WO1997013651A1

WO1997013651A1 - Vehicle speed-regulating arrangement

Info

Publication number: WO1997013651A1
Application number: PCT/EP1996/004286
Authority: WO
Inventors: Karl-Fritz Heinzelmann; Hubert Heller
Original assignee: Zf Friedrichshafen Ag
Priority date: 1995-10-06
Filing date: 1996-10-01
Publication date: 1997-04-17
Also published as: DE19537273A1

Abstract

The invention concerns an arrangement for regulating the speed of motor vehicles with an internal combustion engine and additional braking systems. An operating element (2) of the speed-regulating arrangement has switching positions (4, 6, 8, 20, 22, 24, 42, 44, 52, 54, 56) for influencing the engine control braking stages and switching positions (10, 12, 14, 16, 17, 26, 28, 30, 31, 32, 58, 60, 62, 64, 66) for influencing the braking system braking stages. The first and second switching positions can be in a single switching plane (18). A second switching plane (40), which is perpendicular to the first switching plane (18) and comprises speed-regulation switching positions (42, 44), can additionally be provided. Retarders, engine brakes, exhaust flap brakes or the gear control system in an automatic transmission can serve as braking devices.

Description

Vehicle speed control device

The invention relates to a device for speed control of vehicles according to the preamble of claim 1.

In modern vehicles, a large number of operating elements are provided which are to be operated by the driver and which require a corresponding amount of attention from the driver when operating. Various types of vehicles today have devices with which the speed of the vehicle can be preselected or adjusted and then kept constant by the automatic control at the preselected value. These devices are also known under the term "cruise control". It is known from ATZ Automotivtechnische Zeitschrift 95 (1993) 2, pages 80 to 88, "Electronic Accelerator Pedal for Commercial Vehicles" that, after activation of a speed control device, the current speed of the vehicle is automatically controlled via the control lever. The driver can take his foot off the accelerator pedal and devote his full attention to the traffic. This represents a noticeable relief for the driver, particularly on long freeway journeys or compliance with speed limits. The regulated speed can be passed over for short overtaking maneuvers. After falling back to the set speed, the speed control is automatically resumed. To fine-tune the speed, for example when driving in a column, the setpoint can be increased or decreased in small steps. From this magazine it is also known to use the speed control to control wear-free additional deceleration devices, such as, for example, retarders. Retarders and also motor brakes can be used to keep the vehicle speed constant on a downhill gradient where there is an intervention in the motor control alone may not be sufficient to maintain a low speed.

In addition to the service brakes of a vehicle, in particular a commercial vehicle, which are generally friction brakes that are subject to wear, additional deceleration devices such as retarders are also increasingly being required by law and offered by vehicle manufacturers.

In addition to the retarders, hydrodynamic, hydrostatic or electrodynamic braking devices arranged on the transmission or motor are understood as well as those systems which are provided within the transmission housing.

Retarders are further differentiated into primary retarders that work depending on the engine speed and secondary retarders that work depending on the vehicle speed.

There are different types of actuation of the retarder. The braking effect can be controlled in steps or continuously within the maximum performance of the retarder.

First of all, the actuation by a brake stage switch, usually in the form of a steering column lever or a switch, which in the immediate vicinity of the steering wheel the driver is conveniently located, several braking levels.

A brake level switch is also used in conjunction with a step plate, which can be operated by the driver in the footwell primarily in combination with the service brakes as a brake pedal with the foot.

The retarder is used to different extents in the different braking stages. In known systems, the desired braking effect is set via the brake level switch and the instantaneous speed achieved can be stored by actuating an additional switch, for example a button on the brake level switch. The stored speed is maintained and the brake level switch is returned to "0", the neutral position. To delete the stored speed, the additional switch is actuated again in any changed position of the brake step switch.

EP 0 336 913 A1 discloses a method and an arrangement in which the speed of a vehicle can be kept constant downhill. Here, the driver activates the brake, for example via the brake pedal. The lowest speed that the vehicle reaches during the braking process is saved as a target value in a control unit. The retarder as well as the service brake and exhaust brake are controlled via the brake pedal. The harder the brake pedal is pressed, the stronger the braking effect of the retarder is activated. The service brake is activated as of a predetermined brake pedal actuation. If the target value is reached, the brake pedal can be released. A speed control system controls the retarder and exhaust brake. The current speed is approximated to the target speed by activating all brakes. When the driver releases the brake pedal, the retarder and exhaust brake automatically keep the speed until the vehicle accelerates again.

The auxiliary brakes can also be activated with a five-stage shift lever. A button on this gear lever activates the speed control.

The known systems still have serious disadvantages in various situations.

For example, in vehicles which are equipped with a cruise control for train operation, the speed for train operation (engine control) and brake operation (retarder control) is set with two different operating elements.

This system separation is complex for the driver and can lead to incorrect operation. If, for example, the programmed braking speed is below the programmed train speed, this can lead to the two systems working against each other.

From DE 43 20 111 AI it is known to provide the driving speed control or the limitation of the driving speed only by means of a pushbutton or switching element for the setpoint specification. In this case, both systems are locked against one another, so that working against one another can be switched off. With this arrangement, it is not possible to specify a desired braking power in the form of predetermined braking levels, as the user of retarder controls is used to today. From experience, the driver knows what braking power he needs for a particular one Desires to go down a slope so that it can be descended as quickly, economically and stress-free as possible.

It is the object of the invention, based on this prior art, to propose an operating device which represents a possible combination of a brake step switch for a step-by-step braking power with a constant-speed device.

The object is achieved by an operating element according to claim 1. Refinements are the subject of subclaims.

The invention is explained in more detail with reference to figures. Show it:

1 shows an operating element in a first embodiment;

Fig. 2 shows a modified arrangement according to Fig. 1 and

3 shows a modified arrangement according to FIG. 1 or FIG. 2.

The step switches provided in vehicles with retarder controls are often arranged in the form of steering column levers on or near the steering column, while the levers for influencing the motor control to keep the speed constant are also provided as additional steering column levers.

1 shows on a dashboard 3 a steering wheel 1 with a steering column lever 2 which, in the embodiment shown here, can assume eight different positions. The different positions are provided with the reference numerals 4, 6, 8, 10, 12, 14, 16 and 17. All positions are in a switching plane 18, so that the driver does not make movements of the steering column lever 2 back and forth in the direction of travel, but only has to move the lever 2 up or down. Position 6 represents a center position or neutral position sprung in both directions. From this neutral position 6, the steering column lever 2 can be switched to a first position 4, in which the engine control of the vehicle is controlled in such a way that the speed of the vehicle increases. Steering column lever 2 does not engage in position 4, but the speed is increased as long as the driver holds steering column lever 2 in position 4. The increase in speed takes place according to a given ramp function, the speed increasing for example by 1 km / h per 1 second of stopping time. If the driver releases the lever 2 when the desired speed is reached, the lever 2 returns to the neutral position 6. The speed reached is stored when the steering column lever reaches neutral position 6. With the speed control switched on, the current speed is stored or held when the steering column lever 2 is in the neutral position or center position 6. To set a first target speed to be kept at least provisionally, it can be provided that only the overall speed control has to be switched on without the target speed having to be set additionally via a further special switch position. The speed control can therefore be switched on, the current vehicle speed being simultaneously stored as the desired speed. The setpoint is saved using a special A memory button with activated cruise control is of course also possible.

To reduce the speed of the vehicle, the driver can correspondingly move the steering column lever 2 from the neutral position 6 into a second position 8. As long as the lever 2 is held in this position 8 by the driver, the engine control of the vehicle is controlled in such a way that the speed of the vehicle lowers. The decrease in speed preferably takes place according to a predetermined ramp function, with the speed decreasing, for example, by 1 km / h per 1 second of holding time. If the driver releases lever 2 when the desired speed is reached, this returns to neutral position 6.

If the influencing of the motor control is not sufficient to reduce the speed, the brake control is activated. For this purpose, the steering column lever 2 in its shift gate can be moved into positions 10, 12, 14, 16 or 17 via a resistor between positions 8 and 10, which correspond to the respective braking stages. The five stages shown here serve as examples for any number of braking stages, which, depending on the type and arrangement of braking devices, can be provided in the vehicle. Retarders, engine brakes, exhaust flap brakes and also the transmission control in an automatically shifted transmission can be controlled in stages as braking devices. The further the steering column lever 2 is moved downward, the higher the braking level that is activated. The braking stages can either form a constant braking torque increasing from stage to stage or a constant deceleration increasing from stage to stage. the vehicle. The greatest possible delay is reached in position 17. The braking device is preferably formed by a retarder with a number of braking stages which are controlled by the position of the steering column lever. Motor control and retarder control do not influence each other negatively, whereby a superimposition of the two areas is quite possible to achieve a desired speed. A switch 19, which is arranged at the upper end of the steering column lever 2, is used, for example, to activate the speed control. One tap here means "switch on", the next tap of the switch 19 means "switch off", the next tap again "switch on".

FIG. 2 shows a modification of the arrangement according to FIG. 1. A steering column lever 2 is also provided on a steering wheel 1, which has different switching positions 20, 22, 24, 26, 28, 30, 31, 32. All positions are in a switching plane 34, so that the driver does not move the steering column lever 2 forward and back in here

Carries direction of travel, but only has to move the lever 2 up or down. Position 22 in turn represents a neutral position sprung in both directions. From this neutral position 22 the steering column arm 2 can be switched to a first position 20 in which the speed control of the vehicle is controlled in such a way that the speed of the Vehicle increased. Here, too, the speed is generally controlled by intervening in the engine control and subsequently increasing the engine output. On a downhill slope, however, the speed can also be increased by reducing or switching off the braking action of the controlled braking devices. The steering column lever 2 does not engage in position 20, but the speed is increased as long as the driver holds the steering column lever 2 in this position 20. The increase in speed preferably takes place according to a predetermined ramp function, the speed increasing, for example, by 1 km / h per 1 second of holding time. If the steering column lever 2 is only briefly tapped into the position, the speed increases by a predetermined amount, for example by 1 km / h. Multiple tapping leads to a corresponding increase in speed by a multiple of the predetermined amount, that is to say by n * 1 km / h, where n represents the number of taps of lever 2. If the driver releases the lever 2 when the desired speed is reached, the lever 2 returns to the neutral position 22. The speed reached is stored when the steering column lever 2 reaches the neutral position 22. When the speed control is switched on, the current speed is stored or held when the steering column lever 2 is in the neutral position or center position 22. To set a first target speed, which is to be kept at least provisionally, it can in turn be provided that only the overall speed control is switched on, without the target speed having to be set specifically via a special switch position. The speed control can thus be switched on, with the current vehicle speed being stored at the same time as the desired speed. It is of course also possible to store the setpoint using a special memory key when the cruise control is activated. To reduce the speed of the vehicle, the driver can correspondingly move the steering column lever 2 from the neutral position 22 into a second position 24. As long as the lever 2 is held in this position 24 by the driver, the speed control of the vehicle is controlled in such a way that the speed of the vehicle lowers. Here, too, the speed is generally controlled by intervening in the engine control and subsequently reducing the engine power. On a downhill slope, however, the speed can also be reduced by using or increasing the braking effect of the controlled braking devices.

The pitman arm 2 does not engage in position 24, but the speed is reduced as long as the driver holds the pitman arm 2 in this position 24. The decrease in speed preferably takes place according to a predetermined ramp function, the speed decreasing, for example, by 1 km / h per 1 second of holding time. If the steering column lever 2 is only briefly tapped into the position 24, the speed decreases by a predetermined amount, for example by 1 km / h. Multiple taps lead to a corresponding speed reduction by a multiple of the predetermined amount, ie by n * 1 km / h, where n represents the number of taps of the lever 2. If the driver releases the lever 2 when the desired speed is reached, the lever 2 returns to the neutral position 22. Other amounts of the speed change, such as 0.5 km / h or 2 km / h or more, are also possible.

If the reduction in speed via the ramp function is not sufficient, the braking levels of the provided braking devices, in particular the predetermined braking levels of the retarder control, activated, whereby the speed is further reduced. For this purpose, the steering column lever 2 can be brought into positions 26, 28, 30, 31, 32 in its shifting lane over a resistance between positions 24 and 26, which correspond to the respective braking stages. The five stages shown here serve as examples for any number of brake stages, which, depending on the type of retarder or the brake devices, can be provided. The further the steering column lever 2 is moved downward, the higher the braking level that is activated. The braking stages can either form a constant braking torque increasing from stage to stage or a constant deceleration of the vehicle increasing from stage to stage. The greatest possible deceleration is achieved in position 32. Motor control and retarder control do not negatively influence one another, whereby a superimposition of the two areas to achieve a desired speed is quite possible. A switch 36, which is arranged at the upper end of the steering column lever 2, is used to activate the speed control. One tap here means "switch on", the next tap of switch 36 means "switch off", the next tap again "switch on".

FIG. 3 shows an expanded arrangement according to FIG. 1 or FIG. 2. Likewise, a steering column lever 2 is provided on a steering wheel 1, which has different switching positions 52, 54, 56, 58, 60, 62, 64, 66 . All positions are in a switching plane 50. Position 54 in turn represents a neutral position that is sprung in both directions. right to the switching level 50, a second switching level 40 is provided. The intersection of the two planes lies in the sprung neutral position 54 of the steering column lever 2. The second switching plane 40 has three positions, a first position as a neutral position 54, a second position 42 as a first end position of the steering column lever 2 in one direction in the switching plane 40 and a third position 44 as the second end position of the steering column lever 2 in the other direction in the switching plane 40. The end position 42 is preferably in the rear in the direction of travel and the end position 44 in the direction of travel in the front. The steering column lever 2 does not engage in the end positions 42 and 44, but a signal is generated when the end position is reached. In the end position 42, for example, the speed control can be activated and in position 44 the speed control can be deactivated. Position 42 can also mean the signal "resumption of stored speed", for example, wherein the steering column lever can preferably be pulled in the direction of the driver to reach position 42. In the latter case, the speed control can be activated by a switch 46 in the steering column lever 2.

The speed reached is stored when the steering column lever reaches the neutral position 54. With the cruise control switched on, the

Steering column lever 2 in neutral or middle position 54 the current speed saved and held. In order to set a first target speed to be kept at least provisionally, it can be provided that only the overall speed control is switched on without the target speed having to be set additionally by means of a special switch. Here, too, the steering column lever 2 can be moved from its off position 44 into the switch-on position. tion 42 are brought, with which the cruise control is switched on, or the cruise control is switched on with the aid of the switch 46. After the steering column lever has been returned to the neutral position 54, the vehicle speed currently present is stored as the desired speed.

The data exchange between the control element, engine control, brake control and possibly a connecting control device can take place digitally, via pulse-width-modulated signals or via CAN bus lines.

Reference sign

1 steering wheel

2 steering column levers

3 dashboard

4 switch position

6 neutral position

8 - 16 switching divisions

18 switching level

19 switches

20 switch position

22 neutral position

24 - 32 switching positions

34 switching level

36 switches

40 switching level

42 switching position

44 switching position

46 switches

50 switching level

52 switching division

54 neutral position

56 - 66 switching positions

Claims

Patent claims

1. Device for speed control of a motor vehicle, the functions of which can be controlled via an operating element (2), with an intervention in a motor control and a control, at least one braking device, characterized in that the operating element (2) has first switching positions ( 4, 6, 8, 20, 22, 24, 42, 44, 52, 54, 56) to influence the speed control and second switching positions (10, 12, 14, 16, 17, 26, 28, 30, 31, 32, 58, 60, 62, 64, 66) for switching different braking stages, at least one braking device.

2. Device for speed control of motor vehicles according to claim 1, characterized in that the first switching positions (4, 6, 8, 20, 22, 24, 42, 44, 52, 54, 56) for influencing the speed control such Switch positions are, the signals of which influence the motor control.

3. A device for speed control of motor vehicles according to claim 1, characterized in that the first switch positions (4, 6, 8, 20, 22, 24, 42, 44, 52, 54, 56) for influencing the speed control are such Are switching positions, the signals of which influence the motor control and the least one braking device.

4. A device for speed control of motor vehicles according to one of claims 1 to 3, characterized in that the first switching positions (4, 6, 8, 20, 22, 24, 42, 44, 52, 54, 56) for Influencing the speed control have a neutral position (6, 22, 54), from which the operating element (2) can be moved in directions which are in the same switching level (18) as the second switching positions (10, 12, 14, 16, 17, 26, 28, 30, 31, 32, 58, 60, 62, 64, 66) for controlling the braking stages, at least one braking device.

5. A device for speed control of motor vehicles according to one of claims 1 to 3, characterized in that the first switching positions (4, 6, 8, 20, 22, 24, 42, 44, 52, 54, 56) for Influencing the speed control has a neutral position (54), from which the operating element (2) can be moved in a switching plane (40), which is at an angle to the switching plane (18) for the second switching positions (10, 12, 14, 16, 17, 26, 28, 30, 31, 32, 58, 60, 62, 64, 66) for controlling the braking stages, at least one braking device.

6. Device for speed control of motor vehicles according to one of claims 1 to 5, characterized in that the braking device is a hydrodynamic retarder with several braking stages.

7. Device for speed control of motor vehicles according to one of claims 1 to 5, characterized in that several brake devices are provided.

8. Device for speed control of motor vehicles according to claim 7, characterized in that retarders, engine brakes, exhaust flap brakes and transmission controls of an automatically shifted transmission or combinations thereof are provided as braking devices.

9. Device for speed control of motor vehicles according to one of the preceding claims, characterized in that when the device for speed control is activated and the position of the control element (2) in the neutral position (6, 22, 54) is the actual vehicle speed can be stored as a target vehicle speed.