Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
  • F16D57/00—Liquid-resistance brakes; Brakes using the internal friction of fluids or fluid-like media, e.g. powders
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
  • B60T10/00—Control or regulation for continuous braking making use of fluid or powdered medium, e.g. for use when descending a long slope
  • B60T10/02—Control or regulation for continuous braking making use of fluid or powdered medium, e.g. for use when descending a long slope with hydrodynamic brake
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
  • B60T13/00—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems
  • B60T13/10—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with fluid assistance, drive, or release
  • B60T13/58—Combined or convertible systems
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01P—COOLING OF MACHINES OR ENGINES IN GENERAL; COOLING OF INTERNAL-COMBUSTION ENGINES
  • F01P3/00—Liquid cooling
  • F01P3/20—Cooling circuits not specific to a single part of engine or machine
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01P—COOLING OF MACHINES OR ENGINES IN GENERAL; COOLING OF INTERNAL-COMBUSTION ENGINES
  • F01P2023/00—Signal processing; Details thereof
  • F01P2023/08—Microprocessor; Microcomputer
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01P—COOLING OF MACHINES OR ENGINES IN GENERAL; COOLING OF INTERNAL-COMBUSTION ENGINES
  • F01P2025/00—Measuring
  • F01P2025/08—Temperature
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01P—COOLING OF MACHINES OR ENGINES IN GENERAL; COOLING OF INTERNAL-COMBUSTION ENGINES
  • F01P2037/00—Controlling
  • F01P2037/02—Controlling starting
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01P—COOLING OF MACHINES OR ENGINES IN GENERAL; COOLING OF INTERNAL-COMBUSTION ENGINES
  • F01P2060/00—Cooling circuits using auxiliaries
  • F01P2060/06—Retarder
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01P—COOLING OF MACHINES OR ENGINES IN GENERAL; COOLING OF INTERNAL-COMBUSTION ENGINES
  • F01P2060/00—Cooling circuits using auxiliaries
  • F01P2060/18—Heater

Definitions

• This invention relates to a method and an arrangement of the types in the preambles to claims 1 and 7 respectively.
• a method of prior art is to equip motor vehicles, particularly heavier vehicles such as trucks and buses, with a hydrodynamic auxiliary brake incorporated in the drive line between the engine and the driving wheels of the vehicle.
• a hydraulic retarder is intended primarily to be switched on when necessary to help retard the vehicle.
• a further method of prior art is to use a retarder for a purpose other than merely to retard the vehicle.
• DE 3 408 057 which describes a design in which a retarder is used to increase the load on the driving engine of the vehicle. The objective is then to increase the temperature of the exhaust gases from the engine, thereby burning away deposits formed in a soot filter in the exhaust system.
• GB 2 134 245 describes a hydrodynamic brake which is used to accelerate the heating of the coolant in the engine cooling system at low load.
• a hydrodynamic brake which is used to accelerate the heating of the coolant in the engine cooling system at low load.
• computer controlled or electronically controlled fuel injection e.g. Scania's EDC system
• the fuel injection control system which is connected in this way to different transmitters, therefore contains information on the current operating condition of the vehicle. This information can also be used for other computer-based control systems incorporated in the vehicle, such as the control system for the vehicle retarder.
• the retarder control system is normally and conventionally designed for optimum control of the retarder according to different operating parameters.
• the retarder control system may have programmed in it, for example, blocks which prevent the retarder from being activated at the same time that the driver actuates the throttle. Such driving behaviour, with simultaneous throttle and brake activation, is normally inappropriate.
• the objective of the invention is to be able to use the hydraulic retarder in a motor vehicle for accelerating engine heating.
• the requirement here is to be able to switch on the retarder acting as a hydrodynamic brake when the vehicle is started so that the power of the retarder developed during braking can be used as soon as possible to heat the coolant in the engine cooling system.
• This heating is achieved firstly because the engine is now forced to operate at an increased load due to the braking action of the retarder, which increases the heat developed during combustion, and secondly because of the braking effect which the retarder "brakes away", and which results in heating of the retarder hydraulic oil whose heat is absorbed by the engine coolant via a heating exchanger acting between the retarder hydraulic oil and the coolant.
• the principle concept of the invention is therefore to eliminate the blocking function preventing driving with simultaneous throttle and retarder braking incorporated in the computer controlled retarder control system using the proposed method and arrangement.
• the retarder can therefore be set to perform braking work at the same time that the engine is throttled, thereby increasing the engine load and accelerating heating of the engine coolant, both due to the increased loading of the engine and absorption of heat from the retarder hydraulic fluid.
• the engine heating function of the engine through management of heat developed by the retarder when it is performing braking work means that operation of the accelerator pedal (throttle) is prevented from deactivating or switching off the retarder.
• This enables the engine and the retarder to be "run” simultaneously (i.e. the engine operates under throttle whilst the retarder performs braking work), which results in rapid heating of the coolant in the vehicle cooling system and therefore rapid heating of the engine, as well a heating of the interior of the vehicle, because this is in turn heated by the engine coolant.
• a further advantage of rapid heating of the engine is that it reaches its operating temperature more quickly, with a correspondingly faster reduction of its exhaust emissions. In cold starts and during heating diesel engines emit so-called white smoke, and rapid heating reduces the nuisance this causes in a shorter time.
• Fig. 1 shows very diagrammatically the components, essential to the invention, of an arrangement for controlling the engine heating function of a diesel engine driven vehicle with a retarder system designed to accelerate engine heating.
• Fig. 2 shows in block diagram form a flow chart of the engine heating function.
• Fig. 1 shows diagrammatically an arrangement which enables the heating of a diesel engine to be accelerated in a motor vehicle equipped with a switchable hydraulic retarder 2, which can be used either as a hydrodynamic auxiliary brake for retarding the vehicle, or as an aid to accelerating the engine heating.
• the motor vehicle itself is shown in Fig. 1 only in the form of an engine driven crankshaft 4 which, via a coupling 6, transmits the driving force of the engine to a gearbox 8. From gearbox output shaft 10 the driving force is then transmitted by conventional means to the subsequent components of the vehicle drive line not shown here.
• An oil sump 12, an accumulator 14 and an oil cooler 16 are also connected to hydraulic retarder 2.
• the activation (switching on) and deactivation (switching off) of retarder 2 is controlled electrically by a computer based control 18, which is connected to retarder 2 by a signal cable 20.
• a computer based control 18 incorporates a blocking function which prevents the retarder from being activated at the same time as the engine is throttled.
• the blocking function also means that when the retarder is switched on it is automatically switched off as soon as the throttle is activated.
• the arrangement shown is therefore normally incorporated essentially in a vehicle equipped with a retarder, but it is also used according to this invention to enable the retarder to be activated when the engine is started, so that the engine load is increased by the same even when the throttle is activated, thereby accelerating heating of the coolant in the ordinary engine cooling system.
• This heating function is activated by eliminating the blocking function preventing driving with simultaneous retarder braking and throttle incorporated in the computer controlled retarder control system.
• control unit 18 For controlling retarder 2, both when driving with the heating function activated and not activated, computer 18 must have knowledge of a number of relevant control parameters. Computer 18 obtains information on these control parameters via signal cables from the units.and transmitters shown in Fig. 1 , among other things.
• the control system for retarder 2 interacts closely with the control system for the electronically controlled engine fuel injection. In practice both these control systems are designed as separate units, but because of their close interaction they have been integrated into control unit 18 in Figure 1.
• the controls operated by the driver are of course controls whose effect on the operation of the vehicle and the engine are highly significant in this connection. Adjusting devices, not shown in greater detail here, which transmit state signals to control unit 18 via signal cables 28, 30 and 32 respectively, are therefore connected to these pedals.
• An engine speed transmitter 48 and a coolant temperature transmitter 50 are also connected to control unit via signal cables 49 and 51 respectively. Because this is an electrical control system control unit 18 is also connected via a cable 34 to a switch 36, whose actuation switches on the electricity supply to the system. This switch 36 can suitably be operated with the starting key.
• the above-mentioned blocking function preventing driving with simultaneous throttle and braking with the retarder is eliminated in the arrangement shown by switching on a heating function stored in control unit 18.
• the heating function can be activated automatically when starting or by means of a special control.
• activation takes place as follows.
• Retarder control unit 18 incorporates a known constant speed (cruise control) function which, when activated, ensures that the vehicle braked to a constant speed, e.g. when driving downhill.
• This constant speed (cruise control) function is activated by means of a control switch 38 which can be activated by the driver.
• this control switch 38 is also used for activating the heating function.
• One advantage of this is that this component already exists, and the modification required is limited to the software of control unit 18.
• Control unit 18 incorporates software which detects this simultaneous activation of control switch 38 and starter 36.
• control switch 38 When only control switch 38 is activated, it operates only as designed, i.e. for activating the constant speed (cruise control) function.
• control switch 38 can be activated via a control button mounted at the outer free end of a iever 40, whose position setting operates an adjusting device 42 which controls the activation of retarder 2 via signal cable 44 and computer 18.
• the figure shows five alternative setting positions of Iever 40. These positions are designated 0, 1 , 2, 3 and 4, and correspond to gradually increasing braking moments generated by retarder 2. These braking moments may, for example, be 500 Nm, 1000 Nm, 2000 Nm and 3000 Nm for Iever positions 1 , 2, 3 and 4 respectively.
• An indicator 53 which indicates when the heating function has been switched on, is suitably mounted on the engine instrument panel.
• the flow chart contains six function blocks 52, 54, 56, 58, 60 and 62 arranged in sequence.
• the top block 52 it is established whether the power has been switched on in the system, i.e. whether the power supply to the system has been switched on by turning on starter 36, which is the case if the starting key has been turned to the power on position.
• the system senses whether control switch 38 has been activated, i.e. whether its control button has been pressed. If this is the case the next stage of the heating function follows, namely the step indicated in block 54, whereby sensing takes place to determine whether the coolant temperature is below
• the retarder is not set to brake, the retarder is not activated either and the heating function is not used in this case.
• the retarder has been switched on the monitoring of the coolant temperature indicated in the next block 58 commences. As long as this coolant temperature remains below a predetermined value, preferably the value corresponding to normal engine operating temperature, which in this example is 85°C, the heating function will remain switched on, but as soon as the coolant temperature reaches or exceeds 85°C (implying that the required engine heating has been completed), the next step indicated in block 60 follows, namely disconnection of the heating function, which leads to termination of the process according to the invention, as indicated in block 62. This also means that the blocking function of the retarder is reactivated.
• an activation of the heating function operation of accelerator pedal 26, as when throttling by pressing the accelerator pedal, does not disconnect retarder 2 but instead enables the engine and retarder to operate simultaneously, thereby achieving an acceleration of the engine heating due both to the engine's own increased heat development and the heat generated during braking of the retarder, which contributes to rapid heating of the coolant in the engine cooling system and therefore to rapid heating of the engine itself and hence also the interior of the vehicle.
• control switch 38 by pressing its control button and keeping it pressed.
• the driver then switches on the ignition and starts the engine by means of the starting key, so that starter 36 is activated at the same time as control switch 38 is activated.
• the engine is then allowed to idle for a few seconds, e.g. for three seconds.
• control switch 38 deactivates control switch 38 by releasing the control button pressed until that point.
• the driver then sets the vehicle in motion with a suitable throttle by pressing accelerator pedal 26 so that the vehicle gains speed.
• the driver then commences braking, at the first most suitable opportunity, by means of retarder 2, which is activated by setting Iever 40 to the desired braking moment position whilst at the same time increasing the throttle by pressing accelerator pedal 26.
• the heating power developed by the retarder (which contributes to increasing the temperature of the coolant) is determined by the position to which Iever 40 is set (see Fig. 1 ), i.e. by the braking moment set for the retarder.
• the entire heating process takes place - once initiated by the driver - by means of the retarder control system shown in Fig. 1.
• the most important component in this system is of course control unit 18 based on microcomputer technology.
• the control laws which enable the method according to the invention to be implemented could in practice be established by suitable modification of the software incorporated in retarder control system 18.
• the required program control can be arranged in a separate control unit.
• control unit 18 and the arrangement described is designed to operate conventionally to control the retarder and engine in all other operating conditions when the heating function is not activated.
• the blocking function incorporated in the control unit is active, and if the driver activates the accelerator pedal in this case braking with the retarder is automatically disconnected (provided that the retarder has been activated).
• the description relates to an advantageous embodiment in which the diesel engine fuel injection is controlled electrically.
• the fuel injection can be controlled mechanically, but this requires such an arrangement to be supplemented by the components necessary for sensing the operating parameters concerned.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Transportation (AREA)
• Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Control Of Throttle Valves Provided In The Intake System Or In The Exhaust System (AREA)
• Control Of Vehicle Engines Or Engines For Specific Uses (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

Family

ID=20386547

Family Applications (1)

Country Status (3)

Cited By (8)

Families Citing this family (2)

Citations (4)

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• 1992
  • 1992-06-22 SE SE9201893A patent/SE507435C2/sv not_active IP Right Cessation
• 1993
  • 1993-06-17 DE DE4392959T patent/DE4392959T1/de active Pending
  • 1993-06-17 DE DE4392959A patent/DE4392959B4/de not_active Expired - Lifetime
  • 1993-06-17 WO PCT/SE1993/000536 patent/WO1994000323A1/en active Application Filing

Patent Citations (4)

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