JP2020153458A - Fly wheel - Google Patents

Abstract

To inhibit whirl vibration of a fly wheel effectively.SOLUTION: A fly wheel 70 provided at a crank shaft 30 includes: a fly wheel body part 71 which is formed into a disc shape having a predetermined mass and has a through hole 79 into which the crank shaft 30 is inserted in an axial direction; and a connection mechanism 72 which connects the fly wheel body part 71 to a rear end part of the crank shaft 30 in a manner that the fly wheel body part 71 can swing around a shaft 74 perpendicular to the axial direction of the shaft 30 and includes a spring 76 which can elastically deform to absorb at least radial force transmitted from the crank shaft 30 to the fly wheel body part 71.SELECTED DRAWING: Figure 2

Description

The present disclosure relates to a flywheel, particularly to a flywheel provided on the crankshaft of an engine.

In general, a flywheel may be provided at the end of the crankshaft of an engine to stabilize the rotation of the crankshaft by inertial force.

While the engine is running, the crankshaft has a rotational force obtained by converting the linear motion due to the explosive force of each cylinder, a radial force that presses the crankpin toward the center of rotation, and a flywheel. Bending stress due to whirl vibration (a state in which the flywheel rotates while vibrating in a direction tilted from a plane orthogonal to the axial direction: hereinafter referred to as surface runout vibration) acts. When a large bending stress caused by these radial forces and surface runout vibrations acts on the crankshaft, it affects the life of the crankshaft, damages the bearings supporting the crankshaft, or There is a problem that the reaction force of the bending stress is transmitted to the cylinder block or the like, causing noise or the like.

For example, in Patent Document 1, a pair of masses are provided on the crank web and the counterweight closest to the flywheel to reduce the bending stress acting on the end of the crankshaft so as to damp the surface runout vibration of the flywheel. The technology is disclosed.

Further, in Patent Document 2, a concave groove is provided on the side surface of the flywheel main body in the circumferential direction, and the damper mass is accommodated in the concave groove via a spring member, and the surface of the flywheel is moved by the movement of the damper mass. A technique for attenuating runout vibration is disclosed.

Japanese Unexamined Patent Publication No. 3-244847 Japanese Unexamined Patent Publication No. 4-15336

By the way, in the structure described in Patent Document 1, masses are provided on the crank web and the counter weight, respectively. For this reason, the volume of the crankcase is inevitably large, which may lead to an increase in the size of the engine body including the cylinder block and the crankcase.

Further, in the structure described in Patent Document 2, the damper mass may interfere with the inner peripheral surface of the concave groove or the like as the damper mass moves. Therefore, the movement of the damper mass is restricted, so that the damping effect may not be sufficiently obtained.

The technique of the present disclosure aims to effectively suppress the surface vibration of the flywheel.

The technique of the present disclosure is a flywheel provided on a shaft, which is formed in a disk shape having a predetermined mass and has a through hole through which the shaft is inserted in the axial direction to project an end portion of the shaft. The flywheel body and the flywheel body are oscillatingly connected to the end of the shaft protruding from the through hole about an axis orthogonal to the axial direction of the shaft, and from the shaft. It is characterized by including a connecting mechanism having an elastic member that can absorb at least a radial force transmitted to the flywheel main body by elastically deforming.

Further, the shaft is a crankshaft of an engine having a plurality of cylinders, and the cylinder shaft of the cylinder is in a state where the piston of the cylinder closest to the flywheel main body is located at the top dead center among the plurality of cylinders. It is preferable that the shaft of the connecting mechanism is provided so as to be orthogonal to the direction in the axial direction of the crankshaft.

Further, the shaft has a stepped portion on the side opposite to the end portion with respect to the through hole, and the connecting mechanism serves as the shaft whose axis is orthogonal to the axial direction of the shaft. Pin member, a pin boss portion that supports the pin member at the end portion of the shaft, and a pair of rotatably supporting the pin member on one side surface of the flywheel main body portion on the side where the shaft protrudes. A yoke portion having an arm portion is provided, and the elastic member is interposed between the other side surface of the flywheel main body portion opposite to the one side surface and the stepped portion of the shaft. It is preferably formed of a flywheel.

Further, the shaft has a stepped portion on the side opposite to the end portion with respect to the through hole, and the connecting mechanism serves as the shaft whose axis is orthogonal to the axial direction of the shaft. The first axis and its axis are orthogonal to the axial direction of the shaft, and the spider having the second axis orthogonal to the first axis and the first axis can be rotated at the end of the shaft. A second yoke portion having a pair of shaft-supporting arm portions and a second arm portion having a pair of arm portions that rotatably support the second shaft on one side surface of the fly wheel main body on the protruding side of the shaft. A yoke portion is provided, and the elastic member is formed by a spring interposed between the other side surface of the fly wheel main body portion opposite to the one side surface and the stepped portion of the shaft. It is preferable that it is.

According to the technique of the present disclosure, it is possible to effectively suppress the surface vibration of the flywheel.

It is a schematic partial sectional view of the engine provided with the flywheel which concerns on 1st Embodiment. It is a schematic cross-sectional view which shows the flywheel which concerns on 1st Embodiment. It is a schematic cross-sectional view which shows the modification of the flywheel which concerns on 1st Embodiment. It is a schematic cross-sectional view which shows the modification of the flywheel which concerns on 1st Embodiment. It is a schematic diagram explaining the action effect of the flywheel which concerns on 1st Embodiment. It is a schematic cross-sectional view which shows the flywheel which concerns on 2nd Embodiment. It is a schematic cross-sectional view which shows the modification of the flywheel which concerns on 2nd Embodiment. It is a schematic cross-sectional view which shows the flywheel which concerns on another embodiment. It is a schematic cross-sectional view which shows the flywheel which concerns on another embodiment.

Hereinafter, the flywheel according to the present embodiment will be described with reference to the attached drawings. The same parts have the same reference numerals, and their names and functions are also the same. Therefore, detailed explanations about them will not be repeated.

[First Embodiment]
FIG. 1 is a schematic partial cross-sectional view of the engine 10 including the flywheel 70 according to the first embodiment.

As shown in FIG. 1, the engine 10 is, for example, an in-line 4-cylinder engine, and the engine main body 11 having a head cover 12, a cylinder head 13, a cylinder block 14, a crankcase 15, and an oil pan 16 in this order from the upper side. It has. The engine 10 is not limited to the in-line 4-cylinder engine shown in the illustrated example, and may be an in-line multi-cylinder engine other than the 4-cylinder engine, a V-type multi-cylinder engine, a horizontally opposed multi-cylinder engine, or a single-cylinder engine.

The cylinder block 14 is provided with a plurality of cylinders C1 to C4. Further, pistons P1 to P4 are housed in the cylinders C1 to C4 so as to be reciprocally movable. A small end portion of the connecting rod 22 is swingably connected to the pistons P1 to P4 via a piston pin 21. The combustion chamber is partitioned by the top surfaces of the pistons P1 to P4, the inner peripheral surfaces of the cylinders C1 to C4, and the lower surface of the cylinder head 13.

The cylinder head 13 is provided with injectors J1 to J4 for directly injecting fuel into the combustion chamber. Further, the cylinder head 13 is provided with an intake port (not shown) for introducing fresh air into the combustion chamber and an exhaust port (not shown) for drawing exhaust gas from the combustion chamber. The engine 10 is not limited to the direct injection engine shown in the illustrated example, and may be a premixed engine.

The engine 10 includes a crankshaft 30 rotatably supported between the cylinder block 14 and the crankcase 15.

More specifically, the crankshaft 30 is supported by a plurality of crankpins 31 to which connecting rods 22 are swingably connected to each other, and a bearing or the like (not shown) between the cylinder block 14 and the crankcase 15. A crank journal 32, a plurality of crank webs 33 connecting each crank pin 31 and each crank journal 32, and a plurality of counter weights 34 facing the crank web 33 with the rotation axis of the crankshaft 30 interposed therebetween. Is equipped with.

When the pistons P1 to P4 reciprocate in the cylinders C1 to C4 due to the explosive force in the combustion chamber, this reciprocating motion is transmitted from the connecting rod 22 to the crank pin 31 and converted into a rotary motion, and the crankshaft 30 moves the crank journal 32. It is designed to rotate around the axis.

The end portion 35 (end portion) of the crankshaft 30 is used as a part of a clutch device that transmits the rotational force of the crankshaft 30 to a transmission or the like (not shown) while stabilizing the rotation of the crankshaft 30 by an inertial force. A functioning flywheel 70 is provided. The flywheel 70 may constitute a device other than the clutch device, or may be provided as a single unit.

Hereinafter, the details of the flywheel 70 according to the first embodiment will be described.

FIG. 2 is a schematic cross-sectional view of the flywheel 70 according to the first embodiment, and FIGS. 2A and 2B show states in which the rotation angles of the crankshafts differ by 90 degrees.

As shown in FIGS. 2A and 2B, the flywheel 70 of the first embodiment has a substantially disk-shaped flywheel main body 71 having a predetermined mass and a central portion of the flywheel main body 71 as axes. A through hole 79 through which the end portion 35 of the crankshaft 30 is inserted while penetrating in the direction, and a flywheel main body 71 swing to a portion of the end portion 35 of the crankshaft 30 that protrudes rearward from the through hole 79. It is provided with a connecting mechanism 72 for connecting as possible.

The connecting mechanism 72 includes a pin boss portion 73, a pin member 74, a yoke portion 75, and a spring 76 as an elastic member.

The pin boss portion 73 is provided so as to project from the rear end surface of the terminal portion 35 of the crankshaft 30 toward the opposite side (rear) of the flywheel main body portion 71 with a predetermined length in the axial direction. The pin member 74 is arranged so that its axial center is orthogonal to the axial direction of the crankshaft 30 (including the axial direction of the crankpin 31 shown in FIG. 1). The pin member 74 is preferably supported by a pin boss portion 73 at a substantially intermediate position in the axial direction thereof.

The yoke portion 75 projects a pair of arm portions 75A and 75B (see FIG. 2B) that protrude rearward from the rear side surface of the flywheel main body portion 71 at a predetermined length in the axial direction and are separated from each other. I have. Both ends of the pin member 74 protruding from the pin boss portion 73 are rotatably supported on the pair of arm portions 75A and 75B, respectively.

That is, the flywheel main body 71 can rotate integrally with the rear end surface of the end portion 35 of the crankshaft 30 protruding from the through hole 79 in the circumferential direction via the connecting mechanism 72, and is orthogonal to the axis of the crankshaft 30. The pin member 74 is oscillatingly connected in two directions around the pin member 74.

When the flywheel main body 71 functions as a part of the clutch device, as shown in FIG. 3A, the pilot bearing 110 that pivotally supports the transmission input shaft 100 is the arm portions 75A and 75B. It may be attached to the disk portion 120 provided at the protruding end. Alternatively, as shown in FIG. 3B, the pilot bearing 110 may be attached to the disk portion 130 provided at the protruding end of the pin boss portion 73.

Returning to FIG. 2, the spring 76 is provided between the crankshaft 30 and the flywheel main body 71. Specifically, of the end portion 35 of the crankshaft 30, a stepped portion 36 (or flange) having a rear side surface facing the front side surface of the flywheel main body portion 71 at a portion on the front side of the through hole 79. Is provided. The spring 76 is interposed between the rear side surface of the stepped portion 36 facing each other and the front side surface of the flywheel main body portion 71 in a compressed state.

The spring 76 is preferably attached so that the side surface of the flywheel body 71 is balanced so as to be orthogonal to the axial direction of the crankshaft 30 in a stationary state. The number of springs 76 is not limited to one, and for example, as shown in FIG. 4, a plurality of springs 76 may be arranged at a predetermined pitch in the circumferential direction. However, also in this case, it is desirable to balance the side surface of the flywheel main body 71 so as to be orthogonal to the axial direction of the crankshaft 30 in a stationary state.

In the present embodiment, the pin member 74 supports the axis (or the pin member 74) of the piston P4 (see FIG. 1) of the cylinder C4 closest to the flywheel 70 when it is located near the compression top dead center. The arm portions 75A and 75B of the yoke portion 75 are provided so as to be substantially orthogonal to the cylindrical axial direction of the cylinder C4 (reciprocating movement direction of the piston P4) in the axial direction of the crankshaft 30. Here, it is desirable that the rigidity of the spring 76 is set so as to be a bending natural vibration of the end portion 35 of the crankshaft 30, which is lower than the lowest frequency excited from the piston side. Further, it is desirable that the spring 76 applies an initial load at the time of mounting so that the tension is always transmitted to the crankshaft 30 and the flywheel main body 71 even during rotation.

The action and effect of the flywheel 70 according to the first embodiment configured as described above will be described with reference to FIG.

As shown in FIG. 5, when the cylinder C4 explodes in a state where the piston P4 of the cylinder C4 closest to the flywheel 70 is located near the compression top dead center, the crank pin 31 is shown via the connecting rod 22. When the force indicated by the middle arrow F acts, the bending stress M1 that deforms the crankshaft 30 as shown by the broken line X1 in the figure acts on the crankpin 31 and the crankweb 33. Further, on the end portion 35 of the crankshaft 30, forces M2 and 3 in the surface runout direction (substantially radial direction) for causing the flywheel main body portion 71 to runout and vibrate as shown by broken lines X2 and 3 in the figure act. To do.

In the present embodiment, the flywheel body 71 of the flywheel 70 is connected to the rear end surface of the end 35 of the crankshaft 30 including a pin member 74 orthogonal to the axial direction of the crankshaft 30 (and the crankpin 31). It is swingably connected via a mechanism 72, and an elastically deformable spring 76 is interposed between the terminal portion 35 of the crankshaft 30 and the flywheel main body portion 71.

That is, with respect to the force M2 in the runout direction acting on the flywheel body 71 from the end 35 of the crankshaft 30, and the force M3 in the runout direction acting on the flywheel body 71 from the end 35 of the crankshaft 30. Therefore, the spring 76 is configured to be able to effectively absorb or dampen the forces M2 and 3 in the surface runout direction by appropriately elastically compressing the spring 76.

As a result, the surface runout vibration of the flywheel main body 71 is surely suppressed, and further, the bending stress and vibration of the crankshaft 30 caused by the surface runout vibration and the like are surely reduced, and the crankshaft 30 is surely reduced. (For example, breakage of the boundary portion A between the crank web 33 and the crank journal 32 closest to the flywheel 70, breakage of the boundary portion B between the crank web 33 and the crank pin 31, etc.) can be effectively suppressed. Will be possible. Further, by suppressing the surface vibration of the flywheel main body 71, it is possible to effectively reduce the noise caused by the vibration.

Further, by arranging the connecting mechanism 72 behind the flywheel main body 71 without arranging it between the engine 10 and the flywheel main body 71, the flywheel main body 71 is adjacent to the rear end of the engine 10. The total length of the engine 10 in the crankshaft direction can be effectively shortened.

[Second Embodiment]
FIG. 6 is a schematic cross-sectional view showing the flywheel 80 according to the second embodiment.

As shown in FIG. 6, in the flywheel 80 of the second embodiment, a disk-shaped flywheel main body 81 having a predetermined mass is attached to the rear end surface of the terminal 35 of the crankshaft 30 with a universal joint 82 (an example of a connecting mechanism). ) Are connected.

Specifically, the flywheel main body 81 is provided with a through hole 89 through which the terminal 35 of the crankshaft 30 is inserted, as in the first embodiment. Further, the universal joint 82 projects from the rear end surface of the end portion 35 of the crankshaft 30 toward the opposite side (rear side) of the flywheel main body portion 81 by a predetermined length in the axial direction, and is separated from each other and faces each other. The first yoke portion 83 having the arm portions 83A and 83B (see FIG. 6 (B)), the spider 84 having the first axis 84A and the second axis 84B (see FIG. 6 (A)) orthogonal to each other, A second yoke 85 having a pair of arm portions 85A and 85B that protrude rearward from the rear side surface of the flywheel main body portion 81 by a predetermined length in the axial direction and are separated from each other and face each other is provided.

The spider 84 is arranged so that the axes of the first and second axes 84A and 84B are orthogonal to the axial direction of the crankshaft 30 (including the axial direction of the crankpin 31 shown in FIG. 1). Each of the arm portions 83A and 83B of the first yoke portion 83 rotatably supports both ends of the first shaft 84A of the spider 84. Each of the arm portions 85A and 85B of the second yoke portion 85 rotatably supports both ends of the second shaft 84B of the spider 84.

That is, the flywheel main body 81 can rotate integrally with the rear end surface of the end portion 35 of the crankshaft 30 via the universal joint 82 in the circumferential direction, and the two first wheels are orthogonal to the axis of the crankshaft 30. And the second shafts 84A and 84B are oscillatingly connected in four directions.

Similar to the first embodiment, the spring 86 is interposed between the rear side surface of the stepped portion 36 of the crankshaft 30 and the front side surface of the flywheel main body portion 81 in a compressed state. The spring 86 is preferably attached so that the side surface of the flywheel main body 81 is in a stationary state and is balanced so as to be orthogonal to the axial direction of the crankshaft 30. The number of springs 86 is not limited to one, and for example, as shown in FIG. 7, a plurality of springs 86 may be arranged at a predetermined pitch in the circumferential direction. However, also in this case, it is desirable to balance the side surface of the flywheel main body 81 so that it is orthogonal to the axial direction of the crankshaft 30 in a stationary state.

In the present embodiment, the spider 84 pivotally supports the axis of the first axis 84A (or the first axis 84A) when the piston P4 of the cylinder C4 closest to the fly wheel 80 is located near the compression top dead point. The arm portions 83A and 83B of the first yoke portion 83 (opposing directions) are orthogonal to the cylinder axial direction of the cylinder C4 in the axial view of the crankshaft 30, and the piston P3 of the cylinder C3 which is the second closest to the fly wheel 80 ( When the (piston whose phase is about 180 degrees different from that of the piston P4) is located near the compression top dead point, the axis of the second axis 84B should be orthogonal to the axial direction of the cylinder C3 in the axial view of the crankshaft 30. It is provided in. Here, it is desirable that the rigidity of the spring 86 is set so as to be a bending natural vibration of the end portion 35 of the crankshaft 30, which is lower than the lowest frequency excited from the piston side. Further, it is desirable that the spring 86 applies an initial load at the time of mounting so that the tension is always transmitted to the crankshaft 30 and the flywheel main body 81 even during rotation.

That is, when the cylinder C4 explodes with the piston P4 located near the compression top dead center, the force acting on the flywheel main body 81 from the end portion 35 of the crankshaft 30 and the piston. When the cylinder C3 explodes while P3 is located near the compression top dead center, the spring 86 responds to the force acting on the flywheel body 81 from the end portion 35 of the crankshaft 30 in the surface runout direction. Is configured to be able to effectively absorb or dampen the force in the runout direction by elastically deforming.

As a result, the surface runout vibration of the flywheel main body 81 is surely suppressed, and further, the bending stress and vibration of the crankshaft 30 caused by the surface runout vibration and the like are surely reduced. Similar to the form, it is possible to effectively suppress damage to the crankshaft 30 and the like. Further, by suppressing the surface vibration of the flywheel main body 81, it is possible to effectively reduce the noise caused by the vibration.

[Other]
It should be noted that the present disclosure is not limited to the above-described embodiment, and can be appropriately modified and implemented without departing from the gist of the present disclosure.

For example, the springs 76 and 86 of the above embodiment are elastically deformable mesh material 90 as shown in FIG. 8, or elastically deformable leaf spring 91 and other elastic members as shown in FIG. It may be configured by replacing with.

Further, the scope of application of the present disclosure is not limited to the crankshaft 30 of the engine 10, and can be widely applied to the rotating system of other devices.

10 Engine 11 Engine body 12 Head cover 13 Crankshaft 14 Crankcase block 15 Crankcase 16 Oil pan C1 to C4 Cylinder P1 to P4 Piston 21 Piston pin 22 Connecting rod 30 Crankshaft 31 Crankpin 32 Crankjour 33 Crankweb 34 Counterweight 35 End (end)
70 Flywheel 71 Flywheel body 72 Connecting mechanism 73 Pin boss 74 Pin member 75 Yoke 76 Spring (elastic member)
79 Through hole 80 Flywheel 81 Flywheel body 82 Universal joint (connecting mechanism)
83 1st yoke part 84 Spider 85 2nd yoke part 86 Spring (elastic member)
89 through hole

Claims (4)

A flywheel installed on the shaft
A flywheel main body that is formed in a disk shape having a predetermined mass and has a through hole through which the shaft is inserted in the axial direction to project the end of the shaft.
The flywheel main body is oscillatingly connected to the end of the shaft protruding from the through hole about an axis orthogonal to the axial direction of the shaft, and from the shaft to the flywheel main body. A flywheel characterized by comprising a connecting mechanism having an elastic member that can absorb at least the transmitted radial force by elastically deforming. The shaft is a crankshaft of an engine having a plurality of cylinders.
Among the plurality of cylinders, the shaft of the connecting mechanism is in the axial direction of the crankshaft with respect to the cylinder axis direction of the cylinder in a state where the piston of the cylinder closest to the flywheel main body is located at the top dead center. The flywheel according to claim 1, which is provided so as to be orthogonal to each other visually. The shaft has a stepped portion on the side opposite to the end portion with respect to the through hole.
The connecting mechanism includes a pin member as the shaft whose axial center is orthogonal to the axial direction of the shaft, a pin boss portion that supports the pin member at the end portion of the shaft, and the flywheel main body portion. A yoke portion having a pair of arm portions that rotatably support the pin member is provided on one side surface on the side on which the shaft protrudes.
The elastic member according to claim 1 or 2, wherein the elastic member is formed by a spring interposed between the other side surface of the flywheel main body portion opposite to the one side surface and the stepped portion of the shaft. The flywheel described. The shaft has a stepped portion on the side opposite to the end portion with respect to the through hole.
The connecting mechanism has a first axis as the axis whose axis is orthogonal to the axial direction of the shaft, and a second axis whose axis is orthogonal to the axial direction of the shaft and orthogonal to the first axis. A spider having a shaft, a first yoke portion having a pair of arm portions that rotatably support the first shaft at the end portion of the shaft, and one of the fly wheel main body portions on the side on which the shaft protrudes. A second yoke portion having a pair of arm portions that rotatably support the second shaft is provided on a side surface thereof.
The elastic member according to claim 1 or 2, wherein the elastic member is formed by a spring interposed between the other side surface of the flywheel main body portion opposite to the one side surface and the stepped portion of the shaft. The flywheel described.

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