JP6118057B2 - Rocker shaft arrangement structure of 4-stroke internal combustion engine - Google Patents

Description

  The present invention relates to a rocker shaft arrangement structure for a four-stroke internal combustion engine.

In a valve operating device for a four-stroke internal combustion engine with a rocker arm in which intake and exhaust valves are arranged substantially in parallel to reduce the size of the internal combustion engine and increase the speed during operation, the rocker shafts of the intake valve and the exhaust valve Are made close to each other along a plane parallel to the mating surfaces of the cylinder block and the cylinder head (see Patent Document 1 ).

  In the one described in Patent Document 1, when the rocker shafts are arranged close to each other along a plane parallel to and near the mating surface of the cylinder block and the cylinder head, both the rocker shafts located outside the rocker shafts are arranged. Since the rocker shafts are arranged side by side in the space between the camshaft bearing portions, it is difficult to insert the rocker shafts into the rocker shaft support portions provided in the cylinder head from the axial direction of the rocker shafts. Met.

  Further, in the device described in Patent Document 1, a holder for supporting the rocker shaft is formed separately from the cylinder head, and the holder is assembled to the cylinder head to hold the rocker shaft. In order to avoid a spark plug inserted along the center line of the cylinder hole, the structure around the valve operating device is complicated, the number of parts increases, the weight increases, the size increases, and the valve operating device is maintained.・ Many man-hours were required for the inspection.

Japanese Patent No. 4063960

The present invention relates to an invention of a rocker shaft arrangement structure of a four-stroke internal combustion engine that overcomes the disadvantages of the one described in Patent Document 1, and an object thereof is an intake valve viewed from a direction along a center line of a cylinder hole. While shortening the projection distance between the side rocker shaft and the exhaust valve side rocker shaft, the distance between the two rocker shafts can be maintained at a required value, and the rocker arm can be easily assembled while avoiding an increase in the size of the cylinder head. It is an object of the present invention to provide a rocker shaft arrangement structure in a valve operating apparatus for a four-stroke internal combustion engine that has a rocker shaft arrangement structure that can perform holding and checking of the valve gear in a short time.

The invention according to claim 1 is an intake camshaft (37) and an exhaust camshaft that respectively drive an intake valve (31) and an exhaust valve (32) provided in a cylinder head (13) of a four-stroke internal combustion engine (10). (38) has a said air intake cam (37a) and said exhaust camshaft of the stem shaft end (31a, 32a) and the intake cam shaft (37) of the intake valve (31) and said exhaust valve (32) In the rocker shaft arrangement structure (40) in which the intake rocker arm (41) and the exhaust rocker arm (42) are interposed between the exhaust cam (38a) of (38),
Wherein provided in the cylinder head (13), before Ki吸 gas rocker arm (41) end and the exhaust rocker arm (42) ends, respectively swingably pivoted to the intake rocker shaft of the (43) and The exhaust rocker shaft (44) is integrally provided between the intake valve (31) and the exhaust valve (32), and is close to each other. The cylinder head (13) and the cylinder head (13) The intake rocker shaft support portion (45) and the exhaust rocker shaft support portion arranged in the cylinder head (13) by changing the position in the direction of the cylinder hole center line (18a) in the direction connecting the supporting cylinder block (12) (46), and the intake rocker shaft (43) and the exhaust rocker shaft (44) are respectively formed with engagement recesses (43a, 44a) at predetermined positions in the axial direction. (43a, 44a) The rocker shaft arrangement structure is characterized in that a single engagement member (49) is engaged .

According to a second aspect of the invention, before Ki吸 gas rocker shaft (43) and said exhaust rocker shaft (44), in a direction parallel to the axial direction of the intake cam shaft (37) and said exhaust camshaft (38) , that is supported on each of said intake rocker shaft support portion (45) and said exhaust rocker shaft supporting portion intake rocker shaft provided in (46) fitting hole (47) and an exhaust rocker shaft fitting hole (48) The rocker shaft arrangement structure according to claim 1, wherein the rocker shaft is arranged.

According to a third aspect of the present invention, the engaging member (49) is disposed on the cylinder head (13) so as to be inclined with respect to the cylinder hole center line (18a) between the plurality of rocker shafts (43, 44). 3. The rocker shaft arrangement structure according to claim 1 , wherein the rocker shaft is arranged.

The invention according to claim 4 is a lubricating oil path (52,44) for lubricating a sliding portion between the rocker shaft (43,44) and the rocker arm (41,42) inside the rocker shaft (43,44). 53) The rocker shaft arrangement structure according to any one of claims 1 to 3, wherein 53) is formed from the insertion tip of the rocker shaft (43, 44) to the middle of the shaft.

The invention according to claim 5 injects lubricating oil toward the sliding contact surface between the intake rocker arm (41) or the exhaust rocker arm (42) and the intake cam (37a) or the exhaust cam (38a). The injection hole (56, 57) has a cylinder head (on the opposite side of the intake rocker shaft (43) or the exhaust rocker shaft (44) across the intake camshaft (37) or the exhaust camshaft (38)). The rocker shaft arrangement structure according to any one of claims 1 to 4, wherein the rocker shaft arrangement structure is provided on at least one side of 13a, 13b).

According to the rocker shaft arrangement structure (40) according to claim 1, the rocker shaft support portions (45, 46) of the valves (31, 32) between the intake valve (31) and the exhaust valve (32) are provided. Since they are arranged close to each other and vertically changed in the direction along the cylinder hole center line (18a), between the rocker shafts (43, 44) viewed from the cylinder hole center line (18a) direction. As a result of arranging the necessary distance between the two rocker shafts (43, 44) while the projection distance is shortened, the rocker shaft support portion (45) is provided without causing an increase in the size of the cylinder head (13). 46) and the rocker arm (41, 42) into the rocker shaft (43, 44), and the rocker arm (41, 42) is assembled to the rocker shaft support (45, 46). Workability is improved.
Since the common engaging member (49) can be engaged with the engaging recesses (43a, 44a) of the plurality of rocker shafts (43, 44), the number of engaging members (49) is reduced, The engagement workability can be improved and the cost can be reduced.

  According to the rocker shaft arrangement structure (40) according to claim 2, since the plurality of rocker shafts (43, 44) are parallel to each other, the rocker shaft fitting in the rocker shaft support portion (45, 46). The processing of the mounting holes (47, 48) is simplified to improve the workability of the rocker shaft support portions (45, 46), and the rocker shafts are fitted into the rocker shaft mounting holes (47, 48). The operation can be easily performed, and the workability of assembling the rocker arms (41, 42) to the rocker shaft support portions (45, 46) is improved.

According to the rocker shaft arrangement structure (40) according to claim 3 , when inserting the engaging member (49) at an angle between the plurality of rocker shafts (43, 44), Depending on the distance between the rocker shafts, it is not necessary to have a thick engaging member that engages both, and the thin engaging member (49) can be engaged with both rocker shafts (43, 44). ) Can be reduced.

The rocker shaft arrangement structure (40) according to claim 4 , wherein the inside of the rocker shaft (43, 44) is used to form a lubricating passage (52, 53) and the rocker shaft (43, 44) is inserted. By supplying lubricating oil from the tip to the sliding part between the rocker shaft (43, 44) and the rocker arm (41, 42), special lubricating oil around the rocker shaft support part (45, 46) It is not necessary to form a passage, and the plurality of rocker shafts (43, 44) can be compactly arranged by simplifying the lubricating oil supply passage around the rocker arm (41, 42).

In the rocker shaft arrangement structure (40) according to claim 5, the injection hole (56) for injecting lubricating oil toward the sliding portion between the rocker arm (41, 42) and the intake cam (37a) or the exhaust cam (38a). , 57) on the opposite side of the rocker shaft support (45, 46) with the camshaft (37, 38) in between, simplifying the lubricating oil passage around the rocker shaft (43, 44) It is possible to arrange a plurality of rocker shafts (43, 44) in a compact manner.

1 is an overall left side view of a motorcycle equipped with a front / rear V-type four-cylinder DOHC type four-stroke internal combustion engine having a rocker shaft arrangement structure according to an embodiment of the present invention. FIG. 2 is a left side view of a front / rear V-type four-cylinder four-stroke internal combustion engine mounted on the motorcycle shown in FIG. 1. FIG. 3 is a right side view in which a part of a rear cylinder of the internal combustion engine shown in FIG. 2 is omitted. FIG. 3 is a plan view of the internal combustion engine illustrated in FIG. 2. It is VV sectional drawing of FIG. It is VI-VI sectional drawing of FIG. It is VII-VII sectional drawing of FIG.

  Hereinafter, an embodiment according to the present invention will be described with reference to FIGS.

  A front / rear V-type four-cylinder DOHC type four-stroke internal combustion engine (hereinafter referred to as an internal combustion engine) 10 having a rocker shaft arrangement structure according to the present invention is mounted on a motorcycle 0 shown in FIG.

  In the present embodiment, up and down, front and back mean up and down, front and back of the motorcycle 0, and left and right mean left and right with reference to a direction facing the front of the motorcycle 0.

  A front fork 2 is provided at the front end of the main frame 1 of the motorcycle 0 so as to be able to turn left and right. A steering handle 3 is integrally attached to the upper end of the front fork 2 and the front wheel 4 is rotatable at the lower part of the front fork 2. The rear wheel 6 is pivotally supported at the rear end of a rear fork 5 that is pivotally supported by the rear portion of the main frame 1 so as to swing up and down. The rear wheel 6 is chained by power from the internal combustion engine 10. The fuel tank 8 is driven to rotate through a transmission system 7, and a fuel tank 8 is placed above the front portion of the main frame 1, and a seat 9 is provided behind the fuel tank 8.

  As shown in FIGS. 2 and 3, in the internal combustion engine 10, a cylinder block 12, a cylinder head 13, and a head cover 14 are sequentially stacked on the crankcase 11, and these are integrally coupled to each other. An oil pan 15 is integrally attached under 11.

  As shown in FIG. 6, a crankshaft 17 oriented in the left-right direction is rotatably supported via a bearing portion 16 at a joint portion between the cylinder block 12 and a crankcase 11 (not shown) below the cylinder block 12. In addition, a piston 19 is slidably fitted in the cylinder hole 18 of the cylinder block 12, and a large-diameter end 20a of the connecting rod 20 is rotatably coupled to the crankshaft 17, and a piston fitted to the piston 19 A small diameter end portion 20b of the connecting rod 20 is rotatably coupled to the pin 21, and the crankshaft 17 is rotationally driven by the reciprocating motion of the piston 19.

  In the cylinder head 13 of the internal combustion engine 10, as shown in FIGS. 1 to 5, an intake port 22 communicating with the cylinder hole 18 is formed inside the V bank, and a cylinder hole is formed outside the V bank. 1 is formed, and the air cleaner 24 shown in FIG. 1 located in the V bank is connected to the intake ports 22 of the front and rear cylinder heads 13 and is located outside the front and rear of the V bank. The exhaust pipe 25 is connected to the exhaust ports 23 of the front and rear cylinder heads 13, and the front exhaust pipe 25a located at the front bypasses the lower side of the internal combustion engine 10 in FIG. 1 and seats together with the rear exhaust pipe 25b located at the rear. The exhaust generated in the internal combustion engine 10 is exhausted to the rear of the motorcycle 0.

  As shown in part in FIGS. 5 and 6, in the valve operating apparatus 30, a pair of left and right intake valves 31 are arranged inside the V bank for each cylinder hole 18, and left and right outside the V bank. A pair of exhaust valves 32 are disposed, and an intake valve 31 that opens and closes an intake opening 22a of an intake port 22 that opens into the cylinder hole 18 is slidably fitted to the cylinder head via a valve guide 33, and exhaust gas. An exhaust valve 32 that opens and closes the exhaust opening 23a of the port 23 is also slidably fitted to the cylinder head 13 via the valve guide 33, and is attached to the stem shaft end 31a of the intake valve 31. A valve spring 36 is interposed between a spring seat 35 provided on the head 13, and a spring retainer 34 attached to the stem shaft end 32 a of the exhaust valve 32 and a spring provided on the cylinder head 13. A valve spring 36 is interposed in the seat 35, and the valve face 31b of the intake valve 31 and the valve face 32b of the exhaust valve 32 are separated into an intake opening 22a and an exhaust opening 23a by the extension spring force of the valve spring 36. The intake port 22 and the exhaust port 23 are sealed in close contact with each other.

  As shown in FIG. 5, the intake camshaft 37, exhaust gas is provided via a bearing (not shown) on the mating surface of the cylinder head 13 and the head cover 14 on the extension line of the stem shaft ends 31 a, 32 a of the intake valve 31 and exhaust valve 32. Each camshaft 38 is rotatably supported, and a cam gear (not shown) is integrally mounted on the right ends of the intake camshaft 37 and the exhaust camshaft 38. The cam gear is attached to the crankshaft 17 via a gear train (not shown). The cam gear and the exhaust camshaft 38 are rotationally driven at a half rotational speed of the crankshaft 17.

  In the rocker shaft arrangement structure 40 (see FIG. 5) interposed between the stem shaft ends 31a, 32a of the intake valve 31 and the exhaust valve 32 and the intake cam shaft 37, the intake cam 37a of the exhaust cam shaft 38, and the exhaust cam 38a. An intake rocker shaft support portion 45 and an exhaust rocker shaft support portion 46 are integrated into the cylinder head 13 in parallel with the left and right crankshaft 17 in each cylinder hole 18 in the intake side cylinder head portion 13a adjacent to the intake port 22. As shown in FIG. 7, the intake rocker shaft support portion 45 and the exhaust rocker shaft support portion 46 are formed on the intake side notch 45a on the intake valve 31 side. 41a is inserted, and a pivot base 42a of the exhaust rocker arm 42 is inserted into the exhaust-side notch 46a on the exhaust valve 32 side, and the intake rocker shaft support 45 receives the intake air in parallel with the crankshaft 17. The intake rocker shaft 43 inserted into the rocker shaft fitting hole 47 passes through the pivot base 41a of the intake rocker arm 41 and is parallel to the crankshaft 17 to the exhaust rocker shaft fitting hole 48 of the exhaust rocker shaft support 46. As shown in FIG. 5, the exhaust rocker shaft 44 inserted into the shaft passes through the pivot base 42 a of the exhaust rocker arm 42 at a position closer to the cylinder block 12 side than the intake rocker shaft 43.

  As shown in FIG. 5, the intake rocker shaft support portion 45 is engaged with an engagement member 49 having a male screw 49 a formed at the tip, and this engagement member 49 is connected to the intake rocker shaft 43. The engagement recess 43a engages with the engagement recess 44a of the exhaust rocker shaft 44, and the intake rocker shaft 43 and the exhaust rocker shaft 44 are prevented from falling off from the intake side cylinder head portion 13a by the engagement member 49. ing. The head of the engagement member 49 is formed with a regular hexagonal hole in cross-sectional shape, and the engagement member 49 can be screwed by inserting a regular hexagonal tip of a tool (not shown) into the hole. It is like that.

  In FIG. 6 in which the cylinder head 13 in front of the V bank is cut along the center line 18a (see FIG. 5), plug insertion holes 61 are formed in the cylinder heads 13 along the center lines 18a of the cylinder holes 18, respectively. A cylindrical plug insertion cylinder 60 is inserted into the plug insertion hole 61, and a spark plug (not shown) is inserted into the plug insertion cylinder 60 and the plug insertion hole 61. A lubricating oil passage 62 is formed between the inner circumferential surface of the plug insertion hole 61 and the outer circumferential surface of the plug insertion cylinder 60 with a narrow gap as shown in FIG.

  In FIG. 7, an opening 51a of a rocker shaft lubricating oil passage 51 is provided on the inner side of the V bank adjacent to the right side of the vehicle body in the cylinder head 13, and the opening 51a is connected to the casing of the internal combustion engine 10 via a pipe (not shown). It is connected to a discharge port of a lubricating oil pump (not shown) provided in the rank case 11.

The intake rocker shaft 43 inserted into the intake rocker shaft support portion 45 and the exhaust rocker shaft 44 inserted into the exhaust rocker shaft support portion 46 are respectively connected to the intake rocker shaft lubricating oil passage 51 and the intake side lubricating oil passage 51 52 and an exhaust side lubricating oil passage 53 are formed, and the lubricating oil discharged from the lubricating oil pump passes through the rocker shaft lubricating oil passage 51 and the lubricating oil passage 62, and the intake side lubricating oil of the intake rocker shaft 43 Flows into the passage 52 and the exhaust-side lubricating oil passage 53 of the exhaust rocker shaft 44, and is supplied to the sliding contact portion between the intake rocker arm 41 and the intake rocker shaft 43 and the sliding contact portion between the exhaust rocker arm 42 and the exhaust rocker shaft 44. These sliding portions are lubricated.

  Further, as shown in FIG. 5, the intake side cylinder head portion 13a and the exhaust side cylinder head portion 13b located on the front and rear outer sides of the cylinder head 13 are connected to the intake port of the lubricating oil pump (not shown). A rocker arm lubricating oil passage 54 and an exhaust rocker arm lubricating oil passage 55 are provided, and lubricating oil is provided from the intake rocker arm injection hole 56 of the intake rocker arm lubricating oil passage 54 to a sliding contact portion between the intake cam 37a and the intake rocker arm 41. Is injected from the exhaust rocker arm injection hole 57 of the exhaust rocker arm lubricating oil passage 55 to the sliding contact portion between the exhaust cam 38a and the exhaust rocker arm 42.

The lubricating oil pumped from the lubricating oil pump to the rocker shaft lubricating oil passage 51 supports the intake rocker shaft support 45 and the exhaust rocker shaft support so that the outer surface of the plug insertion tube 60 and the plug insertion tube 60 can be loosely fitted. Since the lubricating oil passage 62 formed in the space with the inner peripheral surface of the plug insertion hole 61 formed in the portion 46 is formed, the intake rocker shaft support portion 45 and the exhaust rocker shaft support portion 46 in the cylinder head 13 are formed. The intake rocker shaft 43 is inserted into the intake rocker shaft fitting hole 47 and the exhaust rocker shaft fitting hole 48, and the intake side lubricating oil passage 52 and the exhaust side lubricating oil passage 53 in the exhaust rocker shaft 44 are supplied to The sliding contact portions of the rocker shaft 43, the exhaust rocker shaft 44, the intake rocker arm 41, and the pivot base portions 41a of the exhaust rocker arm 42 are reliably lubricated.

As mentioned above, although the rocker shaft arrangement structure of the four-stroke internal combustion engine of the internal combustion engine of the present invention has been described by one embodiment, it is a matter of course that the present invention is not limited to this aspect. In the scope of the gist, this includes those implemented in various ways.

For example, the internal combustion engine is not limited to a four-cylinder rocker arm, and may be other than the V type and the number of cylinders is not limited. Note that the present invention can be similarly applied to an internal combustion engine in which the left and right arrangements of the internal combustion engine are opposite to those shown in the above embodiment.

The internal combustion engine provided with the rocker shaft arrangement structure of the four-stroke internal combustion engine of the internal combustion engine of the present invention is not limited to being mounted on a motorcycle, but may be mounted on various small vehicles such as buggy cars. Furthermore, although it may be a stationary internal combustion engine, the present invention can be implemented particularly effectively in an internal combustion engine for a small vehicle such as a motorcycle that requires downsizing of the internal combustion engine.

DESCRIPTION OF SYMBOLS 0 ... Motorcycle, 1 ... Main frame, 2 ... Front fork, 3 ... Steering handle, 4 ... Front wheel, 5 ... Rear fork, 6 ... Rear wheel, 7 ... Chain transmission system, 8 ... Fuel tank, 9 ... Seat, 10 ... internal combustion engine, 11 ... crankcase, 12 ... cylinder block, 13 ... cylinder head, 14 ... head cover, 15 ... oil pan, 16 ... bearing part, 17 ... crankshaft, 18 ... cylinder hole, 19 ... piston,
20 ... Connecting rod, 21 ... Piston pin, 22 ... Intake port, 23 ... Exhaust port, 24 ... Air cleaner, 25 ... Exhaust pipe,
30 ... Valve system, 31 ... Intake valve, 32 ... Exhaust valve, 33 ... Valve guide, 34 ... Spring retainer, 35 ... Spring seat, 36 ... Valve spring, 37 ... Intake camshaft, 38 ... Exhaust camshaft, 39 ... Cam gear,
40 ... Rocker shaft arrangement structure, 41 ... Intake rocker arm, 42 ... Exhaust rocker arm, 43 ... Intake rocker shaft, 44 ... Exhaust rocker shaft, 45 ... Intake rocker shaft support, 46 ... Exhaust rocker shaft support, 47 ... Intake Rocker shaft fitting hole, 48 ... exhaust rocker shaft fitting hole, 49 ... engagement member,
50 ... connecting portion, 51 ... rocker shaft lubricating oil passage, 52 ... intake side lubricating oil passage, 53 ... exhaust side lubricating oil passage, 54 ... intake rocker arm lubricating oil passage, 55 ... exhaust rocker arm lubricating oil passage, 56 ... intake Rocker arm injection hole, 57 ... exhaust rocker arm injection hole,
60 ... Cylinder for plug insertion, 61 ... Hole for plug insertion, 62 ... Lubrication oil passage

Claims (5)

An intake camshaft (37) and an exhaust camshaft (38) respectively driving an intake valve (31) and an exhaust valve (32) provided in a cylinder head (13) of a four-stroke internal combustion engine (10), Stem shaft ends (31a, 32a) of the intake valve (31) and the exhaust valve (32), the intake cam (37a) of the intake camshaft (37), and the exhaust cam (38a) of the exhaust camshaft (38) Rocker shaft arrangement structure (40) in which an intake rocker arm (41) and an exhaust rocker arm (42) are interposed between
An intake rocker shaft (43) and an exhaust rocker that are provided on the cylinder head (13) and pivotally support the end of the intake rocker arm (41) and the end of the exhaust rocker arm (42), respectively. The axis (44),
A cylinder block (12) that is integrally provided between the intake valve (31) and the exhaust valve (32), is close to each other, and supports the cylinder head (13) and the cylinder head (13); An intake rocker shaft support portion (45) and an exhaust rocker shaft support portion (46) disposed in the cylinder head (13), with the position being changed in the direction of the cylinder hole center line (18a) in the direction connecting
Comprising
The intake rocker shaft (43) and the exhaust rocker shaft (44) are respectively formed with engagement recesses (43a, 44a) at predetermined positions in the axial direction, and the plurality of engagement recesses (43a, 44a) are single. A rocker shaft arrangement structure characterized in that the engagement member (49) is engaged.   The intake rocker shaft support portions (45) are arranged in a direction in which the intake rocker shaft (43) and the exhaust rocker shaft (44) are parallel to the axial directions of the intake camshaft (37) and the exhaust camshaft (38), respectively. And an exhaust rocker shaft fitting hole (48) provided in the exhaust rocker shaft support portion (46) and an exhaust rocker shaft fitting hole (48). Placement structure.   The engagement member (49) is disposed on the cylinder head (13) so as to be inclined with respect to the cylinder hole center line (18a) between the plurality of rocker shafts (43, 44). The rocker shaft arrangement structure according to 1 or 2.   Lubricating oil passages (52, 53) for lubricating sliding portions between the rocker shafts (43, 44) and the rocker arms (41, 42) are provided inside the rocker shafts (43, 44). 43. The rocker shaft arrangement structure according to any one of claims 1 to 3, wherein the rocker shaft arrangement structure is formed from the insertion tip of 43, 44) to the middle of the shaft.   There are injection holes (56, 57) for injecting lubricating oil toward the sliding contact surface between the intake rocker arm (41) or the exhaust rocker arm (42) and the intake cam (37a) or the exhaust cam (38a). , At least one side of the cylinder head portion (13a, 13b) on the opposite side of the intake rocker shaft (43) or the exhaust rocker shaft (44) across the intake camshaft (37) or the exhaust camshaft (38) The rocker shaft arrangement structure according to any one of claims 1 to 4, wherein the rocker shaft arrangement structure is provided.

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