DESC:TECHNICAL FIELD
Embodiment of disclosure generally relates to an engine speed harmonizer or synchronizer to reduce jerks and clutch wear during gear shifting.

BACKGROUND OF THE DISCLOSURE
The present day automobiles powertrain consists of components like Engine, clutch, gear box, axle and wheels for driving the vehicle. Control components such as accelerator pedal, gear shift lever and clutch pedal to control the above mentioned components. Apart from these, there are controls like brake pedal and steering wheel to control the speed and direction of the vehicle.

Out of different type of engine and transmission options, manual shift gear box is one of the types, wherein, the gear shifting is carried out manually. During gear shifting, the engine has to be engaged to the transmission and disengaged from the transmission after gear engagement. This operation of engaging and disengaging of the gears is done by the clutch along with gear lever shifting. During the process of gear shifting, the engine speed and the clutch speed is not synchronized due to which there occurs shift shocks, jerky feel during gear shifting. These shocks are not appreciated by the driver. Recent vehicles are built with electronically controlled engine.

Moreover, the clutch liner life is also affected due to the difference in revolution of the Engine and gear box input shaft. The clutch has to do more work during gear shifting and will dissipate more heat leading to clutch liner wear. This becomes more critical in hilly regions while negotiating series of hair pin bends, city and in congested traffic scenarios.

To overcome the above mentioned problems there is a need for synchronization of the clutch speed with engine speed and rotation of an engine with rotation of the gear box input shaft.

SUMMARY OF THE DISCLOSURE
The shortcomings of the prior art are overcome and additional advantages are provided through the provision of the present disclosure. Additional features and advantages are realized through the techniques of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered a part of the disclosure.

In one embodiment of the present disclosure, an engine speed synchronizer is provided. The engine speed synchronizer comprising a first sensor for sensing position of a clutch pedal, a second sensor for measuring speed of a gear box input shaft, a third sensor for measuring rotational speed of an engine flywheel. An electronic controller unit (ECU) is communicably connected to the first sensor, the second sensor and the third sensor. Based on received signals from the first sensor, the second sensor and the third sensor, the ECU synchronizes rotation of an engine with rotation of the gear box input shaft by controlling fuel input to the engine.

In one embodiment, the first sensor sends signals to the ECU only when the clutch pedal is travelled in between 65 to 100 % with respect to clutch pedal travel.

In one embodiment, the first sensor is provided at clutch pedal of a vehicle.

In one embodiment, the second sensor is provided at the gear box input shaft of the vehicle.

In one embodiment, the third sensor is provided at an engine block of the vehicle.

In one embodiment, the engine speed synchronizer further comprises a cam mechanism for varying position of the clutch pedal due to travel of the clutch pedal. The cam mechanism comprises a worm wheel mounted coaxial on a boss of the clutch pedal, a worm supported by brackets on the clutch pedal and meshed with the worm wheel and an axial cam profile slidingly contacting a plunger of the first sensor.

In one embodiment, a worm adjuster nut is configured in the cam mechanism for fine adjustment positioning of the plunger onto the axial cam profile.

In one embodiment of the present disclosure, a method of synchronizing engine speed using the engine speed synchronizer is provided. The method comprising acts of sensing clutch pedal operation by a first sensor, measuring speed of a gear box input shaft by a second sensor, measuring rotational speed of an engine flywheel by a third sensor. After the electronic control unit (ECU) receives the signals from the first sensor, the second sensor and the third sensor the ECU controls fuel supply to engine to synchronize rotation of an engine with rotation of the gear box input shaft.

The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The novel features and characteristic of the disclosure are set forth in the appended claims. The disclosure itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying figures. One or more embodiments are now described, by way of example only, with reference to the accompanying figures wherein like reference numerals represent like elements and in which:

Fig. 1 shows an engine speed synchronizer according to an embodiment of the present disclosure.

Fig. 2 shows a cam mechanism incorporated in the clutch pedal according to an embodiment of the present disclosure.

Fig. 3 shows clutch pedal movement according to an embodiment of the present disclosure.

Figs. 4 and 5 show graphs to illustrate engine curve according to an embodiment of the present disclosure.

The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.

DETAILED DESCRIPTION OF THE DISCLOSURE
The foregoing has broadly outlined the features and technical advantages of the present disclosure in order that the detailed description of the disclosure that follows may be better understood. Additional features and advantages of the disclosure will be described hereinafter which form the subject of the claims of the disclosure. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present disclosure. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the disclosure as set forth in the appended claims. The novel features which are believed to be characteristic of the disclosure, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present disclosure.

It is to be noted at this point that all of the above described components, whether alone or in any combination, are claimed as being essential to the disclosure, in particular the details depicted in the drawings and reference numerals in the drawings are as given below.

Reference will now be made to the exemplary embodiments of the disclosure, as illustrated in the accompanying drawings. Wherever possible, same numerals will be used to refer to the same or like parts.

Referral Numerals
Referral Numerals Description
1 Engine
2 Manual transmission
3 Clutch
4 Clutch pedal
6 First sensor
6a Plunger
7 Second sensor
8 Gear box input shaft
9 Third sensor
10 Engine flywheel
11 Engine control unit (ECU)
12 Cam mechanism
12a Worm wheel
12b Worm
12c Boss
12d Bracket
12e Axial cam profile
12f Worm adjuster nut
100 Engine speed synchronizer

A powertrain of a vehicle comprises an engine, a manual transmission and an engine clutch. The engine clutch includes a clutch pedal arranged to individually engage and disengage speed gears of the manual transmission. The engine clutch having an engine shaft is connected to an output side of the engine and a transmission side is connected to an input shaft of the manual gearbox. The engine speed synchronizer is configured in the powertrain of the vehicle. The engine speed synchronizer comprises of a first sensor for sensing a position of the clutch pedal, a second sensor for measuring a gear box input shaft speed and, a third sensor for measuring rotational speed of an engine flywheel. Further the engine speed synchronizer comprises an Engine Controller Unit (ECU) which is connected to the first sensor, the second sensor, and the third sensor is configured to synchronize rotation of the engine with rotation of the gear box input shaft.

In one embodiment, the speed synchronization starts its operation only from 1st to 2nd gear shift operation and thereafter, till up to a maximum up shifts available on that vehicle. The similar synchronization happens during the downshifts until 1st gear.

In one embodiment, the ECU senses pressed condition of clutch pedal and if the clutch pedal is travelled in between 65 to 100 % with respect to clutch pedal travel, and after sensing the gear shift by monitoring sudden change in gear box rpm, sensed via gearbox input sensor and partially monitored by engine speed sensor as a reference speed, the engine speed synchronizer synchronizes till the start of the engagement of the clutch with gear. Thereafter, the synchronizing process is stopped. However, in case of manual intervention on acceleration pedal in the vehicle, the process of synchronization is stopped.

During synchronization process, speed curve of engine follows the speed curve of the gear box input shaft as close as possible till the defined clutch pedal position is in the range of 65 to 100 % with respect to clutch pedal travel.

Fig. 1 illustrates an engine speed synchronizer or harmonizer (100) according to an embodiment of the present disclosure. The engine speed synchronizer (100) is configured to harmonize engine speed with manual transmission having mechanical clutch. A powertrain of a vehicle includes an engine (1), a manual transmission (2) and a clutch (3). The clutch (3) comprises a clutch pedal (4) arranged to individually engage and disengage speed gears of the manual transmission (2). The clutch (3) having an input shaft (8) is connected to an output side of the engine (1) and a transmission side connected to an input shaft (8) of the manual transmission (2). The engine speed synchronizer (100) comprises a first sensor (6) for sensing an operation of the clutch pedal (4), a second sensor (7) for measuring speed of a gear box input shaft (8), a third sensor (9) for measuring rotational speed of an engine flywheel (10). The engine speed synchronizer also comprises an Electronic Controller Unit (ECU) (11) configured to synchronize rotation of the engine (1) with the rotation of the clutch (3) and the gear box input shaft (8) by controlling the fuel input to the engine (1). Further, with reference to an operation of the clutch pedal (4) by the input from the clutch pedal senor (6) the speed is controlled.

Sequence of operation of engine and clutch speed synchronization
In an exemplary embodiment of the present disclosure, the speed synchronization operation starts only after 1st gear (not shown) is engaged, i.e., after 1st to 2nd gear shift (not shown) operation and thereafter till all upshifts in the vehicle. During the clutch engagement and shifting of gear from 2nd, 3rd, 4th & 5th (not shown), the fuel quantity is controlled to synchronize engine and the gear box input speed. Similar synchronization also occurs during the downshifting operations until the 1st gear.

In one embodiment, the ECU senses pressed condition of clutch pedal and if the clutch pedal is pressed in between 65 to 100 % with respect to clutch pedal movement, (as shown in Fig. 3) and after sensing the gear shift by monitoring sudden change in gear box rpm, sensed via gearbox input sensor and partially monitored by engine speed sensor as a reference speed, the engine speed synchronizer synchronizes till the start of the engagement of the clutch with gear. Thereafter, the synchronizing process is stopped. However, in case of manual intervention on acceleration pedal in the vehicle, the process of synchronization is stopped.

During synchronization process, speed curve of engine follows the speed curve of the gear box input shaft as close as possible till the defined clutch pedal position is in the range of 65 to 100 % of the clutch pedal.
Fig. 2 illustrates a cam mechanism (12) incorporated in the clutch pedal (4) is provided according to an embodiment of the present disclosure. The cam mechanism (12) consists of a worm wheel (12a) mounted coaxial on the boss (12c) of the clutch pedal (4) and helps in swivel around it during clutch pedal (4) actuation. The worm wheel (12a) is further an engaged with worm (12b) supported by the brackets (12d) on the clutch pedal (4). The worm (12b) has an axial cam profile (12e) whose surface is in contact with plunger (6a) of the sensor (6). When the clutch pedal (4) is pressed the whole unit (12 a, 12b, 12c, 12d, 12e, 12f) rotates along with it thereby pushing the plunger (6a) of the sensor (6). If fine adjustment in positioning the plunger (6a) is required, the worm adjuster nut (12f) is rotated manually in clockwise or anticlockwise direction in clutch pedal is in upright position.

Fig. 3 illustrates the clutch pedal (4) movement according to an embodiment of the present disclosure. As illustrated, movement of the clutch pedal (4) is divided into three portions/points. Initial position of the clutch pedal (4) is indicated as floor. Disengagement of the clutch (3) starts when the clutch pedal (4) travels 30% with respect to pedal travel. Once the clutch pedal (4) travels further it reaches clutch engagement point. In other words, when clutch pedal (4) travels 40% with respect to pedal travel it reaches clutch engagement point. Further, clutch reaches to the clutch modulation points when it travels up to 60% with respect to pedal travel. The zone between clutch engagement point and the modulation point is called as modulation zone.

Figs. 4 and 5 show graphs to illustrate engine curve according to an embodiment of the present disclosure.

Advantages
In one embodiment of the present disclosure, the engine speed synchronizer and the method disclosed in the present disclosure is beneficial to reduce shift shocks and clutch wear and thus reduces overall maintenance cost of the vehicle.

In one embodiment of the present disclosure, the engine speed synchronizer is add on feature for any automobile which will enable user to drive the vehicle to match engine speed to input drive shaft speed.

In one embodiment, the clutch pedal sensor to monitor the point of disengagement, engagement and modulation zone is more accurate as compared to sensor on clutch slave cylinder side.

In one embodiment, the engine speed synchronizer, the synchronization of engine speed helps to keep the inertia of the vehicle.

In one embodiment, the implementation of synchronizers play an essential role in driver comfort during operation of the clutch pedal while gear shifting.

In one embodiment, the integration of steps of obtaining information from various sensors ensures highest quality and cost effectiveness.

In one embodiment, the ECU performs the synchronization immediately after gear shift based on the speed of the gearbox input shaft, clutch pedal position and rotational speed of flywheel.

In one embodiment, the ECU withdraws the speed synchronization in case of any intervention based on driver’s or user’s response.

In one embodiment, the disclosed engine speed synchronizer is applicable in taxi vehicles, tourist vehicles and in personal vehicles as well.

The foregoing description is a specific embodiment of the present invention. It should be appreciated that this embodiment is described for purpose of illustration only, and that numerous alterations and modifications may be practiced by those skilled in the art without departing from scope of the disclosure. It is intended that all such modifications and alterations be included in so far as they come within the scope of the disclosure as claimed or the equivalents thereof.

Equivalents
With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.

It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B.”

While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.

,CLAIMS:We claim:
1. An engine speed synchronizer (100), comprising:
a first sensor (6) for sensing position of a clutch pedal (4);
a second sensor (7) for measuring speed of a gear box input shaft (8);
a third sensor (9) for measuring rotational speed of an engine flywheel (10);
an electronic controller unit (ECU) (11) communicably connected to the first sensor (6), the second sensor (7) and the third sensor (9), wherein the ECU (11), based on received signals from the first sensor (6), the second sensor (7) and the third sensor (9), synchronizes rotation of an engine with rotation of the gear box input shaft (8) by controlling fuel input to the engine.

2. The engine speed synchronizer (100) as claimed in claim 1, wherein the first sensor (6) sends signals to the ECU only when the clutch pedal (4) is travelled in between 65 to 100 % with respect to clutch pedal travel.

3. The engine speed synchronizer (100) as claimed in claim 1, wherein the first sensor (6) is provided at clutch pedal (4) of a vehicle.

4. The engine speed synchronizer (100) as claimed in claim 1, wherein the second sensor (7) is provided at the gear box input shaft (8) of the vehicle.

5. The engine speed synchronizer (100) as claimed in claim 1, wherein the third sensor (9) is provided at an engine block of the vehicle.

6. The engine speed synchronizer (100) as claimed in claim 1, further comprises a cam mechanism (12), the cam mechanism (12) comprising:
a worm wheel (12a) mounted coaxial on a boss (12c) of the clutch pedal (4);
a worm (12b) supported by brackets (12d) on the clutch pedal (4) and meshed with the worm wheel (12a);
an axial cam profile (12e) slidingly contacting a plunger (6a) of the first sensor (6), for varying position of the clutch pedal (4) due to pressing of the clutch pedal (4).

7. The engine speed synchronizer (100) as claimed in claim 1, a worm adjuster nut (12f) is configured in the cam mechanism (12) for fine adjustment positioning of the plunger (6a) onto the axial cam profile (12e).

8. A method of synchronizing engine speed by engine speed synchronizer as claimed in claim 1, the comprising acts of:
sensing clutch pedal operation by a first sensor (6);
measuring speed of a gear box input shaft (8) by a second sensor (7);
measuring rotational speed of an engine flywheel (10) by a third sensor (9);
controlling fuel supply to engine by an electronic controller unit (ECU) (11) connected to the first sensor (6), the second sensor (7), and the third sensor (9) to synchronize rotation of an engine with rotation of the gear box input shaft (8).

9. The method as claimed in claim 8, wherein the first sensor (6) sends signals to the ECU only when the clutch pedal (4) is travelled in between 65 to 100 % with respect to clutch pedal travel.

10. The method as claimed in claim 8, fine adjustment is carried out using a worm adjuster nut (12f) configured in a cam mechanism (12) for positioning of the plunger (6a) onto the axial cam profile (12e).

Dated this 23rd day of March, 2015
P.H.D.RANGAPPA
IN/PA-1538
OF K & S PARTNERS
AGENT FOR THE APPLICANTS