JPH10259733A - Transmission case integral type engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To layout each shaft of a transmission compactly so as to be suitable for arrangement as an engine for an automobile, to facilitate assembly of each shaft of the transmission to a case, and to improve rigidity of the case. SOLUTION: In this transmission case integral type engine 1, an integrally formed case at the lower part of a cylinder block is formed as a case body 14 wherein the ends on one side of shafts contained in the case form a release surface, the release surface of the case body 14 is closed by a cover member 19, the shafts 31, 32, and 33 of the transmission are reassembled to an intermediate plate member 30 on the ends on one side of the respective shafts, and the intermediate plate member 30 is fixed at a plurality of bosses raised on the inner surface of the case body 14. This constitution securely houses and fixes the engine in the case body 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission case-integrated engine in which a transmission case is integrated with a crankcase below a cylinder block.

[0002]

2. Description of the Related Art Generally, in an engine for an automobile,
For the crankshaft that extends along the longitudinal direction of the body,
A transmission input shaft (main shaft) is arranged in series, and a separate transmission case is connected to the rear of a crankcase having an oil pan connected to a lower portion, while a multi-cylinder 4 for a motorcycle is provided. In a cycle engine, generally, an input shaft (main shaft) of a transmission is arranged in parallel with a crankshaft extending along the width direction of the vehicle body, and a transmission case is mounted on a crankcase below a cylinder block. And an oil pan are continuously integrated.

[0003] In such a transmission case-integrated engine, a case portion of a lower portion of a cylinder block in which a crankcase, a transmission case, and an oil pan are integrated is usually formed so as to be divided into upper and lower portions, and a crankshaft and an oil pan are formed. The main shaft and the counter shaft of the transmission are arranged in parallel along the dividing surface such that they are respectively supported by bearings at the dividing surface of the case portion via bearings.

[0004]

By the way, regarding the conventional transmission case integrated engine as described above,
Since the case part is divided into upper and lower parts and each axis is arranged along the division surface, when applied to an automobile engine in which a reverse axis is arranged with respect to the input shaft and the output shaft of the transmission, Is difficult to assemble each axis of the transmission, and when installing the engine on the vehicle body so that the direction of each axis is the front and rear direction of the vehicle body, the engine is placed in the width direction (direction orthogonal to each axis). It becomes long and bulky, which is inconvenient in terms of space.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described disadvantages of the conventional transmission case-integrated engine. Specifically, in the transmission case-integrated engine, each transmission shaft is provided. It is an object of the present invention to make it possible to freely arrange the components and to easily assemble the components so as not to cause any inconvenience when used as an automobile engine.

[0006]

According to the present invention, a transmission case is integrated with a crankcase below a cylinder block to solve the above-mentioned problems. In the transmission case integrated type engine, an integrated case below the cylinder block is formed as a case body having one end side of each shaft housed therein as an open surface, and the open surface of the case body is While being closed by the cover member, each shaft of the transmission is pre-assembled to the intermediate plate member at one end side of each shaft, and the intermediate plate member is mounted on a plurality of mounting bosses erected from the inner surface of the case body. By being fixed, it is housed and fixed in the case main body.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a transmission case integrated engine according to the present invention will be described below with reference to the drawings.

FIG. 1 to FIG. 6 show an air-cooled engine for an automobile according to an embodiment of a transmission case integrated engine of the present invention. FIG. 1 shows a front side of the engine.
Fig. 2 shows the longitudinal direction of the engine (the direction of the axis of the crankshaft).
FIG. 3 shows a cross section of each part along the width direction of the engine (a direction orthogonal to the crankshaft), and FIG. 4 shows a cross section of the balancer and the valve driving cam shaft. FIG. 5 shows the right side (left side as viewed) of the engine in which a part of the engine casing is cut, and FIG.
Is the left side of the engine (right side as viewed) with a portion of the engine casing cut along each axis of the transmission
FIG. 6 shows the state of attachment of the intermediate plate member to the transmission case (case body).

The transmission case-integrated engine 1 of this embodiment is an in-line two-cylinder air-cooled four-stroke engine for an automobile, in which two cylinders are arranged in series along the longitudinal direction of the vehicle body. As shown in FIG. 2, a cylinder head 3 covered with a head cover 2 is provided with one intake port 4 and one exhaust port 5 for each cylinder, and an opening is provided in the ceiling of the combustion chamber of each cylinder. Intake port 4
And the respective combustion chamber-side openings of the exhaust port 5 are arranged so as to be arranged along the cylinder arrangement direction so that the flow of the air-fuel mixture becomes a turn flow (counter flow).

As shown in FIG. 3, each of the intake valve 6 and the exhaust valve 7 provided for opening and closing the combustion chamber-side opening of the intake port 4 and the exhaust port 5 in each cylinder, as shown in FIG. The push rod 8 is vertically opened and closed via the rocker arm 9 in accordance with the vertical movement of the long push rod 8 extending from the side.

Openings of the cylinder head 3 outside the intake port 4 and the exhaust port 5 (the side opposite to the combustion chamber) are formed on one side (left side) of the cylinder head 3 as shown in FIG. As shown in FIG. 3, an intake pipe 10 and an exhaust pipe 11 are connected to outer openings of the intake port 4 and the exhaust port 5, respectively.

In the present embodiment, the cylinder block connected to the lower end face of the cylinder head 3 as described above is
As shown in FIG. 3, a portion of the crankcase which extends downward from a cylinder portion 13 in which cylinders of the respective cylinders are arranged in the front-rear direction defines a crankcase defining a crankcase 15 and a transmission chamber 16. Body 1 in which a transmission case to be integrated and an oil pan 17 are integrated
4 is formed.

The case body 14 of the cylinder block is integrally formed below the cylinder portion 13 with its front side being open.
Is closed in a closed state by a front cover 19 fixed to the case body 14 with bolts.

In the interior of the case body 14, a portion of the crank chamber 15 located below the cylinder portion 13 is provided.
As shown in FIG. 2, a crankshaft 20 is supported by a rear wall portion of the case body 14 and a front cover 19 via a bearing, and a portion of the crank chamber 15 is partially shielded from the oil pan 17. As a result, a baffle plate 18 is integrally formed from the inner surface of the case main body 14.

The crankshaft 20 has the same phase of the crank arm in each cylinder, and a flywheel 21 is attached to the rear end of the crankshaft 20 that protrudes outward from the rear side wall of the case body 14. The flywheel 21 is covered with a carver 22 fixed to the case body 14 by bolts.

An oil pump 23 is formed at the front end of the crankshaft 20 on the front side of the front cover 19, and supplies the lubricating oil discharged from the oil pump 23 to the large end of the connecting rod of each cylinder. Oil passage 2 for
4 is formed on the crankshaft 20 itself.

An oil passage 25 for feeding oil from the oil pan 17 to the oil pump 23 is formed in the front cover 19 corresponding to the oil pump 23 formed on the front side of the front cover 19. An oil filter 26 provided in the middle of the oil passage 25 is integrally fixed to the front side of the front cover 19.

As described above, the oil pump 23 and the oil filter 26 are installed on the front cover 19, and the oil passage 24 for supplying lubricating oil from the oil pump 23 to each cylinder is formed in the crankshaft 20 itself. In the engine 1 of the embodiment, a long oil passage for supplying lubricating oil from the oil pump 23 on the front of the engine to each cylinder is formed on the side surface of the cylinder block (the case main body 14). No need to install.

Therefore, the cylinder portion 13 and the case body 1
The oil passage is easily machined by machining the small and easy-to-handle front cover 19 and crankshaft 20 without machining the large and cumbersome cylinder block with the integrated 4. The oil filter 26 can be formed while the front cover 19
In the vertically mounted engine 1 as in the present embodiment, the oil filter 26 can be easily attached and detached on the front side.

On the other hand, in the engine 1 as described above,
Right side of the crankcase 15 in the case body 14 (that is,
3 and 4, a cam shaft 35 for driving the intake / exhaust valves 6 and 7 is provided on the left side.
Also, a balancer 36 for canceling the vibration of the crankshaft 20 is provided between the rear end wall of the case body 14 and the front cover 19.
In a state of being pivotally supported by the gears, they are installed so as to interlock with the rotation of the crankshaft 20 via gears.

The cam shaft 35 for driving the valve is
The push rods 8 are moved up and down in accordance with the rotation of the cam nose formed above. The up and down movement of each push rod 8 causes the intake and exhaust valves 6 and 7 to move through the rocker arm 9. Each is driven to open and close.

With respect to the balancer 36, if the crankshaft 20 has the same phase of the crank arm in each cylinder, the crankshaft 20 cancels the reciprocating inertial force of the piston.
Since the lateral vibration generated by the centrifugal force of the balance weight provided on itself is large, in order to cancel such lateral vibration of the crankshaft 20, its rotation axis is parallel to the crankshaft 20. And crankshaft 2
It is located laterally away from 0.

In the present embodiment, in contrast to the balancer 36 that is disposed laterally away from the crankshaft 20 as described above, the tip (front end) of the rotating shaft of the balancer 36 that projects outward from the front cover 19. Further, a cooling fan 37 for forcibly cooling the engine 1 is integrally fixed thereto.

And, from the crankshaft 20 to the side (right side)
A shroud (air duct) 38 for guiding the cooling air from the cooling fan 37 is provided along the side surface (right side surface) of the engine 1 with respect to the cooling fan 37 disposed at a distance from the engine 1.

As described above, the engine 1 of the present embodiment in which the cooling fan 37 is fixed to the tip (front end) of the rotating shaft of the balancer 36 is different from the engine in which the cooling fan is provided at the tip of the crankshaft. As a result, the flow of the cooling air can be made smooth to improve the cooling efficiency, and the rotating shaft of the existing balancer 36 is also used as the rotating shaft of the cooling fan 37. There is no increase in cost due to the provision of the shaft and the interlocking mechanism.

As shown in FIG. 5, in the engine 1 of the present embodiment as described above, a portion of the transmission chamber 16 located on the left side (that is, on the right side) of the crank chamber 15 in the case body 14 is provided as shown in FIG. , Main shaft 31,
The counter shaft 32 and the reverse shaft 33 are
And a rear wall portion of the case main body 14 which is formed separately from the main shaft 3. A main shaft 3 is provided on the front side of the intermediate plate member 30.
A clutch mechanism 34 is attached to the front end of the first clutch 1.

As shown in FIGS. 3 and 6, the intermediate plate member 30 formed separately from the case main body 14 is mounted on a plurality of mounting bosses 14a integrally formed from the case main body 14. On the other hand, the shafts 31 to 33 of the transmission are detachably and integrally fixed by bolts, and
The front surface of the transmission chamber 16 in which is stored and fixed is covered by a front cover 19 in a sealed state.

As described above, with respect to the case body 14 whose front face is opened,
According to the transmission case-integrated engine 1 of the present embodiment in which the transmission shafts 31 to 33 are housed and fixed via the intermediate plate member 30, there is a degree of freedom in the arrangement of the transmission shafts 31 to 33. Each axis 3
1 to 33 can be laid out compactly, so that even if the crankcase, the transmission case, and the oil pan are integrated as the case body 14, the entire engine 1 does not become so long in its width direction, And a compact device suitable for mounting on a vehicle.

Moreover, the transmission shafts 31 to 31
33 is pre-assembled with the intermediate plate member 30 in advance and is housed in the case body 14 from the open front side and assembled, so that the transmission shafts 31 to 33 can be easily assembled to the case body 14. Can be.

Further, since the intermediate plate member 30 is integrally fixed by a plurality of mounting bosses 14a formed integrally from the case body 14, the mounting bosses 14a are integrally fixed.
By forming a, the rigidity of the case body 14 itself is improved, and the rigidity of the case body 14 is further improved by integrally fixing the intermediate plate member 30 to the mounting boss 14a with bolts.

In this embodiment, the intake pipe 10 and the exhaust pipe 1 of each cylinder are provided above the transmission chamber 16 outside the case body 14 as shown in FIG.
1 is connected to one side surface (left side surface) of the cylinder head 3, and therefore, it is necessary to heat a riser with exhaust gas for atomizing fuel in an engine with a carburetor, so that an intake pipe 10 is provided. Even if it is a large manifold in which the exhaust pipe 11 is integrated with the exhaust pipe 11, the whole engine can be packaged compactly without such a part protruding.

[0032]

According to the transmission case-integrated engine of the present invention as described above, since there is a degree of freedom in the arrangement of each shaft of the transmission, the arrangement of each shaft can be compactly laid out, and The entire case for housing the shaft can be made compact and suitable for installation as an automobile engine,
The transmission shafts can be easily assembled to the case, and the rigidity of the case can be improved.

[Brief description of the drawings]

FIG. 1 is a front view showing an air-cooled two-cylinder four-cycle engine for a vehicle according to an embodiment of a transmission case-integrated engine of the present invention.

FIG. 2 is an explanatory cross-sectional side view of a cross section along the front-rear direction (axial direction of a crankshaft) of the engine shown in FIG.

FIG. 3 is an explanatory sectional front view showing a section of each part along a width direction (a direction orthogonal to a crankshaft) of the engine shown in FIG. 1;

FIG. 4 is a right side view, partly in section, of the engine shown in FIG. 1 with a part of a casing cut so that a balancer and a cam shaft for driving a valve can be seen;

5 is a partially sectional left side view of the engine shown in FIG. 1, with a part of the casing cut along each axis of the transmission.

FIG. 6 is an explanatory cross-sectional view showing a mounting state of an intermediate plate member to a case main body of the engine shown in FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Engine 14 Case body 14a Mounting boss (of case body) 19 Cover member (front cover) 30 Intermediate plate member 31 Main shaft (of transmission) 32 Counter shaft (of transmission) 33 Reverse shaft (of transmission)

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI F16H 57/02 501 F16H 57/02 501A 501F (72) Inventor Shigeru Iguchi 2500 Shinkai, Iwata City, Shizuoka Prefecture Yamaha Motor Co., Ltd.

Claims (1)

[Claims] 1. A transmission case-integrated engine in which a transmission case is integrated with a crankcase under a cylinder block, wherein the integrated case under the cylinder block is connected to each of the shafts housed therein. Formed as a case body with one end side open,
The open surface of the case body is closed by a cover member, and each shaft of the transmission is pre-assembled to the intermediate plate member at one end of each shaft,
A transmission case-integrated engine, wherein the intermediate plate member is fixed to a plurality of mounting bosses erected from the inner surface of the case body to be housed and fixed in the case body.