WO2015145282A1 - An automated valve clearance adjustment system and a method thereof - Google Patents

Abstract

The present disclosure relates to an automated valve clearance adjustment system (100) comprising a plurality of valve clearance adjustment units (105), movably attached to a spindle holder unit (104), through at least one rotary linear actuator (104b). Each of valve clearance adjustment units (105) is provided with a plurality of spindles (105a), and each of the plurality of spindles (105a) is provisioned with a rotary actuator (105b). Each of the plurality of spindles (105a) is coupled with at least one of nut runner (105c) and a screw driver (105d) for valve clearance adjustments. A plurality of sensors (105e) is provided in each of the plurality of valve clearance adjustment units (105) to determine clearance. A control unit (109) is interfaced with all the actuators and the plurality of sensors (105e) for adjusting the valve clearance.

Description

TITLE: "AN AUTOMATED VALVE CLEARANCE ADJUSTMENT SYSTEM AND

A METHOD THEREOF"

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority from Indian Patent Application Serial No. 1531/CHE/2014, filed March 24, 2014, the contents of which are incorporated herein in their entirety.

TECHNICAL FIELD

The present disclosure generally relates to Internal Combustion (I.C) engines, particularly but not exclusively embodiments of the disclosure relate to an automated system for adjusting valve clearances of Internal Combustion (I.C) Engines.

BACKGROUND

Each cylinder of the Internal combustion engine is provided with valves such as at least one inlet valve for supplying air or air fuel mixture for combustion, and one or more exhaust valves for expelling burnt gases to atmosphere. Each of the intake and exhaust valves is operated by a cam and cam-follower mechanism so that they open and close at appropriate time intervals. The valves are operated by a rocker mechanism which converts rotary motion of the cam to linear motion of the valve. The rocker mechanism will comprise of a rocker arm carrying an adjuster screw which is pivoted to a rocker shaft. The adjuster screw will make contact with the valves for opening, and a spring provided in the valve will move the valves back to closed position. The frequent contact of the rocker arm with the valve assembly will result in wear of the adjuster screw as well as of the valve contact surface, thereby resulting in an increase in the clearance between the adjuster screw and the valve. This results in improper opening of the valve, which adversely affects the engine performance, and results in high fuel consumption. Therefore, frequent adjustment of the clearance between the adjuster screw and the valve is necessary.

Conventionally, valve clearance adjustment, also referred to as "Tappet setting" or "Valve lash setting", is done manually using a wrench, a screw-driver and a feeler gauge. For manual adjustment, adjustable screw and lock nut are fastened/unfastened using screw driver and nut wrench respectively. The feeler gauge is inserted in the gap or the clearance between adjustable screw and the valve stem, and the adjustable screw is tightened. The correct clearance setting is achieved when a slight drag is experienced on the feeler gauge. Followed by this, the lock nut is tightened using wrench. When the nut is tight, clearance is rechecked with feeler gauge and the procedure is repeated until required clearance is obtained. A major problem encountered in adjusting the valve clearance manually is the difficulty in manipulating the adjustable screw and locking nut, because of the confined space in which the mechanic must operate. In addition, there is always a tendency of applying inappropriate torque to drive the adjustable screw, which causes inaccurate clearance adjustments. Typically, the locking nut is grasped by a wrench, loosened and held in that loosened position while the screw is being adjusted, and the gap between the valve stem and screw is set using a feeler gauge. The nut must then be tightened while the screw is held fixed so the adjustment (the desired gap) does not change. This process is tedious, time-consuming and relatively inconsistent, which clearly justifies the need or the necessity for the use of automated systems to perform valve clearance adjustments.

Further, in recent past there are some developments in systems used for valve Clarence adjustment, wherein some automated systems have been developed for adjusting valve clearances which could overcome the limitations of manual system. One such system for adjusting valve clearance involves automatically turning the adjuster screw towards the valve and engaging the valve stem, and setting that position of the adjuster screw (in turn the rocker arm), as reference datum position. Thereafter, the adjuster screw is rotated and the rocker arm is set to first reference position. The angular rotation of the adjuster screw from reference datum is noted. The adjuster screw is then rotated through a predetermined angle so that rocker arm is moved to second reference position, and that position is again noted. The difference between the first and second reference positions and the predetermined angle are used to determine a coefficient, which relates the angular movement of the adjustment screw with linear movement of the rocker arm. The coefficient is then used to calculate the angular rotation of the adjustment screw required to set a predetermined valve clearance relative to the zero position. By this method, the accuracy of valve clearance setting is better in comparison with manual valve clearance setting. However, in this method, clearance adjustment is again done on a trial and error basis which is still tedious and time consuming.

In light of foregoing discussion, it is necessary to develop an improved automated system for valve clearance adjustment to overcome the limitations stated above. SUMMARY

The drawbacks of conventional valve clearance adjustments as described in the prior art are overcome and additional advantages are provided through the provision as claimed in the present disclosure.

Additional features and advantages are realized through the technicalities of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered a part of the claimed disclosure.

In one non-limiting embodiment of the present disclosure, there is provided an automated valve clearance adjustment system comprising; a supporting frame comprising a pair of pillars and a top fixture adjoining to the pair of pillars. A spindle holder unit is movably connected to the top fixture through at least one first linear actuator. A plurality of valve clearance adjustment units are movably attached to the spindle holder unit, wherein each of the plurality of valve clearance adjustment units is connected to the spindle holder unit through at least one rotary linear actuator. Further, each of the plurality of valve clearance adjustment units is provided with a plurality of spindles, and each of the plurality of spindles is provisioned with rotary actuator. Each of the plurality of spindles is configured to accommodate at least one of nut runner and a screw driver for valve clearance adjustment. A plurality of sensors is provided in each of the plurality of valve clearance adjustment units, where each of the plurality of sensors is configured to determine clearance. A control unit is interfaced with at least one first linear actuator, at least one rotary linear actuator, the rotary actuators, and the plurality of sensors for adjusting the valve clearance.

In an embodiment of the present disclosure, each of the plurality of rotary linear actuators carrying valve clearance adjustment units is slidably connected to the extending arms of the spindle holder unit. This accomplishes accurate positioning of valve clearance adjustment units onto adjuster screws and lock nuts of rocker arms for valve clearance adjustments.

In an embodiment of the present disclosure, the top fixture comprises of a plurality of guiding piston cylinders for guiding the linear movement of spindle holder unit.

In an embodiment of the present disclosure, the spindle holder unit comprises of a plurality of holder arms to grip the rocker shaft during valve clearance adjustments. In an embodiment of the present disclosure, there is provided an engine fixture unit configured to hold the engine during valve clearance adjustments. Further, the engine fixture unit is mounted on a lifter unit, which in turn is mounted on a base plate. The lifter unit comprises of at least one second linear actuator configured to linearly carry the engine fixed on the engine fixture, for valve clearance adjustment, and a plurality of shafts for guiding the linear movement of the lifter unit.

In an embodiment of the present disclosure, there is provided a second rotary actuator which is connectable to crank shaft of an engine, and is configured to move the pistons inside cylinders for valve clearance adjustment.

In another non-limiting embodiment of the present disclosure, there is provided a method to adjust valve clearances. The method comprises acts of moving a plurality of valve clearance adjustment units linearly towards valves of the engine and adjusting valve clearance through a sequence of linear and rotary movements of spindles carrying at least one nut runner and screw driver. The sequence of operations comprises acts of linearly moving the spindle to align a nut runner with a lock nut of a rocker arm and unfastening the lock nut by the rotary movement of the nut runner in first direction, aligning a screw driver with the adjuster screw of the rocker arm by linearly moving the spindle holder unit, followed by rotating the adjuster screw by the rotary movement of a screw driver, wherein the plurality of sensors sense the clearance between the adjuster screw and valve, and sends the feedback signal to stop the rotation of the adjuster screw when required clearance is achieved. Then, rotating the spindle to align the nut runner with the lock nut of the rocker arm, and fastening the lock nut by the rotary movement of the nut runner in second direction.

In an embodiment of the present disclosure, the method comprises act of moving the plurality of holder arms linearly to grip the rocker shaft. The method also comprises act of lifting the engine fixture mounted on the lifter unit and rotating the crank gear through required angle to move pistons inside cylinders for valve clearance adjustments.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The novel features and characteristics of the disclosure are set forth in the appended description. 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 illustrates the schematic front view of the automated valve clearance adjustment system according to an embodiment of the present disclosure.

Fig. 2 illustrates the perspective view of engine fixture unit mounted on the lifter unit with linear actuators and guiding shafts for lifting engine fixture unit.

Fig. 3 illustrates the crank automation unit to rotate the crank gear which moves pistons inside engine cylinders to Top Dead Centre positions. Figs. 4A and 4B illustrate the valve adjustment unit with spindles coupled to nut runners and screw drivers for adjusting lock nut and adjuster screw.

Fig. 5 illustrates valve clearance adjustment unit along with sensors involving a transmitter and a receiver to determine valve clearances.

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

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.

To overcome one or more limitations stated in the background, the present disclosure provides an automated system and a method for valve clearance adjustments in Internal Combustion Engines, such as but not limiting to four-stroke gasoline engines and diesel engines. Inlet and Exhaust valve opening in Internal Combustion (I.C) engines is brought about by a rocker arm pivoted on a rocker shaft. The first end of the rocker arm is set in oscillatory motion by a cam mounted on the cam-shaft and connected to it by a reciprocating push rod. The second end of rocker arm consists of an adjustable screw with a lock-nut to push the valve stem to bring about the opening and closing of valves. When the rotating cam reaches its peak position, the push rod pushes the first end of rocker arm pivoted about the rocker shaft, which causes the adjustable screw in second end of rocker arm to come in contact with the spring-loaded valves. This causes opening of valves against spring force. When the cam rotates further and reaches its dwell position, the valves return to initial positions under the spring force. Often, the clearance between valve stems and adjuster screws deviate from predetermined values which is detrimental to accurate valve operations i.e., valve opening and closing, adversely affecting the valve timing. This affects the normal engine operation and results in undesirable engine performance. The present disclosure provides an automated system and a method for adjusting required clearance between valves and adjuster screws. In an embodiment of the disclosure, the automated valve clearance adjustment system comprises of a plurality of valve clearance adjustment units for adjusting clearances between inlet and exhaust valves present at cylinder heads and adjuster screws of rocker arm, through fastening and unfastening processes. The valve clearance adjustment units are operated in a sequence of linear and rotary movements through rotary linear actuators, which carry these valve adjustment units. Each rotary linear actuator is linearly actuated by the linear movement of a spindle holder unit. The linear motion is necessary to move each of the valve clearance adjustment units towards inlet and exhaust valves of the engine, for valve clearance adjustment and then to retract the same after the adjustment is complete. The spindle holder unit is set into reciprocating motion (vertical upward and downward translatory motion) through at least one linear actuator. The spindle holder unit carrying rotary linear actuators which in turn carry a plurality of valve clearance adjustment units is movably connected to a top fixture. The top fixture is adjoined to a supporting frame comprising a pair of pillars so that the frame can be mounted vertically on ground on either sides of the conveyor on which the engine is placed.

Further, each of the valve clearance adjustment units comprises of rotary spindles coupled with nut runners for adjusting the lock nuts, and rotary spindles coupled with screw drivers for adjusting the adjuster screws. Furthermore, a crank automation unit forms an integral part of the automated valve clearance adjustment system, which is provided to rotate the crankshaft to move pistons inside the cylinders to TDC positions.

For valve clearance adjustments, the engine is lifted to predetermined height by a lifter unit provisioned with linear actuators for vertical movement and is also provisioned with a number of shafts for guiding the vertical movement. An engine fixture unit is mounted on the lifter unit to rigidly hold the engine and to arrest all its motion, by means of holder pins provided on it. The automated system essentially comprises of a control unit interfaced with each of the rotary actuators, linear actuators and rotary linear actuators. Sensors are provided in valve clearance adjustment units to determine the clearance between adjuster screws and valves of the engine. In an embodiment of the disclosure, the sensors are essentially transmitters and receivers, wherein the transmitter emits a suitable beam through the clearance, which is later on received by the receiver. Based on the intensity of beam in between the adjuster and valve stem, the sensors send feedback signals to rotary actuators. This is continued till required clearance is achieved, at the time of which further rotation of the adjuster screw is stopped.

The terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a setup system, device or method that comprises a list of components or steps does not include only those components or steps but may include other components or steps not expressly listed or inherent to such setup or device or method. In other words, one or more elements in a system or apparatus proceeded by "comprises... a" does not, without more constraints, preclude the existence of other elements or additional elements in the system or apparatus. Reference will now be made to the automated system for valve clearance adjustment, and is explained with the help of figures. The figures are for the purpose of illustration only and should not be construed as limitations on the arrangement. Wherever possible, referral numerals will be used to refer to the same or like parts.

Fig. 1 is an exemplary embodiment of the present disclosure which illustrates schematic front view of the automated valve clearance adjustment system. Generally, an automated valve clearance adjustment system comprises of a number of linear and rotary moving devices carrying tools for adjusting lock nuts as well as adjuster screws provided in rocker arms of I.C Engines. These rotary and linear movements are controlled by control units. Usually, in these automated systems, the engine whose valve clearances are to be adjusted is conveyed on a conveyor, which is at a predetermined height from the ground. A stopper unit is used to stop the engine at desired location on conveyor where valve clearance adjustments are made. Thereafter, the engine is lifted and all its motions are arrested to initiate the process of valve clearance adjustment.

As shown in Fig. 1, the automated valve clearance adjustment system (100) comprises a support frame (101) with a pair of pillars (101a and 101b) rigidly mounted on ground. The pair of pillars (101a and 101b) are adjoined by a beam (101c) to which the top fixture unit (102) is fixed. In an embodiment of the present disclosure the top fixture unit (102) is fixed to the beam (101c) by processes such as but not limiting to a welding process or a fastening process. The top fixture unit (102) has provisions to accommodate at least one first linear actuator (103 a) and a plurality of guiding piston cylinders (103b). In an embodiment of the present disclosure the first linear actuator (103a) is at least one of a pneumatic actuator and the hydraulic actuator. Further, each of the at least one first linear actuators (103a) and each of the plurality of guiding piston cylinders (103b) carry a spindle holder unit (104) linearly and is configured to move vertically upwards and downwards by means of at least one first linear actuator (103 a) and guided by a plurality of guiding piston cylinders (103b). The spindle holder unit (104) is configured to accommodate a plurality of holder arms (104a) to grip the rocker shaft during valve clearance adjustment so as to minimize the vibration of the rocker shaft. In an embodiment of the present disclosure the plurality of holder arms (104a) are either permanently fixed to the spindle holder unit (104) by processes such as but not limiting to welding or removably fixed through fastening. Furthermore, a plurality of valve clearance adjustment units (105) are movably attached to the spindle holder unit (104), wherein each of the plurality of valve clearance adjustment units (105) is connected to the spindle holder unit (104) through at least one rotary linear actuator (104b). In an embodiment of the present disclosure the rotary linear actuator (104b) is at least one of a pneumatic rotary linear actuator, and a hydraulic actuator. Each of the at least one rotary linear actuator (104b) imparts a linear movement i.e. vertical downward movement to each of the plurality of valve clearance adjustment units (105) to reach the rocker arm of the engine to perform valve clearance adjustments, and a vertical upward movement to retract each of the plurality of valve clearance adjustment units (105) after adjustment is complete. Similarly, each of the at least one rotary linear actuator (104b) rotates each of the plurality of valve clearance adjustment units (105) to align plurality of spindles (105a) with lock nuts (110) and adjuster screws (120) of the rocker arm for valve clearance adjustment. In an embodiment of the present disclosure, each of the plurality of rotary linear actuators (104b) is configured to slide on extended arms of the spindle holder unit (104) by means of actuators, such as but not limiting to hydraulic and pneumatic actuators. This sliding movement of each of the plurality of rotary linear actuators (104b) enables each of the valve clearance adjustment units (105) to be positioned accurately over adjuster screws (120) and lock nuts (110) of rocker arms. Further, each of the plurality of valve clearance adjustment units (105) is provisioned with a plurality of spindles (105a) driven by a plurality of first rotary actuators (105b), wherein each of the plurality of spindles (105a) is configured to accommodate at least one nut runner (105c) and at least one screw driver (105d). In an embodiment of the present disclosure the plurality of first rotary actuators (105b) includes but not limiting to pneumatic rotary actuators, hydraulic rotary actuators and a motor. In an embodiment of the present disclosure the nut runner (105c) includes but not limiting to a wrench, ratchet and spanner. Initially, each of the plurality of valve clearance adjustment units (105) is linearly moved closer to adjuster screws (120) and lock nuts (110) of rocker arm. This is done by the linear movement of each of the plurality of rotary linear actuator (104b). Then, each of the plurality of spindles (105a) to which at least one nut runner (105c) is removably connected, is aligned with lock nut (110) of the rocker arm. Each of the plurality of spindles (105a) is then rotated in first direction by each of the plurality of first rotary actuators (105b) provided in valve clearance adjustment unit (105), to unfasten lock nut (110) of the rocker arm. Once the unfastening of lock nut (110) is complete, each of the plurality of valve clearance adjustment units (105) retracts upwards and rotates through a predetermined angle. This is to align at least one screw driver (105d) removably connected to each of the plurality of spindles (105a) with adjuster screws (120) of rocker arm. Thereafter, each of valve clearance adjustment units (105) is moved vertically downwards towards the valves so that each of the spindles (105a) with at least one screw driver (105d) is rotated by each of the plurality of first rotary actuators (105b) to adjust the adjuster screw (120). The adjuster screw (120) is adjusted until desired clearance between the adjuster screw (120) and valve stem is achieved. Once the adjustment of adjuster screw (120) is complete, each of the plurality of valve clearance adjustment units (105) retracts upwards. Followed by the upward retraction, each of the plurality of valve clearance adjustment units (105) rotates so that at least one nut runner (105c) is aligned with lock nut (110) of the rocker arm. This is followed by linearly moving each of the plurality of valve clearance adjustment unit (105) towards rocker arm. Lastly, each of the plurality of spindles (105a) to which at least one nut runner (105c) is removably connected, is rotated in second direction to fasten the lock nut (110) and to lock the adjuster screw (120) in set position. A plurality of sensors (105e) are provisioned on each of the plurality of valve clearance adjustment units (105), wherein the plurality of sensors (105e) is configured to determine clearance during valve clearance adjustments. In an embodiment of the present disclosure the plurality of sensors (105e) includes but not limiting to a light sensor. In one embodiment the at least one nut runner (105c) is removably connected to each of the plurality of spindles (105a). The phrase "removably connected" in this context refers to detachable arrangement. Depending on the requirement one can either remove or connect.

The control unit controls the operation of the spindles (105a). This in-turn controls the operation of the at least one screw driver (105d) and at least one nut runner (105c). The control unit receives feedback from the sensors about the adjuster screw (120) position. Based on the feedback the control unit operates the screw driver (105d) to adjust the adjuster screw (120). When the desired position is reached by the adjuster screw (120), the control unit stops the rotation of spindle (105a) carrying the screw driver (105d). The control unit also controls the operation of plurality of rotary linear actuators (104b), at least one first linear actuator (103a) and plurality of rotary actuators (105b). Fig. 2 illustrates the perspective view of engine fixture unit (106) mounted on the lifter unit (107). The lifter unit (107) comprises of at least one second linear actuator (107a) and a plurality of guiding shafts (107b) for lifting engine fixture unit (106) to a predetermined height. In an embodiment of the present disclosure the second linear actuator (107a) includes but not limiting to pneumatic linear actuator and hydraulic linear actuator. The engine fixture unit (106) comprises of a plurality of holder pins (106a) to hold the engine so as to arrest the motion of engine in all the directions except vertical motion. Further, the engine fixture unit (106) comprises of provision for the lifter unit (107) to make contact with it. In an embodiment of the present disclosure the provision includes but not limiting to dowel holes. Similarly, the lifter unit (107) comprises of a plurality of pins to hold the engine fixture unit (106). In one embodiment of the present disclosure the plurality of pins include but not limiting to dowel pins.

Fig. 3 illustrates the crank automation unit (108) to rotate the crank gear of the engine which moves pistons inside engine cylinders to TDC positions. The crank automation unit (108) comprises a spindle (108a) to rotate the crank gear through required angle to move the pistons inside cylinders to TDC positions so that the inlet and exhaust valves are completely closed, during which valve clearance adjustments are made. Usually, the crank gear is rotated through an angle of 180° from its initial position (beginning of cycle) which moves selected number of pistons in their respective cylinders to TDC positions, at the time of which the valve clearance adjustments are made. Thereafter, the crank gear is further rotated through 180° to move all the other pistons to TDC positions to perform valve clearance adjustments. The spindle (108a) of crank automation unit (108) is driven by a suitable driving mechanism such as but not limiting to timer belt and gear arrangement and powered by a suitable power source such as but not limiting to an electric motor. The entire crank automation unit (108) is interfaced with the control unit (109), where the control unit (109) accurately controls the timing of crank gear rotation and ensures proper positioning of pistons inside cylinders for clearance adjustments to be made. Figs. 4A and 4B illustrate the valve clearance adjustment units (105) comprising a plurality of spindles (105a) and each of the plurality of spindles (105a) is imparted with rotary movement by means of rotary actuators (105b). At least one nut runner (105c) is removably connected to each of the plurality of spindles (105a) to perform unfastening and fastening operations of the lock nut (110) provided in rocker arm. Similarly, at least one screw driver (105d) is removably connected to each of the plurality of spindles (105a) to perform unfastening and fastening operations of adjuster screw (120) provided in the rocker arm. Further, nut runners (105c) and screw drivers (105d) are removably connected to plurality of spindles (105a) by suitable means, such as but not limiting to a coupling joint. Fig. 5 illustrates inlet and exhaust valve adjustment units provided with sensors (105e) to determine clearance between adjuster screw (120) and valve stem, when the adjuster screw (120) is being manipulated. In an embodiment of the present disclosure the sensors (105e) include but not limiting to light sensors. The sensor (105e) essentially comprises of a transmitter (105f) to emit a suitable beam such as but not limiting to a laser beam. The beam emitted by the transmitter (105f) is made to pass through the clearance between adjuster screw (120) and valve stem, which is later on received by the receiver (105g). As shown in fig. 5, the transmitter-receiver (105f and 105g) pair is provided on the sensor holder arms of the valve clearance adjustment unit. The intensity of beam emitted by the transmitter (105f) varies depending on the clearance or the gap between the adjuster screw (120) and valve stem. This variation in intensity is detected by the receiver (105g) which sends a feedback signal to terminate further rotation of the adjuster screw (120) when required clearance is achieved. The automated system for valve clearance adjustment of the present disclosure has following advantages:

The present disclosure provides an automated valve clearance adjustment system which precisely and automatically adjusts the adjuster screw and lock nut without any manual intervention.

The present disclosure provides an automated system for valve clearance adjustment which is essentially an integration of electronic and mechanical components interfaced with control systems which automatically performs all the operations associated with valve clearance adjustments. This automated system is highly accurate, reliable and time-saving over the conventional manual valve clearance adjustment operations.

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.

TABLE OF REFERRAL NUMERALS

Referral Numerals Description

100 Automated valve clearance adjustment

system

101 Supporting frame

101a and 101b Pair of pillars

101c Beam

102 Top fixture

103a First linear actuator

103b Guiding piston cylinders

104 Spindle holder unit

104a Holder arms

104b Rotary linear actuators

105 Valve clearance adjustment units

105a Spindles of valve adjustment units

105b First Rotary actuator

105c Nut runners

105d Screw drivers

105e Sensors

105f Transmitter

105g Receiver

106 Engine fixture

106a Holder pins

107 Lifter unit

107a Second linear actuator

107b Guiding shafts 108 Crank automation unit

108a Second rotary actuator

109 Control unit

110 Lock nut

120 Adjuster screw

Claims

We Claim:

1. An automated valve clearance adjustment system (100), the system (100) comprising: a support frame (101) comprising a pair of pillars (101a and 101b), and a top fixture (102) adjoining the pair of pillars (101a and 101b);

a spindle holder unit (104) movably connected to the top fixture (102) through at least one first linear actuator (103a);

a plurality of valve clearance adjustment units (105) movably attached to the spindle holder unit (104), wherein each of the plurality of valve clearance adjustment units (105) is connected to the spindle holder unit (104) through at least one rotary linear actuator (104b); a plurality of spindles (105a) provided in each of the plurality of valve clearance adjustment units (105), wherein each of the plurality of spindles (105a) is provisioned with first rotary actuators (105b),

wherein, each of the plurality of spindles (105a) is configured to accommodate at least one of nut runner (105c) and a screw driver (105d) for valve clearance adjustment;

a plurality of sensors (105e) provisioned on the plurality of valve clearance adjustment units (105), wherein the plurality of sensors (105e) are configured to determine clearance; and

a control unit (109) interfaced with at least one first linear actuator (103a), at least one rotary linear actuator (104b), the rotary actuators (105b), and the plurality of sensors (105e) for adjusting the valve clearance.

2. The system as claimed in claim 1, wherein the top fixture (102) comprises of a plurality of guiding piston cylinders (103b) for guiding the linear movement of spindle holder unit (104).

3. The system as claimed in claim 1, wherein the spindle holder unit (104) comprises of a plurality of holder arms (104a) to grip the rocker shaft during valve clearance adjustments.

4. The system as claimed in claim 1 comprises of a lifter unit (107) mounted on a base plate.

5. The system as claimed in claim 4, wherein the lifter unit (107) comprises of an engine fixture unit (106) configured to hold the engine during valve clearance.

6. The system as claimed in claim 5, wherein the lifter unit (107) comprises at least one second linear actuator (107a) configured to carry the engine fixed on the engine fixture (106) linearly for valve clearance adjustment.

7. The system as claimed in claim 1, wherein the lifter unit (107) comprises of a plurality of shafts (107b) for guiding the linear movement of the lifter unit (107).

8. The system as claimed in claim 1 comprises a second rotary actuator (108a) connectable to crankshaft of an engine.

9. The system as claimed in claim 8, wherein the second rotary actuator (108a) is configured to rotate the crank to move the pistons inside the cylinder for valve clearance adjustment.

10. A method for valve clearance adjustment, the method comprising acts of:

moving a plurality of valve clearance adjustment units (105) linearly towards valves of the engine;

adjusting valve clearance through a sequence of linear and rotary movements of spindles (104b and 105a) carrying at least one nut runner (105c) and screw driver (105d), wherein the sequence of operations comprises acts of;

linearly moving the rotary linear actuator (104b) to align a nut runner

(105c) with a lock nut (110) of a rocker arm and unfastening the lock nut (110) by the rotary movement of the nut runner (105c) in first direction;

aligning a screw driver (105d) with the adjuster screw (120) fastened to the lock nut (110) of the rocker arm by linearly moving the spindle holder unit (104);

rotating the adjuster screw (120) by the rotary movement of a screw driver (105d), wherein the plurality of sensors (105e) sense the clearance between the adjuster screw (120) and valve, and sends the feedback signal to stop the rotation of the adjuster screw (120) when required clearance is achieved;

rotating the spindle (104b) to align the nut runner (105c) with the lock nut (110) of the rocker arm, and fastening the lock nut (110) by the rotary movement of the nut runner (105c) in second direction.

11. The method according to claim 10 comprises act of moving the plurality of holder arms (104a) linearly to grip the rocker shaft.

12. The method according to claim 10 comprises act of lifting the engine fixture (106) mounted on the lifter unit (107), for valve clearance adjustments.

13. The method according to claim 10 comprises act of rotating the crank gear through required angle to move pistons inside the cylinders, for valve clearance adjustments.