ASSEMBLY STRUCTURE OF A DRIVE MACHINE AND VEHICLE

Abstract

A mounting structure of a drive machine (41) in which a cylinder head (43), on which an oil control valve unit (61) designed to control an oil pressure in a variable valve timing device (110) of the drive machine (41) is installed, is mounted on a crankcase (42), wherein an outer wall of the cylinder head (43) is formed with an opening (83) into which the oil control valve unit (61) is partially inserted, and wherein a mating surface (88) of the cylinder head (43) and the crankcase (42) is fastened by at least a pair of bolts (87) spaced apart from each other via the opening (83).

Description

Technical field

[0001] The present disclosure relates to an assembly structure of a drive machine and a vehicle. background

[0002] In the past, engines in which a variable valve timing device is installed to control the valve timing of an intake and an exhaust valve in accordance with the engine's operating state, for high performance, low fuel consumption, and low exhaust emissions, have been increasingly used. One such engine is known in which hydraulic pressure is applied to the variable valve timing device by means of an oil control valve unit installed on an outer surface of a cylinder (see, for example, Patent Specification 1). The variable valve timing device is supplied with oil by the oil control valve unit, and the valve timing is adjusted by changing the rotational phase of a camshaft relative to a crankshaft on either the forward or retracting side.

[0003] Patent specification 1: JP 5 345 448 B2

[0004] In such a drive engine, an opening, into which an oil control valve unit is partially inserted, is formed in an outer wall of the cylinder head, and the strength of the outer wall of the cylinder head is reduced by the amount of the opening. Therefore, it is desirable to firmly attach the cylinder head to a crankcase and ensure a secure connection between the crankcase and the cylinder head in order to dampen or prevent vibration noise.

[0005] Patent specification 2: DE 600 05 102 T2

[0006] Patent specification 2 relates to an internal combustion engine with a valve characteristic control mechanism for changing the operating characteristics of at least one inlet valve and one exhaust valve, which is driven by a cam provided on a camshaft, and a control device for controlling the pressure of working oil which is to be supplied to the valve characteristic control mechanism.

[0007] Patent specification 3: DE 112013006598 T5

[0008] Patent specification 3 relates to an oil injection abnormality determination device of an internal combustion engine, which determines the presence or absence of an abnormality of an oil injection or oil jet in the internal combustion engine, and to a control device which controls the internal combustion engine in accordance with its determination results.

[0009] Patent specification 4: DE 601 27 506 T2

[0010] Patent specification 4 relates to a valve actuation control system for an engine, comprising a first valve actuation characteristic changing mechanism designed to change the valve lift, and a second valve actuation characteristic changing mechanism designed to change the valve timing.

[0011] Patent specification 5: DE 10 2010 014 798 A1

[0012] Patent specification 5 relates to small vehicles, such as motorcycles, with an oil control valve for adjusting the hydraulic pressure of a valve actuation mechanism or other hydraulically actuated mechanisms.

[0013] Patent specification 6: US 7,308,882 B2

[0014] Patent specification 6 relates generally to an engine oil supply system configured to be integrated into a gearbox. More specifically, patent specification 6 relates to an engine oil supply system suitable for use with a motorcycle and configured to supply oil to a gearbox and other components besides the gearbox itself.

[0015] Patent specification 7: JP 2005- 330 857 A

[0016] Patent specification 7 discloses that a hydraulic variable valve control mechanism of an engine is equipped with a hydraulic actuator provided at one end of an intake camshaft, and with an oil control valve located on the outside of a timing chain and near a tensioner, which adjusts the pressure of the oil supplied to the hydraulic actuator. Summary

[0017] It is at least one of the objectives of the present disclosure to provide an assembly structure for a drive machine that can ensure a secure fastening of a cylinder head and a crankcase without hindering the installation of the oil control valve, and to provide a vehicle.

[0018] According to one aspect of the embodiments of the present disclosure, an assembly structure of a drive machine is provided in which a cylinder head, on which an oil control valve unit configured to control an oil pressure in a variable valve timing device of the drive machine is installed, is mounted on a crankcase, wherein an outer wall of the cylinder head is formed with an opening into which the oil control valve unit is partially inserted, and wherein a mating surface of the cylinder head and the crankcase is fastened by at least one pair of bolts spaced apart from each other across the opening.

[0019] The cylinder head and crankcase are secured by a pair of bolts in such a way that opening the cylinder head is avoided. It is possible to ensure the secure attachment of the cylinder head and crankcase without hindering the installation of the oil control valve assembly via the pair of bolts. Even if an opening is formed in the outer wall of the cylinder head, the cylinder head's strength is not significantly reduced, and the attachment strength of the cylinder head and crankcase remains high, thus reducing vibration noise. Brief description of the drawings

[0020] The attached drawings include: Fig. 1 a left side view of a motorcycle according to the present embodiment, Fig. 2A and Fig. 2B Illustrative views of an installation structure of an oil control valve unit according to a comparative example, Fig. 3 a perspective view of the circumference of a drive machine according to the present embodiment, Fig. 4 a right side view of a front half of the motorcycle according to the present embodiment, Fig. 5 a rear view of the circumference of the drive machine according to the present embodiment, Fig. 6A and Fig. 6B Schematic views of a control valve according to the present embodiment, Fig. 7 a perspective view of an oil control valve unit according to the present embodiment, Fig. 8A to 8D Top views of a valve housing according to the present embodiment, Fig. 9A to 9E Cross-sectional views of the valve housing according to the present embodiment, Fig. 10A and Fig. 10B Installation views of an oil control valve according to the present embodiment, Fig. 11A and Fig. 11B Partial cross-sectional views of a cylinder head according to the present embodiment, Fig. Figures 12A to 12C are illustrative views of a mounting structure for the cylinder head and a crankcase according to the present embodiment. Fig. 13 a perspective view showing a flow path structure of a drive machine according to the present embodiment, Fig. 14 a side view showing the flow path structure of the drive machine according to the present embodiment, Fig. 15 a schematic view of a variable valve timing system according to the present embodiment, and Fig. 16A and Fig. 16B Views showing an example of an assembly process of a vehicle body frame according to the present embodiment. Detailed description of the embodiments

[0021] The following describes embodiments in detail with reference to the accompanying drawings. An example is given here in which an installation structure of an oil control valve unit according to the present embodiment is applied to a sports motorcycle, but the application is not limited to this and can be modified accordingly. For example, the oil control valve unit can be used on other types of motorcycles. Fig. Figure 1 is a left side view of the motorcycle according to the present embodiment. In the respective subsequent drawings, the front of the vehicle body is indicated by an arrow FR, the rear of the vehicle body is indicated by an arrow RE, the left side of the vehicle body is indicated by an arrow L, and the right side of the vehicle body is indicated by an arrow R.

[0022] As in Fig. Figure 1 shows the motorcycle 1 formed by mounting various components, such as a drive unit 41 and an electrical system, onto a double-tube vehicle body frame 10 made of cast aluminum. Main frames 12 of the vehicle body frame 10 branch off to the left and right from a head tube 11 and extend to the rear. The pair of left and right main frames 12 are curved to wrap around the rear of the drive unit 41, and the rear of the drive unit 41 is supported by a body frame 15 at the rear of the main frames 12. Subframe 13 (see Fig. 3) of the vehicle body frame 10 branch off to the left and right from the head tube 11 and extend downwards, and a front side of the drive engine 41 is supported on lower sections of the pair of left and right subframes 13.

[0023] A portion of a front side section of the main frame 12 is a tank rail 14, and a fuel tank 21 is installed on the tank rail 14. A rear side section of the main frame 12 is designed as the body frame 15, and a pivot point 17, which pivotally supports a pivot arm 18, is formed in an up-down direction at a substantially central position on the body frame 15. A seat rail (not shown) and a rearward-extending rearward brace 16 are provided on an upper section of the body frame 15. A driver's seat 23 and a pillion seat or passenger seat 24, which is connected to the fuel tank 21, are provided on the seat rail.

[0024] The vehicle body frame 10 is mounted with various covers as external parts of the vehicle body. For example, a front half of the vehicle body is covered with a front cowl 26, a side surface of the vehicle body frame is covered with a side cowl 27. The seat rail is covered with a rear cowl 28, and a front lower part of the drive unit 41 is covered with a lower cowl 29. A pair of right and left front forks 32 are supported in the head tube 11 so that they can be steered via a steering shaft (not shown). A front suspension for the front wheel is provided in the front fork 32. A front wheel 33 is rotatably supported by lower sections of the front forks 32, and the top of the front wheel 33 is covered with a front fender 34.

[0025] The pivot arm 18 extends rearward from the pivot arm pivot point 17. A rear suspension 36 for a rear wheel is provided between the pivot arm 18 and the body frame 15. The rear suspension 36 has one end supported by an upper end face of the body frame 15 and the other end connected to the pivot arm 18 via a suspension link 37. A rear wheel 38 is rotatably supported by a rear end of the pivot arm 18. The drive motor 41 and the rear wheel 38 are coupled via a deceleration mechanism, and power or energy is transmitted from the drive motor 41 to the rear wheel 38 via the deceleration mechanism. The top of the rear wheel 38 is covered by a rear fender 39, which is provided on a rear section of the rear cowl 28.

[0026] The drive motor 41 is modified by attaching a cylinder head 43 (see Fig. 3) on a crankcase 42, in which a crankshaft (not shown) is housed, a parallel four-cylinder drive engine or the like. The drive engine 41 is supported by the vehicle body frame 10 in such a way that the rigidity of the entire vehicle body is ensured. Air is drawn into the drive engine 41 through an inlet pipe (not shown), and the air and fuel are mixed and supplied to a combustion chamber by a fuel injection device. Exhaust gas after combustion is discharged by a silencer 44 via an exhaust pipe (not shown) that extends rearward along a right-hand side surface of the drive engine 41.

[0027] For the drive machine 41, which is designed as described above, a variable valve timing control system is used, which controls the actuation timing of an inlet valve in accordance with an operating state of the drive machine. An oil control valve unit 61 (see Fig. 3) is installed on an outer surface of the drive unit 41 and hydraulic pressure for the variable valve timing system is controlled by the oil control valve unit 61. Power is transmitted from the crankshaft to the variable valve timing system via a timing chain and the intake valve is moved at drive timings controlled by the oil control valve unit 61.

[0028] The oil control valve unit 61 is partially inserted into an opening formed in an outer wall of the cylinder head 43, and an internal flow path of the oil control valve unit 61 is connected to an internal flow path of the cylinder head 43. The oil control valve unit 61 is bolted to an installation surface of the cylinder head 43 with bolts or screws such that the oil control valve unit 61 is pressed firmly against the installation surface. However, a drive engine vibration occurs in the cylinder head 43 in a cylinder axial direction, and this drive engine vibration reduces the bond strength between the oil control valve unit 61 and the installation surface of the cylinder head 43.

[0029] For example, as in a comparative example from Fig. Figure 2A shows the oil control valve unit 61 screwed onto the cylinder head 43 at two positions in the front-to-back direction of the vehicle. However, as in Fig. In Figure 2B, the oil control valve unit 61 is shown screwed to the cylinder head 43 at only one position in the cylinder axial direction. Therefore, a moment acts on a free end of the oil control valve unit 61 due to the drive engine vibration in the cylinder axial direction, and the oil control valve unit 61 wobbles with one screw point acting as a pivot point. Therefore, in the present embodiment, the oil control valve unit 61 is screwed to the cylinder at two positions along the cylinder axial direction (see Figure 2B). Fig. 3).

[0030] By forming an opening 83 (see Fig. 11A) in the outer wall of the cylinder head 43 for the oil control valve unit 61, the strength of the outer wall of the cylinder head 43 is reduced and the drive engine vibration is increased. Therefore, vibration noise increases and it is difficult to ensure a secure bond between the oil control valve unit 61 and an opening edge of the outer wall of the cylinder head 43. Therefore, in the present embodiment, a mating surface 88 of the cylinder head 43 and the crankcase 42 is fastened by a pair of bolts spaced apart across the opening, and the reduction in the strength of the cylinder head 43 is dampened or avoided by utilizing the strength of the crankcase 42 (see Fig. 12C).

[0031] The installation structure of the oil control valve unit according to the present embodiment is described below with reference to Fig. 3 to 6 described. Fig. Figure 3 is a perspective view of the circumference of the drive machine according to the present embodiment. Fig. Figure 4 is a right side view of a front half of the motorcycle according to the present embodiment. Fig. Figure 5 is a rear view of the environment of the drive machine according to the present embodiment. Fig. 6A and Fig. Figure 6B shows schematic views of a control valve according to the present embodiment. Fig. For the sake of simplicity, descriptions 3 to 6B omit various covers as external parts of the vehicle body.

[0032] As in Fig. 3 and Fig. As shown in Figure 4, the drive unit 41 is supported by the vehicle body frame 10, and a radiator 47 is installed in front of the drive unit 41. The drive unit 41 is mounted with the cylinder head 43 on the crankcase 42. The pair of left and right main frames 12 extend rearward from the head tube 11 above the cylinder head 43, and the pair of left and right subframes 13 extend downwards from the head tube 11 in front of the cylinder head 43. The front side section of the vehicle body frame 10 is forked into the main frames 12 and the subframes 13 such that an installation space 49 for the oil control valve unit 61 is provided on one side (right side) of the cylinder head 43.

[0033] In this case, the subframes 13 are designed to support a front side of the drive unit 41. The subframes 13 support a front side of the cylinder head 43 and have a substantially triangular shape, in which the width of the subframe 13 gradually widens in a front-to-back direction from a support position 19 of the drive unit 41 to the cylinder head tube 11. In contrast to a structure in which a lower section of the drive unit 41 is supported by the subframes 13, the cylinder head 43, which is provided on the upper section of the drive unit 41, is supported by the subframes 13 in such a way that the width of the subframe 13 is not widened in the front-to-back direction, and that the installation space 49 of the oil control valve unit 61 is ensured on one side of the cylinder head 43.

[0034] On one side of the drive unit 41, the oil control valve unit 61 is installed in the installation space 49 between the main frame 12 and the subframe 13 such that the space between the radiator 47 and the oil control valve unit 61 is blocked by the subframe 13. Accordingly, the heat from the radiator 47 is shielded by the subframe 13, which is part of the vehicle body frame 10, thus preventing a deterioration of the operating characteristics of the oil control valve unit 61 due to a temperature increase. Furthermore, the oil control valve unit 61 is positioned between the main frame 12 and the subframe 13 in such a way that it is protected from flying stones in front of the vehicle body frame.

[0035] Since the front of the oil control valve unit 61 is blocked by the subframe 13, the influence of heat from the radiator 47 is avoided. However, it is difficult for the airflow to strike or collide with the oil control valve unit 61. Therefore, with respect to a pair of front and rear IN cam axes O1 and EX cam axes O2 of the cylinder head 43, the subframe 13 is designed to extend through a front face of the EX cam axes O2, and the main frame 12 is designed to extend through a rear face of the IN cam axes O1, thus widening the installation space 49 of the oil control valve unit 61. The installation space 49 is so wide that it is difficult to retain heat within it, and the ambient temperature is therefore reduced.

[0036] Furthermore, a gearbox or transmission is housed in the crankcase 42, and the drive engine housing 42 is provided with a gearbox cover 45 to protect the gearbox from one side. The gearbox cover 45 bulges outwards to the side, and the oil control valve unit 61 is installed above the gearbox cover 45. The oil control valve unit 61 is surrounded by the gearbox cover 45, the main frame 12, and the subframe 13, and the space enclosed by the gearbox cover 45, the main frame 12, and the subframe 13 is efficiently used as the installation space 49. Accordingly, the oil control valve unit is protected from flying stones in front of the vehicle body by the subframe 13, and the oil control valve unit 61 is protected from flying stones under the vehicle body by the gearbox cover 45.

[0037] An upper section of the gearbox cover 45 is designed such that the interval or distance to the oil control valve unit 61 widens towards the front. The upper section of the gearbox cover 45 is inclined downwards towards the front, increasing the vertical distance between the upper section of the gearbox cover 45 and the oil control valve unit 61. The gearbox cover 45 and the oil control valve unit 61 are spaced apart, allowing the installation space 49 for the oil control valve unit 61 to be wider. This makes it more difficult to retain heat in the installation space 49 and thus reduces the ambient temperature. In this way, the installation space 49, with a sufficient area on a side surface of the drive unit 41, is ensured by the main frame 12, the subframe 13, and the gearbox cover 45.

[0038] The pair of left and right main frames 12 extends obliquely rearward from the head tube 11, and the distance or planar distance of the main frames 12 is reduced or narrowed at the rear of the installation space 49 of the oil control valve unit 61 (see in particular Fig. 5) The oil control valve unit 61 is installed above the transmission cover 45. Accordingly, the airflow at the rear of the oil control valve unit 61 is not obstructed by the main frame 12 and the transmission cover 45. Viewed from the rear, the oil control valve unit 61 is exposed. Therefore, heat flows from the installation space 49 to the rear during driving, thus efficiently cooling the oil control valve unit 61.

[0039] A radiator hose 48 extends from the radiator 47 to the rear, and the oil control valve unit 61 is installed above the radiator hose 48 on the side surface of the engine 41. Cooling water is supplied from the radiator 47 to the engine 41 through the radiator hose 48, and the oil control valve unit 61 is cooled by the cooling water in the radiator hose 48. Because the radiator hose 48 runs directly beneath the oil control valve unit 61, the oil control valve unit 61 is protected from flying stones under the vehicle body by the radiator hose 48. Since the radiator hose 48 is made of rubber or a similar material, it is difficult for it to be damaged by flying stones.

[0040] As in Fig. 3 and Fig. As shown in Figure 5, the oil control valve unit 61 overlaps the main frame 12 when viewed from above and overlaps the subframe 13 and the transmission cover 45 when viewed from the front to the rear. The oil control valve unit 61 overlaps the main frame 12 when viewed from above, so that the main frame 12 acts as a rain cover, preventing damage to the oil control valve unit 61 from rainwater. The oil control valve unit 61 overlaps the subframe 13 and the transmission cover 45 when viewed from the front to the rear, so that the oil control valve unit 61 is protected from flying stones in front of and under the vehicle body, and the effect of the subframe 13 on shielding the radiator 47 from heat is increased.

[0041] The oil control valve unit 61 is installed, viewed from the front-to-rear direction, on a side further inward than all of the transmission cover 45, the main frame 12, and the subframe 13. The oil control valve unit 61 is protected from impact in the event of a vehicle rollover and from other external impacts by the transmission cover 45, the main frame 12, and the subframe 13. The oil control valve unit 61 is mounted in the vehicle body frame 10, viewed from the front-to-rear direction, in such a way as to avoid increasing the overall width of the vehicle body. It should be noted that the inner side, viewed from the front-to-rear direction, can be a side further inward than the outermost surfaces of the transmission cover 45, the main frame 12, and the subframe 13.

[0042] The oil control valve unit 61 is screwed to the installation space 49 of the cylinder head 43 at two positions by a pair of bolts or screws 81. As described above, since the drive motor vibration in the drive motor 41 is generated in the cylinder axial direction (see Fig. 2) The vibration of the oil control valve unit 61 caused by the drive motor vibration is dampened or prevented by the pair of bolts 81, which are spaced apart from each other in the cylinder axial direction. Furthermore, the oil control valve unit 61 includes a cylindrical control valve 62 for controlling the valve timing on an air supply side between the pair of bolts 81 in a horizontal position.

[0043] As in Fig. Figure 6A shows the control valve 62, a spool valve designed in a cylindrical shape, divided into a solenoid side, which houses a solenoid 66, and a valve spool side, which houses a valve spool 67. The solenoid 66 is a cylindrical, conductive wire coil and, when energy is supplied, generates a magnetic field, which advances and retracts the valve spool 67, which is connected to the iron core 68 on an inner side of the solenoid 66. By advancing and retracting the valve spool 67, the oil supply in the control valve 62 is switched to a feed chamber or a retraction chamber, thereby adjusting the valve timing of the inlet valve.

[0044] The control valve 62 tends to generate heat by supplying energy to the solenoid 66, and the operating characteristics are deteriorated due to the temperature rise of the solenoid 66. Therefore, in the present embodiment, the side of the solenoid 66 of the control valve 62 faces the rear. Since the solenoid 66 is spaced apart from the radiator 47 (see Fig. 3), which is a heat source, prevents the magnet 66 from heating up due to the radiator 47 and avoids the deterioration of the operating characteristics of the control valve 62 due to a temperature increase of the magnet 66. Furthermore, the axis of the magnet 66 of the control valve 62 is preferably oriented horizontally or obliquely upwards towards the rear.

[0045] For example, in a comparative example from Fig. As shown in Figure 6B, when the axis of the solenoid 66 of the control valve 62 is oriented obliquely downwards towards the rear, foreign substances such as impurities C, which are generated on the side of the valve spool 67, move towards the side of the solenoid 66 due to their own weight in the oil. Therefore, the foreign substances, such as impurities C, can be deposited on the side of the solenoid 66. Therefore, in the present embodiment, which is shown in Fig. As shown in 6A, the axis of the magnet 66 is horizontal or angled upwards towards the back (horizontal in Fig. 6A). This makes it difficult for foreign substances such as impurities C, which are generated on the side of the valve slide 67, to enter the side of the magnet 66 and makes it less likely that the magnet 66 will be damaged.

[0046] The following describes the installation structure of the oil control valve unit with reference to Fig. 7 to 12 described. Fig. Figure 7 is a perspective view of the oil control valve unit according to the present embodiment.

[0047] Fig. Figures 8A to 8D are top views of a valve housing according to the present embodiment. Fig. Figures 9A to 9E are cross-sectional views of the valve housing according to the present embodiment. Fig. 10A and Fig. Figure 10B shows installation views of the oil control valve according to the present embodiment. Fig. 11A and Fig. Figure 11B shows partial cross-sectional views of the cylinder head according to the present embodiment. Fig. Figures 12A to 12C are illustrative views of a mounting structure for the cylinder head and crankcase according to the present embodiment. Fig. 8 is the magnetic side, represented by a two-dotted dashed line to simplify descriptions.

[0048] As in Fig. Figure 7 shows a valve housing 63 of the oil control valve unit 61 integrally formed with a valve housing 65, into which the valve spool (not shown) is inserted at an upper section of the housing body 64, in which a plurality of oil passages are formed. The main housing body 64 is used by being inserted into the outer wall of the cylinder head 43 (see Figure 7). Fig. 11A) and an outer surface of the housing body 64 is fitted with an O-ring 82 to seal a gap or space between the outer wall of the cylinder head 43 and the housing body 64. With the O-ring 82 acting as a boundary, the side of the housing body 64 is received in the cylinder 43 and the side of the valve housing 65 protrudes outwards from the cylinder 43.

[0049] As in Fig. 7 and Fig. Figures 8A to 8D show a pair of mounting holes 71a, 71b for the bolts 81 (see Fig. 10A) is designed to penetrate the housing body 64, and four oil ports (oil passages) 72a to 72d are provided to the control valve 62. The respective oil ports are a supply port 72a, a feed angle port 72b, a retraction port 72c, and a drain port 72d, and are connected to an inner side of the valve housing 65 in which the valve spool is received. When the connection state of the oil ports 72a to 72d is switched by actuating the control valve 62, oil is supplied to the feed chamber or the retraction chamber of the valve timing device.

[0050] The oil enters the supply port 72a at the center of the housing body 64, and the oil, filtered through the filter 73 of the oil supply port 72a, is fed to the control valve 62. When the control valve 62 switches, the supply port 72a communicates with either the feed port 72b or the retract port 72c, and the drain port 72d communicates with either the feed angle port 72b or the retract port 72c. Accordingly, oil is supplied from the supply port 72a to the feed chamber or the retract chamber of the variable valve timing device, and oil is discharged from the other port through the drain port 72d.

[0051] As in Fig. Figures 9A to 9D show that the oil ports 72a to 72d in the housing body 64 are formed by a lower surface 74, which is located on a wall surface of the drive unit 41, and extend directly to the valve housing 65. Therefore, the pressure loss due to the through-flow design in the housing body 64 is reduced, the oil flow in each of the oil ports 72a to 72d is uniform, and the response of the variable valve timing device is improved. A drain port 72d is partially cut out, and the oil can be discharged through a cutout 75 even when the lower surface 74 of the housing body 64 is mounted on the wall surface of the drive unit 41.

[0052] As in Fig. Figure 9E shows that the oil ports 72a to 72d and the mounting holes 71a, 71b are formed in the housing body 64 by ensuring sufficient thickness on an inner side of an annular groove 76 of the O-ring 82. Furthermore, the oil ports 72a to 72d are arranged between straight lines L2 and L3, which pass through the centers of the mounting holes 71a, 71b and are perpendicular to a straight line L1 that connects the centers of the pair of mounting holes 71a, 71b. Since the valve housing 65 is positioned on an inner side of the pair of mounting holes 71a, 71b (see Figure 9E), the oil ports 72a to 72d are arranged between straight lines L2 and L3, which pass through the centers of the mounting holes 71a, 71b and are perpendicular to a straight line L1 that connects the centers of the pair of mounting holes 71a, 71b. Fig. 8D), the oil ports 72a to 72d communicate with the inside of the valve housing 65 in a direction perpendicular to the lower surface of the housing body 64.

[0053] All of the oil ports 72a to 72d and the mounting holes 71a, 71b of the main body of the valve housing 64 are formed parallel to a demolding direction or tool removal direction during the casting of the valve housing 63. Accordingly, the outer form, which constitutes an outer shape of the valve housing 63, and the casting pins, which form the oil ports 72a to 72d and the mounting holes 71a, 71b of the valve housing 63, can be removed in the same direction during casting, and the number of machining steps can be reduced to improve productivity. In this way, each of the oil ports 72a to 72d of the oil control valve unit 61 is formed in a straight shape, taking into account not only the pressure loss of the oil but also the number of manufacturing steps.

[0054] As in Fig. 8D and Fig. Figure 9B shows a pair of hubs or round projections 77, where the mounting holes 71a, 71b are open, at two positions between which the valve housing 65 is to be inserted. The hubs 77 not only reinforce the mounting holes 71a, 71b, but also reinforce the valve housing 65 to increase its strength. Furthermore, a hub or round projection 78 is shown, on which a bracket 79 (see Figure 9B) is attached. Fig. 7) of magnet 66 (see Fig. 7) is integrally formed in a hub 77 to increase strength. Accordingly, the housing body 64, the valve housing 65 and the hubs 77, 78 are integrally formed, which can increase the fastening strength of the magnet 66 to the valve housing 63.

[0055] As in Fig. As shown in Figure 10A, the oil control valve unit 61 is screwed to the cylinder head 43 from the sides by the pair of bolts 81. In this case, an outer wall 85 of the cylinder head 43 is open in a circular shape, and the valve housing 63 is partially inserted into an opening. An inner wall 86 (see Figure 10A) Fig. 10B) of the cylinder head 43 is designed with an installation surface 80 (see Fig. 10B), on which the valve housing 63, inserted through an opening, is installed. Oil passages and screw holes (not shown) are formed in the installation surface 80 at positions corresponding to the oil connections 72a to 72d and the mounting holes 71a, 71b of the valve housing 63.

[0056] If the mounting holes 71a, 71b (see Fig. 7) of the valve body 63 with the screw holes of the installation surface 80 (see Fig. 10 B) are aligned and screwed in place by the pair of bolts 81, the oil control valve unit 61 is attached to the cylinder head 43. Accordingly, a mating surface of the valve housing 63 and the inner wall 86 (see Fig. 10B) of the cylinder head 43 is sealed to be fluid-tight, and the oil connections 72a to 72c of the housing body 64 communicate with the oil passages of the inner wall of the cylinder head 43. The oil control valve unit 61 is screwed to itself by the pair of bolts 81 above the center of the valve housing 63 in a direction along the cylinder axial direction of the cylinder head 43.

[0057] The cylinder axial direction is the reciprocating motion of a piston in the drive unit 41, and drive vibration is primarily generated in the cylinder axial direction by the reciprocating movement of a piston in the cylinder head 43. Since the facing sections of the oil control valve unit 61 are secured by the pair of bolts 81 in the direction along the cylinder axial direction, vibration of the valve housing 63 due to drive unit vibration in the cylinder axial direction is prevented. Accordingly, the adhesion of the oil control valve unit 61 to the installation surface (see Fig. 10B) of the cylinder head 43 is ensured and the sealing performance of the oil passages is improved by the mating surface of the valve housing 63 and the inner wall 86 of the cylinder head 43.

[0058] More precisely, as in Fig. Figure 10B shows the oil control valve unit 61 screwed to the installation surface 80 of the cylinder head 43 at two positions transversely across the center of the valve housing 63 in the cylinder axial direction. Therefore, even if a moment acts on a free end of the valve housing 83 due to the drive engine vibration in the cylinder axial direction, the vibration of the valve housing 63 due to the moment at both ends in the cylinder axial direction is effectively suppressed. Since the oil control valve unit 61 vibrates integrally with the cylinder head 43, the bond strength of the mating surface of the valve housing 63 and the inner wall 86 of the cylinder head 43 is not reduced by the drive engine vibration.

[0059] Furthermore, in the valve housing 63, the oil connections 72a to 72d are formed closer to the center of the valve housing 63 in the cylinder axial direction than the pair of mounting holes 71a, 71b (see Fig. 9E). Since the valve housing 63 and the installation surface 80 of the cylinder head 43 are in close contact with each other on an inner side of the pair of bolts 81, oil leakage at the mating surface of the valve housing 63 and the cylinder head 43 is prevented. Thus, a high sealing performance can be maintained, even at the oil ports 72a to 72d, where the hydraulic pressure is high. Because oil leakage from the valve housing 63 is prevented and the oil is supplied at sufficient pressure, the response of the variable valve timing device is not impaired.

[0060] With reference to Fig. In 10A, the valve housing 63 is installed on the cylinder head 43 such that the axial direction of the control valve 62 intersects the axial direction of the cylinder. If the axial direction of the valve intersects the vibration of the drive motor in the axial direction of the cylinder, a vibration component of the drive motor vibration in the axial direction with respect to the control valve 62 can be reduced. Thus, operational stability can be improved by preventing faulty operation of the control valve 62 due to the vibration component in the axial direction of the valve. In this case, to efficiently avoid or dampen the vibration component in the axial direction of the valve, it is preferable for the axial direction of the valve to intersect the axial direction of the cylinder at an angle of 45° or more and 90° or less.

[0061] As in Fig. 11A and Fig. Figure 11B shows a chain chamber 84 of a timing chain 56, which transmits power to the variable valve timing device formed in the cylinder head 43 and the crankcase 42 (see Fig. 12B). The outer side of the chain chamber 84 is divided by the outer wall 85 of the cylinder head 43 and the crankcase 42, while the inner side of the chain chamber 84 is divided by the inner wall 86 of the cylinder head 43 and the crankcase 42. As described above, the opening 83 is formed in the outer wall 85 of the cylinder head 43, and the oil control valve assembly 61 is installed such that it is partially inserted into the opening 83 through the inner side of the timing chain 56.

[0062] From an ease of assembly standpoint, installing an element on the inside of the timing chain 56 is not preferable. However, the oil control valve unit 61 is detachably mounted, so it does not obstruct the installation of the timing chain 56. In the case of motorcycle 1 (see Fig. 1) and the like, a chain cover is integrated with the cylinder 43, and it is not possible to remove only the chain cover from the cylinder 43. If an element is installed on the inside of the timing chain 56, the element will obstruct the subsequent installation of the timing chain 56 on the drive motor 41.

[0063] Therefore, in the present embodiment, the oil control valve unit 61 is designed to be detachably mounted, and after the timing chain 56 is mounted on the drive motor 41, the valve housing 63 of the oil control valve unit 61 is inserted into the inner surface of the timing chain 56. Accordingly, no interference occurs during the installation of the timing chain 56, and the dead space on the inner surface of the timing chain 56 is used efficiently. The valve housing 63 of the oil control valve unit 61 is designed to extend through the inner surface of the timing chain 56 such that the oil control valve unit 61 is positioned close to the variable valve timing device.

[0064] Thus, the internal flow path from the main oil channel 53 (see Fig. 14) to the oil control valve unit 61 is long, and the internal flow path from the oil control valve unit 61 to the variable valve timing device on the feed and retract sides is shortened. Although the flow path structure on a downstream side of the oil control valve unit 61 is complex, the pressure loss is minimized by shortening the internal flow path of the oil control valve unit 61 and the variable valve timing device. Thus, oil at a high hydraulic pressure is conveyed from the main oil channel 53 to the oil control valve unit 61, and it is possible to apply the high hydraulic pressure to the variable valve timing device.

[0065] The chain chamber 84 is flared on the inside of the cylinder head 43, and the opening 83, which communicates with the chain chamber 84, is formed in the outer wall 85 of the cylinder head 43. Therefore, the cylinder head 43 and the crankcase 42 are fastened by a pair of bolts 87 to compensate for the stiffness of the outer wall 85 of the cylinder head 43. By increasing the stiffness of the outer wall 85 of the cylinder head 43, vibration noise is reduced, and the sealing performance between the O-ring 82, which is mounted on the outer circumferential surface of the valve housing 63, and the inner circumferential surface of the opening 83 is improved. Furthermore, since the bolts 87 are not provided on the inner wall 86 of the cylinder head 43, the cam housing 89 can be installed on the inner wall 86.

[0066] More precisely, it is like in Fig. 12A and Fig. Figure 12B shows that the mating surface 88 of the cylinder head 43 and the crankcase 42 is fastened by a pair of bolts 87, spaced apart from each other above the opening 83 of the cylinder head 43. The pair of bolts 87 is inserted from above into mounting holes in the cylinder head 43 and screwed into screw holes in the crankcase 42 through the sides of the opening 83. The fastening of the oil control valve unit 61 is not obstructed by the pair of bolts 87. Furthermore, the strength of the cylinder head 43 is improved by fastening the cylinder head 43 to the crankcase 42, ensuring sufficient strength.

[0067] In particular, since the pair of bolts 87 fasten the cylinder head 43 to the crankcase 42 in the cylinder axial direction, the drive engine vibration in the cylinder axial direction is efficiently avoided or dampened by the pair of bolts 87. The pair of bolts 87 is designed in an elongated form that is highly resistant to compressive stress and weak to shear stress. Therefore, shear stress due to drive engine vibration is avoided by the axial direction of the bolts 87, which is aligned with the cylinder axial direction. The outer wall 85 of the cylinder head 43 is provided with a suspension bracket 59, which suspends a front side of the drive engine 41 from the vehicle body frame 10. Although the suspension bracket 59 is located near the opening 83 of the cylinder head 43, the strength of the cylinder head 43 is increased near the opening 83, thereby increasing the fastening strength of the suspension bracket 59 to the vehicle body frame 10.

[0068] As in the Fig. 12A and Fig. As shown in Figure 12C, the valve housing 63 of the oil control valve unit 61 is installed below a sprocket 112 on the inner side of the timing chain 56, with the outlet of the drain port 72d facing downwards in a positioning state. The outlet of the drain port 72d faces the inner circumferential surface of the timing chain 56, and the timing chain 56 is lubricated by the oil dripping from the outlet of the drain port 72d. By supplying the oil to the inner circumferential surface of the timing chain 56, the engagement point of the timing chain 56 and the sprocket 112 is adequately lubricated, and the service life of the timing chain 56 and the sprocket 112 is improved.

[0069] In this case, it is preferable that no element be present in the oil supply path from the outlet of drain port 72d to the timing chain 56. By directly supplying the oil from the outlet of drain port 72d to the inner circumferential surface of the timing chain 56, the quantity of oil supplied to the timing chain 56 can be efficiently ensured. As described above, with a simple structure in which the oil discharged from drain port 72d of the oil control valve unit 61 is used, the timing chain 56 can be well lubricated without providing an associated oil passage, chain ejector, or the like in the cylinder head 43.

[0070] Furthermore, since the valve housing 63 is attached to the inner wall 86 (see Fig. 11A) of the cylinder head 43, the control valve 62 is spaced away from the outer surface of the cylinder head 43. The magnet 66 of the oil control valve unit 61 is thus spaced away from the outer surface of the cylinder head 43 in the transverse direction of the vehicle. Therefore, the magnet 66 of the oil control valve unit 61 does not come into contact with the outer surface of the cylinder head 43, and the temperature rise of the magnet 66 due to heat from the cylinder head 43 is avoided. Thus, the deterioration of the operating characteristics of the oil control valve unit 61 is effectively prevented.

[0071] The flow path structure of the drive machine is described with reference to Fig. 13 and Fig. 14 described. Fig. Figure 13 is a perspective view showing a flow path structure of the drive machine according to the present embodiment. Fig. Figure 14 is a side view illustrating the flow path structure of the drive machine according to the present embodiment. Fig. 13 and Fig. 14 For the sake of simplicity, the outer shape of the elements is represented by a two-dotted dashed line, while the oil passage is represented by a solid line.

[0072] As in Fig. 13 and Fig. Figure 14 shows the main oil channel 53, through which the oil is supplied by an oil pump 52 (see Fig. 15) is forwarded in the crankcase 42. A first oil passage 91, which is directed to the valve system via a crankshaft support (not shown), and a second oil passage 96, which is directed via the oil control valve unit 61 to the feed chamber or retraction chamber of the variable valve timing device 110 (see Fig. 15) are connected to the main oil channel 53. Since the first and second oil passages 91, 96 are branched into two independent hydraulic circuits through the main oil channel 53, a high hydraulic pressure can be ensured without them significantly influencing each other.

[0073] The first oil passage 91 comprises an inner housing passage 92 extending to the side of the cylinder head 43 through the crankshaft bearing, a branch passage 93 extending in the cylinder axial direction, and supply passages 94, 95 for camshafts and a chain tensioner / adjuster, respectively, branched by the branch passage 93. The supply passage 94 for the camshafts extends obliquely forward from a lower end of the branch passage 93 and branches off midway to the bearings of the pair of camshafts. The supply passage 95 for the chain tensioner extends obliquely rearward from an upper end of the branch passage 93. Although the first oil passage 91 branches into different paths, a suitable hydraulic pressure for the chain tensioner and the camshafts is ensured.

[0074] The first half of the second oil passage 96 comprises a bypass passage 97 extending forward from the main oil channel 53, a parallel passage 98 extending parallel to the main oil channel 53 from the center of the bypass passage 97, and a supply passage 99 extending from the parallel passage 98 to the cylinder head 43, bypassing the crankshaft. Since the bypass passage 97 and the parallel passage 98 are located at essentially the same height as the main oil channel 53, a high hydraulic pressure also acts on the bypass passage 97 and the parallel passage 98, similar to that acting on the main oil channel 53. The supply passage 99 is connected to the oil control valve unit 61 at the shortest possible distance from the parallel passage 98 to supply the oil control valve unit 61 with high hydraulic pressure.

[0075] The supply passage 99 of the second oil passage 96 combines a plurality of straight passages and is essentially parallel to the housing inner passage 92 of the first oil passage 91. During the manufacture of the crankcase 42, the supply passage 99 of the second oil passage 96 and the housing inner passage 92 of the first oil passage 91 are formed in the same direction by removing core pins, thereby increasing productivity. The second half of the second oil passage 96 comprises a feed passage 100, directed from the oil control valve unit 61 to the feed chamber, and a retract passage 101, directed from the oil control valve unit 61 to the retract chamber.

[0076] In the feed passage 100 and the retraction passage 101, there is a bend or an angled piece, and a loss of oil curvature occurs in the feed passage 100 and the retraction passage 101. However, the oil control valve unit 61 is located near the variable valve timing device 110 (see Fig. 15) installed and since the feed passage 100 and the retraction passage 101 are short, the pressure loss is avoided or dampened. In the second oil passage 96, the oil of the oil control valve unit 61 is supplied at high hydraulic pressure through the supply passage 99 and the oil can be forwarded from the oil control valve unit 61 to the feed passage 100 or the retraction passage 101 at high hydraulic pressure.

[0077] As described above, the hydraulic pressure for the variable valve timing device 110 (see Fig. 15) The high pressure can be maintained by the second oil passage 96, allowing the variable valve timing device 110 to be operated from a low engine speed to improve driving characteristics. Furthermore, since the first and second oil passages 91, 96 form an independent hydraulic circuit, it is unlikely that the first oil passage 91 of the valve system will be affected by the hydraulic pressure loss of the second oil passage 96 during operation of the variable valve timing device 110. Thus, the lubrication properties of the valve system are improved, and the sensitivity of the variable valve timing device 110 can be enhanced.

[0078] Next, the variable valve timing system will be discussed with reference to Fig. 15 briefly described. Fig. Figure 15 is a schematic view of the variable valve timing system according to the present embodiment. Although the variable valve timing system is described on an intake side, the variable valve timing system can be provided on both the intake and exhaust sides. Fig. For the sake of simplicity, the timing chain is represented by a two-dotted dashed line in Figure 15.

[0079] As in Fig. Figure 15 shows that the variable valve timing system varies the valve timing by changing the rotational phase of the camshafts 55 with respect to a crankshaft (not shown) and includes the hydraulic variable valve timing device 110. Power is transmitted from the crankshafts to the camshafts 55 via the timing chain 56 and the variable valve timing device 110. The variable valve timing device 110 is located at the end of the camshaft 55 and is designed to transmit the power of the camshaft 55 via the oil supplied to it.

[0080] A housing 111 of the variable valve timing device 110 is attached to the pinion 112, to which the timing chain 56 is attached. The pinion 112 is rotatably mounted on an end section of the camshaft 55 together with the housing 111. Furthermore, a rotor 114 with guide vanes 113 is attached to an end section of the camshaft 55 and is mounted within the housing 111 to be rotatable relative to it. A plurality of hydraulic pressure chambers are formed on an inner side of the housing 92, and each guide vane 113 of the rotor 114 is mounted in each hydraulic pressure chamber. Each hydraulic pressure chamber is divided into a feed chamber S1 and a retraction chamber S2 by each guide vane 113.

[0081] The feed chamber S1 and the retraction chamber S2 are designed to communicate with the oil passages formed in the camshaft and cam housing. When the volume of the feed chamber S1 increases due to hydraulic pressure, the rotor 114 is rotated relative to the housing 111 towards the feed side. This rotates the camshaft 55, which is attached to the rotor 114, thus changing the valve timing towards the feed side. Conversely, when the volume of the retraction chamber S2 increases due to hydraulic pressure, the rotor 114 is rotated relative to the housing 111 towards the retraction side. This rotates the camshaft 55, which is attached to the rotor 114, thus changing the valve timing towards the retraction side.

[0082] The variable valve timing device 110 is operated by the hydraulic pressure from the oil control valve unit 61. The oil is pumped from an oil pan 51, via a filter or the like, by the oil pump 52 to the main oil channel 53, and the oil is supplied to the inlet control valve 62 of the oil control valve unit 61 via the crankcase and the internal flow path of the cylinder head. The communication states between the feed port, the retract port, the inlet port, and the drain port of the control valve 62 are then switched, so that the variable valve timing is switched to the feed side or the retract side.

[0083] The first oil passage 91 of the valve system and the second oil passage 96 for the oil control valve unit 61 are located in the crankcase and the cylinder head. Since the second oil passage 96 branches off from the main oil channel 53 and forms a hydraulic circuit independent of the first oil passage 91, the hydraulic pressure of the second oil passage 96 is not used for other hydraulic circuits. Furthermore, because the second oil passage 96 is formed by combining essentially linear passages with minimal curvature, pressure loss in the passage, such as hydraulic curvature loss of the second oil passage 96, is avoided (see Fig. 13).

[0084] Furthermore, since the oil control valve unit 61 is installed near the variable valve timing device 110, the oil can be routed to the area surrounding the variable valve timing device 110 via the second oil passage 96 at high hydraulic pressure. Thus, the oil is supplied to the variable valve timing device 110 by the control valve 62 at high hydraulic pressure, increasing the response speed of the variable valve timing device 110. Additionally, the dead space on the inside of the timing chain 56 can be efficiently utilized in the oil passage of the oil control valve unit 61, and the oil flow within the drive unit is not complicated.

[0085] Next, an assembly process of the vehicle body frame will be described with reference to Fig. 16A and Fig. 16B described. Fig. 16A and Fig. Figure 16B shows an example of the assembly process of the vehicle body frame according to the present embodiment.

[0086] As in Fig. 16A and Fig. Figure 16B shows the gearbox cover 45 extending from a side surface of the drive unit 41, and a rear side section of the vehicle body frame 10 is formed with the body frame 15, which surrounds part of the bulged section of the gearbox cover 45 from the rear (running backwards). Furthermore, the front side section of the vehicle body frame 10 is forked into the main frame 12 and the subframe 13, and space for the oil control valve unit 61 is provided between the main frame 12 and the subframe 13. The oil control valve unit 61 is installed such that the magnet 66 faces the rear of the drive unit 41 in such a way that it is clear of the vehicle body frame 10.

[0087] In this case, the oil control valve unit 61 and the bulged section of the transmission cover 45 are installed in the front-to-rear direction of the vehicle body between a foremost part 15a of the body frame 15 under the transmission cover 45 and a rearmost part 13a of the subframe 13. When the vehicle body frame 10 is mounted vertically downwards from the top of the drive unit 41, moving points L4 and L5 are indicated by the foremost part 15a of the body frame 15 and the rearmost part 13a of the subframe 13. Since the moving points L4 and L5 are located away from the oil control valve unit 61 and the transmission cover 45, the vehicle body frame 10 can be mounted on the drive unit 41 in a position where the oil control valve unit 61 is installed on a lateral surface of the cylinder 43.

[0088] As described above, in the present embodiment the opening 83 of the cylinder head 43 is avoided, and the cylinder head 43 and the crankcase 42 are fastened by the pair of bolts 87. It is possible to ensure the fastening strength of the cylinder head 43 and the crankcase 42 without hindering the fastening of the oil control valve unit 61 by the pair of bolts 87. Even if the opening 83 is formed in the outer wall 85 of the cylinder head 43, the strength of the cylinder head is not significantly reduced, and the fastening strength of the cylinder head 43 and the crankcase 42 remains high, thus reducing vibration noise.

[0089] It should be noted that in the present embodiment, the parallel four-cylinder drive engine is shown as an exemplary drive engine, but the present invention is not limited to this configuration. The design of the drive engine is not specifically limited to, for example, a single-cylinder drive engine, a parallel two-cylinder drive engine, a V-shaped drive engine, a horizontally opposed drive engine, a two-cylinder in-line drive engine, or the like.

[0090] In the present embodiment, the twin-tube frame is exemplary for the vehicle body frame, but the present invention is not limited to this configuration. The vehicle body frame can have any shape that ensures the installation space for the oil control valve unit for the drive motor. For example, the vehicle body frame can be formed by a double-loop frame.

[0091] In the present embodiment, the oil control valve unit is installed on the right side of the drive machine, but the oil control valve unit can be installed on the left side of the drive machine.

[0092] In the present embodiment, the oil control valve unit is installed on one side of the cylinder, but the present invention is not limited to this configuration. The oil control valve unit can be installed on one side of the drive unit. For example, the oil control valve unit can be installed on one side of the drive unit housing.

[0093] In the present embodiment, a slide valve is shown as the oil control valve unit, but the present invention is not limited to this configuration. The oil control valve unit can have any configuration capable of controlling the hydraulic pressure to the variable timing device of the drive machine, and the type of valve is not particularly limited.

[0094] In the present embodiment, the oil control valve unit comprises the intake control valve, but the present invention is not limited to this embodiment. The oil control valve unit can include either the intake control valve or the exhaust control valve.

[0095] In the present embodiment, the oil is supplied to the oil control valve unit via the internal flow path extending from the main oil channel, but the present invention is not limited to this configuration. The oil can be supplied from an external line extending from the main oil channel.

[0096] In the present embodiment, the outlet of the drain port is oriented towards the inner circumferential surface of the timing chain, but the present invention is not limited to this configuration. The outlet of the drain port can be oriented towards the outer circumferential surface of the timing chain, or the outlet of the drain port can be not oriented towards the timing chain.

[0097] In the present embodiment, the oil control valve unit is installed on the cylinder head, but the present invention is not limited to this configuration. The oil control valve unit can be installed on the drive engine. For example, the oil control valve unit can be installed on the crankcase.

[0098] Furthermore, in the present embodiment, the mating surfaces of the cylinder head and the crankcase are fastened by the pair of bolts, but the present invention is not limited to this configuration; the mating surfaces of the cylinder head and the crankcase can be fastened in such a way as to avoid opening the cylinder head. For example, the mating surfaces of the cylinder head and the crankcase can be fastened by three or more bolts.

[0099] In this embodiment, the mating surface of the outer wall of the cylinder head and the outer wall of the crankcase are designed to be fastened, but the present invention is not limited to this embodiment. The mating surface of the inner wall of the cylinder head and the inner wall of the crankcase can also be fastened.

[0100] In the present embodiment, the mating surface of the cylinder head and the crankcase is fastened such that the axial direction of the bolts is aligned in the axial direction, but the present invention is not limited to this embodiment. The mating surface of the cylinder head and the crankcase can be fastened such that the axial direction of the bolts is aligned in a direction that intersects or crosses the axial direction of the cylinder.

[0101] In the present embodiment, the opening in the outer wall of the cylinder head is configured such that the oil control valve unit passes through the inner side of the timing chain, but the present invention is not limited to this configuration. The opening can be configured in the outer wall of the cylinder head such that the oil control valve unit passes through the outer side of the timing chain.

[0102] In the present embodiment, the vehicle body frame can be mounted to the drive unit by attaching the valve housing to the drive unit, such that the magnet faces the rear of the drive unit, but the present invention is not limited to this configuration. The valve housing can be installed in the drive unit such that the magnet faces the front of the drive unit. Since the oil control valve can be attached later, the vehicle body frame can be attached to the drive unit.

[0103] Although the present embodiment has been described, the present embodiment and the modification can be combined in whole or in part as a further embodiment of the present invention.

[0104] The technology of the present disclosure is not limited to the above embodiment and modification, and numerous changes, substitutions, and alternatives can be made without departing from the technical spirit. Furthermore, if the technical spirit of the present invention can be implemented with other methods through technological advances or other equivalent technologies, the present invention can be implemented using those methods. Therefore, the claims cover all realizations encompassed by the technical spirit of the present invention.

[0105] In the present embodiment, although the configuration in which the present invention is applied to a motorcycle is described, the present invention is not limited by this configuration. The present invention can be suitably applied to other vehicles in which the oil control valve unit is installed, for example, to a special machine such as a jet ski, a lawn trimmer, an outboard motor, and the like, and additionally to an automatic four-wheeled vehicle and a buggy-type motor tricycle.

[0106] Features of the above embodiment are summarized below.

[0107] The mounting structure of the drive machine described in this embodiment is a mounting structure of a drive machine in which a cylinder head, on which an oil control valve unit designed to control oil pressure in a variable valve timing device of the drive machine is installed, is mounted to a crankcase, wherein an outer wall of the cylinder head is formed with an opening into which the oil control valve unit is partially inserted, and wherein a mating surface of the cylinder head and the crankcase is fastened by at least one pair of bolts spaced apart from each other by the opening. According to this embodiment, the cylinder head and the crankcase are fastened by the pair of bolts in such a way that the opening of the cylinder head is avoided.It is possible to ensure the mounting strength of the cylinder head and crankcase without interfering with the mounting of the oil control valve unit by the pair of bolts. Even if an opening is formed in the outer wall of the cylinder head, the strength of the cylinder head is not significantly reduced, and the mounting strength of the cylinder head and crankcase remains high, thus reducing vibration noise.

[0108] In the assembly structure described above, the cylinder head and crankcase are designed with a chain chamber for a timing chain, which transmits power to the variable valve timing control device. An outer wall of the cylinder head is designed with an opening such that the oil control valve unit passes through an inner side of the timing chain. According to this design, the oil control valve unit does not come into contact with the timing chain, and a dead space on the inner side of the timing chain can be used efficiently.

[0109] In the assembly structure described above, the outer surface of the chain chamber is divided in a transverse direction of the drive engine by the outer wall of the cylinder head and an outer wall of the crankcase, and a mating surface of the outer wall of the cylinder head and the outer wall of the crankcase is secured by a pair of bolts. According to this design, the strength in the vicinity of the opening in the outer wall of the cylinder head can be increased by increasing the fastening strength of the mating surface of the outer wall of the cylinder head and the outer wall of the crankcase.

[0110] In the assembly structure described above, the inner side of the chain chamber is divided by an inner wall of the cylinder head and an inner wall of the crankcase in a transverse direction of the drive engine, and the cam housing is installed on the inner wall of the cylinder head. According to this design, the cam housing can be installed on the inner wall of the cylinder head without being obstructed by the bolts.

[0111] In the assembly structure described above, the pair of bolts secures the mating surface of the cylinder head and the crankcase, with one axial direction of the bolts aligned with the cylinder's axial direction. According to this design, the drive engine vibration in the cylinder's axial direction can be efficiently avoided or dampened by the pair of bolts. Furthermore, since the axial direction of the bolts is aligned with the cylinder's axial direction, shear stress acting on the bolts due to the drive engine vibration can be avoided or dampened.

[0112] In the mounting structure of the drive unit described above, the cylinder head is provided with a suspension bracket that suspends a front surface of the drive unit from a vehicle body frame. According to this design, the fastening strength of the cylinder head's suspension bracket to the vehicle body frame can be increased by increasing the fastening strength of the cylinder head and the crankcase.

[0113] In the mounting structure of the drive machine described in the above embodiment, the oil control valve unit comprises an oil control valve, which controls the flow of oil, and a valve housing that carries the control valve. The outer circumferential surface of the valve housing is fitted with a sealing material that fills a space between the inner circumferential surfaces of the opening. According to this design, increasing the mounting strength of the cylinder head and the crankcase can prevent or dampen vibration of the cylinder head opening and improve the sealing performance of the opening and the valve housing.

[0114] The motorcycle described in the above embodiment includes the mounting structure of the drive unit. According to this design, the vibration noise of the vehicle's drive unit can be avoided by ensuring the secure fastening of the cylinder head and the crankcase.

Claims

[1] A mounting structure of a prime mover (41), in which a cylinder head (43) on which an oil control valve unit (61) configured to control an oil pressure in a variable valve timing device (110) of the prime mover (41) is installed is mounted on a crankcase (42), wherein an outer wall of the cylinder head (43) is formed with an opening (83) into which the oil control valve unit (61) is partially inserted, and wherein a mating surface (88) of the cylinder head (43) and the crankcase (42) is secured by at least one pair of bolts (87) spaced apart from each other across the opening (83). [2] The mounting structure of the drive machine (41) according to claim 1, wherein a chain chamber (84) for a timing chain (56) configured to transmit power to the variable valve timing device (110) is formed in the cylinder head (43) and the crankcase (42), and wherein the opening (83) in the outer wall of the cylinder head (43) is formed such that the oil control valve unit (61) passes through an inner side of the timing chain (56). [3] The mounting structure of the drive machine (41) according to claim 2, wherein an outer side of the chain chamber (84) is divided by the outer wall of the cylinder head (43) and an outer wall of the crankcase (42) in a transverse direction of the prime mover (41), and wherein the mating surface (88) of the outer wall of the cylinder head (43) and the outer wall of the crankcase (42) is fixed by the pair of bolts (87). [4] The mounting structure of the drive machine (41) according to claim 2 or 3, wherein an inner side of the chain chamber (84) is divided by an inner wall of the cylinder head (43) and an inner wall of the crankcase (42) in a transverse direction of the prime mover (41), and a cam housing (89) is installed on the inner wall of the cylinder head (43). [5] The mounting structure of the prime mover (41) according to any one of claims 1 to 4, wherein the pair of bolts (87) fixes the mating surface (88) of the cylinder head (43) and the crankcase (42) with an axial direction thereof aligned in a cylinder axial direction. [6] The mounting structure of the prime mover (41) according to any one of claims 1 to 5, wherein the cylinder head (43) is provided with a suspension bracket (59) which suspends a front surface of the prime mover (41) from a vehicle body frame (10). [7] The mounting structure of the drive machine (41) according to one of claims 1 to 6, wherein the oil control valve unit (61) comprises a control valve (62) configured to control a flow of the oil, and a valve housing (63) supporting the control valve (62), and wherein an outer peripheral surface of the valve housing (63) is mounted with a sealing material filling a space between inner peripheral surfaces of the opening (83). [8] A vehicle comprising the mounting structure according to any one of claims 1 to 7.

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