JP3614570B2 - Engine balancer equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a balancer device for an engine in which a balancer shaft integrally provided with a balancer gear is supported on a balancer shaft installed inside a casing.
[0002]
[Prior art]
Such an engine balancer device is already known from Japanese Patent Application Laid-Open No. 4-277349.
[0003]
[Problems to be solved by the invention]
By the way, the balancer weight assembled inside the casing needs to be phase-aligned so that the phase (that is, the phase of the balancer gear formed integrally with the balancer weight) has a predetermined relationship with the phase of the crankshaft. There is. However, since the balancer weight is generally mounted at a deep position inside the casing that is difficult for the operator to reach and is difficult to see, the phase adjustment operation is troublesome.
[0004]
The present invention has been made in view of the above circumstances, and an object thereof is to enable easy and reliable phase alignment of a balancer gear integrally having a balancer weight.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the invention described in claim 1 is characterized in that a balancer weight integrally having a balancer gear is rotatably supported on a balancer shaft installed inside a casing, and the balancer gear is connected to a crankshaft. Shi,A phase alignment mark for phase alignment of the balancer gear at the time of assembly is provided so as to oppose the outer periphery of the balancer gear, and an opening is provided in the casing so that the opposing portion of the balancer gear and the phase alignment mark can be seen from the outside. FormedIn the engine balancer device,Balancer gear when assembledA rib provided with the phase alignment mark is provided on the inner wall of the casing to position theIt is characterized by that.
[0007]
And claims2The invention described inA balancer weight that integrally has a balancer gear is rotatably supported by a balancer shaft installed inside the casing, and the balancer gear is connected to the crankshaft. In the balancer device for an engine, which is provided so as to face the outer periphery of the balancer gear, and has an opening formed in the casing so that the facing portion of the balancer gear and the phase alignment mark can be seen from the outside.An idle gear with a balancer gear on the idle shaftInThe idle gear is meshed with the balancer drive gear provided on the crankshaft, and the idle gear is slidably supported by the idle shaft and meshes with both the balancer gear and the balancer drive gear. It is possible to move between positions that mesh with only one side.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described based on examples of the present invention shown in the accompanying drawings.
[0009]
1 to 8 show an embodiment of the present invention. FIG. 1 is an overall side view of an engine mounted on a motorcycle, FIG. 2 is a sectional view taken along line 2-2 of FIG. 1, and FIG. 4 is a sectional view taken along the line 4-4 of FIG. 3, FIG. 5 is a sectional view taken along the arrow 5 in FIG. 4, FIG. 6 is a sectional view taken along the line 6-6 in FIG. FIG. 8 is an explanatory view of the operation.
[0010]
As shown in FIG. 1, an in-line four-cylinder engine E supported on a motorcycle body frame 1 by three bolts 2... Has a crankshaft 3 disposed in the left-right direction of the vehicle body and a cylinder axis L.₁Is disposed inclining upward in front of the vehicle body. The casing of the engine E includes an upper casing 4 constituting the upper half of the crankcase, the upper half of the transmission case and the cylinder block, and a lower casing 5 constituting the lower half of the crankcase and the lower half of the transmission case. And a cylinder head 6 coupled to the upper end of the cylinder block of the upper casing 4, a head cover 7 coupled to the upper end of the cylinder head 6, and an oil pan 8 coupled to the lower surface of the lower casing 5.
[0011]
The engine E includes a secondary balancer device for reducing secondary vibration. The secondary balancer device includes a front balancer Bf and a rear balancer Br. The front balancer Bf includes a front balancer shaft 9 disposed below the crankshaft 3 and slightly toward the front of the vehicle body. The rear balancer Br A rear balancer shaft 10 disposed slightly above and rearward of the vehicle body, and an idle shaft 11 disposed below the rear balancer shaft 10. The front balancer shaft 9 and the rear balancer shaft 10 are disposed at substantially symmetrical positions with respect to the crankshaft 3. The transmission housed in the rear part of the upper casing 4 and the lower casing 5 includes a main shaft 12 located behind the crankshaft 3 and a countershaft 13 arranged behind the main shaft 12.
[0012]
As shown in FIGS. 2 and 3, first to fourth cylinders 21 formed in the upper casing 4.₁~ 21₄And the first to fourth pistons 22 respectively.₁~ 22₄Are slidably fitted. The crankshaft 3 has first to fifth journal parts 23.₁~ 23₅And these first to fifth journal parts 23₁~ 23₅First to fourth pin portions 24 provided therebetween₁~ 24₄With. First to fifth journal parts 23₁~ 23₅Are the first to fifth journal support portions 25 formed in the upper casing 4.₁~ 25₅And the first to fifth journal support portions 26 formed in the lower casing 5.₁~ 26₅And the first to fourth pin portions 24 are supported rotatably.₁~ 24₄And the first to fourth pistons 22₁~ 22₄And the first to fourth connecting rod 27₁~ 27₄Connected with.
[0013]
First to fifth journal support portions 26 of the lower casing 5₁~ 26₅And the first to fifth journal support portions 25 of the upper casing 4₁~ 25₅Are integrally coupled by five front casing clamping bolts 14 arranged in front of the crankshaft 3 and five rear casing clamping bolts 15 arranged in the rear of the crankshaft 3. The rigidity is increased by the fastening force at that time.
[0014]
That is, the lower casing 5 that supports the front balancer shaft 9 is made of a steel front casing clamping bolt 14 that has a higher longitudinal elastic modulus (Young's modulus) than the aluminum alloy that is the material of the lower casing 5, and the rear casing. Since the fastening bolts 15 are fastened, the rigidity of the front balancer support portion of the lower casing 5 is increased.
[0015]
Each cylinder 21 has a cylinder head 6.₁~ 21₄Is formed corresponding to the intake port 6 connected to the combustion chamber 28.₁, 6₁And exhaust port 6₂, 6₂Are provided with intake valves 29, 29 and exhaust valves 30, 30. The intake valves 29 and 29 and the exhaust valves 30 and 30 are driven by an intake camshaft 31 and an exhaust camshaft 32 supported on a coupling surface of the cylinder head 6 and a camshaft holder (not shown).
[0016]
A timing chain that houses a drive sprocket 33 provided at the right end of the crankshaft 3 and a timing chain 34 that transmits the rotation of the drive sprocket 33 to the intake camshaft 31 and the exhaust camshaft 32 on the right end surface of the engine E. A chamber 35 is provided, and a part of the opening to the outside is covered with a timing chain chamber cover 36. An AC generator 37 is provided at the left end of the crankshaft 3, and the outer side thereof is covered with an AC generator cover 38.
[0017]
As shown in FIGS. 3 to 5, the third journal portion 23 of the crankshaft 3.₃And the fourth journal part 23₄The third journal support portion 25 formed in the upper casing 4 to support the₃And the fourth journal support section 25₄In the middle, the left and right ends of the idle shaft 11 of the rear balancer Br are constructed. The third journal support portion 25 extends from the rear surface of the cylinder block to the upper surface of the upper casing 4.₃And the fourth journal support section 25₄Is extended outward from the outer wall of the upper casing 4 to provide a casing raised portion 41.
[0018]
The casing raised portion 41 includes a ceiling wall portion 41d covering the upper surface and the rear surface thereof, and the third cylinder 21 connected to the front of the ceiling wall portion 41d.₃Cylinder side wall portion 41e constituting the side wall of the third journal support portion 25.₃The fourth journal support part 25₄The ceiling wall portion 41d and the cylinder side wall portion 41e constitute a highly rigid box structure with only the lower surface opened. The third journal support portion 25 that constitutes the left and right side walls of the casing raised portion 41.₃And the fourth journal support section 25₄The left and right ends of the rear balancer shaft 10 of the rear balancer Br are installed.
[0019]
The rear balancer shaft 10 includes a fourth journal support portion 25.₄A support hole 41b made of a through-hole formed in the third journal support portion 25 and the third journal support portion 25.₃The fourth journal support portion 25 is inserted into the support hole 41a formed of a blind hole from the support hole 41b side.₄It is fixed by the fixing member 42 at the end portion protruding from the outside. As will be described later, the rear balancer shaft 10 is composed of an eccentric shaft, and the phase of the eccentric portion 10b can be adjusted by engaging and rotating a tool in a groove 10a formed at the right end thereof. . The fixing member 42 for fixing the rear balancer shaft 10 so that it cannot rotate and cannot move in the axial direction after the adjustment is completed is formed in a substantially J-shape, and the bolt 43 is formed by sandwiching the right end of the rear balancer shaft 10 in the split groove 42a. After tightening with a bolt 44, the fourth journal support portion 25 of the casing raised portion 41 is secured with a bolt 44.₄Fixed to.
[0020]
The idle shaft 11 has a fourth journal support portion 25.₄A support hole 25b made of a through hole and a third journal support part 25₃The fourth journal support portion 25 is formed in the support hole 25a made of a through hole formed in₄3rd journal support part 25 inserted from the side₃It is fixed by the fixing member 45 and the bolts 46 and 47 at the end portion that passes through. The right end of the idle shaft 11 is a fourth journal support portion 25 with a bolt 48.₄It is positioned in the axial direction by a washer 49 fixed to. The idle shaft 11 is also composed of an eccentric shaft, and the phase of the eccentric portion 11b can be adjusted by engaging and rotating a tool in a groove 11a formed at the right end before the idle shaft 11 is fixed.
[0021]
Fourth journal portion 23 of the crankshaft 3₄A balancer drive gear 51 is integrally formed on the outer periphery of the balancer portion 50 adjacent to the left side of the balancer. Ball bearings 53, 53 are axially positioned on the outer periphery of the eccentric portion 11 b of the idle shaft 11 via a collar 52, and an idle gear 55 that is detachably supported by the ball bearings 53, 53 via a clip 54. Meshes with the balancer drive gear 51.
[0022]
As is clear from FIG. 7, the rear balancer weight 58 is rotatably supported on the outer periphery of the eccentric portion 10 b of the rear balancer shaft 10 via the first needle bearing 56 and the second needle bearing 57. The rear balancer weight 58 includes a weight portion 58a and a cylindrical shaft portion 58b. A rear balancer gear 60 supported on the outer periphery of the cylindrical shaft portion 58b via a plurality of damper rubbers 59 ... meshes with the idle gear 55. To do. The left and right end portions of the rear balancer weight 58 and the third journal support portion 25 of the casing raised portion 41.₃And the fourth journal support section 25₄Between the first thrust washer 61 and the second thrust washer 62, respectively. The weight portion 58a of the rear balancer weight 58 is formed by the third connecting rod 27.₃In order to avoid interference with the large end of the third journal support portion 25 of the casing raised portion 41.₃Is placed adjacent to.
[0023]
Third journal support portion 25 of casing raised portion 41₃The first thrust washer 61 is provided with an annular cylindrical holding portion 61b extending toward the rear balancer weight 58 on the outer periphery of the main body portion 61a, and a third journal on the left side surface of the main body portion 61a. Support part 25₃Thrust washer support surface f₁The thrust force between the left end portion of the rear balancer weight 58 and the retainer 56a of the first needle bearing 56 is supported on the right side surface of the main body portion 61a, and the cylindrical holding portion 61b. Is engaged with the outer peripheral surface of the left end of the rear balancer weight 58, whereby the first thrust washer 61 itself is positioned in the radial direction with respect to the rear balancer weight 58.
[0024]
On the other hand, the fourth journal support portion 25 of the casing raised portion 41.₄The second thrust washer 62 is provided with an annular cylindrical holding portion 62b extending toward the rear balancer weight 58 on the inner periphery of the main body portion 62a. Journal support section 25₄Thrust washer support surface f₂And the thrust force between the right end of the rear balancer weight 58 and the right end of the rear balancer gear 60 on the left side surface of the main body 62a, and the left end surface of the cylindrical holding portion 62b. The thrust force between the second needle bearing 57 and the retainer 57a is supported, and the outer peripheral surface of the cylindrical holding portion 62b is engaged with the inner peripheral surface of the right end of the rear balancer weight 58, whereby the second thrust washer 62 itself Is positioned with respect to the rear balancer weight 58 in the radial direction.
[0025]
As is apparent from the comparison of the shapes of the first thrust washer 61 and the second thrust washer 62, the cylindrical holding portion 61b is formed by forming the cylindrical holding portion 61b of the first thrust washer 61 on the outer periphery of the main body portion 61a. The first needle bearing 56 can be moved toward the main body 61a without interfering with the main body 61a. As a result, the axial center line A of the first needle bearing 56 is brought close to the center line B passing through the center of gravity of the weight portion 58a of the rear balancer weight 58, and the offset amount α between the center lines A and B is minimized. Can be suppressed. As a result, the unbalanced load acting on the first needle bearing 56 is reduced, so that the first needle bearing 56 having a small capacity can be used, and the durability can be improved.
[0026]
When the rear balancer weight 58 is assembled in the casing raised portion 41, the rear balancer weight 58, the rear balancer gear 60, the damper rubber 59, etc., the first needle bearing 56, the second needle bearing 57, the first thrust washer 61 and the second The sub-assembly of the thrust washer 62 is assembled together. In the state where the subassembly is assembled at the regular assembly position shown in FIG. 4, the first thrust washer 61 and the second thrust washer 62 are connected to the third journal support portion 25 of the casing raised portion 41.₃And the fourth journal support section 25₄To prevent it from falling off. However, while the sub-assembly is inserted from the opening of the upper casing 4 to the regular assembly position, as shown in FIG.₃And the fourth journal support section 25₄Distance D between opposite faces₁Is a third journal support portion 25 in the regular assembly position for weight reduction.₃And 4th journal support section 25₄Distance D between₂(F₁, F₂Since the first thrust washer 61 and the second thrust washer 62 are likely to fall off the rear balancer weight 58, there is a problem that workability is lowered. In particular, since the subassembly is assembled to the deepest part of the casing raised portion 41, the operator's hand is difficult to enter and the operation is difficult.
[0027]
Therefore, in this embodiment, as shown in FIGS. 3, 4 and 6, the third journal support portion 25 is used.₃And the fourth journal support section 25₄The thrust washer support surface f from the opening of the upper casing 4 to the opposite surface of₁, F₂Thrust washer guide surface f₃, F₄Is projected. Left thrust washer support surface f₁And slide guide surface f₃Are formed flush and the right thrust washer support surface f₂And thrust washer guide surface f₄Are formed flush with each other, so that a pair of opposing thrust washer support surfaces f₁, F₂The distance between and a pair of opposing thrust guide surfaces f₃, F₄The distance between them is D₂Is equal to
[0028]
Thus, when the sub-assembly of the rear balancer weight 58 is inserted into the assembly position in the casing raised portion 41, a pair of thrust washer guide surfaces f starting from the opening of the upper casing 4 is obtained.₃, F₄While the first thrust washer 61 and the second thrust washer 62 at both ends of the subassembly are in contact with each other, the subassembly is inserted into the assembly position in the casing raised portion 41 while sliding. Thus, the first thrust washer 61 and the second thrust washer 62 are not dropped from the rear balancer weight 58, and the left and right thrust washer support surfaces f₁, F₂As a result, the assembling workability is greatly improved.
[0029]
As is apparent from FIGS. 3 to 6, an arc-shaped rib 63 protrudes from the bottom of the casing raised portion 41, and the fourth journal support portion 25 can be seen from the rib 63.₄A circular opening 41c that can be closed by a plug 64 (see FIG. 4) is formed. A part of the rear balancer gear 60 and the phase alignment mark 63a of the rib 63 can be visually confirmed through the opening 41c, and the phase alignment mark engraved on one tooth by rotating the rear balancer gear 60 by inserting a finger from the opening 41c. By making the mark 60a (see FIG. 5) face the phase alignment mark 63a of the rib 63, the phase of the rear balancer gear 60 can be adjusted when the rear balancer Br described later is assembled.
[0030]
Further, when the subassembly is inserted into the casing raised portion 41, the rear balancer gear 60 is abutted against the rib 63 and positioned roughly as shown in FIGS. It is prevented from falling off at the bottom of the part 41, and the assembling work becomes easy.
[0031]
As shown in FIGS. 3 and 4, the front balancer shaft 9 of the front balancer Bf is connected to the third journal support portion 26 of the lower casing 5.₃And the fourth journal support section 26₄And a first balance bearing 67 having a first needle bearing 65, a second needle bearing 66, a weight portion 67a and a cylindrical shaft portion 67b, and a first thrust washer 68. The second thrust washer 69 and the front balancer gear 71 that meshes with the damper rubber 70 and the balancer drive gear 51 are supported. The front balancer shaft 9 is fixed to the lower casing 5 by a fixing member 72 and bolts 73 and 74.
[0032]
As apparent from FIG. 4, the front balancer Bf has a structure symmetrical to the rear balancer Br with respect to the crankshaft 3 except that members corresponding to the idle shaft 11 and the idle gear 55 are not provided. The description of the overlapping structure is omitted. However, since the front balancer Bf is disposed at a relatively shallow position from the opening of the lower casing 5 and does not have a member corresponding to the idle gear 55, it can be easily assembled and phased. Br thrust washer guide surface f₃, F₄The thing corresponding to these, or the thing equivalent to the rib 63 is unnecessary.
[0033]
In FIG. 4, since the cylindrical holding portion 68b of the first thrust washer 68 of the front balancer Bf is formed on the outer periphery of the main body portion 68a, the first needle bearing 65 is moved to the main body portion without interfering with the cylindrical holding portion 68b. The center line of the first needle bearing 65 can be moved closer to the center line of the weight portion 67a of the front balancer weight 67. As a result, similarly to the above-described rear balancer Br, it is possible to reduce a load caused by an unbalanced load acting on the first needle bearing 65 of the front balancer Bf.
[0034]
Thus, the number of teeth of the rear balancer gear 60 and the number of teeth of the front balancer gear 71 are both set to one half of the number of teeth of the balancer drive gear 51 provided on the crankshaft 3. The rear balancer gear 60 rotates in the same direction as the crankshaft 3 at twice the rotational speed of the crankshaft 3, and the front balancer gear 71 rotates in the opposite direction to the crankshaft 3 at twice the rotational speed of the crankshaft 3. Rotates and reduces secondary vibrations of engine E as is well known.
[0035]
In FIG. 3, in order to effectively reduce the vibration of the engine E, it is desirable that the front balancer shaft 9 and the rear balancer shaft 10 are arranged symmetrically about the crankshaft 3. Cylinder axis L₁And the distance between the front balancer shaft 9 and d₁Cylinder axis L₁And the distance between the rear balancer shaft 10 and d₂Cylinder axis L of the front balancer shaft 9 and the rear balancer shaft 10₁The distance in the direction along₃Then the distance d₁And distance d₂Are set equal and the distance d₃Connecting rod 27₁~ 27₄It is desirable to set it to be approximately equal to the length of.
[0036]
By arranging the front balancer shaft 9 at the front lower side of the crankshaft 3 and the rear balancer shaft 10 at the rear upper side of the crankshaft 3, the above condition can be satisfied relatively easily. Inclined cylinder 21₁~ 21₄Since the rear balancer shaft 10 is used as a space for arranging various auxiliary devices (for example, the air cleaner 16 and the fuel tank 17 shown in FIG. 1), the rear balancer shaft 10 may interfere with the auxiliary devices. However, in this embodiment, the minimum casing raised portion 41 is provided on the upper surface of the upper casing 4 and the rear balancer shaft 10 is accommodated therein.₁~ 21₄It is possible to avoid the interference with auxiliary devices by maximizing the space behind. In addition, the idle shaft 11 is disposed not behind the rear balancer shaft 10 but behind the cylinder 21.₁~ 21₄It becomes possible to secure a larger space behind the rear.
[0037]
As is apparent from FIG. 4, the third journal portion 23 of the crankshaft 3₃And the fourth journal part 23₄The third journal support portion 25 of the upper casing 4 for supporting₃And the fourth journal support section 25₄The rear balancer shaft 10 is supported by the third journal portion 23.₃And the fourth journal part 23₄3rd journal support part 26 of the lower casing 5 which supports₃And the fourth journal support section 26₄The front balancer shaft 9 is supported on the front. If the balancer shafts 9 and 10 are supported on the outer walls of the casings 4 and 5, the casings 4 and 5 need to be reinforced to counteract the centrifugal force acting on the balancer shafts 9 and 10 and the weight increases. As in this embodiment, the journal support portion 25 having high rigidity to support the crankshaft 3 is used.₃, 25₄, 26₃, 26₄If the balancer shafts 9 and 10 are supported using the above, reinforcement of the casings 4 and 5 becomes unnecessary and the weight is reduced.
[0038]
In particular, the journal support 25 of the upper casing 4₁~ 25₅And journal support 26 of the lower casing 5₁~ 26₅The coupling rigidity is enhanced by the fastening force of the steel front fastening bolts 14 and the rear fastening bolts 15 having a higher longitudinal elastic modulus (Young's modulus) than the aluminum alloy that is the material of the upper casing 4. Therefore, the support rigidity of the front balancer shaft 9 and the rear balancer shaft 10 supported thereby is also improved. Thereby, the vibration generating force of the front balancer shaft 9 and the rear balancer shaft 10 (vibration suppression force for suppressing the vibration of the crankshaft 9) acts effectively, and the vibration of the entire engine E can be minimized. In particular, the rear balancer shaft 10 is supported by a casing raised portion 41 having a box structure in which only the lower surface is opened, and the rear balancer support portion is located in the vicinity of the fastening portion of the rear fastening bolts 15. Can be ensured.
[0039]
Next, the assembly of the rear balancer Br and the front balancer Bf having the above-described structure and the removal of the backlash will be described.
[0040]
The rear balancer Br is assembled in a state where the upper casing 4 is fixed with its opening facing upward, the rear balancer weight 58, the rear balancer gear 60, the damper rubber 59,..., The first needle bearing 56, the second needle bearing 57, The subassembly in which the first thrust washer 61 and the second thrust washer 62 are temporarily assembled is moved from the opening of the upper casing 4 to the first washer 61 and the second thrust washer 62 through the thrust washer guide surface f as described above.₃, F₄It is inserted into the casing raised portion 41 while being guided by the guide. Subsequently, the tip of the rear balancer shaft 10 is connected to the fourth journal support portion 25 of the casing raised portion 41.₄The third journal support portion 25 is inserted through the support hole 41b and penetrates through the inside of the subassembly.₃To the support hole 41a.
[0041]
Next, an idle gear 55 having ball bearings 53 and 53 preliminarily assembled on the inner periphery is inserted from the opening of the upper casing 4 and meshed with the rear balancer gear 60. Fourth journal support section 25₄The ball bearings 53 and 53 and the collar 52 are inserted through the support holes 25b. At this time, the idle gear 55 is retracted to a position indicated by a chain line in FIG. When the idle gear 55 is in the retracted position, the meshing relationship between the idle gear 55 and the rear balancer gear 60 is maintained.
[0042]
Next, a finger is inserted through the opening 41 c of the casing raised portion 41 to rotate the rear balancer gear 60, so that the phase alignment mark 60 a faces the phase alignment mark 63 a of the rib 63. In this state, the journal support portion 25 of the upper casing 4₁~ 25₅The journal 23 of the crankshaft 3₁~ 23₅However, since the idle gear 55 is retracted to the chain line position as described above, the balancer drive gear 51 of the crankshaft 3 does not mesh with the idle gear 55. Subsequently, the crankshaft 3 is rotated, for example, the first pin portion 24.₁And the fourth pin portion 24₄Is positioned at the top dead center position. From this state, the idle gear 55 is slid to the solid line position in FIG. 4 and meshed with the balancer drive gear 51, and then the idle shaft 11 is locked in the support hole 25a.
[0043]
With the above procedure, the rear balancer gear 60 can be assembled so that the rear balancer gear 60 has a predetermined phase with respect to the phase of the crankshaft 3.
[0044]
The front balancer Bf is assembled by assembling the front balancer shaft 9 and the front balancer weight 67 to the lower casing 5 and temporarily fixing the front balancer gear 71 so as to have a predetermined phase, so that the crankshaft 3 has a predetermined phase. The lower casing 5 may be coupled to the upper casing 4 temporarily fixed as described above. The front balancer Bf can be easily assembled because the front balancer Bf is disposed at a shallow position from the opening of the lower casing 5.
[0045]
The backlash adjustment of the rear balancer Br is performed by adjusting the rotational positions of the rear balancer shaft 10 and the idle shaft 11 made of an eccentric shaft. As shown in FIG. 8 (A), the third journal support portion 25 of the casing raised portion 41.₃And the fourth journal support section 25₄The axis P 'of the eccentric portion 10b that supports the first needle bearing 56 and the second needle bearing 57 is eccentric by a distance β with respect to the axis P of both ends of the rear balancer shaft 10 supported by the upper balance. 4th third journal section 25₃And the fourth journal part 25₄The axis Q ′ of the eccentric portion 11b that supports the idle gear 55 is eccentric by a distance γ with respect to the axis Q of both ends of the idle shaft 11 supported by the shaft. If the axis O of the crankshaft 3 is assumed, the angle θ formed by the line segment QO and the line segment QP is set to approximately 90 °.
[0046]
First, as shown in FIG. 8 (A), the eccentric portion 10b (shaded portion) of the rear balancer shaft 10 is eccentrically fixed to an arrow a substantially parallel to the direction of the line segment QP and temporarily fixed. 11 eccentric portions 11b (shaded portions) are eccentrically fixed in the direction of the arrow b substantially parallel to the direction of the line segment OQ and temporarily fixed. At this time, the meshing between the rear balancer gear 60 and the idle gear 55 is loose, and the meshing between the idle gear 55 and the balancer driving gear 51 is also loose.
[0047]
From this state, when the idle shaft 11 is rotated and fixed in the direction c in FIG. 8A by a predetermined angle (for example, about 120 °), the axis Q ′ of the eccentric portion 11 b of the idle shaft 11 approaches the crankshaft 3. 8B, the backlash between the balancer drive gear 51 and the idle gear 55 is adjusted to an appropriate size. At this time, the distance between the idle gear 55 and the rear balancer gear 60 is slightly reduced, but the meshing between the idle gear 55 and the rear balancer gear 60 is maintained in a loose state. Can be moved smoothly.
[0048]
When the backlash between the balancer drive gear 51 and the idle gear 55 is adjusted as described above, the rear balancer shaft 10 is subsequently rotated by a predetermined angle (for example, about 90 °) in the direction of arrow d in FIG. And fix. As a result, the rear balancer gear 60 moves in the direction of arrow f in FIG. 8B, and the backlash between the rear balancer gear 60 and the idle gear 55 is adjusted to an appropriate size. At this time, since the distance between the idle gear 55 and the rear balancer gear 60 is slightly reduced in the previous process, the amount of movement of the rear balancer gear 60 in the direction of the arrow f can be reduced accordingly. Of course, the backlash between the already adjusted balancer drive gear 51 and the idle gear 55 is not affected by the movement of the rear balancer gear 60 in the direction of the arrow f.
[0049]
Adjustment of the backlash of the front balancer Bf can be easily performed only by rotating the front balancer shaft 9 provided with the eccentric portion 9b. That is, the third journal portion 26 of the lower casing 5₃And the fourth journal part 26₄Since the axis of the eccentric portion 9b supporting the front balancer gear 71 is eccentric by a predetermined distance with respect to the axis of both ends of the front balancer shaft 9 supported by the front balancer shaft 9, when the front balancer shaft 9 is rotated, the front balancer gear The backlash is adjusted as 71 approaches / separates from the balancer drive gear 51 of the crankshaft 3.
[0050]
As mentioned above, although the Example of this invention was explained in full detail, this invention can perform a various design change in the range which does not deviate from the summary.
[0051]
For example, although the present invention is applied to the rear balancer Br in the embodiment, it can also be applied to the front balancer Bf. Moreover, although the secondary balancer apparatus was illustrated in the Example, this invention is applicable also to a primary balancer apparatus.
[0052]
【The invention's effect】
As described above, according to the first aspect of the present invention, the phase alignment mark for performing phase alignment of the balancer gear at the time of assembly is provided so as to face the outer periphery of the balancer gear. Since the opposing portions of the gear and the phase alignment mark are visible from the opening formed in the casing, it is possible to easily perform phase alignment of the balancer gear assembled inside the casing, and the assembly workability is improved. .In addition, ribs formed with phase alignment marks project from the inner wall of the casing, and the balancer gear inserted into the assembly position in the casing at the time of assembly is brought into contact with the rib for positioning, so that the assembly workability is improved. .
[0054]
And claims2According to the invention described inA phase alignment mark for phase adjustment of the balancer gear during assembly is provided so as to face the outer periphery of the balancer gear, and the opposite part of the balancer gear and phase alignment mark is visible from the opening formed in the casing. Therefore, the phase of the balancer gear assembled in the casing can be easily adjusted, and the assembly workability is improved. MoreoverAn idle gear interposed between the balancer gear and the balancer drive gear can move along the idle shaft between a position meshing with both the balancer gear and the balancer drive gear and a position meshing with either of them. Therefore, with the balancer gear and balancer drive gear phase determined independently, the balancer gear phase can be adjusted simply by sliding the idle gear and meshing with both the balancer gear and the balancer drive gear. Can be achieved.
[Brief description of the drawings]
FIG. 1 is an overall side view of an engine mounted on a motorcycle.
2 is a sectional view taken along line 2-2 of FIG.
3 is a sectional view taken along line 3-3 in FIG.
4 is a sectional view taken along line 4-4 of FIG.
5 is a view in the direction of arrow 5 in FIG.
6 is a cross-sectional view taken along line 6-6 of FIG.
7 is an enlarged view of the main part of FIG.
FIG. 8 is an explanatory diagram of the action.
[Explanation of symbols]
3 Crankshaft
4 Upper casing (casing)
10 Rear balancer shaft (balancer shaft)
11 Idle shaft
41c opening
51 Balancer drive gear
55 Idle Gear
58 Rear balancer weight (balancer weight)
60 Rear balancer gear (balancer gear)
63 Ribs
63a Phase alignment mark

Claims (2)

A balancer weight (58) integrally having a balancer gear (60) is rotatably supported on a balancer shaft (10) installed inside the casing (4), and the balancer gear (60) is connected to the crankshaft (3). In addition , a phase alignment mark (63a) for phase alignment of the balancer gear (60) at the time of assembly is provided so as to face the outer periphery of the balancer gear (60), and the balancer gear (60) and the phase alignment mark In the balancer device for the engine, in which the opening (41c) that makes the opposite portion of (63a) visible from the outside is formed in the casing (4) ,
An engine balancer characterized in that a rib (63) provided with the phase alignment mark (63a) is provided on the inner wall of the casing (4) so that the balancer gear (60) is brought into contact with and positioned when assembled. apparatus. A balancer weight (58) integrally having a balancer gear (60) is rotatably supported on a balancer shaft (10) installed inside the casing (4), and the balancer gear (60) is connected to the crankshaft (3). In addition, a phase alignment mark (63a) for phase alignment of the balancer gear (60) at the time of assembly is provided so as to face the outer periphery of the balancer gear (60), and the balancer gear (60) and the phase alignment mark In the balancer device for the engine, in which the opening (41c) that makes the opposite portion of (63a) visible from the outside is formed in the casing (4),
The balancer gear (60) is meshed with the idle gear (55) provided on the idle shaft (11), and the idle gear (55) is meshed with the balancer drive gear (51) provided on the crankshaft (3). The idle gear (55) is slidably supported by the idle shaft (11), and is between a position where it meshes with both the balancer gear (60) and the balancer drive gear (51) and a position where it meshes with only one of them. balancer device characteristics and to Rue engine that is movable.

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