JPH08261006A - Crankshaft dynamic damper for engine - Google Patents

Abstract

PURPOSE: To provide a crankshaft dynamic damper of an engine capable of preventing the durability of an elastic member from being reduced by the rotating force of a starter motor. CONSTITUTION: In a crankshaft dynamic damper 50 of an engine in which a rotating force of a starter motor 33 is transmitted to a crankshaft 11 through a one-way clutch 42 mounted at the end part of the crankshaft 11, the dynamic damper 50 is arranged at the right end part 11c on the outside of the one-way clutch 42 of the crankshaft 11 separately and independently from the one-way clutch 42.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dynamic damper for preventing torsional resonance of a crankshaft.

[0002]

2. Description of the Related Art Heretofore, there has been proposed one in which a dynamic damper is provided to prevent torsional resonance of a crankshaft during engine operation (for example, actual open flat plate 3-8).
(See Japanese Patent No. 4457). As shown in FIG. 8, an outer wheel 104 (weight) of a one-way clutch 103 is connected to a cylindrical boss portion 101 fixed to a crankshaft 100 via a rubber elastic body 102, and an inner wheel 105 of the inner wheel 105 is connected. It has a structure in which the ring gear 106 is engaged with a drive gear of a starter motor (not shown) via an idle gear. In this structure, when the engine is started, the rotation of the starter motor is changed as indicated by the arrow.
06 to the outer wheel 104 via the inner wheel 105 and the roller 107, and the crankshaft 1 from the outer wheel 104 via the elastic member 102.
It is designed to be transmitted to 00.

[0003]

However, in the above-mentioned conventional dynamic damper, since the rotational force from the starter motor is transmitted to the crankshaft via the elastic body, the durability of the elastic body may be deteriorated. There is a concern that the damper function will be impaired.

The present invention has been made to solve the above-mentioned conventional problems, and provides a crankshaft dynamic damper for an engine capable of preventing the durability of an elastic body from being deteriorated and the damper function from being impaired. The purpose is to do.

[0005]

According to a first aspect of the present invention, there is provided an engine having a structure in which a rotational force of a starter motor is transmitted to a crankshaft via a one-way clutch attached to an end of the crankshaft. The crankshaft dynamic damper is characterized in that the dynamic damper is disposed and fixed to an outer portion of the crankshaft from the one-way clutch.

According to a second aspect of the present invention, the dynamic damper has a cylindrical weight formed through an elastic member on the outer peripheral surface of the hub, which is formed by integrally forming a radially extending flange portion on the inner peripheral surface of the cylindrical hub body. Is fitted and connected, and the flange portion of the hub is fixed to the end surface of the crankshaft by bolting.

According to a third aspect of the invention, in the dynamic damper, the hub portion is integrally formed with the boss portion of the output side outer wheel of the one-way clutch, and the cylindrical weight is fitted to the outer peripheral surface of the hub portion via the elastic member. It is characterized in that the hub portion is fixed to the outer end portion of the crankshaft.

According to a fourth aspect of the present invention, the dynamic damper is constructed by fitting and connecting a weight to the outer peripheral surface of a cylindrical hub with a bottom through an elastic member, and the cylindrical shape of the hub is a one-way clutch. It is characterized in that it is press-fitted into the boss portion of the output side outer wheel and the bottom portion is bolted and fixed to the end surface of the crankshaft.

The invention of claim 5 is characterized in that the weight is formed with an extension portion surrounding the outer peripheral portion of the one-way clutch, and the invention of claim 6 is such that at least a part of the weight is more than the remaining part. It is characterized by being made of a material having a large specific gravity.

[0010]

According to the first aspect of the present invention, since the dynamic damper is independently arranged and fixed to the outer side of the one-way clutch of the crankshaft, the rotational force from the starter motor is not transmitted to the crankshaft through the elastic member. Therefore, the durability of the elastic member is not deteriorated by the rotational force, and the damper function is not hindered.

According to a second aspect of the present invention, the dynamic damper has a structure in which a weight is fitted and connected to the outer peripheral surface of the hub, which is formed by integrally forming a flange portion on the inner peripheral surface of the hub body, through an elastic member, and the flange is formed. Since the part is bolted and fixed to the end surface of the crankshaft, the DYNAC damper can be separated from the one-way clutch. Also, since the hub is arranged so that the hub body surrounds the boss portion of the outer wheel, it is possible to effectively utilize the empty space around the end of the crankshaft to arrange the dynamic damper and suppress the amount of protrusion to the outside in the crankshaft direction. Can secure a bank angle.

According to the invention of claim 3, in addition to the function of the invention of claim 2, since the hub portion of the dynamic damper is integrally formed with the boss portion of the outer wheel of the one-way clutch, the number of parts can be reduced and the dynamic portion can be reduced. The damper can be made compact.

According to the fourth aspect of the present invention, since the tubular portion of the hub is press-fitted into the boss portion of the outer wheel and the bottom portion is bolted and fixed to the end face of the crankshaft, the mounting force of the dynamic damper can be improved and When the slack is generated, the slack of the dynamic damper can be avoided and the influence on the damper function can be prevented.

In the invention of claim 5, since the weight is formed with the extension portion surrounding the outer peripheral surface of the one-way clutch,
By effectively utilizing the dead space around the end of the crankshaft, the inertial mass of the weight can be increased while ensuring the bank angle, and the damper function can be further improved.

According to the sixth aspect of the present invention, since at least a part of the weight is made of a material having a large specific gravity, the inertial mass can be increased without increasing the size, and the damper function can be improved. Further, when the inertial mass is the same, the size can be reduced.

[0016]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 to 3 are views for explaining a crankshaft dynamic damper according to an embodiment of the invention of claims 1 and 2, and FIG. 1 is a sectional view showing the crankshaft dynamic damper of the present embodiment, and FIG. FIG. 3 is a side view and a rear view of an engine equipped with the crankshaft dynamic damper of the present embodiment, respectively. Here, the left and right in this embodiment are the left and right when viewed from the rear of the engine.

In the figure, reference numeral 1 denotes a water-cooled 4-cycle parallel 4-cylinder engine mounted on a motorcycle, which is mounted on a vehicle with its cylinder axis inclined forward. In the engine 1, the cylinder head 3 is laminated on the upper mating surface of the cylinder block 2 and fastened with bolts, the head cover 4 is attached to the upper mating surface of the cylinder head 3, and the lower mating surface of the cylinder block 2 is mounted. The crankcase 5 is connected, and the oil pan 6 is connected to the lower surface of the crankcase 5. The crankcase 5 has a structure in which the transmission case is integrated and is divided into upper and lower parts.

A piston 9 is slidably inserted in each cylinder bore of the cylinder block 2, and the piston 9 is connected to a crank pin 11a of a crank shaft 11 by a connecting rod 10. The cylinder head 3
Combustion recess 3a is formed on the surface facing each piston 9, and intake valves 12 and exhaust valves 13 can be opened and closed in the two intake valve openings and the two exhaust valve openings that open in the recess 3a. It is arranged. The intake valve opening is an intake port 14 and the exhaust valve opening is an exhaust port 15 leading to the rear wall and the front wall of the cylinder head 3, respectively, and an automatic variable valve having a throttle valve 16 built in at the upper end of the intake port 14. Venturi type vaporizer 17 is connected,
Further, an air cleaner 18 is connected to the upstream end of the vaporizer 17.

Inside the head cover 4, a pair of cam shafts 1 for driving the intake valve 12 and the exhaust valve 13 to open and close.
9 and 19 are arranged in parallel with each other. Each cam shaft 1
Sprockets 20 and 21 are fixed to the central portion of the shaft 9 of the crankshaft 11 and the central portion of the crankshaft 11, respectively, and the camshaft 19 is fixed by a timing chain 22 wound around the sprockets 20 and 21. To rotate.

A main shaft 25 constituting a speed change mechanism is arranged in the crankcase 5 in parallel with the crankshaft 11, and a drive shaft 26 is arranged in parallel with the main shaft 25 behind the main shaft 25. ing. The left end portion of the drive shaft 26 projects outward from the crankcase 7, and a drive sprocket 27 that rotationally drives the rear wheels is coupled to the projection portion via a drive chain (not shown). A clutch mechanism 28 is connected to the right end of the main shaft 25, and an output gear 11b of the crankshaft 11 meshes with an input gear 28a of the clutch mechanism 28. Further, the clutch mechanism 28 is configured to connect and disconnect the engine power by advancing and retracting the push rod 28b inserted in the axis of the main shaft 25.

A generator 30 is connected to the left end of the crankshaft 11, and the rotor of the generator 30 functions as a flywheel. Further, an oil element 29 is connected to the lower portion of the front wall of the crankcase 5, which filters the lubricating oil from the oil pump and supplies it to each component of the engine 1.

A starter motor 33 is arranged on the upper surface of the crankcase 5, and the motor 33 is bolted and fixed to a boss portion (not shown) integrally formed with the crankcase 5. A starter case 3 for covering the starter gear train is provided on the right side wall mating surface 5a of the crankcase 5.
4 is detachably mounted with bolts.

A rotating shaft 33a of the starter motor 33 is located at the upper end of the starter case 34, and an idler gear 35 arranged coaxially with the rotating shaft 33a is connected by a connecting member 36. The idler gear 35 is rotatably supported by bearings 37 and 38. Two intermediate gears 39 and 40 are rotatably supported by shafts 41 and 41 in the center of the starter case 34, and the upper intermediate gear 39 meshes with the idler gear 35.

A right end portion 11c of the crankshaft 11 projects from a lower portion inside the starter case 34, and a one-way clutch 42 is attached to the right end portion 11c. This one-way clutch 42 has a schematic structure in which a large number of rollers 45 are provided between an inner wheel 43 on the input side and an outer wheel 44 on the output side. Rotational force is applied only from the inner wheel 43 to the outer wheel 44. It is transmitted and idles in the opposite direction.

The inner wheel 43 has a bearing 46.
It is rotatably attached to the right end portion 11c of the crankshaft via. A ring gear 47 is coupled to the inner side of the inner wheel 44 in the axial direction, and the ring gear 47 meshes with the lower intermediate gear 40. A flange 48 is provided on the outer side in the axial direction of the outer wheel 44 with a bolt 48a.
The boss portion 4 of the flange 48 is fastened and fixed by
8b is taper-fitted to the right end portion 11c of the crankshaft and is also connected via a key 49. As a result, the rotational force of the starter motor 33 is sequentially reduced by the idler gear 35, the intermediate gears 39 and 40, and the ring gear 47, and transmitted from the inner wheel 43 to the crankshaft 11 via the outer wheel 44. The flange 48 can be removed from the taper portion of the right end portion 11c by removing the bolt 48a and screwing the bolt into the screw hole 48c of the flange 48.

The right end portion 11c of the crankshaft 11
A dynamic damper 50, which characterizes the present embodiment, is arranged separately from the one-way clutch 42. The dynamic damper 50 includes a hub 51 formed by integrally forming a radially extending flange portion 51b in a cylindrical hub body 51a, a sleeve 52 press-fitted to the outer peripheral surface of the hub body 51a, and a sleeve 52 of the sleeve 52. It is composed of a rubber-made cylindrical elastic member 53 fixed to the outer peripheral surface and an iron ring weight 54 fixed to the outer peripheral surface of the elastic member 53.

The ring weight 54 has a body portion 54a having a shape along the inner surface of the starter case 34 and a bolt 4 attached thereto.
The ring-shaped member has a cutout portion 54b for avoiding interference with 8a. Further, the hub body 51a is coaxially arranged so as to surround the outer periphery of the boss portion 48b of the flange 48, the flange portion 51b is fixed to the end surface of the crankshaft right end portion 11c by a bolt 55, and the boss portion 48b. The end face of is being pressed.

Next, the function and effect of this embodiment will be described. In the present embodiment, the dynamic damper 50 is provided on the right end portion 11 outside the one-way clutch 42 of the crankshaft 11.
Since it is arranged separately from the one-way clutch 42 in c, the rotational force from the starter motor 33 is directly transmitted to the crankshaft 11 via the one-way clutch 42, and no rotational force is applied to the elastic member 53. .
As a result, the durability of the elastic member 53 can be prevented from lowering due to the motor driving force during cranking, and the function as a damper can be secured.

Further, in this embodiment, since the dynamic damper 50 is arranged so that the hub body 51a overlaps the boss portion 48b of the one-way clutch 42, the empty space around the right end portion 11c of the crankshaft 11 is effectively used. Can be placed. Further, since the amount of protrusion of the dynamic damper 50 to the outside in the axial direction can be suppressed, it is possible to secure the vehicle body inclination angle (bank angle) until it comes into contact with the road surface when the motorcycle is inclined during cornering. Further, the axial dimension of the elastic member 53 can be secured while suppressing the amount of protrusion, and the durability of the dynamic damper 50 can be improved.

Further, since the flange portion 51b of the hub 51 is fastened and fixed together by the fixing bolts 55 of the one-way clutch 42, it is not necessary to prepare additional parts, and an increase in the number of parts and a complicated structure can be avoided.

FIG. 4 is a diagram for explaining a dynamic damper according to an embodiment of the present invention.
The same reference numerals as those in FIG. 1 indicate the same or corresponding parts.

In the dynamic damper 60 of this embodiment, a tubular hub portion 61 is integrally formed on the boss portion 48b of the flange 48 of the one-way clutch 42, and the hub portion 6 is also formed.
1, the sleeve 62 is press-fitted to the outer peripheral surface of the ring 1, and the elastic member 63 is interposed between the outer peripheral surface of the sleeve 62 and the ring weight 64
It is configured by fixing. The hub portion 61 is fastened and fixed to the right end portion 11c of the crankshaft 11 with a bolt 55 via a washer 66. Further, the outer wheel 44 of the one-way clutch 42 is fastened to the flange 48 by a dish-shaped head bolt 65 screwed from the inner side in the axial direction thereof.

In this embodiment, since the hub portion 61 of the dynamic damper 60 is integrally formed with the boss portion 48b of the flange 48, the number of parts can be reduced and the cost of parts can be reduced as compared with the case where a hub is separately formed. Further, the dynamic damper 60 and the one-way clutch 42 can be integrated as an assembly, and the workability of assembling can be improved. Further, since the hub portion 61 is extended outward in the axial direction, the sleeve 6
The press-fitted area of 2 can be made large and slack due to vibration or the like can be prevented.

Further, since the outer wheel 44 is fixed by the bolts 65 screwed from the inside, the notches for avoiding the interference with the bolt heads on the ring weight as in the case where the bolts are screwed from the outside. Can be eliminated, and the inertial mass of the ring weight 64 can be correspondingly increased.

FIG. 5 is a view for explaining a dynamic damper according to an embodiment of the invention of claim 4, in which FIG.
The same reference numerals as those in FIG. 4 indicate the same or corresponding portions.

In the dynamic damper 70 of this embodiment, a sleeve 72 is fixed to the outer peripheral surface of a bottomed cylindrical hub 71, and a ring weight 74 is fixed to the outer peripheral surface of the sleeve 72 with an elastic member 73 interposed. It is configured. The tubular portion 71b of the hub 71 is press-fitted into the boss portion 48b of the one-way clutch 42, and the bottom portion 71a of the hub 71 is fastened and fixed to the end surface of the right end portion 11c of the crankshaft 11 by a bolt 55.

In this embodiment, the hub 71 of the dynamic damper 70 is pressed into the boss portion 48b and the hub 7 is
Since the bottom portion 71a of No. 1 is bolted and fixed to the crankshaft 11, the mounting strength of the dynamic damper 70 can be improved, and the slack of the dynamic damper 70 when the slack of the bolt 55 occurs can be avoided to prevent an adverse effect on the damper function. it can.

FIG. 6 is a view for explaining a dynamic damper according to an embodiment of the invention of claim 5, in which FIG.
The same reference numerals as those in FIG. 1 indicate the same or corresponding parts.

In the dynamic damper 80 of this embodiment, the ring weight 81 is axially extended so as to surround the body 81a extending in the radial direction along the inner surface of the cover case 82 and the outer periphery of the one-way clutch 42 from the body 81a. An extension portion 81b extending inward is integrally formed.

In this embodiment, the ring weight 81 is composed of the main body portion 81a and the large-diameter extension portion 81b that surrounds the outer peripheral portion of the one-way clutch 42, that is, the thicker portion is thickened. By increasing the mass of 81, the inertial mass of the weight 81 can be efficiently increased, and the damper function can be further improved. In this case, the outer peripheral portion 82a surrounding the extended portion 81b of the starter case 82 has a larger diameter than that in each of the above-described embodiments, but the larger diameter of the portion hinders securing the bank angle. It doesn't.

FIG. 7 is a diagram for explaining a dynamic damper according to an embodiment of the invention of claim 6, wherein:
The same reference numerals as those in FIG. 1 indicate the same or corresponding parts.

In the dynamic damper 90 of this embodiment, an elastic member 53 is fixed to the outer peripheral surface of the hub 51 via a sleeve 52, and a cylindrical iron ring weight 91 is fixed to the outer peripheral surface of the elastic member 53. A high specific gravity member 92 having a larger specific gravity than the weight 91 is fixed to the outer peripheral surface of the ring weight 91. As the high specific gravity member 92, for example, ambiloy can be adopted, and as a fixing method, press fitting, adhesion, or bolting and fixing can be adopted.

According to this embodiment, the iron ring weight 9
Since the high specific gravity member 92 such as ambiloy is fixed to 1, the inertial mass can be increased without changing the overall size of the dynamic damper 90, and the starter case 3
The dynamic damper 90 can be housed without changing the shape and size of 4. If the inertial mass is the same, the entire dynamic damper can be downsized.

[0044]

As described above, according to the crankshaft dynamic damper of the first aspect of the present invention, since the dynamic damper is separately arranged on the outer side of the one-way clutch of the crankshaft, it depends on the rotational force from the starter motor. The durability of the elastic member can be prevented from lowering, and the damper function can be reliably retained.

According to the second aspect of the present invention, the dynamic damper is arranged so that the hub main body overlaps with the boss portion of the one-way clutch. Therefore, the dynamic damper can be arranged by effectively utilizing the empty space at the end of the crankshaft. Since the amount of protrusion to the outside can be suppressed, the bank angle can be secured.

According to the third aspect of the present invention, since the hub portion of the dynamic damper is integrally formed with the boss portion of the outer wheel of the one-way clutch, the number of parts can be reduced and the dynamic damper can be made compact.

According to the fourth aspect of the present invention, since the tubular portion of the hub is press-fitted into the outer wheel and the bottom portion is bolted and fixed to the end face of the crankshaft, the mounting force of the dynamic damper can be improved and the bolt can be loosened. This has the effect of avoiding the slack of the dynamic damper when it occurs and preventing the effect on the damper function.

According to the fifth aspect of the present invention, since the weight is provided with the extension portion surrounding the outer peripheral portion of the one-way clutch,
This has the effect of increasing the inertial mass of the weight.

In the invention of claim 6, since at least a part of the weight is made of a material having a large specific gravity, there is an effect that the inertial mass can be increased without increasing the size.

[Brief description of drawings]

FIG. 1 is a sectional view for explaining a crankshaft dynamic damper according to an embodiment of the present invention.

FIG. 2 is a side view of an engine to which the dynamic damper of the above embodiment is applied.

FIG. 3 is a rear view of the engine of the embodiment.

FIG. 4 is a sectional view showing a dynamic damper according to an embodiment of the present invention.

FIG. 5 is a sectional view showing a dynamic damper according to an embodiment of the invention of claim 4;

FIG. 6 is a sectional view showing a dynamic damper according to an embodiment of the invention of claim 5;

FIG. 7 is a sectional view showing a dynamic damper according to an embodiment of the present invention.

FIG. 8 is a schematic view showing a conventional crankshaft dynamic damper.

[Explanation of symbols]

11 crankshaft 11c right end part (outer side part) 33 starter motor 42 one-way clutch 50, 60, 70, 80, 90 dynamic damper 51, 71 hub 51a hub body 51b flange part 53, 63, 73 elastic member 54, 64, 74, 81, 91, 92 Ring weight 61 Hub part

Claims (6)

[Claims] 1. A crankshaft dynamic damper for an engine, wherein the rotational force of a starter motor is transmitted to a crankshaft via a one-way clutch mounted at an end of the crankshaft. A crankshaft dynamic damper for an engine, which is arranged and fixed on a portion axially outside of the clutch. 2. The tubular weight according to claim 1, wherein a cylindrical weight is fitted and connected via an elastic member to an outer peripheral surface of a hub integrally formed with a radially extending flange portion on an inner peripheral surface of the cylindrical hub body. The hub body of the hub surrounds the boss portion of the output side outer wheel of the one-way clutch, and the flange portion is bolted and fixed to the end surface of the crankshaft. Axial dynamic damper. 3. A tubular hub portion is integrally formed on an output outer wheel of the one-way clutch according to claim 1, and a tubular weight is fitted and connected to an outer peripheral surface of the hub portion via an elastic member. A crankshaft dynamic damper for an engine, wherein the hub portion is fixed to an outer end portion of the crankshaft. 4. The weight according to claim 1, wherein a weight is fitted and connected to an outer peripheral surface of a bottomed tubular hub via an elastic member, and the tubular portion of the hub is the output side wheel of the one-way clutch. A crankshaft dynamic damper for an engine, which is press-fitted into a boss portion and has a bottom portion fixed to an end surface of a crankshaft by bolting. 5. The crankshaft dynamic damper for an engine according to claim 2, wherein the weight is formed with an extension portion surrounding an outer peripheral portion of the one-way clutch. 6. The crankshaft dynamic damper for an engine according to claim 2, wherein at least a part of the weight is made of a material having a larger specific gravity than the remaining part.