Optimized mass cast rod pin for bushing assembly

Abstract

A bushing assembly is provided. The bushing assembly includes an inner sleeve, an outer sleeve, an elastomer, and a rod pin. The elastomer is disposed between the inner sleeve and the outer sleeve. The rod pin includes a first end, a second end, and a central portion between the first end and the second end. The central portion extends along a longitudinal axis. The central portion has a cross-shaped cross-section perpendicular to the longitudinal axis. The rod pin further includes a first intermediate portion between the central portion and the first end. The first intermediate portion has an uninterrupted circular cross-section perpendicular to the longitudinal axis. The inner sleeve circumscribes the central portion of the rod pin.

Description

Technical Field

[0001] This disclosure relates to optimized quality cast rod pins and bushing assemblies including optimized quality cast rod pins. Background Technology

[0002] This section provides background information relating to this disclosure, which is not necessarily prior art.

[0003] Applications of elastomeric bushing assemblies include, but are not limited to, torsion bars, linear torsion bars, V-torsion bars, leaf springs, independent suspension control arms, and other suspension control devices. These and other applications are used in a variety of vehicles, such as automobiles, trucks, buses, off-highway vehicles, rail vehicles, and other transportation applications.

[0004] An elastomeric bushing assembly typically includes an outer metal, an inner metal, and an elastomeric bushing disposed between the outer metal and the inner metal. The outer metal may be a tubular member that is part of a component that incorporates the elastomeric bushing assembly, or the outer metal may be a separate tubular member designed to be assembled to or otherwise attached to a component that incorporates the elastomeric bushing assembly by pressure fitting.

[0005] The internal metal is typically a solid tubular component suitable for attachment to vehicle and / or suspension components in applications including the use of an elastomeric bushing assembly. An example of internal metal is a rod pin having a cylindrical central segment and end segments located at both ends of the central segment. The end segments extend from the central segment and may include orifices, grooves, or other features for securing the elastomeric bushing assembly to the vehicle and / or suspension component in the application. Summary of the Invention

[0006] This section provides the general inventive summary of this disclosure, but is not a complete disclosure of its full scope or all its features.

[0007] This disclosure provides a bushing assembly. The bushing assembly includes an inner sleeve, an outer sleeve, an elastomer, and a pin. The elastomer is disposed between the inner sleeve and the outer sleeve. The pin includes a first end, a second end, and a central portion between the first and second ends. The central portion extends along a longitudinal axis. The central portion has a cross-shaped cross-section perpendicular to the longitudinal axis. The pin also includes a first intermediate portion located between the central portion and the first end. The first intermediate portion has a continuous circular cross-section perpendicular to the longitudinal axis. The central portion of the pin is connected to the inner sleeve.

[0008] In some configurations, the pin also includes a second intermediate portion located between the central portion and the second end. This second intermediate portion has a continuous circular cross-section perpendicular to the longitudinal axis.

[0009] In some configurations, the first diameter of the central portion is the same as the second diameter of the first intermediate portion.

[0010] In some configurations, the inner sleeve includes an inner surface that directly engages with the central portion of the rod pin.

[0011] In some configurations, the pin is pressure-fitted into the inner sleeve.

[0012] In some configurations, the perimeter of the central portion is defined by a discontinuous circle.

[0013] In some configurations, the cruciform cross-section defines the diameter. The first area of ​​the cruciform cross-section ranges from 25% to 50% of the second area of ​​the circle having the diameter.

[0014] The first area is 30% to 40% of the second area.

[0015] In some configurations, the pins are made of ductile iron.

[0016] In some configurations, the pin also includes a radially extending flange located between the second intermediate portion and the second end.

[0017] In some configurations, the radially extending flange includes a first side adjacent to the first intermediate portion. This first side is perpendicular to the longitudinal axis.

[0018] In some configurations, the periphery of the radially extending flange defines multiple recesses.

[0019] In some configurations, the pin also includes a first flat portion and a second flat portion. The first flat portion is located between a first end and a first intermediate portion. The second flat portion is located between a second end and a center portion.

[0020] In some configurations, the pin includes a pair of rounded corners located between the first flat portion and the first intermediate portion.

[0021] In some configurations, a first flat portion defines a first orifice, and a second flat portion defines a second orifice.

[0022] In some configurations, the first flat portion and the second flat portion are coplanar.

[0023] In some configurations, the bushing assembly also includes an intermediate sleeve. This intermediate sleeve is located between the inner sleeve and the outer sleeve. The elastomer includes a first elastomer and a second elastomer. The first elastomer is located between the outer sleeve and the intermediate sleeve. The second elastomer is located between the inner sleeve and the intermediate sleeve.

[0024] This disclosure provides a method for manufacturing a bushing assembly. The method includes casting a rod pin. The rod pin includes a first end, a second end, and a central portion between the first and second ends. The central portion extends along a longitudinal axis. The central portion has a cross-shaped cross-section perpendicular to the longitudinal axis. The rod pin also includes a first intermediate portion located between the central portion and the first end. The first intermediate portion has a continuous circular cross-section perpendicular to the longitudinal axis. The method further includes pressure fitting the rod pin into a bushing. The bushing includes an inner sleeve, an outer sleeve, and an elastomer disposed between the inner sleeve and the outer sleeve. The central portion of the rod pin is externally connected to the inner sleeve.

[0025] In some configurations, the method also includes a machining center component.

[0026] In some configurations, the cast rod pins include rod pins cast from ductile iron. Attached Figure Description

[0027] The accompanying drawings described herein are for illustrative purposes only for the selected embodiments and not for all possible specific implementations, and are not intended to limit the scope of this disclosure.

[0028] Figure 1 This is a perspective view of a lever pin based on the principles of this disclosure;

[0029] Figure 2 yes Figure 1 Another perspective view of the lever pin shown;

[0030] Figure 3 Therefore Figure 1 The line 3-3 was cut Figure 1 A cross-sectional view of the rod pin shown;

[0031] Figure 4 Therefore Figure 1 The line 4-4 was cut Figure 1 A cross-sectional view of the rod pin shown;

[0032] Figure 5 This is a perspective view of a bushing assembly based on the principles of this disclosure, the bushing assembly including... Figure 1 The lever pin shown;

[0033] Figure 6 Therefore Figure 5 The line 6-6 was cut Figure 5 A cross-sectional view of the bushing assembly shown; and

[0034] Figure 7 This illustrates the manufacture according to the principles of this disclosure. Figure 5 The flowchart shows the method for the bushing assembly.

[0035] In several views throughout the accompanying drawings, the corresponding reference numerals indicate the corresponding parts. Detailed Implementation

[0036] Exemplary embodiments will now be described more fully with reference to the accompanying drawings.

[0037] Exemplary embodiments are provided so that this disclosure will be thorough and will fully convey the scope to those skilled in the art. Numerous specific details, such as examples of specific components, apparatuses, and methods, are set forth to provide a thorough understanding of embodiments of this disclosure. It will be apparent to those skilled in the art that specific details are not required, that these exemplary embodiments may be embodied in many different forms, and should not be construed as limiting the scope of this disclosure. In some exemplary embodiments, well-known processes, well-known apparatus structures, and well-known techniques are not described in detail.

[0038] The terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” may also be intended to include the plural forms unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having” are inclusive and thus specify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. Unless there is an explicit order of execution, the method steps, processes, and operations described herein should not be construed as requiring performance in the specific order discussed or described. It should also be understood that additional or alternative steps may be employed.

[0039] When an element or layer is referred to as “on,” “joined to,” “connected to,” or “attached to” another element or layer, the element or layer may be directly on, joined to, connected to, or attached to the other element or layer, or there may be intermediate elements or layers present. Conversely, when an element is referred to as “directly on,” “directly joined to,” “directly connected to,” or “directly attached to” another element or layer, there may be no intermediate elements or layers present. Other terms used to describe relationships between elements should be interpreted in a similar manner (e.g., “between” vs. “directly between,” “adjacent” vs. “directly adjacent,” etc.). As used herein, the term “and / or” includes any and all combinations of one or more of the listed items.

[0040] Although the terms first, second, third, etc., may be used herein to describe various elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or segment from another. Unless the context clearly indicates otherwise, terms such as “first,” “second,” and other numerical terms used herein do not imply sequence or order. Therefore, without departing from the teachings of the exemplary embodiments, the first element, component, region, layer, or segment described below may be referred to as a second element, component, region, layer, or segment.

[0041] Spatially related terms such as “inner,” “outer,” “below,” “below,” “lower,” “above,” and “upper” are used herein to describe the relationship of one element or feature to another, as shown in the figures. In addition to the orientations shown in the figures, spatially related terms may also be intended to cover different orientations of the device during use or operation. For example, if the device in the figures is flipped, then an element described as “below” or “below” other elements or features would be oriented as “above” other elements or features. Thus, the exemplary term “below” can cover both above and below orientations. The device can be oriented in other ways (rotated 90 degrees or otherwise), and the spatially related descriptors used herein are interpreted accordingly.

[0042] refer to Figures 1 to 2 A lever pin 10 is provided in accordance with the teachings herein. This lever pin 10 can be adapted for use with a bushing to form a bushing assembly, as will be described below (see Appendix). Figure 5 To be continued Figure 6 (Discussion). The pin 10 can have a one-piece integral structure. In some embodiments, the pin 10 can be constructed of ductile iron.

[0043] The pin 10 extends along the longitudinal axis 20 between a first end 22 and a second end 24. The pin 10 includes a central portion 26 located between the first end 22 and the second end 24. This central portion 26 includes a cross-shaped cross section perpendicular to the longitudinal axis 20, as will be described in more detail below (see Appendix). Figure 4 (Discussion). In some embodiments, the central portion 26 has a constant diameter along the longitudinal axis 20, as shown in the figure.

[0044] The rod pin 10 also includes a first intermediate portion 30 and a second intermediate portion 32. The first intermediate portion 30 is disposed between the first end 22 and the center portion 26. The second intermediate portion 32 is disposed between the second end 24 and the center portion 26. Each of the first intermediate portion 30 and the second intermediate portion 32 defines a continuous circular cross-section parallel to the longitudinal axis 12.

[0045] The pin 10 also includes a first flat portion 40 and a second flat portion 42. The first flat portion 40 is disposed between the first end 22 and the first intermediate portion 30. The second flat portion 42 is disposed between the second end 24 and the second intermediate portion 32. Each of the first flat portion 40 and the second flat portion 42 has a rectangular cross-section perpendicular to the longitudinal axis 12. As used herein, a “flat portion” refers to a region having opposing planar parallel surfaces 44. In some embodiments, the first flat portion 40 and the second flat portion 42 may be coplanar, such that they are positioned at a common angular location about the longitudinal axis, and the surfaces 44 are parallel to each other, as shown in the figure.

[0046] In some embodiments, a first flat portion 40 defines a first aperture 50, and a second flat portion 42 defines a second aperture 52, as shown. The first aperture 50 and the second aperture 52 can be used to secure the rod pin 10 (together with the bushing) to the vehicle. In other embodiments, the rod pin may include different or additional features for securing the rod pin to the vehicle, such as a cylindrical end portion defining a corresponding annular groove.

[0047] The pin 10 may also include a fillet 60. A pair of fillets 60 can connect each of the first intermediate portion 60 and the second intermediate portion 62 to a corresponding pair of surfaces 44 of the first flat portion 40 and the second flat portion 42.

[0048] The pin 10 may also include a radially extending flange 70 (also referred to as "flange 70"). The flange 70 may extend radially beyond the center portion 26 and the first intermediate portion 30 and the second intermediate portion 32. In some embodiments, the flange 70 may be disposed between the second intermediate portion 32 and the second flat portion 42, as shown. In other embodiments, the flange may alternatively be disposed between the first intermediate portion and the second flat portion.

[0049] The periphery 72 of the flange may define a plurality of recesses 74. Each recess 74 may define an arcuate or partially circular shape. In some embodiments, the plurality of recesses 74 may include four recesses, as shown in the figure. The recesses 74 may be equidistantly spaced around the periphery 72.

[0050] refer to Figure 3 The flange 70 may include a first flange surface 80 and a second flange surface 82. At least a portion of the first flange surface 80 may be planar and extend perpendicular to the longitudinal axis 20. At least a portion of the second surface 82 may form an angle relative to the longitudinal axis 20. The first intermediate portion 30 and the second intermediate portion 20 may each extend perpendicular to the longitudinal axis 20.

[0051] refer to Figure 4 As described above, the central portion 26 is defined parallel to the longitudinal axis 20. Figure 3 The central portion 26 has a cross-shaped cross-section. Compared to a rod pin with a cylindrical central portion, the cross-shaped cross-section reduces the mass of the central portion 26 while maintaining its structural integrity. The central portion 26 may include four spokes 100 extending radially outward from the central hub 101. Each spoke 100 may be spaced 90° apart from adjacent spokes 100. Each spoke 100 may be connected to adjacent spokes 100 by a longitudinal fillet 102. The central portion 26 may be connected to corresponding first intermediate portions 30 and second intermediate portions 32 by a transverse fillet 104.

[0052] The periphery 110 of the center portion 26 may define a discontinuous circle. Therefore, the outer surface 112 of each spoke in the spokes 100 may be rounded. The center portion 26 defines a first diameter 120. A first intermediate portion 30 and a second intermediate portion 32 define a second diameter 122. The first diameter 120 and the second diameter 122 may be identical.

[0053] The central portion 26 is perpendicular to the longitudinal axis 20 ( Figure 3 The area can be greater than about 20% of the area of ​​the circle having a first diameter of 120, optionally greater than about 25%, optionally greater than about 30%, optionally greater than about 35%, optionally greater than about 40%, optionally greater than about 45%, optionally greater than about 50%, optionally greater than about 55%, optionally greater than about 60%, or optionally greater than about 65%. The area can be less than or equal to about 70% of the area of ​​the circle having a first diameter of 120, optionally less than or equal to about 65%, optionally less than or equal to about 60%, optionally less than or equal to about 55%, optionally less than or equal to about 50%, optionally less than or equal to about 45%, optionally less than or equal to about 40%, optionally less than or equal to about 35%, optionally less than or equal to about 25%, or optionally less than or equal to about 20%. For example, the range of the area can be from 25% to 50% of the area of ​​the circle having a first diameter of 120, or optionally from 30% to 40%.

[0054] Compared to a rod pin with a cylindrical central portion, rod pin 10 has a reduced weight. For example, the weight reduction compared to a rod pin with a cylindrical central portion can be greater than or equal to about 10%, optionally greater than or equal to about 15%, optionally greater than or equal to about 20%, optionally greater than or equal to about 25%, optionally greater than or equal to about 30%, optionally greater than or equal to about 35%, optionally greater than or equal to about 40%, or optionally greater than or equal to about 45%. Compared to a rod pin with a circular central portion, the weight reduction can be less than or equal to about 50%, optionally less than or equal to about 45%, optionally less than or equal to about 40%, optionally less than or equal to about 35%, optionally less than or equal to about 30%, optionally less than or equal to about 25%, optionally less than or equal to about 20%, or optionally less than or equal to about 15%.

[0055] refer to Figure 5 A bushing assembly 200 is provided according to the principles of this disclosure. The bushing assembly 200 includes a rod pin 10 and a bushing 202. The rod pin 10 is press-fitted into the bushing 202.

[0056] refer to Figure 6 The bushing 202 includes an outer sleeve or tube 210 and an inner sleeve or tube 212. By way of example, the outer sleeve 210 and the inner sleeve 212 may be made of a metal such as steel. In some embodiments, the bushing 202 also includes an intermediate sleeve or tube 214, as shown. However, in other embodiments, the intermediate sleeve 214 is omitted. The bushing 202 also includes a first elastic body 216 disposed between the outer sleeve 210 and the intermediate sleeve 214 and a second elastic body 218 disposed between the inner sleeve 212 and the intermediate sleeve 214. In embodiments where the intermediate sleeve 214 is omitted, a single elastic body may be disposed directly between the outer sleeve 210 and the inner sleeve 212.

[0057] The inner sleeve 212 defines the internal region where the rod pin 10 is disposed. The inner sleeve 212 externally connects to the center portion 26 of the rod pin 10. The inner surface 222 of the inner sleeve 212 directly engages with the outer surface 112 of the center portion 26 of the rod pin 10. The flange 70 is adapted to act as a travel limiter, which sets the maximum amount of travel along the longitudinal axis 20 that can occur between the outer sleeve 210 and the rod pin 10.

[0058] refer to Figure 7 This provides a method for manufacturing and assembling bushing assembly 200 according to the teachings herein. The method typically includes: casting rod pin 10 at 250°. Figure 5 ); Machining pin 10 at position 254; and press-fitting pin 10 to bushing 202 at position 258. Figure 5At 250, the pin 10 can be cast as a single-piece integral structure, including a cross-shaped cross-section. In some embodiments, the pin 10 can be cast from ductile iron. In other embodiments, the pin 10 can be formed by other methods, such as forming from blank material and then machining. At 254, the pin 10 can undergo minor machining operations to facilitate a dimensionally precise pressure fit between the pin 10 and the bushing 202 at 258.

[0059] The foregoing description of embodiments has been provided for illustrative and descriptive purposes. It is not intended to be exhaustive or limiting of this disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but where applicable, such individual elements or features are interchangeable and can be used in selected embodiments, even if not specifically shown or described. Variations are also possible in various ways. Such variations should not be considered as departing from this disclosure, and all such modifications are intended to be included within the scope of this disclosure.

Claims

1. A bushing assembly comprising: an inner sleeve; an outer sleeve; an elastomer disposed between the inner sleeve and the outer sleeve and comprising a bumper; and a rod pin comprising a first end, a second end, and a central portion between the first end and the second end, the central portion extending along a longitudinal axis and having a cruciform cross-section perpendicular to the longitudinal axis, the rod pin further comprising a first intermediate portion between the central portion and the first end, the first intermediate portion having an uninterrupted circular cross-section perpendicular to the longitudinal axis, wherein the inner sleeve circumscribes the central portion of the rod pin; the rod pin further comprising a radially extending flange, wherein the flange is proximate to and longitudinally spaced from the bumper; wherein the rod pin further comprises a second intermediate portion between the central portion and the second end, the second intermediate portion having an uninterrupted circular cross-section perpendicular to the longitudinal axis; wherein a first diameter of the central portion at a longitudinal midpoint of the rod pin is the same as a second diameter of the first intermediate portion; wherein the rod pin further comprises a first flat portion between the first end and the first intermediate portion and a second flat portion between the second end and the central portion.

2. The bushing assembly of claim 1, wherein the inner sleeve comprises an inner surface directly engaged with the central portion of the rod pin.

3. The bushing assembly of claim 1, wherein the rod pin is press-fit into the inner sleeve.

4. The bushing assembly of claim 1, wherein a perimeter of the central portion defines an interrupted circle.

5. The bushing assembly of claim 1, wherein the cruciform cross-section defines a diameter, and a first area of the cruciform cross-section ranges from 25% to 50% of a second area of a circle having the diameter.

6. The bushing assembly of claim 5, wherein the first area ranges from 30% to 40% of the second area.

7. The bushing assembly of claim 1, wherein the rod pin further comprises a radially extending flange between the second intermediate portion and the second end.

8. The bushing assembly of claim 7, wherein the radially extending flange comprises a first side adjacent to the second intermediate portion, the first side being perpendicular to the longitudinal axis.

9. The bushing assembly of claim 7, wherein a perimeter of the radially extending flange defines a plurality of indentations.

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