JPH04331842A - Two-axis type balancer device for engine - Google Patents

Abstract

PURPOSE:To lower the center of gravity of an engine by positioning a balancer shaft at a low position by allowing the axis position line connecting the axis center of a balancer on both the sides of a crankshaft to cross the axis position line connecting the crankshaft and the main shaft of a transmission and to pass through below the axis center of the crankshaft. CONSTITUTION:The case 30 of an engine 2 consists of the upper and lower cases 31 and 32 having an axis position line 30a as dividing surface. In the case 30, a crankshaft 44 and the main shaft 46 and the driven shaft 47 of a transmission 45 are supported by a bearing installed on the dividing surface on the axis position line 30a. Before and behind the crankshaft 44, balancer shafts 48 and 49 are supported in parallel to the crankshaft 44. In this case, both the balancer shafts 48 and 49 are arranged so that the axis position line 50 passing through each center line crosses the axis position line 30a connecting the crankshaft 44 and the main shaft 46 and passes through under the center of the crankshaft 44. Further, the axis center of the balancer shaft 49 positioned on the transmission 45 side is arranged above the intermediate part of the main shaft 46 and the driven shaft 47.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-shaft balancer device for preventing vibrations in engines for driving motorcycles, tricycles, etc.

0002

2. Description of the Related Art A system in which a transmission is disposed on one side of a crankshaft and shafts of a two-shaft balancer are disposed on both sides is known, for example, from Japanese Patent Laid-Open No. 2-163539. In this conventional technology, the balancer is driven using the gear of the primary reduction gear provided between the crankshaft and the main shaft of the transmission, and one drive gear is connected to the drive gear on the crankshaft side of the primary reduction gear. The other balancer is arranged above the crankshaft and the main shaft of the transmission and is linked to a large diameter driven gear provided on the main shaft.

According to this configuration, the other balancer is placed above the large-diameter driven gear, so it is located at a high position, and the balancer has a large weight because it includes the balancer gear, shaft, eccentric weight, etc. As a result, the center of gravity of the engine becomes high, making it difficult to lower the center of gravity of a vehicle using the engine. This tendency is even more pronounced in so-called backpack ACG engines, in which the alternator is located behind the cylinder and above the transmission.

0004

SUMMARY OF THE INVENTION An object of the present invention is to lower the center of gravity of the engine by locating the balancer shaft at a lower position.

[0005]

[Means for Solving the Problems] The means for solving the above problems in the present invention is to arrange a transmission having a main shaft and a slave shaft parallel to the crankshaft on one side, and interlock with the transmission on both sides of the crankshaft. In an engine in which a pair of balancers are arranged in parallel, the shaft position line connecting the shaft centers of both balancers crosses the shaft position line connecting the shaft centers of the crankshaft and the main shaft of the transmission, and is located below the shaft center of the crankshaft. The shaft of both balancers is arranged so as to pass through the balancer.

[0006]

[Operation] By using the above structure, it is easy to lower the combined center of gravity of the balancers on both sides, and an engine with a low center of gravity can be obtained.

[0007]

Embodiments Hereinafter, embodiments will be described with reference to the drawings. In FIG. 1, reference numeral 1 denotes a motorcycle equipped with an engine 2 of the present invention, and the engine 2 is equipped with a well-known two-shaft balancer for damping its secondary vibrations. Motorcycle 1 is
The engine 2 has a main frame 4 extending left and right rearward from the head pipe 3, and a hook-shaped subframe 5 connected to the main frame 4.
7, 8, and 9 are fixed to both frames 4 and 5.

A front fork 11 supporting a front wheel 10 is supported on the head pipe 3, and a subframe 5
A pair of left and right rear arms 13 that support a rear wheel 12 are pivotally connected to the rear arms 13 by a pivot 14 . A rear arm cover 15 is fixed to the upper surface of the rear arm 13, forming a generally triangular space when viewed from the side, and the rear arm cover 15 is integrally molded from a resin material and has an aluminum surface painted. , a beam 16 that is U-shaped in top view and surrounds the front part of the rear wheel 12, a stay 17 that extends forward and downward from the front part of the beam 16, a fender part 18 that extends upward from the beam 16, and a chain cover part 19. .

One vertex of a triangular lever 21 is pivotally attached to a bracket 20 on the front lower surface of the rear arm 13.
The other two vertices have bars 2 connected to the subframe 5.
2 and a cushion 23 are connected to support the vehicle body. Further, a seat rail 24 and a rear stay 25 extend from the subframe 5. In the figure, 26 is a fuel tank, and 27 is a seat.

The case 30 of the engine 2 has a lower case 31 and an upper case 32 whose planes are cut along the axis position line 30a. A forward-inclined cylinder 33 extends from the upper case 32, and a cylinder head 34 and a head cover 34a. Carburetor 3 on the back
5. An air cleaner 36 and a duct 37 are arranged in this order, and an exhaust pipe 38 is connected to the front surface. Also lower case 31
An oil pan 39, a water-cooled oil filter 40, and a water pump 41 are attached to the engine, and a radiator 42 in front of the engine is connected to the water pump 41.

Inside the case 30, a crankshaft 44, a main shaft 46 and a slave shaft 47 of a transmission 45 (FIG. 3) are arranged along a shaft position line 30a.
Balancer shafts 48 and 49 parallel to the crankshaft 44 are supported at the front and rear of the crankshaft 44, and the positions of both balancer shafts 48 and 49 pass through the center of the crankshaft 44. The shaft position line 50 indicates the crankshaft 44 and the main shaft 4.
6, and passes below the center of the crankshaft 44. In the figure, 51 is a fixed output sprocket around which a chain 52 for driving the rear wheel 12 is wound around the slave shaft 47, and 53 is a generator shaft.

Each part of the engine 2 will be described in detail with reference to FIGS. 2, 3, and 4. The crankshaft 44 has a
The pistons 54 are connected via connecting rods 55, and the outermost web is formed with a primary drive gear 56 of the primary reduction gear P, the third web is formed with a balancer drive gear 57, and the other end is formed with a balancer drive gear 57. A starter gear 59 is installed via a one-way clutch 58. As is clear from FIG. 2, the drive gear 56 has the smallest diameter, and the balancer drive gear 57 and the starter gear 59 have larger diameters in this order. transmission 4
An inner member 61 of a main clutch 60 is fixed to the main shaft 46 of the main clutch 60, and an outer member 62 is rotatably supported, and a serial gear type primary driven gear 63 of a primary reduction gear P is fixed to the outer member 62. It meshes with the drive gear 56. The pressure plate 64 of the clutch is controlled by a rod 65 passing through the main shaft 46 and a piston 66 to intermittent power, and when the main clutch 60 is connected, the power is transferred to the output of the slave shaft 47 via a gear train 67. sprocket 5
1.

As shown in FIG. 4, a front balancer shaft 48 is arranged on one side of a balancer drive gear 57 on the crankshaft 44, and a rear balancer shaft 48 is arranged on the other side via an intermediate shaft 69 having an idle gear 68. A shaft 49 is arranged.

The front balancer 70 is connected to the front balancer shaft 48.
and a balancer gear 71 having a sleeve 72 supported on the shaft 48, and an eccentric balancer weight 73 loosely fitted onto the sleeve 72 and coupled via a rubber damper 74.
Equipped with

The front balancer shaft 48 has a portion that supports the sleeve 72 that is slightly eccentric with respect to the portions that fit into the holes in the lower case 31 at both ends, and the outer end of the shaft 48 has a
An adjustment arm 75 shown in FIG. 5 is fixed and secured by a bolt 77 passing through an arcuate hole 76 concentric with the shaft 48. This adjusts the position of the eccentric portion of the front balancer shaft 48, adjusts the engagement between the balancer drive gear 57 and the balancer gear 71, and prevents the generation of noise.

Furthermore, the intermediate shaft 69 and the rear balancer shaft 49
The gear 57 also has an eccentric portion similar to the front balancer shaft 48 and adjustment arms 78 and 79 similar to the adjustment arm 75.
, 68, and 81 are adapted to be adjusted. The rear balancer 80 has the same structure as the front balancer 70 and a balancer weight 7 having the same mass as the balancer weight 73.
3a, and the balancer gear 81 is driven via the idle gear 68, so it rotates in the opposite direction to the front balancer 70. The damping effect of both balancers 70, 80 is the same as that of the well-known one.

[0017] The alternating current generator 83 (ACG) is connected to the cylinder 3
3 and above the transmission 45 (Fig. 2), forming a so-called backpack ACG type engine.
3 is a flexible joint 87 which is equipped with a spring damper 85 and a generator gear 84 of a ceramic gear type that meshes with the primary driven gear 63 without back clearance, and which is divided in the middle and has a rubber damper 86 interposed therebetween.
It has a connected structure.

An oil chamber 89 is formed in the upper case 32 surrounding the generator shaft 53, and an inlet 88 communicates with the oil chamber 89. The outer surface of the oil chamber 89 is closed with a cap 90, and both sides are closed by sealed bearings 91, 92. Closed. Oil passing through the crank bearing is supplied into the oil chamber 89, and the oil flows from there into the horizontal hole-shaped entrance 93a of the generator shaft 53.
The oil is introduced into the central oil passage 93 from the outlet 93b, etc., and the gear 8
4. Supplied to the spring damper 85, etc.

In FIG. 4, the small gear side of the two-stage idle gear 95 meshes with the starting gear 59, and the pinion 97 of the starting motor 96 meshes with the large gear side, thereby energizing the starting motor 96. The crankshaft 44 is driven via the one-way clutch 58. The starting motor 96 is disposed at the front of the lower case 31 as shown in FIG. 1, and is mounted parallel to the crankshaft 44 by fitting the front bearing part 96a into the lower case 31 as shown in FIG. . Starting motor 96
By arranging them in this way, the starting motor 96,
By positioning the idle gear 95 and the like lower than the crankshaft 44, the center of gravity of the entire engine can be lowered.

In FIG. 2, reference numeral 100 denotes a pump shaft, which drives the water pump 41 and an oil pump (not shown), and a sprocket 101 attached to this shaft is a pump-driving sprocket that rotates integrally with the clutch outer member 62. 102
, are driven via a chain 103.

Oil coming out of an oil pump (not shown) enters a water-cooled oil filter 40 through an oil passage 105 having a relief valve 104, and flows through an outlet pipe 106 to the main gallery 1.
07 and is supplied to each part of the engine. Furthermore, oil supply passages 108 and 109 passing through the case wall in parallel with the main gallery 107 are branched before and after the main gallery 107, and the oil supply passage 108 communicates with an oil passage 110 (FIG. 4) for lubricating the front balancer 70, and an oil supply passage 109. The oil reaches the rear balancer 80 and is supplied to the transmission shaft from an oil path 111 (FIG. 3) which branches off.

In the embodiment described above, the balancer driving gear 57 is provided at a position axially apart from the gears 56, 63 of the primary reduction gear P, so that the outer side of the driven gear 63, which has a large diameter, is particularly important among the gears 56, 63. The idle gear 68 and the rear balancer gear 81 can be arranged inward from the radial line, and can be easily arranged so that the shaft position line 50 connecting the front and rear balancer shafts passes below the center of the crankshaft 44.

The embodiment of FIG. 9 has front and rear balancers 70, 8.
The shaft position line 50 is further lowered by inserting one idle gear into each of the drive systems of 0. In the figure, 115 is an idle gear meshed between the balancer drive gear 57 and the front balancer gear 71, and 116 is an idle gear 68.
By doing so, the positions of both balancers 70 and 80 can be lowered.

In the embodiment shown in FIG. 10, the drive system for the front balancer 70 is the same as that shown in FIG. 9, but the rear balancer 80 is driven from the primary driven gear 63 of the primary reduction gear P via the idle gear 117. . In this embodiment, the rear balancer 80 is at a relatively high position, but the front balancer 70 is at a low position away from the balancer drive gear 57, so the shaft position line 50 is at a low position.

The embodiment of FIG. 11 uses the water pump 41 described above.
A gear is used in a drive system for driving an oil pump (not shown), and the rear balancer 80 is driven using the gear. In the figure, 118 is a pump drive gear that is concentric with the main shaft 46 and rotates together with the clutch outer member 62, 119 is a pump driven gear fixed to the pump shaft 100, and the idler 120 is connected to the pump drive gear 118 and the rear balancer gear 8.
1, and the gear ratio of the drive system is such that both balancers 70, 80 rotate at the same speed and in opposite directions.

In this embodiment, the pump drive gear 11
8 has a small diameter, and the rear balancer gear 81 has an even smaller diameter, so the rear balancer 80 is in a lower position and the front balancer 7
0 is also at a low position, so the axis position line 50 passes through the low position.

In the embodiment shown in FIG. 12, gears 118 and 119 are used to drive the pump shaft 100, and the balancer gear 121 of the rear balancer 80 is meshed with the pump drive gear 118, and the balancer gear 71 of the front balancer 70 is , are directly meshed with the balancer drive gear 57.

In this embodiment, the front balancer 70 is at a relatively high position, but because the distance between the shafts of gears 118 and 121 is small, the rear balancer 80 is at a low position, and the shaft position line 5
0 is also a low position.

In the embodiment shown in FIG. 13, a rear balancer drive gear 123 driven by a clutch outer member is provided concentrically with the main shaft 46 of the transmission, and the rear balancer gear 8 is connected to the drive gear 123.
The front balancer 70 meshes with the balancer drive gear 57 of the crankshaft 44.

In this embodiment as well, the gears 123 and 81 are both small in diameter and the distance between the shafts is small, so the rear balancer 80 is in a low position and the shaft position line 50 is also in a low position.

The embodiment shown in FIG. 14 is different from the embodiments shown in FIGS.
3 has the same arrangement, but the arrangement of the starting motor 96 is different. In this embodiment, in addition to the generator gear 84 driven by the driven gear 63 of the primary reduction gear, a large diameter gear 84a is used.
is fixed to the rotating part of the generator. The starting motor 96 is disposed near the gear 84a and has a pinion 97.
, an idle gear 95 is arranged to interlock with the gear 84a.

Therefore, when the starting motor 96 is energized, its rotation is transmitted to the crankshaft 44 by the generator 83 and the gears 84, 63, 56, and a starting action is performed.

In this embodiment, since the shaft position line 50 is at a low position, even if the starting motor 96 is placed at a high position as shown in the figure, the rise in the center of gravity can be suppressed to a low level.

The embodiment shown in FIG. 15 is the same as the embodiment shown in the previous figure in that the alternating current generator 83 and starting motor 96 are arranged at the top, but the alternating current generator 83 is installed near the slave shaft 47 and the cylinder A starting motor 96 is disposed near the cylinder 33 and away from the cylinder 33, and drives the starting gear 58 of the crankshaft 44 via an idle gear 95.

In this embodiment, since the starting motor 96 is located lower than in the embodiment shown in the previous figure, it is possible to further suppress the rise in the center of gravity.

[0036]

As described above, in the invention of claim 1, since the axis position lines of the front and rear balancers are lower than the center of the crankshaft, the center of gravity of the engine is lowered, and when mounted on a vehicle, the center of gravity of the vehicle can be lowered. can.

Further, in the invention of claim 2, since the balancer disposed on the transmission side is disposed at a low position midway between the upper parts of the gears provided on the main shaft and the vertical shaft, there is an effect that the center of gravity can be further lowered.

[Brief explanation of drawings]

[Fig. 1] Side view of a motorcycle equipped with the engine of the present invention

[Figure 2] Side view of the engine

[Figure 3] Longitudinal cross-sectional view of the same as above

[Figure 4] Transverse cross-sectional view of the same as above

[Figure 5] Front view of eccentric shaft adjustment section

[Figure 6]
Rear arm cover side view

[Figure 7] Bottom front view of the engine

[Figure 8] Enlarged view of eccentric shaft part

[Figure 9] Balancer drive system layout diagram of another embodiment

[
Figure 10: Balancer drive system layout diagram of another embodiment

[Figure 1
1] Balancer drive system layout diagram of other embodiments

[Figure 12]
Balancer drive system layout diagram of other embodiments

[Figure 13]
Balancer drive system layout diagram of other embodiments

[Figure 14] Balancer drive system layout diagram of another embodiment

[Figure 15] Balancer drive system layout diagram of another embodiment

[Explanation of symbols]

30a, 50 Axis position line 44
Crankshaft 45 Transmission 46
Main shaft 47 Slave shaft 48, 49 Balancer shaft 70, 80 Balancer P
Primary reducer

Claims (2)

[Claims] Claim 1: In an engine in which a transmission having a main shaft and a slave shaft parallel to the crankshaft is disposed on one side of the crankshaft, and a pair of balancers that interlock with the transmission are disposed on both sides of the crankshaft in parallel, both balancers Both balancer shafts are arranged so that the axis position line connecting the axis of the crankshaft and the main shaft of the transmission crosses the axis position line connecting the axis of the crankshaft and the main shaft of the transmission, and passes below the axis of the crankshaft. A two-shaft balancer device for the engine. 2. The two-shaft balancer device for an engine according to claim 1, wherein the axial center of the balancer disposed on the transmission side is located above an intermediate position between the main shaft and the slave shaft of the transmission.