WO2016175104A1

WO2016175104A1 - Engine for saddled vehicles and saddled vehicle

Info

Publication number: WO2016175104A1
Application number: PCT/JP2016/062539
Authority: WO
Inventors: 哲治伊瀬知
Original assignee: ヤマハ発動機株式会社
Priority date: 2015-04-28
Filing date: 2016-04-20
Publication date: 2016-11-03
Also published as: JP2016205334A; EP3144493A1; EP3144493B1; EP3144493A4; ES2722532T3

Abstract

A cylinder head mounting section has a bolt hole formed in a cam holder, the bolt hole allowing a bolt for affixing a cylinder head to a cylinder to extend therethrough, the bolt hole also allowing lubricating oil to flow therethrough. A protrusion is formed integrally with the cam holder, protrudes from the cylinder head mounting section toward an intake valve or an exhaust valve, and conducts lubricating oil flowing from the upper end of the bolt hole. A guide section is formed as a separate body from the protrusion and extends toward the intake valve or the exhaust valve. The guide section includes a lubricating oil receiving section for receiving, below the protrusion, lubricating oil flowing along the protrusion. At a position located at a distance from the cylinder head mounting section, an extension section extends downward from the lower end of the protrusion toward the lubricating oil receiving section.

Description

Engine for saddle riding type vehicle and saddle riding type vehicle

The present invention relates to an engine for a saddle riding type vehicle and a saddle riding type vehicle.

A straddle-type vehicle engine having a cylinder and a cylinder head attached to the cylinder is known. A combustion chamber is formed by the cylinder and the cylinder head. The engine has an intake port and an intake valve. The intake port is connected to the combustion chamber. The intake valve opens and closes the flow of intake air flowing from the intake port to the combustion chamber. The engine has an exhaust port and an exhaust valve. The exhaust port is connected to the combustion chamber. The exhaust valve opens and closes the flow of exhaust flowing from the combustion chamber to the exhaust port.

A valve operating mechanism that drives an intake valve and / or an exhaust valve by a camshaft is known. The intake valve is pushed toward the combustion chamber via a rocker arm or the like as the camshaft rotates. When the intake valve is pushed, air-fuel mixture or air is taken into the combustion chamber from the intake port. The exhaust valve is pushed toward the combustion chamber via a rocker arm or the like as the camshaft rotates. When the exhaust valve is pushed toward the combustion chamber, the combustion gas is discharged from the combustion chamber to the exhaust port.

As described above, the exhaust valve and / or the exhaust valve is moved by another member. Since the exhaust valve and / or the contact portion between the exhaust valve and other members are worn, it is necessary to lubricate. Particularly in a saddle-type vehicle such as a motorcycle, the engine speed is high. Therefore, an improvement in the reliability of lubrication of the valve is required.

For example, Patent Document 1 discloses a lubricating structure of a valve. In the lubricating structure, an oil supply passage (50) is formed inside the walls of the cylinder block (14), the cylinder head (15), and the head cover (16). Lubricating oil passes through the passages (61, 62, 63) formed in the wall of the head cover (16). Lubricating oil is discharged from the opening (64) connected to the passage (63), and the lubricating oil is supplied to the intake valve (41).

Meanwhile, Patent Document 2 also discloses a valve lubrication structure. In the lubricating structure, a bolt (108) for mounting the cam holder (70) together with the cylinder head (27) and the cylinder block (26) to the crankcase (25) is disclosed. An oil passage (109) is formed between the bolt (108) and the cylinder head (27) and the cylinder block (26). The oil passage (109) communicates with an oil sump (110) formed in the first support wall (70a) of the cam holder (70). The camshaft (65) is provided with a central oil passage (111) communicating with the oil sump (110). An oil ejection hole (112) is formed in the intake side cam (68). The oil ejection hole (112) communicates with the central oil passage (111) and extends in the radial direction. An oil ejection hole (113) is formed in the exhaust side cam (69). The oil ejection hole (113) communicates with the central oil passage (111) and extends in the radial direction. Lubricating oil ejected from the oil ejection holes (112, 113) is supplied to the intake valve stem end (60a).

JP 2012-246839 A JP 2008-82311 A

However, in the lubricating structure of Patent Document 1, since the oil supply passage (50) is formed inside the walls of the cylinder block (14), the cylinder head (15), and the head cover (16), the manufacturing cost increases. End up. In particular, a plurality of passages (61, 62, 63) extending in different directions must be formed in the head cover (16), which complicates the structure of the head cover (16) and increases the manufacturing cost. is there.

On the other hand, in the lubricating structure of Patent Document 2, the oil passage (109) is formed using the hole through which the bolt (108) is passed, thereby suppressing an increase in manufacturing cost. Moreover, since the lubricating oil is injected and the valve is lubricated by the injection holes (112, 113) provided in the intake side cam (68) and the exhaust side cam (69), an increase in manufacturing cost is suppressed. . That is, Patent Document 2 aims to provide a lubrication structure that suppresses an increase in manufacturing cost by eliminating the process of forming a complicated oil passage in the head cover.

However, as in Patent Document 2, in a structure in which lubricating oil is injected to lubricate the valve, it is not easy to make the lubricating oil reach the valve with high accuracy. In particular, when the engine speed is low, the oil pump discharge amount decreases, and the injection amount injected from the injection hole decreases. For this reason, it is difficult to allow the lubricating oil to reach the valve with high accuracy. Therefore, a large amount of oil is required to sufficiently supply the lubricating oil to the valve, which is inefficient.

In addition, in Patent Document 2, an oil passage and an oil reservoir are formed in the cam holder, an oil passage is formed in the camshaft, and an oil injection port is formed in the cam. Therefore, the manufacturing cost increases. Further, in Patent Document 2, the cam holder is formed separately from the cylinder head in order to easily form an oil passage and an oil reservoir in the cam holder. For this reason, the number of parts is increased, and the manufacturing cost may increase from this point.

An object of the present invention is to stabilize a valve in a straddle-type vehicle engine, while suppressing an increase in manufacturing cost, by a compactly formed lubrication passage regardless of engine state or change in viscosity of lubricating oil. Is to lubricate.

An engine for a saddle-ride type vehicle according to an aspect of the present invention includes a cylinder, a cylinder head, a combustion chamber, an intake port, an exhaust port, an intake valve, an exhaust valve, an intake valve support, and an exhaust. A valve support portion, an intake valve pressing portion, an exhaust valve pressing portion, a camshaft, a cam holder, and a lubricating oil passage are provided. The cylinder head is attached to the cylinder. The combustion chamber is formed by a cylinder and a cylinder head. The intake port is connected to the combustion chamber. The exhaust port is connected to the combustion chamber. The intake valve opens and closes the flow of intake air flowing from the intake port to the combustion chamber. The exhaust valve opens and closes the flow of exhaust flowing from the combustion chamber to the exhaust port. The intake valve support is provided in the cylinder head and supports the intake valve. The exhaust valve support portion is provided in the cylinder head and supports the exhaust valve. The intake valve pressing unit pushes the intake valve toward the combustion chamber. The exhaust valve pressing unit presses the exhaust valve toward the combustion chamber. The camshaft moves the intake valve pressing portion and the exhaust valve pressing portion. The cam holder supports the cam shaft and is formed integrally with the cylinder head. The lubricating oil passage supplies lubricating oil for lubricating the intake valve or the exhaust valve.

Lubricating oil passage has a cylinder head mounting portion, a protruding portion, a guide portion, and an extending portion. The cylinder head mounting portion is formed in the cam holder, and has a bolt hole through which a bolt for fixing the cylinder head to the cylinder is passed and the lubricating oil flows. The protruding portion is formed integrally with the cam holder, protrudes from the cylinder head mounting portion toward the intake valve or the exhaust valve, and guides lubricating oil flowing from the upper end of the bolt hole. The guide portion is formed separately from the protruding portion and extends toward the intake valve or the exhaust valve. The guide portion includes a lubricating oil receiving portion that receives the lubricating oil flowing through the protruding portion below the protruding portion. The extending portion extends downward from the lower end portion of the protruding portion toward the lubricating oil receiving portion at a position separated from the cylinder head mounting portion.

The inventors of the present application first considered suppressing an increase in manufacturing cost without forming an oil passage in the cylinder head cover. In addition, the inventor considered to suppress an increase in manufacturing cost by using the bolt hole as a passage for supplying the lubricating oil to the valve while integrating the cam holder and the cylinder head. In order to stably supply lubricating oil to the valve even when the engine is running at a low speed while suppressing an increase in manufacturing cost, instead of injecting the lubricating oil to the valve and supplying it to the valve, the valve is started from the upper end of the bolt hole. The inventor has studied to guide the lubricant well to Further, the inventor has considered that the flow of the lubricating oil can be made smooth while simplifying the passage structure through which the lubricating oil flows by reducing the number of parts when guiding the lubricating oil. In addition, in the space surrounded by the cylinder head and the cylinder head cover, there are a large number of parts such as a camshaft and a rocker arm. Therefore, it is necessary to form a passage for guiding lubricating oil in a compact manner.

When the bolt hole is used as a passage for the lubricating oil, the lubricating oil flows from the lower side to the upper side of the bolt hole, and the direction in which the lubricating oil flows from the upper end of the bolt hole toward the valve changes. Therefore, when receiving the lubricating oil flowing from the upper end of the bolt hole by a separate member from the cam holder, the connection structure with the separate member is complicated, and there is a possibility that the lubricating oil may not flow smoothly. In addition, depending on the connection structure with the separate member or the attachment structure of the separate member, there is a possibility that the compactness of the space surrounded by the cylinder head and the cylinder head cover cannot be secured.

Therefore, the inventor first considered extending the protrusion formed integrally with the cam holder from the vicinity of the bolt hole to the valve. Then, the lubricating oil can be received with a simple structure without obstructing the flow of the lubricating oil flowing from the upper end of the bolt hole, and the member for attaching the protrusion is not required, so the lubricating passage is compact. Can be formed.

However, the inventor faced challenges. It has been found that when the protruding portion is formed integrally with the cam holder and the protruding portion is extended to a position where the valve is disposed, the protruding portion becomes an obstacle and it becomes very difficult to attach and detach the valve. If the cam holder and the protrusion are formed integrally while the cam holder is separated from the cylinder head, the bolts can be easily attached and detached by removing the cam holder. However, this may increase the manufacturing cost as described above.

The inventor has devised, the cam holder and the cylinder head are integrally formed to suppress the manufacturing cost, and only the base end portion of the protrusion is formed integrally with the cam holder, and the guide is formed separately from the protrusion. It was devised to guide the lubricating oil to the valve by the part. Thereby, the detachability of a valve | bulb is securable by removing only a guide part. Further, the lubricating oil flowing from the upper end of the bolt hole can be smoothly supplied to the valve while maintaining the compactness of the lubricating passage.

Here, the inventor further considered the delivery of the lubrication part from the protruding part to the guide part. Even if the inventor forms the protruding portion and the guide portion separately, the lubricant oil receiving portion of the guide portion is disposed below the protruding portion, so that the lubricant can be stably transferred from the protruding portion to the guide portion. It was found that the performance can be improved. In addition, the compactness of the lubrication passage can be improved by overlapping the protrusion and the guide.

However, the inventor faced new challenges here. The cause of the problem is the viscosity of the lubricating oil. For example, when the engine temperature is low, such as immediately after starting the engine, the temperature of the lubricating oil is also low. If the temperature of the lubricating oil is low, the viscosity of the lubricating oil will increase. When the viscosity of the lubricating oil is low, the lubricating oil is easy to flow, but when the viscosity of the lubricating oil is high, the lubricating oil is difficult to flow. Therefore, the inventors have found that when the engine temperature is low, the lubricating oil cannot be successfully transferred from the protruding portion to the lubricating oil receiving portion. That is, when the viscosity of the lubricating oil is high, the protruding portion may be formed integrally with the cam holder, and the lubricating oil does not flow well to the lubricating oil receiving portion, and as shown by the arrow A1 in FIG. 25, the protruding portion (71) It has been found that it flows along the lower surface of itself and flows into the cylinder head mounting portion (46).

Therefore, the inventor has further devised. An extending portion extending downward from the lower end portion of the protruding portion toward the lubricating oil receiving portion was formed at a position spaced apart from the cylinder head mounting portion in the protruding portion. Thereby, even when the viscosity of the lubricating oil is high, the lubricating oil can be smoothly transferred from the extending portion to the lubricating oil receiving portion.

The protruding portion may extend perpendicular to the cylinder head mounting portion. The extending portion may extend vertically from the protruding portion. In this case, it is easy to ensure the dimension of the extending portion because the protruding portion extends vertically. That is, when the dimension of the extending portion is short, the lubricating oil is unlikely to drip, but the lubricating oil can flow smoothly by ensuring the dimension of the extending portion. Thereby, the lubricating oil can be stably supplied to the valve while maintaining compactness in a limited space.

The guide part may not be in contact with the extending part. In this case, the lubricating oil can be supplied while forming the projecting portion and the guide portion compactly.

The protrusion may have a groove that communicates with the bolt hole. The engine may include a lid. The lid portion overlaps with the base end of the groove portion from above in a plan view of the groove portion, and does not overlap the tip end of the groove portion. In this case, it is possible to suppress the overflow of the lubricating oil flowing from the lower side to the upper side and change the flowing direction appropriately. Further, since the lid portion does not overlap the tip of the groove portion, it is possible to achieve a compact size. Furthermore, since the flow of the lubricating oil can be appropriately changed, the lubricating oil can be smoothly flowed even if the lid portion does not overlap all of the groove portions.

The lid portion may overlap from the upper side to the whole end portion of the groove portion from the base end to the tip end in a plan view of the groove portion. The lid portion may be formed integrally with the guide portion. In this case, it is possible to prevent the lubricating oil from spilling by covering the whole while utilizing a shape that can form the guide portion compactly.

¡When viewed from the axial direction of the cylinder head, the protruding portion does not have to overlap the intake valve and the exhaust valve. In this case, since the protruding portion does not interfere with the valve, the valve can be easily attached and detached.

When viewed from the axial direction of the cylinder head, at least a part of the guide portion may overlap the intake valve or the exhaust valve. In this case, the lubricating oil can be stably supplied to the valve by the guide portion.

The guide part may be attached to the cam holder by a bolt for fixing the cylinder head to the cylinder. In this case, the guide portion can be attached to the cam holder using a bolt for fixing the cylinder head to the cylinder. Further, the guide portion can be easily arranged near the cam holder. Thereby, manufacturing cost can be held down.

The guide portion may further include an upper surface portion and a side surface portion. The upper surface portion may be attached to the upper surface of the cam holder. The side surface portion may extend downward from the upper surface portion. The lubricating oil receiving portion may extend in a direction away from the cam holder from the lower end portion of the side surface portion. In this case, when the guide portion is disposed on the upper side of the cylinder axis in a vehicle-mounted state where the cylinder axis is inclined, the lubricating oil can be stably received by the side surface portion and the lubricating oil receiving portion.

The groove part may be opened in the horizontal direction in a vehicle-mounted state. In this case, even if the protruding portion is disposed on the upper side of the cylinder axis in the on-vehicle state, it can be dropped onto the lubricating oil receiving portion by flowing the lubricating oil in the horizontal direction.

The lubricating oil receiving part may extend from the lower end part of the side part in a direction approaching the cam holder. In this case, the lubricating oil can be stably received by the lubricating oil receiving portion even when the intake valve or the exhaust valve, the projecting portion, and the guide portion are disposed below the axis of the cylinder head in a vehicle-mounted state.

The groove may be opened obliquely downward in the vehicle-mounted state. In this case, the lubricating oil can be efficiently dropped from the groove.

A straddle-type vehicle according to another aspect of the present invention includes the engine described above.

According to the present invention, in a straddle-type vehicle engine, the valve is stabilized regardless of the engine state or the change in the viscosity of the lubricating oil by the compactly formed lubricating passage while suppressing an increase in manufacturing cost. Can be lubricated.

It is a side view of a saddle riding type vehicle. It is a figure which shows the internal structure of an engine. It is an enlarged view which shows the internal structure of a cylinder head. It is an enlarged view which shows the internal structure of a cylinder head. It is a figure which shows the internal structure of an engine. It is a perspective view of a cylinder head in the state where a head cover was removed. It is a perspective view of a cylinder head in the state where the 1st guide part and the 2nd guide part were removed. It is the figure which looked at the cylinder head of the state where the head cover was removed from the cylinder axial direction. It is a side view of a cylinder head in the state where a head cover was removed. It is a top view of a cylinder head in the state where a valve mechanism was removed. It is a schematic diagram which shows the path | route of the lubricating oil of an engine. It is a perspective view which shows the circumference | surroundings of a 1st valve | bulb. It is a perspective view which shows the circumference | surroundings of the intake valve of the state from which the 1st guide part was removed. It is a side view which shows the circumference | surroundings of an intake valve. It is a perspective view which shows the circumference | surroundings of an intake valve. It is a perspective view of a 1st guide part. It is an enlarged view which shows the circumference | surroundings of a 1st extending | stretching part. It is an enlarged view which shows the circumference | surroundings of the 1st extending | stretching part in the state in which the saddle riding type vehicle leans backward. It is a perspective view showing the circumference of the 2nd valve in the state where the 2nd guide part was removed. It is a perspective view showing the circumference of the 2nd valve in the state where the 2nd guide part was attached. It is a perspective view showing the circumference of the 2nd valve in the state where the 2nd guide part was attached. It is a side view which shows the circumference | surroundings of a 2nd valve | bulb. It is a front view which shows the circumference | surroundings of a 2nd valve | bulb. It is a perspective view of the 2nd guide part. It is a figure explaining the subject of a related technique.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a side view of the saddle riding type vehicle 1. In the following description, front, rear, left, and right mean front, rear, left, and right as viewed from a rider who has boarded the saddle riding type vehicle 1. The saddle riding type vehicle 1 is a so-called sports type vehicle. The saddle riding type vehicle 1 includes a fuel tank 2, a seat 3, an engine 4, and a vehicle body frame 5.

The fuel tank 2, the seat 3, and the engine 4 are supported by the vehicle body frame 5. The fuel tank 2 is disposed in front of the seat 3. The engine 4 is disposed below the fuel tank 2.

The saddle riding type vehicle 1 includes a head pipe 6, a front fork 7, a front wheel 8, a handle 9, and a headlight unit 10. The head pipe 6 is disposed in front of the fuel tank 2. The front fork 7 includes a steering shaft 15 and a suspension 16. The head pipe 6 supports the steering shaft 15 so as to be rotatable. The suspension 16 is connected to the lower part of the steering shaft 15.

The front wheel 8 is rotatably supported by the front fork 7. The handle 9 is connected to the upper part of the steering shaft 15. The headlight unit 10 is disposed in front of the head pipe 6.

The saddle riding type vehicle 1 includes a swing arm 11 and a rear wheel 12. The swing arm 11 extends rearward from the vehicle body frame 5. The swing arm 11 is connected to the vehicle body frame 5 so as to be swingable up and down. The rear wheel 12 is rotatably supported on the rear part of the swing arm 11.

FIG. 2 is a diagram showing an internal configuration of the engine 4. The right side in FIG. 2 corresponds to the front of the vehicle. In the following description, the front, rear, left, right, up and down directions in the engine 4 mean front, rear, left, right, up and down directions based on the vehicle-mounted state of the engine 4.

The engine 4 includes a cylinder unit 13 and a crankcase 14. The cylinder axis Ax1 of the cylinder unit 13 is arranged to be inclined with respect to the vertical direction. The cylinder axis Ax1 extends obliquely upward and forward. The inclination angle of the cylinder axis Ax1 with respect to the vertical direction is larger than 0 ° and smaller than 90 °. The inclination angle of the cylinder axis Ax1 with respect to the vertical direction may be larger than 0 ° and smaller than 45 °.

The crankcase 14 is disposed below the cylinder unit 13. The crankcase 14 is connected to the lower part of the cylinder unit 13 and extends rearward.

The cylinder unit 13 includes a cylinder head 17, a cylinder 18, and a head cover 19. The cylinder head 17 is disposed above the cylinder 18. The head cover 19 is disposed above the cylinder head 17. The cylinder 18 is disposed above the crankcase 14. FIG. 3 is an enlarged view showing the internal configuration of the cylinder head 17. As shown in FIG. 3, the cylinder head 17 includes a combustion chamber 21, an intake port 22 connected to the combustion chamber 21, and an exhaust port 23 connected to the combustion chamber 21.

The cylinder head 17 is provided with an intake valve 24 and an exhaust valve 25. The cylinder head 17 includes an intake valve support 171 and an exhaust valve support 172. The intake valve support 171 supports the intake valve 24. The exhaust valve support 172 supports the exhaust valve 25. The intake valve support 171 and the exhaust valve support 172 are formed integrally with the cylinder head 17. The intake valve 24 opens and closes the flow of intake air flowing from the intake port 22 to the combustion chamber 21. The exhaust valve 25 opens and closes the flow of exhaust flowing from the combustion chamber 21 to the exhaust port 23.

FIG. 4 is an enlarged view showing the internal configuration of the cylinder head 17. As shown in FIG. 4, a first valve spring 26 is attached to the intake valve 24. The first valve spring 26 urges the intake valve 24 in a direction in which the intake valve 24 closes the intake port 22. The first valve spring 26 is held by a first retainer 27. A first stem end 28 protrudes from the first retainer 27.

A second valve spring 29 is attached to the exhaust valve 25. The second valve spring 29 urges the exhaust valve 25 in a direction in which the exhaust valve 25 closes the exhaust port 23. The second valve spring 29 is held by the second retainer 30. A second stem end 31 protrudes from the second retainer 30.

FIG. 5 is a diagram showing an internal configuration of the engine 4. As shown in FIGS. 4 and 5, a valve mechanism 32 is accommodated in the cylinder unit 13. The valve operating mechanism 32 is a mechanism for opening and closing the intake valve 24 and the exhaust valve 25. The valve operating mechanism 32 employs an SOHC (Single OverHead Camshaft) type mechanism.

FIG. 6 is a perspective view of the cylinder head 17 with the head cover 19 removed. FIG. 7 is a perspective view of the cylinder head 17 in a state in which a first guide portion and a second guide portion which will be described later in FIG. 6 are removed. FIG. 8 is a view of the cylinder head 17 with the head cover 19 removed as viewed from the direction of the cylinder axis Ax1. FIG. 9 is a side view of the cylinder head 17 with the head cover 19 removed.

The valve operating mechanism 32 includes a camshaft 33 for driving the intake valve 24 and the exhaust valve 25. The camshaft 33 extends in the vehicle width direction. The cam shaft 33 includes a first cam 34 and a second cam. The first cam 34 and the second cam 35 are arranged side by side in the axial direction of the camshaft 33.

As shown in FIG. 4, the valve mechanism 32 includes a first rocker shaft 36 and a first rocker arm 37. The first rocker arm 37 is supported by the first rocker shaft 36 so as to be swingable about the first rocker shaft 36. The first rocker arm 37 is provided so that the intake valve 24 can operate.

An intake valve pressing portion 38 is provided at the tip of the first rocker arm 37. The front end of the intake valve pressing portion 38 faces the first stem end 28 of the intake valve 24.

When the first rocker arm 37 is swung by the first cam 34, the intake valve pressing portion 38 pushes down the first stem end 28 of the intake valve 24 toward the combustion chamber 21. As a result, the intake valve 24 is pushed down to open the intake port 22. When the intake valve 24 is not pushed down by the first rocker arm 37, the intake valve 24 is pushed up by the first valve spring 26 to close the intake port 22.

The valve mechanism 32 includes a second rocker shaft 41 and a second rocker arm 42. The second rocker arm 42 is supported by the second rocker shaft 41 so as to be swingable about the second rocker shaft 41. The second rocker arm 42 is provided so that the exhaust valve 25 can operate. An exhaust valve pressing portion 43 is provided at the tip of the second rocker arm 42. The distal end of the exhaust valve pressing portion 43 faces the second stem end 31 of the exhaust valve 25.

When the second rocker arm 42 is swung by the second cam 35, the exhaust valve pressing portion 43 pushes down the second stem end 31 of the exhaust valve 25 toward the combustion chamber 21. As a result, the exhaust valve 25 is pushed down to open the exhaust port 23. When the exhaust valve 25 is not pushed down by the second rocker arm 42, the exhaust valve 25 is pushed up by the second valve spring 29 and the exhaust port 23 is closed.

The cylinder head 17 includes a cam holder 44. The cylinder head 17 includes an attachment surface 45 to which the head cover 19 is attached. The cam holder 44 protrudes above the mounting surface 45. The cam holder 44 is formed integrally with the cylinder head 17. The cam holder 44 supports the cam shaft 33.

The cam shaft 33 is supported so as to be rotatable with respect to the cam holder 44. The first rocker shaft 36 is rotatably supported with respect to the cam holder 44. The second rocker shaft 41 is supported so as to be rotatable with respect to the cam holder 44.

FIG. 10 is a top view of the cylinder head 17 with the valve mechanism 32 removed. As shown in FIG. 10, the cam holder 44 includes a first cylinder head mounting portion 46, a second cylinder head mounting portion 47, a third cylinder head mounting portion 48, and a fourth cylinder head mounting portion 49. The first cylinder head mounting portion 46 and the second cylinder head mounting portion 47 are arranged in the front-rear direction. The third cylinder head mounting portion 48 and the fourth cylinder head mounting portion 49 are arranged in the front-rear direction. The first cylinder head mounting portion 46 and the third cylinder head mounting portion 48 are arranged in the left-right direction. The second cylinder head mounting portion 47 and the fourth cylinder head mounting portion 49 are arranged in the left-right direction.

The first cylinder head mounting portion 46 is provided with a first bolt hole 51. The second cylinder head mounting portion 47 is provided with a second bolt hole 52. The third cylinder head mounting portion 48 is provided with a third bolt hole 53. The fourth cylinder head mounting portion 49 is provided with a fourth bolt hole 54. Each bolt hole 51-54 extends in the direction of the cylinder axis Ax 1 and passes through the cylinder unit 13.

The bolts 55-58 shown in FIG. 8 are passed through the bolt holes 51-54. Specifically, the first bolt 55 is passed through the first bolt hole 51. A second bolt 56 is passed through the second bolt hole 52. A third bolt 57 is passed through the third bolt hole 53. A fourth bolt 58 is passed through the fourth bolt hole 54. The cylinder unit 13 is fixed to the crankcase 14 by these bolts 55-58.

As shown in FIG. 5, a sprocket 59 is attached to the camshaft 33. The sprocket 59 is engaged with the cam chain 60. The rotation of the crankshaft 61 is transmitted to the camshaft 33 through the cam chain 60, whereby the camshaft 33 rotates.

The cylinder unit 13 is disposed so as to be inclined with respect to the vertical direction so that the cylinder axis Ax1 extends obliquely upward in the vehicle-mounted state. For this reason, as shown in FIG. 2, the intake valve 24 is disposed above the cylinder axis Ax1. The exhaust valve 25 is disposed below the cylinder axis Ax1.

Next, the lubrication structure of the intake valve 24 and the exhaust valve 25 will be described. FIG. 11 is a schematic diagram showing the route of the lubricating oil of the engine 4. As shown in FIG. 11, engine 4 includes an oil pan 62, an oil pump 63, and a lubricating oil passage 60. The oil pump 63 is driven by the rotation of the crankshaft 61. The oil pump 63 sucks the lubricating oil from the oil pan 62 and supplies it to the lubricating oil passage 60.

The lubricant passage 60 includes a first lubricant passage 601, a second lubricant passage 602, a third lubricant passage 603, and a fourth lubricant passage 604. The first lubricating oil passage 601 supplies lubricating oil for lubricating the intake valve 24 and the exhaust valve 25. The second lubricating oil passage 602 supplies lubricating oil for lubricating the crankshaft 61. The third lubricating oil passage 603 supplies lubricating oil for lubricating the main shaft 88 and the drive shaft 89. The fourth lubricating oil passage 604 is connected to the oil pump 63. The first lubricant passage 601, the second lubricant passage 602, and the third lubricant passage 603 are connected to the fourth lubricant passage 604, respectively. The lubricating oil discharged from the oil pump 63 flows through the fourth lubricating oil passage 604 to each of the first lubricating oil passage 601, the second lubricating oil passage 602, and the third lubricating oil passage 603.

Hereinafter, the first lubricating oil passage 601 will be described in detail. The first lubricating oil passage 601 includes a first bolt hole 51 of the first cylinder head mounting portion 46 and a second bolt hole 52 of the second cylinder head mounting portion 47. The fourth lubricating oil passage 604 communicates with the first bolt hole 51 and the second bolt hole 52. Lubricating oil is supplied from the fourth lubricating oil passage 604 to the first bolt hole 51 and the second bolt hole 52.

The first lubricating oil passage 601 includes a first protruding portion 71 and a first guide portion 66. FIG. 12 is a perspective view showing the periphery of the intake valve 24. FIG. 13 is a perspective view showing the periphery of the intake valve 24 with the first guide portion 66 removed. FIG. 14 is a side view showing the periphery of the intake valve 24. FIG. 15 is a perspective view showing the periphery of the intake valve 24.

The first projecting portion 71 and the first guide portion 66 are disposed above the cylinder axis Ax1 together with the intake valve 24. The first projecting portion 71 is formed integrally with the cam holder 44 and projects from the cam holder 44 toward the intake valve 24. The first projecting portion 71 projects from the top of the first cylinder head mounting portion 46. The first protrusion 71 extends perpendicular to the first cylinder head mounting portion 46. The first protrusion 71 guides the lubricating oil flowing from the upper end of the first bolt hole 51.

In the side view, the first protrusion 71 is located above the intake valve 24. The first protrusion 71 overlaps the first rocker arm 37 in a side view. The first protrusion 71 does not overlap the intake valve 24 when viewed from the cylinder axis Ax1 direction. As shown in FIG. 8, the first protrusion 71 is located on the side of the intake valve 24. The first protrusion 71 is located above the first retainer 27 of the intake valve 24.

A first groove 65 is provided in the first protrusion 71. The first groove portion 65 is formed on the top surface of the first protrusion 71. The first groove portion 65 extends rearward and obliquely upward from the first bolt hole 51 and is bent toward the side. The first groove 65 extends toward the intake valve 24. That is, the 1st groove part 65 is opened in the horizontal direction in the vehicle-mounted state. The 1st groove part 65 is opened in the left-right direction in the vehicle-mounted state.

The first groove 65 communicates with the first bolt hole 51. The first bolt hole 51 is open at the top surface of the cam holder 44 and is closed by the first guide portion 66 and the head portion 67 of the first bolt 55. The lubricating oil flows through the gap between the first bolt hole 51 and the first bolt 55 and reaches the cam holder 44 of the cylinder head 17. The lubricating oil passes through the first groove portion 65, is guided by the first guide portion 66, and is supplied to the intake valve 24.

The first guide portion 66 is a separate body from the cam holder 44. That is, the first guide portion 66 is a separate body from the first protrusion 71. The first guide portion 66 is attached to the cam holder 44. The first guide portion 66 is fixed to the cam holder 44 by a first bolt 55 and a third bolt 57. The first guide portion 66 connects the first cylinder head mounting portion 46 and the third cylinder head mounting portion 48. The first guide portion 66 extends toward the intake valve 24. A part of the first guide portion 66 overlaps the first protrusion 71 in plan view. FIG. 16 is a perspective view of the first guide portion 66. As shown in FIG. 16, the first guide portion 66 has a bent plate shape. The first guide portion 66 includes a first upper surface portion 72, a first lid portion 85, a first side surface portion 73, and a first lubricating oil receiving portion 74.

The first upper surface portion 72 is attached to the upper surface of the cam holder 44. The first upper surface portion 72 has a flat plate shape. The first upper surface portion 72 includes a first hole 721, a second hole 722, and a third hole 723. The first bolt 55 is passed through the first hole 721. A third bolt 57 is passed through the second hole 722. The third hole 723 is located between the first hole 721 and the second hole 722. As shown in FIG. 7, the cam holder 44 is provided with a first guide fixing hole 75 between the first bolt hole 51 and the third bolt hole 53. A first fixing bolt 76 shown in FIG. 7 is passed through the third hole 723 and the first guide fixing hole 75.

The first lid portion 85 is formed integrally with the first guide portion 66. The first lid portion 85 protrudes from the first upper surface portion 72. The first lid portion 85 extends in a direction parallel to the upper surface of the first upper surface portion 72. The first lid portion 85 overlaps the base end of the first groove portion 65 from above in the plan view of the first groove portion 65, and does not overlap the tip end of the first groove portion 65. The base end of the first groove portion 65 is a portion that communicates with the first bolt hole 51. The distal end of the first groove portion 65 is a portion opposite to the base end in the lubricating oil path in the first groove portion 65.

The first side surface portion 73 extends downward from the first upper surface portion 72. The first side surface portion 73 extends to a position below the first projecting portion 71. The first lubricating oil receiving portion 74 protrudes from the lower end portion of the first side surface portion 73 in the horizontal direction. That is, the first lubricating oil receiving portion 74 protrudes rearward from the lower end portion of the first side surface portion 73. Specifically, the first lubricating oil receiving portion 74 projects rearward and obliquely upward from the lower end portion of the first side surface portion 73. The first lubricating oil receiver 74 overlaps a part of the first protrusion 71 in plan view.

The first lubricating oil receiving portion 74 receives the lubricating oil from the first groove portion 65 below the first projecting portion 71. The first protruding portion 71 includes a first extending portion 77 that protrudes downward toward the first lubricating oil receiving portion 74. The first extending portion 77 extends vertically from the first protruding portion 71. At a position separated from the first cylinder head mounting portion 46, it extends downward from the lower end portion of the first projecting portion 71 toward the first lubricating oil receiving portion 74. The first guide part 66 is not in contact with the first extending part 77. FIG. 17 is an enlarged view showing the periphery of the first extending portion 77. The first lubricating oil receiving part 74 is arranged to receive the lubricating oil dripping from the first extending part 77. The first lubricating oil receiving portion 74 is disposed below the first extending portion 77. That is, the first lubricating oil receiving portion 74 overlaps the first extending portion 77 in plan view.

The first extending portion 77 has a shape that tapers downward. In the in-vehicle state, the lowest point of the first extending portion 77 is located immediately above the first lubricating oil receiving portion 74. The first extending portion 77 includes a bottom portion 771 and an inclined portion 772. In the in-vehicle state, the bottom 771 is located immediately above the first lubricant receiving portion 74. In the in-vehicle state, the bottom 771 includes the lowest point of the first extending portion 77. The inclined portion 772 is provided at a position farther from the cam holder 44 than the bottom portion 771. The inclined portion 772 is inclined from the upper portion of the first extending portion 77 toward the bottom portion 771. The inclined portion 772 extends from a position that does not overlap the first lubricant receiving portion 74 in plan view to a position that overlaps the first lubricant receiving portion 74 in plan view.

As shown in FIG. 18, the first extension is performed so that the lubricating oil is supplied to the first lubricating oil receiving portion 74 even when the cylinder axis Ax1 is parallel to the vertical direction by tilting the saddle riding type vehicle backward. The lowest point of the portion 77 is set. That is, the lowest point of the first extending portion 77 is located immediately above the first lubricating oil receiving portion 74 in a state where the cylinder axis Ax1 is parallel to the vertical direction.

The first lubricating oil receiving portion 74 extends from the lower end portion of the first side surface portion 73 in a direction away from the cam holder 44. The first lubricating oil receiving portion 74 extends obliquely upward. As viewed from the direction of the cylinder axis Ax1, the first lubricant receiving portion 74 overlaps the intake valve 24. Specifically, the first lubricating oil receiving portion 74 overlaps the first retainer 27 when viewed from the direction of the cylinder axis Ax1. The first lubricating oil receiving portion 74 overlaps the first protruding portion 71 when viewed from the direction of the cylinder axis Ax1. The first lubricating oil receiving portion 74 overlaps the end portion of the first groove portion 65 when viewed from the cylinder axis Ax1 direction.

The first lubricating oil receiving portion 74 is disposed from a position below the first extending portion 77 to a position above the first retainer 27. The first lubricating oil receiving portion 74 is inclined downward toward a position above the first retainer 27. The first lubricating oil receiving portion 74 receives the lubricating oil dropped from the first extending portion 77 and guides it toward the first retainer 27.

The first lubricating oil receiving portion 74 is disposed in the first retainer 27 so that the lubricating oil is dropped on a portion located above the center of the first retainer 27. In other words, the first lubricating oil receiving portion 74 is disposed in the first retainer 27 so that the lubricating oil is dropped on a portion located closer to the cam holder 44 than the center of the first retainer 27.

FIG. 19 is a perspective view showing the periphery of the exhaust valve 25 with the second guide portion 69 removed. As shown in FIG. 19, the cylinder head 17 includes a second protrusion 78. The second projecting portion 78 and the second guide portion 69 are disposed below the cylinder axis Ax1 together with the exhaust valve 25. The second projecting portion 78 is formed integrally with the cam holder 44 and projects from the cam holder 44 toward the exhaust valve 25. The second projecting portion 78 projects from the top of the second cylinder head mounting portion 47. The second projecting portion 78 extends perpendicular to the second cylinder head mounting portion 47. The second protrusion 78 guides the lubricating oil flowing from the upper end of the second bolt hole 52.

20 and 21 are perspective views showing the periphery of the exhaust valve 25. FIG. FIG. 22 is a side view showing the periphery of the exhaust valve 25. FIG. 23 is a front view showing the periphery of the exhaust valve 25. The second protrusion 78 is positioned above the exhaust valve 25 in a side view. The second protrusion 78 overlaps the second rocker arm 42 in a side view. The second protrusion 78 does not overlap the exhaust valve 25 when viewed from the direction of the cylinder axis Ax1. The second projecting portion 78 is located on the side of the exhaust valve 25. The second projecting portion 78 is located above the second retainer 30 of the exhaust valve 25.

The second protrusion 78 includes a second groove 68 that communicates with the second bolt hole 52. The second groove 68 is formed on the top surface of the second protrusion 78. The second groove 68 extends obliquely downward from the second bolt hole 52. The second groove 68 extends toward the exhaust valve 25. The second groove 68 is opened obliquely downward in the in-vehicle state.

The second guide portion 69 is attached to the cam holder 44. The second bolt hole 52 opens at the top surface of the cam holder 44 and is closed by the second guide portion 69 and the head portion 70 of the second bolt 56. The lubricating oil flows through the gap between the second bolt hole 52 and the second bolt 56 and reaches the cam holder 44 of the cylinder head 17. The lubricating oil passes through the second groove portion 68, is guided by the second guide portion 69, and is supplied to the exhaust valve 25.

The second guide portion 69 is a separate body from the cam holder 44. The second guide portion 69 is a separate body from the first guide portion 66. The second guide portion 69 is fixed to the cam holder 44 by the second bolt 56 and the fourth bolt 58. The second guide portion 69 connects the second cylinder head mounting portion 47 and the fourth cylinder head mounting portion 49. The second guide portion 69 extends toward the exhaust valve 25. FIG. 24 is a perspective view of the second guide portion 69. As shown in FIG. 24, the second guide portion 69 has a bent plate shape. The second guide portion 69 includes a second upper surface portion 79, a second lid portion 86, a second side surface portion 80, and a second lubricating oil receiving portion 81.

The second upper surface portion 79 is attached to the upper surface of the cam holder 44. The second upper surface portion 79 has a flat plate shape. The second upper surface portion 79 includes a first hole 791, a second hole 792, and a third hole 793. The second bolt 56 is passed through the first hole 791. The fourth bolt 58 is passed through the second hole 792. The third hole 793 is located between the first hole 791 and the second hole 792. As shown in FIG. 7, the cam holder 44 is provided with a second guide fixing hole 82 between the second bolt hole 52 and the fourth bolt hole 54. The second fixing bolt 83 shown in FIG. 7 is passed through the third hole 793 and the second guide fixing hole 82.

The second lid portion 86 is formed integrally with the second guide portion 69. The second lid portion 86 extends in a direction parallel to the upper surface of the second upper surface portion 79. In plan view of the second groove portion 68, the second lid portion 86 overlaps with everything from the base end to the tip end of the second groove portion 68 from above. The base end of the second groove portion 68 is a portion communicating with the second bolt hole 52. The distal end of the second groove portion 68 is a portion opposite to the base end in the lubricating oil path in the second groove portion 68.

The second side surface portion 80 extends downward from the second upper surface portion 79. The second side surface portion 80 faces the end portion of the second groove portion 68. The second side surface portion 80 covers the end portion of the second groove portion 68 in the horizontal direction. The second lubricating oil receiving portion 81 protrudes from the lower end portion of the second side surface portion 80. The second lubricating oil receiving portion 81 protrudes from the lower end portion of the second side surface portion 80 in a direction approaching the cam holder 44.

The second lubricating oil receiving portion 81 receives the lubricating oil from the second groove portion 68 below the second projecting portion 78. In plan view, the second lubricant receiving portion 81 overlaps the second projecting portion 78. The second projecting portion 78 includes a second extending portion 84 that projects downward toward the second lubricating oil receiving portion 81.

The second extending portion 84 extends vertically from the second projecting portion 78. The second guide portion 69 is not in contact with the second extending portion 84. The second extending portion 84 extends downward from the lower end portion of the second projecting portion 78 toward the second lubricating oil receiving portion 81 at a position separated from the second cylinder head mounting portion 47. The second extending portion 84 is disposed so as to be biased toward the side surface closer to the exhaust valve 25 among the pair of side surfaces of the second projecting portion 78. One side surface of the second extending portion 84 extends downward from the side surface closer to the exhaust valve 25. The other side surface of the second extending portion 84 is located immediately below the second groove portion 68.

The second lubricating oil receiving portion 81 is disposed below the second extending portion 84 and is disposed so as to receive the lubricating oil dripping from the second extending portion 84. That is, the second lubricating oil receiving portion 81 overlaps the second extending portion 84 in plan view.

In the in-vehicle state, the lowest point of the second extending portion 84 is located immediately above the second lubricating oil receiving portion 81. Further, even when the cylinder axis Ax1 becomes parallel to the vertical direction by tilting the saddle type vehicle backward, the bottom of the second extending portion 84 is supplied so that the lubricating oil is supplied to the second lubricating oil receiving portion 81. A point is set. That is, the lowest point of the second extending portion 84 is located immediately above the second lubricating oil receiving portion 81 in a state where the cylinder axis Ax1 is parallel to the vertical direction.

The second lubricating oil receiving portion 81 extends from the lower end portion of the second side surface portion 80 in a direction approaching the cam holder 44. The second lubricating oil receiver 81 extends obliquely downward. The second lubricant receiving portion 81 overlaps the exhaust valve 25 when viewed from the direction of the cylinder axis Ax1. Specifically, the second lubricant receiving portion 81 overlaps the second retainer 30 when viewed from the direction of the cylinder axis Ax1.

The second lubricating oil receiving portion 81 is disposed from a position below the second extending portion 84 to a position above the second retainer 30. The second lubricating oil receiving portion 81 is inclined downward toward a position above the second retainer 30. The second lubricating oil receiving portion 81 receives the lubricating oil dropped from the second extending portion 84 and guides it toward the second retainer 30.

The second lubricating oil receiving portion 81 is arranged in the second retainer 30 so that the lubricating oil is dropped on a portion located above the center of the second retainer 30. In other words, the second lubricating oil receiving portion 81 is disposed in the second retainer 30 so that the lubricating oil is dropped on a portion located closer to the cam holder 44 than the center of the second retainer 30.

In the engine 4 according to this embodiment, the lubricating oil is dropped from the first extending portion 77 through the first groove portion 65 through the first groove portion 65 and the end portion of the first projecting portion 71. The dropped lubricating oil is received by the first lubricating oil receiving portion 74 and / or the first side surface portion 73, flows through the first lubricating oil receiving portion 74, and flows from the first lubricating oil receiving portion 74 to the first of the intake valve 24. 1 Drop onto the retainer 27. As a result, the lubricating oil is supplied to the first stem end 28 of the intake valve 24.

Further, the lubricating oil passes from the second bolt hole 52 through the second groove portion 68, passes through the end portion of the second projecting portion 78, and drops from the second extending portion 84. The lubricating oil is received by the second lubricating oil receiving portion 81 and / or the second side surface portion 80, flows through the second lubricating oil receiving portion 81, and the second retainer of the exhaust valve 25 from the second lubricating oil receiving portion 81. Drip on 30. As a result, the lubricating oil is supplied to the second stem end 31 of the exhaust valve 25.

As described above, in the engine 4 according to this embodiment, the lubricating oil can be guided to the intake valve 24 by the first groove portion 65 and the first guide portion 66 of the first projecting portion 71. Accordingly, the lubricating oil can be supplied to the intake valve 24 stably and efficiently. Further, the first projecting portion 71 and the first guide portion 66 can be easily formed as compared with the case where a passage is provided in the head cover 19 or the camshaft 33. Thereby, the increase in manufacturing cost can be suppressed. Further, since the first guide portion 66 is made of sheet metal, the manufacturing cost can be reduced.

The first protrusion 71 does not overlap the intake valve 24 when viewed from the axial direction of the cylinder head 17. For this reason, since the 1st protrusion part 71 does not interfere with the intake valve 24, attachment / detachment of the intake valve 24 is easy.

Lubricating oil drops from the first groove portion 65 to the first lubricating oil receiving portion 74 along the first extending portion 77 of the first projecting portion 71. As a result, the lubricating oil can be stably dropped onto the first lubricating oil receiving portion 74.

When viewed from the axial direction of the cylinder head 17, a part of the first lubricant receiving portion 74 overlaps the intake valve 24. Thereby, the lubricating oil can be dropped accurately from the first lubricating oil receiving portion 74 to the intake valve 24.

The first guide portion 66 is a separate body from the cam holder 44. For this reason, even if the first guide portion 66 is disposed so as to overlap the intake valve 24, the intake valve 24 can be easily attached and detached by removing the first guide portion 66. In addition, since the first guide portion 66 is separate from the cam holder 44, the first guide portion 66 is used by the operator when forming the intake valve support portion 171 and the exhaust valve support portion 172 on the cylinder head 17. Alternatively, interference with the tool can be avoided. Therefore, the workability of the cylinder head 17 can be improved.

The first guide portion 66 is attached to the cam holder 44. For this reason, the first guide portion 66 can be easily disposed near the cam holder 44. Thereby, manufacturing cost can be held down.

The first groove 65 has a groove shape formed on the top surface of the first protrusion 71. For this reason, the process which forms the 1st groove part 65 is easy.

As described above, the effects of the first groove portion 65 and the first guide portion 66 of the first protrusion portion 71 have been described, but the same applies to the second groove portion 68 and the second guide portion 69 of the second protrusion portion 78.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention.

鞍 Saddle-type vehicles include motorcycles, rough terrain vehicles (ALL-TERRAIN VEHICLE), and snowmobiles. The motorcycle includes a scooter and a moped. The motorcycle may include two or more front wheels. Alternatively, the motorcycle may include two or more rear wheels.

The intake valve 24 may be an exhaust valve that opens and closes the exhaust port 23. The exhaust valve 25 may be an intake valve that opens and closes the intake port 22. The number of intake valves 24 is not limited to one, and a plurality of intake valves 24 may be provided. The number of exhaust valves 25 is not limited to one, and a plurality of exhaust valves 25 may be provided. The valve mechanism 32 is not limited to SOHC but may be a DOHC (Double OverHead Camshaft) type mechanism.

One of the first protrusion 71 and the second protrusion 78 may be omitted. One of the first guide part 66 and the second guide part 69 may be omitted.

The first protrusion 71 may overlap the intake valve 24 when viewed from the axial direction of the cylinder head 17. The second protrusion 78 may overlap the exhaust valve 25 when viewed from the axial direction of the cylinder head 17. When viewed from the axial direction of the cylinder head 17, the first guide portion 66 may not overlap the intake valve 24. When viewed from the axial direction of the cylinder head 17, the second guide portion 69 may not overlap the exhaust valve 25.

The first guide part 66 may be integrated with the cam holder 44. The second guide portion 69 may be integrated with the cam holder 44. The 1st groove part 65 may open in directions other than a horizontal direction in a vehicle-mounted state. The second groove portion 68 may open in a direction other than the obliquely downward direction in the vehicle-mounted state.

The first groove portion 65 is not limited to the groove shape, and may be another shape such as a hole. The second groove portion 68 is not limited to the groove shape, and may be another shape such as a hole.

The terms and expressions used here are used for explanation and are not used for limited interpretation. It should be recognized that any equivalents of the features shown and described herein are not excluded and that various modifications within the claimed scope of the invention are permitted. The present invention can be embodied in many different forms. This disclosure should be regarded as providing embodiments of the principles of the invention. The embodiments are described herein with the understanding that the embodiments are not intended to limit the invention to the preferred embodiments described and / or illustrated herein. It is not limited to the embodiment described here. The present invention also encompasses any embodiment that includes equivalent elements, modifications, deletions, combinations, improvements and / or changes that may be recognized by those skilled in the art based on this disclosure. Claim limitations should be construed broadly based on the terms used in the claims and should not be limited to the embodiments described herein or in the process of this application.

17 Cylinder head 24 Intake valve 25 Exhaust valve 33 Camshaft 44 Cam holder 71 First protrusion 78 Second protrusion 66 First guide part 69 Second guide part 77 First extension part 84 Second extension part 74 First lubricating oil receiver Part 81 second lubricating oil receiving part

Claims

A cylinder,
A cylinder head attached to the cylinder;
A combustion chamber formed by the cylinder and the cylinder head;
An intake port connected to the combustion chamber;
An exhaust port connected to the combustion chamber;
An intake valve for opening and closing the flow of intake air flowing from the intake port to the combustion chamber;
An exhaust valve for opening and closing an exhaust flow flowing from the combustion chamber to the exhaust port;
An intake valve support provided on the cylinder head and supporting the intake valve;
An exhaust valve support provided on the cylinder head and supporting the exhaust valve;
An intake valve pressing portion that presses the intake valve toward the combustion chamber;
An exhaust valve pressing portion that presses the exhaust valve toward the combustion chamber;
A camshaft for moving the intake valve pressing portion and the exhaust valve pressing portion;
A cam holder that supports the camshaft and is formed integrally with the cylinder head;
A lubricating oil passage for supplying lubricating oil for lubricating the intake valve or the exhaust valve,
The lubricating oil passage is
A cylinder head mounting portion formed in the cam holder and having a bolt hole through which a bolt for fixing the cylinder head to the cylinder is passed and through which lubricating oil flows;
A protrusion formed integrally with the cam holder, protruding from the cylinder head mounting portion toward the intake valve or the exhaust valve, and guiding lubricating oil flowing from the upper end of the bolt hole;
A lubricating oil receiving portion that receives the lubricating oil flowing through the protruding portion below the protruding portion, and is formed separately from the protruding portion and extends toward the intake valve or the exhaust valve;
In a position separated from the cylinder head mounting portion, an extending portion extending downward from the lower end portion of the protruding portion toward the lubricating oil receiving portion,
Having
Engine for saddle riding type vehicles.
The protrusion extends perpendicular to the cylinder head mounting portion,
The extending portion extends vertically from the protruding portion,
The engine for a saddle riding type vehicle according to claim 1.
The guide part is not in contact with the extending part,
The engine for a saddle riding type vehicle according to claim 1 or 2.
The protrusion has a groove communicating with the bolt hole,
In a plan view of the groove part, the base part of the groove part is overlapped from above, and a lid part that does not overlap the tip end of the groove part is provided.
The engine for the saddle riding type vehicle according to any one of claims 1 to 3.
The protrusion has a groove communicating with the bolt hole,
In the plan view of the groove portion, the groove portion is provided with a lid portion that overlaps from above all the base end to the tip end,
The lid portion is formed integrally with the guide portion.
The engine for the saddle riding type vehicle according to any one of claims 1 to 3.
The protrusion does not overlap the intake valve and the exhaust valve when viewed from the axial direction of the cylinder head,
The engine for a straddle-type vehicle according to any one of claims 1 to 5.
When viewed from the axial direction of the cylinder head, at least a part of the guide portion overlaps the intake valve or the exhaust valve.
The engine for the saddle riding type vehicle according to any one of claims 1 to 6.
The guide portion is attached to the cam holder by a bolt for fixing the cylinder head to the cylinder.
The engine for the saddle riding type vehicle according to claim 1.
The guide portion further includes an upper surface portion attached to the upper surface of the cam holder, and a side surface portion extending downward from the upper surface portion,
The lubricating oil receiving portion extends in a direction away from the cam holder from a lower end portion of the side surface portion;
The engine for the saddle riding type vehicle according to any one of claims 1 to 8.
In the in-vehicle state in which the axis of the cylinder head is inclined with respect to the vertical direction, the intake valve or the exhaust valve, the protruding portion, and the guide portion are arranged above the axis of the cylinder head. To be
The engine for saddle riding type vehicles according to claim 7.
The protrusion has a groove communicating with the bolt hole,
The groove is open in the horizontal direction in the in-vehicle state,
The engine for a saddle riding type vehicle according to claim 10.
The guide portion further includes an upper surface portion attached to the upper surface of the cam holder, and a side surface portion extending downward from the upper surface portion,
The lubricating oil receiving portion extends in a direction approaching the cam holder from a lower end portion of the side surface portion,
The engine for the saddle riding type vehicle according to any one of claims 1 to 8.
In an in-vehicle state in which the axis of the cylinder head is inclined with respect to the vertical direction, z the intake valve or the exhaust valve, the protrusion, and the guide are below the axis of the cylinder head Placed in the
The engine for saddle riding type vehicles according to claim 12.
The protrusion has a groove communicating with the bolt hole,
The groove portion is opened obliquely downward in the in-vehicle state,
The engine for saddle riding type vehicles according to claim 13.
A straddle-type vehicle comprising the engine according to any one of claims 1 to 14.