off, the vehicle returns to the running state in which the vehicle speed limitation is applied. That is, the driver can arbitrarily select the vehicle speed restriction and its release.

In the second aspect, when acceleration of the vehicle is required, if the driver performs an accelerator operation according to a predetermined pattern, the vehicle speed restriction is released for a predetermined time.

According to the third aspect, when the shift operation of the vehicle is performed, the vehicle speed restriction is released for a predetermined time by the determination (when the vehicle needs to be accelerated).

In the fourth aspect, when the vehicle shifts to the uphill traveling, the state (when the vehicle needs to be accelerated) is determined, and the vehicle speed restriction is released for a predetermined time.

In the first to fourth inventions, when the vehicle speed is released during the vehicle speed limitation, the fuel supply amount increases in accordance with the accelerator opening, so that the engine speed increases and the vehicle speed exceeds the limit value. Can be increased. As a result, the overtaking performance of the vehicle is improved, and the engine speed can be increased (that is, the engine speed is maintained at a high speed) before the decrease in the engine speed becomes large when shifting to the uphill traveling. Vehicle speed and driving force can be secured.

In the second to fourth inventions, the vehicle speed limit is automatically restarted after a predetermined release time has elapsed. Therefore, when the fuel supply amount is reduced at a stretch when returning to the vehicle speed limit, the vehicle speed limit is reduced. Although there is a possibility of giving a shock to the running state, in the fifth invention, the vehicle speed is gradually returned to the limit value according to the predetermined deceleration, so that it is possible to prevent the occurrence of a shock due to the return to the limit vehicle speed. it can.

In the sixth aspect, the driver can easily recognize the start of the vehicle speed limit release and the restart of the vehicle speed limit by the alarm buzzer.

According to the seventh aspect, the driver can easily confirm whether or not the vehicle speed is being restricted by the display lamp in the driver's cab.

According to the eighth aspect of the present invention, not only whether the vehicle speed is being restricted but also whether the vehicle is being restricted or returning to the limited vehicle speed can be easily determined by the difference in the blinking pattern. Can be confirmed.

[0024]

1 is a diesel engine, 2 is a clutch, 3 is a transmission, and an output shaft of the transmission 3 is connected to a rear axle via a propeller shaft (not shown). The engine fuel injection pump is provided with a governor device 1A for controlling the fuel injection amount, the clutch 2 is provided with a clutch booster 2A for performing the on-off operation, and the transmission 3 is provided with a gear shift unit 3A for driving the gear shift mechanism. Reference numeral 27 denotes a supply / discharge valve of the clutch booster 2A.

As detection means necessary for vehicle shift control,
Engine rotation sensor 29 for detecting engine rotation speed
, An accelerator opening sensor 28 for detecting an amount of depression of an accelerator pedal 7 (accelerator opening), a clutch stroke sensor 22 for detecting a stroke position of the clutch 2, and a gear position sensor (a gear shift) for detecting a shift position of the transmission 3. (Built into unit 3A)
And a vehicle speed sensor 21 for detecting the rotation speed of the output shaft.
And a gear rotation sensor 23 that detects the rotation speed of the main gear that idles on the main shaft.

Manual control of clutch 2 (manual operation)
And automatic control, clutch switches 24 and 25 for detecting an initial position and an operating position of the clutch pedal are provided. A shift lever unit 4 is provided in the cab as a shift operation means of the transmission 2, and outputs a range signal of the shift lever 4A. Shift lever 4
The driving state of the vehicle (vehicle speed and accelerator opening) is shown in the knob of A.
A switch 5 is provided for arbitrarily switching between an automatic shift mode in which a shift change is automatically performed to an optimal shift speed corresponding to the shift speed and a manual shift mode in which a shift change is performed to a selected speed of the shift lever 4A.

The driver's cab is provided with a monitor 13 equipped with a transmission position display lamp and the like, and a brake pedal switch 26 for detecting depression of a brake pedal (not shown). A lamp 42 for displaying restriction release or the like is added. In addition, a buzzer 13A for alarming release and restart of the vehicle speed limitation is arranged in the driver's cab.

An engine control unit 11 and a transmission control unit 12 control the vehicle speed change operation, vehicle speed limitation and release based on these output signals, and serial communication (LAN) is performed between these control units 11 and 12. Are tied together. Regarding a shift operation of the vehicle, when a shift request based on a lever operation of the shift lever unit 4 or a shift request based on a running state of the vehicle is generated, a series of shift operations is controlled to shift gears to the requested position. That is, the clutch 2
, And if the transmission 3 is not in neutral, the gear is removed. When the main gear rotation speed enters the synchronization region while controlling the engine rotation speed as necessary, the transmission 3 is engaged.

FIG. 2 is a block diagram of a control system relating to vehicle speed limitation. The transmission control unit 11 includes a storage means 43 for storing a vehicle speed limit value for each speed stage of the transmission 3. A vehicle speed limit value input means 41 for externally rewriting these stored values is provided in the cab. The detection signal of the vehicle speed sensor 21, the detection signal of the gear position sensor 44, the detection signal of the accelerator opening sensor 28, and the shift lever device 4
Transmission 3 based on the range position signal of
Storage means 4 stores the vehicle speed limit value Vb for a specific gear
3 and instructs the engine control unit 12 to reduce the fuel injection amount of the engine during the vehicle speed limit so that the vehicle speed does not normally exceed the limit value.

If at least one of the following conditions is satisfied during the vehicle speed limit: a gear change operation, a shift to a vehicle running uphill, or a predetermined pattern of accelerator operation, the vehicle speed limit value is reduced to a limit release value. Is instructed to perform normal engine control for a predetermined time. When the predetermined time has elapsed, the vehicle speed limitation is restarted. At this time, if the fuel supply of the engine is reduced at a stretch, a shock occurs in the running state of the vehicle, and the vehicle speed is limited according to a predetermined deceleration (set in the memory). Control unit 12 so as to gradually reduce the vehicle speed to the vehicle speed limit value.
The vehicle speed limit command value is controlled.

When a vehicle speed limit command is received from the transmission control unit 11, the engine control unit 12 reduces the engine fuel injection amount by the engine speed control means 45 based on the detection signal of the engine speed sensor 29, thereby limiting the vehicle speed limit. Is controlled so as not to exceed the engine speed corresponding to. When a command to release the vehicle speed restriction is received, the control is switched to normal engine control, and the fuel injection amount of the engine is controlled so that the engine rotation speed according to the detection signal of the accelerator opening sensor 28 is obtained. When the vehicle speed limit is resumed, the vehicle speed limit command value from the transmission control unit 11 decreases with time at a predetermined deceleration, so that the fuel injection amount of the engine is gradually reduced so that the vehicle speed gradually decreases according to the change. Control to squeeze.

The transmission control unit 11 activates an alarm buzzer 13A in the driver's cab when the vehicle speed limit is released and when the vehicle speed limit is restarted. Monitor 1
The display lamp 42 of No. 3 is turned on while the vehicle speed is being restricted, and operates with a short interval flashing pattern while the restriction is being released.
During the control to gradually return the vehicle speed, a function to control the lamp display is provided so that the operation is performed in a long-interval blinking pattern. Note that when the shift lever 4A is switched to the manual shift mode using the automatic shift mode / manual shift mode switching switch 5, the vehicle speed limitation may be released during that time. Of course, a dedicated switch for releasing the vehicle speed limitation may be provided.

Referring to FIG. 3, an example of a change in the vehicle speed limitation and the running state of the vehicle accompanying the release and resumption will be described. When the above-described predetermined condition is satisfied during the vehicle speed limitation, the vehicle speed limitation is released. Since the fuel injection amount of the engine increases in accordance with the accelerator opening, the engine rotation speed increases. The vehicle speed V also increases beyond the vehicle speed limit value Vb. As a result, the overtaking performance of the vehicle is improved, and when shifting to uphill running, the engine speed can be increased before the decrease in engine speed becomes large, so that the vehicle speed and driving force after shifting can be secured. Become.

After the release time CK has elapsed, engine control is performed to gradually return the vehicle speed from V0 to the limit value Vb at a predetermined deceleration α. When the vehicle speed V reaches the limit value Vb, the vehicle speed limit command value Vs becomes Vb, and the vehicle speed limit is restarted.
When the vehicle speed V decreases from the limit value Vb, normal engine control according to the accelerator opening is performed. Therefore, when there is enough driving force, when the accelerator pedal is depressed, the vehicle speed V increases and the vehicle speed limitation is restarted. Will be done.

The indicator lamp 42 in the driver's cab lights up while the vehicle speed is being limited, and has a short interval blinking pattern 1 when the limitation is being released.
During the control for returning the vehicle speed V from V0 to the limit value Vb, the operation is performed in the blinking pattern 2 having a long interval. The warning buzzer 13A in the driver's cab is activated when the vehicle speed limit is released and restarted (when control for returning the vehicle speed V to the limit value Vb is started).

FIGS. 4 and 5 are flowcharts for explaining the control contents relating to the vehicle speed limitation, which is performed by the transmission control unit 11.

In FIG. 4, at step 1, the gear position (gear position) of the transmission 3 is detected, and at step 2, it is determined whether the detected gear position is a specific gear position. If yes, go to step 3; if no, go to step 18. In step 3, the vehicle speed limit release flag FS = 1
It is determined whether or not the answer is yes. In step 4, the command value Vs for limiting the vehicle speed to the engine control unit 12
Is set as the vehicle speed release value Va. If no, the vehicle speed limit value Vb corresponding to the gear is set as Vs in step S5.

In step 6, it is determined whether or not the release time measurement start flag FK is 1. If yes, in step 7, the release time counter CT is operated (CT + 1 → CT). If no, at step 8 the measurement start flag FK
To 1. In step 9, the release time counter CT
To 0.

In step 10, it is determined whether or not the release time counter CT has reached a predetermined time CK. If yes, the measurement start flag FK is set to 0 in step 11. At the same time, the timer t is counted up in step 12 (t + 1
→ t). If no, the vehicle speed value V0 (current vehicle speed) in the memory is rewritten in step 13 using the detected value V of the vehicle speed as the latest data, and the timer t is set to 0 in step 14.

In step 15, it is determined whether or not the detected value V of the vehicle speed has reached the vehicle speed limit value Vb.
In step 16, a vehicle speed limit value Vb is set as a command value Vs to the engine control unit 12. If the answer is no, the release time counter CT sets the predetermined time C in step 17.
From the vehicle speed value V0 at the time when the elapsed time of K is counted up, the predetermined deceleration α, and the measurement time of the timer t, V0−α × t
Is set as a command value Vs to the engine control unit. That is, V0−α × t is set as Vs until the detected value V of the vehicle speed reaches the vehicle speed limit value. In step 18, the engine control unit 1
To 2, the command value Vs of the vehicle speed limit and the release flag FS of the vehicle speed limit
To communicate.

In FIG. 5, the vehicle speed limit release flag F
In order to control S, it is determined in step 1 whether or not the detected value V of the vehicle speed is equal to or greater than a value (Vb-β) obtained by subtracting a predetermined value β from the vehicle speed limit value Vb.
In the case of "o", the process proceeds to step 7, and the vehicle speed limit release flag FS is set to "0". In step 2, it is determined whether a shift operation of the vehicle has been performed, and in step 3, it is determined whether the vehicle is traveling uphill. In step 4, the accelerator operation pattern P1 is detected, and in step 5, it is determined whether the detected pattern P1 is within a predetermined accelerator operation pattern P0. In steps 2, 3 and 5, when at least one of these determinations is "yes", the vehicle speed limit release flag FS is set to 1 in step 6, while when all determinations are "no", the release flag is determined in step 7 Set FS to 0.

FIG. 6 is a flowchart for explaining the determination processing during the uphill traveling performed in step 3 of FIG.
In step 1, the accelerator opening is detected. In step 2, it is determined whether or not the detected value is equal to or more than a predetermined value (for example, 90%). If yes, the process proceeds to step 3, and if no, the process proceeds to step 9. In step 3, the vehicle speed V is detected, and in step 4, the acceleration a is calculated from the detected value V of the vehicle speed. In step 6, the acceleration a is set to a predetermined value (for example, -1.
5 km / h / sec) or less. If yes, proceed to step 6; if no, proceed to step 9.

When the accelerator opening degree is 90% or more and the acceleration a of the vehicle enters a running state of -1.5 km / h / sec or less (shaded area in FIG. 7), the counting of the timer t is started in step 6. . In step 7, it is determined whether the counter t has reached a predetermined time (for example, 0.5 sec). That is, in step 7, it is determined whether or not the uphill traveling in the shaded area of FIG. 7 continues for a predetermined time t. If yes, it is determined in step 8 that the uphill traveling is in progress.
If no, it is determined in step 10 that the vehicle is not traveling uphill. If at least one of steps 2 and 5 is no, the counter t is cleared in step 9. Thereafter, the process proceeds to step 10.

The accelerator operation pattern determined in step 5 of FIG. 5 will be described with reference to FIG. Accel full A, C, E flags and accelerator off B, D described later
Areas (each shaded area) A to E where the flag is set to 1 are set. Return the accelerator pedal 7 from the depressed state once,
When the accelerator pedal travels through the regions A to E in order as indicated by the solid lines by further depressing the accelerator pedal twice, the accelerator full A, C, E flags and the accelerator off B, D flags all become 1, and the predetermined pattern is obtained. It is determined that the accelerator operation within P0 has been performed, and it is determined that the other accelerator operation pattern P1 is not within the predetermined pattern P0.

The determination process of the accelerator operation pattern including the detection process performed in step 4 of FIG. 5 will be described with reference to the flowcharts of FIGS. In step 1, the accelerator opening is detected. In step 2, accelerator full A
It is determined whether the flag is 1. If yes, the counter of the timer t is started in step 3. Then, it is determined in step 4 whether the accelerator off B flag is 1, in step 5 the accelerator full C flag is 1, and in step 6, whether the accelerator off D flag is 1 or not. Proceed to.

If the determination in step 2 is no, the process proceeds to step 11 and determines whether or not the detected value of the accelerator opening is equal to or more than a predetermined value (for example, 80%). If yes, the accelerator full A flag is set to 1 at step and the counter of the timer t is cleared at step 13. If the determination in step 11 is no, the process proceeds to step 14, where the accelerator full A, C, E flags and accelerator off B, D
Set all flags to 0.

If the determination in step 4 is no, the process proceeds to step 15. In steps 15 to 17, the counter of the timer t is set to a predetermined time range (t = 0.2
０．６0.6 sec), the detected value of the accelerator opening is 20
If it is determined to be less than%, the accelerator off B flag is set to 1. If the determination in step 16 is no, step 18
And the accelerator full A, C and E flags and the accelerator off B and D flags are all set to 0.

If the determination in step 5 is no, the process proceeds to step 19. In steps 19 to 21, the counter of the timer t is set to a predetermined time range (t = 0.5
When the detected value of the accelerator opening is 80
If it is determined that the value is not less than%, the accelerator full C flag is set to 1. If the determination in step 20 is no, step 22
And the accelerator full A, C and E flags and the accelerator off B and D flags are all set to 0.

If the determination in step 6 is no, the process proceeds to step 23. In steps 23 to 25, the counter of the timer t is set to a predetermined time range (t = 0.8
１．２1.2 sec), the detected value of the accelerator opening is 20
%, The accelerator off D flag is set to 1. If the determination in step 24 is no, step 26
And the accelerator full A, C and E flags and the accelerator off B and D flags are all set to 0.

When the determination in step 6 is yes, in steps 7 to 9, when the counter of the timer t is within a predetermined time range (t = 0.8 to 1.2 sec), the detected value of the accelerator opening is 80 If it is determined to be equal to or greater than%, the accelerator full E flag is set to 1 in step 9 As a result, it is determined in step 10 that the accelerator operation pattern P1 is within the predetermined pattern P0. If the determination in step 24 is no, the process proceeds to step 26, where accelerator full A, C,
The E flag and the accelerator off B, D flags are all set to 0.

If any one of Step 2, Step 4, Step 5, and Step 6 is no, in Step 28, it is determined that the accelerator operation pattern P1 is not within the predetermined pattern P0.

FIG. 11 is a flow chart for explaining the control contents of the alarm buzzer 13A and the display lamp 42 in the cab. FIG. 3 shows a time chart. In step 1, it is determined whether or not the designated value Vs of the vehicle speed limit is the limit release value Va. If yes, the step alarm buzzer 13A is operated for a predetermined time (T1 sec). Step 3
To change the display lamp 42 to the blinking pattern 1 with a short interval.
Operate with

If the determination in step 1 is no, the process proceeds to step 4. In step 4, the vehicle speed limit command value Vs
Is determined to be the limit value Vb. When the determination is no, the control proceeds to step 7 under the control of gradually returning the vehicle speed to the vehicle speed limit value Vb, and the alarm buzzer 13A is set to the predetermined time (T
Operate only for 2 sec). In step 8, the display lamp 42 is operated in a long interval blinking pattern.

If the determination in step 4 is yes, the process proceeds to step 5, where it is determined whether the detected vehicle speed V is equal to or greater than a value (Vb-β) obtained by subtracting a predetermined value β from the vehicle speed limit value Vb. Turns on the display lamp 42 indicating that the vehicle speed is being limited.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram showing an embodiment of the present invention.

FIG. 2 is a block diagram of a control system related to vehicle speed limitation.

FIG. 3 is an explanatory diagram showing a change in a traveling state of the vehicle.

FIG. 4 is a flowchart for explaining control content related to vehicle speed limitation.

FIG. 5 is a flowchart for explaining control contents related to vehicle speed limitation.

FIG. 6 is a flowchart for explaining control content related to vehicle speed limitation.

FIG. 7 is an explanatory diagram showing a determination area for climbing a hill.

FIG. 8 is an explanatory diagram showing a predetermined pattern of an accelerator operation.

FIG. 9 is a flowchart for explaining control contents related to vehicle speed limitation.

FIG. 10 is a flowchart for explaining the control content related to vehicle speed limitation.

FIG. 11 is a flowchart for explaining control content related to vehicle speed limitation.

FIG. 12 is a diagram corresponding to claims of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1A Governor device of fuel injection pump 2A Clutch booster 3A Gear shift unit 4 Shift lever device 5 Switch for switching between automatic shift mode / manual shift mode 11 Transmission control unit 12 Engine control unit 13A Alarm buzzer 21 Vehicle speed sensor 28 Accelerator opening sensor 29 Engine rotation Sensor 41 Vehicle speed limit value input means 42 Vehicle speed limit display lamp 43 Vehicle speed limit value storage means 44 Gear position sensor 45 Engine control means

Claims (8)

[Claims] In a vehicle speed limiting device provided with means for limiting the maximum speed of engine rotation by reducing the amount of fuel supplied to an engine so as to suppress the vehicle speed to a predetermined limit value or less, when a specific switch is turned on, a period between the turning on and off is limited. A vehicle speed limiting device comprising means for releasing the vehicle speed limit. 2. A vehicle speed limiting device comprising means for limiting the maximum speed of engine rotation by reducing the amount of fuel supplied to the engine so as to keep the vehicle speed at or below a predetermined limit value. A means for determining that the vehicle speed has been limited, and means for releasing the vehicle speed limitation for a predetermined time at the time of the determination. 3. A speed change operation of a transmission is performed in a vehicle speed limiting device including means for limiting a maximum engine speed by reducing a fuel supply amount of an engine so as to suppress a vehicle speed to a predetermined limit value or less. And a means for canceling the vehicle speed limitation for a predetermined time at the time of the determination. 4. A vehicle speed limiting device comprising means for limiting the maximum speed of engine rotation by reducing the amount of fuel supplied to the engine so as to keep the vehicle speed below a predetermined limit value. A vehicle speed limiting device comprising: means for determining that the vehicle is climbing a slope based on the opening degree; and means for releasing the vehicle speed limitation for a predetermined time at the time of the determination. 5. The method according to claim 2, further comprising: means for performing engine control for returning the vehicle speed to a limit value at a predetermined deceleration when the vehicle speed restriction release time has elapsed. The vehicle speed limiting device according to one of the preceding claims. 6. A driver's cab buzzer is controlled so as to issue an alarm at least one of when vehicle speed limitation is released and when vehicle speed limitation is resumed.
The vehicle speed limiting device according to claim 4. 7. The vehicle speed limiting device according to claim 1, further comprising means for controlling a display lamp in a driver's cab so as to light up when the vehicle speed is limited. 8. The driver's cabin is illuminated so as to light up during the vehicle speed limit, operate in the first blinking pattern when the vehicle speed limit is released, and operate in the second blinking pattern during engine control for returning the vehicle speed to the limit value. The vehicle speed limiting device according to claim 5, further comprising means for controlling the display lamp.