DE10036257A1 - Transmission system controller for automated or semi-automatic transmissions comprises engine with a starter circuit coupled through the clutch with a clutch with main friction drive clutch and gearbox input shaft - Google Patents

Abstract

The transmission system comprises engine (10) with a starter circuit (10a) coupled through the clutch (14) such as a main friction drive clutch and a gearbox input shaft (15). Fuel is supplied to the engine via throttle (16) operated by a pedal (19). The clutch is actuated via release fork (20) and operated by hydraulic slave cylinder (22) under actuator control means (38). The mechanism and clutch actuation is controlled via an electronic controller (36).

Description

The invention described here relates to automated Power transmission systems for vehicles, and in particular automated manual transmissions or semi-automatic transmissions could, however can also be used for fully automated transmissions. The said Power transmission systems have a main drive clutch, such as Starting clutch and / or clutch, and clutch actuating means for Control of the clutch engagement state, a transmission with several Gear ratios and a gear shift mechanism for shifting the Working gear ratio.

British patent GB 2302377 B discloses an automated one Manual transmission system with means for automatic priority control of a manual transmission ratio, this Priority control takes precedence of a signal over another signal controls or oversteers, as well as with means for switching one more suitable gear ratio for the current Operating conditions when pre-programmed operating conditions occur, while the transmission is in manual mode.

Typical operating conditions where such systems would automatically override the manual gear include:

• 1. exceeding a pre-programmed engine speed; or
• 2. The engine speed drops below a pre-programmed one Minimum value.

Alternatively, an automatic override can be done manually switched gears to be implemented when the Vehicle speed for the currently selected gear a specified exceeds the upper threshold or below a specified lower Threshold drops.

The same applies to fully automated transmission systems Gear shifts carried out in accordance with maps in which the specified maximum and minimum vehicle speed values in every course are saved.

If the vehicle is decelerated in the systems described above, then the conditions may dictate that an automatic Downshifting is required, especially when the driver drives the vehicle want to accelerate again. An automatic downshift under such circumstances would at least result in a delay in response of the vehicle on the accelerator pedal and could result in a result in unexpected forward thrust when the vehicle is in lower gear is accelerated.

In accordance with one aspect of the present invention, a vehicle power transmission system includes a main drive clutch, clutch actuation means for controlling the clutch engagement state, a multi-ratio transmission, a gear shift mechanism for shifting the transmission's gear ratio, and electronic control means for controlling the clutch actuation means and / or the gear shift mechanism. The control means include means for detecting the gear shifted, the speed of an engine, which is connected to the transmission via a clutch, for example, the vehicle speed and the degree of opening of a throttle valve for the engine, the control means being designed such that when the vehicle decelerates

• a) the shifted gear is held while the Vehicle speed is above the pre-programmed Second gear threshold; and
• b) from a currently selected higher gear to second gear is downshifted when the vehicle speed is below the Threshold for second gear drops, taking second gear is held while the vehicle is decelerating and the Vehicle speed below the second gear threshold lies;

the control means causing the clutch actuating means to actuate the Disengage clutch to set engine speed above a pre-programmed Hold minimum value.

In accordance with the invention described herein, a Downshifting from a currently selected higher gear to the second Gear only when the vehicle speed is below the threshold for second gear drops, and consequently the danger is one Downshifting when the driver wants to accelerate very strongly reduced.

In the power transmission system outlined above, this is automatic Downshift prevented from second gear to first gear, the second gear is held until the vehicle comes to a standstill if it is because that manual intervention takes place.  

In accordance with a preferred embodiment of the here described invention, the control means can be an automatic Shift down from second gear to first gear when the Throttle valve opened beyond a pre-programmed threshold while the vehicle speed is below the threshold for second gear, but above a pre-programmed threshold for the first gear and the vehicle continues to run at speed delayed, which is below the threshold for first gear. Such Operating conditions would indicate that the driver is accelerating wants the second gear to be too high, however Gear ratio (too high gear), therefore reduces System gear ratio (gear) to make the vehicle better can be accelerated.

In accordance with another preferred embodiment of the here described invention, the control means can be an automatic Shift down from second gear to first gear when the Brakes are applied and the vehicle speed under one pre-programmed threshold for first gear, whereby indicates that the driver intends to stop the vehicle.

The invention described here is particularly suitable for automated Manual transmission systems or semi-automated transmission systems where downshifting in accordance with the invention described herein would automatically override the manual gearbox if none appropriate intervention is carried out by hand. Under such circumstances Means are provided with the help of which the driver automatically Override could override, if desired by the driver, that of Maintain hand-shifted gear for whatever reason.  

In the case of fully automated transmission systems, the one described above would Downshifting process the more conventional control of the Replace downshift based on maps, which maximum and Minimum vehicle speed values for gear ratios contain.

The following is an exemplary description of embodiments of the invention with reference to the accompanying drawings, wherein:

Figure 1 shows a schematic drawing of an automated power transmission system in accordance with the invention described herein.

Fig. 2 shows a shift pattern for downshifting a conventional automated power transmission system, and

Figure 3 shows a circuit diagram for downshifting an automated transmission system in accordance with the invention described herein.

Automated gears are essentially gears that are made by means of a Actuating unit can be switched both manually and automatically, wherein the selection of the gear can be specified by the driver or by a control unit is predeterminable, the translation then using an actuator (Actuating unit) is adjustable and thus the gear ratio can be changed manually or controlled by an actuator. With semi-automatic The manual translation selection can be initiated by the driver the translation choice is then carried out is carried out by means of an actuator. So the choice of  gear set by the driver and the implementation takes place controlled.

In Fig. 1, a motor 10 is shown with a starter and associated starter circuit 10 a, which is connected via the clutch 14 , such as the main drive friction clutch, and a transmission input shaft 15 to a transmission 12 , such as a three-shaft transmission, with several synchronized ratios. Fuel is metered to the engine via a throttle valve assembly 16 , which includes a throttle valve 18 that is actuated via the accelerator pedal 19 . The invention is equally applicable to gasoline engines and to diesel engines with electronic or mechanical fuel injection.

The clutch 14 is actuated, for example, via a release fork 20 or a clutch arranged concentrically to the transmission shaft, on which, for example, a hydraulic slave cylinder 22 , which is actuated by the clutch actuation control means 38, acts. The actuation can also be done by an electric motor. In this regard, reference is made to DE 195 04 847, the content of which expressly belongs to the disclosure content of the present application.

A gear selector lever 24 is moved in a shifting gate 50 , which has two legs 51 and 52 which are connected to one another via a guide 53 , namely from the end of the leg 52 to the middle between the ends of the leg 51 . Five positions are defined by the shift gate 50 : “R” at the end of the leg 52 ; "N" midway between the ends of the guide 53 ; "S" at the connection of the leg 51 to the guide 53 ; and "+" and "-" at the outer ends of the leg 51 . Within the leg 51 , the lever 24 is biased toward the central position "S". The position "N" of the shift lever 24 corresponds to the neutral position; the "R" position corresponds to the reverse gear position, the "S" position corresponds to the forward drive position; the brief movement of the lever into the "+" position provides a command signal, on the basis of which the transmission shifts up by a gear ratio, and the brief movement of the shift lever 24 in the "-" position supplies a command signal, on the basis of which the transmission shifts down by a transmission ratio.

The positions of the lever 24 are monitored by a number of sensors, for example microswitches or optical sensors, which are arranged around the switching link 50 . Signals from these sensors are transmitted to an electronic control unit 36 . An output signal from the control unit 36 controls a shift mechanism 25 via which the gears of the transmission 12 are shifted in accordance with the movement of the shift lever 24 by the driver. The switching mechanism 25 can include, for example, hydraulic cylinders and electromagnetically actuated control valves for moving sensor elements in order to shift the various gears and shift them out of them, as disclosed, for example, in the applicant's earlier patent specification WO 97/05410, the content of which expressly relates to the disclosure content belongs to the present application.

In addition to the signals from the shift lever 24 , the control unit 36 receives signals from:
Sensor 19 a, which indicates the extent of actuation of the accelerator pedal 19 ;
Sensor 30 indicating the degree of opening of throttle valve 18 ;
Sensor 26 indicating engine speed;
Sensor 42 which indicates the speed of the clutch disc;
Sensor 34 indicating the position of the clutch slave cylinder; and
Sensor 32 which indicates the gear engaged.

The control unit 36 evaluates the signals from these sensors in order to control the actuation of the clutch 14 when starting from a standstill and when changing gear, for example as in the earlier patent specifications No. EP 0038113, EP 0043660, EP 0059035, EP 0101220 and WO 92 / 13208 of the applicant, the content of which expressly belongs to the disclosure content of the present application.

In addition to the sensors mentioned above, the control unit 36 also receives signals from the sensor system 52 of an anti-lock brake system (ABS), from the ignition switch 54 and the brake switch 56 which belongs to the main brake system, for example to the foot brake 58 of the vehicle.

A warning element, such as a warning buzzer 50 , is connected to the control unit 36 in order to draw the driver's attention to the occurrence of certain operating conditions or to warn of these. In addition to or instead of the warning buzzer 50 , a flashing warning light or other display means can be used. In addition, a gear position indicator 60 is provided which shows which gear is in gear.

The control unit 36 also monitors the gear currently shifted manually with the gear shift lever 24 with the aid of sensor 32 and the vehicle operating conditions, for example the vehicle speed with the aid of sensor 42 , the vehicle speed depending on the rotational speed of the clutch disc and the shifted gear, and the engine speed using sensor 26 . If controller 36 determines that the manual gear is not appropriate for the vehicle operating conditions, controller 36 may automatically override the manual gear and shift to a more appropriate gear.

In previously proposed power transmission systems, such as set forth under No. GB 2 302 3778, the content of which expressly belongs to the disclosure content of the present application, the control unit 36 typically switches the manual transmission ratio up or down; For example, if the currently selected gear was fourth and the engine speed fell below a pre-programmed value, the control unit 36 would automatically downshift a gear ratio, namely to third gear, and if the engine speed exceeded a pre-programmed maximum value, the control unit 36 would automatically shift up a gear ratio, namely to fifth gear. Of course, more than one automatic shift could occur if the operating conditions required it, so that shifting from fourth to third and then to second could automatically take place. Such systems can also perform automatic shifts as a function of vehicle speed rather than engine speed, with shifts occurring when the vehicle speed exceeds or drops below pre-programmed values for each gear. Such systems provide gradual switching of the gear ratios, as shown in Fig. 2.

Under certain operating conditions, for example when the driver decelerates slowly to bring the vehicle to a standstill, several automatic shifts are required if the driver does not intervene by hand. This can cause problems if, for example, the driver decelerates due to traffic conditions, but intends to accelerate again as soon as this is certain. In such circumstances, controller 36 may decide that a downshift is appropriate at the very moment the driver wants to accelerate. If there is a gear change when the accelerator pedal 19 is depressed, as is actuated, then it is likely that the response to the depression of the accelerator pedal 19 is delayed due to the at least partially disengaged clutch 14 , whereas if the lower gear is already engaged, it will become one unexpected forward thrust comes when the vehicle accelerates in lower gear.

If a vehicle decelerates in accordance with the invention described here and the speed of the vehicle is above a pre-programmed threshold value V _2nd for the second gear, then the currently manually shifted gear, for example the third, fourth or fifth, is held and the control device 36 is gripped no further measures to control overwriting and changing this gear. However, if the vehicle speed drops below the threshold value _2nd for the second gear, the control unit 36 causes the gearshift mechanism 25 to automatically switch to the second gear, see FIG. 3.

If the engine speed falls below a pre-programmed value, for example the nominal engine speed when idling, while the third, fourth or fifth gear is being held or after an automatic downshift to second gear, then the control means 36 causes the clutch actuation means 38 , 22 , 20 , disengage the clutch and prevent the engine from stalling.

If the throttle valve is opened beyond a threshold value α _low while the second gear is switched, while the vehicle speed is above a pre-programmed threshold value V _1st for the first gear, this value being lower than the threshold value V _2nd for the second gear, and further decelerates the vehicle to a speed below V _1st , then the control means 36 automatically switches from second gear to first gear (as shown by the dashed line in Fig. 3) and enables the vehicle to accelerate.

Furthermore, if the second gear is shifted and the vehicle speed falls below the threshold value _1st for the first gear while the brake 58 of the vehicle is actuated, the control means 36 automatically switches from the second gear to the first gear (as shown by the broken line in FIG Fig. 3 shown) so that the vehicle can be brought to a standstill.

In this manner, under normal control, the power transmission system downshifts in accordance with the invention described herein when the vehicle speed drops below the second gear threshold V _2nd , thereby reducing the risk of an automatic downshift being performed when the driver does so Want to accelerate the vehicle.

Different modifications can be made without changing the Deviate invention. While for example in the above Embodiment hydraulic means for actuating the clutch and the Gear shift mechanism can be used, other suitable Actuators are used, for example pneumatic or electrical Means, for example electric motors or solenoid valves.

The invention described here is also applicable to automated Manual transmission systems and fully automated transmission systems.  

A power transmission system for vehicles has a main drive clutch 14 , clutch actuation means 38 , 22 , 20 for controlling the engagement state of the clutch 14 , a transmission with multiple ratios 12 , a gear shift mechanism 25 for shifting the working ratio of the transmission and electronic control means 36 for controlling the clutch actuation means 38 , 22 , 20 and the gear shift mechanism 25 . The control means 36 are designed to maintain the shifted gear while the vehicle is decelerating but the vehicle speed is above a pre-programmed second gear threshold and to shift down from a currently shifted higher gear to the second gear when the vehicle speed falls below the second gear threshold, holding the second gear while the vehicle is decelerating and vehicle speed is below the second gear threshold, and the control means 36 cause the clutch actuation means 38 , 22 , 20 to engage the clutch 14 disengage to keep engine speed above a pre-programmed minimum.

The claims submitted with the application are drafted strikes without prejudice for obtaining further patent protection. The The applicant reserves the right to do so, so far only in the description and / or to claim the combination of features disclosed.

Relationships used in subclaims point to the others Training the subject of the main claim by the features of respective subclaim; they are not a waiver of attainment an independent, objective protection for the combination of features to understand nations of the related subclaims.  

Since the subjects of the subclaims with regard to the status of Technology can form its own and independent inventions on the priority day, The applicant reserves the right to make it the subject of independent claims or make declarations of division. You can continue to work independently Inventions contain one of the objects of the previous Have independent claims independent design.

The exemplary embodiments are not intended to limit the invention understand. Rather, there are numerous within the scope of the present disclosure Changes and modifications possible, especially such variants, Elements and combinations and / or materials, for example, by Combination or modification of individual in connection with that in the general description and embodiments as well as the claims described features and elements contained in the drawings ten or procedural steps for the expert with a view to solving the Task can be removed and combined to create a new one Subject or new process steps or process step sequences lead, also insofar as they relate to manufacturing, testing and working processes.

Claims (7)

1. A power transmission system for vehicles including a main drive clutch, clutch actuation means for controlling the engagement state of the clutch, a multi-ratio transmission, a gear shift mechanism for shifting the gear ratio of the transmission, and electronic control means for controlling the clutch actuation means and the gear shift mechanism; the control means include means for detecting the gear shift, the speed of an engine, the vehicle speed and the degree of opening of a throttle valve for the engine, the control means being designed in such a way that when the vehicle decelerates

• a) the shifted gear is held while the vehicle speed is above the pre-programmed second gear threshold; and
• b) shifting down from a currently shifted higher gear to second gear when the vehicle speed drops below the second gear threshold, holding the second gear while the vehicle is decelerating and the vehicle speed is below the second gear threshold;

the control means causing the clutch actuation means to disengage the clutch to maintain the engine speed above a pre-programmed minimum value. 2. A power transmission system according to claim 1, wherein it is pre-programmed minimum value of the engine speed around the idling speed of the engine. 3. A power transmission system according to claim 1 or 2, wherein the Control means are designed so that from the second gear to the first gear is switched over if - if the vehicle speed is below the Threshold for second gear is, but above one pre-programmed threshold for first gear - the throttle opening beyond a pre-programmed threshold that However, the vehicle continues to run at a speed below that First gear threshold is delayed. 4. A power transmission system according to any of the above Claims, wherein the control means from second to first gear downshift when the vehicle speed is below a pre-programmed threshold for first gear and one Brake of the vehicle is operated. 5. A power transmission system where the gear ratios normally switched manually and the control means from Hand shifted gear in accordance with the preceding Shift claims into second or first gear. 6. A power transmission system according to claim 5, wherein the means be provided to manually downshift the Oversteer gears. 7. A power transmission system substantially as described herein, with reference to and as shown in Figures 1 and 3.