EP2067736A2

EP2067736A2 - Energy absorbing lift bracket

Info

Publication number: EP2067736A2
Application number: EP08016999A
Authority: EP
Inventors: Timothy Yoon; Andrew B. Witkowski; Martin R. Zielke; Steven C. Bielaga; Tyler R. Vincer; Thomas G. Grotto
Original assignee: International Engine Intellectual Property Co LLC
Current assignee: International Engine Intellectual Property Co LLC
Priority date: 2007-10-16
Filing date: 2008-09-26
Publication date: 2009-06-10
Anticipated expiration: 2028-09-26
Also published as: CA2639792A1; BRPI0804360A2; EP2067736A3; MX2008012681A; US20090095860A1; EP2067736B1

Abstract

A lift bracket (300) includes a topmost portion (304) having an opening (302) arranged for engagement with an engagement portion of a lifting apparatus. The topmost portion (304) is substantially flat and defines a first plane (A-A). A base portion (320) of the lift bracket (300) has at least one fastener opening (322) for fastening the base portion to the engine. The base portion (320) also lies in the first plane (A-A). A yield structure (305) is disposed between the topmost portion (304) and the base portion (320), and includes a mid-portion (312) that defines at least one second plane (B-B) that is spaced and parallel to the first plane (A-A). When a tensile force is applied to the topmost portion (304), the yielding structure (305) yields, the topmost portion displaces away from the base portion (320), and the second plane (B-B) displaces towards the first plane (A-A).

Description

FIELD OF THE INVENTION

This invention relates to components for internal combustion engines. More specifically, this invention is related to components used to connect an engine with a hoist for lifting of the engine.

BACKGROUND OF THE INVENTION

Internal combustion engine handling, both during engine and vehicle assembly operations and during service, is typically accomplished by use of a hoist or crane for lifting and moving the engine. Engines typically have lift brackets, which are components that are attached to the engine that have "eye" openings. A hook that is connected to a hoist engages the eye opening. The eye openings are typically disposed toward the top of an engine to facilitate connection of the hoist thereto for lifting of the engine.
Typically, the hoist has chains connected to a lifting apparatus. On the distal end of the chain, there are typically hooks or other appropriate devices that engage the eye openings of the lift bracket on the engine. Two lifting brackets are usually used for a single engine so that the engine remains in a balanced and upright position during the lift.
Some manufacturers of engines and/or vehicles have standards requiring that a single lifting bracket be capable of supporting the weight of a given engine in the event that one of the two lifting brackets fail or the hook becomes disengaged. Due to space constraints inside the vehicle proximate the engine, there is inadequate room to enlarge the lifting bracket to the extent necessary to support the entire weight of the engine. Moreover, the lifting bracket do not perform a function once the engine is located in the vehicle, so it is not desirable to increase the weight or cost of the vehicle by significantly increasing the size of the lifting bracket. Therefore, it is desirable to have lifting brackets that are lightweight, low cost, and of simple design, but that are also strong enough to support the entire weight being lifted, which can include the transmission and the engine.

SUMMARY OF THE INVENTION

A lift bracket includes a topmost portion having an opening arranged for engagement with an engagement portion of a lifting apparatus. The topmost portion is substantially flat and defines a first plane. A base portion of the lift bracket has at least one fastener opening for fastening the base portion to the engine. The base portion also lies in the first plane. A yield structure is disposed between the topmost portion and the base portion and includes a mid-portion that defines at least one second plane that is spaced and parallel to the first plane. When a tensile force is applied to the topmost portion, the yielding structure yields, the topmost portion displaces away from the base portion, and the second plane displaces towards the first plane.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is front view of an engine having two prior art lift brackets connected thereto.
FIG. 2 is a detail view of a cylinder head that engages a lift bracket.
FIG. 3 is a perspective view of a lift bracket in accordance with the invention.
FIG. 4 is a side view of the lift bracket of FIG. 3 in accordance with the invention.
FIG. 5 is an exploded view of a cylinder head and a lift bracket in accordance with the invention.
FIG. 6 is a front view of a lift bracket connected to an engine in accordance with the invention.
FIG. 7 is a perspective view of a second embodiment of lift bracket in accordance with the invention.
FIG. 8 is a perspective view of a third embodiment of lift bracket in accordance with the invention.
FIG. 9 is a perspective view of a fourth embodiment of lift bracket in accordance with the invention.
FIG. 10 is a perspective view of a fifth embodiment of lift bracket in accordance with the invention.
FIG. 11 is a perspective view of a sixth embodiment of lift bracket in accordance with the invention.
FIG. 12 is a perspective view of a seventh embodiment of lift bracket in accordance with the invention.

DESCRIPTION OF A PREFERRED EMBODIMENT

The following describes a lift bracket on an internal combustion engine. The lift bracket is configured to support the entire weight of the internal combustion engine. The embodiments described herein use a dual lift bracket configuration for a single engine, but the advantages of the embodiments described herein can be realized in any lifting application, as will become evident to one having ordinary skill in the art.
A prior art engine 100, and a detail view of cylinder head 104, are shown in FIGS. 1 and 2 respectively. The engine 100 includes a crankcase 102. The engine 100 shown is of a "V" configuration having two banks. Each bank has a cylinder head 104 connected thereto. Each cylinder head 104 has a lower valve cover 106 connected to an upper valve cover 108 disposed thereon. Other components of the engine 100 are not shown in this figure for the sake of simplicity. A lift bracket 110 is connected onto each of the cylinder heads 104. Each lift bracket 110 forms an eye opening 112, which is advantageously a round opening used to connect a hook or other device to lift the engine 100 with a hoist or crane (not shown), however any type of opening is contemplated. Each lift bracket 110 is connected to each cylinder head 104 by use of two fasteners 114. Each fastener 114 threadably engages a fastener opening 202 formed in the cylinder head 104.
As shown in FIG. 2, each fastener opening 202 has a flat portion or pad 204 surrounding the opening 202. The pads 204 lie on a single plane and provide a flat interface for connection to the lift bracket 110.
The engine 100 has a center of gravity CG that lies on an axis that is perpendicular to a line connecting the two lift eye openings 112 and intersects the line at about the midpoint thereof. When the engine 100 is lifted with a hoist (not shown) that is connected to the engine 100 through the lift openings 112, the engine 100 remains level. In the event that one of the lifting brackets 110 fails while the engine 100 is being lifted, then the engine 100 will list on one side and rotate away from the lift bracket 110 that has not failed, and the engine will tend to pull away from the lift bracket 110. In addition to the stresses that act to pull the engine 100 away from the lift bracket 110, an impulse loading immediately following the instant of separation of the hoist will cause additional stresses at the connection between the engine 100 and the connected lift bracket 110.
An improved lift bracket 300 is shown in FIG. 3, and a side view of the lift bracket is shown in FIG. 4. The lift bracket 300 has an eye opening 302 formed in a topmost portion 304. The topmost portion 304 is disposed on a distal end of the bracket 300 and is substantially flat. A base portion 320 is substantially flat and defines a plane, A-A. The topmost portion 304 is also on plane A-A. Between the topmost portion 304 and the base portion 320 is a yield structure 305. In the embodiment of FIG. 3, the yield structure includes a first radiused portion 306, a first inclined portion 308, a second radiused portion 310, a mid-portion 312, a third radiused portion 314, a second inclined portion 316, and a fourth radiused portion 318. The first radiused portion is formed adjacent to the topmost portion 304. The first radiused portion 306 is connected to the first inclined portion 308 that lies on a plane that is at an angle, α, with respect to the topmost portion 304. The second radiused portion 310 connects an end of the first inclined portion 308 with the mid-portion 312. The mid-portion 312 is also at the angle α with respect to the first inclined portion 308, and is advantageously substantially parallel with the top most portion 304. The third radiused portion 314 connects the mid-portion 310 with the second inclined portion 316. The second inclined portion 316 forms an angle, β, with the topmost portion 304. The angles α and β are advantageously supplemental angles, meaning, that the acute angle between the second inclined portion 316 and the topmost portion 304 is also equal to α. The fourth radiused portion 318 connects the second inclined portion 316 with the base portion 320. A plane, B-B, includes the mid-portion 312. The planes A-A and B-B are advantageously substantially parallel.
In the embodiment of FIG. 3 and FIG. 4, the base portion 320 has two openings 322 formed therein. A tab 324 protrudes from the base opening 320 in a substantially perpendicular fashion, and is connected to the bracket 300 at an outer edge 326 in an area adjacent to the base portion 320. A fifth radiused portion 328 connects the tab 324 with the outer edge 326.
The bracket 300 advantageously enables formation of all radiused and flat portions thereof from a single piece of sheet metal, that is, bracket 300 is advantageously integrally formed. However, other techniques may be employed for manufacturing a lift bracket in accordance with the invention.
An exploded view of a typical installation configuration for the lift bracket 300 onto a cylinder head 500 of an internal combustion engine is shown in FIG. 5. The cylinder head 500 has two threaded fastener cavities 502, at least a portion of each surrounded by a substantially flat mounting pad 504. Each mounting pad 504 lies on a common mounting plane that corresponds to the base portion 320 of the lift bracket 300 when the lift bracket 300 is mounted onto the cylinder head 500.
During assembly, a fastener 506 is inserted through a central opening 508 of an optional spacer 510, through one of the openings 322 in the lift bracket 300, and into a corresponding fastener cavity 502 in the cylinder head 500. In the embodiment shown, two fasteners 506 are used in a similar configuration. The optional spacer 510 having the central opening 508 is shown in this embodiment as a separate piece, but can advantageously be integrated with the bracket 300. The optional spacer 510 advantageously allows each fastener 506 to bend slightly when loaded and yield partially without loss of its retentive function. The optional spacer 510 can be used with any of the embodiments of the lift bracket.
While the lift bracket 300 is connected to the cylinder head 500, each of the two fasteners 506 is threadably engaged with its corresponding fastener cavity 502. Each mounting pad 504 is in contact with an area of the base portion 320 substantially continuously. Each spacer 510 contacts the base portion 320 of the bracket 300 substantially continuously around an area thereof that surrounds each of the openings 322.
Advantageously, a tab 324 protrudes from the base portion 320 of the bracket 300 and is configured to be disposed within a slot or cutout 512 that is formed in the cylinder head 500. The disposition of the tab 324 into the slot 512 ensures that at times when the lift bracket 300 may be overloaded, for example when another such bracket fails, then rotation of the cylinder head 500 with respect to the lift bracket 300 is discouraged by an interference between the tab 324 and a wall or side portion of the slot 512.
Referring now to FIG. 6, the bracket 300 is connected to the cylinder head 500 of an engine 600. A force F is applied to the eye opening 302 of the lift bracket 300 to simulate a force condition that exists when the lift bracket 300 is supporting the entire weight of the engine 600. When two lift brackets 300 are used to lift the engine 600, the engine 600 remains relatively balanced, and each lift bracket 300 experiences a force roughly equal to half of the weight of the engine 600 (or a force equal to about F/2). In the event that one lift bracket 300 must hold the engine, the lift bracket must be capable of supporting an impulse load immediately following the failure, and then sustain the entire load of the engine 600, or alternatively, sustain the force F as shown in FIG. 6. Due to the location of the center of gravity of the engine that lies away from the axis of application of the force F, a bending moment M is created that acts on the connection interface between the bracket 300 and the cylinder head 500. This moment M is countered in a static condition by an equal and opposite counter-moment M' due to the connection of the bracket 300 to the cylinder head 500. The two fasteners 506 and interference between the tab 324 and the slot 512 sufficiently create the counter-moment M'.
The impulse loading due to a failure of one of the lifting brackets 300 typically causes subsequent failures in other components. In this case, the impulse loading and the distributed loading are advantageously absorbed by the lift bracket 300.
When the lift bracket 300 is required to absorb an impulse loading, the lift bracket 300 yields to absorb the force F at the yield structure 305, which tends to pull the topmost portion 304 away from the base portion 320. This yielding advantageously occurs at the radiused portions 306, 310, 314, and 318 that connect the first and second inclined portions 308 and 316 with the topmost portion 304, the mid-portion 312, and the base portion 320. This yielding at the yield structure 305 causes the angle α to be reduced, the lift bracket 300 to elongate, and the plane B-B of the mid-portion 312 to approach the plane A-A of the topmost and base portions 304 and 320.
Alternative embodiments for various designs for lift brackets are shown in FIG. 7 through FIG. 12. Each of these alternative embodiments is described in detail below.
A perspective view of a lift bracket 700 is shown in FIG. 7. The lift bracket 700 includes a topmost portion 704 having an eye opening 702 formed therein. A base portion 720 includes two fastener openings 722. The lift bracket 700 includes a yield structure 705 disposed between the topmost portion 704 and the base portion 720. A mid-portion 712 is in the middle of the yield structure 705. The yield structure 705 is advantageously capable of absorbing loading by transforming it to strain by elongation of at least two "wave" features that are formed between any one of a plurality of peaks 714 that are formed alternatively with a plurality of valleys 716. In the embodiment shown there are three (3) peaks 714 that smoothly merge with two valleys 716 formed therebetween resulting in a wave-shape to the yield structure 705. When the bracket 700 is subjected to a tensile load, the topmost portion 704 is advantageously capable of moving away from the base portion 720 through elongation or flattening of the waves formed by the peaks 714 and valleys 716 in the yield structure 705.
A perspective view of a lift bracket 800 is shown in FIG. 8. The lift bracket 800 is substantially similar to the lift bracket 300 shown in FIG. 3, but without the tab 324. The bracket 800 has a yield structure 805 and a mid-portion 812 disposed between a topmost portion 804 and a base portion 820. The topmost portion 804 forms an eye opening 802, and the base portion 820 forms two fastener openings 822. As described above for the embodiment shown in FIG. 3, the lift bracket 800 is advantageously capable of elongating in the yield structure 805 to absorb loading imparted on the bracket 800 when the topmost portion 804 is subjected to a tensile force that acts to pull the opening 802 away from the base portion 820.
A perspective view of a lift bracket 900 is shown in FIG. 9. The lift bracket 900 is substantially similar to the lift bracket 300 shown in FIG. 3, but with structural differences in the radiused portion 328 that forms the tab 324 thereof. The bracket 900 has a yield structure 905 and a mid-portion 912 disposed between a topmost portion 904 and a base portion 920. The topmost portion 904 forms an eye opening 902, and the base portion 920 forms two fastener openings 922.
As described above for the embodiment shown in FIG. 3, the lift bracket 900 is advantageously capable of elongating in the yield structure 905 to absorb loading imparted on the bracket 900 when the topmost portion 904 is subjected to a tensile force that acts to pull the opening 902 away from the base portion 920. An radiused portion 928 forms a tab 924 which has a "hook" shape. The tab 924 at least partially surrounds an inner cavity 926 that is capable of engaging an engine component (not shown) therewithin when the bracket 900 is installed on an engine. The bracket 900 is advantageously capable of using the structural rigidity of the engine component disposed in the inner cavity 926 of the hook 924 to augment its own structural rigidity and strength of connection to the engine. Examples of components that may be used for engagement with the hook 924 include intake manifolds, exhaust manifolds, cylinder heads, among other components.
Referring now to FIG. 10, a lift bracket 1000 is substantially similar to the lift bracket 300 shown in FIG. 3, but without the tab 324. The bracket 1000 has a yield structure including a mid-portion 1012 disposed between a topmost portion 1004 and a base portion 1020. The topmost portion 1004 forms an eye opening 1002, and the base portion 1020 forms two fastener openings 1022. The base portion 1020 forms an extension portion 1024 that includes a third fastener opening 1026. The third fastener opening 1026 advantageously acts to augment retention of the bracket 1000 onto an engine when an additional fastener is placed therein to connect the extension 1024 to the engine.
As described above for the embodiment shown in FIG. 3, the lift bracket 1000 is advantageously capable of elongating in the yield structure 1012 to absorb loading imparted on the bracket 1000 when the topmost portion 1004 is subjected to a tensile force that acts to pull the opening 1002 away from the base portion 1020, and is also capable of augmented retention of the base portion 1020 to the engine by an additional fastener (not shown) connected to the engine through the third fastener opening 1026.
A bracket 1100 is shown in FIG. 11 and includes a base portion 1120 having two fastener holes 1122 formed therein, and a topmost portion 1104 having an eye opening 1102 formed therein. A yield structure 1105 includes a mid-portion 1112 that is disposed between the topmost portion 1104 and the base portion 1120. The yield structure 1105 of the bracket 1100 comprises a first link 1124 and a second link 1126. The first and second links 1124 and 1126 are spaced apart in the plane generally perpendicular to the plane of the bracket 1100. Further, the first and second links 1124 and 1126 define an opening or slit 1128. The links 1124 and 1126 meet at a first junction 1130 adjacent to the topmost portion 1104 and at a second junction 1132 adjacent to the base portion 1120.
At times when a tensile force is applied to the eye opening 1102, the bracket 1100 is advantageously capable of a controlled deformation and absorption of strain at the yield structure 1105 without failure. During application of the tensile force, the top-most portion 1102 moves away from the base portion 1120, and the bracket 1100 elongates through deformation of the first link 1124 and the second link 1126. As the bracket 1100 elongates, the links 1124 and 1126 deform and move closer to each other (in the plane generally perpendicular to the plane of the bracket 1100), rotate at least in part around the first and second junctions 1130 and 1132, and reduce the opening of the slit 1128. Thus, the bracket 1100 is advantageously capable of absorbing energy in the form of strain of the links 1124 and 1126.
A bracket 1200 is shown in FIG. 12. The bracket 1200 includes a topmost portion 1204 having an eye opening 1202 formed therein. A base portion 1220 of the bracket 1200 has two fastener openings 1222 formed therein. Each of the topmost portion 1204 and base portion 1220 are substantially flat. In this embodiment, the topmost portion 1204 does not lie on the same plane as the base portion 1220, but rather, the topmost portion 1204 lies on a plane that forms an angle, γ, with the plane on which the base portion 1220 lies. In other words, an orientation of the lift opening 1202 is at the angle γ with respect to the fastener openings 1222. The angle γ may be selected to suit particular shape requirements of the bracket 1200, and may advantageously be about 90 degrees such that mid-portion 1224 is on a plain that is parallel to the axis of bending moment. Under a loaded condition, the mid-portion 1224 will deform under the bending moment M (see FIG. 6).
Any of the features described in the aforementioned embodiments are not exclusive for any given lift bracket, and may be combined as can be appreciated. The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.

Claims

A lift bracket on an engine for engagement with a lifting apparatus and intended to be used in tandem with a second lift bracket, the lift bracket comprising:
a topmost portion having an opening formed therein, wherein the opening is arranged for engagement with the lifting apparatus, and wherein the topmost portion is substantially flat and defines a first plane;

a base portion having at least one fastener opening for fastening the bracket to the engine, wherein the base portion is substantially flat and lies in the first plane; and

a yield structure disposed between the topmost portion and the base portion and configured for absorbing energy when the second lift bracket on the engine fails, wherein the yield structure includes a mid-portion that defines at least one second plane that is spaced and parallel to the first plane;

wherein when a tensile force is applied to the topmost portion, the yielding structure yields, the topmost portion displaces away from the base portion, and the second plane displaces towards the first plane.
The lift bracket of claim 1, further comprising a first inclined portion disposed between the topmost portion and the mid-portion, wherein the first inclined portion is disposed at an angle α with respect to the first plane, and wherein a first radiused portion connects the topmost portion with the first inclined portion and a second radiused portion connects the first inclined portion with the mid-portion.
The lift bracket of claim 2, further comprising a second inclined portion disposed between the mid-portion portion and the base portion, wherein the second inclined portion is disposed at an angle α with respect to the first plane, and wherein a third radiused portion connects the mid-portion portion with the second inclined portion and a fourth radiused portion connects the second inclined portion with the base portion.
The lift bracket of claim 1, further comprising a spacer disposed on the base portion, wherein the spacer has a central opening aligned with the at least one fastener opening of the base portion, and wherein the spacer is connected to the base portion along an area surrounding the at least one fastener opening.
The lift bracket of claim 1, further comprising a tab that is disposed at an outer edge of the base portion and configured to have an interference fit with the engine for preventing a rotation of the engine with respect to the lift bracket when the second lift bracket fails.
The lift bracket of claim 5, wherein the tab extends substantially perpendicularly away from the first plane.
The lift bracket of claim 5, wherein the tab has a general "hook"-shape and defines a component cavity.
The lift bracket of claim 1 wherein the yield structure comprises a plurality of peaks that are formed alternatively with a plurality of valleys.
The lift bracket of claim 1, further comprising an extension portion formed adjacent to the base portion, wherein the extension forms at least one additional fastener opening.
The lift bracket of claim 1, wherein the topmost portion, the yield structure, and the base portion are integrally formed.
The lift bracket of claim 1, wherein the yield structure comprises a first link and a second link, wherein the first link and the second link surround a slit opening, and wherein the first link meets the second link at a first junction adjacent to the topmost portion and at a second junction adjacent to the base portion.
A lift bracket on an engine for engagement with a lifting apparatus, the lift bracket comprising:
a topmost portion having an opening formed therein, wherein the opening is arranged for engagement with the lifting apparatus, and wherein the topmost portion is substantially flat and defines a first plane and the opening is normal to the first plane;

a generally elongate mid-portion extending from the topmost portion in the first plane;

a base portion having at least one fastener opening for fastening the bracket to the engine, wherein the base portion is substantially flat and defines a second plane that is normal to the first plane and the at least one fastener opening is normal to the second plane, wherein the base portion is generally triangular shaped, with a first side of the triangle abutting the mid-portion.