CN214170642U - Engine timing mechanism and engine - Google Patents

Abstract

The utility model discloses an engine timing mechanism and engine. The engine timing mechanism comprises an engine cylinder cover, a timing chain, a crankshaft chain wheel, two camshaft chain wheels and a chain fixed guide rail; the timing chain is used for connecting the crankshaft chain wheel and the two camshaft chain wheels; the chain fixed guide rail is detachably connected with the engine cylinder cover and used for guiding the transmission direction of the timing chain; a timing convex rib is arranged on one surface of the chain fixed guide rail opposite to the engine cylinder cover; the engine cylinder lid is equipped with timing groove array with the relative one side of chain fixed guide rail, and timing groove array includes two at least timing grooves of arranging in parallel along the adjustment direction in right time, and the groove in right time matches with the protruding muscle in right time. The engine timing mechanism adjusts the relative position of the chain fixed guide rail and the engine cylinder cover through the matching of the timing convex rib and the timing groove array, compensates the timing phase error of the engine, and ensures the accuracy and the consistency of the engine timing phase of the engine.

Description

Engine timing mechanism and engine

Technical Field

The utility model relates to an engine distribution technical field especially relates to an engine timing mechanism and engine.

Background

The timing mechanism of the engine is an important component of an engine gas distribution system, and the accuracy of air inlet time and exhaust time is ensured by being connected with a crankshaft and matched with a certain transmission ratio. With the development of engine technology, the requirements on the precision and consistency of the timing phase of the engine are higher and higher, the timing phase of the engine is an important reference standard for the calibration of the development performance of the engine, and calibration parameters such as ignition and oil injection of the engine can be directly determined; if the timing phase of the engine is inaccurate or the consistency is poor, the setting of calibration parameters such as ignition and oil injection of the engine is inaccurate or uncertain, and the efficiency and quality of calibration work are influenced.

The existing engine timing mechanism generally comprises a crankshaft sprocket, a camshaft sprocket, a timing chain sleeved on the crankshaft sprocket and the camshaft sprocket, a chain movable guide rail with a timing tensioner and a chain fixed guide rail which is fixed after assembly, and the timing tensioner on the chain movable guide rail is used for timing adjustment. Due to manufacturing errors or design gaps among parts, after the engine is assembled, the timing phase of the engine has a large error with a theoretical design value, and the smooth operation of calibration parameters such as ignition and oil injection of the subsequent engine is influenced; and when the actual performance of the engine has abnormal deviation, the operation of the abnormal checking and processing process is inconvenient, and the processing efficiency is influenced.

SUMMERY OF THE UTILITY MODEL

The embodiment of the utility model provides an engine timing mechanism and engine to solve current engine timing mechanism assembly back, still have the relatively poor problem of engine timing phase precision and uniformity.

The utility model provides an engine timing mechanism, which comprises an engine cylinder cover, a timing chain, a crankshaft sprocket, two camshaft sprockets and a chain fixed guide rail; the timing chain is used for connecting the crankshaft chain wheel and the two camshaft chain wheels; the chain fixed guide rail is detachably connected with the engine cylinder cover and used for guiding the transmission direction of the timing chain; a timing convex rib is arranged on one surface of the chain fixed guide rail opposite to the engine cylinder cover; the engine cylinder cover and the opposite side of the chain fixed guide rail are provided with a timing groove array, the timing groove array comprises at least two timing grooves which are arranged in parallel along a timing adjusting direction, and the timing grooves are matched with the timing convex ribs.

Preferably, the engine cylinder cover comprises a cylinder cover body and a cylinder cover limiting part extending from the edge of the cylinder cover body, and a cylinder cover connecting hole is formed in the cylinder cover body; the timing groove array is positioned between the cylinder cover connecting hole and the cylinder cover limiting part;

the chain fixed guide rail comprises a guide rail connecting part and a guide rail limiting part extending from the edge of the guide rail connecting part, a guide rail connecting hole is formed in the guide rail connecting part, and the timing convex rib is positioned between the guide rail connecting hole and the guide rail limiting part;

the engine timing mechanism further comprises a bolt and nut assembly for being assembled in the cylinder cover connecting hole and the guide rail connecting hole.

Preferably, the inner wall of the guide rail limiting part is positioned inside an outer common tangent of the crankshaft sprocket and the camshaft sprocket; a first gap for accommodating the timing chain is formed between one tail end of the guide rail limiting part and the camshaft chain wheel, and a second gap for accommodating the timing chain is formed between the other tail end of the guide rail limiting part and the crankshaft chain wheel.

Preferably, an adjusting displacement space matched with the timing adjusting direction is formed in the guide rail connecting hole, and the adjusting displacement space is perpendicular to the timing convex rib.

Preferably, the guide rail connecting hole is a runway-shaped hole, the runway-shaped hole comprises a rectangular area and two tangent semicircular areas extending from the short side direction of the rectangular area, and the displacement adjusting space is the rectangular area.

Preferably, a displacement extension gap is arranged at one tail end of the chain fixed guide rail, which is close to the camshaft chain wheel.

Preferably, the timing rib is a triangular rib, and the timing groove is a triangular groove.

Preferably, the number of the timing ribs is at least one, and the number of the timing grooves is greater than the number of the timing ribs.

Preferably, the timing groove array has a width of 3mm to 5 mm.

The utility model also provides an engine, which comprises a crankshaft and two camshafts, and comprises the engine timing mechanism, wherein the crankshaft chain wheel is assembled on the crankshaft; the camshaft sprocket is assembled on the camshaft.

The embodiment of the utility model provides an engine timing mechanism and engine, set up the protruding muscle in right time on the guide rail is decided to the chain, set up on the engine cylinder lid with protruding muscle complex in right time groove array, the groove array in right time includes two at least timing grooves of arranging along the timing adjustment direction in parallel, cooperation through protruding muscle in right time and groove array in right time, the relative position of guide rail and engine cylinder lid is decided to the adjustment chain, compensate engine timing phase error, guarantee engine timing phase precision and the uniformity of engine, eliminate the difficulty that engine timing phase error brought for the calibration work of calibration parameter, help reducing the uncertain factor of unusual problem investigation in the engine development process, thereby improve engine development quality and shorten development cycle; and the relative position is adjusted through the matching of the timing convex rib and the timing groove array, so that the adjustment flexibility is guaranteed, and the positioning and fixing reliability can be ensured.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required to be used in the description of the embodiments of the present invention will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without inventive labor.

Fig. 1 is a schematic diagram of an engine timing mechanism according to an embodiment of the present invention;

fig. 2 is a schematic view of an engine head according to an embodiment of the present invention;

fig. 3 is a schematic view of the chain guide rail according to an embodiment of the present invention.

In the figure: 11. an engine cylinder head; 111. a cylinder head body; 112. a cylinder cover limiting part; 113. a cylinder cover connecting hole; 12. a timing chain; 13. a crankshaft sprocket; 14. a camshaft sprocket; 15. a chain fixed guide rail; 151. A guide rail connecting portion; 152. a guide rail limiting part; 153. a guide rail connecting hole; 154. shifting to prolong the gap; 16. A timing convex rib; 17. a timing groove.

Detailed Description

In order to make the technical problem, technical solution and advantageous effects solved by the present invention more clearly understood, the following description is given in conjunction with the accompanying drawings and embodiments to further explain the present invention in detail. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

In the description of the present invention, it is to be understood that the terms "longitudinal", "radial", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, and are used merely for convenience of description and to simplify the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the present invention. In the description of the present invention, "a plurality" means two or more unless otherwise specified.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.

The utility model provides an engine timing mechanism, as shown in figures 1-3, the engine timing mechanism comprises an engine cylinder cover 11, a timing chain 12, a crankshaft sprocket 13, two camshaft sprockets 14 and a chain fixed guide rail 15; the timing chain 12 is used for connecting a crankshaft sprocket 13 and two camshaft sprockets 14; the chain fixed guide rail 15 is detachably connected with the engine cylinder cover 11 and used for guiding the transmission direction of the timing chain 12; a timing convex rib 16 is arranged on one surface of the chain fixed guide rail 15 opposite to the engine cylinder cover 11; the opposite side of engine cylinder lid 11 and chain fixed guide 15 is equipped with the recess array of timing, and the recess array of timing includes two at least timing recesses 17 that arrange along the timing adjustment direction in parallel, and timing recess 17 and timing convex rib 16 phase-match.

In this example, the timing chain 12 is mounted on a crankshaft sprocket 13 and two camshaft sprockets 14 for connecting the crankshaft sprocket 13 and the two camshaft sprockets 14 so that the crankshaft sprocket 13 and the two camshaft sprockets 14 are driven by the timing chain 12. The chain fixed guide rail 15 is detachably connected with the engine cylinder cover 11, and specifically, the chain fixed guide rail can be detachably connected through a bolt and nut assembly and used for guiding the transmission direction of the timing chain 12.

As an improvement of the prior art, a timing rib 16 is provided on a surface of the chain fixed rail 15 facing the engine head 11, and the timing rib 16 is a rib provided on the chain fixed rail 15 for realizing timing adjustment. Correspondingly, the opposite side of the engine cylinder cover 11 and the chain fixed guide rail 15 is provided with a timing groove array, the timing groove array comprises at least two timing grooves 17 which are arranged in parallel along the timing adjusting direction, and the timing grooves 17 are matched with the timing convex ribs 16. The timing groove 17 is a groove provided on the chain guide 15 for achieving timing adjustment. The timing adjustment direction is understood to be a direction for adjusting the movement of the chain guide 15 relative to the engine head 11 during timing adjustment.

As an example, in the engine timing mechanism assembling process, in the first assembling process, the timing bead 16 of the chain guide 15 is assembled on the outermost timing groove 17 of the timing groove array of the engine head 11, and the first assembling is completed. After the engine timing mechanism is completely assembled, measuring the timing phase error of the engine, adjusting the relative position between the chain fixed guide rail 15 and the engine cylinder cover 11 along the timing adjustment direction according to the measured timing phase error of the engine, clamping a timing groove 17 into the timing convex rib 16 from outside to inside at each time, measuring the timing phase error of the engine again, repeating the steps until the accurate timing phase of the engine is obtained, completing calibration work of calibration parameters of ignition, oil injection and the like of the engine, and finally fixing the chain fixed guide rail 15 on the engine cylinder cover 11 by adopting a bolt-nut assembly to complete the assembly of the engine timing mechanism. The bolt-nut assembly is an assembly for fixing the engine cylinder head 11 and the chain fixed guide rail 15, and comprises a fastening bolt and a fastening nut matched with the fastening bolt.

In the engine timing mechanism provided by the embodiment, the timing convex rib 16 is arranged on the chain fixed guide rail 15, the timing groove array matched with the timing convex rib 16 is arranged on the engine cylinder cover 11, the timing groove array comprises at least two timing grooves 17 which are arranged in parallel along the timing adjustment direction, and the relative position of the chain fixed guide rail 15 and the engine cylinder cover 11 is adjusted through the matching of the timing convex rib 16 and the timing groove array, so that the timing phase error of the engine is compensated, the accuracy and the consistency of the engine timing phase of the engine are ensured, the difficulty brought to the calibration work of calibration parameters by the timing phase error of the engine is eliminated, the uncertain factors of abnormal problem investigation in the engine development process are reduced, the engine development quality is improved, and the development period is shortened; moreover, the relative position is adjusted through the matching of the timing convex rib 16 and the timing groove array, and the positioning and fixing reliability can be ensured while the adjustment flexibility is ensured.

In an embodiment, the engine cylinder head 11 includes a cylinder head body 111 and a cylinder head limiting portion 112 extending from an edge of the cylinder head body 111, and a cylinder head connection hole 113 is formed on the cylinder head body 111; the timing groove array is positioned between the cylinder cover connecting hole 113 and the cylinder cover limiting part 112; the chain fixed guide rail 15 comprises a guide rail connecting part 151 and a guide rail limiting part 152 extending out of the edge of the guide rail connecting part 151, a guide rail connecting hole 153 is formed in the guide rail connecting part 151, and the timing convex rib 16 is located between the guide rail connecting hole 153 and the guide rail limiting part 152; the engine timing mechanism further includes a bolt and nut assembly for fitting within the head attachment bore 113 and the rail attachment bore 153.

As shown in fig. 2, the engine head 11 includes a head body 111 and a head-limiting portion 112 extending from an edge of the head body 111, in this example, the head body 111 and the head-limiting portion 112 are designed in an L shape to define an installation position of the chain guide 15. The cylinder cover body 111 is provided with a cylinder cover connecting hole 113, the cylinder cover connecting hole 113 is a connecting hole which is arranged on the cylinder cover body 111 and is used for assembling a bolt-nut assembly, the bolt-nut assembly is an assembly for fixing the engine cylinder cover 11 and the chain fixed guide rail 15, and the bolt-nut assembly comprises a fastening bolt and a fastening nut matched with the fastening bolt. In this example, the timing groove array is specifically provided between the head connection hole 113 and the head restraint portion 112. As an example, the head connection hole 113 may be a circular hole.

As shown in fig. 3, the chain guide 15 includes a guide connecting portion 151 and a guide limiting portion 152 extending from an edge of the guide connecting portion 151, in this example, the guide connecting portion 151 and the guide limiting portion 152 are L-shaped for guiding the transmission direction of the timing chain 12. Understandably, the timing chain 12 assembled on the crankshaft sprocket 13 and the two camshaft sprockets 14 contacts the guide rail limiting part 152 during the transmission process, and transmits along the inner wall direction of the guide rail limiting part 152, so as to achieve the purpose of guiding the transmission direction of the timing chain 12 by the chain fixed guide rail 15. The rail coupling portion 151 is provided with a rail coupling hole 153, and the rail coupling hole 153 is a coupling hole for assembling a bolt and nut assembly provided on the chain fixing rail 15. In this example, the timing bead 16 is specifically provided between the rail connection hole 153 and the rail stopper 152.

In this example, the engine timing mechanism further includes a bolt-and-nut assembly for fitting in the cylinder head coupling hole 113 and the rail coupling hole 153, and after the engine timing phase adjustment is completed by the timing bead 16 of the chain fixing rail 15 and the timing groove array of the engine cylinder head 11, the fastening bolts of the bolt-and-nut assembly are fitted in the cylinder head coupling hole 113 and the rail coupling hole 153, and are tightened with the fastening nuts, so as to achieve the purpose of fixing the engine cylinder head 11 and the chain fixing rail 15.

In one embodiment, the inner wall of the guide rail limiting portion 152 is located inside the outer common tangent of the crankshaft sprocket 13 and a camshaft sprocket 14; a first gap for accommodating the timing chain 12 is formed between one end of the guide rail limiting portion 152 and the camshaft sprocket 14, and a second gap for accommodating the timing chain 12 is formed between the other end thereof and the crankshaft sprocket 13.

In this example, the chain fixing rail 15 is fitted on one side of the external common tangent of the crankshaft sprocket 13 and a camshaft sprocket 14, and the inner wall of the rail stopper portion 152 is located inside the external common tangent of the crankshaft sprocket 13 and a camshaft sprocket 14, so that the timing chain 12 between the crankshaft sprocket 13 and the corresponding camshaft sprocket 14 is in contact with the inner wall of the rail stopper portion 152; in addition, a first gap for accommodating the timing chain 12 is formed between one end of the guide rail limiting part 152 and the camshaft sprocket 14, and a second gap for accommodating the timing chain 12 is formed between the other end of the guide rail limiting part 152 and the crankshaft sprocket 13, so that the transmission direction of the timing chain 12 is guided by the guide rail limiting part 152 to deviate towards the inner side of the outer common tangent line, the timing phase compensation of the engine is realized, the accuracy and the consistency of the engine timing phase of the engine are guaranteed, the difficulty brought by the calibration work of calibration parameters due to the error of the engine timing phase is eliminated, the uncertain factors for checking abnormal problems in the engine development process are reduced, and the development quality of the engine is improved and the development period is shortened.

In one embodiment, an adjustment displacement space with a timing adjustment direction matching is formed in the rail connection hole 153.

In this example, an adjustment displacement space, which matches the timing adjustment direction, is formed in the rail connection hole 153, and this adjustment displacement space is a space for the fastening bolt of the bolt-nut assembly to move in the timing adjustment direction. In this example, the long side direction of the adjustment displacement space is equal to the timing adjustment direction and perpendicular to the timing convex rib 16, and in the process of engine timing phase compensation, after the accurate positioning of the phase adjustment is performed through the timing convex rib 16 and the timing groove array, the relative position of the fastening bolt in the long side direction of the adjustment displacement space is correspondingly adjusted, and then the fastening nut is screwed, so that the fixation of the chain fixed guide rail 15 and the engine cylinder cover 11 is realized, and the assembly of the engine timing mechanism is completed.

As an example, the guide rail connection hole 153 may be a rectangular hole, which is formed with an adjustment displacement space, so that after the fastening bolt assembled in the rectangular hole is precisely positioned for phase adjustment through the timing convex rib 16 and the timing groove array, the relative position of the fastening bolt in the long side direction of the adjustment displacement space formed by the rectangular hole is correspondingly adjusted, and then the fastening nut is tightened, so as to fix the chain fixed guide rail 15 and the engine cylinder head 11, and complete the assembly of the engine timing mechanism.

As an example, the guide rail connection hole 153 may be a track-shaped hole, the track-shaped hole includes a rectangular area and two semicircular areas extending from a short side direction of the rectangular area, and the adjustment displacement space includes the rectangular area. In this example, an adjustment displacement space is formed in the runway-shaped hole, so that the fastening bolt assembled in the runway-shaped hole is correspondingly adjusted in the relative position in the long side direction of the adjustment displacement space formed in the runway-shaped hole after the accurate positioning of the phase adjustment is performed through the timing convex rib 16 and the timing groove 17, and then the fastening nut is screwed down, so that the fixation of the chain fixed guide rail 15 and the engine cylinder cover 11 is realized, and the assembly of the engine timing mechanism is completed.

In one embodiment, as shown in FIG. 1, a shifted extension gap 154 is provided on an end of the chain guide 15 near the camshaft sprocket 14.

In this example, a displacement extension gap 154 is provided at a terminal of the chain fixed guide 15 close to the camshaft sprocket 14, specifically, a displacement extension gap 154 is provided at a terminal of the guide limiting portion 152 close to the camshaft sprocket 14, so that the chain fixed guide 15 can move smoothly between the chain fixed guide 15 and the timing chain 12 within the timing adjustment range when moving along the timing adjustment direction relative to the engine cylinder head 11.

In one embodiment, the timing rib 16 is a triangular rib and the timing groove 17 is a triangular groove.

In this example, the timing convex rib 16 is designed as a triangular convex rib, and the timing groove 17 is designed as a triangular groove, so that the timing adjustment operation is more convenient compared with a rectangular or arc design, an accurate adjustment scale can be formed, the timing phase compensation of the engine can be realized quickly, the one-time adjustment in place can be realized, repeated operation of multiple times of adjustment and measurement can be avoided, and the processing efficiency of processing the timing phase compensation of the engine can be improved.

In one embodiment, the number of timing ribs 16 is at least one, and the number of timing grooves 17 is greater than the number of timing ribs 16.

In this example, the number of the timing ribs 16 may be at least one, that is, a single one, or at least two parallel arranged in the timing adjustment direction, so that at least one timing rib 16 may be inserted into the timing groove 17 having the same number as the timing ribs 16 during the timing adjustment process, thereby ensuring the adjustment flexibility and the positioning and fixing reliability. Understandably, the reliability of the movement of at least one timing rib 16 along the timing adjustment direction can be ensured only if the number of the timing grooves 17 is greater than that of the timing ribs 16; the matching process of one timing convex rib 16 and at least two timing grooves 17 in the timing groove array is simpler and more convenient; the process of matching the at least two timing ribs 16 with the at least two timing grooves 17 in the timing groove array further contributes to securing the reliability of positioning and fixing.

In one embodiment, the timing groove array has a width of 3mm to 5 mm. In this example, the width of the timing groove array refers to the distance of at least two timing grooves 17 arranged in parallel in the timing adjustment direction, and may be understood as the timing adjustment range.

The present embodiment also provides an engine comprising a crankshaft and two camshafts, and further comprising the engine timing mechanism in the above embodiment, the crankshaft sprocket 13 is assembled on the crankshaft; the camshaft sprocket 14 is assembled to the camshaft.

Generally, an engine includes an engine head 11 and at least two cylinders disposed in the engine head 11, a crankshaft is disposed between the two cylinders, and a camshaft is disposed on each of an intake valve and an exhaust valve near the cylinders, that is, the engine includes two camshafts, an intake camshaft and an exhaust camshaft, respectively.

In this example, the engine timing mechanism includes an engine head 11, a timing chain 12, a crankshaft sprocket 13, two camshaft sprockets 14, and a chain fixed guide 15. Wherein, the crankshaft sprocket 13 is assembled on the crankshaft, which means that the crankshaft sprocket 13 and the crankshaft are coaxially arranged and fixedly connected. The camshaft sprocket 14 is assembled on the camshaft, which means that the camshaft sprocket 14 and the camshaft are coaxially arranged and fixedly connected. Understandably, the two camshaft sprockets 14 are respectively assembled on the two camshafts, i.e., the two camshaft sprockets 14 include an intake camshaft sprocket 14 assembled on the intake camshaft and an exhaust camshaft sprocket 14 assembled on the exhaust camshaft.

As an improvement of the prior art, a timing rib 16 is provided on a surface of the chain fixed rail 15 facing the engine head 11, and the timing rib 16 is a rib provided on the chain fixed rail 15 for realizing timing adjustment. Correspondingly, the opposite side of the engine cylinder cover 11 and the chain fixed guide rail 15 is provided with a timing groove array, the timing groove array comprises at least two timing grooves 17 which are arranged in parallel along the timing adjusting direction, and the timing grooves 17 are matched with the timing convex ribs 16. The timing groove 17 is a groove provided on the chain guide 15 for achieving timing adjustment. The timing adjustment direction is understood to be a direction for adjusting the movement of the chain guide 15 relative to the engine head 11 during timing adjustment.

In the engine provided by the embodiment, the timing convex rib 16 is arranged on the chain fixed guide rail 15, the timing groove array matched with the timing convex rib 16 is arranged on the engine cylinder cover 11, the timing groove array comprises at least two timing grooves 17 which are arranged in parallel along the timing adjusting direction, and the relative position of the chain fixed guide rail 15 and the engine cylinder cover 11 is adjusted through the matching of the timing convex rib 16 and the timing groove array, so that the timing phase error of the engine is compensated, the accuracy and the consistency of the engine timing phase of the engine are ensured, the difficulty brought to the calibration work of calibration parameters by the timing phase error of the engine is eliminated, the uncertain factors of abnormal problem investigation in the engine development process are reduced, the development quality of the engine is improved, and the development period is shortened; moreover, the relative position is adjusted through the matching of the timing convex rib 16 and the timing groove array, and the positioning and fixing reliability can be ensured while the adjustment flexibility is ensured.

The above-mentioned embodiments are only used for illustrating the technical solution of the present invention, and not for limiting the same; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not substantially depart from the spirit and scope of the embodiments of the present invention, and are intended to be included within the scope of the present invention.

Claims (10)

1. An engine timing mechanism comprises an engine cylinder cover, a timing chain, a crankshaft chain wheel, two camshaft chain wheels and a chain fixed guide rail; the timing chain is used for connecting the crankshaft chain wheel and the two camshaft chain wheels; the chain fixed guide rail is detachably connected with the engine cylinder cover and used for guiding the transmission direction of the timing chain; the timing mechanism is characterized in that a timing convex rib is arranged on one surface of the chain fixed guide rail, which is opposite to the engine cylinder cover; the engine cylinder cover and the opposite side of the chain fixed guide rail are provided with a timing groove array, the timing groove array comprises at least two timing grooves which are arranged in parallel along a timing adjusting direction, and the timing grooves are matched with the timing convex ribs.

2. The engine timing mechanism according to claim 1, wherein said engine cylinder head includes a cylinder head body and a cylinder head limiting portion extending from an edge of said cylinder head body, said cylinder head body being provided with a cylinder head connecting hole; the timing groove array is positioned between the cylinder cover connecting hole and the cylinder cover limiting part;

the chain fixed guide rail comprises a guide rail connecting part and a guide rail limiting part extending from the edge of the guide rail connecting part, a guide rail connecting hole is formed in the guide rail connecting part, and the timing convex rib is positioned between the guide rail connecting hole and the guide rail limiting part;

the engine timing mechanism further comprises a bolt and nut assembly for being assembled in the cylinder cover connecting hole and the guide rail connecting hole.

3. The engine timing mechanism according to claim 2, wherein an inner wall of said guide rail stopper portion is located inside an outer common tangent of said crankshaft sprocket and said camshaft sprocket; a first gap for accommodating the timing chain is formed between one tail end of the guide rail limiting part and the camshaft chain wheel, and a second gap for accommodating the timing chain is formed between the other tail end of the guide rail limiting part and the crankshaft chain wheel.

4. The engine timing mechanism according to claim 2, characterized in that an adjustment displacement space in which the timing adjustment direction matches is formed in the guide rail attachment hole.

5. The engine timing mechanism according to claim 4, wherein the guide rail attachment hole is a racetrack-shaped hole including a rectangular area and two tangential semicircular areas extending from a short side direction of the rectangular area, and the adjustment displacement space is the rectangular area.

6. The engine timing mechanism of claim 1 wherein said chain guide has an offset extension gap at an end of said chain guide adjacent said camshaft sprocket.

7. The engine timing mechanism of claim 1, wherein said timing rib is a triangular rib and said timing groove is a triangular groove.

8. The engine timing mechanism according to claim 1, characterized in that the number of the timing beads is at least one, and the number of the timing grooves is larger than the number of the timing beads.

9. The engine timing mechanism of claim 1, wherein said timing groove array has a width of 3mm to 5 mm.

10. An engine comprising a crankshaft and two camshafts, further comprising an engine timing mechanism as claimed in any one of claims 1 to 9, said crankshaft sprocket being fitted to said crankshaft; the camshaft sprocket is assembled on the camshaft.

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