JP3445263B2 - Water-cooled parallel 4-cylinder engine - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-cooled parallel four-cylinder engine used for motorcycles.

[0002]

2. Description of the Related Art A parallel four-cylinder engine for a motorcycle is disclosed in, for example, Japanese Patent Laid-Open No.
The one disclosed in Japanese Patent Publication No. 0-73060 is known. This parallel four-cylinder engine drives a camshaft from one end of the crankshaft via a cam chain. The parallel four-cylinder engine having such a structure is very advantageous in making the cylinder and the cylinder head compact in the axial direction of the crankshaft.

However, in the above-mentioned conventional technique, no consideration has been given to the downsizing of the engine in the power transmission system from the crankshaft and the auxiliary equipment drive system. In particular, in order to increase the output of the engine, total consideration including the water cooling system and the lubrication system is required.

The present invention has been made in view of the above circumstances, and provides a water-cooled parallel four-cylinder engine that can achieve a total compactness and high output including a water cooling system and a circulation system. It is an object.

[0005]

In order to achieve the above object, a water-cooled parallel 4-cylinder engine according to the invention of claim 1 is
A water-cooled parallel four-cylinder engine for a motorcycle, in which a crankshaft is arranged in the vehicle width direction at the front of the crankcase, wherein a cam chain is wound around one end of the crankshaft and an pulsar for ignition is provided outside the camchain. The rotor is attached, the pulse generator is arranged radially outward of the pulsar rotor, the AC generator and the one-way clutch are arranged adjacent to each other on the other end side of the crankshaft, and the starter motor mounted on the rear surface of the cylinder and the one-way are arranged. A drive gear for driving the clutch is formed in a crank web portion on the one end side of the crank shaft by connecting with the clutch, and the clutch includes a driven gear driven by the drive gear, and the driven gear is coaxially provided. With a drive gear that drives an oil pump that is rotatably arranged Embody, together with placing the water pump to the side surface of the crankcase, it is characterized in that connected to the oil cooler of the oil filter by body provided on the front crankcase.

A water-cooled parallel four-cylinder engine according to a second aspect of the present invention is the water-cooled parallel four-cylinder engine according to the first aspect, wherein the clutch includes a release shaft that engages and disengages the clutch outward in the vehicle width direction. , The release lever that drives the release shaft is
It is characterized by being provided at the lower end of .

A water-cooled parallel four-cylinder engine according to a third aspect of the present invention is the water-cooled parallel four-cylinder engine according to the first aspect, wherein the water pump supplies cooling water from the front side of the substantially central portion of the four cylinders. It is characterized in that it is introduced to the radiator from the cylinder via a thermostat provided on the opposite side of the cylinder from the water pump.

According to the parallel four-cylinder engine of the present invention,
It is possible to arrange a cam chain, a pulsar rotor for ignition and the like on one end side of the crankshaft, and integrate drive systems for auxiliary machines such as a clutch, a water pump and an oil pump on the one end side. As a result, the drive system can be accessed from one end side of the crankshaft, and the maintainability can be improved. Further, it becomes possible to arrange the AC generator and the starter system arranged on the other end side of the crankshaft in good balance.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment applied to a parallel four-cylinder engine mounted on a motorcycle will be described below as an embodiment of the present invention with reference to the accompanying drawings. During the explanation,
The directions such as front and rear and left and right are with respect to the vehicle body. FIG. 1 is a side view of the motorcycle 1, and FIGS. 2 and 3 are front views.

This motorcycle 1 has a body frame 2 and
A pair of left and right front forks 3 rotatably supported on the front end of the body frame 2, and these front forks 3
A steering handlebar 4 attached to the upper end of the vehicle, a front wheel 5 rotatably supported by the front fork 3, a rear fork 6 swingably supported by the vehicle body frame 2,
A rear wheel 7 rotatably supported at the rear end of the rear fork 6, a water-cooled engine 8 according to the present invention supported by the vehicle body frame 2, and a radiator 9 also supported by the vehicle body frame 2, A fuel tank 10 arranged on the upper part of the vehicle body frame 2, a seat 11 arranged behind the fuel tank 10, on which a driver and an occupant sit, and steps 12 and 13 for a driver and an occupant, A retractable stand 14 that supports the vehicle body in an upright state during parking is provided, and almost the entire vehicle body is covered by a cowling 15 shown in FIG.

The vehicle body frame 2 has a head pipe 16 at the front end, and a front engine hanger 17a and a rear engine hanger 17b which are divided into left and right from the head pipe 16 and extend rearward and obliquely downward and extend forward and backward.
A pair of left and right main frames 17 each having a hollow cross section integrally molded with each other, the head pipe 16, and the front engine hanger 1
A gusset pipe 18 that connects 7a and a pair of left and right upper rails 19a and 19b that are connected to the rear end of the main frame 17 and extend rearward and obliquely upward and have their rear ends welded to each other. The seat rail 19 is provided. A battery D is accommodated below the seat 11 in the front space between the left and right seat rails 19.

In the step 12 for the driver, the rear engine hanger 17b is mounted via the step bracket 20.
The occupant step 13 is fixed to the lower seat rail 19b via a step bracket 21, and the stand 14 is attached to the lower engine hanger 17b. The lower pipe 2 is attached to the lower end of the head pipe 16 of the body frame 2.
A steering stem (not shown) integrally provided with 2 is inserted rotatably around an axis, and a top bridge 23 is fixed to an upper end portion of the steering stem protruding from the head pipe 16.

The front fork 3 has a bottom case 24 and a cushion (not shown) on the bottom case 24.
The inner tube 25 is slidably inserted through the inner tube 25, and the inner tube 25 is inserted and fixed to the left and right ends of the top bridge 23 and the lower bridge 22, respectively. As a result, the front fork 3 is rotatable integrally with the steering stem via the top bridge 23 and the lower bridge 22.

The handles 4 are a pair of left and right sides, and inner ends thereof are fitted and fixed to upper end portions of the front forks 3 which project from the top bridge 23. The front wheel 5 is formed by mounting a tire 27 on the outer periphery of a wheel 26 having an axle 26a provided at its axis.
Both ends of the axle 26a are supported by the bottom end of the bottom case 24 of each front fork 3. The left and right bottom cases 24 are provided with front fenders 28 that cover the front wheels 5 from above.

On both the left and right sides of the wheel 26 of the front wheel 5, a rotor 30 constituting a front disc brake device 29 is provided.
Is fixed coaxially and integrally with the wheel 26. The front disc brake device 29 has the rotor 30.
And the rotor 3 is fixed to the rear side of the bottom case 24 of each front fork 3 via a stay 31 and is in an operating state.
It is composed of a brake caliper 32 that brakes its rotation with frictional force across 0, and a brake lever 33 that is attached to the right handle 4 and that operates the brake caliper 32.

The rear fork 6 has a base 3 at the front end thereof.
4 has a pair of left and right fork portions 35 extending rearward, and the base portion 34 is pivotally supported by a pivot 36 provided between the rear engine hangers 17b of the main frame 17 to pivot the pivot 36. The fork 35 is vertically swingable. The fork 3
5, a triangular bulge 35a is attached to the upper part of
A rear fender 37 that covers the front upper portion of the rear wheel 7 is integrally attached to the bulging portion 35a.

The rear wheel 7 has a diameter slightly larger than that of the front wheel 5, and like the front wheel 5, a tire 39 is mounted on the outer circumference of a wheel 38 having an axle 38a at the center thereof. Both ends of the rear fork are supported by the rear end of the fork portion 35 of the rear fork 6, so that they swing together with the rear fork 6.

The rear cushion unit 40 damps the swing of the rear wheel 7 received from the road surface. The rear cushion unit 40 is composed of a damper 41a, a spring 41b, and the like, and has an upper end pinned to a cross member (not shown) fixed between the left and right main frames 17, and a lower end of the cushion body 41. Both ends of a first link 42 having one end pin-coupled to it, and a cross member (not shown) provided between the other end of the first link 42 and the lower ends of the left and right rear engine hangers 17b. The second link 43 is pin-connected to each other.

The rear wheel 7 is also equipped with a rear disc brake device including a rotor and a brake caliper similar to the front disc brake device 29 of the front wheel 5, but the description thereof is omitted here. A sprocket 44 is coaxially fixed to the wheel 38 of the rear wheel 7 on the left side of the wheel 38, and a drive chain 45 described later is wound around the drive sprocket 44.

As shown in FIGS. 5 to 7, the engine 8 includes a cylinder block 49 composed of a cylinder block body 46, a cylinder head 47 and a cylinder head cover 48, and a crank arranged under the cylinder block 49. A parallel four-cylinder four-cycle engine including a case 50 and four cylinders (cylinders) 51 arranged in parallel in the left-right direction inside a cylinder block 49.
The front side of the cylinder block 49 of the engine 8 is a front side engine hanger 17a of the main frame 17 with the cylinder block 49 slightly tilted forward.
The rear side to the main frame 17 via the stay 52,
The rear part of the crankcase 50 is the rear engine hanger 1.
It is supported by the vehicle body frame 2 by being bolted to 7b.

At the rear of the cylinder block 49 of the engine 8, the cylinder block 4 is provided by the intake action of the engine 8.
The carburetor 53 for supplying the air-fuel mixture is connected to the inside of
Further, an air cleaner 54 is connected to the carburetor 53. The air cleaner 54 is arranged in a recess 10a formed in the lower surface of the front side of the fuel tank 10. An intake pipe 55 bent downward is connected to a front portion (upstream side) of the air cleaner 54, and an intake port 53a of a carburetor 53 is inserted into a rear portion thereof.

An exhaust pipe 56 is connected to the front of the cylinder block 49 for each cylinder 51. As shown in FIG. 2, first exhaust pipes 56a, 2 from the left side
Exhaust pipe 56b, exhaust pipe 56c, exhaust pipe 56d
These four exhaust pipes 56 extending downward extend from the connection end portion to the cylinder block 49, are aligned below the engine 8, and are further bent to crank the crankcase 5.
It extends rearward along the lower surface of the crankcase 0 and is gathered in one collecting pipe 57 on the lower rear side of the crankcase 50. The collecting pipe 57 is routed to the right side of the rear wheel 7 while rising diagonally rearward to the right, and a cylindrical silencer 58 extending diagonally upward is attached to the tip of the collecting pipe 57. The engine 8 will be described in detail later.

The radiator 9 is a horizontally long rectangular cross-flow type in which a cooling water inflow side tank (not shown) is connected to the right side of the core and an outflow side tank 9a is connected to the left side of the core. It is arranged in front of the engine 8 in this state and is supported by the front engine hanger 17 a and the gusset pipe 18. Immediately behind this radiator 9 is a radiator fan 9 for cooling the radiator 9.
A is equipped. Also, in front of the radiator 9,
An alarm device 59 is provided. The alarm 59 is attached to the front engine hanger 17a via stays 60 and 61.

As shown in FIGS. 1 to 4, the cowling 15 includes a front cowl 62 that covers the front portion of the vehicle body and has an upper end surface along the main frame 17, and a portion below the fuel tank 10 and the seat 11. It consists of a rear cowl 63 that covers the rear part of a vehicle body, and a front cowl 62.
Is divided into an upper cowl 64, a middle cowl 65 and an under cowl 66.

Upper cowl 64 of front cowl 62
Is formed in a streamlined shape from the front to the rear of the head pipe 16 and covers both sides of the upper part of the front fork 3 and both sides of the radiator 9 and the cylinder block 49 of the engine 8, and both sides of the front part are covered. A notch 64a that avoids interference with the handle 4 is formed, and a substantially U-shaped notch 64b when viewed from the front is formed at the upper end of the front part. The notch 64b has a notch 64a. A transparent screen 67 is integrally provided so as to extend while curving to almost the upper side and cover the upper side of the front fork 3. A front end portion of the upper cowl 64 is supported by a cowl stay (not shown), and side portions thereof are bolted to the main frame 17 and the front engine hanger 17a.

Further, as shown in FIG. 2 and the like, air inlets 68 for introducing traveling wind to the radiator 9 are formed on the left and right of the front portion of the upper cowl 64, and the center between these air inlets 68 is formed. A headlight 69 is disposed in the headlight 69, and an air inlet 70 is also formed above the headlight 69. In addition, inside the upper cowl 64, a meter unit 71 to which a speedometer, an engine tachometer, etc. are attached is arranged. This meter unit 71 is
It is attached to the head pipe 16 via a stay 72. Further, turn indicators 73 are attached below the left and right air inlets 68 of the upper cowl 64, respectively.

Middle cowl 65 of front cowl 62
Is formed in a shape that matches the notch 64c at the rear of the upper cowl 64, and is located at the rear side of the engine 8 and has an upper cowl 64 and an under cowl 66.
It is bolted to. An exhaust port 65a for discharging the air introduced into the cowling 15 to the outside is formed at the front end of the middle cowl 65.

Under cowl 66 of front cowl 62
Has a U-shaped cross section and covers both sides of the crankcase 50 of the engine 8 and the exhaust pipe 56 continuously from the lower end of the upper cowl 64, and is bolted to the main frame 17. An air introduction port 66 for introducing traveling wind into the under cowl 66 is provided at a lower front portion of the under cowl 66.
a is formed.

The rear cowl 63 is formed so as to cover the side of the seat rail 19 composed of the upper rail 19a and the lower rail 19b, two left and right, and a tail portion 63a covering the rear portion of the seat 11 at the rear portion thereof. Is integrally provided and is attached to each of the rails 19a and 19b by a fitting means such as a hook. A rear fender 74 that covers the upper rear portion of the rear wheel 7 is attached to the rear end of the rear cowl 63. In addition, two exhaust ports 63 for exhausting the air inside the rear cowl 63 to the outside are provided at the front portion thereof.
b and 63c are formed.

Next, the engine 8 will be described in detail with reference to FIGS. The engine 8 includes the cylinder block body 46 and the cylinder head 47 as described above.
Also, a cylinder block 49 including a cylinder head cover 48 and a crankcase 50 are provided. The crankcase 50 is joined to the upper case 50a and the lower case 50b so as to be separable, and the upper case 50a and the cylinder block body 46 are integrally cast-molded. Has been done. An oil pan 75 is joined under the lower case 50b. A crankshaft 81 is arranged in the vehicle width direction at the front of the crankcase 50, and a transmission 131 and a clutch mechanism 144 are provided at the rear of the crankcase 50.
Are arranged.

As shown in FIG. 7, the cylinder block 49
The four cylinders 51 are arranged in parallel with each other, and a piston 77 is slidably fitted in these cylinders 51 via a casting sleeve 76. These pistons 7
The chain sprocket 7 is rotatably supported in the crankcase 50 via a connecting rod 78 and has one end (in this case, the right end: the end on the side where the clutch mechanism 144 is present).
9 is connected to a crankshaft 81 in which an oil groove 80a for supplying lubricating oil is formed on the peripheral surface of the journal portion 80, and rotation of the crankshaft 81 causes the cylinder 5 to rotate.
It is adapted to slide up and down in the inside of 1. As shown in FIG. 5, the connecting rod 78 is formed with an oil hole 82 for sending the lubricating oil flowing through the oil groove 80 a to the lower surface of the piston 77. The oil hole 82 extends linearly from the upper surface of the large end portion 78a of the connecting rod 78 in a direction slightly biased to the piston 77 side from the center of the large end portion 78a.

As shown in FIG. 5, the cylinder head 47 is provided with a combustion chamber 83 formed by the cylinder head 47 and each piston 77 reaching the top dead center, and each combustion chamber 83. Against spark plug 8
4 is screwed in, and further, an intake passage 85 and an exhaust passage 86 are formed which connect each combustion chamber 83 and the outside.

As shown in FIG. 9, the intake passage 85 is divided into a combustion chamber 83 in one cylinder 51, a main intake passage 85A that is open to the outside, and a branch portion 85B.
The two branch passages 85a and 85b are formed by branching into two, and each of these branch passages 85a and 85b communicates with the combustion chamber 83, and these two openings form intake ports 87a and 87b, respectively. .

Further, two exhaust ports, which are openings of the exhaust passage 86 to the combustion chamber 83, are formed for one combustion chamber 83. That is, the exhaust passage 86 is formed of two branch passages 86a and 86b communicating with the combustion chamber 83, and a main exhaust passage 86A is formed through a collecting portion 86b. The branch passages 86a and 86b are opened to the combustion chamber 83. Are exhaust ports 88a and 88b, respectively.

The cylinder head 47 has a structure shown in FIGS.
Etc., the intake valves 89a, 87b, the intake valves 89a for opening and closing the exhaust ports 88a, 88b,
89b and exhaust valves 90a and 90b are provided, respectively. As shown in FIG. 8, each intake valve 89a, 89b has a valve stem 91 having an umbrella-shaped valve body 91a that actually opens and closes each intake port 87a, 87b, and biases this valve stem 91 upward. A valve spring 9 that causes the valve body 91a to close the intake ports 87a and 87b.
2 and a tubular valve lifter 93 mounted on the upper end of the valve stem 91, and the like, and the valve stem 91 is slidably inserted in a valve guide 94 fitted in the cylinder head 47.

The exhaust valves 90a and 90b are similar to the intake valves 89a and 89b, and are composed of a valve stem 95 having a valve body 95a, a valve spring 96, a valve lifter 97, a valve guide 98 and the like.
The intake valves 89a, 89 are provided on the cylinder head 47.
b, an intake side camshaft 99 and an exhaust side camshaft 100 for operating the exhaust valves 90a and 90b are arranged in parallel with the crankshaft 81.

The camshafts 99 and 100 are hollow, and the fastening bolts 101 are used to tighten the cylinder head 4
It is rotatably supported around a shaft by a bearing cap 102 fixed to 7, and on its peripheral surface, intake side cams 103a, 103b, exhaust side corresponding to intake valves 89a, 89b, exhaust valves 90a, 90b. Cam 104
a and 104b are integrally formed, and a ridge 105 that engages with the bearing cap 102 and restricts axial movement is integrally formed at the right end portion thereof. The hollow portion of each of the camshafts 99 and 100 is a passage for lubricating oil, and the oil hole 220 communicating with this passage is provided.
Is formed from the base surface of each cam 103a, 103b, 104a, 104b to the hollow portion.

Further, cam sprockets 106 and 107 are integrally provided at the right ends of the cam shafts 99 and 100, respectively, and the cam chain 108 is wound around the cam sprockets 106 and 107 and the chain sprocket 79 of the crankshaft 81. The camshafts 99, 100 are rotated with the rotation of the crankshaft 81.
Is designed to rotate.

Then, these camshafts 99, 100
The intake side cams 103a and 103b as the rotor rotates.
And the peripheral surfaces of the exhaust side cams 104a and 104b respectively correspond to the intake valves 89a and 89b and the exhaust valves 90, respectively.
The valve stems 91 and 95 are slidably contacted with the valve lifters 93 and 97 of a and 90b respectively to vertically reciprocate, whereby the intake ports 87a and 87b and the exhaust ports 88a and 88b are opened and closed.

As shown in FIG. 8, a lubricant oil reservoir 47b, which is a recess, is formed around each valve lifter 93, 97 in the cylinder head 47, and the lubricant oil accumulated therein is as described above. And valve lifter 93,
When the 97 moves downward, the valve lifters 93 and 97 and the cams 1
Lubricate sliding with 03a, 103b, 104a, 104b. In FIG. 8, the alternate long and short dash line is a horizontal line in a state where the engine 8 is mounted on the vehicle body (vehicle body frame 2). Further, as shown in FIG. 10, oil holes 4 for returning the lubricating oil to the oil pan 75 are provided at both ends of the cylinder head 47.
7c is formed.

Further, as shown in FIG. 6, on the outer peripheral side of the cam chain 108 between the cam sprocket 106 of the intake side cam shaft 99 and the chain sprocket 79, a cam chain tensioner 109 for suppressing the flapping of the cam chain 108. Are arranged. The cam chain tensioner 109 has one end pin-connected to the cylinder head 47 to be swingable, a tensioning slipper 110 extending along the cam chain 108, and a float 112 inside.
a is housed and fitted in the piston holder 111 arranged in the cylinder block body 46, and the swinging end of the tensioner slipper 110 is constantly driven by hydraulic pressure.
8 and a piston 112 to be pressed.

Similarly, as shown in FIG. 6, a cam chain guide 221 is attached to the cylinder head cover 48 on the outer peripheral side of the cam chain 108 between the cam sprockets 106 and 107.

As shown in FIG. 5, the carburetor 53 is connected to the outside opening of the intake passage 85 (main intake passage 85A) by a cab insulator 113, and the exhaust passage 86 (main exhaust passage). The connection ends of the exhaust pipes 56 are respectively connected to the openings on the outer side of 86A).

The cylinder head cover 48 joined to the cylinder head 47 communicates with the crank case 50 through the cylinder head cover 48 and the cam chain chamber 108a in which the cam chain 108 is arranged. A breather chamber 114 for separating oil contained in the blow-by gas generated therein is provided. The blow-by gas from which oil has been separated in the breather chamber 114 is released to the atmosphere from the air guide pipe 115 connected to the breather chamber 114.

Further, as shown in FIGS. 6 and 7, the crankshaft 8 is provided at the right end of the crankshaft 81.
1 and a generator cover 117 fixed to cover the crankcase 50.
Further, an ignition timing detection mechanism 119 including a pulse generator 118 supported at a radially outer position of the pulsar rotor 116 is provided.

At the left end of the crankshaft 81,
A rotor 120 that rotates integrally with the crankshaft 81,
An AC generator 123 including a stator 122 supported by an AC generator cover 121 fixed to the crankcase 50 is provided. The AC generator cover 121 projects slightly outward from a circular opening 66b (see FIG. 4) formed in the under cowl 66 of the front cowl 62. The upper space of the AC generator cover communicates with a lubricating oil passage 46b formed in the cylinder block body 46, and the lubricating oil passage 46b extends above the guide rib 121a formed on the inner surface of the AC generator cover 121. AC through
Lubricating oil is supplied to the sliding portion of the generator cover 123.

Further, this AC generator cover 12
A starter motor driven sprocket 125 is mounted on the crankshaft 81 inside the No. 3 via a needle bearing 124. The starter motor driven sprocket 125 is connected to the inner circumference of a ring 120a fixed to the rotor 120 via a one-way clutch 126 and is located on the left side of the upper case 50a of the crankcase 50. The drive shaft 128 of 127 is connected via gears 129 and 130. The ring 120a has a plurality of oil holes 120b which serve as passages for lubricating oil (see FIG. 7).
So only one can be seen).

Next, the transmission 131 connected to the engine 8 and the change mechanism 132 for switching the transmission 131 will be described.

As shown in FIG. 7, the transmission 131 is provided in a transmission case 133 which is integral with the lower case 50b of the crankcase 50, in parallel with the crankshaft 81, and in the respective needle bearings 134, 135 and ball bearings 136. Hollow main shaft 138 and counter shaft 13 rotatably disposed via 137.
9 (both are spline shafts) and both shafts 13
8, 139 respectively provided with meshing transmission gears 140a to 140f and 141a to 141f, a primary driven gear 143 provided at the right end portion of the main shaft 138 and meshing with the primary drive gear 142 of the crankshaft 81, and also the main shaft. Clutch mechanism 144 provided at the right end of 138
The main shaft 138 includes a clutch mechanism 144 provided at the right end of the main shaft 138, a clutch release 145 that is inserted into the main shaft 138 so as to be movable in the axial direction, and engages and disengages the clutch mechanism 144. Here, the primary drive gear 142 is integrally formed with the outer crank web portion of the outermost cylinder on the clutch mechanism side (the cylinder located on the rightmost side in FIG. 7). Further, one end (right end in FIG. 7) of the main shaft 138 to which the primary driven gear 143 is attached is provided so as to project outward from the crankcase 50.

The main shaft 138 and the counter shaft 139 are both hollow, and the insides thereof serve as lubricating oil supply passages 146 and 147, respectively, and the main shaft 138 and the counter shaft 139 have a supply passage 1 respectively.
46, 147 communicating with the outer peripheral surface, the transmission gear group 140a
-140f and 141a-141b, clutch mechanism 1
Oil holes 148 and 149 for supplying lubricating oil to 44 are formed, respectively.

According to this transmission 131, the power of the engine 8, that is, the rotation of the crankshaft 81 is transmitted to the main shaft 138 via the primary driven gear 143 and the clutch mechanism 144, and subsequently, the respective transmission gear groups 140a to 140f. , 141a to 141f are transmitted to the counter shaft 139, and further transmitted from the driven sprocket 150 fixed to the left end of the counter shaft 139 to the rear wheel 7 via the drive chain 45.

The primary driven gear 143 is
It consists of a main gear 143a and a sub gear 143b,
These gears 143a and 143b are configured to be rotatable relative to each other, but their rotations are restricted by a damper spring 151 so that backlash in meshing with the primary drive gear 142 is suppressed. It is mounted on the main shaft 138 via the shaft so as to be rotatable relative to each other. Further, an oil pump drive sprocket (drive gear) 154 that rotates integrally with the primary driven gear 143 is fitted to the sleeve 152. The oil pump drive sprocket 154 is connected to an oil pump 156 described later by a chain 155. Here, the oil pump drive sprocket 154 is disposed in the space between the crankcase 50 and the primary driven gear 143, and the oil pump drive sprocket 154 and the chain 155 that meshes with the oil pump drive sprocket 154 are the largest of the four cylinders. It is arranged substantially on the same plane as the connecting rod 78 of the outer cylinder (the rightmost cylinder in the example shown in FIG. 7).

Next, the clutch mechanism 144 will be described. As shown in FIG. 7, the clutch mechanism 144 is a clutch outer 157 riveted to the primary driven gear 143, and is housed in the clutch outer 157. The clutch center 158 that rotates integrally with the main shaft 138 and the clutch outer 1
Friction plate 157a on the 57 side and the clutch center 158 side
... 158a ... and these friction plates 157a ... 158
Clutch pressure plate 1 for alternately pressing a ...
It is composed of 59 and the like.

Although the clutch pressure plate 159 rotates integrally with the clutch center 158 by the bolt 160 and is movable in the axial direction of the main shaft 138, it is always urged to the outside (right side in FIG. 7) by the clutch spring 161. In this state, the friction plates 157a ..., 158a ... are pressed against each other to bring the clutch mechanism 144 into the connected state. When the clutch pressure plate 159 is moved to the right by the operation of the clutch release 145, the friction plates 157a to 1
58a separates and the clutch mechanism 144 is disengaged.

The clutch release 145 is fixed to the transmission case 133 and is set on a clutch cover 162 covering the clutch mechanism 144 so as to be rotatable about its axis. The release shaft 163 is rotated to rotate the main shaft. 138 is movable in the axial direction, and the operation rod 16 is connected at its tip to the center of the clutch spring 161 via a ball bearing 164.
5, a release lever 166 fixed to the lower end of the release shaft 163, and a return spring 167 that regulates the rotation of the release shaft 163. The release lever 166 is a clutch lever 168 attached to the left handle 4. A clutch wire (not shown) operated by is connected.

When the clutch wire is operated (pulled) by the clutch lever 168, the release shaft 163 is rotated via the release lever 166, and at the same time, the operation rod 165 is moved to the left and the clutch mechanism 144 is moved. Is cut off.

A change mechanism 132 for switching and controlling the transmission 131 will be described. This change mechanism 132
As shown in FIG. 7, a change spindle 169 rotatably supported by the transmission case 133 and a plurality of cam grooves 170a formed on the outer periphery of the change spindle 169 are rotatably mounted on the transmission case 133 via ball bearings 171. The supported shift drum 170, and the shift drum 170 disposed at one end of the shift drum 170 and integrally rotated with the shift drum 170, have radial shift pins 172a at the ends thereof, and engagement recesses 17 at the periphery thereof.
2b is formed, a shift plate 173 fixed to the right end of the change spindle 169 and an engaging portion 173a provided at the tip of the shift plate 173 engages with the shift pin 172a of the shift drum center 172, and the transmission case 133. The shift drum 17 is fixed and its front end engages with the engaging recess 172b of the shift drum center 172.
A stopper plate 174 for restricting the rotation angle of 0 and a shift fork shaft 175 supported by the transmission case 133 are mounted slidably in the axial direction of the shift fork shaft 175, and one end of the shift drum 17 is slidable.
No. 0 cam groove 170a, the other ends of the transmission gears 140a to 140a of the main shaft 138 and the counter shaft 139.
40f, 141a to 141f, and a plurality of (in this case, three) shift forks 176 that are appropriately engaged. Change spindle 169, shift drum 17
The shift fork shaft 175 and the shift fork shaft 175 are arranged parallel to the main shaft 138 and the counter shaft 139 of the transmission 131, respectively.

The change spindle 16 is spline-fitted to the protruding end of the change spindle 169 from the transmission case 133 by a change pedal (not shown).
When 9 is rotated by a certain angle, this rotation is transmitted to shift drum 170 via shift plate 173 and shift drum center 172, and each shift fork 176 is appropriately slid by the rotation of shift drum 170. The meshing of the transmission gears 140a to 140f with the transmission gears 141a to 141f can be appropriately changed.

A driven sprocket cover 177 that covers the driven sprocket 150 at the end of the counter shaft 139 is fixed to the transmission case 133. The driven sprocket cover 177 has a back plate 177b fixed to the back side of the cover body 177a by ultrasonic welding.

Now, in the engine 8 and the transmission 131 having the above-mentioned structure, each sliding portion is lubricated by the lubricating oil supply device 178 provided in the lower portion of the engine 8. As shown in FIGS. 5, 6 and 11, the lubricating oil supply device 178 is integrally fixed to the lower portion of the lower case 50b of the crankcase 50, and the lubricating oil L is provided therein.
The oil pan 75 for storing the oil, an oil strainer 179 immersed in the lubricating oil L, and an oil strainer 17 mounted in the crankcase 50 via a pipe 180.
9 and the oil filter 182 fixed to the front part of the crankcase 50 and connected to the oil pump 156 via the first oil passage 181.
And an oil relief valve 183 provided in the middle of the first oil passage 181 and immersed in the lubricating oil L.

As described above, the oil pump 156 is connected to the oil pump drive sprocket 154 of the main shaft 138 via the chain 155 and operates by the rotation of the engine 8 to suck up the lubricating oil L from the oil strainer 179. The oil is sent from the pipe 180 to the oil filter 182 through the first oil passage 181. The lubricating oil L that has passed through the oil filter 182 and is filtered has the second oil passage 18 provided in parallel to the first oil passage 181 to the left of the first oil passage 181 in the lower case 50b.
4 is sent to the lower case 50b while passing through a cooling case 185 provided in the front part of the lower case 50b.

As shown in FIGS. 12 to 15, the cooling case 185 is vertically elongated and has a case body 186 interposed between the crank case 50 and the oil filter 182, and the case body. The cover 187 covers the front side of 186 and closes it.

The case body 186 is shown in FIGS.
As shown in FIG. 3, flange portions 188a and 188b to which the oil filter 182 and the lid body 187 are joined are formed on the outer periphery, respectively, and the first oil passage 18 is formed.
1 for communicating the upstream side of the oil filter 182 with the first
Outlet 189, a first inlet 190 communicating with the downstream side of the oil filter 182, and a second outlet 191 connected to the first inlet 190 and rising diagonally upward to the front of the case body 186. A first oil passage pipe 192 that is opened through the second oil passage 184, and a second inflow port 193 that is an opening to the second oil passage 184.
A cooling water port 194 is provided in the upper part, and a connection pipe 19 of a water pipe 195 leading to the inside of the case body 186 is provided in the lower part.
6 is connected. Here, the first oil passage pipe 192 functions as an oil connection passage that connects the cooling case (oil cooler) 185 and the oil filter 182, and the first oil passage pipe 192 is a crankcase. It will be linearly arranged on the front side of 50.

A second oil passage pipe 197 connecting the second outlet 191 and the second inlet 193 is connected to the front side of the case body 186. This oil passage pipe 1
A flange portion 197a integrally formed on the upper and lower sides of 97 is screwed to the case main body 186.

The outer peripheral flange portions 188a, 188
In b, a through hole 19 for fixing to the crankcase 50 is provided.
8 and a screw 199 for fixing the lid 187 are formed at appropriate places. Of these, the lowest through hole 198
Is a drain for draining water.

On the other hand, as shown in FIG. 12, the lid body 187 is a box-like shape having a shape corresponding to the case body 186 and having an appropriate volume inside, and the inner side thereof is the case body 186.
The flange portion 200 formed on the outer periphery is joined to the flange portion 188b of the case main body 186 in a state of facing toward.

The case body 186 is attached to the flange portion 200.
A through hole 198 formed in the flange portion 188b of the cover and a through hole (not shown) corresponding to the screw hole 199 are formed, and a screw (not shown) screwed into the screw hole 199 through the through hole of the lid 187. Joined to the case body 186,
Moreover, the through hole of the lid 187 and the through hole 1 of the case main body 186.
The cooling case 185 is attached to the crankcase 50 by a screw (not shown) that is passed through the screw 98 and screwed into the crankcase 50.
It is fixed to. The cooling case (oil cooler) 1
85 and the oil filter 182 are arranged side by side on the front surface of the crankcase 50, and the tips of the cooling case 185 and the oil filter 182 projecting from each other are the crankcase 50 and the exhaust pipe 56 in front thereof. It is attached so that it is located in the space surrounded by and.

Lubricating oil L passing through this cooling case 185
The route will be described. From the first oil passage 181 into the oil filter 182 via the first outlet 189, and after being filtered by the oil filter 182, the first oil inlet 190 to the first oil passage 189. Going up in the pipe 192,
From the second outlet 191 into the second oil passage 197,
After descending in the second oil passage pipe 197, it enters the second oil passage 184 through the second inflow port 193. As will be described later, circulating cooling water flows into the cooling case 185 from the water pipe 195 to cool the lubricating oil L passing through the second oil passage pipe 197.

The lubricating oil L which has entered the second oil passage 184 through the cooling case 185 is, as shown in FIG. 6 and the like, transmitted from the second oil passage 184 to the transmission 131 (main shaft 138, It is supplied to the counter shaft 139, the clutch mechanism 144, etc.). The lower case 50b of the crankcase 50 is provided with a main gallery 201 communicating with the second oil passage 184. The main gallery 201 extends in the left-right direction, and the lubricating oil L flowing into the main gallery 201 from the second oil passage 184 is supplied to the engine 8 (the crankshaft 81, the piston 7).
7, each camshaft 99, 100, etc.). In FIG. 6, reference numeral 202 indicates the route. Oil pump 1 arranged behind the crankshaft 81
A first oil passage (oil passage) 181 led from 56 to the front of the water-cooled engine through the lower side of the crankshaft 81, and lubricating oil cooled by the cooling case 185 to a crankshaft such as a journal portion. The main gallery 201 that is delivered to each of the receiving parts is provided in the crankcase 50 in a state where the main gallery 201 and the main gallery 201 intersect with each other, and the main gallery 201 is provided above the first oil passage 181 (FIG. 6, see FIG. 11).

Further, as shown in FIG. 6, this route 20
Lubricating oil L passing through 2 is the cam chain tensioner 10
9 is hydraulically operated. That is, in the piston holder 111 and the cylinder block body 46 that form the cam chain tensioner 109,
An oil passage 203 for allowing the lubricating oil L to flow from the path 202 into the piston 112 is formed, and the hydraulic pressure of the lubricating oil L constantly urges the piston 112 toward the tension slipper 110. Then, the lubricating oil L that has finished the lubricating action is returned and stored in the oil pan 75, and is circulated again through the above-described path.

In the circulation of the lubricating oil L, when the hydraulic pressure of the lubricating oil L to be pumped increases and reaches a certain constant hydraulic pressure as the engine 8 (crankshaft 81) rotates at a high speed, for example, as shown in FIG. Also, the oil relief valve 183 shown in FIG. 6 is operated so that an appropriate amount of the lubricating oil L passing through the first oil passage 181 is returned to the oil pan 75 and adjusted so that the hydraulic pressure does not rise any more. Has become.

This oil relief valve 183 has a first
The discharge port 204a of the lubricating oil L is communicated with the oil passage 181 of the inside of the outer cylinder 204 having a bottomed cylindrical shape formed in the body portion thereof, and is normally urged by the spring 205 so that the discharge port 204a is opened. The closed inner cylinder 206 is housed, and when the lubricating oil L passing through the first oil passage 181 reaches a certain hydraulic pressure as described above, the lubricating oil L causes the inner cylinder 206 to resist the spring 205. By moving, the discharge port 204a is opened and the lubricating oil L is discharged into the oil pan 75 from this discharge port 204a.

Next, the cooling system using the radiator 9 will be briefly described with reference to FIGS. 5, 6 and 10. Lower case 50 in crankcase 50
A water pump 207, which is rotated with the rotation of the crankshaft 81, is disposed on the substantially left side in the center of b. The water pump 207 has a radiator hose 208 that communicates with the outflow side tank 9a of the radiator 9.
And a water pipe 195 connected to the cooling case 185 are connected. In addition, the cooling case 185
The inside of the lid body 187 communicates with a water jacket 46 a formed in the cylinder block body 46 via a cooling water port 194 formed in the case body 186.

Further, the cylinder head 47 is formed with a water jacket 47a which is continuous with the water jacket 46a of the cylinder block body 46. As shown in FIG. 10, the water jacket 47a is at the rear right side of the cylinder head 47. Cooling water passage 2
It is connected to 09. A thermostat 209a is provided in the cooling water passage 209, and when the cooling water passing therethrough reaches a certain temperature or higher, the radiator fan 9A operates.

A radiator hose (both not shown) communicating with the inflow side tank of the radiator 9 is connected to the tip of the cooling water passage 209. The above is the cooling water circulation path, and the cooling water cooled by the radiator 9 is cooled by the operation of the water pump 207 to pass through the radiator 9 → the radiator hose 208 → the water pump 207 and the water pipe 195 and the lid of the cooling water case 185. After entering the inside of 187 and cooling the lubricating oil L as described above, the engine 8 is cooled by passing through the water jackets 46a and 47a, and then returning from the cooling water passage 209 to the radiator 9. That is, FIG. 3, FIG. 12, FIG.
As shown in FIG. 15, the water pump 207 has four
Cooling water is introduced into the cylinders from the front of the center of the two cylinders.
It has become so.

Next, the secondary air supply device 210 for exhaust gas according to the present invention will be described below with reference to FIGS. 8, 9, and 15 to 26. The secondary air supply device 210 is arranged in front of the engine 8 and is connected to a downstream side of the air cleaner 54 via a secondary air supply pipe (not shown), and an exhaust passage 86 in each cylinder 51. Of the secondary air supply passage 212 formed in either one of the two branch passages 86a and 86b on the upstream side of the collecting portion 86B, and the secondary air supply passage 212 and the downstream side of the reed valve 211. And a connecting pipe 213 for connecting to each other.

Each of the secondary air supply passages 212 is connected to the right branch passage 86b in the first cylinder 51a and the third cylinder 51c, and to the left branch passage 86a in the second cylinder 51b and the fourth cylinder 51d. From the front surface of the cylinder head 47 to the inside thereof, the openings on the outer side of these secondary air supply passages 212 are
The connection pipe 213 is connected.

Inside the reed valve 211, each connecting pipe 2
A passage communicating with 13 is formed, and a valve body of the reed valve (none of which is shown) is provided for each of these passages. Then, when the engine 8 is in the operating state and the combustion chamber 8
The exhaust gas generated in No. 3 passes through the exhaust passage 86, so that the inside of the secondary air supply passage 212 and the connecting pipe 213
A negative pressure is created inside each valve body, and air (hereinafter referred to as secondary air) is supplied from the air cleaner 54 through the secondary air supply pipe, the reed valve 211, and the connection pipe 213 to supply each secondary air. Each branch passage 86a (or 86b) from the passage 212
It will be supplied inside.

By the way, one cylinder 51 of the exhaust side camshaft 100 of the engine 8 in the present embodiment.
Of the exhaust valves 90a, 90b corresponding to the branch passage 86a (or branch passage 86b) in which the secondary air supply passage 212 is formed, the other exhaust valve 90b is opened. (Or 90a) is set slightly earlier than when the valve is opened.

That is, those exhaust valves 90a (90
Each exhaust side cam 104a (104b) that opens and closes b) is
A slight angle (for example, 2) with respect to the other exhaust side cam 104b (104a) in the rotation direction of the exhaust side cam shaft 100.
~ 3 degrees) offset. Each exhaust-side cam 104a (104) shown by the symbol (a) in FIG. 19 and FIG.
b) are those. Therefore, the exhaust gas discharged from the combustion chamber 83 flows into the branch passage 86a (86b) on the side where the secondary air supply passage 212 is formed for a moment.
After that, it will flow into the other branch passage 86b (86a).

According to the secondary air supply device 210, as described above, when the engine 8 is in operation and the exhaust gas generated in the combustion chamber 83 passes through the exhaust passage 86, the secondary air is supplied. Inside the supply passage 212 and the connecting pipe 21
The inside of 3 becomes a negative pressure state and each valve element is opened, and the secondary air flows from the air cleaner 54 to the secondary air supply pipe, the reed valve 211,
It is supplied from each secondary air supply passage 212 into each branch passage 86a (86b) via the connection pipe 213.

When the secondary air is supplied to the branch passages 86a (86b) in this way, the branch passages 86a (86b) are supplied.
The exhaust gas flowing into b), that is, the combustion gas remaining in the exhaust gas immediately after being discharged from the combustion chamber 83, reacts with the supplied secondary air and burns (oxidizes).

On the other hand, the unburned gas in the exhaust gas that has flowed into the branch passage 86a (86b) on the side where the secondary air supply tsunami 212 is not formed is discharged when it reaches the collecting portion 86B of the exhaust passage 86. The exhaust gas on this side comes into contact with the secondary air, but the temperature of the exhaust gas on this side increases near the collecting portion 86B due to the combustion of the unburned gas due to the supply of the secondary air in the adjacent branch passage 86a (86b). Therefore, not immediately after being discharged from the combustion chamber 83, not at the collecting portion 86B.
Even if it merges with the secondary air in the above, the unburned gas in the exhaust gas burns sufficiently by reacting with the secondary air, and almost no unburned gas remains. After that, it is discharged to the outside.

That is, the unburned gas remaining in each of the exhaust gases flowing in both branch passages 86a and 86b is effectively burned by the secondary air, and the exhaust gas purification efficiency is greatly improved. By the way, FIG. 23 is a diagram showing the exhaust valve opening / closing timing A at which the exhaust purification efficiency is highest, and FIG. 24 is a diagram showing the exhaust valve opening / closing timing B at which the output is most obtained.
Is a normal intake air with a moderate exhaust purification efficiency and output characteristics.
It is a figure showing the timing C of an exhaust valve. These time shifts are as shown in the graph of FIG. Here, the exhaust valve 90a (may be 90b) on the side where the secondary air supply passage 212 shown in FIG. 22 is formed is the timing A, and another exhaust valve 90b (may be 90a) is the timing A. If each of the exhaust side cams 104a and 104b is set so as to open and close at B, an engine having both optimum exhaust gas purification efficiency and output characteristics can be obtained.

[0085]

According to the water-cooled parallel four-cylinder engine of the present invention, the cam chain and the pulsar rotor for ignition are arranged on one end side of the crankshaft, and the clutch, the water pump, the oil pump, etc. are arranged on the one end side. Since the drive system of the auxiliary machine is integrated, the maintainability can be improved and the balance with the AC generator or the like arranged on the other end side of the crankshaft can be improved. Since the valve train, the rear wheels, and the drive system for the auxiliary machinery are laid out in a well-balanced manner, the load on the crankshaft is also good, and the engine output can be increased.

Further, since the water pump is attached to the side surface of the case, it is easy to connect to the oil cooler provided separately from the oil filter, which is provided on the front surface of the case where the cooling performance is extremely good. It is possible to satisfactorily achieve improvement in the properties and lubricity. Also,
Equipped with a release lever at the lower end of the release shaft
As a result, the center of gravity of the engine can be lowered.

Further, since the cooling water is made to flow from the front side to the rear side of the cylinder, the cooling water can be made to flow smoothly and
The weight balance between the water pump and the thermostat can be made good. As a result, it is possible to provide a cooling system suitable for a high-power engine.

[Brief description of drawings]

FIG. 1 is an overall side view of a motorcycle to which an embodiment of the present invention is applied.

2 is a front view of the motorcycle of FIG. 1. FIG.

FIG. 3 is a front view similar to FIG.

FIG. 4 is a side view of the cowling.

FIG. 5 is a partial cross-sectional left side view of the engine of the present embodiment.

6 is a right side view of the engine of FIG. 5 in a partial cross-section.

7 is a vertical cross-sectional view of the engine of FIG.

FIG. 8 is a side view of a cylinder head.

FIG. 9 is a schematic plan view of a cylinder head.

FIG. 10 is a partial cross-sectional plan view of the engine with the cylinder head cover removed.

FIG. 11 is a partially transparent rear view of the engine.

FIG. 12 is a partial front perspective view of the engine.

FIG. 13 is a front view of a case body in a cooling case.

14 is a rear view of the case body of FIG.

FIG. 15 is a front view of the lower portion of the engine.

FIG. 16 is a front view of a cylinder head.

FIG. 17 is a partial sectional side view of a cylinder head.

FIG. 18 is a side view of the reed valve.

FIG. 19 is a rear view of the exhaust side camshaft.

20 is a side view of the camshaft of FIG.

21 is a side view of the camshaft of FIG. 19 on the opposite side of FIG. 20. FIG.

FIG. 22 is a schematic view of an exhaust passage.

FIG. 23 is a diagram showing an exhaust valve timing when exhaust purification efficiency is the highest.

FIG. 24 is a diagram showing an exhaust valve timing with the highest output characteristic.

FIG. 25 is a diagram showing normal intake / exhaust valve timing.

FIG. 26 is a graph showing a time lag of the exhaust timing of FIGS. 23 to 25.

[Explanation of symbols]

1 ... Motorcycle, 8 ... (Water-cooled 4-cylinder) engine 50 ... Crankcase, 78 ... Connecting rod, 79 ... Chain sprocket, 81 ...
Crankshaft, 108 ... Cam chain,
116 ... Pulser rotor, 118 ... Pulse generator, 131 ... Transmission, 138 ... Main shaft, 142 ... Primary drive gear, 143 ... Primary driven gear, 144 ...
... Clutch mechanism, 154 ... Oil pump drive sprocket (drive gear),

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI F02B 67/00 F02B 67/00 J (58) Fields surveyed (Int.Cl. ⁷ , DB name) F02B 61/02 F02B 61 / 06 F02B 67/00 F01M 1/02 F01M 5/00 F01P 3/02 F01P 3/18

Claims (3)

(57) [Claims] 1. A water-cooled parallel four-cylinder engine for a motorcycle, in which a crankshaft is arranged in the vehicle width direction at the front of the crankcase, wherein a cam chain is wound around one end of the crankshaft and the outside thereof. A pulse generator for ignition was attached to the pulse generator, a pulse generator was arranged radially outside the pulser rotor, an AC generator and a one-way clutch were arranged adjacent to each other on the other end side of the crankshaft, and the pulse generator was mounted on the rear surface of the cylinder. A starter motor and the one-way clutch are connected to each other, a drive gear for driving the clutch is formed in a crank web portion on the one end side of the crankshaft, and the clutch includes a driven gear driven by the drive gear. Drive an oil pump that is coaxially and rotatably arranged. A water-cooled parallel four-cylinder engine that is integrated with a drive gear and has a water pump arranged on the side surface of the crankcase and connected to an oil cooler separate from the oil filter provided on the front surface of the crankcase. 2. The clutch includes a release shaft that connects and disconnects the clutch outward in the vehicle width direction, and a release lever that drives the release shaft is released.
The water-cooled parallel 4-cylinder engine according to claim 1, which is provided at a lower end of the shaft . 3. The water pump introduces cooling water into the cylinders from the front side of the substantially central portion of the four cylinders, and the radiator from the cylinders is passed through a thermostat provided on the back side of the cylinders on the side opposite to the water pumps. The water-cooled parallel four-cylinder engine according to claim 1, which leads to.