DEVICE AND METHOD FOR CALIBRATION OF A THROTTLE ARRANGEMENT

Abstract: The invention relates to a method and a device for calibration of a throttle arrangement (2) associated with an engine (6), comprising positioning the throttle arrangement (2) in a predetermined position ( alpha 3) and locking the set position ( alpha 3) to a predetermined degree of throttle application during subsequent operation of the throttle arrangement (2). The method according to the invention is characterized in that it comprises the following steps: detection of a value ( alpha 3) corresponding to the position of the throttle arrangement (2) by means of a detector (3), and actuation of an actuation device (8, 9), whereby an acknowledgement corresponding to said predetermined degree of throttle application is generated, causing said degree of throttle application to be locked to said value ( alpha 3). The invention provides a simple and effective calibration of a throttle arrangement of a boat engine.

Description: TITLE: Device and method for calibration of a throttle arrangement. TECHNICAL FIELD: The invention relates to a method for calibration of a throttle arrangement in accordance with the preamble of appended claim 1. The invention also relates to a device for calibration of a throttle arrangement in accordance with the preamble of appended claim 7. BACKGROUND OF THE INVENTION: A throttle arrangement of the kind which comprises a lever which is pivotally mounted in a bracket is normally used for propulsion of motor boats. The lever can be positioned in a neutral position which corresponds to idling of the engine and can also be swung in the forwards and rearwards directions in the bracket for setting a predetermined degree of throttle application in the forwards or rearwards direction of the boat. Normally, the throttle arrangement is connected to the engine via a wire which transfers the movements of the lever in a mechanical manner. Throttle arrangements which comprise an electrical detector by means of which the position of the lever is detected have also been developed in recent years. This position can be read by a control unit. The control unit controls the operation of the boat's engine according to the set degree of throttle application. In the field of throttle arrangements, a problem may arise due to the fact that the lever may present a relatively large stroke, i.e. it requires a large geometrical space in order to be adjustable so as to assume all positions ranging from full throttling in the forwards direction to full throttling in the rearwards direction. As a consequence, if for example the throttle arrangement is mounted close to other objects in the boat the entire stroke of the lever cannot be used. For this reason, there is a need to be able to calibrate the setting of the throttle arrangement, for example so that full throttling is obtained when the lever is positioned halfway along its stroke. In particular, there is a demand for devices and methods for calibration of the modern type of throttle arrangement which comprises a detector which is connected to a control unit. Another problem in connection with the above-mentioned throttle arrangement arises when the engine is idling. Depending, for example, on the type of boat which is used, how the throttle arrangement is set and how the engine is arranged in the boat, there is a risk that resonance may arise at the idling speed of the engine. This may lead to problems in the form of heavy noise and unwanted vibrations in the boat. Consequently, there is a demand for a fine tuning of the idling speed of the engine in a simple and effective manner, so that a setting of the throttle arrangement in the idling position always provides an idling speed at which the said resonance phenomenon can be minimized. SUMMARY OF THE INVENTION: Consequently, the object of the invention is to solve the above-mentioned problems and to provide a method which allows a simple and effective calibration of a throttle arrangement primarily intended for boat engines. This is accomplished by means of a method of the kind initially mentioned, the characterizing features of which will be apparent from subsequent claim 1. Said object is also accomplished by means of a device of the kind initially mentioned, the characterizing features of which will be apparent from subsequent claim 7. In this context, the term "calibration" is intended to describe the fact that a predetermined set position of the throttle arrangement is locked to a predetermined, desired degree of throttle application of the engine. BRIEF DESCRIPTION OF THE DRAWINGS: The invention will be described in the following in greater detail with reference to the annexed drawings, in which Fig. 1 shows the invention in a schematical form, and Fig. 2 shows the invention during calibration. PREFERRED EMBODIMENTS: Fig. 1 shows in a simplified, schematical manner a device according to the present invention. According to a preferred embodiment, the device comprises a bracket 1 which is intended to be arranged in a motor boat. A throttle arrangement 2 in the form of a lever is mounted in the bracket 1. In a manner which is known, the throttle arrangement 2 is pivotally arranged around an axis of rotation (not shown) which is arranged in the bracket 1. In this manner, the throttle arrangement 1 can be swung forwards and backwards in the bracket 1. The throttle arrangement 2 can be set in a certain neutral position N which corresponds to idling of the engine. In this position (which is the position shown in Fig. 1), the throttle arrangement 2 is preferably essentially vertically arranged. The throttle arrangement 2 can also be set in a position F which corresponds to the throttle arrangement 2 being within the angle interval α,. When the F position is assumed, a gear for propulsion of the engine in the forwards direction is engaged. The magnitude of throttle application increases within the F position from a minimal degree of throttle application to a maximum degree of throttle application the further away from the vertical position the throttle arrangement 2 is positioned. In a corresponding manner, the throttle arrangement 2 can be positioned in a position R for reverse propulsion. This corresponds to the angle range α 2 . Furthermore, the throttle arrangement 2 is connected to a detector in the form of a rotary potentiometer 3, the resistance of which depends on the position in which the throttle arrangement 2 is set. The rotary potentiometer 3 is connected to a control unit 4 via an electrical connector 5. Preferably, the control unit 4 is computer- based and is adapted to determine the magnitude of the resistance of the potentiometer 3. Based on this magnitude, a corresponding value of the degree of throttle application is derived in the control unit 4, i.e. a value corresponding to the current angular position of the throttle arrangement 2 in the bracket 1. The control unit 4 is connected to the boat's engine 6, which may be a diesel engine, petrol engine or an engine of some other type. In a manner which is known, the engine 6 can be fed with a fuel mixture via an injection device (not shown). The control unit 4 is adapted to influence the injection device to deliver a suitable fuel mixture to the engine 6, so that the engine can be operated with a degree of throttle application which corresponds to a set position of the throttle arrangement 2, i.e. which depends on the current value of the resistance of the potentiometer 3. An engine speed counter 7 is preferably arranged in connection with the engine 6, which speed counter forwards a value representing the engine speed to the control unit 4. Furthermore, the throttle arrangement 2 may be provided with a switch (not shown) which senses whether the N position is engaged or not. This condition can be detected by the control unit 4 and may for example be used in order to prevent the engine from being started unless the throttle arrangement 2 is positioned in the N position. In accordance with the invention, an actuation device 8 is connected to the control unit 4. The actuation device 8 is preferably constituted by a keyboard comprising a number of buttons or keys 9, which for example may be three in number. The actuation means 8 can be used in the following manner during calibration of the throttle arrangement 2. When the throttle arrangement 2 is to be calibrated, a check whether the throttle arrangement 2 is positioned in the N position is first performed in the control unit 4. If this is the case, a predetermined key 9 on the actuation means 8 is pressed. Preferably, this can be acknowledged by means of a light (not shown) or the like on the actuation means 8 or the bracket 1. This indicates that the calibration is about to commence. Thereafter, the throttle arrangement 2 is set in a certain angular position α 3 , in accordance with that shown in Fig. 2, which is a simplified drawing of a throttle arrangement 2 in a bracket 1. The current angular position α 3 is intended to correspond to a certain magnitude of the degree of the throttle application, for example full throttling in the forwards direction. When the throttle arrangement 2 has been positioned in the desired angular position α 3 , a certain key of the actuation means 8 is pressed. This key is chosen beforehand so as to correspond to the desired degree of throttle application. Consequently, it constitutes an acknowledgement of the fact that the desired degree of throttle application is to be locked to the desired angular position. The control unit 4 receives the signal from the actuation means 8 and detects that the current key corresponds to full throttle application. Thereafter, the control unit 4 stores both the current value of the resistance of the potentiometer 3 (which corresponds to the angular position 3 ) and the current degree of throttle application. Said values are stored in a memory unit 10 associated with the control unit 4. In this manner, the angular position α 3 is set so as to correspond to full throttling. When the engine 6 is subsequently started, a positioning of the throttle arrangement in the angular position 3 will be interpreted as a maximum degree of throttle application. The calibration may proceed with setting of additional angular positions which can be locked to predetermined operational conditions (i.e. the degree of throttle application and the direction of propulsion) of the engine 6, by pressing keys on the actuation means 8. In accordance with a particular embodiment, the invention can be employed for calibration of the idling speed of the engine 6. In this case, the control unit 4 can be set to a certain operational condition by pressing a particular key on the actuation means 8. Thereafter, the engine is started in the conventional manner. In this present operational condition, the entire stroke of the lever now corresponds to a certain range of idling speeds, preferably from 550 to 700 rpm. The lever may now be positioned in a position in which a suitable idling speed is obtained, i.e. a speed which provides idling without generating any resonant noise or unwanted vibrations. Thereafter, a predetermined key on the actuation means 8 is pressed. This signifies that the current value of the speed of the engine 6 is detected by means of the speed detector 7 and is stored in the memory unit 10. The calibration of the idling speed is terminated by setting the throttle arrangement in the N position, which is detected by the control unit 4. During subsequent operation of the engine, the N position is locked to the idling speed which was stored in the memory unit 10 as stated above. The invention is not limited to the above-mentioned embodiments, but may be varied within the scope of the subsequent claims. For example, various types of detectors 3 can be used. Furthermore, the actuation device 7 can be operated in different ways, for example by entering a certain sequence of keys in the form of a code. Altematively, the operation may be carried out by keeping a certain key pressed for a certain time, which corresponds to a certain degree of throttle application. Finally, the throttle arrangement 2 may comprise two levers which are mounted in one bracket. An arrangement of this type can be used in boats with two engines.

Claims: CLAIMS : 1. Method for calibration of a throttle arrangement (2) associated with an engine (6) , comprising positioning the throttle arrangement (2) in a predetermined position ( 3 ) and locking the set position (α 3 ) to a predetermined degree of throttle application during subsequent operation of the throttle arrangement (2), c h a r a c t e r i z e d i n that it comprises the following steps: - detection of a value (α 3 ) corresponding to the position of the throttle arrangement (2) by means of a detector (3), and - actuation of an actuation device (8, 9) , whereby an acknowledgement corresponding to said predetermined degree of throttle application is generated, causing said degree of throttle application to be locked to said value (α 3 ). 2. Method according to claim 1, c h a r a c t e r i z e d i n that the actuation of the actuation device (8, 9) initiates storing of said value (α 3 ) and a value corresponding to said predetermined degree of throttle application in a memory unit (10). 3. Method according to claim 2, the operation of the engine (2) being controlled by a control unit (4), c h a r a c - t e r i z e d i n that the control unit (4) reads the contents of said memory unit (10) in connection with controlling the engine (6) . 4. Method according to claim 3, c h a r a c t e r i z e d i n that the condition of the detector (3) is detected by the control unit (4) and that the operation of the engine (6) is controlled by the control unit (4) depending on the condition of the detector (3) . 5. Method according to any one of claims 3 or 4, c h a r a c t e r i z e d i n that said control of the actuation means (8, 9) comprises pressing at least one key (9) on a keyboard (8) , wherein a predetermined acknowledgement signal is fed to the control unit (4). 6. Method according to claim 1, c h a r a c t e r i z e d i n that it is performed when the engine (6) is running and that said predetermined degree of throttle application is constituted by the idling speed of the engine (6). 7. Device for calibration of a throttle arrangement (2) associated with an engine (6), comprising a detector (3) for detection of the set position (α 3 ) of the throttle arrangement (2) and locking means (8, 9, 10), wherein said set position (α 3 ) corresponds to a predetermined degree of throttle application during subsequent operation of the throttle arrangement (2), c h a r a c t e r i z e d i n that said means (8, 9, 10) comprises an actuation device (8, 9) which during actuation is adapted for generating an acknowledgement corresponding to said predetermined degree of throttle application, whereby said degree of throttle application is locked to said position (α 3 ).

Inventors: DAHLGREN MATS, NESTVALL PER, DAHLGREN, MATS, NESTVALL, PER
Applicants: DAHLGREN MATS, NESTVALL PER, VOLVO PENTA AB, AB VOLVO PENTA, DAHLGREN, MATS, NESTVALL, PER
Application year: 1996
Main classification: F02D11
IPC codes: B63H21, F02D11, F02D41, F02D45