JP2004245139A - Engine starter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To compact an engine by minimizing required space even when a balancer unit 21 actuated by a crank gear 20 is arranged in a starter A having the crank gear 20 for starting in the midway of a crankshaft 7 of the engine 1. <P>SOLUTION: The balancer unit 21 is formed of two shafts, the starter has a hollow unbalanced member 24 loosely engaging with the outer periphery of a shaft 23 as one balancer member, and a first intermediate gear 25 disposed rotation-integrally with this is arranged rotatably on one end side of the shaft 23 and meshes with the crank gear 20. A one-way clutch 30 is disposed between the shaft 23 and the first intermediate gear 25. The other end of the shaft 23 is projected outwardly from a housing 22 of the balancer unit 21, and is provided with a second intermediate gear 28 for receiving a driving force from the starter motor 35. Thanks to this constitution, using the balancer unit 21, the driving force from the starter motor 35 can be transmitted to the crankshaft 7. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a starting device in which a driving force from a starter motor is input to a gear provided on a crankshaft of an engine via an intermediate gear, and particularly to a starting device in which a balancer for reducing engine vibration is provided. It belongs to the technical field of arrangement structure of balancer and intermediate gear.
[0002]
[Prior art]
BACKGROUND ART Conventionally, as a starting device of this type of engine, as disclosed in Patent Document 1, for example, in order to shorten the overall length of an engine in which a plurality of cylinders are arranged in series, a crank outer peripheral surface of a web is provided. In some gears, a starting gear is formed directly by gear cutting, and a driving force from a starter motor is input to this gear via an intermediate gear unit including a plurality of gear elements. In this case, a balancer for reducing engine vibration is provided inside the oil pan, and a driven gear of the balancer also meshes with a starting gear of the crankshaft. That is, the gear of the crankshaft is provided as a gear for driving and starting the balancer.
[0003]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 2000-120514
[Problems to be solved by the invention]
However, in the conventional example (Patent Document 1), the starting gear of the crankshaft is also used for driving the balancer, but an intermediate gear for transmitting the driving force from the starter motor to the starting gear. The gear unit includes a starting gear, a freewheel gear, a small idle gear, a large idle gear, etc., in addition to a plurality of support shafts. However, there is a problem that a considerably large installation space is required in order to provide the engine and the demand for downsizing the engine.
[0005]
The present invention has been made in view of such a point, and an object of the present invention is to provide a starting device in which a starting crank gear is provided in the middle of a crankshaft of an engine. By devising the configuration of the power transmission system between the two, the space required when a balancer is installed is minimized, and the engine can be made more compact.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, in the solution of the present invention, a rotating element of a balancer is positively used as a path for inputting a driving force from a starter motor to a crank gear.
[0007]
Specifically, in the invention of claim 1, a crank gear is provided in the middle of the crankshaft of the engine, and a balancer disposed in an oil pan is driven by the crank gear. Is input to the crank gear. A shaft that is supported so as to extend in the longitudinal direction of the crankshaft as the balancer; a hollow unbalance member rotatably loosely fitted around the outer periphery of the shaft; A first intermediate gear that is rotatably integrated with the hollow unbalanced member on the side and meshes with the crank gear; and the balance weight is interposed between the first intermediate gear and the other end in the longitudinal direction of the shaft. And a second intermediate gear for receiving a driving force from the starter motor, and a transmission member capable of transmitting power from at least the second intermediate gear to the first intermediate gear.
[0008]
With the above configuration, at the time of starting the engine, the driving force is transmitted from the second intermediate gear that has received the driving force of the starter motor to the first intermediate gear via the transmission member, whereby the crankshaft is rotated. On the other hand, during operation of the engine, the first intermediate gear is rotationally driven by the crankshaft, and the hollow unbalance member rotates integrally therewith, thereby reducing engine vibration. In other words, a balancer for reducing engine vibration can be used as a transmission path for the driving force from the starter motor, and even if a balancer is installed, the required space is minimized, making the engine more compact. It is planned.
[0009]
Preferably, the transmission member in the balancer is a one-way clutch provided to transmit power from the shaft to the first intermediate gear (the invention of claim 2). With this configuration, only the first intermediate gear meshing with the crank gear and the hollow unbalance member rotate with the crankshaft during operation of the engine among the constituent members of the balancer, thereby reducing the operating loss of the engine. It can be extremely small.
[0010]
Specifically, first, by making the unbalanced member having a balance weight hollow, while obtaining the necessary necessary to cancel the exciting force generated by the operation of the engine, the mass of the balance weight itself is relatively small. Therefore, the force for driving the unbalance member can be reduced. Also, only the hollow unbalanced member is driven by the first intermediate gear, and the shaft as well as the output shaft of the second intermediate gear and the starter motor does not rotate. Therefore, the operating loss of the engine for driving the balancer is extremely small.
[0011]
In particular, in the case of an in-line four-cylinder engine, the balancer is a biaxial type having a pair of left and right balancers rotating in parallel and in opposite directions to each other, and one of the pair of balancers is hollow. It is preferable that a transfer drive gear for driving the other balancer member is provided integrally with the hollow unbalance member so as to rotate integrally with the hollow balance member (the invention of claim 3). With this configuration, the secondary rotational vibration of the in-line four-cylinder engine can be canceled by the two-axis balancer, and the engine vibration can be effectively reduced.
[0012]
The first intermediate gear includes a gear main body rotatably supported on an outer periphery of a shaft, and a hollow extending portion provided to extend along an axis of the shaft from an inner peripheral side of the gear main body. Preferably, the distal end of the hollow extension is connected to a hollow unbalance member, and a transfer drive gear is provided on the outer periphery of the hollow extension (claim 4). In this case, the hollow extension for connecting the main body of the first intermediate gear to the hollow unbalanced member can be effectively used as a member for providing the transfer drive gear.
[0013]
Alternatively, the first intermediate gear extends from an inner peripheral side of the gear main body rotatably supported on an outer periphery of a shaft toward both ends in a longitudinal direction of the shaft along an axis of the shaft. The first and second hollow extension portions are provided as described above, and the distal end portion of the first hollow extension portion is connected to the hollow unbalance member, while the outer periphery of the second hollow extension portion is provided. A transfer drive gear may be provided (the invention of claim 5). In this case, the transfer drive gear can also be used as a component of the oil pump of the engine (the invention of claim 6).
[0014]
Furthermore, it is preferable that the main body of the first intermediate gear is supported by a ball bearing on the outer periphery of the shaft (the invention of claim 7). In this case, since the positioning accuracy between the first intermediate gear and the shaft is increased, the backlash between the first intermediate gear and the crank gear can be easily managed.
[0015]
In addition, the starter motor is preferably disposed outside the oil pan in consideration of reliability and maintainability. In this case, the starter motor is inserted through a through hole formed in the oil pan. The pinion provided at the tip of the starter motor may be engaged with the second intermediate gear of the balancer (the invention of claim 8).
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0017]
FIG. 2 shows a configuration of a main body of an engine 1 according to an embodiment of the present invention. The engine 1 is configured by assembling a cylinder head 4 made of an aluminum alloy with a cylinder head 3 made of an aluminum alloy. A cylinder head cover 5 is attached to an upper portion of the cylinder head 4, and an oil pan 6 is attached to a lower portion of the cylinder block 3 via a gasket. The oil pan 6 is made of cast material having relatively high rigidity and excellent sound insulation. In this embodiment, the oil pan 6 is made of an aluminum alloy like the cylinder block and the like, but may be made of cast iron, for example.
[0018]
The cylinder block 3 is of a deep skirt type in which the left and right side walls of the crankcase extend below the axis x1 of the crankshaft 7 respectively. As shown in FIG. 3, banks 3a and 3b project outward from the upper end to the lower end, respectively. A timing chain or the like for driving a valve train is accommodated between a front cover 8 (indicated by phantom lines in FIG. 3) attached to the bank portions 3a and 3b and a front wall portion of the cylinder block 3. It has become so.
[0019]
The front cover 8 is attached so as to extend from the front surface of the cylinder block 3 to the front surface of the oil pan 6 as shown by the phantom line in FIG. However, it becomes very good in the front-rear direction of the engine. This, coupled with the fact that the rigidity of the oil pan 6 itself is high, the positioning accuracy of the starter motor 35 attached to the oil pan with respect to the cylinder block 3 is extremely high as described later.
[0020]
The engine 1 of this embodiment is an in-line four-cylinder gasoline engine in which four cylinders 2, 2,... (See FIG. 1) are linearly arranged in a cylinder block 3. In the multi-cylinder engine described above, the longitudinal direction is generally referred to as an engine front-rear direction, and the side on which the timing chain and the like are disposed is referred to as an engine front side. Hereinafter, similar names are used in this specification, and the engine front side is simply abbreviated to the front side unless otherwise specified.
[0021]
As shown in FIG. 2, each cylinder 2 has a piston 9 fitted therein so as to reciprocate along its axis, and a cylinder sandwiched between the upper surface of each piston 9 and the lower surface of the cylinder head 4. The space in 2 constitutes the combustion chamber 10. Two inclined surfaces are formed on the ceiling of the combustion chamber 10, that is, on the lower surface of the cylinder head 3, and two intake ports 11 and two exhaust ports 12 are respectively opened. Further, intake and exhaust valves 15 and 16 that are opened and closed by cam shafts 13 and 14 that are supported by the cylinder head 5 are provided. Although not shown, a spark plug is provided on the ceiling of each cylinder 2 facing the combustion chamber 10 so as to be surrounded by intake and exhaust valves 15 and 16.
[0022]
Each piston 9 is connected to the crankshaft 7 by a connecting rod 17. The crankshaft 7 is made of ductile cast iron, for example, and is rotatably supported on the cylinder block 3 by five journal bearings 18, 18,... (Only one is shown in FIG. 2) in this embodiment. That is, although shown in phantom lines only in FIG. 1, the cylinder block 3 has a total of five main bearings 18a, 18a, 18a, 18a, with the lower ends of four cylinders 2, 2,. Are provided, and a bearing cap 18b is attached to each of the main bearing portions 18a to form a journal bearing 18. Further, the five journal bearings 18, 18,. (See FIG. 4).
[0023]
As shown in FIG. 1, the crankshaft 7 is of a full counterweight type having eight counterweights 7a, 7a,..., And the sixth one from the front of the engine is formed in a disk shape. A ring-shaped helical gear 20 is fixed to the outer periphery by press-fitting. The helical gear 20 drives the balancer unit 21 disposed in the oil pan 6 during operation of the engine 1, and receives driving force from a starter motor 35 described later via the balancer unit 21 at the time of starting the engine. It has become. Hereinafter, the gear 20 for driving and starting the balancer is referred to as a crank gear 20, but this gear 20 is not necessarily provided on the sixth counterweight 7a from the front, and may be provided on another counterweight 7a. In the case of a crankshaft that is not a full counterweight type, it can be provided on the crank web.
[0024]
Next, the configuration of the balancer unit 21 will be described in detail. The balancer unit 21 basically rotates two balancer members juxtaposed in the oil pan 6 below the crankshaft 7 in directions opposite to each other at twice the speed of the crankshaft 7 to thereby provide an in-line four-cylinder engine. This is a two-shaft type that cancels the secondary vibration of the first rotation, but as a characteristic part of the present invention, when the engine 1 is started, a driving force from a starter motor 35 described later is input to the gear 20 of the crankshaft. It is configured to be a path for
[0025]
As shown in FIG. 4 in addition to FIG. 1, the balancer unit 21 is disposed such that the upper surface of the housing 22 is in contact with the lower surface of the bearing beam 19. It is directly fixed to the lower part of the cylinder block 3 via the bracket part which extends upward by two each. As shown in detail in FIG. 5, one of the two balancer members housed in the housing 22 is a shaft 23 supported by the housing 22 so as to extend in the engine front-rear direction (the longitudinal direction of the crankshaft 7). A hollow unbalance member 24 rotatably and loosely fitted on the outer periphery of the shaft 23, and a coaxially and rotatably disposed at one longitudinal end of the shaft 23 (the rear side of the engine on the right side in the figure). A first intermediate gear 25 meshes with the crank gear 20.
[0026]
The shaft 23 has a front end and a rear end rotatably supported by bearing holes 26 and 27 provided in the front and rear side walls 22a and 22b of the housing 22, respectively. Among them, the front bearing hole 26 penetrates through the front side wall portion 22a of the housing 22, and the front end of the shaft 23 inserted therethrough projects outside the housing 22. The second intermediate gear 28 that receives the driving force is fixed so as to rotate integrally with a spline or the like. In other words, the second intermediate gear 28 is disposed at the other longitudinal end of the shaft 23 with the hollow unbalance member 24 interposed between the second intermediate gear 28 and the first intermediate gear 25.
[0027]
An oil passage 23a is formed inside the shaft 23 so as to extend along the axis x2 over substantially the entire length thereof. The rear end side of the oil passage 23a communicates with a lubricating oil passage 29 formed in a rear side wall portion 22b of the housing 22, and lubricating oil (engine oil) introduced from the oil gallery of the engine 1 through the lubricating oil passage 29. ) Is distributed to and supplied to a one-way clutch 30 and bearing portions 31 and 32 described later.
[0028]
The hollow unbalance member 24 is formed by integrally forming a cylindrical portion 24a coaxially arranged on the outer periphery of the shaft 23 and a balance weight portion 24b having a substantially semicircular cross section. The rear end is connected to the front end of the first intermediate gear 25 by a spline or the like so as to rotate integrally with the front end of the first intermediate gear 25 while being supported by a slide bearing or the like on the rear surface of the front side wall 22a of the housing 22. During the operation of the engine 1, the hollow unbalance member 24 rotates in synchronization with the crankshaft 7, so that the exciting force of the engine 1 can be reduced. In addition, by using the hollow unbalanced member 24, the mass itself of the member 24 can be made relatively small while obtaining the required measurement necessary to cancel the exciting force generated by the operation of the engine 1. As a result, loss for driving the balancer can be reduced.
[0029]
The first intermediate gear 25 has a truncated conical shape that gradually increases in diameter from the front side to the rear side of the engine as a whole, and the front end of the small diameter portion 25a located on the front side is formed with the hollow unbalance member 24. On the rear end of the large-diameter portion 25b located on the rear side while being joined by a spline or the like, a circular flange 25c protruding radially outward so as to be substantially perpendicular to the axis x2 of the shaft 23. The helical gear is formed directly on the outer periphery of the flange 25 by gear cutting.
[0030]
In other words, the large-diameter portion of the first intermediate gear 25 is a gear body in which a helical gear that meshes with the crank gear 20 is formed (hereinafter also referred to as a gear body 25b). An annular space is formed between the inner periphery of the gear main body 25b and the outer periphery of the shaft 23, in which a driving force is transmitted from the shaft 23 to the first intermediate gear 25. On the other hand, a one-way clutch 30 that interrupts the transmission of power in the opposite direction and a ball bearing 31 that rotatably supports the main body 25b of the first intermediate gear 25 with respect to the outer periphery of the shaft 23 are provided. I have. That is, the ball bearing 31 is arranged on the inner periphery of the first intermediate gear 25 that directly meshes with the crank gear 20, and the positioning accuracy between the first intermediate gear 25 and the shaft 23 is increased, so that the second The backlash between the first intermediate gear 25 and the crank gear 20 can be easily managed.
[0031]
On the other hand, when viewed from the gear body 25b, the small-diameter portion 25a of the first intermediate gear 25 is a hollow provided so as to extend from the inner peripheral side of the gear body 25b to the front of the engine along the axis x2 of the shaft 23. A needle bearing 32 is disposed between the inner periphery of the hollow extension 25a and the outer periphery of the shaft 23, and the hollow extension 25a is a hollow extension. A transfer drive gear 33 for transmitting rotational drive force to the other balancer member (not shown) is provided on the outer periphery of the extension portion 25a by a spline or the like. That is, although not shown, the other balancer member includes a shaft supported by the housing 22 similarly to the one balancer member, a hollow unbalance member rotating around the shaft, and an integral member with the hollow unbalance member. And a transfer driven gear that is rotatably connected to the transfer drive gear 33. The transfer driven gear meshes with the transfer drive gear 33.
[0032]
Therefore, the rotation of the crankshaft 7 during the operation of the engine is transmitted from the first intermediate gear 25 to the one hollow unbalance member 24, and is transferred by the transfer drive gear 33 and the driven gear to the other hollow unbalance member. Is also transmitted to As a result, the two hollow unbalance members rotate in mutually opposite directions in synchronization with the crankshaft 7 of the engine 1, and cancel vibration mainly caused by the secondary inertial force of the piston.
[0033]
Here, since the one-way clutch 30 is provided between the first intermediate gear 25 and the shaft 23, even when the two hollow unbalance members 24 are rotated as described above, the shaft 23 and the In this manner, the starter motor 35 and the like that are drivingly connected thereto are not rotated. That is, in the balancer unit 21, only the first intermediate gear 25 and the two hollow unbalance members 24 that mesh with the crank gear 20 rotate together with the crankshaft 7 during the operation of the engine. By rotating only the members, the operating loss of the engine 1 for driving the balancer can be reduced.
[0034]
Next, the connection between the balancer unit 21 and the starter motor 35 will be described. The main body 36 of the starter motor 35 is disposed outside the oil pan 6, and the tip end of the main body 36 is inserted into the through hole 37 of the oil pan 6. It has been inserted. That is, as shown in FIGS. 2 and 3, a starter motor housing 6a is formed in the front right side of the oil pan 6 so as to be recessed inward so that the main body 36 of the starter motor 35 can be generally housed. Have been. The wall surface of the oil pan 6 corresponding to the inner surface of the starter motor housing portion 6a (the end surface on the rear side of the engine) is formed substantially flat, and a through hole for inserting the distal end of the starter motor 35 therethrough. 37 are formed. The outer wall surface of the oil pan surrounding the through hole 37 is a substantially flat flange surface.
[0035]
On the other hand, on the distal end side of the cylindrical main body portion 36 of the starter motor 35, a substantially rectangular flange portion 38 that extends outward so as to be substantially perpendicular to the axis x3 is provided. On the side, an inserted portion 39 to be inserted into the through hole 37 of the oil pan 6 is provided. The inserted portion 39 is a cover portion that accommodates the motor shaft of the starter motor 35 and the pinion 40, is formed in a hemispherical shape as a whole, and is cut so that a part of the pinion 40 inside is exposed. It is a missing half-split shape. Then, the inserted portion 39 is inserted into the through hole 37 of the oil pan 6 in the front-rear direction of the engine, and the pinion 40 is connected to the balancer unit 21 in a state where the flange portion 38 is in contact with the flange surface of the oil pan 6. The flange 38 is fastened and fixed to the flange surface of the oil pan 6 by bolts in this state.
[0036]
With such a configuration, when the starter motor 35 operates at the time of starting the engine 1 and its motor shaft rotates, the rotational driving force input from the pinion 40 on this motor shaft to the second intermediate gear 28 of the balancer unit 21 is reduced. The power is transmitted to the first intermediate gear 25 via the shaft 23 and the one-way clutch 30, whereby the crankshaft 7 of the engine 1 is driven.
[0037]
FIG. 3 shows a state in which the intake / exhaust system, accessories and the like of the engine 1 are all removed, and the cylinder block 3 and the oil pan 6 are viewed obliquely from the right front thereof. 35 are stored, and reference numerals 42, 42,... Shown in the figure are ribs for reinforcing the side wall of the cylinder block 3, and reference numerals 43, 43,. It is a boss formed on the side wall of the cylinder block 3 for attaching accessories and the like.
[0038]
FIG. 4 shows the state of connection between the balancer unit 21 and the starter motor 35 when the oil pan 6 is virtually removed and the engine 1 is viewed from below. Reference numeral 44 denotes a relay of the starter motor 35, and reference numerals 45... Denote a resin oil strainer pipe for sucking up engine oil stored in the oil pan 6, although not shown.
[0039]
Therefore, according to the engine starter A according to this embodiment, the secondary rotation of the rotation is driven by driving the two-axis secondary balancer 21 by the gear 20 provided on the crankshaft 7 of the in-line four-cylinder engine 1. The vibration of the engine 1 can be effectively reduced by canceling, and the balancer unit 21 is used as a path for transmitting the driving force from the starter motor 35 at the time of starting the engine. Space can be minimized, whereby the engine 1 can be made more compact.
[0040]
Moreover, in the balancer unit 21, a hollow unbalance member 24 is used as the balancer member, and the shaft 23 supporting the member 24 is configured not to receive the driving force from the crankshaft 7. The operating loss of the engine 1 for driving is extremely small. That is, an increase in operating loss caused by using the balancer unit 21 as a path for starting the engine can be minimized.
[0041]
Further, in this embodiment, the oil pan 6 is made of a casting having relatively high rigidity, and the inserted portion 39 at the tip of the starter motor 35 fixed thereto is connected to the second intermediate gear on the balancer unit 21 side in the oil pan 6. Since the main body 36 of the starter motor 35 is disposed outside the oil pan 6, the reliability is high and the maintenance can be easily performed.
[0042]
It should be noted that the configuration of the present invention is not limited to the above-described embodiment, but includes other various configurations. That is, in the balancer unit 21 of the embodiment, the transfer driven gear 33 is disposed here by effectively utilizing the hollow extension 25a of the first intermediate gear 25 that meshes with the gear 20 of the crankshaft 6. However, the position of the transfer drive gear 33 is not limited to the above position (see FIG. 5).
[0043]
That is, as shown in FIG. 6, for example, the first intermediate gear 50 is composed of a main body 50b, a hollow extension 50a (first hollow extension), and a flange 50c, similarly to the above-described embodiment. It is also possible to attach a hollow tubular member 51 so as to extend rearward from the engine along the axis of the shaft 23 from the inner peripheral side of the main body 50b, and to dispose the transfer drive gear 52 here. In the illustrated example, a flange 51a is provided at the front end of the tubular member 51, and the outer periphery thereof is attached to the gear main body 50a of the first intermediate gear 50 by a spline or the like so as to rotate integrally therewith. I have. In other words, the first intermediate gear 50 has first and second hollow extending portions provided so as to extend in the front-rear direction of the engine from the inner peripheral side of the gear body 50b (second). Is the tubular member 51).
[0044]
In the example shown in the figure, a gear pump 53 is integrally provided on the rear side wall portion 22 b of the housing 22 of the balancer unit 21, and the transfer drive gear 52 provided on the rear end side of the cylindrical member 51 is connected to the gear pump 53. Also serves as a rotor. With this configuration, the oil pump of the engine 1 can be configured by using the gears of the balancer unit 21 disposed in the oil pan 6, so that the size of the engine 1 can be further reduced. In the example shown in the figure, the ball bearing 31 is eliminated with the addition of the cylindrical member 51, and two needle bearings 32 are used instead.
[0045]
【The invention's effect】
As described above, according to the engine starter according to the first aspect of the present invention, the crank gear is provided in the middle of the crankshaft, thereby driving the balancer, and reducing the driving force from the starter motor when starting the engine. In the gear input to the crank gear, by using the rotating element of the balancer as a power transmission path for inputting the driving force from the starter motor to the crank gear, a starter and a balancer are installed. Space can be minimized and the engine can be made compact.
[0046]
According to the invention of claim 2, by providing the one-way clutch that allows transmission of power from the shaft of the balancer unit to the first intermediate gear, the number of members that rotate together with the crankshaft during operation of the engine is minimized. Operation loss can be extremely reduced.
[0047]
According to the third aspect of the invention, the vibration of the in-line four-cylinder engine can be effectively reduced by the two-shaft secondary balancer.
[0048]
According to the fourth aspect of the present invention, the hollow extending portion provided on the first intermediate gear of one balancer member can be effectively used as an installation member of a transfer drive gear for driving the other balancer member.
[0049]
According to the fifth and sixth aspects of the present invention, the transfer drive gear can also be used as a component of the oil pump of the engine.
[0050]
According to the seventh aspect of the present invention, by arranging the ball bearing on the inner periphery of the main body of the first intermediate gear, the positioning accuracy of the first intermediate gear is improved, and the backlash between the first intermediate gear and the crank gear can be easily managed. Can be
[0051]
According to the invention of claim 8, the reliability and the maintainability can be improved by disposing the main body of the starter motor outside the oil pan.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an engine starter A according to an embodiment of the present invention.
FIG. 2 is a partially cutaway view showing a configuration of an engine body.
FIG. 3 is a perspective view showing a starter motor mounted outside an oil pan.
FIG. 4 is a diagram showing a connection state between a starter motor and a balancer unit from below an engine, virtually removing an oil pan;
FIG. 5 is a partial cross-sectional view illustrating a configuration of a balancer unit.
FIG. 6 is a diagram corresponding to FIG. 5 according to another embodiment in which a transfer drive gear is used as a rotor of a gear pump.
[Explanation of symbols]
A engine starter 1 engine 2, 2, ... cylinder (cylinder)
3 Cylinder block 6 Oil pan 7 Crankshaft 20 Crank gear 21 Balancer unit 22 Housing 23 Shaft 24 Hollow unbalance member 25 First intermediate gear 25a Hollow extending portion 25b Gear body 28 Second intermediate gear 30 One-way clutch 31 Ball bearing 33 Transfer drive gear 35 Starter motor 39 Insertion part (tip side)
40 pinion

Claims (8)

A starter in which a crank gear is provided in the middle of a crankshaft of an engine, and a balancer disposed in an oil pan is driven by the crank gear, and a driving force from a starter motor is input to the crank gear when starting the engine. In the device,
The balancer is
A shaft supported to extend in a longitudinal direction of the crankshaft;
A hollow unbalance member having a balance weight and rotatably loosely fitted around the outer periphery of the shaft;
A first intermediate gear that is provided rotatably with the hollow unbalance member on one end side in the longitudinal direction of the shaft and meshes with the crank gear;
A second intermediate gear that is provided on the other end in the longitudinal direction of the shaft with the balance weight interposed between the first intermediate gear and receives driving force from the starter motor;
A transmission member capable of transmitting power from at least the second intermediate gear to the first intermediate gear. In claim 1,
The engine starting device according to claim 1, wherein the transmission member is a one-way clutch provided to transmit power from the shaft to the first intermediate gear. In any of claims 1 or 2,
The engine is an in-line four-cylinder engine,
The balancer is a two-axis type having a pair of left and right balancer members that rotate in parallel and in opposite directions to each other,
One of the pair of balancer members is a hollow unbalanced member, and a transfer drive gear for driving the other balancer member is provided integrally with the hollow unbalanced member for rotation. Starting device. In claim 3,
The first intermediate gear has a gear main body rotatably supported on the outer periphery of the shaft, and a hollow extension provided to extend from the inner peripheral side of the gear main body along the axis of the shaft. And
An engine starting device, wherein a distal end of the hollow extension is connected to a hollow unbalance member, and a transfer drive gear is provided on an outer periphery of the hollow extension. In claim 3,
The first intermediate gear is provided so as to extend from the inner peripheral side of the gear main body to the both ends in the longitudinal direction along the axis of the shaft from the inner peripheral side of the gear main body. First and second hollow extending portions provided,
The tip of the first hollow extension is connected to a hollow unbalance member,
An engine starter, wherein a transfer drive gear is provided on an outer periphery of the second hollow extension. In claim 5,
An engine starting device wherein the transfer drive gear is a component of an engine oil pump. In any one of claims 4 to 6,
The starting device for an engine, wherein a main body of the first intermediate gear is supported by a ball bearing on an outer periphery of the shaft. In any one of claims 1 to 7,
A starter motor is provided outside the oil pan, and a front end side of the starter motor is inserted into a through hole formed in the oil pan, and a pinion provided at the front end engages with a second intermediate gear of the balancer. A starting device for an engine, comprising:

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