Damping device

Abstract

A friction generating mechanism (1) of a vibration damper has a sleeve (6) which contacts with an annular friction surface (4c) of a splined hub (4), and a coned spring (7) which is arranged in a compressed state between a baffle (5) and the sleeve (6). A first load support surface (9) of the sleeve (6) and a second load support surface (10) of the baffle (5) have stepped portions (9a, 10a) which retreat in a manner to respectively accommodate an outer peripheral edge (7b) and an inner peripheral edge (7a) when the coned spring (7) is turned in opposite directions. The radial positions of boundaries (9c, 10c) of the stepped portions (9a, 10a) are formed in a relationship of D1>D2, so that the coned spring (7) is not reversed even if an excessive axial load is input.

Description

Technical Field

[0001] The present invention relates to a vibration damping device, for example, disposed between an internal combustion engine and a transmission. Background Technology

[0002] For example, most automobiles have a damping device between the internal combustion engine and the transmission that transmits torque and absorbs / damps torsional vibrations. As disclosed in Patent Document 1, such a damping device has: an input-side rotating component that receives torque from the internal combustion engine; an output-side rotating component that is combined with the input-side rotating component in a rotatable manner; and a plurality of helical springs that are arranged tangentially between the input-side and output-side rotating components.

[0003] Furthermore, in the vibration damping device of Patent Document 1, a friction generating mechanism that generates friction torque by relative rotation with respect to the input-side rotating component and the output-side rotating component is disclosed, wherein a sleeve that slides in sliding contact with the splined hub that becomes the output-side rotating component is pre-tightened in the axial direction by using an annular conical spring.

[0004] Patent Document 1 describes a conical spring with a small, inclined conical cross-section, positioned axially with its inner periphery near the sleeve and its outer periphery near the baffle. With this structure, for example, when the splined hub is subjected to a very large axial load and the conical spring displaces in a flattened manner, the conical spring may reverse in the opposite direction to its original conical orientation. More specifically, this reversal phenomenon is not considered in the positions of the force applied by the baffle pressing the conical spring and the force applied by the sleeve pressing the conical spring in the opposite direction.

[0005] Patent Document 1: Japanese Patent Application Publication No. 2003-074636 Summary of the Invention

[0006] The vibration damping device of the present invention includes: a first rotating member; a second rotating member; a spring member that elastically connects the two; and a friction generating mechanism that generates frictional torque for relative rotation. The friction generating mechanism includes: a sleeve that contacts the annular friction surface of the second rotating member; a baffle that is a part of the first rotating member that is axially opposite to the sleeve; and an annular conical spring that is disposed between the two in a compressed state to preload the sleeve toward the annular friction surface.

[0007] In the first embodiment, a first load-bearing surface, in which the inner periphery of the conical spring abuts against each other, is formed on the sleeve, and a second load-bearing surface, in which the outer periphery abuts against each other, is formed on the baffle.

[0008] Both the first load support surface and the second load support surface have stepped portions that recede axially when the conical spring is assembled in opposite directions, in order to accommodate the outer and inner peripheries of the conical spring.

[0009] The radial position of the boundary of the stepped portion of the first load support surface is on the outer periphery compared to the radial position of the boundary of the stepped portion of the second load support surface.

[0010] In the second embodiment, a first load-bearing surface, in which the inner periphery of the conical spring abuts against each other, is formed on the sleeve, and a second load-bearing surface, in which the outer periphery abuts against each other, is formed on the baffle.

[0011] On the aforementioned first load support surface, a stepped portion is formed that retracts axially to accommodate the outer periphery of the conical spring when it is assembled in the opposite direction.

[0012] The radial position of the boundary of the stepped portion of the first load support surface is on the outer periphery compared to the radial position of the inner peripheral edge of the second load support surface, which is a flat surface.

[0013] In the third embodiment, a first load-bearing surface, in which the outer periphery of the conical spring abuts against each other, is formed on the sleeve, and a second load-bearing surface, in which the inner periphery abuts against each other, is formed on the baffle.

[0014] Both the first load support surface and the second load support surface have stepped portions that recede axially when the conical spring is assembled in opposite directions, in a manner that accommodates the inner and outer peripheries of the conical spring.

[0015] The radial position of the boundary of the stepped portion of the first load support surface is on the inner circumferential side compared to the radial position of the boundary of the stepped portion of the second load support surface.

[0016] In the fourth embodiment, a first load-bearing surface, in which the outer periphery of the conical spring abuts against each other, is formed on the sleeve, and a second load-bearing surface, in which the inner periphery abuts against each other, is formed on the baffle.

[0017] On the aforementioned first load support surface, a stepped portion is formed that retracts axially to accommodate the inner periphery of the conical spring when it is assembled in the opposite direction.

[0018] The radial position of the boundary of the stepped portion of the first load support surface is within the radial range of the second load support surface, which becomes a flat surface.

[0019] In the above structure, even if an excessive axial load is applied to the conical spring, the spring is held in a flat state by the flat portions of the first and second load support surfaces, thus preventing the generation of a force (torque) that would cause the spring to reverse its original conical orientation. Therefore, there is no concern about the spring reversing. Attached Figure Description

[0020] Figure 1 This is a cross-sectional view showing the main part of the first embodiment of the friction generating mechanism according to the present invention.

[0021] Figure 2 This is a top view of the conical spring of the first embodiment.

[0022] Figure 3 This is a cross-sectional view of the conical springs assembled in opposite directions.

[0023] Figure 4 This is a cross-sectional view showing the main part of the second embodiment of the friction generating mechanism.

[0024] Figure 5 This is an explanatory diagram of the friction generating mechanism of the second embodiment when it is subjected to an axial load.

[0025] Figure 6 This is an illustration of a proportional friction generating mechanism under axial load.

[0026] Figure 7 This is a cross-sectional view showing the main part of the third embodiment of the friction generating mechanism.

[0027] Figure 8 This is a top view of the conical spring in the third embodiment.

[0028] Figure 9 This is a cross-sectional view showing the main part of the fourth embodiment of the friction generating mechanism. Detailed Implementation

[0029] Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0030] Figure 1This illustration shows a first embodiment of the friction generating mechanism 1, a key component of the vibration damping device according to the present invention. The overall structure of the vibration damping device is a known structure as disclosed in Patent Document 1, etc., and therefore is omitted from the illustration. For example, it includes: an input-side rotating member 2, which is mounted on the flywheel of an internal combustion engine and receives torque from the engine; and an output-side rotating member 3, which is rotatably combined with the input-side rotating member 2. The output-side rotating member 3, for example, has a splined hub 4 at its rotational center that splines into contact with the input shaft of a transmission. The splined hub 4 has: a cylindrical boss portion 4a; and a disc portion 4b extending from the axial center of the boss portion 4a outwards. Furthermore, Figure 1 The left side of the image represents the internal combustion engine, and the right side represents the transmission.

[0031] The input-side rotating component 2 joins the outer periphery of a nearly circular baffle 5 located on the transmission side and a nearly circular cover plate (not shown) located on the internal combustion engine side, forming a disc shape. The disc portion 4b of the splined hub 4, which is part of the output-side rotating component 3, is sandwiched between these two plates. Between the disc portion 4b and the input-side rotating component 2, a plurality of helical springs (not shown in the figures, for example, four) are arranged along the tangential direction of rotation to elastically connect the two in the rotational direction. The elastic force of these helical springs absorbs torsional vibrations. The baffle 5 and the cover plate (not shown) are formed by stamping metal sheets. Furthermore, Figure 1 Only the inner periphery of baffle 5 is shown in the image.

[0032] The friction generating mechanism 1 generates a frictional torque that becomes a damping force due to the relative rotation of the input-side rotating component 2 and the output-side rotating component 3. It is configured to have: an annular sleeve 6 made of a hard synthetic resin such as engineering plastic; and an annular conical spring 7, which is disposed in a compressed state between the sleeve 6 and the baffle 5.

[0033] The sleeve 6 is rotatably fitted onto the outer peripheral surface of the boss portion 4a of the splined hub 4, and the annular friction surface 6a on the back side contacts the annular friction surface 4c of the disc portion 4b of the splined hub 4. The aforementioned annular friction surfaces 6a and 4c slide in contact along a plane orthogonal to the axis of rotation (hereinafter referred to as the axially orthogonal plane), generating frictional torque. The sleeve 6 has a cylindrical portion 6b extending towards the transmission side, thus forming an overall cross-section approximately L-shaped. A conical spring 7 is fitted onto the outer periphery of the cylindrical portion 6b, using this cylindrical portion 6b for radial positioning.

[0034] The inner circumferential portion of the baffle 5 is axially opposite to the sleeve 6, and the conical spring 7 is disposed between them. Furthermore, the inner circumferential end of the baffle 5 is located slightly on the outer circumferential side than the cylindrical portion 6b of the sleeve 6, and the two partially overlap axially.

[0035] The conical spring 7 has a conical cross-sectional shape that is inclined at a small angle relative to the plane orthogonal to the axis. In this first embodiment, the cross-section of the conical spring 7 is inclined in a direction such that the inner peripheral edge 7a is located relatively close to the sleeve 6 in the axial direction and the outer peripheral edge 7b is located relatively close to the baffle 5 in the axial direction. Furthermore, regarding the conical spring 7 used in the first embodiment, as... Figure 2 As shown in the top view, the inner periphery 7a is circular and continuous, while the outer periphery 7b forms multiple cuts 8, thus creating a concave-convex shape.

[0036] The sleeve 6 has a first load support surface 9 where the inner periphery 7a of the conical spring 7 abuts. The first load support surface 9 rises at a right angle from the inner periphery of the cylindrical portion 6b and is formed along an orthogonal plane. Additionally, the baffle 5 has a second load support surface 10 where the outer periphery 7b of the conical spring 7 abuts. This second load support surface 10 is also formed along an orthogonal plane. The first load support surface 9 and the second load support surface 10 are axially opposed to each other.

[0037] Furthermore, the first load support surface 9 has a stepped portion 9a that retracts axially to accommodate the outer periphery 7b of the conical spring 7 when it is incorrectly assembled in the opposite direction. The stepped portion 9a is located on the outer periphery of the sleeve 6. Normally, the conical spring 7 does not contact this stepped portion 9a. Therefore, the actual first load support surface 9 is simply the flat surface portion 9b of the inner periphery, excluding the stepped portion 9a.

[0038] Similarly, the second load support surface 10 has a stepped portion 10a that retracts axially to accommodate the inner periphery 7a of the conical spring 7 when it is incorrectly assembled in the opposite direction. The stepped portion 10a is formed by deep drawing the inner periphery of the baffle 5 made of a metal plate. Normally, the conical spring 7 does not contact the stepped portion 10a. Therefore, the actual second load support surface 10 is simply the flat surface portion 10b on the outer periphery, excluding the stepped portion 10a.

[0039] Here, the radial position of the boundary 9c of the stepped portion 9a of the first load support surface 9 is further outward than the radial position of the boundary 10c of the stepped portion 10a of the second load support surface 10. That is, as Figure 1 As shown, the diameter D1 of the boundary 9c of the first load support surface 9 is larger than the diameter D2 of the boundary 10c of the second load support surface 10. Therefore, when the first load support surface 9 and the second load support surface 10 are viewed by axial projection, the flat surface portion 9b of the inner periphery of the first load support surface 9, which is substantial, and the flat surface portion 10b of the outer periphery of the second load support surface 10, which is substantial, overlap each other with a certain degree of radial width.

[0040] Regarding the friction generating mechanism 1 of the vibration damping device configured in this way, the conical spring 7, which is supported on the baffle 5 by the outer periphery 7b, pre-tightens the sleeve 6 toward the disc 4b in the axial direction, thereby achieving a state in which the annular friction surfaces 6a and 4c are properly pressed together.

[0041] In addition, the stepped portions 9a and 10a respectively provided on the first load support surface 9 and the second load support surface 10 help to detect misassembly of the conical spring 7 in the inspection process where the spring is incorrectly assembled in the opposite direction. Figure 3 This indicates a state where the conical spring 7 is incorrectly assembled in the opposite direction. In this state, the outer periphery 7b of the conical spring 7, which is oriented in the opposite direction to its correct orientation, enters the stepped portion 9a of the first load support surface 9, and the inner periphery 7a enters the stepped portion 10a of the second load support surface 10. Therefore, in order to... Figure 1 The comparison makes it easy to understand that the axial preload of the conical spring 7 is significantly reduced. Therefore, if the friction torque of the friction generating mechanism 1 is checked after assembling the vibration damping device, misassembly can be easily detected.

[0042] Furthermore, the conical spring 7 is assembled in a standard orientation. Figure 1 In this configuration, the uneven outer periphery 7b abuts against the metal baffle 5, while the smooth, continuous inner periphery 7a abuts against the synthetic resin sleeve 6. Conversely, in the incorrectly assembled state facing the opposite direction... Figure 3 Under these conditions, the uneven outer periphery 7b abuts against the synthetic resin sleeve 6, which cannot ensure durability. Therefore, misassembly can be eliminated by inspection after assembly. Assuming that the conical spring 7 facing opposite directions is assembled between the first load support surface 9 and the second load support surface 10, which are formed as parallel surfaces without stepped portions 9a and 10a, the standard orientation and preload are almost unchanged, so it is difficult to detect misassembly caused by frictional torque characteristics.

[0043] On the other hand, the formation of the aforementioned stepped portions 9a and 10a could potentially cause the conical spring 7 to reverse in the opposite direction to its original conical orientation when an excessive load is applied axially. However, in the structure of the first embodiment described above, as mentioned above, the relationship is formed as "D1 > D2", so that even if an excessive load is applied axially, the conical spring 7 will not reverse. That is, the conical spring 7 is merely clamped between two load-bearing surfaces 9 and 10 (flat surfaces 9b and 10b) that are parallel to each other and orthogonal to the axis between diameters D1 and D2, and no torque is generated that would cause the conical spring 7 to reverse. Furthermore, this effect will be further explained in the latter half using the second embodiment.

[0044] Figure 4This describes a second embodiment of the friction generating mechanism 1. Furthermore, descriptions repeating those of the first embodiment will be omitted below. In this second embodiment, similar to the first embodiment, a stepped portion 9a is formed on the first load support surface 9 of the sleeve 6 to accommodate the outer peripheral edge 7b of the conical spring 7 when it is incorrectly assembled in the opposite direction. On the other hand, the stepped portion 10a is not formed on the second load support surface 10 on the side of the baffle 5, as in the first embodiment. That is, the second load support surface 10 is flat up to the inner peripheral end edge 10d opposite to the inner peripheral edge 7a of the conical spring 7.

[0045] Here, the radial position of the boundary 9c of the stepped portion 9a of the first load support surface 9 is further outward than the radial position of the inner peripheral edge 10d of the second load support surface 10. That is, the diameter D3 of the boundary 9c of the first load support surface 9 is greater than the diameter D4 of the inner peripheral edge 10d of the second load support surface 10. Therefore, when the first load support surface 9 and the second load support surface 10 are viewed by axial projection, the flat surface portion 9b of the inner peripheral side of the first load support surface 9, which is substantial, overlaps with the flat second load support surface 10 to some extent in terms of radial width.

[0046] In a structure that has a stepped portion 9a only on the first load support surface 9, when the conical spring 7 is incorrectly assembled in the opposite direction, the outer periphery 7b of the conical spring 7 also enters the stepped portion 9a, thereby significantly reducing the axial preload of the conical spring 7, thus enabling inspection during the inspection process.

[0047] Furthermore, by forming a relationship of "D3 > D4", similar to the first embodiment, it is possible to avoid the reversal of the conical spring 7 when an excessive load is applied to the axial direction.

[0048] Figure 5 This is an explanatory diagram illustrating the principle of preventing the conical spring 7 from reversing relative to axial load. Here, the second embodiment will be used as an example. Figure (b) shows the neutral state without axial load. Furthermore, the conical spring 7 is in its initial assembled state under compression, therefore, in this example, displacement occurs until it reaches a near-flat state. Figure (a) shows the state in which the splined hub 4, which is the output-side rotating member 3, is subjected to axial load relative to the baffle 5, which is the input-side rotating member 2, as indicated by the arrow, facing to the left in the figure. An axial load in this direction will not specifically cause the conical spring 7 to reverse.

[0049] Figure (c) shows the splined hub 4, which is the output-side rotating component 3, under axial load as indicated by the arrow, facing to the right in the figure. At this time, the inner periphery 7a of the conical spring 7 is pressed to the right in the figure, and the outer periphery 7b of the conical spring 7 is pressed to the left in the figure. However, since the relationship is formed as "D3 > D4", the conical spring 7 is clamped by the overlapping, flat first load support surface 9 (flat surface portion 9b) and second load support surface 10, respectively, without generating a torque that would cause the conical spring 7 to reverse.

[0050] Figure 6 This is an explanatory diagram illustrating the reversal of the conical spring 7 in the comparative example. This comparative example is, for example, equivalent to... Figure 1 In the first embodiment, the diameters D1 and D2 are reversed, with "D1 < D2". That is, the boundary 9c of the stepped portion 9a of the first load support surface 9 is located on a position closer to the inner circumference than the boundary 10c of the stepped portion 10a of the second load support surface 10. Figure (b) shows the neutral state without axial load, and Figure (a) shows the state in which the splined hub 4, as the output-side rotating member 3, is subjected to axial load relative to the baffle 5, as the input-side rotating member 2, to the left in the figure, as indicated by the arrow.

[0051] Figure (c) shows the splined hub 4, which is the output-side rotating component 3, under an axial load to the right as indicated by the arrow. If a large axial load is applied in the direction shown in Figure (c), the inner periphery 7a of the conical spring 7 is pressed to the right in the figure, and the outer periphery 7b of the conical spring 7 is pressed to the left in the figure. At this time, the point of application of the force pressing the conical spring 7 to the right in the figure is located on the inner periphery side compared to the point of application of the force pressing to the left in the figure. Therefore, sometimes the conical spring 7 is subjected to a cone-shaped torque in the opposite direction, causing it to reverse as shown in the figure, even when it is in a flat state. Moreover, cracks often occur during this reversal.

[0052] Next, based on Figure 7 A third embodiment of the friction generating mechanism 1 will be described. In this third embodiment, the conical spring 7 has a conical cross-section that is inclined in the opposite direction to the conical springs 7 of the first and second embodiments. Furthermore, as... Figure 8 As shown, the conical spring 7 used in the third embodiment is formed in a concave-convex shape by having a continuous outer periphery 7b and multiple cutouts 8 formed on the inner periphery 7a.

[0053] The sleeve 6 has a first load support surface 9 where the outer periphery 7b of the conical spring 7 abuts. The baffle 5 has a second load support surface 10 where the inner periphery 7a of the conical spring 7 abuts. The first load support surface 9 and the second load support surface 10 are still formed along an orthogonal plane and are axially opposite to each other.

[0054] Furthermore, on the first load support surface 9, a stepped portion 9a is formed on the inner circumferential side that retracts axially to accommodate the inner periphery 7a of the conical spring 7 when the conical spring 7 is incorrectly assembled in the opposite direction. Normally, the conical spring 7 does not contact this stepped portion 9a. Therefore, the actual first load support surface 9 is simply the flat surface portion 9b on the outer circumferential side, excluding the stepped portion 9a.

[0055] Similarly, on the outer peripheral side of the second load support surface 10, a stepped portion 10a is formed that retracts axially in such a way as to accommodate the outer peripheral edge 7b of the conical spring 7 when it is incorrectly assembled in the opposite direction. Normally, the conical spring 7 does not contact this stepped portion 10a. Therefore, the actual second load support surface 10 is only the flat surface portion 10b on the inner peripheral side, excluding the stepped portion 10a.

[0056] Here, the radial position of the boundary 9c of the stepped portion 9a of the first load support surface 9 is on the inner circumferential side compared to the radial position of the boundary 10c of the stepped portion 10a of the second load support surface 10. That is, as... Figure 7 As shown, the diameter D5 of the boundary 9c of the first load support surface 9 is smaller than the diameter D6 of the boundary 10c of the second load support surface 10. Therefore, when the first load support surface 9 and the second load support surface 10 are viewed by axial projection, the flat surface portion 9b of the outer periphery of the first load support surface 9, which is substantial, and the flat surface portion 10b of the inner periphery of the second load support surface 10, which is substantial, overlap each other with a certain degree of radial width.

[0057] Therefore, in this embodiment, assuming that the conical spring 7 is incorrectly assembled in the opposite direction, the inner periphery 7a of the conical spring 7 also enters the stepped portion 9a, and the outer periphery 7b enters the stepped portion 10a, thus significantly reducing the preload of the conical spring 7. Therefore, the abnormality can be detected during the inspection process.

[0058] Furthermore, when an excessive axial load is applied, the points of application of the two forces form a relationship of "D5 < D6", thus no torque is generated that would cause the cone to reverse its orientation. Therefore, similar to the first and second embodiments, there is no concern about the cone spring 7 reversing.

[0059] Furthermore, in this third embodiment, the conical spring 7 has an inner periphery 7a with a concave-convex shape that abuts against the metal baffle 5.

[0060] Next, Figure 9This describes a fourth embodiment of the friction generating mechanism 1. In this fourth embodiment, similar to the third embodiment, a stepped portion 9a is formed on the inner circumferential side of the first load support surface 9 of the sleeve 6 to accommodate the inner peripheral edge 7a of the conical spring 7 when it is incorrectly assembled in the opposite direction. On the other hand, the stepped portion 10a is not formed on the second load support surface 10 on the side of the baffle 5, as in the third embodiment. That is, the entire portion of the second load support surface 10 from its inner circumferential end edge 10d to the portion opposite to the outer peripheral edge 7b of the conical spring 7 is a flat surface.

[0061] Here, the radial position of the boundary 9c of the stepped portion 9a of the first load support surface 9 is within the radial range of the second load support surface 10, which is a flat surface. That is, when the first load support surface 9 and the second load support surface 10 are projected axially, the flat portion 9b of the outer periphery of the first load support surface 9, which is substantial, overlaps with the flat second load support surface 10.

[0062] In a structure that has a stepped portion 9a only on the first load support surface 9, when the conical spring 7 is incorrectly assembled in the opposite direction, the inner periphery 7a of the conical spring 7 also enters the stepped portion 9a, thereby significantly reducing the axial preload of the conical spring 7, thus enabling inspection during the inspection process.

[0063] In addition, the flat surface portion 9b on the outer periphery of the first load support surface 9 is located in a radial position that overlaps with the flat second load support surface 10, thereby preventing the conical spring 7 from reversing when an excessive load is applied axially, similar to the third embodiment.

Claims

1. A vibration damping device, comprising: First rotating component; The second rotating component is configured to rotate relative to the first rotating component. A spring component for elastically connecting the first rotating component and the second rotating component in the rotational direction; and A friction generating mechanism generates frictional torque in response to the relative rotation of the first rotating component and the second rotating component, wherein, The above-mentioned friction generating mechanism has: The sleeve is formed such that its back side contacts the annular friction surface of the second rotating component mentioned above, and its cross-section is approximately L-shaped; A baffle, which is part of the first rotating component that is axially opposite to the sleeve; and A ring-shaped conical spring, in a compressed state, is positioned between the sleeve and the baffle to preload the sleeve toward the ring-shaped friction surface. A first load-bearing surface, in which the inner periphery of the aforementioned conical spring abuts against each other, is formed on the aforementioned sleeve, and a second load-bearing surface, in which the outer periphery abuts against each other, is formed on the aforementioned baffle. On the first load support surface and the second load support surface, respectively, there are first and second stepped portions that are axially retracted when the conical spring is assembled in opposite directions, in order to accommodate the outer and inner peripheries of the conical spring. The radial position of the boundary of the first step portion of the first load support surface is on the outer periphery compared to the radial position of the boundary of the second step portion of the second load support surface.

2. The vibration damping device according to claim 1, wherein, The inner periphery of the aforementioned conical spring is circular and continuous, while the outer periphery is formed into an uneven shape due to multiple cuts.

3. The vibration damping device according to claim 1, wherein, The sleeve is made of synthetic resin, and the baffle is made of metal.

4. The vibration damping device according to claim 1, wherein, The conical spring described above has a continuous circular portion that contacts the sleeve described above.

5. The vibration damping device according to claim 1, wherein, The conical spring described above has a concave-convex portion that contacts the baffle.

6. The vibration damping device according to claim 1, wherein, The first diameter of the boundary of the first step is greater than the second diameter of the boundary of the second step.

7. The vibration damping device according to claim 6, wherein, The aforementioned conical spring is clamped in the region between the aforementioned first diameter and the aforementioned second diameter.

8. The vibration damping device according to claim 1, wherein, The first load support surface is parallel to the second load support surface.

9. The vibration damping device according to claim 8, wherein, The first load support surface and the second load support surface are perpendicular to the axial direction.

Images