Single-cylinder three-valve V-shaped two-cylinder engine valve mechanism

Abstract

The invention relates to a single-cylinder three-valve V-shaped two-cylinder engine valve mechanism. The air cylinder comprises cylinder bodies of two air cylinders which are arranged in a V shape, and cylinder covers of the cylinder bodies are provided with two air inlet valves and an exhaust valve. The cam shaft is provided with four cams along the axial direction; the crankshaft is connected with the cam shaft through a synchronous transmission mechanism; the four tappets are correspondingly arranged on one sides of the four cams respectively, and the four tappets are staggered in the axial direction of the crankshaft and are arranged at intervals; each tappet comprises a tappet driven part and a tappet pressure point part; the rocker arm mechanism comprises an air inlet rocker arm shaft, an exhaust rocker arm shaft, an air inlet rocker arm and an exhaust rocker arm, the air inlet rocker arm and the exhaust rocker arm are correspondingly and rotationally connected with the air inlet rocker arm shaft and the exhaust rocker arm shaft, and the air inlet rocker arm comprises an air inlet rocker arm driven part and two air inlet rocker arm valve pressure point parts; the exhaust rocker arm comprises an exhaust rocker arm driven part and an exhaust rocker arm valve pressure point part. The problem that a V-shaped two-cylinder engine is high in cost is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of engines, and in particular to a single-cylinder three-valve V-type two-cylinder engine valve mechanism. Background Art

[0002] V-type two-cylinder engines generally adopt a single-cylinder, two-valve structure (single cylinder is equipped with one intake valve and one exhaust valve) such as the Kohler CH1000 engine, the Breitling Vanguard engine, the Kawasaki FD851D engine, and the Loncin LC2V90FD. These engines are air-cooled or water-cooled engines, with a mid-camshaft mechanism for valve distribution. They have a simple structure and low cost. They are generally used as general-purpose engines in mobile generator sets, beach cars, lawn mowers, water pumps, etc. Their power performance, economy performance, and emission performance cannot meet the requirements of automotive-grade range extenders.

[0003] In addition, there are also some V-type two-cylinder engines that use a single-cylinder four-valve structure (a single cylinder is equipped with two intake valves and two exhaust valves) matched with an overhead dual camshaft structure, such as the KTM950 V2 engine and the CFMOTO V-type two-cylinder engine. Such engines are generally water-cooled and have a dual overhead camshaft structure. They have excellent performance but a complex structure and high cost, and are mostly used in the field of large-displacement motorcycles.

[0004] Therefore, how to take into account the strict requirements of the automotive grade on power performance, economy, emissions and other aspects in the design of the valve mechanism of the V-type two-cylinder engine, while effectively controlling the manufacturing costs so that it can be accepted by the small car market, has become an important direction and difficulty in current technological research and development. Summary of the Invention

[0005] To this end, the present invention provides a single-cylinder three-valve V-type two-cylinder engine valve mechanism, which can effectively reduce the cost of the V-type two-cylinder engine while meeting various automotive-grade performance requirements, and further improve its advantage in matching a small-power range extender.

[0006] To solve the above technical problems, the present invention provides a single-cylinder three-valve V-type two-cylinder engine valve mechanism, comprising: A cylinder block with two cylinders arranged in a V-shape, wherein a cylinder head is provided on the cylinder block corresponding to each cylinder, and each cylinder head is provided with two intake valves and one exhaust valve; A camshaft is arranged between the two cylinders, and the camshaft is provided with four cams along the axial direction; a crankshaft connected to the camshaft via a synchronous transmission mechanism; Four tappets are respectively arranged on one side of the four cams and driven by the corresponding cams, and the four tappets are staggered and spaced apart along the axial direction of the crankshaft; Four tappets, each of the tappets comprising a driven portion and a tappet pressure point portion, the driven portion of each tappet being movably connected to the corresponding tappet, and an axial projection of two adjacent tappets forming a V-shape; A rocker arm mechanism, comprising an intake rocker arm shaft and an exhaust rocker arm shaft mounted on each of the cylinder heads, and an intake rocker arm and an exhaust rocker arm rotatably connected to the intake rocker arm shaft and the exhaust rocker arm shaft, wherein the intake rocker arm comprises an intake rocker arm driven portion and two intake rocker arm valve pressure point portions, and the exhaust rocker arm comprises an exhaust rocker arm driven portion and an exhaust rocker arm valve pressure point portion; Wherein, the driven portion of the intake rocker arm and the driven portion of the exhaust rocker arm can abut against the corresponding tappet pressure point portion of the tappet; The two intake rocker arm valve pressure point portions of the intake rocker arm can respectively abut against the corresponding two intake valves; One of the exhaust rocker arm valve pressure point portions of the exhaust rocker arm can abut against the corresponding exhaust valve.

[0007] In one embodiment of the present invention, the cylinder block is provided with a left cylinder and a right cylinder, the cylinder head includes a left cylinder head provided on the left cylinder and a right cylinder head provided on the right cylinder, the left cylinder head is provided with a left cylinder head air inlet and a left cylinder head exhaust port, and the right cylinder head is provided with a right cylinder head air inlet and a right cylinder head exhaust port; Among them, the left cylinder head air inlet and the right cylinder head air inlet are respectively located on the corresponding inner sides of the left cylinder head and the right cylinder head obliquely forward, and the left cylinder head exhaust port and the right cylinder head exhaust port are respectively located on the corresponding outer sides of the left cylinder head and the right cylinder head obliquely backward, and the intake directions of the left cylinder head air inlet and the right cylinder head air inlet form an angle of 0~90° with the axial direction of the crankshaft.

[0008] In one embodiment of the present invention, the direction of a line connecting the valve pressure points of the two intake rocker arms is the same as the direction of a line connecting the center lines of the corresponding two intake valves.

[0009] In one embodiment of the present invention, the intake rocker arm driven portion and the exhaust rocker arm driven portion are respectively configured as ball sockets, and the tappet pressure point portion is configured as a spherical shape.

[0010] In one embodiment of the present invention, the synchronous transmission mechanism adopts timing belt transmission, gear transmission or chain transmission.

[0011] In one embodiment of the present invention, the tappet is a hydraulic tappet or a mechanical tappet.

[0012] In one embodiment of the present invention, the tappet pressure point is arranged at the front end or rear end edge of the cylinder head to avoid the combustion chamber and the water jacket in the cylinder head.

[0013] The above technical solution of the present invention has the following advantages over the prior art: The single-cylinder three-valve V-type two-cylinder engine valve mechanism described in the present invention reduces the number of camshafts in the conventional V-type two-cylinder engine dual overhead camshaft solution by designing a valve distribution mode of the mid-camshaft, thereby effectively reducing the cost of the V-type two-cylinder engine. In addition, the single-cylinder three-valve structure (two intake valves and one exhaust valve) is adopted without having a significant impact on the performance, which can further reduce the cost and further enhance its advantage in matching with a low-power range extender.

[0014] This invention utilizes a single camshaft positioned centrally between the two cylinders in the engine block. Four cams are arranged axially, complemented by staggered tappets and rods, resulting in a more compact valvetrain layout. The rocker arm mechanism utilizes independent intake and exhaust rocker shafts, each connected to its corresponding shaft. This not only improves assembly flexibility but also facilitates subsequent maintenance and overhaul, reducing both difficulty and cost.

[0015] The intake direction of this invention forms an angle with the crankshaft axis, optimizing airflow distribution and improving gas exchange and thermal management efficiency. Furthermore, the tappet pressure point is located at the edge of the cylinder head, effectively avoiding the combustion chamber and water jacket, ensuring cooling efficiency and combustion stability, making it ideal for the design requirements of small and compact engines. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to make the contents of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments of the present invention in conjunction with the accompanying drawings.

[0017] Figure 1 It is a schematic diagram of the overall structure of the valve train of a V-type two-cylinder engine with three valves in a single cylinder according to the present invention.

[0018] Figure 2 It is a schematic top view of the overall structure of the valve train of a single-cylinder three-valve V-type two-cylinder engine of the present invention.

[0019] Figure 3 yes Figure 1 Schematic diagram of direction B in .

[0020] Figure 4 It is a structural schematic diagram of one side of the rocker arm mechanism of the valve train of a single-cylinder three-valve V-type two-cylinder engine of the present invention.

[0021] Figure 5 It is a structural schematic diagram of the other side of the rocker arm mechanism of the valve train of a single-cylinder three-valve V-type two-cylinder engine of the present invention.

[0022] Description of the accompanying drawings: 1. Cylinder block; 1a. Left cylinder; 1b. Right cylinder; 11a. Left cylinder head; 11b. Right cylinder head; 12. Left cylinder head air intake; 13. Left cylinder head exhaust; 14. Right cylinder head air intake; 15. Right cylinder head exhaust; 2. Cylinder head; 21. Intake valve; 22. Exhaust valve; 3. Camshaft; 4. Crankshaft; 5. Synchronous transmission mechanism; 6. Pillar; 7. Tappet; 71. Tappet driven portion; 72. Tappet pressure point; 8. Rocker arm mechanism; 81a. Intake rocker arm; 81b. Exhaust rocker arm; 811a. Intake rocker arm driven portion; 812a. Intake rocker arm valve pressure point portion; 82a. Intake rocker arm shaft; 82b. Exhaust rocker arm shaft; 811b. Exhaust rocker arm driven portion; 812b. Exhaust rocker arm valve pressure point portion. DETAILED DESCRIPTION

[0023] The present invention will be further described below with reference to the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it. However, the embodiments are not intended to limit the present invention.

[0024] In the present invention, if directions (up, down, left, right, front and back) are described, it is only for the convenience of describing the technical solution of the present invention, and does not indicate or imply that the technical features referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, it cannot be understood as a limitation of the present invention.

[0025] In the present invention, "several" means one or more, "multiple" means more than two, "greater than," "less than," "exceeds," etc. are understood to exclude the number itself; "above," "below," "within," etc. are understood to include the number itself. In the description of the present invention, the use of "first" or "second" is solely for the purpose of distinguishing technical features and is not to be construed as indicating or implying relative importance, implicitly specifying the number of the indicated technical features, or implicitly specifying the order of the indicated technical features.

[0026] In the present invention, unless otherwise expressly defined, terms such as "disposed," "installed," and "connected" should be interpreted broadly. For example, they may refer to direct connection or indirect connection through an intermediate medium; fixed connection or detachable connection or integral molding; mechanical connection or electrical connection or mutual communication; and internal connection between two components or interaction between two components. Those skilled in the art can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0027] Reference Figure 1 、 Figure 4 、 Figure 5 As shown, the present invention is a single-cylinder three-valve V-type two-cylinder engine valve mechanism, comprising: A cylinder block 1 with two cylinders arranged in a V shape, wherein a cylinder head 2 is provided on the cylinder block 1 corresponding to each cylinder, and each cylinder head 2 is provided with two intake valves 21 and one exhaust valve 22; A camshaft 3 is arranged between the two cylinders, and the camshaft 3 is provided with four cams along the axial direction; The crankshaft 4 is connected to the camshaft 3 through a synchronous transmission mechanism 5; Four tappets 6 are respectively disposed on one side of the four cams and driven by the corresponding cams. The four tappets 6 are axially staggered and spaced apart along the crankshaft 4. Four tappets 7 , each of which includes a driven portion 71 and a pressure point portion 72 , wherein the driven portion 71 of each tappet 7 is movably connected to the corresponding tappet 6 , and an axial projection of two adjacent tappets 7 forms a V shape; The rocker arm mechanism 8 includes an intake rocker arm shaft 82a and an exhaust rocker arm shaft 82b mounted on each of the cylinder heads 2, and an intake rocker arm 81a and an exhaust rocker arm 81b rotatably connected to the intake rocker arm shaft 82a and the exhaust rocker arm shaft 82b, respectively. The intake rocker arm 81a includes an intake rocker arm driven portion 811a and two intake rocker arm valve pressure point portions 812a, and the exhaust rocker arm 81b includes an exhaust rocker arm driven portion 811b and an exhaust rocker arm valve pressure point portion 812b. The intake rocker arm driven portion 811a and the exhaust rocker arm driven portion 811b are capable of abutting against the corresponding tappet pressure point portion 72 of the tappet 7; The two intake rocker arm valve pressure point portions 812a of the intake rocker arm 81a can respectively abut against the corresponding two intake valves 21; One of the exhaust rocker arm valve pressure point portions 812 b of the exhaust rocker arm 81 b can abut against the corresponding exhaust valve 22 .

[0028] In one embodiment, referring to Figure 2 As shown, the cylinder block 1 is provided with a left cylinder 1a and a right cylinder 1b, and the cylinder head 2 includes a left cylinder head 11a provided on the left cylinder 1a and a right cylinder head 11b provided on the right cylinder 1b. The left cylinder head 11a is provided with a left cylinder head air intake port 12 and a left cylinder head exhaust port 13, and the right cylinder head 11b is provided with a right cylinder head air intake port 14 and a right cylinder head exhaust port 15; The left cylinder head air inlet 12 and the right cylinder head air inlet 14 are respectively located on the inner side of the corresponding left cylinder head 11a and the right cylinder head 11b, obliquely forward, and the left cylinder head exhaust port 13 and the right cylinder head exhaust port 15 are respectively located on the outer side of the corresponding left cylinder head 11a and the right cylinder head 11b, obliquely backward. The air intake direction of the left cylinder head air inlet 12 and the right cylinder head air inlet 14 is ( Figure 2 The X direction) forms an angle of 0 to 90 degrees with the axial direction of the crankshaft 4.

[0029] In one embodiment, referring to Figure 4 、 Figure 5 As shown, the intake rocker arm 81a is rotatably connected to the intake rocker shaft 82a, and the exhaust rocker arm 81b is rotatably connected to the exhaust rocker shaft 82b. The intake rocker arm 8a actuates two intake valves 21, while the exhaust rocker arm 81b directly actuates a single exhaust valve 22. The direction of the line connecting the valve pressure points 812a of the two intake rocker arms is the same as the direction of the line connecting the centerlines of the corresponding two intake valves 21.

[0030] In one embodiment, the intake rocker arm driven portion 811a and the exhaust rocker arm driven portion 811b are respectively constructed as ball sockets, and the push rod pressure point portion 72 is constructed as a spherical shape, which helps to reduce friction, improve force uniformity and mechanical efficiency, while extending the service life of components and improving the reliability and wear resistance of the mechanism.

[0031] In one embodiment, the synchronous transmission mechanism 5 adopts a timing belt drive, a gear drive or a chain drive. Preferably, a gear drive is adopted, as the gear drive has low cost, simple structure and simplified maintenance process.

[0032] In one embodiment, considering the requirement of non-sensing of the range extender, preferably, the tappet 6 adopts a hydraulic tappet that is beneficial to reducing vibration noise. If further cost reduction is considered, a mechanical tappet may also be used instead.

[0033] In one embodiment, the tappet pressure point 72 is disposed at the front end or rear end edge of the cylinder head 2 to avoid the combustion chamber and the water jacket in the cylinder head 2 .

[0034] Taking gear transmission as an example, when working, the camshaft 3 is driven by the crankshaft 4 through gears, the cam pushes the corresponding tappet 6 and then drives the tappet 7 to push the intake rocker arm 81a, and then pushes the two intake valves 22, the tappet 7 pushes the exhaust rocker arm 81b and then drives an exhaust valve 22, completing the valve timing action.

[0035] By using the middle camshaft 3, the number of camshafts 3 required by the traditional V-type two-cylinder engine is significantly reduced, the valve drive path is simplified, and the number of parts and system complexity are reduced. Under the premise of not significantly affecting the engine power performance, the single-cylinder three-valve (two intake valves 21 and one exhaust valve 22) configuration is adopted, which further optimizes the valve system structure. Compared with the double-overhead camshaft 3 four-valve scheme, the material, machining, assembly and maintenance costs are effectively reduced, making the valve train more suitable for the cost-sensitive passenger car range extender and small power engine market.

[0036] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present application and are not limiting. Although the present application has been described in detail with reference to the examples, it should be understood by those skilled in the art that the technical solutions of the present application can be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present application, which should be covered by the scope of the claims of the present application.

Claims

1. A single-cylinder three-valve V-type two-cylinder engine valve train, characterized in that: include: A cylinder body (1) having two cylinders arranged in a V-shape, wherein a cylinder head (2) is provided on the cylinder body (1) corresponding to each cylinder, and each cylinder head (2) is provided with two intake valves (21) and one exhaust valve (22); A camshaft (3) is arranged between the two cylinders, and the camshaft (3) is provided with four cams along the axial direction; A crankshaft (4) connected to the camshaft (3) via a synchronous transmission mechanism (5); Four tappets (6) are respectively arranged on one side of the four cams and driven by the corresponding cams. The four tappets (6) are axially staggered and spaced apart along the crankshaft (4); Four tappets (7), each of the tappets (7) comprising a tappet driven portion (71) and a tappet pressure point portion (72), the tappet driven portion (71) of each tappet (7) being movably connected to the corresponding tappet (6), and the axial projections of two adjacent tappets (7) forming a V shape; A rocker arm mechanism (8), comprising an intake rocker arm shaft (82a) and an exhaust rocker arm shaft (82b) mounted on each of the cylinder heads (2), and an intake rocker arm (81a) and an exhaust rocker arm (81b) rotatably connected to the intake rocker arm shaft (82a) and the exhaust rocker arm shaft (82b), wherein the intake rocker arm (81a) comprises an intake rocker arm driven portion (811a) and two intake rocker arm valve pressure point portions (812a), and the exhaust rocker arm (81b) comprises an exhaust rocker arm driven portion (811b) and an exhaust rocker arm valve pressure point portion (812b); The intake rocker arm driven portion (811a) and the exhaust rocker arm driven portion (811b) are capable of abutting against the corresponding tappet pressure point portion (72) of the tappet (7); The two intake rocker arm valve pressure point portions (812a) of the intake rocker arm (81a) can respectively abut against the corresponding two intake valves (21); One of the exhaust rocker arm valve pressure point portions (812b) of the exhaust rocker arm (81b) is capable of abutting against the corresponding exhaust valve (22).

2. A single-cylinder three-valve V-type two-cylinder engine valve train according to claim 1, characterized in that: The cylinder body (1) is provided with a left cylinder (1a) and a right cylinder (1b); the cylinder head (2) comprises a left cylinder head (11a) provided on the left cylinder (1a) and a right cylinder head (11b) provided on the right cylinder (1b); the left cylinder head (11a) is provided with a left cylinder head air intake port (12) and a left cylinder head exhaust port (13); the right cylinder head (11b) is provided with a right cylinder head air intake port (14) and a right cylinder head exhaust port (15); The left cylinder head air inlet (12) and the right cylinder head air inlet (14) are respectively located on the inner side of the corresponding left cylinder head (11a) and the right cylinder head (11b) obliquely forward, and the left cylinder head exhaust port (13) and the right cylinder head exhaust port (15) are respectively located on the outer side of the corresponding left cylinder head (11a) and the right cylinder head (11b) obliquely backward, and the respective intake directions of the left cylinder head air inlet (12) and the right cylinder head air inlet (14) form an angle of 0 to 90 degrees with the axial direction of the crankshaft (4).

3. A single-cylinder three-valve V-type two-cylinder engine valve train according to claim 1, characterized in that: The direction of the line connecting the two intake rocker arm valve pressure point portions (812a) is the same as the direction of the line connecting the center lines of the corresponding two intake valves (21).

4. A single-cylinder three-valve V-type two-cylinder engine valve train according to claim 1, characterized in that: The intake rocker arm driven portion (811a) and the exhaust rocker arm driven portion (811b) are respectively constructed as ball sockets, and the tappet pressure point portion (72) is constructed as a sphere.

5. The single-cylinder three-valve V-type two-cylinder engine valve train according to claim 1, characterized in that: The synchronous transmission mechanism (5) adopts timing belt transmission, gear transmission or chain transmission.

6. The single-cylinder three-valve V-type two-cylinder engine valve train according to claim 1, characterized in that: The tappet (6) is a hydraulic tappet or a mechanical tappet.

7. The single-cylinder three-valve V-type two-cylinder engine valve train according to claim 1, characterized in that: The tappet pressure point portion (72) is arranged at the front end or rear end edge of the cylinder head (2) to avoid the combustion chamber and the water jacket in the cylinder head (2).

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