WO2008052402A1 - Four stroke overhead cam engine - Google Patents

Abstract

A four stroke overhead cam engine is provided, wherein an engine body (1) is formed integrally by a cylinder cover (44), a cylinder block (9), an upper crankcase half (46) and a chain chamber (45), a combustion chamber (11) is disposed at the upper portion of the cylinder block (9), an intake valve (24) and an exhaust valve (25) are arranged at the two sides of the cylinder axis (B1-B1) respectively, a cam shaft (31) is arranged centrally between the intake valve (24) and the exhaust valve (25), which parallels to a crankshaft (16) and intersects with cylinder axis (B1-B1) perpendicularly, a rocking arm shaft (35) is arranged centrally between an intake rocking arm (36) and an exhaust rocking arm (37) and parallels to the crankshaft (16). The size of the engine head is reduced by decreasing the seal surface of the engine body and the amount of the valve driving machine parts, which has advantage of the cooling of the engine head, thereby the engine reliability is improved.

Description

 Four-stroke overhead cam engine

 The invention relates to a four-stroke overhead cam engine, belonging to the technical field of power plants. Background technique

 At present, a general four-stroke overhead cam engine has a cylinder head and a body separately cast into a separate structure, and the cylinder head is bolted to the body, and then the camshaft is mounted on the cylinder head, and the assembly is overlapped. The number of parts is large, and the number of sealing faces is increased to increase the number of processing hours. It is necessary to add gasket-like parts to the sealing surface to increase the dependence of the sealing, thereby increasing the wall thickness of the cylinder. In addition, a single overhead camshaft is commonly used to increase the height of the engine, and a double overhead camshaft is added to increase the width of the cylinder head. This kind of structure is disadvantageous for the weight reduction of the engine and the heat dissipation of the cylinder head. A new overhead cam engine is also proposed in the U.S. Patent No. 5,706,769, the intake and exhaust valves and the intake and exhaust cam followers are provided in a single valve operating cam in the cylinder head. The opposite sides. The intake and exhaust valves are parallel to each other and perpendicular to the crankshaft. The intake and exhaust cam followers form a two-part structure. One arm of the intake and exhaust cam followers extends inwardly toward each other, respectively contacting the intake and exhaust valves, and the other arm also extends inwardly toward each other, contacting the valve operating cam below the center of rotation of the valve operating cam a cam surface, which is arranged on the two sides of the cam shaft, adopts a cam shaft and two rocker shafts, thereby increasing the number of parts, and the reciprocating range of the two rocker shafts is increased, directly affecting The heat dissipation of the cylinder head particularly affects the heat dissipation at the contact between the exhaust valve seat and the combustion chamber.

 Summary of the invention

 The object of the present invention is to overcome the above-mentioned deficiencies, thereby providing a whole body and a cylinder head, reducing the sealing surface, achieving weight reduction of the engine, and improving heat dissipation of the cylinder head; and arranging the camshaft and the rocker arm in two The middle position of the valve does not increase the width of the cylinder head, and also reduces the height of the engine. By reducing the number of parts of the entire valve drive mechanism, the size of the engine head is reduced, which is beneficial to the cooling outside the engine combustion chamber, and can be improved. The reliability of the whole machine.

 The main solution of the invention is achieved in this way:

In the invention, the body, the crankcase cover and the cylinder head cover are die-casted from aluminum alloy or magnesium alloy; Connected to the crankcase cover, the joint surface of the body and the crankcase cover passes through the crankshaft axis Al-Al and the cylinder axis B1-B1, and the crankshaft is mounted on the body machine through the bearing support; the piston is installed in the cylinder cylinder, and the combustion chamber is composed of a piston, a body, The cylinder barrel is formed, and the piston is connected to the crankshaft through the connecting rod set, and the feature is:

 The body is integrally formed by the cylinder head, the cylinder barrel, the upper crankcase half box and the chain chamber, and the cylinder head cover is fixed on the cylinder head; the upper part of the body is provided with an intake passage and an exhaust passage, and the intake passage and the exhaust passage are respectively located in the cylinder. Both sides of the axis B1-B1; a hole is provided in the inlet passage at an inclination from the cylinder axis B1-B1, the intake valve guide is installed in the hole, the hole is coaxial with the intake valve seat, and the inlet valve is bored Intake port; a hole is provided in the intake passage at an inclination from the cylinder axis B1-B1, the intake valve guide is installed in the hole, the hole is coaxial with the intake valve seat, and an exhaust valve is worn in the intake valve guide;

 In the upper part of the body, a camshaft is arranged through the shaft, the camshaft is arranged at an intermediate position between the intake valve and the exhaust valve, the camshaft is parallel to the crankshaft, and intersects with the cylinder axis B1-B1, perpendicular; the crankshaft is equipped with a timing gear; a chain or belt is accommodated in the chamber, and a timing chain or belt connects the camshaft with the toothed shape to the timing gear;

 There is a valve rocker seat on the upper part of the body, the rocker arm shaft is installed in the valve rocker arm seat, and the rocker arm shaft is arranged in the middle position between the intake valve rocker arm and the exhaust valve rocker arm, the rocker arm shaft is parallel with the crankshaft, and is worn The vertical and vertical cylinder axis B1-B1 is located at the upper part of the camshaft; the inlet and exhaust valve rocker arms are crossed on the rocker arm shaft, the upper end and the lower end of the intake valve rocker arm, and the upper and lower ends of the exhaust valve rocker arm respectively Located on both sides of the crankshaft axis A1 - A1, the intake valve rocker arm and the exhaust valve rocker arm can swing around the rocker arm axis;

 An integral cam is formed on the camshaft or an integral intake cam and an exhaust cam are formed; the intake rocker arm is divided into two sections, an upper end and a lower end, the upper end is connected to the intake-door root, and the lower end is formed into an arc. Contact with a cam or an exhaust cam;

 The exhaust valve rocker arm is divided into two sections, the upper end and the lower end, the upper end is connected with the root of the exhaust valve, and the lower end is formed into a circular arc shape to be in contact with the camshaft;

 The present invention has the following advantages over the prior art:

The invention has the advantages of simple structure, compactness and reasonableness; the whole body and the cylinder head are integrated, the sealing surface is reduced, the weight of the engine is realized, and the heat dissipation of the cylinder head is improved; and the cam shaft and the rocker arm are arranged in the middle position of the two valves. , reducing the width of the cylinder head and reducing the height of the engine; reducing the size of the engine head by reducing the number of parts of the entire valve drive mechanism 01081 Cooling outside the engine's combustion chamber improves the reliability of the machine; the structure can be widely used in gasoline engines, diesel engines, single-cylinder, multi-cylinder, air-cooled, water-cooled and other four-stroke engines.

 DRAWINGS

 BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a longitudinal sectional view showing the structure of the present invention (Embodiment 1).

 Figure 2 is a cross-sectional view of the structure A-A of the present invention.

 Figure 3 is a plan view of the structure 2 of the present invention.

 Figure 4 is a cross-sectional view taken along line B-B of Figure 3 of the present invention.

 Figure 5 is an exploded view of the structural valve operating mechanism of the present invention.

 Figure 6 is a longitudinal sectional view showing the structure of the present invention (Embodiment 2).

 Figure 7 is a plan view of the structure of Figure 6 of the present invention.

 Figure 8 is a cross-sectional view taken along line C-C of Figure 6 of the present invention.

 detailed description

 The invention will be further described below in conjunction with the embodiments of the drawings:

 The invention mainly consists of a body 1, a crankcase cover 2, a cylinder head cover 3, a joint surface 4, a bolt 5, a crankshaft 6, a bearing 7, 8, a cylinder barrel 9, a piston 10, a combustion chamber 11, a connecting rod set 12, and a piston pin. 13. Intake passage 14, exhaust passage 15, intake valve seat 16, exhaust valve seat 17, intake pipe 18, exhaust pipe 19, intake valve guide 20, exhaust valve guide 21, bore 22, bore 23 Intake valve 24, exhaust valve 25, intake valve spring 26, exhaust valve spring 27, valve spring seat 28, valve spring seat 29, shaft 30, camshaft 31, timing gear 32, timing chain or belt 33. Valve rocker arm seat 34, rocker arm shaft 35, intake valve. Rocker arm 36 (upper end 38, lower end 39), exhaust valve rocker arm 37 (upper end 40, lower end 41), valve adjustment. Screw 42a, valve adjustment The nut 43a, the valve adjusting screw 42b, the valve adjusting nut 43b, the engine head 44, the chain chamber 45, the upper crankcase 46, the cam 47, the spark plug 48, the intake cam 49, and the exhaust cam 50 are formed.

 Embodiment 1: (Intake and exhaust valves share one cam)

The invention relates to a single-cylinder air-cooled overhead cam type gasoline engine. The main engine body 1, the crankcase cover 2 and the cylinder head cover 3 are molded by an aluminum alloy or a magnesium alloy. The body 1 and the crankcase cover 2 are diagonally divided at the joint surface 4, and are connected by a plurality of sets of bolts 5. The joint face 4 of the body 1 with the crankcase cover 2 passes through the crankshaft axis A1-A1 and the cylinder axis B1-B1. The rotation of the crankshaft 6 is through a bearing 7 and a bearing 8 which are worn at both ends, and the bearing 7 is supported on the body machine 1, and the bearing 8 is supported on the crankcase cover 2. The engine block 1 is integrally formed by a cylinder head 44, an upper crankcase half box 46, a cylinder barrel 9, and a chain chamber 45. The cylinder head cover 3 is fixed to the cylinder head 44, and a piston 10 is mounted in the cylinder barrel 9, and the combustion chamber 11 is installed. It is formed by the piston 10, the body 1, and the cylinder barrel 9. The piston 10 is coupled to the crankshaft 6 via a linkage 12, and the linkage of the linkage 12 to the crankshaft 6 is relatively free to rotate. The connection of the piston 10 and the link set 12 is through a piston pin 13 and is relatively free to oscillate.

 The engine body 1 also has a preformed intake port 14 and an exhaust passage 15, and an intake passage 1 and an exhaust passage 15 are respectively located on both sides of the cylinder axis Bl-B1. One end of the intake passage 14 leads to the combustion chamber 11, and an intake valve seat 16 is press-fitted at the junction, and the other end forms a plane outside the body 1, which is connected to the intake pipe 18. One end of the exhaust passage 15 also leads to the combustion chamber 11, and a discharge valve seat 17 is press-fitted at the junction, and the other end forms a plane on the other side of the body 1 symmetric about the cylinder axis B1-B1, where the exhaust pipe is 19 connected. An intake hole 22 is bored in the intake passage 14 and the cylinder axis B1-B1 for press fitting an intake valve guide 20 coaxial with the intake valve seat 16, and an intake valve is bored in the intake valve guide 20. 24, the intake valve 24 is provided with a valve spring seat 28, between the valve spring seat 28 and the body 1, an intake valve spring 26 is coaxially mounted with the intake valve 24, so that when the intake valve spring 26 is compressed, the intake air The door 24 is moved downward, away from the intake door seat 16, and the intake air is unobstructed; when the intake valve spring 26 is reset, the intake valve 24 is moved up, and the intake valve seat 16 is attached, and the intake air is blocked. A hole 23 is bored in the exhaust passage 15 and the cylinder axis B1-B1 for press-fitting an exhaust valve guide 21 coaxial with the exhaust valve seat 17, and an exhaust valve is formed in the exhaust valve guide 21. 25, a valve spring seat 29 is mounted on the exhaust valve 25, and an exhaust valve spring 27 is disposed coaxially with the exhaust valve 25 between the valve spring seat 29 and the body 1, so that the exhaust valve spring 27 is compressed when exhausted The door 25 is moved downward, and is separated from the exhaust valve seat 17, and the exhaust air is unobstructed. When the exhaust valve spring 27 is reset, the exhaust valve 25 is moved up, and the exhaust valve seat 17 is attached to the exhaust valve seat 17, and the exhaust gas is blocked.

Also mounted on the upper portion of the body 1 is a cam shaft 31 which is disposed at an intermediate position between the two valves by a shaft 30. The cam shaft 31 is parallel to the crankshaft 6 and intersects the cylinder axis B1-B1, perpendicular. The cam shaft 31 is provided with an integrally formed cam 47 which is free to rotate on the shaft 30. The rotation of the camshaft 31 is mainly driven by the crankshaft 6. The crankshaft 6 has a timing gear 32. The timing gear 32 is interposed on the crankshaft 6 and rotates together with the crankshaft. A chain or belt 33 is accommodated in the chain chamber 45, and a timing chain or belt 33 is placed thereon. The toothed cam shaft 31 is coupled with the timing gear 32; and the rotation of the crankshaft 6 and the camshaft 31 is ensured by the number of teeth The ratio is 2:1. The cam 47 on the camshaft 31 is offset from the misalignment of the intake and exhaust valves 24, 25. The upper portion of the body 1 is provided with a protruding valve rocker seat 34. The rocker arm shaft 35 is mounted in the valve rocker arm seat 34, and the rocker arm shaft 35 is arranged. In the intermediate position between the intake valve rocker arm 36 and the exhaust valve rocker arm 37, the rocker arm shaft 35 is parallel to the crankshaft 6 and passes through and perpendicular to the cylinder axis B1-B1 at the upper portion of the camshaft 31; due to the inclination of the valve, The rocker arm is conveniently disposed at an intermediate position between the two valves; one end of the rocker arm shaft 35 is formed to protrude against the cylinder head cover 3 to prevent slippage. The intake valve rocker arm 36 is divided into two sections, an upper end 38, a lower end 39, and an upper end 38 is provided with a valve adjusting screw 42a. The valve adjusting nut 43a is connected to the root of the intake valve 24, and the lower end 39 is in a circular arc shape and is in contact with the cam 47; The valve rocker arm 37 is divided into two sections, an upper end 40, a lower end 41, and an upper end 40 is provided with a valve adjusting screw 42b. The valve adjusting nut 43b is connected to the root of the exhaust valve 25, and the lower end 41 is in a circular arc shape and is in contact with the cam shaft 31; The exhaust valve rocker arms 36, 37 share a rocker arm shaft 35, and a cam 47, and the intake and exhaust valve rocker arms 36, 37 cross over the rocker arm shaft 35 to be coupled to the body 1, so that the intake valve The upper end 38 and the lower end 39 of the rocker arm 36, the upper end 40 and the lower end 41 of the exhaust valve rocker arm 37 are respectively located on both sides of the crankshaft axis A1-A1, and the intake valve rocker arm 36 and the exhaust valve rocker arm 37 can be rocked around. The arm shaft 35 is swung.

 Its working process:

 When the crankshaft 6 rotates, the crankshaft 6 drives the camshaft 31 to rotate by 1/2 of the number of revolutions by the timing chain 33, thereby pushing the lower end 39 of the intake valve rocker arm 36 and the exhaust valve rocker arm 37 which are in contact therewith by the cam 47. The lower end 41. The upper end 38 of the intake valve rocker arm 36 and the upper end 40 of the exhaust valve rocker arm 37 are swung to overcome the resistance of the intake valve spring 26 and the exhaust valve spring 27, and the intake valve 24 and the exhaust valve 25 are opened.

 On the other hand, the lower end 39 of the intake valve rocker arm 36 and the lower end 41 of the exhaust valve rocker arm 37 abut against the cam 47, and when the cam 47 continues to rotate, there is no pressure on the intake valve rocker arm 36 and the exhaust valve rocker arm 37. The intake valve 24 and the exhaust valve 25 are opened by the elastic force of the intake valve spring 26 and the exhaust valve spring 27, and the reset of the intake valve rocker arm 36 and the exhaust valve rocker arm 37 is completed.

 Embodiment 2: (A cam is used for each of the intake and exhaust valves)

 The engine block 1 is integrally formed by a cylinder head 44, a cylinder barrel 9 accommodating the piston, a chain chamber 45, and an upper crankcase half box 46. The top of the cylinder barrel 9 on the body forms a combustion chamber 11, where the spark plug 48 is used for timing. Ignite into the combustion chamber.

The upper part of the body 1 also has a preformed intake port 14 exhaust passage 15, intake passage 14 and exhaust Lanes 15 are located on either side of the cylinder axis Bl-B1. One end of the intake passage 14 leads to the combustion chamber 11, and an intake port seat 16 is press-fitted at the junction, and the other end forms a plane on the outside of the body 1. One end of the exhaust passage 15 also leads to the combustion chamber 11, and a discharge valve seat 17 is press-fitted at the junction, and the other end forms a plane on the other side of the body 1 which is symmetrical about the cylinder axis B1-B1. An intake hole 22 is bored in the intake passage 14 and the cylinder axis B1-B1 for press fitting an intake valve guide 20 coaxial with the intake valve seat 16, and an intake valve is bored in the intake valve guide 20. 24, a valve spring seat 28 is mounted on the intake valve 24, and an intake valve spring 26 is coaxially mounted with the intake valve 24 between the valve spring seat 28 and the body 1, so that when the intake valve spring 26 is compressed, The valve 24 is moved downward, and is separated from the intake valve seat 16, and the intake air is unobstructed; when the intake valve spring 26 is reset, the intake valve 24 is moved up, and the intake valve seat 16 is attached, and the intake air is blocked. A hole 23 is bored in the exhaust passage 15 and the cylinder axis B1-B1 for press-fitting an exhaust valve guide 21 coaxial with the exhaust valve seat 17, and an exhaust valve is formed in the exhaust valve guide 21. 25, the exhaust valve 25 is provided with a valve spring seat 29, and between the valve spring seat 29 and the body 1, an exhaust valve spring 27 is coaxially mounted with the exhaust valve 25, so that the exhaust valve spring 27 is compressed and exhausted. The door 25 is moved downward, and is separated from the exhaust valve seat 17, and the exhaust air is unobstructed. When the exhaust valve spring 27 is reset, the exhaust valve 25 is moved up, and the exhaust valve seat 17 is attached to the exhaust valve seat 17, and the exhaust gas is blocked.

 A cam shaft 31 is also mounted on the upper portion of the body 1 via a shaft 30. The cam shaft 31 is disposed at an intermediate position between the two valves. The cam shaft 31 is parallel to the crankshaft 6, and intersects the cylinder axis Bl-B1, perpendicular. The cam shaft 31 is provided with an intake cam 49 and an exhaust cam 50 which are integrally formed to drive the intake valve 24 and the exhaust valve 25, respectively.

There is also a protruding valve rocker seat 34 at the upper portion of the body 1 for assembling a rocker shaft 35 which is parallel to the crankshaft 6 and which passes through and is perpendicular to the cylinder axis B1-B1, located at the upper portion of the camshaft 30. Due to the tilting of the valve, the rocker arm is conveniently placed in the middle of the two valves. The intake valve rocker arm 36 is divided into two sections, an upper end 38 and a lower end 39. The upper end 38 is provided with a valve adjusting screw 42a. The valve adjusting nut 43a is connected to the root of the intake valve 24, and the lower end 39 is in a circular arc shape and is in contact with the intake cam 49. The exhaust valve rocker arm 37 is divided into two sections, an upper end 40 and a lower end 41. The upper end 40 is provided with a valve adjusting screw 42b. The valve adjusting nut 43b is connected to the root of the exhaust valve 25, and the lower end 41 has a circular arc shape and an exhaust cam 50. Contact; intake and exhaust valve rocker arms 36, 37 share a rocker arm shaft 35, and intake and exhaust valve rocker arms 36, 37 are threaded on the rocker arm shaft 35 to be coupled to the body 1, such that the intake valve rocker arm 36 Upper end 38. The lower end 39, the upper end 40 and the lower end 41 of the exhaust valve rocker arm 37 are respectively located on both sides of the crankshaft axis A1-A1, and the intake valve rocker arm 36 and the exhaust valve rocker arm 37 can swing around the rocker arm shaft 35.

 In this way, when the engine is working, the same camshaft rotates, and the intake and exhaust cams respectively open the intake and exhaust valves, and when the rotation continues, the intake and exhaust valves are closed correspondingly to ensure the four strokes of the engine. Reliable work.

Claims

Rights request 1. A four-stroke overhead cam engine, which is connected to a crankcase cover (2) by a body (1), and a crankshaft (6) is mounted on a body (1) by bearing support; a piston is mounted in the cylinder barrel (9) (10), the combustion chamber (11) is formed by a piston (10), a body (1), a cylinder barrel (9), and the piston (10) is connected to the crankshaft (6) through a connecting rod group (12), which is characterized by:  a. The body (1) is integrally connected by a cylinder head (44), a cylinder barrel (9), an upper crankcase half box (46), and a chain chamber (45), and the cylinder head cover (3) is fixed to the cylinder head (44). ;  b. The upper part of the body (1) is provided with an intake passage (14) and an exhaust passage (15), and the intake passage (14) and the exhaust passage (15) are respectively located on both sides of the cylinder axis (Bl-B1); A hole (22) is provided in the inlet passage (14) at an inclination from the cylinder axis (Bl-B1), and the intake valve guide (20) is installed in the hole (22), the hole (22) Coaxial with the intake valve seat (16), with an intake valve (24) in the intake valve guide (20); at the intake port (15) and the cylinder axis (Bl-B1) A hole (23) is provided, the intake valve guide (21) is mounted in the hole (23), the hole (22) is coaxial with the intake valve seat (17), and the intake valve guide (21) is exhausted Door (25);  c. The camshaft (31) is mounted on the upper part of the body (1) through the shaft (30). The camshaft (31) is arranged between the intake valve (24) and the exhaust valve (25). The camshaft (31) is parallel to Crankshaft (6), intersecting with cylinder axis (B1-B1), vertical; crankshaft (6) with timing gear (32); housing a chain or belt (33) in chain chamber (45), timing a chain or belt (33) connects the camshaft (31) to the timing gear (32);  d. There is a valve rocker seat (34) on the upper part of the body (1), the rocker arm shaft (35) is installed in the valve rocker seat (34), and the rocker arm shaft (35) is arranged on the intake valve rocker arm (36) ) In the middle of the exhaust valve rocker arm (37), the rocker arm shaft (35) is parallel to the crankshaft (6) and passes through the vertical cylinder axis (Bl-Bl), located at the upper part of the camshaft (31); The door rocker arm (36) and the exhaust valve rocker arm (37) are crossed on the rocker arm shaft (35), and the upper end (38), the lower end (39) of the intake valve rocker arm (36), and the exhaust valve rocker arm The upper end (40) and the lower end (41) of (37) are located on both sides of the crankshaft axis (Al-A1), and the intake valve rocker arm (36), the exhaust valve rocker arm (37) can swing around the rocker shaft (35); 2. A four-stroke overhead cam engine according to claim 1, wherein said camshaft (31) is provided with an integral cam (47) or an integral intake cam (49) and row. Air cam (50).  A four-stroke overhead cam engine according to claim 1 or 2, wherein the upper end (38) of the intake valve rocker arm (36) is connected to the root of the intake valve (24), and the lower end ( 39) Made into a circular arc and in contact with the cam (47).  4. A four-stroke overhead cam engine according to claim 3, wherein the upper end (40) of the exhaust valve rocker arm (37) is connected to the root of the exhaust valve (25), and the lower end (41) Made into a circular arc shape in contact with the camshaft (31);  A four-stroke overhead cam engine according to claim 4, wherein said cam shaft (31) is engraved with a tooth shape.  The four-stroke overhead cam engine according to claim 5, characterized in that the body (1), the crankcase cover (2) and the cylinder head cover (3) are respectively die-cast from aluminum alloy or magnesium alloy material. forming.