JPH02217643A - Balancer shaft driving device of internal combustion engine - Google Patents

Abstract

PURPOSE:To facilitate phase alignment by putting the locational index in alignment with the before-setting checking index in the condition that a balancer shaft is fixed, and putting the first named index identical to the after-setting checking index when case member is installed on the engine body. CONSTITUTION:When a gear case 42 is to be mounted to a cylinder block 1, a rod-shaped member 94 is inserted in a through hole 92 and No.1 balancer shaft 21 is fixed, and in this condition, the locational index M1 is put in alignment with the before-setting checking index M3, and fastening is made with bolt together with a pump case. At this time, a helical driving gear on a reverse rotation driving pulley 37 will begin meshing with a driven gear no No.1 balancer shaft 21 under the condition that the two indeces M1, M3 are identical, and the driving gear rotates in accordance with fastening, and when meshing is made fully, the locational index M1 rotates till the after setting checking index M2, and the relative phase of the reverse rotation driving pulley 37 with No.1 balancer shaft 21 will become a preset phase. Thus phase alignment of the balancer shaft with the reverse rotation driving pulley can be performed easily.

Description

Detailed Description of the Invention A1 Objective of the Invention (1) Industrial Application Field The present invention is directed to a balancer shaft having an eccentric weight portion rotatably supported by an engine body, and a case member attached to the engine body. A rotating shaft is rotatably supported parallel to the balancer shaft, a driving gear provided at the inner end of the rotating shaft and a driven gear fixed to one end of the balancer shaft are meshed, and the rotating shaft projects from the case member. The present invention relates to a balancer shaft drive device for an internal combustion engine in which a rotating shaft is interlocked and connected to a crankshaft via a wrap-around transmission system including a driven wheel for reverse drive fixed to the outer end of the rotary shaft.

(2) Prior art Conventionally, such a device has been used, for example, in U.S. Pat.
It is publicly known from the publication No.

(3) Problems to be Solved by the Invention In the above conventional system, a spur gear is used as a driving gear and a driven gear, but it is possible to improve the engagement ratio of the gears, reduce the size, and reduce vibration due to smooth rotation. It is desirable to use helical gears to reduce noise. By the way, the balancer shaft needs to be supported in the engine body with a constant phase with respect to the crankshaft, so when attaching the case member supporting the rotating shaft, which has a driven wheel for reverse drive and a drive gear at both ends, to the engine body, It is necessary to maintain a constant phase relationship between the reverse drive driven wheel and the balancer shaft, and if both gears are spur gears, the drive gear and driven gear should be meshed with the balancer shaft fixed. By attaching the case member to the engine body, the phase relationship between the reverse drive driven wheel and the balancer shaft can be maintained constant. However, when the driving gear and the driven gear are helical gears, the installation of the case member to the engine body is sometimes difficult at the time when the driving gear starts meshing with the driven gear and when the meshing ends. The phase relationship between the axes differs, and the task of aligning the phases of the reverse drive driven wheel and the balancer shaft becomes complicated.

The present invention has been made in view of the above circumstances, and uses helical gears as the drive gear and wave gear to reduce the size, vibration and noise, and to facilitate phase alignment between the balancer shaft and the driven wheels for reverse drive. An object of the present invention is to provide a balancer shaft drive device for an internal combustion engine.

B9 Structure of the Invention (1) Means for Solving the Problems According to the present invention, the driving gear and the driven gear are helical gears, and a positioning index is provided on the outer surface of the driven wheel for reverse drive, and the positioning index is provided on the outer surface of the driven wheel for reverse drive. On the outer surface, there is a post-setting confirmation indicator that corresponds to the positioning indicator when the balancer shaft and reverse drive driven wheel reach the set phase when the driving gear is fully engaged with the driven gear, and the driven gear is fixed. deviation in the circumferential direction from the post-setting confirmation index by an amount corresponding to the angular displacement of the driven wheel for reverse drive in accordance with moving the drive gear in the axial direction from the meshing completion position to the meshing start position with the driven gear in the state A pre-set confirmation indicator for the position set is provided at a portion removed from the reverse drive driven wheel.

(2) Effect According to the above configuration, sometimes the case member is attached to the engine body by aligning the positioning index and the pre-setting confirmation index with the balancer shaft fixed, and then attaching the case member to the engine body. By matching the positioning index and the post-setting confirmation index at the end of the installation, when installing the case member to the engine body, the driven wheel for reverse drive and the balancer shaft can be in the set phase. Attachment allows the circumferential position of the front driven wheel for reverse rotation to be easily determined.

(3) Example Hereinafter, an example in which the present invention is applied to a balancer shaft drive device of a DOHC type in-line four-cylinder internal combustion engine will be explained with reference to the drawings. In Fig. 4, the engine body E is composed of a cylinder head 2 coupled to the upper part of a cylinder block 1, an oil pan 3 coupled to the lower part of the cylinder block L, and a head cover 4 coupled to the upper part of the cylinder head 2. be done.

The cylinder block 1 includes an upper cylinder barrel portion 1a and a lower crankcase portion 1b, and is made of aluminum alloy. In the cylinder barrel part 1a,
Four cylinder bores 5 arranged in series are provided, and a piston 6 is slidably fitted into each cylinder bore 5. Also, crank case part 1
b, a plurality of journal bearings 7 are spaced apart along the arrangement direction of each cylinder bore 5, and bearing caps 8 are respectively fixed to the lower surface of each journal bearing 7. The crankshaft 9 is rotatably supported by the journal bearings 7, and the crank pins 9a of the crankshaft 9, and the pistons 6,...
and are connected via connecting rods 10... Further, each of the bearing caps 8 . . . is integrally coupled by a bridge member 11.

At one end of the crankshaft 9 in the axial direction, an oil pump 12 driven by the crankshaft 9 is disposed on the outer side wall 1c of the cylinder block I. This oil pump 12 includes a rotor 14 fixed to a crankshaft 9 within a pump case 13 attached to the side wall outer surface 1c of the cylinder block l.
An oil strainer 17 is connected to a suction port 15 provided in the pump case 13 via a suction pipe 16. Further, a discharge port 18 provided in the pump case 13 is connected to a lubricating oil passage 19 bored in the cylinder block l parallel to the crankshaft 9. The other axial end of the crankshaft 9 projects slightly from the other end side wall of the cylinder block 1, and a transmission is connected to the other end of the crankshaft 9 via a clutch (not shown).

5 and 6, a first balancer shaft 21 and a second balancer shaft 22 are located above the crankshaft 9 at substantially symmetrical positions with respect to a vertical plane passing through the axis of the crankshaft 9. It is arranged parallel to the crankshaft 9 and rotatable. These balancer shafts 21 and 22 suppress secondary vibrations of the engine, and are inserted into the cylinder block 1 with one axial end protruding from the side wall outer surface IC of the cylinder block 1. Both balancer shafts 21 and 22 have eccentric weight portions 21a and 21b; 22a and 22b spaced apart from each other near the other end in the axial direction, and the cylinder block 1 includes a first Balancer shaft 21
A pair of bearing holes 23. which support a portion near the other end in the axial direction.
24 is provided, and a pair of bearing holes 25 and 26 for supporting a portion of the second balancer shaft 22 near the other end in the axial direction and a pair of bearing holes 27 for supporting a portion of the second balancer shaft 22 near the one end in the axial direction are provided. It will be done.

One end of the crankshaft 9 protrudes from the pump case 13 of the oil pump 12, and the first drive pulley 28 of the first winding transmission system T1 is attached to the protruding end of the crankshaft 9.
is fixed, and the second drive pulley z9 of the second winding transmission system T2 is fixed to the side farther from the cylinder block l than the first drive pulley 28, and both drive pulleys l728,
29 is rotationally driven in the direction shown by the arrow in FIG.

The first winding transmission system TI connects an intake side valve train camshaft 30 rotatably supported by the cylinder head 2 parallel to the crankshaft 9 to drive the intake side valve train, and an exhaust side valve train mechanism. The cylinder head 2 is parallel to the crankshaft 9 for driving.
This is a timing transmission system for driving an exhaust side valve drive camshaft 31 which is rotatably supported by
The driving pulley 28, the camshaft driving driven bools IJ33 and 34 fixed to both camshafts 30 and 31, respectively, the water pump driving driven boob 935 fixed to the pump shaft 32a of the water pump 32, and each pulley 2B. ,33,3
4.35, and a first timing belt 36 which is wound around the timing belt 36.

The second winding transmission system T2 includes first and second balancer shafts 21
．． 22, which includes a second drive pulley 29, a reverse drive driven pulley 37 as a reverse drive driven wheel that is interlocked and connected to the first balancer shaft 21, and a second
A driven pulley 38 for forward rotation drive provided on the balancer shaft 22
and an endless second wheel suspended from each pulley 29.37.38.
It is composed of a timing belt 39.

Referring to FIGS. 7 and 8 together, a gear case 42 serving as a case member that covers a part of the pump case 13 is attached to the pump case 13 at a portion corresponding to the first balancer shaft 21. That is, the gear case 42 is
It is attached to the cylinder block 1 together with the pump case 13 by bolts 43. Said reverse drive driven pulley 3
7 is a gear case 42 parallel to the first balancer shaft 21.
It is fixed to the protruding end of a rotating shaft 44 which is rotatably supported by the rotary shaft 44 . Moreover, one end portion of the first balancer shaft 21 is thrust into the gear case 42 while being rotatably supported by the pump case 13 . That is, the pump case 13 is provided with a bearing hole 13a that rotatably supports one end of the first balancer shaft 21, and the first balancer shaft is inserted between the pump case 13 and the gear case 42 from the bearing hole 13a. 21
One end of the is inserted.

A driven gear 41, which is a helical gear, is located at the end of the first balancer shaft 21 between the pump case 13 and the gear case 42.
is fixed to the rotating shaft 44, and a driving gear 40, which is a helical gear, is integrally provided at the inner end of the rotating shaft 44. Moreover, both gears are 40.
41 are meshed with each other, and the power from the reverse drive driven pulley 37 is transmitted to the first balancer shaft 21 via gears 40 and 41 that mesh with each other. That is, both balancer shafts 21, 22 are driven to rotate in opposite directions.

Further, the tooth width Dl along the axial direction of the driving gear 40 is the same as that of the driven gear 4.
The tooth width D2 along the axial direction of the driven gear 4 is set to be greater than the value required for the power generated by meshing with the driven gear 4.
It is set larger than i.

Moreover, the tooth width D2 is set so that there are margin widths D2a and D2b on both sides of the tooth width corresponding to the tooth width D1.

In FIG. 9, a positioning index Ml is provided on the outer surface of the reverse drive driven pulley 37 near the outer periphery by, for example, punching, and the outer surface of the gear case 42 is covered with the reverse drive driven pulley 37. For example, by punching, etc., the post-setting confirmation indicator M2 and the pre-setting confirmation indicator M3 are placed at a position that can correspond to the positioning indicator Ml in the part that is not covered, and the post-setting confirmation indicator M2 and the pre-setting confirmation indicator M3 are spaced apart in the circumferential direction of the reverse drive driven pulley 37. provided.

The confirmation index M2 after setting is the driven gear 41 of the drive gear 40.
When the phase between the first balancer shaft 21 and the driven pulley 37 for reverse rotation reaches a preset phase in the fully engaged state (the state shown in FIGS. 7 and 8), it corresponds to the positioning index Ml. The pre-setting confirmation indicator M3 is provided at a position where the driven gear 41 is fixed.
The reverse drive driven boot I is moved in the axial direction from the engagement completion position to the engagement start position with the driven gear 41.
737 is provided at a position shifted in the circumferential direction from the post-setting confirmation mark M2 by an amount corresponding to the angular displacement. Moreover, both confirmation indicators M2. M3 is a driven pulley for reverse drive 37, which is designed to facilitate correspondence with the positioning index M1 when viewed from the outside in the axial direction of the driven pulley 37 for reverse drive. They are respectively provided at the tips of arcuate protrusions 42a provided on gear case 42 so as to partially surround the periphery of J37.

In FIG. 10, a through hole 92 extending in a direction perpendicular to the axis of the balancer shaft 21 is provided in a portion near one end of the first balancer shaft 21. As shown in FIG. The through hole 92 is bored at a position offset from the axis of the first balancer shaft 21, and the first balancer shaft 21 has a hole protruding outward in the radial direction on one diameter line of the first balancer shaft 21 to maintain balance. A pair of raised parts 21
c, 2Id are provided, and a through hole 9 is provided in one raised portion 21c.
2 is drilled.

Further, an insertion hole 93 having the same diameter as the through hole 92 is formed in the cylinder block 1 at a portion corresponding to the through hole 92 and opens on the outer surface of the cylinder block 1 .

When assembling the gear case 42, a rod-shaped member 94 such as a screwdriver is sometimes inserted from the insertion hole 93 into the through-hole 92, whereby the first balancer shaft 21 can be temporarily fixed.

Referring also to FIG. 11, above the crankshaft 9, a support shaft 45 parallel to the crankshaft 9 is implanted in the cylinder block 1. The support shaft 45 has a large diameter threaded portion 45a on the base end side and a male threaded thread 45 having a smaller diameter than the large diameter threaded portion 45a.
A shaft portion 45b having a tip end thereof is coaxially connected via a flange portion 45d, and the flange portion 4
The large diameter threaded portion 4 is in contact with the outer surface Ic of the 5di side wall.
It is implanted in the cylinder block 1 by screwing together the parts 5a.

A first tensioner 46 for adjusting the tension of the first timing heald 36 in the first winding transmission system Tl is supported on the support shaft 45, and on the axially outer side of the first tensioner 46, The second in the first winding transmission system Tl
A second tensioner 47 for adjusting the tension of the timing belt 39 is supported.

12 and 13, the first tensioner 46
is composed of a plurality of balls 50 interposed between an inner ring 48 supported by a shaft portion 45b of a support shaft 45 and an outer ring 49 in sliding contact with the outer surface of the first timing belt 36,
A ring-shaped support member 51 press-fitted onto the outer surface of the proximal end of the inner ring 4 has a pair of protrusions 51a and 51b protruding outward along a diameter line. One protrusion 51a has a support hole 5.
2 is bored, and a shaft 53 that passes through the support hole 52 and is fixed to the Ginonda Block I allows the first tenso yoner 4 to be
6 is swingably supported. An arcuate long hole 54 centered on the shaft 53 is bored in the inner ring 4, and the shaft portion 45b of the support shaft 45 is inserted into the long hole 54. Further, in addition to the first tension spring 55 whose one end is engaged with the cylinder block 1, ◇;i is engaged with the other protrusion 51b, and the spring force of the first tension spring 55 causes the first
The outer ring 49 of the tensioner 46 is connected to the first timing heald 3.
6 from the outside, thereby applying a certain tension to the first timing heald 36.

The second tensioner 47 has a plurality of balls 5 between an inner ring 56 and an outer ring 58 that is in sliding contact with the second timing belt 39.
7 is interposed. Further, one end of a tension arm 59 which is rotatably supported by a shaft 60 fixed to the cylinder block 1 parallel to the crankshaft 9 is connected to the inner ring 56.
is fixed to.

Furthermore, an arc-shaped elongated hole 61 centered on the shaft 60 is bored in the center of the inner ring 56, and the shaft portion 45b of the support shaft 45 is inserted into the elongated hole 61. Furthermore, a second tension spring 62 is stretched between the other end of the tension arm 59 and the cylinder block 1, and the spring force of the second tension spring 62 causes the outer ring 58 to be applied to the second timing heald 39 from the outside. The second timing belt 39 is pressed against the second timing belt 39, thereby applying a certain tension to the second timing belt 39. In this second tensioner 47, the width of the outer ring 58 is the same as that of the first tensioner 4.
The width is set smaller than the width of the outer ring 49 in No. 6.

Thus, the first timing belt 36 in the first winding transmission system T1 connects the slack side between the first drive pulley 28 and the water pump driving driven boob 1135 to the first tensioner 4.
By being pressed from the outside toward the inside at 6, the gear case 42 is curved deeply inward, and the gear case 42 is disposed in the empty space created by the curve. Moreover, the first
The angle α between the direction in which the first timing belt 36 is pressed by the tensioner 46 and the direction in which the second timing belt 39 is pressed by the second tensioner 47 is set to 90 degrees or more, preferably 120 degrees or more, for example 130 degrees.

The first winding transmission system T1 and the second winding transmission system T2 are covered by a side cover 65, and the support shaft 45
The distal end thereof passes through the side cover 65 and projects outward. Moreover, a nut 66 that is screwed onto the male threaded portion 45c at the tip of the support shaft 45 and comes into contact with the inner ring end surface of the second tensioner 47 is rotatably engaged with the side cover 65.
The Nando 66 can be rotated from outside the side cover 65. Then, by tightening the NAND 66, the first
The inner rings 48.degree. 56 of the second tensioners 46, 47 are movable relative to each other in a plane perpendicular to the axis of the support shaft 45 and abut against each other.

A rotating ring 67 that protrudes outward from the side cover 65 is fixed to the crankshaft 9, and a third drive pulley 68 of the third winding transmission system T3 is attached to the axially inner side of the rotating ring 67. and the fourth winding transmission system T4
A fourth drive pulley 69 is integrally provided on the axially outer side.

The third winding transmission system T3 is a transmission system for driving the AC generator 70 and air conditioner compressor 71 attached to the cylinder block 1, and is fixed to the third drive pulley 68 and the AC generator 700 human power shaft. A driven pulley 72 for driving an AC generator, a driven pulley 73 for driving a compressor fixed to the input shaft of a compressor 71 for an air conditioner, and each pulley 6B, 72.7.
3 and an endless belt 74 suspended around the belt 3. The fourth winding transmission system T4 is a transmission system for driving the power steering hydraulic pump 75 attached to the cylinder head 2, and is fixed to the fourth drive pulley 69 and the human power shaft of the hydraulic pump 75. It is composed of a hydraulic pump driving driven boob IJ76 and an endless belt 77 suspended by both pulleys 69 and 76.

Next, to explain the configuration of the lubrication oil supply system, an oil pump 12 is connected to the lubrication oil passage 19 provided in the cylinder block 1.
The lubricating oil supplied from the oil filter 80 is guided to an oil filter 80 attached to the side surface of the cylinder block 1 at a portion corresponding to the journal bearing 7 located between the two inner cylinder bores 5, 5 along the arrangement direction. Furthermore, the cylinder block 1 includes an oil passage 81 that guides the lubricating oil from the oil filter 80 upward toward the valve mechanism side, and an oil passage 82 that guides the lubricating oil downward.
and are drilled.

On the other hand, the bridge member 11 that interconnects the bearing caps 8... has a central oil passage 83 corresponding to the crankshaft 9.
and each balancer shaft 21, 22 on both sides of the central oil passage 83.
Side oil passages 84 and 85 respectively corresponding to the lateral oil passages 84 and 85 are bored parallel to the crankshaft 9.

The bridge member 11 also includes the oil passages 83, 84, 8.
A communication oil passage 86 that connects the oil passages 83 to 5 communicates with each other.
The oil passages 83 to 85 are perforated at a longitudinally intermediate portion thereof to be orthogonal to each of the oil passages 83 to 85.

The bridge member 11 and each bearing cap 8...
In order to supply lubricating oil to the supporting portion of the crankshaft 9, oil supply passages 87 are formed, each extending upward and communicating with the central oil passage 83 at its lower end. Also, the bearing hole 23.2 of the balancer shaft 21
4, the bridge member 11, the bearing cap 8, and the cylinder block 1 have a lower end connected to a side oil passage 84.
Oil supply passages 88 and 88 are drilled to communicate with the bearing holes 23 and 24, respectively, and the lower ends of the bridge member 11, the bearing cap 8, and the cylinder block 1 are provided at one end of the crankshaft 9 in the axial direction. An oil supply passage 89 that communicates with the side oil passage 84 extends vertically and is bored;
The oil supply passage 89 communicates with an oil supply passage 90 bored in the pump case 13 .

This oil supply path 90 is connected to the balancer shaft 2 in the pump case 13.
It communicates with the first bearing hole 13a, that is, the first bearing hole 13a, and also communicates with the rotary shaft 44 bearing portion, that is, the second bearing hole 42a in the gear case 42. The bridge member 11 is located at a portion corresponding to the bearing holes 25, 26, 27 of the first balancer shaft 22.
, the bearing cap 8 and the cylinder block 1 have lower ends communicating with the side oil passage 85 and upper ends communicating with the bearing hole 25.
Oil supply passages 91 communicating with the 26 and 27 ports are respectively drilled.

Oil passage 82 that guides lubricating oil from oil filter 80 downward
is communicated with the intermediate portion of the oil supply passage 88 at a portion corresponding to the bearing hole 24, and therefore the lubricating oil from the oil filter 80 passes through the oil supply passage 88 to each oil passage 83, 84, 85 of the bridge member ll. will be supplied to

Next, the operation of this embodiment will be described. The rotation of the crankshaft 9 drives both the first to fourth winding transmission systems T1 to T4. As a result, in the first winding transmission system Tl, the valve drive camshafts 30 and 31 are driven with a reduction ratio of 1/2 with respect to the crankshaft 9, and the water pump 32 is also driven. In addition, in the second winding transmission system T2, both balancer shafts 2
1 and 22 are driven in mutually opposite directions at a speed increasing ratio of 2/1 with respect to the crankshaft 9.

A first tensioner 46 for adjusting the tension of the first timing belt 36 in the first winding transmission system T1;
Second? ! Second timing belt 3 in hanging transmission system T2
Since the second tensioner 47 for adjusting the tension of the tensioner 9 is supported by the common support shaft 45, the tensioner arrangement can be made compact. Moreover, the first winding transmission system T
In l, valve train camshaft 30.31 requires large driving torque.
and to drive the water pump 32, the second:? !
: A larger driving load acts on the hanging transmission system T2, but since the first tensioner 46 is supported by the support shaft 45 with the first tensioner 46 axially inward than the second tensioner 47, the support shaft 4
The load applied to the tip side of 5 can be minimized.

Furthermore, by setting the angle α between the pressing directions of the first and second tensioners 46 and 47 to 90 degrees or more, preferably 120 degrees or more, the direction of the load applied to the support shaft 45 can be shifted to keep the overall load small. In combination with the arrangement of the first and second tensioners 46 and 47 described above, the support shaft 4
5 can be further suppressed.

Furthermore, the load on the second winding transmission system T2 is increased by the first winding transmission system T1.
Since the load is smaller than the load of It is possible to reduce the amount of protrusion and contribute to making the entire engine more compact.

Moreover, since the drive gear 40 and the driven gear 41 that are in mesh with each other to drive the first balancer shaft 21 in the reverse direction are helical gears, the meshing ratio can be improved compared to spur gears. It is possible to reduce the axial thickness of the gear case 42, and the gear case 42 can be made smaller. Further, due to the excellent engagement ratio, vibration and noise can be reduced, smooth rotation can be realized, and the durability of the second timing belt 39 can be improved.

Further, the tooth width D2 of the driven gear 41 is given margin widths D2a and D2b that accommodate the tooth width D1 of the driving gear 40 within the tooth width D2, so that the driving gear 40 and the driven gear 41 can move relative to each other in the axial direction. However, the effective contact width of both gears 40 and 41 can be ensured. Furthermore, since the tooth width D1 of the driving gear 40 is set smaller than the tooth width D2 of the driven gear 41 in order to ensure the above-mentioned effective contact width, the supporting portion of the rotating shaft 44 by the gear case 42 is made relatively long to ensure stable support. can be obtained.

Furthermore, when attaching the gear case 42 to the cylinder block 1, the rod-like member 94 is inserted into the through hole 92 and the first balancer shaft 21 is fixed, and the positioning index Ml and the cell i/pre-confirmation index M3 are aligned. , bolt 43
Attach the gear case 42 to the cylinder cylinder l along with the pump case 13. At this time, the driving gear 4o and the driven gear 41 start meshing with the above-mentioned indices Ml and M3 matching, and the driving gear 4o does not rotate in response to the movement of the gear case 42 toward the cylinder block l. It meshes with the driven gear 41. Therefore, when the installation is completed, the positioning index M1 is set to 6ffl L'? 21m mark M
2, the relative phase between the reverse drive driven pulley 37 and the first balancer shaft 21 is set in advance.

Therefore, when installing the gear case 42, align the positioning index M1 and the pre-setting confirmation index M3 at the beginning, and after completing the installation, align the positioning index M1 and the post-confirmation index M.
2 and 2 coincide with each other, the phases of the first balancer shaft 21 and the driven pulley 37 for reverse rotation driving can be adjusted to the preset phase. Moreover, both confirmation indicators M
2. Since M3 is provided at the tip of the protrusion 42a provided on the gear case 42, it is placed close to the positioning index M1, making positioning easy.

In the above embodiment, the post-setting confirmation indicator M2 and the pre-setting confirmation indicator M3 are arranged with an interval from each other, but a long arc-shaped indicator is provided on the gear case 42, and the arc-shaped indicator After setting both ends of , check indicator M2
It is also possible to use it as a pre-setting confirmation index M3.

Further, in the above embodiment, the case where the gear case 42 as a case member is attached to the pump case 13 attached to the cylinder block 1 has been described, but the present invention can also be applied to an arrangement in which the case member is attached directly to the engine body. Can be applied.

C6 Effects of the Invention As described above, according to the present invention, the driving gear and the driven gear are helical gears, the outer surface of the driven wheel for reverse drive is provided with a positioning index, and the outer surface of the case member is provided with a positioning index.
When the balancer shaft and the driven wheel for reverse drive reach the set phase with the driving gear completely meshed with the driven gear, the post-setting confirmation index corresponding to the positioning index No. 111 and the driving gear center at a position offset in the circumferential direction from the post-setting confirmation index by an amount corresponding to the angular displacement of the driven wheel for reverse drive according to the movement of the driven gear in the axial direction from the engagement completion position with the driven gear to the engagement start position. Since the pre-confirmation index is provided in a part separate from the driven wheel for reverse drive, it is possible to downsize and reduce vibration and noise, while making it extremely easy to align the phase between the balancer shaft and the driven wheel for reverse drive. be able to.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a longitudinal sectional side view, FIG. 2 is a view taken along the line ■-■ in FIG. 1, and FIG.
Figure 4 is a sectional view taken along the line ■-■ in the figure.
V-TV line sectional view, Figure 5 is the ■-V line sectional view of Figure 3,
Figure 6 is a cross-sectional view taken along the line Vl--Vl in Figure 3, Figure 7 is an enlarged cross-sectional view taken along line Figure 9 is a view from the ■ arrow in Figure 7, and Figure 10 is a view of Figure 7.
11 is a sectional view taken along the line XI-XI in FIG. 2, FIG. 12 is a plan view of the first tensioner, and FIG. 13 is a sectional view taken along the xm-xtu line in FIG. be. 9... Crankshaft, 21... Balancer shaft, 21a. 21, b... Eccentric weight portion, 37... Driven pulley for reverse drive as a driven wheel for reverse drive, 40... Drive gear, 41... Driven gear, 42... Case member Gear case, 44...rotating shaft, 94...gear chamber,
Snake... Engine body, Ml... Positioning index, M2.
・・Confirmation indicator after 7th turn, M3 ・・Pre-set confirmation indicator, T2 ・・Wrap transmission system Fig. 9

Claims (1)

[Claims] A balancer shaft having an eccentric weight portion is rotatably supported by the engine body, a rotary shaft is rotatably supported in parallel to the balancer shaft by a case member attached to the engine body, and a rotating shaft is provided at the inner end of the rotary shaft. A driving gear fixed to one end of the balancer shaft is meshed with a driven gear fixed to one end of the balancer shaft, and the rotating shaft is connected to the rotating shaft through a wrapped transmission system including a reverse drive driven wheel fixed to the outer end of the rotating shaft protruding from the case member. In a balancer shaft drive system for an internal combustion engine in which the drive wheel is interlocked and connected to the crankshaft, the drive gear and driven gear are helical gears, and a positioning index is provided on the outer surface of the driven wheel for reverse drive, and a positioning index is provided on the outer surface of the case member. , a post-setting confirmation index corresponding to the positioning index when the balancer shaft and reverse drive driven wheel reach the set phase with the driving gear fully engaged with the driven gear, and a post-set confirmation index corresponding to the positioning index when the driven gear is fixed. A position shifted in the circumferential direction from the post-setting confirmation index by an amount corresponding to the angular displacement of the driven wheel for reverse drive in response to moving the driving gear in the axial direction from the meshing completion position to the meshing start position with the driven gear. A balancer shaft drive device for an internal combustion engine, characterized in that a pre-set confirmation indicator is provided at a portion removed from a driven wheel for reverse drive.