JPH0343627A - Balancer device of internal combustion engine - Google Patents

Abstract

PURPOSE:To reduce the cost in a speed change gear provided with a main shaft interlocking with a crank shaft, and with a lay shaft interlocking with the main shaft through a change gear, by using the lay shaft as a balancer shaft that supports a balance weight, and by rotating it by the main shaft through a gear line. CONSTITUTION:In an engine provided with a speed change gear 3 that has a main shaft 5 interlocking with a crank shaft 1 through a clutch device 4, as well as a lay shaft 7 interlocking with the main shaft 5 through a gear line 6, and with a balancer device 8, a primary balancer 9 of the balancer 8 is provided on an end of a hollow shaft 27 outwardly fitted to the main shaft 5 in an integrated form. On a periphey of the end of the hollow shaft 27, a primary moved gear 20 integrated with a clutch outer 15 is fixed. A secondary balancer 10 of the balancer device 8 is provided on an end of a hollow shaft 29 outwardly fitted to the lay shaft 7 at a counter position to the hollow shaft 27, which is rotated interlocking with the primary balancer 9, through a driving means 30 formed out of a driving gear 31 integrated with the hollow shaft 27, and of a moved gear 32 integrated with the secondary balancer 10.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a balancer device for an internal combustion engine.

(Prior Art) A balancer device for an internal combustion engine reduces vibrations during operation of the internal combustion engine by rotating a primary balancer weight in the opposite direction at the same speed as the crankshaft. Furthermore, in some cases, the secondary balancer weight is rotated at twice the speed of the crankshaft to reduce secondary vibrations.

This type of balancer device has, for example, the following balancer weight:
As disclosed in the publication, a balancer weight is attached to a balancer shaft provided parallel to the crankshaft so as to be rotatable therewith, and the balancer weight is attached via a pair of gears provided on the crankshaft and the balancer shaft. It is known that the balancer weight is rotated by interlocking the balancer shaft with the crankshaft.

However, in a balancer device having such a configuration, a dedicated balancer shaft is provided, which impedes the miniaturization and weight reduction of internal combustion engines, and there is no relationship with other components of the internal combustion engine, such as in motorcycles. When installing a new starting device such as a kick starter in an engine, it is necessary to separately set up a means of transmitting power from the starting device to the crankshaft. This may require significant changes, which hinders the reduction of manufacturing costs.

(Problems to be Solved) The present invention eliminates such inconveniences, reduces the number of component parts, makes it smaller and lighter in weight, and is effective for other components such as the starting device of an internal combustion engine. The purpose of this invention is to provide a balancer device that can be utilized effectively.

(Means for Solving the Problems) In order to achieve the above object, the balancer device for an internal combustion engine of the present invention has a main shaft interlocked with the crankshaft via a clutch device, and a subshaft interlocked with the main shaft via a transmission gear. and a balancer device having a balancer weight that is rotated via a drive means in conjunction with the crankshaft, wherein the balancer weight is rotatable around the countershaft. supported, the drive means comprising:
a drive gear integrally provided with the clutch outer of the clutch device and rotatable around the main shaft; and a drive gear integrally provided with the balancer weight rotatably around the sub-shaft and meshed with the drive gear. and a driven gear.

The balancer weight is a secondary balancer weight for reducing secondary vibrations during operation of the internal combustion engine.

Furthermore, the secondary balancer weight and the driven gear are integrally provided on a hollow shaft supported concentrically with and rotatably around the subshaft.

Further, the driven gear may be meshed with a starting gear of a starting device for the internal combustion engine.

(Operation) According to this means, the subshaft of the transmission is used as a balancer shaft that supports the balancer weight. When the internal combustion engine is in operation, the drive gear is rotated around the main shaft via a clutch outer of the clutch device in conjunction with the rotation of the crankshaft, and the balancer weight is further engaged with the drive gear. The clutch outer and the drive gear are rotated about the subshaft through the driven gear in a direction opposite to that of the clutch outer and the drive gear. Further, the main shaft of the transmission rotates in the same direction as the clutch outer and the drive gear when the clutch device is connected, and the subshaft interlocked with the main shaft via the transmission gear train rotates in the opposite direction to the main shaft. Therefore, the subshaft and the balancer weight rotate in the same direction.

When the balancer weight is the secondary balancer weight, the gear ratio of the driving gear and the driven gear is set at a gear ratio such that the rotational speed of the driven gear is twice the speed of the crankshaft. This causes the secondary balancer weight to rotate around the secondary shaft at twice the speed of the crankshaft.

Furthermore, when the secondary balancer weight and the driven gear are integrally provided on the hollow shaft, the secondary balancer weight and the driven gear are rotated about the secondary shaft via the hollow shaft. Supported freely.

Further, when the driven gear is engaged with the starting gear of the starting device of the internal combustion engine, the driving force of the starting device is transmitted to the crankshaft via the starting gear, the driven gear, the driving gear, and the clutch device in this order. This starts the internal combustion engine.

(Example) An example of a balancer device for an internal combustion engine according to the present invention will be described with reference to FIG. FIG. 1 is an explanatory cross-sectional view of a main part of a single-cylinder four-stroke engine for a motorcycle equipped with the balancer device.

In FIG. 1, l is a crankshaft connected to an engine piston (not shown) via a connecting rod 2;
3 is a main shaft 5 that is interlocked with the crankshaft 1 via a clutch device 4; and a subshaft 7 that is interlocked with the main shaft 5 via a transmission gear train 6.
8 is a primary balancer weight 9 (
A balancer device 11 is a kick starter that is an engine starting device. The crankshaft 1 and the main shaft 5 and sub-shaft 7 of the transmission 3 are arranged parallel to each other.

The main shaft 5 of the transmission 3 is rotatably supported via bearings 13 and 14 by a crankcase 12 that rotatably supports the crankshaft 1, and a clutch device is attached to the end protruding from inside the crankcase 12. 4 is installed.

This clutch device 4 includes a clutch outer 15 which is fitted around the end of the main shaft 5 concentrically therewith, and a clutch inch which is housed inside the clutch outer 15 and is rotatably attached to the main shaft 5 concentrically with the main shaft 5. 16, which are concentrically and rotatably connected to the main shaft 5 through a plurality of clutch plates 18 which are overlapped and pressed together between the 8 clutch inner 16 and the lid plate 17. . On the end surface of the clutch outer 15 on the crankcase 12 side, a primary driven gear is meshed with a primary drive gear 19 rotatably attached to the end of the crankshaft 1 at a gear ratio of 1:1. 20 is fixed concentrically with the main shaft 5, thereby transmitting rotation of the crankshaft 1 due to engine operation to the clutch outer 15 via the primary drive gear 19 and the primary driven gear 20, and further connected to the clutch outer 15. The state is transmitted to the main shaft 5 of the transmission 3 via the clutch inner 16.

Note that the clutch device 4 includes the above-mentioned lifter brake in the main shaft 5.
Bushing rod 2 slidably inserted toward 17
1, and the lifter plate 17 is slid in the direction away from the clutch inner 16 by a clutch drive device (not shown) to release the mutually pressed state of the clutch plates 18. At this time, the clutch outer 15 and the clutch inner 16 are in a disconnected state, and the rotation of the crankshaft l is not transmitted to the clutch inner 16 and the main shaft 5.

The countershaft 7 of the transmission 3 is rotatably supported by the crankcase 12 via bearings 22.23, and the main shaft 5 is transmitted from the crankshaft l via the clutch device 4, similar to known transmissions. The rotation of the transmission gear 6 is transmitted while being changed in several stages depending on the combination of meshing of the transmission gear train 6. A driving sprocket 24 is rotatably attached to the end of the countershaft 7 that protrudes from inside the crankcase 12, and the driving sprocket 24 is connected to a wheel (not shown) via a chain 25. , whereby the driving force of the engine is outputted from the subshaft 6 to the wheels.

The primary balancer 9 of the balancer device 8 is integrated with an end portion inside the crankcase 12 of a hollow shaft 27 that is concentrically and rotatably inserted into the main shaft 5 via a needle bearing 26 between the main shaft 5 and the bearing 14. The hollow shaft 27
It is rotatably supported around the main shaft 5 via. The primary driven gear 20 is rotatably fitted into the outer circumferential surface of the end of the hollow shaft 27 protruding outside the crankcase 12 by spline connection, whereby the primary balancer 9 and the hollow shaft 27 are connected together. It is configured to rotate around the main shaft 5 together with the clutch outer 15.

On the other hand, the secondary balancer 10 of the balancer device 8 has a hollow shaft 29 which is concentrically and rotatably fitted onto the secondary shaft 7 via a needle bearing 28 at a position facing the hollow shaft 27 in the crankcase 12. It is integrally provided at one end of the shaft 29 and is rotatably supported around the subshaft 7 via the hollow shaft 29 .

A driving means 30 for rotating the secondary balancer 10 is configured to rotate the primary balancer 9 of the hollow shaft 27 and the crankcase 12.
It consists of a driving gear 31 that is integrally and concentrically provided in the middle part, and a driven gear 32 that is integrally and concentrically provided at the end of the hollow shaft 29 on the opposite side of the secondary balancer 10.
and a driven gear 32 are meshed with each other at a gear ratio of 2:1.

The kick starter 11 includes a starter spindle 34 that is rotatably supported by a crankcase 12 and a clutch cover 33 attached to the crankcase 12, and a starter spindle 34 that is rotatably supported by a crankcase 12 and a clutch cover 33 attached to the crankcase 12. and a rotatably supported starting gear 35,
The starting gear 35 is the driven gear 32 of the hollow shaft 29.
A ratchet portion 35a is formed on the end surface of the clutch cover 33 side. Further, at a position between the starting gear 35 and the clutch cover 33, a driving ratchet is integrally rotatably and slidably fitted to the starter spindle 34 and is biased in a direction away from the ratchet portion 35a. 36 are provided. Further, a return spring 37 is attached to the end of the starter spindle 34 inside the crankcase 12, so that the starter spindle 34 is returned to its original position after the starter spindle 34 has rotated a predetermined amount.

Next, the operation of the balancer device 8 and kick starter 11, which are the essential parts of the present invention, in such a gutter bottom engine will be explained.

First, in the balancer device 8, when the crankshaft 1 rotates due to engine operation, the hollow shaft 27, the secondary balancer 9, and the drive gear 31 are connected to the main shaft integrally with the clutch outer 15 and the primary driven gear 20 of the clutch device 4. The hollow shaft 29 and the secondary balancer IO are rotated around the hollow shaft 29 and the driven gear 32 meshed with the drive gear 31.
rotates around the secondary shaft 7. At this time, since the gear ratio of the primary drive gear 19 and the primary driven gear 20 is l:1, the -order balancer 9 rotates in the opposite direction at the same speed as the crankshaft l, thereby reducing the primary vibration of the engine. is reduced. A drive gear 31 of the drive means 30
Since the gear ratio of the driven gear 32 is 2:1, the secondary balancer 10 rotates in the same direction at twice the speed of the crankshaft 1, thereby reducing secondary vibrations of the engine.

At this time, when the clutch device 4 is in the connected state, the main shaft 5 rotates together with the clutch device 4, so the -order balancer 9 and the hollow shaft 27 rotate at the same speed and in the same direction as the main shaft 5. Further, since the subshaft 7 rotates in the opposite direction to the main shaft 5 via the transmission gear train 6, the secondary balancer 0 and the hollow shaft 29
rotates in the same direction as the subshaft 7.

Therefore, the main shaft 5 and sub-shaft 7 of the transmission 3 are used as balancer shafts of the primary balancer 9 and secondary balancer 10, respectively, and the number of parts of the balancer device 8 is reduced, making it lighter and smaller. .

Further, as described above, the hollow shaft 2 provided with the primary balancer 9
7 and the hollow shaft 29 provided with the secondary balancer 10 rotate in the same direction as the main shaft 5 and the sub-shaft 7, respectively, so the needle bearings rotatably support these on the main shaft 5 and the sub-shaft 7, respectively. 26.28 of the capacity can be reduced.

On the other hand, in the kick starter 11, the starter spindle 3
4 is connected to the kick pedal outside the clutch cover 33 (
by operating the drive ratchet 36 (not shown).
slides and is engaged with the ratchet portion 35a of the starting gear 35, and the starter spindle 34 is rotated together with the drive ratchet 36, whereby the starting gear 35 is rotated and the hollow shaft 29 is rotated. be done. At this time, the hollow shaft 29 rotates in the same direction as the crankshaft 1 as described above, thereby starting the engine.

Therefore, in this engine, the driving means 30 of the balancer device 8 and the like are effectively utilized as means for transmitting the driving force from the starting gear 35 of the kick starter 11 to the crankshaft 1.
There is no need to separately provide the transmission means.

Next, a second example of the present invention will be explained with reference to FIG. FIG. 2 is an explanatory cross-sectional view of the main parts of an engine equipped with a starting device using a starter motor.

In this engine, the gutter bottom of the crankshaft 11, transmission 3, balancer device 8, etc. is the same as that of the engine shown in FIG.
is connected to the starter motor 42 via the starting gear 39 of the starting device 38, the one-way clutch 40, and the driven gear 41 in this order.
It is connected to the drive gear 42a. starting gear 39
is rotatably supported around a starter spindle 43 which is rotatably supported by the crankcase 12 and the clutch cover 33 and meshed with the driven gear 32, and the driven gear 41 is integrated with the end of the starter spindle 43. The drive gear 42a of the starter motor 42 is rotatably mounted on the
is engaged with. The starter spindle 43 is connected between the starting gear 39 and the driven gear 41.
They are connected via a one-way clutch 40 provided concentrically with the two, and can freely rotate together when the clutch 40 is connected.

Therefore, in this engine, the rotational driving force of the starter motor 42 is transmitted from the driving gear 42a to the driven gear 41, the one-way clutch 40, the starting gear 39, and the balancer device 8.
The driving means 30 of the balancer device 8 is transmitted to the crankshaft 1 through the driving means 30 at around 1, and the driving means 30 of the balancer device 8 is effectively utilized for starting the engine, similar to the engine shown in the first figure. Particularly in this case, the rotational driving force transmitted from the starter motor 42 to the crankshaft 1 is transmitted to the drive means 30.
Since the speed is reduced between the driven gear 32 and the driving gear 31,
The reduction ratio can be reduced between the driving gear 42a and the driven gear 41 of the starter motor 42, and an idle gear may be interposed between the two gears 42a and 41 as in the conventional starting device of this type, or By increasing the diameter of the driven gear 41, it is not necessary to obtain a large reduction ratio, and the driven gear 41 can be directly meshed with the drive gear 42a, and the driven gear 41 can be made small in diameter.

Next, a third example of the present invention will be explained with reference to FIG. FIG. 3 is an explanatory sectional view of the main parts of an engine using a recoil starter as a starting device.

This engine has the same internal configuration as the engine shown in the first diagram, and has a clutch cover 3 of the starter spindle 34.
3. A recoil starter 44 is attached to the outwardly protruding end of the kick pedal as shown in FIG. It was designed so that

Therefore, in this engine as well, the driving means 30 of the balancer device 8 is effectively utilized to start the engine, similar to the engine shown in the first drawing, and the same effects as in the engine shown in the first drawing are achieved.

In this embodiment, a kick starter, a starting device using a starter motor, and a recoil starter have been described as starting devices, but even if other starting devices are used, the starting gear thereof can be meshed with the driven gear 32 of the driving means 30. Of course, by doing so, the drive means 30 can be effectively utilized for starting the engine.

Finally, a reference example of the gutter bottom of an engine equipped with a kick starter will be described in accordance with FIG. I'll keep it. FIG. 4 is an explanatory sectional view of the main parts of the engine.

In the engine of this reference example, similarly to the embodiment of the present invention,
- A secondary balancer a is rotatably supported via a hollow shaft e on a main shaft d of a transmission C which is interlocked with a crankshaft (not shown) via a clutch device, and is also supported via a clutch device via the hollow shaft e. It is connected to the clutch outer f. A small-diameter driven gear g integrally formed on the outer circumferential surface of the hollow shaft e is connected to a large-diameter drive gear j integrally provided on a hollow shaft i rotatably supported on a subshaft of the transmission C. A small-diameter idle gear k formed integrally with the outer peripheral surface of the hollow shaft i is further meshed with a large-diameter starting gear m of the kick starter 2.

In such an engine, the rotation of the starter spindle n of the kick starter l is accelerated between the starting gear m and the idle gear and transmitted to the hollow shaft i, and is further transmitted from the hollow shaft i to the driving gear j and the driven gear 8. The speed is increased and transmitted to the crankshaft via the hollow shaft e and the clutch device.

Therefore, in this engine, the rotation of the starter spindle n is greatly accelerated and transmitted to the crankshaft, so that the engine can be easily started by the kick starter i.

(Effects) As is clear from the above description, according to the balancer device for an internal combustion engine of the present invention, by using the countershaft of the transmission as the balancer shaft and supporting the balancer weight on the countershaft,
The number of parts of the balancer device is reduced, and the weight and size of the balancer device can be reduced. The balancer weight is interlocked with the crankshaft by meshing a driven gear that can rotate integrally with the balancer weight around the subshaft and a drive gear that can rotate integrally with the clutch outer of the clutch device. As a result, the balancer weight is rotated in the same direction as the subshaft, and the capacity of the bearing for rotatably supporting the balancer weight on the subshaft can be reduced.

At this time, when the balancer weight is a secondary balancer weight, the balancer weight is rotated around the subshaft at twice the speed of the crankshaft, so it is rotatably supported on the subshaft. By reducing the capacity of the bearing, it is possible to significantly reduce the cost of the bearing.

Furthermore, by integrally providing the secondary balancer weight and driven gear on the hollow shaft, the balancer weight and driven gear are supported by the subshaft via the hollow shaft with a needle bearing or the like in a small and simple configuration. be able to.

Furthermore, by meshing the starting gear of the starter with the driven gear of the drive means that interlocks the balancer elite with the crankshaft, the drive means can be used as a means for transmitting driving force from the starter to the crankshaft. , the components of the balancer device can be effectively utilized. In particular, if the starter uses a starter motor and the balancer weight is a secondary balancer weight, the driven gear rotates at twice the speed of the crankshaft, so the rotation of the starter Since the driving force is reduced in speed and transmitted to the crankshaft via the driving means, it is possible to reduce the reduction ratio of the rotational driving force of the starter motor in the starting device by gears, etc., and to achieve miniaturization of the configuration. I can do it.

[Brief explanation of drawings]

FIG. 1 is an explanatory sectional view of the essential parts of an engine equipped with an example of a balancer device and a kick starter according to the present invention, and FIG. 2 is an explanatory sectional view of the essential parts of an engine equipped with a starting device using a starter motor. FIG. 3 is an explanatory sectional view of a main part of an engine equipped with a starting device using a beam coil starter, and FIG. 4 is an explanatory sectional view of a main part of a reference example of an engine equipped with a kick starter. 1... Crankshaft 4... Clutch device 6... Speed change gear train 8... Balancer device 11, 38.44... Starting device 30... Drive means 32... Driven gear 3...・Transmission device 5...Main shaft 7...Subshaft 10...Balancer weight 15...Clutch outer 31...Drive gears 35, 39...Starting gear

Claims (1)

[Claims] 1. A transmission device consisting of a main shaft interlocked with the crankshaft via a clutch device and a subshaft interlocked with the main shaft via a transmission gear, and a transmission device interlocked with the crankshaft via a drive means. In the internal combustion engine, the balancer weight is rotatably supported around the counter shaft, and the driving means is integrated with a clutch outer of the clutch device. a drive gear rotatably provided around the main shaft; and a driven gear rotatably provided integrally with the balancer weight and meshed with the drive gear. Characteristics of internal combustion engine balancer devices. 2. The balancer device for an internal combustion engine according to claim 1, wherein the balancer weight is a secondary balancer weight for reducing secondary vibrations during operation of the internal combustion engine. 3. The internal combustion engine according to claim 2, wherein the secondary balancer weight and the driven gear are integrally provided on a hollow shaft supported concentrically with and rotatably around the subshaft. Engine balancer device. 4. The balancer device for an internal combustion engine according to claim 1, wherein the driven gear is meshed with a starting gear of a starting device for the internal combustion engine.