JP2653516B2 - Balancer device for internal combustion engine - Google Patents

Description

Description: TECHNICAL 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 primary vibration by rotating a primary balancer weight in the opposite direction at the same speed as a crankshaft in order to reduce vibration during operation of the internal combustion engine. Further, in some cases, the secondary vibration is reduced by rotating the secondary balancer weight at twice the speed of the crankshaft.

Examples of this type of balancer device, particularly a balancer device having a primary balancer weight, are disclosed in, for example, Japanese Patent Application Laid-Open No. 58-3986.
As disclosed in Japanese Unexamined Patent Publication No. 3 (1994), a primary balancer weight is rotatably held on a main shaft of a transmission that is interlocked with a crankshaft via a clutch device, and a driven sprocket integrally formed with the balancer weight is provided. 2. Description of the Related Art There is a known configuration in which a drive sprocket formed on a crankshaft is connected via a chain, thereby rotating the balancer weight in synchronization with the crankshaft.

However, in this balancer device, a dedicated driven sprocket for rotating the balancer weight is provided on the main shaft and the countershaft, and a dedicated driving sprocket is provided on the crankshaft. Therefore, the size and weight of the internal combustion engine are reduced. This was an obstacle to achieving

In addition, for those driven by chains,
A tension applying mechanism (a so-called chain tensioner) is required to prevent problems due to the extension of the chain and the like, which is not preferable in this respect.

In addition, the provision of such dedicated sprockets and chains increases the number of components of the internal combustion engine, increases the number of assembly steps, and reduces the manufacturing cost.

(Problem to be Solved) The present invention solves such a disadvantage, and a balancer device capable of easily reducing the size and weight of an internal combustion engine by using a main shaft or the like of a transmission with a small number of components. The purpose is to provide.

Still another object of the present invention is to provide a balancer device that can reduce a rotational torque acting on a clutch device and a main shaft of an internal combustion engine.

Further, it is an object of the present invention to provide a balancer device capable of easily reducing the weight of the components of the balancer device, effectively utilizing the space, and further improving the assembling workability. With the goal.

Further, it is another object of the present invention to provide a balancer device capable of effectively utilizing the balancer device.

(Means for Solving the Problems) In order to achieve the object, the balancer device for an internal combustion engine of the present invention comprises a main shaft interlocked with a crankshaft via a clutch device and a subshaft interlocked with the main shaft via a transmission gear. And a balancer device having a primary balancer weight that rotates at least in synchronization with the crankshaft, the balancer weight being rotatably supported concentrically about the main shaft. The clutch device is provided integrally with the hollow shaft, and the clutch device is rotatably provided integrally with the hollow shaft, and is connected to the crankshaft so as to rotate at a constant speed and in the opposite direction to the crankshaft. It is characterized by being.

Further, the clutch device is connected to the crankshaft via a primary driven gear rotatably provided integrally with the clutch device and a primary drive gear provided on the crankshaft.

Further, the balancer weight is provided at one end of the hollow shaft, and the clutch device is provided at the other end of the hollow shaft.

Further, the balancer weight is provided integrally with one end of the hollow shaft, the clutch device is fitted and connected to the outer peripheral surface of the other end of the hollow shaft, and the balancer weight of the hollow shaft is provided. One end is accommodated in a case accommodating the transmission, and the other end connecting the clutch device protrudes out of the case.

Further, another balancer weight different from the primary balancer weight is provided, and a driving gear for rotating the other balancer weight is integrally provided on the hollow shaft.

Further, the other balancer weight is a secondary balancer weight.

Further, a driven gear provided integrally with the secondary balancer weight is meshed with the drive gear, and the primary balancer weight is provided rotatably between the secondary balancer weight and the driven gear. It is characterized by.

Further, the secondary balancer weight is rotatably provided on the countershaft.

According to this means, the primary balancer weight is rotatably provided integrally with the clutch device via the hollow shaft integrated with the primary balancer weight, and the clutch device is attached to the crankshaft and the like. The primary balancer weight rotates at the same speed as the crankshaft and in the opposite direction by interlocking the main shaft with the crankshaft via the clutch device. It is moved, and a dedicated driving means for rotating the balancer weight is not required.

Further, at this time, since the main shaft of the transmission rotates together with the clutch device and the primary balancer weight at the same speed as the crankshaft, the clutch device and the main shaft rotate with a relatively small rotating torque.

Further, when the clutch device is connected to the crankshaft via the primary driven gear and the primary drive gear, the rotational force is applied from the crankshaft to the hollow shaft and the primary balancer weight via the heavy clutch device. Is transmitted.

Further, when the balancer weight and the clutch device are provided at both ends of the hollow shaft, the rigidity of the hollow shaft can be easily ensured by balancing the weights of the balancer weight and the clutch device, and the balancer The space between the weight and the clutch device can be utilized.

Further, the balancer weight is provided integrally with one end of the hollow shaft housed in the case, and the clutch device is fitted to the outer peripheral surface of the other end of the hollow shaft protruding out of the case. When connected, the assembling operation of the balancer device is performed by extrapolating a hollow shaft integral with the balancer weight around the main shaft of the transmission accommodated in the case, sealing the case, and then closing the hollow shaft. This is performed by fitting and connecting the clutch device to an end protruding from the inside of the case.

Further, when a driving gear for rotating the other balancer weight is provided integrally with the hollow shaft, the hollow shaft rotated together with the primary balancer weight rotates the other balancer weight. It is used effectively.

Further, when the other balancer weight is a secondary balancer weight, the secondary balancer weight is linked to the crankshaft simply by connecting the hollow shaft and the secondary balancer weight via a pair of gears. And can be rotated.

Further, when the primary balancer weight is rotatably provided between the secondary balancer weight and a driven gear integrally provided with the secondary balancer weight, the primary balancer weight is rotated when the primary balancer weight is rotated. Since it is located in the space between the next balancer weight and the driven gear, the space is effectively used, and the length of the main shaft including both the balancer weight and the both gears in the direction of the main shaft is reduced.

Further, since the secondary balancer weight can be arranged close to the cylinder axis, the couple generated by the secondary balancer weight can be advantageously reduced.

(Embodiment) A single-cylinder four-cycle engine of a motorcycle provided with an example of a balancer device for an internal combustion engine according to the present invention will be described with reference to FIGS. 1 to 3 are explanatory cross-sectional views of main parts of the engine in a front view, a plan view, and a side view, respectively.
FIG. 4 is a sectional view taken along line IV-IV of FIG.

1 to 3, reference numeral 1 denotes a crankshaft rotatably supported by a crankcase 2, and 3 denotes a crankshaft rotatably supported by the crankcase 2 and are interconnected via a transmission gear train 4. A transmission having a main shaft 5 and a sub-shaft 6, a clutch device 7 mounted on the main shaft 5 of the transmission 3 outside the crankcase 2, 8 a main shaft 5 and a sub-shaft 6 inside the crankcase 2
, A primary balancer weight 9 and a secondary balancer weight 10 rotatably provided around, and a primary balancer provided rotatably about a balancer shaft 11 rotatably supported by the crankcase 2. A balancer device having a weight 12 and a secondary balancer weight 13, 14 is a piston slidable in a cylinder block 15 mounted on the crankcase 2, and 16 is provided on the crankcase 2 to control the transmission 3. Variable speed drive to drive, 17 is a cylinder block
A cylinder head 19, which is mounted on the cylinder head 17 and has an intake / exhaust passage (not shown) communicating with the combustion chamber 18 while forming a combustion chamber 18 with the piston 14, is provided in a head cover 20 mounted on the cylinder head 17. An intake / exhaust device 21 is provided to perform intake / exhaust on the combustion chamber 18. A generator 21 is attached to the end of the crankshaft 1 outside the crankcase 2. Also,
In FIG. 4, reference numeral 22 denotes a kick starter provided on the crankcase 2 for starting the engine.

The crankshaft 1 has a pair of crank webs 23 and 24 housed in a crankcase 2 as shown in FIG.
The crankcase 2 is rotatably supported via bearings 25 and 26. The crankshaft 1 comprises a crank half 27 having a crank web 23 and a crank half 28 having a crank web 24. These are formed by pressing a crank pin 29 formed integrally with the crank web 23 into the crank web 24. They are joined together. The crank pin 29 is connected to the connecting rod 30 by the piston 14.
, And the crankshaft 1 is rotated about its axis with the vertical movement of the piston 14. The end face of the crank web 23 on the side of the crankcase 2 where the crankpin 29 is provided is cut into an inclined shape to be thin, thereby forming a space with the crankcase 2.

The main shaft 5 of the transmission 3 is rotatably supported on the crankcase 2 via bearings 31 and 32 as shown in FIG. 1 and is provided in parallel with the crankshaft 1 so as to protrude from the inside of the crankcase 2. The clutch device 7 is connected to the end.

The clutch device 7 is, as shown in FIG. 2, a clutch outer 33 that is externally inserted around the end of the main shaft 5 in close proximity to the crankcase 2, and is housed inside the clutch outer 33 and rotates integrally with the main shaft 5. The clutch inner 34 is freely mounted, and these are the clutch inner 34 and the lifter plate 35.
Are rotatable integrally and concentrically with the main shaft 5 via a plurality of clutch plates 36 which are mutually superimposed and pressed. The end face of the clutch outer 33 on the side of the crankcase 2 has a one-to-one relationship with a primary drive gear 37 that is rotatably mounted integrally with an end of the crankshaft 1 protruding from the inside of the crankcase 2. A primary driven gear 38 meshed with a gear ratio is fixed concentrically with the main shaft 5, and the primary driven gear 38 is rotatably inserted outside the main shaft 5 via a needle bearing 39 so that the main shaft 5 and the bearing 32 are engaged. The hollow shaft 40 is interposed between the shaft and the outer peripheral surface of the end protruding from the inside of the crankcase 2 and is rotatably fitted integrally therewith by spline coupling.

Therefore, when the crankshaft 1 is rotated as described above, the crank outer 33 and the hollow shaft 40 are moved at the same speed as the crankshaft 1 and in the opposite direction via the primary drive gear 37 and the primary driven gear 38 so that the main shaft 5 rotates. The clutch inner 34 and the main shaft 5 rotate about the axis together with the crank outer 33 and the hollow shaft 40 via a plurality of clutch plates 36 which are superposed and pressed together.

The clutch device 7 includes a push rod 41 slidably inserted into the main shaft 5 toward the lifter plate 35 as shown in FIG. 1, and the push rod 41 is connected to the lifter plate 35 by a clutch driving device (not shown). Is slid in a direction away from the clutch inner 34 so that the clutch plate
36 are released from each other, and at the time of release, the clutch device 7 is disengaged and the clutch inner
34 and the main shaft 5 do not rotate.

The countershaft 6 of the transmission 3 is provided in parallel with the crankshaft 1 rotatably supported on the crankcase 2 via bearings 42 and 43 as shown in FIG. Connected to the main shaft 5 via the row 4,
Similarly to a known transmission, the transmission is rotated in conjunction with the main shaft 5 at several speeds in accordance with the combination of meshing of the transmission gear train 4. A drive sprocket 44 is attached to an end of the sub shaft 6 protruding from the inside of the crankcase 2 so as to be rotatable integrally therewith. The drive sprocket 44 is connected to wheels (not shown) via a chain 45. The rotation of the sub shaft 6 is transmitted to the wheels.

Therefore, the driving force of the engine accompanying the vertical movement of the piston 14 is limited to the crankshaft 1, the clutch device 7, and the transmission 3
Are sequentially output from the countershaft 6 of the transmission 3 to the wheels.

A primary balancer weight 9 (hereinafter referred to as a primary balancer 9) of one of the balancer devices 8 is provided integrally with an end of the hollow shaft 40 in the crankcase 2 as shown in FIG. The main shaft 5 is integrated with the hollow shaft 40 and the clutch outer 33 at the same speed as the crankshaft 1 and in the opposite direction.
Is rotatable around the axis of the. At a position between the primary balancer 9 and the crankcase 2, the secondary balancer weight 10 (hereinafter referred to as a secondary balancer 10) is provided.
The driving gear 46 for rotating the shaft around the sub shaft 6 is a hollow shaft.
40 are provided integrally.

The primary balancer 9 and the drive gear 46 are provided as close as possible to the crank web 23 and the crankcase 2 so that the hollow shaft 40 does not become unnecessarily long. When the crankshaft 1 rotates 180 degrees from the state shown in FIG. 2, the drive gear 46 rotates the crank web 23 and the crankcase 2 as shown by a virtual line in FIG.
And the crank web 23
And the drive gear 46 do not interfere with each other.

The secondary balancer 10 is provided at one end of a hollow shaft 48 rotatably inserted through a needle bearing 47 to the sub shaft 6 via a needle bearing 47 at a position facing the hollow shaft 40 in the crankcase 2 as shown in FIG. A driven gear 49 provided integrally with the other end of the hollow shaft 48 and the driving gear 46 is provided two-to-one with the driving gear 46.
Gear ratio.

Accordingly, when the crankshaft 1 rotates as described above, the primary balancer 9 rotates around the main shaft 5 at the same speed as the crankshaft 1 and in the opposite direction integrally with the hollow shaft 40 as shown in FIG. On the other hand, the secondary balancer 10 is rotated around the sub shaft 6 in the same direction and at twice the speed of the crankshaft 1 via the drive gear 46 and the driven gear 49 via the drive gear 46 and the driven gear 49. The secondary balancer 10 and the driven gear 49 are positioned such that the primary balancer 9 is positioned between the secondary balancer 10 and the driven gear 49 as shown in the phantom line of FIG. Is provided on the hollow shaft 48 so that the hollow shaft 48 does not become unnecessarily long.

The balancer shaft 11 of the balancer device 8 is rotatably supported by the crankcase 2 via bearings 50 and 51 at a position facing the main shaft 5 with the crankshaft 1 interposed therebetween as shown in FIG. The primary balancer weight 12 (hereinafter, referred to as the primary balancer 12) is integrally provided at an end portion in the crankcase 2 thereof. A driven gear 52 meshed with the primary drive gear 37 at a one-to-one gear ratio is rotatable integrally with the balancer shaft 11 at an end of the balancer shaft 11 protruding from the inside of the crankcase 2. It is attached to.

In the middle part of the balancer shaft 11 in the crankcase 2, the secondary balancer weight 13 (hereinafter referred to as “secondary balancer
13) is integrally provided at one end with a hollow shaft 53 rotatably inserted via a needle bearing 54, and
A driven gear 55 provided integrally with the other end of the drive gear is meshed with a drive gear 56 formed on the outer peripheral surface of the crank web 24 at a gear ratio of 2: 1.

Accordingly, when the crankshaft 1 rotates, the primary balancer 12 is integrated with the balancer shaft 11 via the primary drive gear 37 and the driven gear 52 as shown in FIG.
At the same speed and in the opposite direction, while the secondary balancer 13
Is rotated about the balancer shaft 11 in a direction opposite to that of the crankshaft 1 at twice the speed with respect to the crankshaft 1 through the drive gear 56 and the driven gear 55 together with the hollow shaft 53.

Thus, in this engine, a pair of primary balancers
The primary vibration of the engine is reduced by interlocking the crankshafts 9 and 12 with the crankshaft 1 at the same speed and in the opposite direction, and the pair of secondary balancers 10 and 13 is interlocked with the crankshaft 1. By rotating the engine at twice the speed and in the same and opposite directions as the crankshaft 1, secondary vibration of the engine is reduced.

As shown in FIG. 2, the primary balancers 9 and 12 of the balancer device 8 have a line connecting their respective rotation centers at a substantially central portion between the two crank webs 23 and 24 of the crankshaft 1, that is, a cylinder. It is provided at a position passing near the point O where the axis of the cylindrical portion of the block 15 intersects with the axis of the crankshaft orthogonal to the position where the distance from the center is substantially the same,
As a result, the moments generated in the crankshaft 1 by the two primary balancers 9 and 12 cancel each other, and the crankshaft 1
Rotate smoothly.

As shown in FIG. 1, the speed change drive device 16 includes a spindle 57 rotatably supported on one side of the crankcase 2 on a side wall portion, a shift drum 58 rotatably supported on the crankcase 2, The crankcase 2 includes a plurality of shift forks 60 slidably fitted on a shift fork shaft 59 supported in parallel with the main shaft 5 and the sub shaft 6, and each shift fork 60 is shown in FIGS. As shown, it is engaged with the transmission gear train 4 of the transmission 3 and is engaged with a guide groove 58a formed on the outer peripheral surface of the shift drum 58 as shown in the first illustration. This shift drum 58 is similar to that shown in FIGS.
As shown in the figure, the link arm 61 is engaged with the spindle 57 via a link arm 61 rotatably mounted integrally with the end of the spindle 57 in the crankcase 2 so as to rotate with the spindle 57. Is rotated by the swing of. The shift drum 58 has an end protruding from the inside of the crankcase 2 as shown in FIG. 1 connected to a stopper 62 provided on the outside of the crankcase 2 so as to rotate the shift drum stepwise. I have to.

1, the link arm 61 is operated by operating a shift pedal (not shown) connected to an end of the spindle 57 protruding from the inside of the crankcase 2 in the same manner as the known shift drive device in FIG. The shift drum 58 is rotated in a stepwise manner, and at this time, each shift fork 60 is guided by the guide groove 58a of the shift drum 58 to slide the shift fork shaft 59 in the axial direction, thereby changing the speed change gear train. Some of the transmission gears 4 move the main shaft 5 or the sub shaft 6 in the axial direction to change the meshing combination of the transmission gear train 4, so that the rotation transmission from the main shaft 5 to the sub shaft 6 is shifted.

The spindle 57 is returned to its original position after being rotated by a predetermined amount by a return spring 63 provided at an end in the crankcase 2.

The generator 21 is rotatably mounted integrally with an end of the crank half 28 of the crankshaft 1 protruding from the inside of the crankcase 2 on the side opposite to the clutch device 7 as shown in FIG. And a stator 66 fixed to the inner surface of a generator cover 65 mounted on the crankcase 2 and housed in the flywheel 64. The crankshaft 1 is turned in the same manner as a known generator. When the flywheel 64 is moved, the flywheel 64 rotates around the stator 66 together with the crankshaft 1 to generate power, thereby charging a battery (not shown).

As shown in FIG. 1, the intake / exhaust device 19 includes bearings 67, 68 between the cylinder head 17 and the head cover 20.
And a plurality of rocker arms 71 swingably supported by a rocker arm shaft 70 provided on the head cover 20 in parallel with the cam shaft 69. A cam driven sprocket 72 rotatably mounted integrally with an end of the clutch half 28 is formed on the outer peripheral surface of the small diameter portion 28a of the clutch half 28 at a position between the generator 21 and the crankcase 2. Chain 74 on cam drive sprocket 73
, Whereby the camshaft 69 is rotated with the rotation of the crankshaft 1. And each rocker arm
Reference numeral 71 is engaged with a cam 69a formed on the cam shaft 69, and is also engaged with an intake / exhaust valve (not shown) for opening and closing an intake / exhaust passage communicating with the combustion chamber 18.

In the intake / exhaust device 19, as in a known engine,
The rotation of the camshaft 69 in synchronization with the crankshaft 1 opens and closes the intake / exhaust valve via the rocker arm 71, and the combustion chamber
Intake and exhaust of 18 are performed.

The kick starter 22 includes a crankcase 2 and a clutch cover mounted on the crankcase 2 as shown in FIG.
75 and a starter spindle 76 rotatably supported by
A starter gear 77 rotatably supported about an intermediate portion of the starter spindle 76 in the crankcase 2, the starter gear 76 being connected to the driven gear 49 of the hollow shaft 48 having the secondary balancer 10. A ratchet portion 77a is formed on the end surface on the clutch cover 75 side. Then, the starter gear 77 and the clutch cover 75
A drive ratchet 78 which is integrally rotatably and slidably fitted to the starter spindle 76 and urged in a direction away from the ratchet portion 77a is provided at a position between the two.

In such a kick starter 22, the starter spindle 76
By operating a kick pedal (not shown) connected to the outside of the clutch cover 75, the drive ratchet 78 slides and engages with the ratchet portion 77a of the starter gear 77, and the starter spindle 76 is integrated with the drive ratchet 78. , Whereby the starter gear 77 is rotated, and the hollow shaft 48 is rotated. At this time, the hollow space 48 rotates in the same direction in conjunction with the crankshaft 1 as described above, whereby the piston 14 is moved up and down to start the engine.

In this embodiment, the kick starter is used. However, a pulley may be provided at the end of the starter spindle 76, and a recoil starter in which a rope is wound around the pulley a plurality of times may be used. It may be provided via.

The starter spindle 76 is returned to its original position after being rotated by a predetermined amount by a return spring 79 provided at an end in the crankcase 2.

Next, in the engine having such a configuration, the above-described configuration of the balancer device 8, which is a main part of the present invention, will be described with reference to FIG.

In the balancer device 8, the primary balancer 9 and the secondary balancer 10 are rotatably provided on the main shaft 5 and the sub shaft 6 via hollow shafts 40 and 48, respectively, and the main shaft 5 and the sub shaft 6 are connected to these balancers. The balancer device 8 is used as a shaft, and the other primary balancer 12 and secondary balancer 13 are rotatably provided on one balancer shaft 11, so that the number of dedicated balancer shafts is reduced as much as possible. The number of parts has been reduced.

The primary balancer 9 is driven by a primary drive gear 37, a primary driven gear 38, and a hollow shaft 40 by the clutch device 7 as driving means for rotating the main shaft 5 of the transmission 3.
In this case, a dedicated driving means for rotating the primary balancer 9 is not required, and the number of parts of the balancer device 8 is reduced.

In addition, by providing a drive gear 46 integrally with the primary balancer 9 and the clutch device 7 at both ends of the hollow shaft 40, the hollow shaft 40 is effectively utilized spatially,
The secondary balancer of the hollow shaft 48 on the sub shaft 6 by the drive gear 46
By rotating the rotary shaft 10, the hollow shafts 40 and 48 are effectively and effectively used, and the parts dedicated to the balancer device 8 are reduced as much as possible.

Furthermore, since the primary balancer 9 and the clutch device 7 are provided at both ends of the hollow shaft 40, the rigidity of the hollow shaft 40 is easily ensured by balancing the weight of the two, and in this balancer device 8, The hollow shaft 40 is made compact while ensuring sufficient rigidity to reduce its weight and size.

Further, since the primary balancer 9 and the clutch layer 7 are rotatable integrally and the gear ratio of the primary drive gear 37 and the primary driven gear 38 is 1: 1, the clutch device is rotated when the crankshaft 1 rotates. 7 and the rotational torque applied to the main shaft 5 become small, and therefore, the clutch device 7
In addition, the required strength of the main shaft 5 is reduced. In the engine of the present embodiment, these are made relatively compact, and the size and weight of the engine are reduced.

As described above, in the balancer device 8, the dedicated parts are reduced as much as possible and the number of parts is greatly reduced, and the hollow shaft 40 of the primary balancer 9 and the hollow shaft 48 of the secondary balancer 10, etc. Are effectively utilized spatially and operatively, and their weight and size are reduced, so that the engine is small and light.

In the balancer device 8, the primary balancer 9 is connected to a hollow shaft.
Although the clutch device 7 is provided integrally with the hollow shaft 40 and the clutch device 7 is spline-coupled to the hollow shaft 40, for example, the primary balancer 9 may be spline-coupled to the hollow shaft 40 and the clutch device 7 may be integrally formed with the hollow shaft 40. Needless to say, the same effects as above can be obtained. Then, according to the configuration of the present embodiment, as described below, the assembly of the hollow shaft 40, the clutch device 7, and the like can be performed more easily in the engine assembling operation.

That is, in the engine of the present embodiment, the crankcase 2 is substantially divided right and left on the rotation surface of the connecting rod 30, but the clutch device 7 and the hollow shaft 40 are not divided.
When assembling, the hollow shaft 40 integrated with the primary balancer 9 is first extrapolated to the main shaft 5 with the crankcase 2 on the clutch device 7 side removed, and then the clutch device 7 is mounted after the crankcase 2 is mounted. Is mounted on the hollow shaft 40 and the main shaft 5.

Further, even when the crankcase 2 is vertically divided at the position of the main shaft 5, according to the configuration of the present embodiment, the clutch device 7 can be mounted after the crankcase 2 is mounted. These can be assembled without any trouble.

As described above, in the engine of the present embodiment, the clutch device 7, the hollow shaft 40, and the crankcase 2 can be separately assembled to the engine, and these assembling operations are relatively easy.

Next, a second example of the balancer device of the present invention will be described with reference to FIGS. FIG. 5 and FIG. 6 are explanatory cross-sectional views of main parts of the engine in side and front views, respectively.

This engine has the same basic configuration as that of the above-described engine. As shown in FIG. 5, a crankshaft 80 is connected to a piston 82 via a connecting rod 81, and as shown in FIG. And a primary drive gear 84. Then, as shown in FIG.
The main shaft 86 and the sub shaft 87 of 85 are connected via a transmission gear train 88, and a clutch device 89 is mounted concentrically on the end of the main shaft 86, and a clutch device 89 at the end of the main shaft 86 A hollow shaft 92 integrally provided with a primary balancer weight 91 (hereinafter, referred to as a primary balancer 91) of the balancer device 90 is provided at an inner position.

As shown in FIG. 6, the hollow shaft 92 is externally concentrically inserted into the end of the main shaft 86 so that the main shaft 86 has a needle bear link 93.
Is fitted by spline coupling to the outer peripheral surface of one end of the cylindrical body 94 rotatably supported via
Along with 94, it is rotatable around a main shaft 86. Further, a clutch outer 89a of a clutch device 89 is fixed to the other end of the cylindrical body 94, whereby the hollow shaft 92 and the clutch device 89 are rotatable integrally around the main shaft 86 via the cylindrical body 94. Have been. In addition, the hollow shaft 92 is integrated with this,
A primary driven gear 95 is provided concentrically with the main shaft 86,
The primary driven gear 95 is meshed with the primary drive gear 84 at a gear ratio of 1: 1.

In FIG. 5, reference numerals 96 and 96 denote shift forks engaged with a transmission gear train 88 (shown in FIG. 6) in the same manner as the shift fork 60 of the transmission drive device 16.

In FIG. 6, reference numeral 97 denotes a driving sprocket mounted on the end of the counter shaft 87 and connected to wheels (not shown) via a chain 98. Reference numeral 99 denotes an intake / exhaust device (not shown) similar to the engine described above. For driving through crankshaft 8
0 is a driven sprocket, 101 is a driven gear fitted to the cylindrical body 94 and meshed with the drive sprocket 102 for a kick starter, 103 is a bearing for supporting an intermediate portion of the cylindrical body 94, 104 is a cylindrical body. It is a damper spring provided between the body 94 and the clutch outer 89a.

In such an engine, the primary driven gear 95, the hollow shaft 92 and the primary balancer 91 provided integrally as described above are rotated by the rotation of the crankshaft 80 accompanying the vertical movement of the piston 82.
Is rotated about a main shaft 86 via a primary drive gear 84, and the clutch device 89 and the main shaft are
86 is rotated about its axis, and the countershaft 87 is further rotated via the transmission gear train 88, so that the driving force of the engine is output to the wheels. At this time, the primary drive gear 84 and the primary driven gear 95 are meshed at a gear ratio of one to one, so that the primary balancer 91, the hollow shaft 92, the clutch device 89, etc. rotate in the opposite direction at the same speed as the crankshaft 80. The primary vibrations of the engine are reduced.

Therefore, also in this engine, a dedicated driving means for rotating the primary balancer 91 is not required similarly to the above-mentioned engine, and the number of parts of the balancer device 90 is reduced, and the weight and size of the balancer device 90 can be reduced. It is planned.

Also, like the above-mentioned engine, the primary drive gear
Since the gear ratio of the gear 84 and the primary driven gear 95 is 1 to 1, the rotational torque applied to the clutch device 89 and the main shaft 86 is small, and therefore the required strength of the clutch device 89 and the main shaft 86 is reduced, so that the size and size of these components can be reduced. The weight has been reduced.

Further, in this engine, the driven gear 10 is disposed between the clutch device 89 and the primary driven gear 95 as shown in FIG.
1, a ball bearing 103, a damper spring 104, and the like are provided to achieve effective use of space.

Next, a third example of the balancer device of the present invention will be described with reference to FIG. FIG. 7 is an explanatory sectional view of a main part of the engine.

This engine has the same basic configuration as the second example described above, and the common configuration will be described with the same reference numerals as those of the engine of the second example.

That is, this engine has a main shaft 86 of a transmission 85 having the same configuration as the engine of the second example, a clutch device 89, a primary driven gear 95 connected to the clutch device 89 and a crankshaft (not shown), and A driven gear 95; a hollow shaft 92 provided integrally with the driven gear 95; and a balancer device 90 having a primary balancer 91; and a self-starter device 105 and an intermediate shaft 107 having a generator 106 mounted at one end. The other end of 107 is connected to a clutch device 89 via a starter drive gear 108 meshed with the primary driven gear 95 at a gear ratio of 2: 1.

Then, the starter clutch 1 of the self-starter device 105
09 is rotatably mounted integrally with a substantially central portion of the intermediate shaft 107, and is connected to the starter motor 110 by a driving gear 111 and a driven gear.
It is connected via 112.

The balancer device 90 having the primary balancer 91 further includes a secondary balancer weight 113 (hereinafter, referred to as a secondary balancer 113).
09 is provided integrally with the housing 109a.

In such an engine, the self-starter device 105 drives the drive gear 111 and the driven gear 11
The engine is started by rotating the intermediate shaft 107 via the starter clutch 109 and the starter clutch 109, and further rotating the crankshaft via the starter drive gear 108 and the primary driven gear 95. During operation of the engine, the rotation of the crankshaft causes the intermediate shaft 1 to rotate through the primary driven gear 95, the clutch device 89, and the starter drive gear 108 in that order.
07 is rotated. At this time, since the gear ratio between the primary driven gear 95 and the starter driving gear 108 is 2: 1, the intermediate shaft 107 is rotated at twice the speed of the crankshaft, and thus the secondary balancer 113 is moved to the starter clutch 109. Housing
It is rotated together with 109a at twice the speed of the crankshaft, thereby reducing the secondary vibration of the engine.

As described above, in this engine, the secondary balancer 113 is provided integrally with the housing 109a of the starter clutch 109 to rotate the engine at the time of operation of the engine. Therefore, the number of components of the balancer device 90 is reduced, and the weight and size of the balancer device 90 are reduced.

(Effects) As is apparent from the above description, according to the balancer device for an internal combustion engine of the present invention, a balancer weight is integrally provided on a hollow shaft rotatably supported around a main shaft of a transmission, and a clutch device is provided. The balancer weight can be interlocked with the crankshaft by using a driving means such as a clutch device for interlocking the main shaft with the crankshaft, and the balancer weight can be rotated by being provided integrally and rotatably. Therefore, it is possible to reduce the number of parts constituting the balancer device without providing a dedicated driving means for this purpose, and to reduce the weight and size of the engine.

Further, at this time, since the main shaft of the transmission is rotated at the same speed as the crankshaft together with the clutch device, the rotational torque applied to the clutch device and the main shaft of the transmission device is reduced, and therefore the required strength for the transmission device and the clutch device And the size and weight can be reduced.

Further, when the clutch device is connected to the crankshaft via the primary driven gear and the primary drive gear, the clutch device is connected to the hollow shaft via the clutch device, which is a heavy object that rotates integrally with the hollow shaft from the crankshaft. Since the torque is transmitted, the hollow shaft is not twisted by the torque from the crankshaft, and the required strength is reduced.

Further, when the balancer weight and the clutch device are provided at both ends of the hollow shaft rotatably supported on the main shaft,
By balancing the weights of the balancer weight and the clutch device, the required rigidity of the hollow shaft can be easily secured, and the hollow shaft can be made compact to reduce its weight and size. The space between the balancer weight and the clutch device can be effectively used.

Further, when the balancer weight is integrally provided at one end of the hollow shaft accommodated in the case, and the clutch device is fitted to the outer peripheral surface of the other end of the hollow shaft protruding out of the case, The balancer weight, the case, and the clutch device can be separately assembled to the internal combustion engine, and the assembling work can be easily performed.

Further, when a driving gear for rotating another balancer weight is provided on the hollow shaft, the hollow shaft having the balancer weight can be effectively utilized as a driving means for rotating the other balancer weight, The number of components can be reduced without providing a dedicated driving unit.

Further, when the other balancer weight is a secondary balancer weight, it is merely connected to the hollow shaft through a pair of gears, and the secondary balancer weight is linked to the crankshaft to make the secondary balancer weight of the engine smaller. Vibration can be reduced.

Further, when the primary balancer weight is rotatably provided between the secondary balancer weight and the driven gear provided integrally with the secondary balancer weight, the space between the secondary balancer weight and the driven gear is reduced. By effectively utilizing the both balancer weight and both gears and shortening the length in the direction of the main shaft, the configuration of the balancer device can be reduced in size, and the primary balancer weight and drive gear can be used. The main shaft to be supported can be shortened, and the size and weight of the internal combustion engine can be reduced.

[Brief description of the drawings]

1 to 3 are explanatory cross-sectional views of a main part of an engine provided with an example of the balancer device of the present invention in a front view, a plan view, and a side view. FIG. 4 is a line IV-IV in FIG. FIG. 5 is a sectional view of the balancer device according to the present invention.
FIG. 7 is an explanatory sectional view of a main part of a side view and a front view of an engine having the example of FIG. 7, and FIG. 7 is an explanatory sectional view of an essential part of an engine having a third example of the balancer device of the present invention. 1,80 ... Crank shaft, 2 ... Case 3,85 ... Transmission device, 4,88 ... Transmission gear train 5,86 ... Main shaft, 6,87 ... Sub shaft 7,89 ... Clutch device, 8,90 Balancer device 9,91 Primary balancer weight 10,113 Secondary balancer weight 37,84 Primary drive gear 38,95 Primary driven gear 40,92 Hollow shaft, 46 … Drive gear 49 …… driven gear

Claims (8)

(57) [Claims] 1. A transmission comprising a main shaft interlocked with a crankshaft via a clutch device and a subshaft interlocked with the main shaft via a transmission gear, and a primary balancer rotating at least in synchronization with the crankshaft. An internal combustion engine having a balancer device having a weight, wherein the balancer weight is integrally provided on a hollow shaft rotatably supported concentrically around the main shaft, and the clutch device is mounted on the hollow shaft. A balancer device for an internal combustion engine, wherein the balancer device is rotatably provided integrally with the crankshaft and is connected to the crankshaft so as to rotate at a constant speed and in a reverse direction. 2. The clutch device according to claim 1, wherein the clutch device is connected to the crankshaft via a primary driven gear rotatably provided integrally with the clutch device and a primary drive gear provided on the crankshaft. The balancer device for an internal combustion engine according to claim 1, wherein 3. The balancer device for an internal combustion engine according to claim 1, wherein said balancer weight is provided at one end of said hollow shaft, and said clutch device is provided at the other end of said hollow shaft. . 4. The balancer weight of the hollow shaft, wherein the balancer weight is integrally provided at one end of the hollow shaft, and the clutch device is fitted and connected to an outer peripheral surface of the other end of the hollow shaft. 2. An internal combustion engine according to claim 1, wherein one end of the internal combustion engine is accommodated in a case accommodating the transmission, and the other end for coupling the clutch device protrudes out of the case. Balancer device. 5. The apparatus according to claim 1, further comprising another balancer weight different from said primary balancer weight, wherein a driving gear for rotating said other balancer weight is provided integrally with said hollow shaft. Balancer device for internal combustion engines. 6. The balancer device for an internal combustion engine according to claim 5, wherein said another balancer weight is a secondary balancer weight. 7. A driven gear integrally provided with the secondary balancer weight is meshed with the drive gear, and the primary balancer weight is rotatably provided between the secondary balancer weight and the driven gear. 7. The balancer device for an internal combustion engine according to claim 6, wherein: 8. The balancer device for an internal combustion engine according to claim 7, wherein said secondary balancer weight is rotatably provided on said counter shaft.