Damper device

Abstract

A cylindrical section (32) extends in the axial direction from the inner circumferential edge of a disc section (31) of a bush (21), and is interposed between the inner circumferential end edge (12a) of a retaining plate (12) and the outer peripheral surface of a boss part (14). Dimensions of the cylindrical section (32) are set so as to limit the deflection angle of the central axis within a prescribed range when the boss part (14) is inclined. When the boss part (14) is inclined during the step for connecting to a gear box, the cylindrical section (32) is sandwiched between the inner circumferential end edge (12a) of the retaining plate (12) and the boss part (14), thereby limiting the deflection angle of the central axis. Dimensions of a claw section (33) are set such that a bending stress with the maximum deflection angle does not cause breakage.

Description

Technical Field

[0001] This invention relates to a damper device provided, for example, between an engine (internal combustion engine) and a transmission.

Background Art

[0002] For example, between an engine and a transmission of an automobile, a damper device that transmits torque and absorbs / dampens torsional vibrations is often provided. As disclosed in Patent Document 1, this type of damper device includes an input-side rotating member to which torque is input from the engine, an output-side rotating member that is combined with the input-side rotating member so as to be relatively rotatable, and a plurality of coil springs arranged along the rotation tangential direction between the input-side rotating member and the output-side rotating member.

[0003] Furthermore, in the damper device of Patent Document 1, as a friction generating mechanism that generates frictional torque with respect to the relative rotation between the input-side rotating member and the output-side rotating member, a configuration is disclosed in which a bush that slidably contacts a spline hub serving as the output-side rotating member is axially biased by an annular cone spring. The bush includes a plurality of claw portions that project radially outward, and by engaging these claw portions with recesses of a second bush in a second friction generating mechanism on the outer peripheral side, positioning in the rotational direction with respect to the input-side rotating member is achieved.

[0004] For example, when assembling an engine and a transmission, the input shaft of the transmission may be inserted in a state inclined with respect to the spline hub. When the central axis of the output-side rotating member is inclined with respect to the central axis of the input-side rotating member in this way, the bush inclines together with the spline hub, and there is a concern that the tip portion of the claw portion on the outer periphery is axially pushed by the second bush and the claw portion breaks at the root portion.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

[0006] This invention is A first rotating member and A second rotating member having a boss portion at its center and arranged to be rotatable relative to the first rotating member, A spring member for elastically connecting the first rotating member and the second rotating member in the rotational direction, A friction generating mechanism that generates friction torque with respect to the relative rotation between the first rotating member and the second rotating member, A damper device equipped with, The above friction generation mechanism is, An annular bush is positioned on the outer circumference of the boss portion so as to be rotatable relative to the boss portion, with its end face in contact with the annular friction surface of the second rotating member, A retaining plate forming part of the first rotating member that faces the bush in the axial direction, An annular cone spring is positioned in a compressed state between the bush and the retaining plate to bias the bush toward the annular friction surface, Equipped with, The above bushing is A disc portion located between the above-mentioned annular friction surface and the above-mentioned cone spring, A cylindrical portion extending axially from the inner peripheral edge of the disc portion so as to be interposed between the inner peripheral edge of the retrieving plate and the outer peripheral surface of the boss portion, Multiple claw portions protruding radially outward at multiple locations on the outer edge of the disc portion, Equipped with, The claw portion engages with an engagement recess provided on an annular member that rotates integrally with the first rotating member. When the central axis of the boss portion is tilted with respect to the central axis of the first rotating member, the cylindrical portion is sandwiched between the inner circumferential edge of the retaining plate and the boss portion, thereby limiting the angle of inclination so that the claw portion does not experience bending stress that would lead to breakage.

[0007] According to this invention, even if the central axis of the boss portion is tilted relative to the central axis of the first rotating member due to an external force during assembly, for example, the magnitude of the tilt is limited, thereby suppressing breakage of the claw portion. [Brief explanation of the drawing]

[0008] [Figure 1] A cross-sectional view showing the main parts of a damper device according to one embodiment. [Figure 2] A cross-sectional view showing an enlarged view of the bushing portion in Figure 1. [Figure 3] Plan view of a single bushing. [Figure 4] Cross-sectional view along line AA in Figure 3. [Figure 5] An explanatory diagram showing what happens when the hub component is tilted during the process of connecting the engine and the gearbox. [Modes for carrying out the invention]

[0009] An embodiment of this invention will be described below with reference to the drawings. The overall configuration of the damper device is a known configuration as disclosed in Patent Document 1, so it will be described briefly, but it includes, for example, an input-side rotating member 1 attached to the flywheel at the rear end of the engine to which the engine torque is input, and an output-side rotating member 2 that is combined to rotate relative to the input-side rotating member 1. The output-side rotating member 2 mainly consists of, for example, a spline hub 3 to which the input shaft of a gearbox connected to the engine is spline coupled. Note that the left side of Figure 1 is the engine side and the right side is the gearbox side.

[0010] The engine shown in the illustration is a power generation engine in a series hybrid vehicle, and its rotational speed is increased by a gearbox, which drives a motor-generator connected to the gearbox.

[0011] The input-side rotating member 1 is formed in a disc shape by joining the outer peripheries of a roughly circular input plate 11 located on the engine side and a roughly circular retaining plate 12 located on the gearbox side, and the output-side rotating member 2, a spline hub 3, is sandwiched between these two plates. Multiple coil springs 4, for example four, are arranged along the rotational tangential direction to elastically connect the two in the rotational direction. Torsional vibrations are absorbed by the elastic force of these coil springs 4.

[0012] In this illustrated example, the spline hub 3 is divided into a central hub member 13 including a cylindrical boss portion 14 and an outer flange member 15, similar to the configuration disclosed in, for example, Japanese Patent Application Publication No. 2022-095172. The hub member 13 and the flange member 15 are combined so as to be able to rotate relative to each other by a predetermined small angle through the meshing of teeth (not shown), and a sub-coil spring 18 is provided between them along the rotational tangential direction. Specifically, the hub member 13 has a boss flange 16 that protrudes outward from the outer circumferential surface of the boss portion 14 near the axial center, and the outer circumferential surface of this boss flange 16 is provided with the teeth described above. The flange member 15 has an opening 17 through which the boss flange 16 passes, and the inner circumferential surface of this opening 17 is provided with teeth corresponding to the teeth on the boss flange 16 side. A small gap is provided in the rotational direction between the teeth of the two meshing parts, and they are biased in the rotational direction by the sub-coil spring 18. This structure allows minute torque fluctuations to be absorbed in the spline hub 3.

[0013] The four coil springs 4 described above, which elastically connect the input-side rotating member 1 and the output-side rotating member 2, are interposed between the outer flange member 15 and the input-side rotating member 1 in the spline hub 3.

[0014] Furthermore, the present invention is also applicable to damper devices in which the spline hub 3 is not divided into a hub member 13 and a flange member 15.

[0015] In the illustrated damper device, as a friction generating mechanism that generates a frictional torque serving as a damping force with respect to the relative rotation between the input-side rotating member 1 and the output-side rotating member 2, there are provided a first friction generating mechanism 5 that functions between the input-side rotating member 1 and the hub member 13 of the spline hub 3, and a second friction generating mechanism 6 that functions between the input-side rotating member 1 and the flange member 15 of the spline hub 3. The first friction generating mechanism 5 and the second friction generating mechanism 6 are provided on both axial sides (engine side and gearbox side) of the spline hub 3, respectively. Hereinafter, the configuration of the friction generating mechanisms 5 and 6 on the gearbox side, which is the main part of the present invention, will be described, and the description of the friction generating mechanism on the engine side will be omitted.

[0016] As shown in FIG. , the first friction generating mechanism 5 includes an annular bush 21 made of a hard synthetic resin such as so-called engineering plastic, and an annular cone spring 22 disposed in a compressed state between the bush 21 and the retaining plate 12.

[0017] The bush 21 is rotatably fitted to the outer peripheral surface of the boss portion 14 of the hub member 13 of the spline hub 3, and an annular friction surface 21a serving as an axial end surface is in contact with an annular friction surface 16a formed by the end surface of the boss flange 16 of the hub member 13. When the input-side rotating member 1 and the output-side rotating member 2 (hub member 13) rotate relative to each other, frictional torque is generated by their sliding contact.

[0018] As shown in FIG. , the bush 21 has a disk portion 31 located between the boss flange 16 and the cone spring 25, and a cylindrical tubular portion 32 extending from the inner peripheral edge of the disk portion 31 toward the gearbox side, whereby the overall cross section is substantially L-shaped. The cone spring 7 is fitted to the outer periphery of the tubular portion 32 and is positioned in the radial direction by the tubular portion 32.

[0019] The inner circumference portion of the retaining plate 12 faces the bush 21 in the axial direction, and the cone spring 22 is positioned between them. The inner circumferential edge 12a of the retaining plate 12 is located slightly further outward than the cylindrical portion 32 of the bush 21, and the two overlap in the axial direction.

[0020] The cone spring 22 has a tapered cross-sectional shape that is inclined at a relatively small angle with respect to the plane perpendicular to the axis. Due to this inclination of the cross-section, the inner circumference of the cone spring 22 presses against the bush 21 in the axial direction, and the outer circumference presses against the inner surface of the retaining plate 12 in the axial direction. The cone spring 22 biases the bush 21 in the axial direction toward the boss flange 16, resulting in a state where the annular friction surfaces 21a and 16a are in proper contact with each other.

[0021] The second friction generating mechanism 6 is located on the outer circumference of the first friction generating mechanism 5 and comprises a second bush 24 made of hard synthetic resin and an annular second cone spring 25 positioned in a compressed state between the second bush 24 and the retaining plate 12. The second bush 24 has a suitable lining (not shown) attached to the surface facing the flange member 15, and contacts the end face of the flange member 15 through this lining. The second bush 24 is biased toward the flange member 15 by the second cone spring 25, and a suitable friction torque is generated between the second bush 24 and the flange member 15 by the biasing force of the second cone spring 25.

[0022] The second bush 24 has a projection 24a on its back surface, which engages with the opening 28 of the retrieval plate 12. As a result, the second bush 24 can move axially relative to the retrieval plate 12, but its movement in the rotational direction (circumferential direction) is restricted. In other words, the engagement of the projection 24a causes the retrieval plate 12 and the second bush 24 to rotate together as a single unit.

[0023] In the first friction generating mechanism 5, the bush 21 has a claw portion 33 extending radially outward from the outer edge of the disc portion 31, and this claw portion 33 engages with an engagement recess 41 provided on the back surface of the second bush 24. This engagement restricts the relative rotation of the bush 21 with respect to the second bush 24, and consequently, restricts the relative rotation of the bush 21 with respect to the retaining plate 12.

[0024] Figure 3 is a plan view of the bush 21 from the retaining plate 12 side, and Figure 4 is a cross-sectional view along line AA in Figure 3. Note that Figure 1, mentioned above, also corresponds to a cross-section along line AA. As described above, the bush 21 comprises a disc portion 31 located between the boss flange 16 and the cone spring 25, a cylindrical portion 32 extending axially from the inner peripheral edge of the disc portion 31, and a plurality of claw portions 33 protruding radially outward at multiple locations on the outer peripheral edge of the disc portion 31, and these are integrally molded from a hard synthetic resin.

[0025] In one embodiment, the claw portions 33 are provided at a total of four locations at 90° intervals, as shown in Figure 3, and each portion forms a rectangle in the plan view shown in Figure 3. In addition, adjacent to both sides of each claw portion 33, approximately semicircular notches 34 are formed on the outer edge of the disc portion 31, receding radially inward. By providing a pair of notches 34 on both sides of the claw portion 33 in this way, stress concentration at the base of the claw portion 33 when the tip of the claw portion 33 is pressed in the axial direction is alleviated.

[0026] Furthermore, as shown in Figure 4, the axial thickness of the claw portion 33 is such that the axial thickness at the radially outer tip portion is thinner compared to the axial thickness at the base portion. In other words, it has a cross-sectional shape that becomes thinner from the radially inner to the radially outer portion. To put it another way, the axial thickness at the tip portion of the claw portion 33 is thinner than the thickness of the disc portion 31. It should also be possible to have a configuration in which the thickness changes in steps in several stages. And, as shown in Figure 4, the radially outer tip of the claw portion 33 is located closer to the retrieval plate 12 than the plane along the annular friction surface 21a of the disc portion 31.

[0027] Furthermore, the radial length of the claw portion 33 is set to be as short as possible within the range that allows the bush 21 to be positioned in the rotational direction.

[0028] As shown in Figure 2, the cylindrical portion 32 of the bush 21 extends axially from the inner edge of the disc portion 31 toward the gearbox, interposed between the inner edge 12a of the retaining plate 12 and the outer surface of the boss portion 14. The dimensions of each part of this cylindrical portion 32 are set with the intention of limiting the tilt of the boss portion 14 when the boss portion 14 is tilted during assembly of the engine and gearbox, that is, the angle of deviation of the central axis (center line) of the boss portion 14 with respect to the central axis (center line) of the input side rotating member 1.

[0029] In other words, the engine and gearbox are ultimately assembled with their central axes aligned in a straight line, and in the completed state, the cylindrical portion 32 does not come into contact with the inner circumferential edge 12a of the retaining plate 12. That is, as shown in Figure 2, a small gap exists between the outer circumferential surface of the cylindrical portion 32 and the inner circumferential edge 12a of the retaining plate 12.

[0030] However, during the assembly process between the engine and the gearbox, particularly when inserting the splined input shaft end from the gearbox into the boss portion 14 of the hub member 13 for spline coupling, the input shaft may be pushed into the boss portion 14 at a slight angle. Since the gearbox for series hybrid vehicles is smaller and shorter in overall length compared to a typical transmission, it can be assembled to the engine manually by an operator. Therefore, the phenomenon of attempting to insert the input shaft at an angle is more likely to occur. In such cases, the boss portion 14 (hub member 13) temporarily tilts as the input shaft is inserted. As a result, the bush 21 fitted to the boss portion 14 tilts relative to the second bush 24, causing the tip of the claw portion 33 to interfere with the bottom surface of the engagement recess 41, generating stress at the base and potentially causing the claw portion 33 to break. In particular, in the configuration where the spline hub 3 is divided into a central hub member 13 and an outer flange member 15, as in the above embodiment, only the hub member 13 having the boss portion 14 is prone to tilting.

[0031] To avoid breakage of the claw portion 33, in the above embodiment, the cylindrical portion 32 limits the maximum deviation angle of the central axis to a certain value. Figure 5 is an explanatory diagram of when the hub member 13 is temporarily tilted during the process of connecting the engine and the gearbox. This corresponds to a state in which the input shaft on the gearbox side is slightly inserted into the spline hole of the boss portion 14. As shown in the figure, when the central axis of the hub member 13 tilts with respect to the central axis of the input-side rotating member 1, the cylindrical portion 32 interposed between the inner circumferential edge 12a of the retaining plate 12 and the outer circumferential surface of the boss portion 14 is sandwiched between them. Since the cylindrical portion 32 is made of a sufficiently hard material, the distance between the inner circumferential edge 12a of the retaining plate 12 and the outer circumferential surface of the boss portion 14 is secured by the sandwiching of the cylindrical portion 32, and as a result, the deviation angle of the central axis of the hub member 13 is limited.

[0032] On the other hand, the dimensions and positional relationship of the claw portion 33 are set so that bending stress leading to breakage does not occur under the maximum angle of deviation defined by the cylindrical portion 32. For example, as mentioned above, the tip portion of the claw portion 33 is thin-walled and is located further away from the retaining plate 12 than the plane along the annular friction surface 21a of the disc portion 31, so that interference with the bottom surface of the engagement recess 41 is less likely to occur when the bush 21 is tilted relative to the second bush 24 as shown in Figure 5. Similarly, the short radial length of the claw portion 33 makes interference with the bottom surface of the engagement recess 41 less likely to occur. Furthermore, while the tip portion of the claw portion 33 is thin-walled, the base portion connected to the disc portion 31 is sufficiently thick, so that breakage is less likely to occur even when pressed by the bottom surface of the engagement recess 41.

[0033] Therefore, even if the gearbox is connected to the engine at a slight angle due to manual handling by an employee, for example, breakage of the claw portion 33 of the bush 21 can be reliably prevented. Note that the tilt of the hub member 13 is a temporary phenomenon that occurs during the assembly process, and when the engine and gearbox housing are finally firmly fixed together, it returns to the normal state shown in Figure 2.

[0034] Although one embodiment of the present invention has been described in detail above, the present invention is not limited to the above embodiment, and various modifications are possible. For example, the damper device of the present invention is not limited to gearboxes for series hybrid vehicles, but can also be applied to vehicles that run on engine output in which the input shaft of the transmission is connected to the boss portion, and may also be configured in which the damper device is attached to the clutch disc, as in a manual transmission. Furthermore, the engagement recess into which the claw portion of the bush engages may be provided by a component other than the second bush 24 described above. Moreover, as mentioned above, the spline hub 3 may not be divided into a hub member 13 and a flange member 15.

Claims

1. A first rotating member and A second rotating member having a boss portion at its center and arranged to be rotatable relative to the first rotating member, A spring member for elastically connecting the first rotating member and the second rotating member in the rotational direction, A friction generating mechanism that generates friction torque with respect to the relative rotation between the first rotating member and the second rotating member, A damper device equipped with, The above friction generation mechanism is, An annular bush is positioned on the outer circumference of the boss portion so as to be rotatable relative to the boss portion, with its end face in contact with the annular friction surface of the second rotating member, A retaining plate forming part of the first rotating member that faces the bush in the axial direction, An annular cone spring is positioned in a compressed state between the bush and the retaining plate to bias the bush toward the annular friction surface, Equipped with, The above bushing is A disc portion located between the above-mentioned annular friction surface and the above-mentioned cone spring, A cylindrical portion extending axially from the inner peripheral edge of the disc portion so as to be interposed between the inner peripheral edge of the retrieving plate and the outer peripheral surface of the boss portion, Multiple claw portions protruding radially outward at multiple locations on the outer edge of the disc portion, Equipped with, The claw portion engages with an engagement recess provided on an annular member that rotates integrally with the first rotating member. When the central axis of the boss portion is tilted with respect to the central axis of the first rotating member, the cylindrical portion is sandwiched between the inner circumferential edge of the retaining plate and the boss portion, thereby limiting the angle of inclination so that the claw portion does not experience bending stress that would lead to breakage. Damper device.

2. The above-mentioned annular member is a second bush in a second friction generating mechanism configured on the outer circumference side of the above-mentioned friction generating mechanism. The damper device according to claim 1.

3. The above bush is formed by integrally creating the disc portion, the cylindrical portion, and the claw portion from a hard synthetic resin. The damper device according to claim 1.

4. The first rotating member described above is attached to the flywheel at the rear end of the engine. The second rotating member described above includes a spline hub with splines on the inner circumference of the boss portion, The input shaft of the gearbox, which is connected to the rear end of the engine, is inserted into the boss portion. The damper device according to claim 1.

5. The above-mentioned claw portion is formed with a thinner axial thickness at the radially outer tip portion compared to the axial thickness at the base portion. The damper device according to claim 1.

6. The radial length of the claw portion is configured to be short so that the claw portion does not break under the maximum angle of deviation limited by the cylindrical portion. The damper device according to claim 1.

7. A notch is formed on the outer edge of the disc portion adjacent to the claw portion, which is recessed radially inward. The damper device according to claim 1.

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