JP2006125258A - Ohc engine and saddle-riding type vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make an engine compact and enhance assembling performance without using a specific support member of a valve driving force transmission system, and to make the width of the engine in a crankshaft direction compact. <P>SOLUTION: This OHC engine is provided with a cylinder body 20 forming part of a cylinder of which one end has a combustion chamber; a crank case 19 forming part of a crank chamber positioned in the other end of the cylinder and jointed to the cylinder body 20; a crankshaft 24 rotatably supported by the crank case 19; a cam shaft of a valve system G positioned above the combustion chamber; and the valve driving force transmission system H transmitting rotation of the crankshaft 24 to the cam shaft. A jointed face of the cylinder body 20 and the crank case 19 supports at least part of the valve driving force transmission system H. A jointed face of the cylinder body 20 and a cylinder head 21 supports at least part of the valve driving force transmission system H. The jointed face of the cylinder body 20 and the cylinder head 21 and the jointed face of the cylinder body 20 and the crank case 19 support part of the valve driving force transmission system H, respectively. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an OHC engine and a straddle-type vehicle provided with a valve mechanism above a combustion chamber.

2. Description of the Related Art Some motorcycles and the like are equipped with an OHC engine that includes a valve mechanism above a combustion chamber and a valve driving force transmission mechanism that transmits rotation of a crankshaft to the valve mechanism. A valve-type driving force transmission mechanism using a cassette type gear train is known (for example, Patent Document 1).
Japanese Utility Model Publication No. 6-19811 (pages 1 to 4, FIGS. 1 to 4)

  This cassette type gear train has a high degree of freedom in design and is a cassette type, so it is easy to assemble, but it is necessary to provide a part to support the cassette type gear train on the side of the engine, and the direction of the crankshaft of the engine It was difficult to make the width compact. In particular, in a saddle riding type vehicle, the crankshaft is in the vehicle width direction.

  The present invention has been made in view of the above points, and is compact and easy to assemble without using a special valve driving force transmission mechanism support member, and the engine crankshaft direction width can be made compact. An object is to provide an OHC engine and a saddle-ride type vehicle.

  In order to solve the above-described problems and achieve the object, the present invention is configured as follows.

The invention according to claim 1 is a cylinder body forming a part of a cylinder having a combustion chamber at one end;
Forming a part of a crank chamber located at the other end of the cylinder, and a crankcase joined to the cylinder body;
A crankshaft rotatably supported by the crankcase;
A camshaft of a valve mechanism disposed above the combustion chamber;
An OHC engine comprising a valve driving force transmission mechanism for transmitting rotation of the crankshaft to the camshaft;
In the OHC engine, at least a part of the valve driving force transmission mechanism is supported by a joint surface between the cylinder body and the crankcase.

The invention according to claim 2 is a cylinder body forming a part of a cylinder having a combustion chamber at one end;
A cylinder head that forms part of the combustion chamber and is joined to the cylinder body; a crankshaft rotatably provided in a crank chamber formed at the other end of the cylinder;
A camshaft of a valve mechanism that is rotatably supported by the cylinder head above the combustion chamber;
An OHC engine comprising a valve driving force transmission mechanism for transmitting rotation of the crankshaft to the camshaft;
In the OHC engine, at least a part of the valve driving force transmission mechanism is supported by a joint surface between the cylinder body and the cylinder head.

The invention according to claim 3 is a cylinder body forming a part of a cylinder having a combustion chamber at one end;
A cylinder head that forms part of the combustion chamber and is joined to the cylinder body; a crankcase that forms part of a crank chamber located at the other end of the cylinder and is joined to the cylinder body;
A crankshaft rotatably supported by the crankcase;
A camshaft of a valve mechanism that is rotatably supported by the cylinder head above the combustion chamber;
An OHC engine comprising a valve driving force transmission mechanism for transmitting rotation of the crankshaft to the camshaft;
The OHC engine is characterized in that a part of the valve driving force transmission mechanism is supported by a joint surface between the cylinder body and the cylinder head and a joint surface between the cylinder body and the crankcase.

The invention according to claim 4 comprises two or more cylinders arranged in the crankshaft direction,
A rotation axis parallel to the crankshaft;
4. The OHC engine according to claim 1, wherein the valve driving force transmission mechanism includes a gear provided on the rotating shaft. 5.

  According to a fifth aspect of the present invention, a part of a supply path for lubricating oil supplied to the valve driving force transmission mechanism is formed on a joint surface between the cylinder body and the crankcase. The OHC engine according to claim 1 or claim 3.

  According to a sixth aspect of the present invention, a part of a supply path for lubricating oil supplied to the valve driving force transmission mechanism is formed on a joint surface between the cylinder body and the cylinder head. The OHC engine according to claim 2 or claim 3.

  According to a seventh aspect of the present invention, in any one of the first to third aspects, a bearing detent portion is provided on a support portion that supports at least a part of the valve driving force transmission mechanism. The OHC engine described in the item.

  The invention according to claim 8 is a saddle-ride type vehicle equipped with the OHC engine according to any one of claims 1 to 8.

  With the above configuration, the present invention has the following effects.

  According to the first aspect of the present invention, at least a part of the valve driving force transmission mechanism is supported by using the joint surface between the cylinder body and the crankcase, so that it is compact and easy to assemble. It is possible to make the direction width compact.

  According to the second aspect of the present invention, by supporting at least a part of the valve driving force transmission mechanism using the joint surface between the cylinder body and the cylinder head, it is compact and easy to assemble. It is possible to make the direction width compact.

  According to the third aspect of the present invention, a part of the valve driving force transmission mechanism is supported by using the joint surface between the cylinder body and the cylinder head and the joint surface between the cylinder body and the crankcase. Assemblability is good, and the crankshaft direction width of the engine can be made compact.

  According to a fourth aspect of the present invention, in addition to any one of the first to third aspects, the apparatus includes two or more cylinders arranged in the direction of the crankshaft, has a rotating shaft parallel to the crankshaft, and is driven by a valve drive. Since the force transmission mechanism includes a gear provided on the rotation shaft, the force transmission mechanism can be shortened in the crankshaft direction to make the engine compact.

  According to the fifth aspect of the present invention, in addition to the first or third aspect, a part of the supply path of the lubricating oil supplied to the valve driving force transmission mechanism is formed on the joint surface between the cylinder body and the crankcase. By forming, lubrication can be performed reliably, reliability can be improved, and a supply path can be easily formed from the joint surface.

  According to the sixth aspect of the present invention, in addition to the second or third aspect, a part of the supply path of the lubricating oil supplied to the valve driving force transmission mechanism is formed on the joint surface between the cylinder body and the cylinder head. By forming, lubrication can be performed reliably, reliability can be improved, and a supply path can be easily formed from the joint surface.

According to the invention of claim 7, in addition to any of claims 1 to 3,
By providing the bearing detent part in the support part that supports at least a part of the valve driving force transmission mechanism, the bearing can be deterred and lubrication can be performed reliably, and the reliability can be improved.

  According to the invention described in claim 8, the OHC engine according to any one of claims 1 to 8 is mounted, and it is compact without using a support member of a special valve driving force transmission mechanism. This is a straddle-type vehicle that is easy to assemble and that can make the crankshaft width of the engine compact.

  Embodiments of the OHC engine and the saddle riding type vehicle according to the present invention will be described below. The embodiment of the present invention shows the most preferable mode of the present invention, and the present invention is not limited to this. In this embodiment, a motorcycle is shown as a saddle-ride type vehicle, but the present invention can be similarly applied to an automatic tricycle or a buggy. Further, as a parallel multi-cylinder four-cycle engine, a four-cylinder four-cycle engine is shown, but the present invention can be similarly applied to a four-cycle engine such as a two-cylinder, three-cylinder, five-cylinder, or six-cylinder. 1 is a side view of a motorcycle, FIG. 2 is a cross-sectional view of a parallel multi-cylinder four-cycle engine, FIG. 3 is a cross-sectional view showing the arrangement of a crankshaft, a balancer shaft, and a main shaft, and FIG. 4 is an arrangement of a crankshaft and a balancer shaft FIG. 5 is a side view showing the valve drive force transmission mechanism, FIG. 6 is a side view showing the cam shaft portion of the valve drive mechanism, and FIG. 7 is a side view showing the arrangement of the crankshaft and the balancer shaft. 8 is a view of the camshaft of the valve mechanism as viewed from the camshaft direction.

  In the motorcycle according to this embodiment, as shown in FIG. 1, an engine 1 is mounted on a body frame 2 of the motorcycle. A front fork 10 is turnably provided on the front side of the body frame 2, and a front wheel 11 is supported on the front fork 10. A rear arm 12 is pivotally supported on the rear side of the body frame 2 by a link mechanism 4 and a rear cushion 5 so as to be swingable up and down, and a rear wheel 13 is supported on the rear arm 12.

  The engine 1 is a four-cycle engine including four cylinders 3a to 3d, and these cylinders 3a to 3d are arranged in series so as to be inclined forward and orthogonal to the traveling direction of the vehicle. . An exhaust pipe 6 is connected to the front side of each of the cylinders 3 a to 3 d, and the exhaust pipe 6 extends rearward of the vehicle body through the front side and the lower side of the engine 1. An intake pipe 7 is connected to the rear side of the cylinders 3a to 3d, and an air cleaner 8 is connected to the intake pipe 7. Each of the four cylinders 3 a to 3 d of the engine 1 is provided with a fuel injection device 9.

  Next, as shown in FIGS. 2 to 8, the engine 1 has a structure in which a cylinder body 20 and a cylinder head 21 are stacked on a crankcase 19 that is divided into upper and lower parts, and a head cover 50 is covered on the upper surface of the cylinder head 21. belongs to. An oil pan 52 is provided below the crankcase 19.

  As shown in FIGS. 2 and 3, each of the cylinders 3 a to 3 d includes a cylinder body 20 and a cylinder head 21 mounted on a crankcase 19 including an upper case 17 and a lower case 18. Pistons 22a to 22d are slidably fitted in the cylinder holes 3a1 to 3d1 of the cylinders 3a to 3d. Combustion chambers 80 a to 80 d are formed between the heads of the pistons 22 a to 22 d and the recesses 21 a to 21 d of the cylinder head 21.

  In each of the combustion chambers 80a to 80d, three intake valve openings 81b, 81a and 81b and two exhaust valve openings 82a and 82a are opened. The left, right, and center intake valve openings 81b, 81b, and 81a are led out to the rear wall of the cylinder head 21 by a trifurcated intake passage 81c, and the left, right exhaust valve openings 82a and 82a are bifurcated exhaust passages. 82b leads to the front wall of the cylinder head 21.

  The left and right intake valve openings 81b and the central intake valve opening 81a are provided with left and right intake valves 83 and a central intake valve 84, respectively, and the exhaust valve opening 82a is provided with an exhaust valve 85. The valves 83 to 85 extend upward so as to form a predetermined clamping angle, and are provided by valve springs 86c1 and 86c2 interposed between retainers 86a1 and 86a2 fixed to the upper ends of the valves 86b1 and 86b2. Energized in the closing direction. An intake lifter 87a1 is mounted on the upper part of each intake valve 83, 84, 83, and this intake lifter 87a1 is in contact with the cams 88a1, 88a1, 88a1 of the intake side camshaft 88a. An exhaust lifter 87b1 is mounted on the upper portion of each exhaust valve 85, 85, and this exhaust lifter 87b1 is in contact with the cams 88b1, 88b1 of the exhaust side camshaft 88b.

  In this embodiment, the engine 1 is an OHC engine, and the valve operating mechanism G has an intake side cam shaft 88a and an exhaust side cam shaft 88b. By the rotation of the intake side cam shaft 88a and the exhaust side cam shaft 88b, In this configuration, intake and exhaust are performed. The intake side camshaft 88a and the exhaust side camshaft 88b are disposed in parallel with the crankshaft 24 and are rotatably supported by the bearing portion of the cylinder head 21. In the valve mechanism G of this embodiment, the intake side camshaft 88a is disposed above the intake valves 83 and 84, and the cams 88a1, 88a1 and 88a1 are moved to the intake valves 83 and 84 by the rotation of the intake side camshaft 88a. , 83 are driven via the intake lifter 87a1. Similarly, the exhaust side camshaft 88b is disposed close to the exhaust valves 85 and 85, and the cams 88b1 and 88b1 drive the exhaust valves 85 and 85 via the exhaust lifter 87b1 by the rotation of the exhaust side camshaft 88b. The valve mechanism G may drive the intake valves 83, 84, 83 and the exhaust valves 85, 85 by a rocker arm or the like.

  Pistons 22a to 22d are slidably fitted in the cylinder holes 3a1 to 3d1 of the cylinders 3a to 3d. Each piston 22a-22d is connected to crankpins 25a-25d of the crankshaft 24 via connecting rods 23a-23d. The crank pins 25a to 25d are installed between a pair of crank webs 26a to 26d of the crankshaft 24 corresponding to the cylinders 3a to 3d. The crankshaft 24 is rotatably supported by five bearing support portions 19a1 to 19e1 of the crankcase 19 via bearings 27a to 27e, respectively.

  A balancer shaft 32 is disposed in the crankcase 19 in parallel with the crankshaft 24. The balancer shaft 32 is rotatably supported by four bearing support portions 19a to 19d of the crankcase 19 via respective bearings 28a to 28d. The bearings 28 a to 28 d of the balancer shaft 32 are arranged corresponding to the bearings 27 a to 27 d of the crankshaft 24, and can share the four bearing support portions 19 a to 19 d of the crankcase 19.

  A driven gear 33 provided at the center portion of the balancer shaft 32 meshes with a drive gear 34 provided at the center portion of the crankshaft 24. The driven gear 33 and the drive gear 34 have the same diameter, and the crankshaft 24 and the balancer shaft 32 rotate in opposite directions at the same rotational speed. Balance weights 35 and 36 are provided on both sides of the driven gear 33 at portions from both ends of the balancer shaft 32.

  Further, in this embodiment, as shown in FIGS. 3 and 4, a power input portion C is provided in the middle portion between the balance weights 35 and 36 of the balancer shaft 32 to extract and input power from the crankshaft 24. The power input portion C is composed of a driven gear 33 that meshes with the drive gear 34. The drive gear 34 is formed integrally with the crank web 26b, and the driven gear 33 is provided by being press-fitted into the balancer shaft 32, so that power can be taken out without lengthening the balancer shaft 32 and the crankshaft 24. The bearing 28b of the balancer shaft 32 is disposed between the balance weight 35 and the power input portion C, and the bearing 28c is disposed between the balance weight 36 and the power input portion C, so that the balancer shaft 32 can be reliably supported. . Further, the bearings 28b and 28c of the balancer shaft 32 are arranged on both sides of the power input portion C, so that the balancer shaft 32 can be reliably supported.

  As shown in FIGS. 2 and 8, the balancer shaft 32 has one balance weight 35 of the balancer shaft 32 disposed between the crank webs 26a and 26a on both sides of the crank pin 25a of the cylinder 3a. The other balance weight 36 of the balancer shaft 32 is arranged corresponding to the crank webs 26c, 26c on both sides of the crank pin 25c of the cylinder 3d, and the radial front ends of the balance weights 35, 36 are the crank webs 26a, 26a and 26c. The crank webs 26c and 26c are configured to pass through the inner portion of the outer periphery of the crank webs 26c and 26c and rotate. As described above, the balancer shaft 32 is configured such that the rotation locus LO1 of the balance weights 35 and 36 provided on the balancer shaft 32 and the rotation locus LO2 of the crank webs 26a and 26a and the crank webs 26c and 26c overlap in the crankshaft direction view. Thus, the distance between the balancer shaft 32 and the crankshaft 24 can be shortened, and the entire engine can be made compact.

  In this embodiment, as shown in FIGS. 2 and 3, a valve driving force transmission mechanism H that transmits power from the balancer shaft 32 to the valve operating mechanism G is provided. The intake side cam shaft 88a and the exhaust side cam shaft 88b of the valve mechanism G are rotated in conjunction with the shaft 32 to perform intake and exhaust at a predetermined timing.

  The power input side H1 of the valve drive force transmission mechanism H is constituted by a cam drive gear 70 disposed between the balance weights 35 and 36 on the balancer shaft 32. The cam drive gear 70 is smaller in diameter than the driven gear 33 and has a speed reduction mechanism J that decelerates on the balancer shaft 32. The speed reduction mechanism J includes a cam drive gear 70 having a smaller diameter than the driven gear 33. The power output side H2 of the valve drive force transmission mechanism H includes an intake side driven gear 71 and an exhaust gas disposed on a cam shaft constituted by the intake side cam shaft 88a and the exhaust side cam shaft 88b of the valve mechanism G. A side driven gear 72 is used. The intake side driven gear 71 and the exhaust side driven gear 72 mesh with each other and rotate in conjunction with each other.

  This valve driving force transmission mechanism H has an intermediate gear group H3 between the power input side H1 and the power output side H2. The intermediate gear group H3 includes a first gear 73, a second gear 74, a third gear 75, and a fourth gear 76, which rotate in mesh with each other. The first gear 73 is formed on the rotary shaft 90, and the rotary shaft 90 is pivotally supported by a bearing 91a. The second gear 74 and the third gear 75 are formed on a rotating shaft 92, and the rotating shaft 92 is pivotally supported by a bearing 93a. The fourth gear 76 is rotatably supported by the gear case 94. The first gear 73 meshes with the cam drive gear 70, the fourth gear 76 meshes with the intake side driven gear 71, and the power of the balancer shaft 32 is transmitted from the cam drive gear 70 to the first gear 73, the second gear 74, and the third gear. It is transmitted to the gear 75 and the fourth gear 76 and further transmitted to the intake side driven gear 71 and the exhaust side driven gear 72 of the valve mechanism G to rotate the intake side cam shaft 88a and the exhaust side cam shaft 88b. In this embodiment, the valve driving force transmission mechanism H is configured by a gear group, but may be configured by a chain, a belt, or the like.

  In this way, the valve driving force transmission mechanism H that transmits power from the balancer shaft 32 to the valve mechanism G is provided, and power is not taken out from the crankshaft 24 to the valve mechanism G, thereby achieving stable valve operation. An engine having a very good driving feeling can be made compact while ensuring driving of the driving force transmission mechanism H.

  Further, since the power input side H1 of the valve drive force transmission mechanism H is disposed between the balance weights 35 and 36 on the balancer shaft 32, the kinks of the balancer shaft 32 can be reduced, rotation fluctuation is small, and more stable. The driven valve drive force transmission mechanism H can be secured.

  Further, a power input portion C for inputting power from the crankshaft 24 is provided on the balancer shaft 32, and the cam drive gear 70 on the power input side H1 of the valve driving force transmission mechanism H is provided in the vicinity of the power input portion C. With this arrangement, it is possible to reduce the kinking of the balancer shaft 32, to reduce the rotational fluctuation, and to ensure more stable driving of the valve drive force transmission mechanism H. Further, since the power input portion C is disposed between the plurality of balance weights 35 and 36, the kinking of the balancer shaft 32 can be reduced, rotation fluctuation is small, and the valve driving force transmission mechanism H can be driven more stably. Can be secured. Further, the power input unit C can input the power extracted from the center of the crankshaft 24, thereby reducing the kinking of the crankshaft 24 and reducing the rotational fluctuation.

  Further, as shown in FIG. 2, the valve driving force transmission mechanism H is arranged outside the cylinder holes 3a1 to 3d1 as viewed in the cylinder axial direction, so that the interval between the cylinder holes 3a1 to 3d1 as shown in FIG. W1 can be packed and the engine can be made compact by shortening in the direction of the crankshaft.

  Further, as shown in FIG. 6, the power output side H2 of the valve drive force transmission mechanism H has a flange portion 88a2 formed on the intake side cam shaft 88a, and the intake side driven gear 71 is connected to the flange portion 88a2 by a bolt 88a3. Tightened and fixed. A flange portion 88b2 is formed on the exhaust-side cam shaft 88b, and the exhaust-side driven gear 72 is fastened and fixed to the flange portion 88b2 by a bolt 88b3. Thus, by arranging the intake side driven gear 71 and the exhaust side driven gear 72 on the cam shaft of the valve mechanism G without using any special member, the engine can be made compact by shortening in the cam shaft direction.

  In this embodiment, balance weights 35 and 36 are provided on the balancer shaft 32 asymmetrically with respect to the center of the balancer shaft 32. In the case of a balancer that eliminates the couple due to primary inertia, it can be arranged asymmetrically with respect to the center of the crank. Therefore, even if the position of the valve drive force transmission mechanism H is freely arranged, the balancer function is not impaired. Absent.

  The crank webs of the cylinders 3a to 3d each have a pair of crank webs 26a to 26d. The ratio of the reciprocating mass and the rotational mass of the pair of crank webs 26a of the first cylinder 3a is different from each other, and the second cylinder 3b. Although the ratio of the reciprocating mass and the rotating mass of the pair of crank webs 26b is different from each other, the ratio of the reciprocating mass and the rotating mass of the first cylinder 3a and the second cylinder 3b is formed to be equal to each other. Even if H is provided, the engine can be made compact without reducing the balancer function.

  In this way, the valve driving force transmission mechanism H that transmits power from the balancer shaft 32 to the valve mechanism G is provided, and power is not taken out from the crankshaft 24 to the valve mechanism G, thereby achieving stable valve operation. An engine having a very good driving feeling can be made compact while ensuring driving of the driving force transmission mechanism H.

  Further, in this embodiment, as shown in FIGS. 3 and 4, the length L1 of the balancer shaft 32 is made smaller than the interval L2 between the crank webs 26a, 26d on both ends on the crankshaft 24, and one side in the crankshaft direction is set. The space K can be secured next to the balancer shaft 32 adjacent to the crankshaft 24 by the arrangement of the balancer shaft 32. A balance weight 35 at one end of the balancer shaft 32 is provided at a position corresponding to the crank web 26a of the cylinder 3a at one end, and a balance weight 36 at the other end is provided at the crank web 26c of the cylinder 3c adjacent to the cylinder 3d at the other end. The space K can be secured next to the balancer shaft 32 corresponding to the other end cylinder 3d. A power transmission part D is provided at the end of the balancer shaft 32 on the side 32a opposite to the side 32a that is displaced. The power transmission portion D is constituted by an output gear 38 formed integrally with the end portion of the balancer shaft 32.

  The crankcase 19 is provided with a shift mechanism 43 and a clutch mechanism 44, and the configuration of the shift mechanism 43 and the clutch mechanism 44 will be described with reference to FIG. The output gear 38 of the balancer shaft 32 is connected to the main shaft 41 via a multi-plate clutch mechanism 44. A multi-stage transmission gear 49 is mounted on the main shaft 41, and each transmission gear 49 is meshed with a transmission gear 420 mounted on the drive shaft 42 correspondingly. Either one or both of the transmission gear 49 and the transmission gear 420 are attached to the main shaft 41 or the drive shaft 42 in an idle state, except for the selected transmission gear. Therefore, rotation transmission from the main shaft 41 to the drive shaft 42 is performed only through the selected pair of transmission gears. It is transmitted from the drive shaft 42 to the rear wheel 13 via the rear wheel drive chain 13a.

  The shift operation for selecting the transmission gear 49 and the transmission gear 420 to change the transmission gear ratio is performed by a shift cam 421 that is a shift input shaft. The shift cam 421 has a plurality of cam grooves 421a, and a shift fork 422 is attached to each cam groove 421a. Each shift fork 422 is engaged with a predetermined transmission gear 49 and transmission gear 420 of the main shaft 41 and the drive shaft 42, respectively. Due to the rotation of the shift cam 421, the shift fork 422 moves in each axial direction according to the cam groove 421a, and only the pair of the transmission gear 49 and the transmission gear 420 at positions corresponding to the rotation angle of the shift cam 421 are the main shaft 41 and the drive shaft 42. On the other hand, both of them are fixed by the spline so that the rotation is transmitted and the transmission gear position is determined.

  The shift mechanism 43 rotates the shift cam 421 by a predetermined angle via the shift link mechanism 425 by driving the shift actuator 61. As a result, the shift fork 422 moves in the axial direction by a predetermined amount according to the cam groove 421a, and the pair of transmission gears 49 and the transmission gear 420 are sequentially fixed to the main shaft 41 and the drive shaft 42 to transmit the rotations of the respective reduction ratios. .

  The clutch mechanism 44 of this embodiment is, for example, a multi-plate friction clutch, and is rotatably provided with respect to the balancer shaft 32 that meshes with an output gear 38 that is integrally formed with the balancer shaft 32. An outer driver 443 that transmits torque from the balancer shaft 32 by being provided integrally with the gear 441, a plurality of friction disks 445 that are friction plates provided integrally with the outer driver 443, and an inner driver 447, which is a friction plate integrally provided on 447, and an inner member to which torque is transmitted from the outer driver 443 by frictional force generated between the plurality of friction disks 445 and the plurality of clutch plates 449. And a driver 447.

  The gear 441 is rotatably provided on the main shaft 41 on one end side of the main shaft 41, and the outer driver 443 is integrally provided on the boss portion of the gear 441, thereby rotating the rotation shaft of the main shaft 41. It is rotatable with respect to the main shaft 41 while being restricted from moving in the direction. The inner driver 447 is integrally provided on the main shaft 41 on one end portion side of the main shaft 41 (further end portion side than the gear 441).

  The inner driver 447 is provided inside the cylindrical outer driver 443, and the rotation centers of the gear 441, the outer driver 443, the inner driver 447, and the main shaft 41 are coincident and exist concentrically.

  An engagement portion having an engagement hole 443A engaged with a circular engagement protrusion 441A provided on a boss portion of the gear 441 on one end side of the opening of the cylindrical outer driver 443. 443B is provided, and the outer driver 443 is centered and fixed to the gear 441 using the engaging portion 443B and the engaging hole 443A. Each friction disk 445 is a ring-shaped thin plate, and the outer peripheral edge of each friction disk 445 is a cylinder so that the plane of each friction disk 445 is substantially perpendicular to the direction of the rotation axis of the main shaft 41. Is supported on the inner periphery of the cylindrical portion of the outer driver 443. With this support, each friction disk 445 is slightly movable relative to the outer driver 443 in the direction of the rotation axis of the main shaft 41, and the main shaft 41 with respect to the outer driver 443. It is restricted so that it cannot rotate relatively in the rotation direction.

  Further, a predetermined interval (a distance slightly larger than the thickness of the clutch plate 449) is provided between the planes of the friction disks 445.

  The inner driver 447 has a cylindrical shape, and is provided with a circular flange portion 447A having an outer diameter substantially equal to the outer diameter of the clutch plate 449 on one end side of the opening, and on the outer periphery of the cylindrical portion, A plurality of clutch plates 449 are supported. With this support, each clutch plate 449 is slightly movable relative to the inner driver 447 in the direction of the rotation axis of the main shaft 41, and the main shaft 41 with respect to the inner driver 447. It is restricted so that it cannot rotate relatively in the rotation direction.

  Further, the inner driver 447 is fixed to one end portion side of the main shaft 41 so that the flange portion 447A is on the engagement portion 443B side of the outer driver 443.

  Each clutch plate 449 is a ring-shaped thin plate, and the inner peripheral edge of each clutch plate 449 is a cylinder so that the plane of the plate of each clutch plate 449 is substantially perpendicular to the direction of the rotation axis of the main shaft 41. The inner driver 447 is supported on the outer periphery of the cylindrical portion.

  In addition, a predetermined distance (a distance slightly larger than the thickness of the friction disk 445) is provided between the planes of the clutch plates 449.

  The outer diameter of each clutch plate 449 is slightly smaller than the inner diameter of the cylindrical portion of the cylindrical outer driver 443, and the inner diameter of each friction disk 445 is smaller than the outer diameter of the cylindrical portion of the cylindrical inner driver 447. Slightly larger. The friction disks 445 and the clutch plates 449 are alternately arranged in the rotation axis direction of the main shaft 41. Between the friction disks 445 and the clutch plates 449, the rotation axis direction of the main shaft 41 is provided. There are slight gaps.

  Outer of each of the friction disks 445 and each of the clutch plates 449 arranged alternately and outside of the main shaft 41 in the rotation axis direction, on the side of the engaging portion 443B of the outer driver 443, the inner driver There is a pressing portion 447B configured by a flange portion 447A of 447. The pressing portion 447B sandwiches each friction disk 445 and each clutch plate 449 together with the pressure plate 451 in the rotation axis direction of the main shaft 41, and friction between each friction disk 445 and each clutch plate 449. It generates power.

  The pressure plate 451 is provided so as to be movable relative to the inner driver 447 in the direction of the rotation axis of the main shaft 41, and is configured to rotate simultaneously with the inner driver 447. The pressure plate 451 has a flat pressing portion 451B, and the pressing portion 451B is substantially parallel to the planes of the friction disks 445 and the clutch plates 449.

  The inner driver 447 has a plurality of cylindrical guide portions 447C for guiding the pressure plate 451, and a plurality of compression springs 450 are provided so as to surround each of the guide portions 447C. The spring 450 biases the pressure plate 451 in a direction in which the pressing portion 451B of the pressure plate 451 approaches the pressing portion 447B of the inner driver 447.

  Further, in a state where the clutch mechanism 44 is engaged and connected, the compression spring 450 moves the pressure plate 451 in the direction of the flange portion 447A of the inner driver 447 and is urged, and the pressure portion 447B of the inner driver 447 and the pressure. Each friction disk 445 and each clutch plate 449 are sandwiched and pressed by the pressing portion 451B of the plate 451, and a frictional force is generated between each friction disk 445 and each clutch plate 449. Torque can be transmitted to the inner driver 447.

  On the other hand, in a state where the clutch mechanism 44 is not engaged (a state in which the clutch mechanism 44 is not connected and torque is not transmitted), the pressure plate 451 is moved by a push rod 455 described later, and the pressing portion 451B of the pressure plate 451 is moved. It is separated from the friction disk 445 located closest to the pressing portion 451B of the pressure plate 451.

  Therefore, each friction disk 445 and each clutch plate 449 are not sandwiched, and there is a slight gap in the direction of the rotation axis of the main shaft 41 between each of these friction disks 445 and each clutch disk 449. A frictional force capable of transmitting torque is not generated between the plate 449 and the plate 449. Note that the pressure plate 451 is moved and controlled by the clutch actuator 60.

  The pressure plate 451 is moved in the direction of the rotation axis of the main shaft 41 by the clutch actuator 60 and the compression spring 450, and the clutch is engaged and engaged (becomes a state where power can be transmitted) according to this movement, or is not connected. It becomes a state (a state where power cannot be transmitted).

  The push rod 455 is attached to the compression spring 450 in the direction of the rotation axis of the main shaft 41 which is the left direction in FIG. 3 and the pressing portion 451B of the pressure plate 451 is separated from the pressing portion 447B of the inner driver 447. When moving with a force larger than the force, the pressure plate 451 is pushed by the push rod 455 and moves in the same manner.

  Conversely, when the push rod 455 moves to the left in FIG. 3, the pressure plate 451 moves in the same manner by pushing the push rod 455 with the urging force of the compression spring 450. A spherical ball 459 is provided inside the cylindrical main shaft 41 adjacent to the other end of the push rod 455, and a push rod 461 is provided adjacent to the ball 459. .

  The operation rod 461A1 is in contact with one end 461A of the push rod 461, and the operation rod 461A1 protrudes from the other end of the cylindrical main shaft 41. The operating rod 461A1 that protrudes from the push rod 461 is integrally provided with a piston 463 that constitutes the clutch actuator 60. The piston 463 is guided by the cylinder body 465 in the direction of the rotation axis of the main shaft 41. It is slidable.

  When hydraulic oil, which is an example of a compressed fluid, is supplied to a space 467 surrounded by the piston 463 and the cylinder body 465, the piston 463 is pushed to the right in FIG. 2 to move, and the operation rod 461A1, push The pressure plate 451 is pushed rightward in FIG. 3 via the rod 461, the ball 459, and the push rod 455. As described above, when the pressure plate 451 is pushed rightward in FIG. 3 and the pressing portion 451B of the pressure plate 451 is separated from the friction disk 445, the clutch is disconnected.

  Next, the case where the clutch mechanism 44 is changed from the non-connected state to the connected engagement state will be described. In a state where the clutch mechanism 44 is not connected, the piston 463 of the clutch actuator 60 pushes the pressure plate 451 rightward in FIG. 2 via the operation rod 461A1, the push rod 461, the ball 459, and the push rod 455. The pressing portion 451B of the pressure plate 451 is kept away from the friction disk 445. Even in this state, the pressure plate 451 is urged to the left in FIG. 3 by the compression spring 450, so that the piston 463 passes through the push rod 455, the ball 459, the push rod 461, and the operation rod 461A1. Thus, it is biased to the left in FIG.

  The piston 463 urged by the pressure plate 451 and the compression spring 450 gradually moves in the left direction in FIG. 3 due to the movement of the hydraulic oil from the state where the clutch mechanism 44 is not connected. Along with this, the pressure plate 451 gradually moves to the left in FIG. 3, and eventually the clutch mechanism 44 starts connection engagement (starts transmission of power), and the pressure plate 451 further moves to the left in FIG. As a result, the frictional force generated between the friction disk 445 and the clutch plate 449 increases due to the urging force of the compression spring 450, so that there is almost no slip between the friction disk 445 and the clutch plate 449, and the clutch engagement is achieved. Complete.

  Next, a support structure and a lubrication structure of the valve drive force transmission mechanism will be described with reference to FIGS. 9 is an exploded side view of the crankcase, FIG. 10 is a top view of the disassembled lower case, FIG. 11 is a top view of the disassembled upper case, FIG. 12 is a bottom view of the disassembled upper case, and FIG. FIG. 14 is a side view of the bearing cap, FIG. 15 is a cross-sectional view of the oil pump portion of the oil pan, FIG. 16 is a cross-sectional view of the lubricating oil supply passage from the oil pan to the bearing portion, 17 is a cross-sectional view taken along line XVII-XVII in FIG. 16, FIG. 18 is a side view of the cylinder body, FIG. 19 is a top view of the cylinder body, FIG. 20 is a cross-sectional view taken along line XX-XX in FIG. Is a sectional view taken along line XXI-XXI in FIG. 19, FIG. 22 is a sectional view taken along line XXII-XXII in FIG. 19, and FIG. 23 is a side view of the bearing cap.

  As shown in FIGS. 2, 3, and 5, the engine 1 includes a cylinder body 20 that forms a part of a cylinder having combustion chambers 80a to 80d at one end, and a part of the combustion chambers 80a to 80d. The cylinder head 21 to be joined to the cylinder body 20, the crank chambers 80a1 to 80d1 located at the other end of the cylinder are partly formed, the crank case 19 to be joined to the cylinder body 20, and the crank case 19 to be rotatably supported The crankshaft 24, the intake side camshaft 88a of the valve mechanism G that is rotatably supported by the cylinder head 21 above the combustion chambers 80a to 80d, and the camshaft that is the exhaust side camshaft 88b. Is provided with a valve drive force transmission mechanism H that transmits the rotation of the motor to the camshaft via the balancer shaft 32. In this embodiment, the rotation of the crankshaft 24 is transmitted to the camshaft via the balancer shaft 32, but without using the balancer shaft 32, the crankshaft 24 is directly transmitted via the valve drive force transmission mechanism H. It may be transmitted to the camshaft.

  A support structure for the valve drive force transmission mechanism by the joint surface of the cylinder body 20 and the crankcase 19 will be described with reference to FIGS. The crankcase 19 includes an upper case 17 and a lower case 18, and the upper case 17 has a lower joint surface 17a and an upper joint surface 17b, and the lower case 18 has an upper joint surface 18a. The lower joint surface 17a of the upper case 17 and the upper joint surface 18a of the lower case 18 are joined and fastened and fixed by the fastening bolt 100 and the nut 101. The crankshaft 24 is rotatably supported by five bearing support portions 19a1 to 19e1 formed in the upper case 17 and the lower case 18 via bearings 27a to 27e, respectively. The balancer shaft 32 is rotatably supported by four bearing support portions 19a to 19d formed in the upper case 17 and the lower case 18 via respective bearings 28a to 28d.

  The lower joint surface 20a of the cylinder body 20 shown in FIGS. 18 to 23 is joined to the upper joint surface 17b of the upper case 17 of the crankcase 19, and is fastened and fixed by the tightening bolts 110 and the nuts 111. As shown in FIGS. 12 to 14, a support portion 17c is formed on the upper joint surface 17b of the upper case 17 so as to extend in the center of the upper case 17 and to the side. The bearing 91a of the rotary shaft 90 is applied to the support portion 17c, and the bearing caps 112a and 112b shown in FIG. 13 are fastened and fixed by the mounting bolts 113 so that the rotary shaft 90 is pivotally supported by the bearing 91a. .

  The support portion 17c is provided with a bearing detent portion 17c1. The bearing detent portion 17c1 is formed in a hole shape. A locking pin 91a1 is formed on the bearing 91a. By engaging the locking pin 91a1 with the bearing detent portion 17c1 and assembling the bearing 91a to the support portion 17c, the bearing 91a is detented to ensure lubrication. Can be performed and reliability can be improved.

  A support structure for the valve drive force transmission mechanism by the joint surface between the cylinder body 20 and the cylinder head 21 will be described with reference to FIGS. The cylinder body 20 has a lower joint surface 20a and an upper joint surface 20b. The cylinder body 20 is fastened and fixed to the upper joint surface 20b of the cylinder body 20 by being joined to the lower joint surface 21a of the cylinder head 21.

  A support portion 20c is formed on the upper joint surface 20b of the cylinder body 20 so as to extend in the center and to the side. The bearing 93a of the rotary shaft 92 is applied to the support portion 20c, and the bearing caps 122a and 122b shown in FIG. 23 are fastened and fixed by the mounting bolts 123 so that the rotary shaft 92 is pivotally supported by the bearing 93a. .

  The support portion 20c is provided with a bearing detent portion 20c1. The bearing detent portion 20c1 is formed in a hole shape. A locking pin 93a1 is formed on the bearing 93a. By engaging the locking pin 93a1 with the bearing detent portion 20c1 and assembling the bearing 93a to the support portion 20c, the bearing 93a is detented to ensure lubrication. Can be performed and reliability can be improved.

  As described above, by using the joint surface between the cylinder body 20 and the cylinder head 21 and the joint surface between the cylinder body 20 and the crankcase 19 to support each part of the valve drive force transmission mechanism H, the compact and assemblability is achieved. The crankshaft direction width of the engine 1 can be made compact. Note that only the joint surface between the cylinder body 20 and the crankcase 19 may be used to support at least a part of the valve driving force transmission mechanism H, or only the joint surface between the cylinder body 20 and the cylinder head 21 may be used. Thus, at least a part of the valve driving force transmission mechanism H may be supported. In this way, it can be supported using the joint surface between the cylinder body 20 and the cylinder head 21 and the joint surface between the cylinder body 20 and the crankcase 19 without using a special support member for the valve drive force transmission mechanism H, and is compact. This is a straddle-type vehicle that is easy to assemble and that can make the crankshaft direction width of the engine 1 compact.

  Next, the lubricating oil supply path of the OHC engine will be described with reference to FIGS. An oil pan 52 is provided below the lower case 18 of the crankcase 19. The oil pan 52 stores lubricating oil for lubricating each lubricating portion of the engine 1, an oil strainer 53 is disposed inside, and an oil filter 54 is provided on the side portion.

  Further, as shown in FIG. 16, a lubricating oil return passage 52 a is formed in the side wall of the oil pan 52, and the lubricating oil falling through the return passage 18 m of the lower case 18 flows through the return passage 52 a of the oil pan 52. And returned to the inside of the oil pan 52. The lower case 18 is provided with an oil pump 120. The oil pump 120 rotates in conjunction with the crankshaft 24 by an interlocking mechanism (not shown), sucks the lubricating oil in the oil pan 52 through the oil strainer 53, It is supplied to a supply passage 18 c formed in the case 18. The lubricating oil flows from the supply passage 18c through the supply passage 52b formed on the side wall of the oil pan 52, passes through the oil filter 54, and further flows through the supply passage 52c to the supply passage 18c of the lower case 18.

  As shown in FIGS. 16 and 17, the supply passage 18c of the lower case 18 communicates with the supply passage 17e of the upper case 17, and the supply passage 17e communicates with a main gallery 17f formed in the crankshaft direction. . The branch supply passages 17f1 to 17f5 branch from the main gallery 17f, and lubricating oil flows through the branch supply passages 17f1 to 17f5 and is supplied to the bearings 27a to 27e of the bearing support portions 19a1 to 19e1 to be lubricated. Further, branch supply passages 17f21 and 17f22 are communicated with the branch supply passage 17f2, and lubricating oil flows through the branch supply passages 17f21 and 17f22 and is supplied to the crank pins 25a and 25b for lubrication. Branch supply passages 17f41 and 17f42 communicate with the branch supply passage 17f4, and lubricating oil flows through the branch supply passages 17f41 and 17f42 to be supplied to the crank pins 25c and 25d for lubrication.

  As shown in FIGS. 9 and 11, the main gallery 17 communicates with the sub gallery 17k via the transfer passage 17g. Branch passages 17k1 to 17k5 are formed from the sub gallery 17k, and the branch passages 17k1 to 17k5 open to the upper joint surface 17b of the upper case 17.

  As shown in FIG. 12, a supply passage 17 n communicates with the supply passage 17 e of the upper case 17, and the supply passage 17 n communicates with the supply passage 20 n of the cylinder body 20. Further, the branch passages 17k1 to 17k3 of the upper case 17 communicate with the supply passages 20k1 to 20k3 of the cylinder body 20. The supply passage 20n and the supply passages 20k1 to 20k3 of the cylinder body 20 are opened to the lower joint surface 20a and the upper joint surface 20b of the cylinder body 20.

  The supply passage 20k1 communicates with the supply passage 21k1 of the cylinder head 21 and supplies lubricating oil to the cylinder head 21 side. The supply passages 20k2 and 20k3 supply lubricating oil to the bearing 93a for lubrication.

  In this way, a part of the supply path of the lubricating oil supplied to the valve driving force transmission mechanism H is formed on the joint surface between the cylinder body 20 and the crankcase 19, and lubrication can be reliably performed. Reliability can also be improved, and a supply path can be easily formed from the joint surface. In addition, a part of the supply path of the lubricating oil supplied to the valve drive force transmission mechanism H is formed on the joint surface between the cylinder body 20 and the cylinder head 21, so that the lubrication can be performed reliably and reliability. In addition, the supply path can be easily formed from the joint surface.

  The present invention uses the joint surface between the cylinder body and the crankcase to support at least a part of the valve driving force transmission mechanism, thereby making it compact and easy to assemble and making the crankshaft width in the engine compact. Is possible.

1 is a side view of a motorcycle. It is sectional drawing of a parallel multicylinder 4 cycle engine. It is sectional drawing which shows arrangement | positioning of a crankshaft, a balancer shaft, and a main shaft. It is sectional drawing which shows arrangement | positioning of a crankshaft and a balancer shaft. It is a side view which shows a valve drive force transmission mechanism. It is a side view which shows the cam shaft part of a valve mechanism. It is a side view which shows arrangement | positioning of a crankshaft and a balancer shaft. It is the figure which looked at the cam shaft of the valve operating mechanism from the cam shaft direction. It is the side view which disassembled the crankcase. It is a top view of the decomposed lower case. It is a top view of the disassembled upper case. It is a bottom view of the disassembled upper case. It is sectional drawing which follows the XIII-XIII line | wire of FIG. It is a side view of a bearing cap. It is sectional drawing of the oil pump part of an oil pan. It is sectional drawing of the supply path of the lubricating oil from an oil pan to a bearing part. It is sectional drawing which follows the XVII-XVII line of FIG. It is a side view of a cylinder body. It is a top view of a cylinder body. It is sectional drawing which follows the XX-XX line of FIG. It is sectional drawing which follows the XXI-XXI line | wire of FIG. It is sectional drawing which follows the XXII-XXII line | wire of FIG. It is a side view of a bearing cap.

Explanation of symbols

1 Engine 3a-3d Cylinder 3
DESCRIPTION OF SYMBOLS 19 Crankcase 19a-19d Four bearing support parts of the crankcase 19 20 Cylinder body 21 Cylinder head 24 Crankshaft 27a-27e Crankshaft 24 bearing 28a-28d The balancer shaft 32 bearing 28a-28d
32 Balancer shaft 35, 36 Balance weight G Valve mechanism H Valve drive force transmission mechanism

Claims (8)

A cylinder body forming part of a cylinder having a combustion chamber at one end;
Forming a part of a crank chamber located at the other end of the cylinder, and a crankcase joined to the cylinder body;
A crankshaft rotatably supported by the crankcase;
A camshaft of a valve mechanism disposed above the combustion chamber;
An OHC engine comprising a valve driving force transmission mechanism for transmitting rotation of the crankshaft to the camshaft;
An OHC engine characterized in that at least a part of the valve driving force transmission mechanism is supported by a joint surface between the cylinder body and the crankcase. A cylinder body forming part of a cylinder having a combustion chamber at one end;
A cylinder head that forms part of the combustion chamber and is joined to the cylinder body; a crankshaft rotatably provided in a crank chamber formed at the other end of the cylinder;
A camshaft of a valve mechanism that is rotatably supported by the cylinder head above the combustion chamber;
An OHC engine comprising a valve driving force transmission mechanism for transmitting rotation of the crankshaft to the camshaft;
An OHC engine characterized in that at least a part of the valve driving force transmission mechanism is supported by a joint surface between the cylinder body and the cylinder head. A cylinder body forming part of a cylinder having a combustion chamber at one end;
A cylinder head that forms part of the combustion chamber and is joined to the cylinder body; a crankcase that forms part of a crank chamber located at the other end of the cylinder and is joined to the cylinder body;
A crankshaft rotatably supported by the crankcase;
A camshaft of a valve mechanism that is rotatably supported by the cylinder head above the combustion chamber;
An OHC engine comprising a valve driving force transmission mechanism for transmitting rotation of the crankshaft to the camshaft;
An OHC engine, wherein a part of the valve driving force transmission mechanism is supported by a joint surface between the cylinder body and the cylinder head and a joint surface between the cylinder body and the crankcase. With two or more cylinders lined up in the crankshaft direction,
A rotation axis parallel to the crankshaft;
The OHC engine according to any one of claims 1 to 3, wherein the valve driving force transmission mechanism includes a gear provided on the rotation shaft.   4. The OHC according to claim 1, wherein a part of a supply path of lubricating oil supplied to the valve driving force transmission mechanism is formed on a joint surface between the cylinder body and the crankcase. 5. engine.   4. The OHC according to claim 2, wherein a part of a supply path for lubricating oil supplied to the valve driving force transmission mechanism is formed on a joint surface between the cylinder body and the cylinder head. 5. engine.   The OHC engine according to any one of claims 1 to 3, wherein a bearing detent portion is provided in a support portion that supports at least a part of the valve driving force transmission mechanism.   A straddle-type vehicle equipped with the OHC engine according to any one of claims 1 to 8.

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