JPH0419311A - Engine oil pan gasket - Google Patents

Abstract

PURPOSE:To prevent oil raise in a crankcase consequent upon internal pressure becoming higher by providing a protrudent portion, which protrudes toward the oil pan inner side along the contacting surface, on an oil pan gasket all around the oil pan and also forming an opening in the center portion which is the inner side of the protrudent portion. CONSTITUTION:An oil pan gasket 220 is fitted between the joining surfaces 218, 219 of both an oil pan 93 and a lower case 69a in a manner so as to close up the space between the joining surfaces 218, 219 tightly. The oil pan gasket 220 is a moulded thin metal plate and is formed in a width wider than each joining surfaces 218, 219, while a protrudent portion 220b, which protrudes in an appropriate length toward the inner side of the oil pan 93, is formed on the inner side of the outside circumference (outer side of the 2 point chain line) 220a joining each joining surfaces 218, 219 along each joining surfaces 218, 219 in one unit with the outside circumference. The oil pan gasket 220 is wider than each joining surfaces 218, 219 while the width of the protrudent portion 220b is nearly uniform. An opening portion 220c is formed in center portion, which is the inner side of the protrudent portion 220b, so as lubrication oil returns to the oil pan 93 from the opening portion 220c.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an oil pan gasket that is interposed between the joint surfaces of a crankcase and an oil pan that constitute an engine to seal the joint surfaces. It is.

[Prior art] As this type of oil pan gasket,
As shown in Japanese Patent No. 8214, the upper part of the lubricating oil stored in the oil pan is depressed so as to be close to the oil surface, and the inside of the oil pan is passed through numerous minute holes formed in this depressed part. Some oil pumps are designed to supply lubricating oil stably to the engine, etc. by returning lubricating oil to the engine and suppressing the waving phenomenon that occurs on the oil surface using a depressed portion.

[Problems to be Solved by the Invention] According to the above-mentioned glass sill pan gasket, the recessed portion also serves as a so-called oil filter, so when the engine is operated at medium or high speeds, the recessed portion inside the glass sill pan gasket is It is assumed that the lubricating oil does not return quickly and the amount of lubricating oil in the oil pan gradually decreases. Furthermore, as the internal pressure within the crankcase increases, a phenomenon occurs in which lubricating oil rises along the inner wall of the oil pan (so-called oil rising).

The present invention has been made in view of the above circumstances, and is
To provide an oil pan gasket for an engine that secures the amount of lubricating oil returned into the oil pan even during operation at high rotational speeds, effectively suppresses oil leakage, and ensures a stable supply of lubricating oil. The purpose is

[Means for Solving the Problems] The present invention is an oil pan gasket made to achieve the above-mentioned object, in which a suitable gasket is provided inside the oil pan along between the joint surfaces of the crankcase and the oil pan. The oil pan is characterized in that it includes a lengthwise protrusion extending all the way around the oil pan, and that an opening is formed in the center, which is the inside of the protrusion.

[Function] According to the engine oil pan gasket of the present invention, even when the engine is operated at medium to high speeds, the lubricating oil that has finished lubrication reliably and quickly returns into the oil pan through the opening. Further, even if the lubricating oil in the oil pan rises along the wall surface of the oil pan as the internal pressure of the crankcase increases, it hits the protrusion and is prevented from rising any further. Further, when the bubbles contained in the lubricating oil in the oil pan hit the protrusion, the bubbles become smaller or are crushed and disappear.

As described above, a constant amount of lubricating oil is always stored in the oil pan, and as a result, a stable supply of lubricating oil to the engine, transmission, etc. is achieved.

[Embodiment 1] Hereinafter, an example in which the present invention is applied to a motorcycle engine will be described with reference to the drawings. In the description, directions such as front and back and left and right are relative to a single unit.

1 and 2 show a front view and a side view of the motorcycle 1, respectively.

This motorcycle 1 includes a body frame 2, a pair of left and right front forks 3 rotatably supported at the front end of the body frame 2, and a steering handle 4 attached to the upper ends of these front forks 3. , a front wheel 5 rotatably supported by a front fork 3, a fork 6 rotatably supported by the vehicle body frame 2, and a rear wheel 7 rotatably supported by the rear end of the rear fork 6. A water-cooled engine 8 according to this embodiment supported by the vehicle body frame 2, a radiator 9 also supported by the vehicle body frame 2, a fuel tank 10 disposed on the upper part of the vehicle body frame 2, and this fuel tank 10. The vehicle includes a driver's seat 118 and a passenger trunk 12 arranged at the rear of the vehicle body, and the front part of the vehicle body includes a front cowl 13 and an under cowl 1.
4, the rear part of the vehicle body is covered by a cowl 15.

The vehicle body frame 2 includes a head vibrator 16 at the front end,
A front engine hanger 17 is divided into left and right parts and extends rearward and diagonally downward, and at the bottom thereof, a front engine hanger 17 also extends rearward and diagonally downward.
Also, a pair of left and right main frames 19 each having a hollow square cross section integrally provided with a rear engine hanger 18, front and rear arm portions 20a120b, and a bracket portion 20 extending downward.
c is formed, and the front arm portion 20a is attached to each main frame 19.
A pair of left and right hollow subframes 20 connected to the rear end
, an upper cross member 21 and a lower cross member 22 that extend laterally between the upper and lower parts of each bracket portion 20c of these sub-frames 20 and are provided integrally with the sub-frame 20; The V-rail consists of a pair of left and right upper rails 23a and lower rails 23b bolted to the rear arm portion 20b8 and the bracket portion 20c of the subframe 20, respectively, and extending rearward and diagonally upward, the rear ends of which are welded to each other. It consists of a trail 23. The main frame 19 and the front arm portion 20a of the sub-frame 20 are connected to each other via a joint material 24 that is inserted into the inside of the two and welded.

The head vibrator 16 that constitutes the vehicle body frame 2 includes:
A steering stem 26 with a lower bridge 25 integrally provided at its lower end is inserted so as to be rotatable around an axis, and the head pipe 16 of this steering stem 26 is
A top bridge 27 is fixed to the upper end portion protruding from the top.

The front fork 3 includes a bottom case 28 and an inner tube 29 slidably inserted into the bottom case 28 via a cushion (path shown), and the inner tube 29 is connected to the top bridge 27 and the lower bridge. It is inserted and fixed at both ends of 26. This results in
The front fork 3 is integrated with a steering stem 26 via a top bridge 27 and a lower bridge 25, and is rotatable.

The handlebars 4 are a pair of left and right handlebars 30.
and a grip 31 attached to the handle par 30, and the end of the handle par 30 is fitted and fixed to the upper end protruding from the top bridge 27 of each front fork 3.

The front wheel 5 is a wheel 3 having an axle 32 at its axis.
A tire 34 is attached to the outer circumference of the axle 3.
2 are supported by the lower ends of the bottom cases 28 of each 70-ton oak 3. Note that a front fender 35 that covers the upper part of the front wheel 5 is supported by the left and right bottom cases 28 .

Rotors 37 constituting a front disc brake device 36 are fixed coaxially and integrally with the wheel 33 on both left and right sides of the wheel 33 of the front wheel 5, respectively. The front disc brake device 36 includes this rotor 37 and a brake caliper 39 that is fixed to the rear side of the bottom case 28 of each front fork 3 via a stay 38 and brakes the rotation of the rotor 37 by frictional force while sandwiching the rotor 37 in the operating state. A brake lever 41 and collar 111 are attached to the handlebar 30 of the right handlebar 4 and actuate the brake caliper 39 via a cable 40.

The rear fork 6 has a pair of left and right fork parts 43 extending rearward from a base part 42 at its front end.
2 is pivotally supported by a pivot 44 provided on the bracket part 20c of the sub-frame 2o, so that the 7-axis part 43 can swing up and down.

The rear wheel 7 has a slightly larger diameter than the front wheel 5, and like the front wheel 5, a tire 47 is attached to the outer periphery of a wheel 46 having an axle 45 at its center, and both ends of the axle 45 are By being supported by the rear end of the 7-hook portion 43 of the rear fork 6, it swings together with the rear fork 6.

The vibration that the rear wheel 7 receives from the road surface is buffered by the reaction unit 48. The reaction unit 4B includes a damper 49, a spring 50, etc., and its upper end is connected to the upper cross member 21 by a stay 51.
A cushion main body 52 is pin-coupled to the lower cross member 22 via a pin, and one end thereof is pin-coupled to the lower cross member 22; It is comprised of a stay 54 fixed to the lower part of the seven oak part 43 of the rear fork 6 near the center front, and cushioning arms 55 each pin-coupled to the lower end of the cushion body.

The rear wheel 7 is also equipped with a rear disc brake device 56 similar to the 70-point disc brake device 36 of the front wheel 5.

This rear disc brake device 56 is fixed to the right side of the wheel 46 coaxially and integrally with the wheel 46, and includes a tar rotor 57 and a right fork portion 4 of the rear fork 6.
A brake caliper 59 is fixed to the lower side of the rotor 57 via a stay 58 and brakes the rotation of the rotor 57 by frictional force in an operating state. It consists of a brake pedal (as shown) to be operated. A torque rod 60 is mounted between the front end of the brake caliper 59 and the lower part of the pivot 44 in the right bracket part 20c of the subframe 20. Note that the rear fork 6 has a rear guard 61 that rises from the center of the base 42 in the left-right direction while gently curving rearward and diagonally upward and covers the upper front side of the rear wheel 7.
are integrated.

Further, a chain sprocket 62 is fixed coaxially to the left side of the wheel 46 of the rear wheel 5, and a drive chain 63, which will be described later, is wound around the chain sprocket 62. Furthermore, a chain cover 64 that covers the upper rear part of the drive chain 63 and the upper part of the chain sprocket 62 is fixed to the left fork portion 43 of the rear fork 6 .

The engine 8 includes a cylinder block 68 consisting of a cylinder block body 65, a cylinder head 66, and a cylinder head cover 67, and a crank case 69 connected to the cylinder block 68. 4 cylinders 70
It is a parallel four-cylinder, four-stroke engine with four cylinders arranged in parallel. This engine 8 has a cylinder block 68
With the cylinder block 68 tilted slightly forward, the cylinder block 68 is attached to the front engine hanger 17 and the rear engine hanger 1B of the main frame 19, and also to the crankcase 69.
Both sides of the rear portion are the bracket portions 2 of the subframe 20.
0c, and is supported by the vehicle body frame 2 by being bolted to each of them.

A carburetor 71 is connected to the rear of the cylinder block 68 of the engine 8 to supply air-fuel mixture into the cylinder block 68 by the suction action of the engine 8 .

Further, each cylinder 7 is provided at the front of the cylinder block 68.
An exhaust pipe 72 is connected to each exhaust pipe 72, and these four exhaust pipes 72 (from the left side of the vehicle body are number 1 exhaust pipe 72a, number 2 exhaust pipe 72b, number 3 exhaust pipe 72c and number 14 exhaust pipe 72d).
extend downward from the connecting end to the cylinder block 68 and are aligned below the engine 8, and are further bent and extend rearward along the lower surface of the crankcase 69, so that one Collecting pipe 7
It is summarized in 3. The collecting pipe 73 rises diagonally backward to the right, with its tip disposed on the right side of the rear wheel 7, and has a cylindrical shape extending diagonally upward so as to be in line with the rear end of the collecting pipe 73. A silencer 74 is attached.

Note that, as shown in FIG. 2, each of the exhaust pipes 72a to 72d is connected to the right side of the first exhaust pipe 72a at a position slightly left of the center line of the unit below the engine 8, and connects to the fourth exhaust pipe 7.
2d are arranged, and the second exhaust pipe 72b is in contact with the lower side of these.
A No. 3 exhaust pipe 72c is arranged in contact with the No. 2 exhaust pipe 72b and the No. 4 exhaust pipe 72d, and its cross section as a whole has a parallelogram shape tilted to the left (to the right in Fig. 2). It is summarized.

Note that the engine 8 will be explained in detail later.

The radiator 9 is an oblong rectangular cross 70-type in which a cooling water inflow tank 76 is connected to the right side of the core 75 and an outflow side tank 77 is connected to the left side of the core 75. Placed in the front, the main 7 lanes 1
9 and the front engine hanger 17.

The fuel tank IO is disposed above each main frame 19 and between each subframe 20 and is fixed to these frames 19, 20. A recess lOa is formed in the lower surface of the front side of the fuel tank lO, and an air cleaner 78 is accommodated in this recess 10a. An air suction pipe 79 bent downward is connected to the front part of the air cleaner 78, and the carburetor 71 is connected to the rear part of the air cleaner 78.
A suction lower 1a is inserted.

The front cowl 13 is formed into a streamlined shape from the front of the head pipe 16 toward the rear, and covers both sides of the front fork 3 and both sides of the radiator 9 and the cylinder block 68 of the engine 8. is provided with a notch 13a to avoid interference with the handle 4, and furthermore, a notch 13a which is approximately U-shaped when viewed from the front is provided at the upper end of the front part.
3b, and a transparent screen 80 that extends curvedly above the top bridge 27 of the vehicle body frame 2 and the handlebar 4 to cover the upper side of the front fork 3 is integrally provided here.

The front end of the front cowl 13 is supported by a cowl stay 81 that is fixed to the head pipe 16 and extends forward, and the lower part of the rear part of the screen 80 is fixed to the main frame 19 and rises upward and then moves forward. It is supported by an extending cowl stay 82, and both sides are fixed to the main frame 19 of the vehicle body frame 2 with bolts or the like.

Air inlet ports 83 are formed at the front positions of both upper corners of the radiator 9 in the front cowl 13 . Further, two rectangular headlight mounting holes 84 are formed side by side in the center of the front end, and these headlight mounting holes 84 are provided with the cowl stay 81.
A rectangular headlight 85 fixed at the tip of each is provided. Further, a meter unit 86 is fixed to the upper center of the cowl stay 81, with a speedometer, an engine tachometer, etc. attached thereto.

Further, direction indicators 87 are attached to both sides of the front portion of the front cowl 13 at positions below the air inlet 83.

The under cowl 14 has a substantially U-shaped cross section and continuously covers both sides of the crankcase 69 of the engine 8 and the exhaust pipe 72 from the lower end of the front cowl 13, and is fixed to the front cowl 13 with bolts or the like.

The rear cowl 15 is formed to cover the sides and top of the seat rail 23, which is made up of two upper rails 23a and two lower rails 23b on the left and right sides, and has an integrally formed bulge 15a projecting upward at its rear part. It has
A fitting means I such as a hook is attached to each of the rails 23a123b.

A recess 88 formed by the fuel tank 10 and the bulging portion 15a in the rear cowl 15 is a seating position for the driver of the motorcycle*1, and the upper surface of the rear cowl 15 at this position is provided with a seat for the driver. A seat 11 is provided, and the occupant sound sheet 12 is provided on the upper surface of the bulge portion 15a.

A battery 89 is disposed under the rear cowl 15 where the driver's seat 11 is provided.A tail lamp 90 that also serves as a stop light is attached to the rear end of the rear cowl 15. A rear fender 91 is provided that extends diagonally downward, and direction indicators 92 are attached to both sides of the upper part of the rear fender 91.

Next, the engine 8 will be described in detail with reference to FIGS. 3 to M5.

This engine 8 has a cylinder block main body 6 as described above.
5. Cylinder head 66 and cylinder head cover 6
Cylinder block 68 consisting of 7 and crank case 6
9, and the crank case 69 has an upper case 69a.
and lower case 69b are separably joined, and upper case 69a and cylinder block main body 65 are integrally cast. Further, an oil pan 93 is joined below the lower case 69b.

3 and 4 show a fixing post 94 provided at the rear of the cylinder block body 65 and for fixing the main frame 19 to the rear engine hanger 18, and an upper case 6
9a and a fixing post 95 provided at the rear of the lower case 69b to the bracket portion 20c of the subframe 20 is shown.

Four flips 70 are arranged in parallel on the cylinder block 6B, and inside these cylinders 70 are cast sleeves 9.
A piston 97 is slidably fitted through the piston 6. These pistons 97 are rotatably supported within the crankcase 69 via connecting rods 98, and a crank sprocket 99 is formed at one end (the right end in this case), and an oil hole 100a for supplying lubricating oil is formed in the journal portion 100. It is connected to a crankshaft 101, and is configured to reciprocate up and down within the cylinder 70 by rotation of the crankshaft 101.

As shown in Figure VG3, each flip head 66 is provided with a combustion chamber 102 formed by this flip head 66 and each piston 97 that has reached the top dead center. spark plug 103
Further, an intake passage 104 and an exhaust passage 105 are formed which communicate each combustion chamber 102 with the outside. The intake port 106 and the exhaust port 107, which are the openings of each combustion chamber 102 in each of these passages 104 and 105, have two openings.
An intake valve 108 and an exhaust valve 109 are provided above the cylinder block body 65 to open and close each port 106, 107, respectively.

These intake valves 1088 and exhaust valves 109 include a valve stem 110 having an umbrella-shaped valve body 110a that actually opens and closes each of the ports 106 and 107, and a valve stem 110 having an umbrella-shaped valve body 110a that actually opens and closes each of the ports 106 and 107. port 1
06. Valve spring 11 that closes 107
1 and a cylindrical valve lifter 112 attached to the upper end of the valve stem 110.
is the valve guide 11 fitted into the cylinder head 66
3 is slidably inserted into.

An intake camshaft 1 that operates each intake valve 108 and each exhaust valve 109 is mounted on the syringe head 66.
14 and an exhaust side camshaft l15 are arranged parallel to the crankshaft 101.

These camshafts 114 and 115 are connected to the fastening bolts 11
It is rotatably supported around the axis by a bearing cap 117 fixed to the cylinder head 66 at 6,
An intake side cam 11g and an exhaust side cam 119 are integrally molded on the circumferential surface thereof in correspondence with each intake valve 10B and each exhaust valve 109, and furthermore, on the right end portion, a bearing cap 117 is engaged. A protrusion 120 that restricts movement in the axial direction is integrally formed.

Furthermore, cam sprockets 121 and 122 are integrally provided at the right end of each camshaft 114 and 115, and a cam chain 123 is wound around these cam sprockets 121 and 122 and the crank sprocket 99 of the crankshaft 101, crankshaft 71-10
1, each camshaft 114, 115 rotates.

As these camshafts 114 and 115 rotate, the peripheral surfaces of each cam 118 and 119 slide into valve lifter 112 of each intake valve 108 and each exhaust valve 109, respectively, causing the valve stem 110 to reciprocate up and down. , whereby the intake port 106 and the exhaust port 107 are opened and closed.

As shown in FIG. 4, a cam chain guide 124 is disposed on the outer circumferential side of the cam chain 123 between the cam sprocket 122 of the exhaust side camshaft and the crank sprocket 99, and The cam chain 123 is located on the outer peripheral side of the cam chain 123 between the cam chain 121 and the crank sprocket 99.
A cam chain tensioner 125 is provided to suppress flapping.

The cam chain guide 2 125 has one end pin-coupled to the cylinder rad 66 so that it can swing.
23, and the piston holder 1 is disposed on the cylinder block body 65.
27, and a piston 128 that constantly presses the swinging end of the tensioner slipper 126 against the cam chain 123 using hydraulic pressure.

The exhaust lower 1 of the carburetor 71 has a piston valve 129 at the outer opening of the intake passage 104.
b are connected by a cab inulator 130, and the connection end of the exhaust pipe 72 (72a to 72d) is connected to the stud port 1 at the external opening of the exhaust passage 105.
31, respectively.

Note that the cylinder head cover 67 that is joined onto the cylinder head 66 has a cam chain chamber 123 in which the inside of the cylinder head cover 67 and the cam chain 123 are arranged.
A breather chamber 132 is provided which communicates with the inside of the crankcase 69 via a and separates oil contained in blow-by gas generated inside the crankcase 69. In addition,
The blow-by gas from which oil has been separated in the breather chamber 132 is discharged into the atmosphere from an air guide pipe (not shown) connected to the breather chamber 132.

Further, as shown in FIG. 5, the crankshaft 7 and 10
At the right end of 1, there is an ignition timing detection mechanism consisting of a pulser rotor 133 that rotates integrally with the crankshaft lO1, and a pulse generator 135 supported by a generator fixed over the crankcase 69. 13
6 is provided.

Further, at the left end of the crankshaft 101, there is a rotor 137 that rotates integrally with the crankshaft 101, and an AC generator cover 13 fixed to the crankcase 101.
An AC generator 140 having a stator 139 supported by a stator 139 is provided.

Further, a starter motor driven sprocket 141 is attached to the crankshaft 101 inside the AC generator 140 via a needle bearing. This starter motor driven sprocket 141 is connected to the rotor 137 via a one-way clutch 142, and is connected via a chain 145 to a starter motor drive sprocket 144 of a starter motor 143 disposed on the left side in the upper case 69a. connected.

Here, the cooling system of the engine 8 by the radiator 9 will be briefly explained with reference to FIGS. 1 to 4.

In the lower case 69b of the crankcase 69, a crankshaft 101
A water pump 147 whose impeller 146 rotates as the water pump rotates is provided, and three connecting pipes 148, 149, and 150 are branched and connected to the water pump 147. Further, a connecting pipe 151 is integrally provided on the front left side of the cylinder block body, and branch pipes 152 and 153 are connected to this connecting pipe 151. Furthermore, a connecting pipe 154 facing upward is provided on the rear right side of the cylinder head 66.

The connecting pipe 148 is connected to the inflow side radiator hose 155.
The outflow lower 7 of the outflow side tank 77 of the radiator 9 via
a, the connecting pipe 149 is connected to the one branch pipe 152 via the water pipe 156, and the connecting pipe 15
0 is the other branch pipe 153 via the water pipe 157
It is connected to the. This water pipe 157 is connected to an oil filter 15 in a lubricating oil supply device 158, which will be described later.
9 has passed through case 159a. In addition, the connecting pipe 15
4 is connected to the inflow lower a of the inflow side tank 76 of the radiator 9 via the outflow side radiator hose 160.

By the operation of the water pump 147, the cooling water flows from the water jacket 65a formed inside the cylinder block main body 65 through the radiator 9 → the inflow side radiator hose 155 → each water pipe 156 and 157.
Water jacket 6 formed within cylinder head 66
6a, flows through a circulation path from the outflow side radiator hose 160 and returns to the radiator 9, and cools the engine 8.

Next, a transmission 161 connected to the engine 8 and a change mechanism 16 that switches and controls the transmission 161.
2 will be explained.

As shown in FIG. 5, the transmission 161 includes needle bearings 164, 165 and pawl bearings 1 in a transmission case 163 integrated with the lower case 69b of the crankcase 69, in parallel with the crankshaft 101, and in parallel with the crankshaft 101.
A hollow main shaft 168 and a counter shaft 169 (both spline shafts) are rotatably disposed via shafts 66 and 167, and these shafts 16g, 16
transmission gear groups 170 that are provided at each of the transmission gears 9 and mesh with each other;
a-17Of and 171a-171f, and are provided at the right end of the main shaft 16g, and the crankshaft 10
A primary driven gear 173 that meshes with the primary drive gear 172 of the main shaft 1
The clutch mechanism 174 is provided at the right end of the main shaft 168, and the operating rod 175 is inserted into the main shaft 168 so as to be movable in the axial direction and connects and disconnects the clutch mechanism 174.

The space between the main shaft 16g and the operating rod 175 and the inside of the counter shaft 169 are respectively used as lubricating oil supply paths 176 and 177, and the main shaft 168
and the countershaft 169 has a supply passage 176.1
77 to the outer circumferential surface, transmission gear groups 170a-17O
f and 171a to 17lb, clutch mechanism 174
Oil holes 178 and 179 for supplying lubricating oil are formed respectively.

According to this transmission 161, the power of the engine 8, that is, the rotation of the crankshaft 101, is transmitted to the main shaft 168 via the primary-driven gear 173 and the clutch mechanism 174, and then to each transmission gear group 17.
0a to 17Of and 171a to 171f, and is further transmitted to the rear wheel 7 from the driven sprocket 180 fixed to the left end of the countershaft 169 via the drive chain 63. It has become. .

The primary driven gear 173 is the main gear 1
73a and sub gear 173b, these gears 1
Although the sleeves 73a and 173b can rotate relative to each other, their rotation is regulated by a damper spring 181 to suppress backlash when meshing with the primary drive gear 172.
82 and a needle repair ring 183, it is attached to the main shaft 168 so as to be relatively rotatable. Also,
The sleeve 182 includes an oil pump drive sprocket 1B4 that rotates together with the primary driven gear 6.
are fitted. This oil pump drive sprocket 184 is connected by a chain 185 to an oil pump 186, which will be described later.

Next, the clutch mechanism 174 will be explained. As shown in FIG. A clutch center 188 that rotates together with the main shaft 168, and friction plates 187a on the clutch outer 187 side and the clutch center 18B side...1
88a... and these two friction plates 187a... 18
8a, etc., which press the clutch plate 189 into pressure contact with each other.

The clutch pressure plate 189 is rotatably provided around the axis of the main shaft 2 via a pole bearing 191 with respect to an end piece 190 that supports one end of the operating rod 175, and is rotated to the left by a clutch spring 192. At this time, the friction plates 187a, . . . , 188a, . When the operating rod 175 moves to the right, the clutch pressure plate 189 integrally moves in the same direction, and at this time the clutch mechanism 174 is disengaged.

The operation rod 175 is moved in the axial direction by a clutch release 193 provided on the left side of the crankcase 69. This clutch release 193 is composed of a release shaft 194 that engages with an end of an operating rod 175 and a rack and pinion, a release lever 195 fixed to the upper end of this release shaft 194, a return spring 196, etc. is connected to a clutch wire (as shown) operated by a flange lever 197 attached to the handle par 30 of the left handle 4.

When the clutch wire is operated (pulled) by the clutch lever 197, the release lever 195
At the same time as the release shaft 194 is rotated via the clutch mechanism 174, the operating rod 175 moves to the right and the clutch mechanism 174 is disengaged.

Change mechanism 162 that switches and controls the transmission 161
To explain, as shown in FIG. 6, this change mechanism 162 includes a change spindle 198 rotatably supported by a transmission case 163, and several cam grooves 19 on the outer periphery.
9a is formed and rotatably supported by the transmission case 163 via a pole bearing 200.
A shift drum center 201 is arranged at one end of the shift drum 199 and rotates integrally with the lift drum 199, and has shift bins 201a radially formed at the end thereof and engagement recesses 201b formed locally, and a change spindle 1.
A retaining part 202a fixed to the right end of 98 and provided at the tip
The shift plate 202 engages with the shift pin 201a of the shift drum center 201, and the shift plate 202 is fixed to the transmission case 163 and its tip is connected to the shift drum center 201
a stopper plate 203 that engages with the engagement recess 201b of 1 to regulate the rotation angle of the shift drum 199; and a shift fork shaft 7) 20 supported by the transmission case 163.
4, the shift 7 oak shaft 204 is slidably mounted in the axial direction of the shaft 204, and one end is attached to the cam groove 199a of the shift drum 199, and the other end is attached to the main shaft 186 and each transmission gear 170a of the countershaft 71-169. 17
171a to 171f as appropriate.

Change spindle 198, shift drum 199, and shift fork shaft 204 are arranged parallel to main shaft 168 and counter shaft 169 of transmission 161, respectively.

And the transmission case 16 of the change spindle 198
When the change spindle 198 is rotated by a certain angle by a change pedal (not shown) to which the protruding end l from 3 is spline-fitted, this rotation is caused by the shift plate 202
, shift drum 19 via shift drum center 201
9, and as each shift fork 205 is appropriately slid by the rotation of this shift drum 199, each transmission gear 170a-17Of and each transmission gear 171a
The engagement with ~171f can be changed as appropriate.

Note that the transmission case 163 includes the clutch mechanism 17
A clutch cover 206 and a driven sprocket cover 207 covering the driven sprocket 180 at the end of the countershaft 169 and the clutch cover 206 are respectively fixed.

Now, the engine 8, transmission 161, etc. having the above configuration are as follows.
The lubricating oil supply device 15 provided at the bottom of the engine 8
8, each sliding portion thereof is lubricated.

As shown in FIG. 4, this lubricating oil supply device 158 includes the oil pan 93, which is integrally fixed to the lower part of the lower case 69b of the crankcase 69 and stores a lubricating oil therein, and the oil pan 93, which is immersed in the lubricating oil. The oil strainer 208 installed in the crankcase 69 and the pipe 20 installed in the crankcase 69
The oil pump 186 is connected to the oil strainer 208 through the oil filter 186, the oil filter 159 is fixed to the front part of the crankcase 69 and is connected to the oil pump 186 through the oil passage 210, and The oil relief valve 211 is provided in the lubricating oil tank and is immersed in the lubricating oil.

As described above, the oil pump 186 is connected to the oil pump drive sprocket 184 of the main shaft 168 via the chain 185, and is operated by the rotation of the engine 8 to supply lubricating oil to the oil strainer 208.
It is sucked up from the pipe 209 and sent to the oil filter 159 via the oil passage 210, and then sent to the oil passage 212.
to the transmission 161 (main shaft 168, countershaft 169, clutch mechanism 174, etc.), and also to the engine 8 (crankshaft 101, piston 97
, each camshaft 7) 114, 115, etc.).

Then, the lubricating oil that has finished its lubricating action returns to the oil pan 93 and is stored there, and is again circulated through the above-mentioned path. Note that some of the lubricating oil supplied to the engine 8 is
As shown in FIG. 4, the oil is supplied into the piston holder 127 of the cam chain tensioner 125 through an oil passage 214 and is used as hydraulic oil for the cam chain tensioner 125 that constantly presses the piston 128.

Further, when the lubricating oil passes through the oil filter 159, it is cooled by the cooling water passing through the water pipe 157.

In this circulation of lubricating oil, for example, as the engine 8 (crankshaft 101) rotates at high speed,
When the oil pressure of the lubricating oil to be pumped increases and reaches a certain level of oil pressure, the oil relief valve 211 is activated to return an appropriate amount of the lubricating oil passing through the oil passage 210 into the oil pan 93, and the oil pressure is no longer increased. is adjusted so that it does not rise.

The oil relief valve 211 is normally operated by being biased by a spring 216 into a bottomed cylindrical outer cylinder 215 that communicates with the oil passage 210 and has a lubricating oil outlet 215a formed in its body. houses an inner cylinder 217 that closes the discharge port 215a, and when the lubricating oil passing through the oil passage 210 reaches a certain oil pressure as described above, the lubricating oil causes the inner cylinder 217 to release the spring 216.
By moving against this, the discharge port 215a opens and the lubricating oil is discharged into the oil pan 31 from this discharge port 215a.

Now, between the joint surfaces 218 and 219 of the oil pan 93 and the lower case 69b, there are
An oil pan gasket 220 according to this embodiment is interposed to seal the space between the oil pans 9 and 9.

This oil pan gasket 220 is formed from a thin metal plate, and as shown in FIG.
8. Outer periphery in contact with 219 (outside of the two-dot chain line) 220
Each joint surface 21B, 21 is integrally formed with this outer peripheral part on the inside of a.
A protruding portion 220b is formed which protrudes an appropriate length toward the inside of the oil pan 93 along the line 9, and is wider than each of the joint surfaces 21B and 219. Projection 220
The width of b is approximately uniform, and an aperture 220c is formed in the central portion on the inside thereof, and lubricating oil returns into the oil pan 93 through this aperture 220c.

The oil pan gasket 220 is fitted to the joint surface 219 of the lower case 69b, and then the joint surface 218 of the oil pan 93 is matched, and the oil pan gasket 220 and the oil pan 93 are fixed to the lower case 69b by bolts 221 screwed into the lower case 69b. joint surface 218.219
It seals the space between. Note that the outer peripheral portion 220a includes:
A plurality of through holes 222 for the bolts 221 are formed at equal intervals, and a hole 223 through which the oil relief valve valve 211 of the protrusion 220b passes is formed.

According to the oil pan gasket 220, the engine 8
Even when the oil pan 9 is operated at medium to high speeds, the lubricating oil after lubrication passes through the opening 220c to the oil pan 9 reliably and promptly.
3, a constant amount of lubricating oil is always stored in the oil pan 93. In addition, even if the lubricating oil stored in the oil pan 93 rises along the inner wall of the oil pan 93 as the internal pressure of the crankcase 69 increases when the engine 8 is operated at medium to high speeds, the lubricating oil does not reach the oil pan. It hits the protrusion 220b of the gasket 220 and is prevented from rising any further, so that no oil leakage occurs. Further, air bubbles contained in the lubricating oil returning into the oil pan 93 hit the protrusion 220b, and the size thereof becomes smaller or is crushed and disappears. As a result, stable supply of lubricating oil to the engine 8, transmission 161, etc. is achieved.

8 and 9 show another embodiment of the present invention, in which the oil pan gasket 224 has a round opening 224C of an appropriate size instead of the opening 220c in the oil pan gasket 220. These openings 224c are formed in large numbers and are arranged diagonally inside the protrusion 224b continuous with the outer peripheral part 224a, with a remaining part 224d remaining between them.

Note that this pipe 20 is located at a location corresponding to the pipe 209 connecting the oil strainer 208 and the oil pan 93.
A hole 225 through which the hole 9 is passed is formed. In addition, the outer peripheral portion 22
Similar to the oil pan gasket 220, a bolt through hole 226 is formed in 4a, and a hole 227 through which the oil relief valve 211 passes is formed in the protrusion 224b.

Such an oil pan gasket 224 can also provide the same effect as the oil pan gasket 220 of the previous embodiment, and in addition, the oil level of the lubricating oil in the oil pan 93 can be raised or lowered due to changes in the posture of the vehicle body. Even if the opening 22
The remaining portion 224d between 4c suppresses its vertical movement, and lubricating oil is stably supplied. Mat-, oil pan 93
If air is present in the lubricant that returns to the remaining part 22
4d, the air is released and then falls into the oil pan 93 through the opening 224C, thereby reducing the amount of air contained in the lubricating oil in the oil pan 93.

Note that FIG. 10 shows a modification of the other embodiment described above, in which downward protrusions 224e are provided integrally with the oil pan 93 on the circumference of each 224c on the lower surface of the oil pan 93. According to this, the protrusions 224e act as ribs to increase the strength of the oil pan gasket 224, and when the engine 8 is in operation, the lubricating oil splashes splashed up from inside the oil pan 93 are prevented from forming on the protrusions 224e.
24e, making it difficult to return above the oil pan gasket 224.

[Effects of the Invention] As explained above, according to the engine oil pan gasket of the present invention, the protrusion protrudes inward of the oil pan by an appropriate length along the joint surfaces of the crankcase and the oil pan. The oil pan is characterized by having a hole all around the entire circumference of the oil pan, and an opening in the center inside the protruding part, which ensures lubrication even when the engine is operated at medium and high speeds. The finished lubricating oil reliably and quickly returns to the oil pan through the opening, and even if the lubricating oil in the oil pan rises along the wall of the oil pan as the internal pressure of the crankcase increases, it will not protrude. , which prevents it from rising any further. As a result, a constant amount of lubricating oil is always stored in the oil pan, and a stable supply of lubricating oil to the engine, transmission, etc. is achieved.

Furthermore, when the lubricating oil returns into the oil pan containing air bubbles during engine operation, when it hits the protrusion, the air bubbles collapse or become smaller and return into the oil pan. Lubricating oil with less impact is supplied.

[Brief explanation of the drawing]

Fig. 1 is an overall side view of a motorcycle to which an embodiment of the present invention is applied, Fig. 2 is a front view thereof, Fig. 3 is a partially sectional left side view of the engine, and Fig. 4 is a partially sectional sectional view of the engine. A right side view, FIG. 5 is a longitudinal sectional view of the engine, FIG. 6 is a partially sectional plan view of the change mechanism, FIG. 7 is a view taken along the line ■-■ in FIG. 4,
FIG. 8 is a plan view of another embodiment, and FIG. 9 is II- of FIG.
A view taken along the line II and FIG. 10 are cross-sectional views showing a modification of another embodiment. 1... Motorcycle, 8... Engine,
69... Crank case, 93... Oil pan, 218... Oil pan joint surface, 2
19...Crankcase joint surface, 220.2
24...Oil pan gasket, 220b, 2
24b... Protrusion, 220c, 224c...
...opening area.

Claims (1)

[Claims] An oil pan gasket that is interposed between joint surfaces of a crankcase and an oil pan constituting an engine to seal the joint surfaces, the oil pan gasket comprising: An oil pan for an engine, characterized in that the oil pan is provided with a protrusion that protrudes inward by an appropriate length over the entire circumference of the oil pan, and that an opening is formed in a central portion inside the protrusion. gasket.