KR20170140263A - A switching rocker arm assembly having an eccentric shaft for adjusting clearance - Google Patents

Abstract

A switching rocker arm assembly constructed in accordance with one embodiment of the present disclosure includes an outer arm, an inner arm, a bearing axis, and a pivot axle. The outer arm may have a first outer side arm and a second outer side arm. The outer arm may define the outer openings. The inner arm may have a first inner arm and a second inner arm. The inner arm may be disposed between the first outer side arm and the second outer side arm. The inner arms may define inner holes. The bearing shaft can support the bearing. One of the bearing axis and the pivot axis includes a central shaft body having (i) a central centerline, (ii) a first shaft end body having a first centerline, and (iii) a second shaft end body having a second centerline. And the central center line is offset from at least one of the first and second center lines.

Description

A switching rocker arm assembly having an eccentric shaft for adjusting clearance

Cross-reference to related application

This application claims the benefit of U.S. Patent Application No. 62 / 153,004, filed April 27, 2015. The disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to a switching roller finger follower or rocker arm of an internal combustion engine.

Variable valve actuation (VVA) technology has already been introduced and documented. One VVA apparatus includes a variable valve lift (VVL) system, U.S. Patent No. 8,215,275, entitled "Single Lobe Deactivating Rocker Arm ", incorporated herein by reference in its entirety Cylinder deactivation (CDA) system or other valve actuation system as described in U. S. Pat. These mechanisms have been developed to improve performance and fuel economy and / or reduce engine exhaust. Various types of VVA rocker arm assemblies include an internal rocker arm within an outer rocker arm biased by a torsion spring.

The switching rocker arms alternate between latching and unlatching states to control valve operation. The latches move both the inner and outer rocker arms into a single unit when in the latched position. When in the unlatched state, the rocker arms can move independently of each other. In some cases, these arms may engage different cam lobes such as a low-lift lobe, a high-lift lobe, and a lift lobe. Mechanisms are needed to switch the rocker arm modes in a manner that is appropriate for the operation of the internal combustion engine.

The background description provided herein is generally intended to provide context for this disclosure. The work of the presently named inventors is not explicitly or implicitly recognized as prior art to this disclosure, as well as aspects of the technology which may not be prior art at the time of filing, as well as to the extent described in this background section.

A switching rocker arm assembly constructed in accordance with one embodiment of the present disclosure includes an outer arm, an inner arm, a bearing axis, and a pivot axle. The outer arm may have a first outer side arm and a second outer side arm. The outer arm may define the outer openings. The inner arm may have a first inner arm and a second inner arm. The inner arms may be disposed between the first and second outer side arms. The inner arms may define inner holes. The bearing shaft can support the bearing. One of the bearing axis and the pivot axis includes a central shaft body having (i) a central centerline, (ii) a first shaft end body having a first centerline, and (iii) a second shaft end body having a second centerline. And the central center line is offset from at least one of the first and second center lines.

According to further features, the central axis body is positioned between the first and second inner side arms. The center centerline may be offset by the same distance as the preferred mechanical lash adjustment required in the switching rocker arm assembly relative to the first and second centerlines. The first and second center lines are coaxial. The pivot axis is eccentric. The switching rocker arm assembly may further include an elephant foot (e-foot). The e-foot is assembled between the central shaft body of the pivot shaft and the valve. As the pivot axis rotates, the e-foot moves relative to the valve. The pivot axis defines a tool engaging feature on one of the first and second shaft end bodies. The pivot axis secures the inner arm to the outer arm and allows one of the outer and inner arms to rotate about the pivot axis relative to the other of the outer and inner arms when the switching rocker arm assembly is in the inactive state . One of the inner and outer rocker arms defines a passage extending to a corresponding hole for receiving the pivot shaft.

According to another feature, the switching rocker arm may further comprise a stationary member disposed through a passage which, after setting the clearance, secures the pivot shaft relative to one of the inner and outer rocker arms. The fastening member may comprise a flowable plastic configured to solidify. The pivot axis may define an annular groove around one of the first and second shaft end bodies. The fixing member is located in the annular groove.

In one configuration, the bearing axis is eccentric. The bearing is configured to engage the cam lobe. The rotation of the bearing shaft adjusts the mechanical clearance by moving the bearing relative to the cam lobe. The bearing axis is supported at opposite ends by torsion spring ends. One of the inner and outer rocker arms defines the passage. The switching rocker arm may further include a stationary member disposed through a passage that fixes the bearing shaft relative to one of the inner and outer rocker arms after the gap setting. The bearing axis forms an annular groove around one of the first and second shaft end bodies. The fixing member is located in the annular groove.

The rocker arm, which is constructed according to a further shape, comprises an outer arm, a bearing axis and a pivot axis. The outer arm may have a first outer side arm and a second outer side arm, and the outer arm defines outer holes. The bearing shafts can extend through the first and second outer side arms and support the bearings. The pivot axis pivotally supports the outer arm. One of the bearing axis and the pivot axis includes a central shaft body having (i) a central centerline, (ii) a first shaft end body having a first centerline, and (iii) a second shaft end body having a second centerline. And the central center line is offset from at least one of the first and second center lines.

The present disclosure will be more fully understood from the detailed description and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is an exemplary switching rocker arm incorporating a pivot axis constructed in accordance with one embodiment of the present invention, a front perspective view of a switching rocker arm having an exemplary valve and gap adjuster;
Figure 2 is a perspective view of the switching rocker arm of Figure 1 constructed in accordance with an example of the prior art;
Figure 3 is a first perspective view of a pivot axis with an eccentric profile as the pivot axis of Figure 2;
Figure 4 is a second perspective view of the pivot axis of Figure 2;
5 is a sectional view of a pivot shaft, an inner rocker arm and an outer rocker arm according to one embodiment of the present disclosure;
Figure 6 is a side view of the switching rocker arm of Figure 2;
7 is a sectional view of the switching rocker arm of Fig. 6;
8 is an exploded perspective view of an internal rocker arm and an external rocker arm of a switching rocker arm constructed in accordance with another embodiment of the present disclosure;
9 is a perspective view of a roller bearing shaft having an eccentric profile constructed in accordance with another embodiment of the present invention; And
10 is a cross-sectional view of the bearing shaft, the inner rocker arm and the outer rocker arm of Fig. 8;

Referring first to Figures 1 and 2, an exemplary switching rocker arm constructed in accordance with one example of the prior art is shown and identified generally by the reference numeral 10. The switching rocker arm assembly 10 includes duel-feed hydraulic lash adjusters (DFHLA), which are mounted on a piston-driven internal combustion engine and which receive oil from an oil control valve ("OCV" A compact cam-driven single-lobe cylinder deactivation (CDA-1L) switching rocker arm that is operated with a combination of two or more cams 12. The switching rocker arm assembly 10 may be coupled by a single lobe cam 20. [ The switching rocker arm assembly 10 may include an inner arm 22 and an outer arm 24. The default configuration is in a normal lift (latched) position in which the inner arm 22 and the outer arm 24 are secured together to allow the engine valve 26 to open while a standard valve train ), As shown in Fig. The DFHLA 12 has two oil ports. The lower oil port 28 provides gap compensation and is supplied with engine oil similar to a standard HLA. An upper oil port 30, referred to as a switching pressure port, provides a conduit between the controlled hydraulic pressure from the OCV and the latch 32. When the latch 32 is engaged, the inner arm 22 and the outer arm 24 work together as a standard rocker arm to open the engine valve 26. In the no lift (non-latched) position, the inner arm 22 and the outer arm 24 can independently move so that the cylinder is disabled.

A pair of motion loss torsion springs 40 are engaged to maintain continuous contact with the camshaft lobe 20 since the position of the inner arm 22 is biased. The torsion spring 40 is broken by the spring retainer 44 on a mount located on the outer arm 24. [ The spring retainer 44 holds the torsion spring 40 laterally. Exercise torsion spring 40 provides a higher preload than a design using multiple lobes to facilitate continuous contact between inner arm bearing 50 having roller follower 52 and camshaft lobe 20, (preload).

The outer arm 24 may have a first outer side arm 64 and a second outer side arm 66. The inner arm 22 may be disposed between the first outer side arm 64 and the second outer side arm 66. The inner arm 22 includes a first inner side arm 70 and a second inner side arm 72. Both the inner arm 22 and the outer arm 24 are mounted on the pivot shaft 74. The pivot axis 74 may be located near the first end of the rocker arm assembly 10 to allow for a rotational degree of freedom that pivots about the pivot axis 74 when the rocker arm assembly 10 is in the inactive state Thereby fixing the inner arm 22 to the outer arm 24. As described herein, the pivot shaft 74 is pivotally connected to the inner and outer arms 22 (not shown) that adjust the clearance of the rocker arm assembly 10 between the valve 26 and the roller follower 52 24, 24, 24, 24, and 24, respectively.

The bearing 50 and the roller follower 52 are mounted on a bearing shaft 80 that transfers energy from the rotating cam 20 to the rocker arm assembly 10 during normal operation of the rocker arm assembly 10, Is mounted between the side arm (70) and the second inner side arm (72). The bearing shaft 80 is biased upward by the bearing shaft spring 40.

Additional features of the disclosure of the present invention will now be described with reference to Figures 3-7. The mechanical clearance may be mechanically set to a valve tip cap (100). It should be noted that a plurality of valve tip caps 100 having different geometries may be provided. In one configuration, the use of such valve tip cap 100 may be eliminated by the use of pivot shaft 74. In some arrangements, the pivot axis 74 may be used in conjunction with the valve tip cap 100.

The pivot shaft 74 includes a central axis body 110, a first axial end body 112 and a second axial end body 114. The central axis body 110 may be undercut and have a central outer surface 116. The first axial end body 112 and the second axial end body 114 have corresponding first and second center lines 122, 124. The first and second center lines 122 and 124 may be coaxial. The center center line 130 is not coaxial with the first and second center lines 122, 124. In this regard, when the pivot shaft 74 is rotated about the first and second centerlines 122 and 124, the central axis body 110 will only rotate while changing the position of the central outer surface 116. [ In other words, since the central centerline 130 is offset from the first and second centerlines 122 and 124, the central outer surface 116 of the central axis body 110 is spaced apart from the first axis end body 112 and And will move relative to the biaxial end body 114. It will be appreciated that by considering other shapes of the central axis body 110 the central outer surface 116 may be caused to move radially during rotation of the pivot axis 74 about the pivot centerlines 122 and 124 .

As the pivot axis 74 rotates, as the central outer surface 116 moves in position, the e-foot 102 will also move. As the e-foot 102 moves toward the valve 26 and away from the valve 26, the gap can be set. During rotation, the first and second shaft end bodies 112, 114 are positioned within the inner arm holes 132 of the inner rocker arm 122 and the outer arm holes 134 of the outer rocker arm 24 Able to know. The positions of the first and second rocker arms 22, 24 do not change while the pivot shaft 74 rotates. The first axial end body 112 includes a tool engagement groove 140. The tool may engage the tool engagement groove 140 to impart rotational movement on the pivot axis 74 while adjusting the clearance. Although not shown, a similar tool engagement groove may be engaged on the second shaft end body 114. [ The second shaft end body 114 may define the annular groove 142. Once the desired gap is established, the pivot axis 74 can be fixed so as not to further rotate.

Additional features of the disclosure of the present invention will now be described with reference to Figures 2 and 5. The outer rocker arm 24 may define a passage 160 extending from the outer surface 162 of the outer rocker arm 24 to the outer arm hole 134. Once the desired clearance is established, a fastening member in the form of a flexible plastic 170 can be injected through the plastic 160. The plastic 170 solidifies within the bore 134 and around the groove 142 to secure the pivot shaft 74 relative to the outer rocker arm 204 to prevent axial translation of the pivot shaft 74 . More specifically, plastic 170 prevents translational movement of pivot shaft 74 along shafts 122, The plastic 170 also prevents radial movement of the pivot shaft 74 about the axes 122, 124 that prevent rotational motion of the pivot shaft 74. Therefore, the desired gap is fixed. It will be appreciated that once the desired clearance is established, other configurations may be employed to secure the pivot shaft 74 relative to the outer rocker arm 24. [

Turning now to Figures 8-10, a switching rocker arm constructed in accordance with additional features is shown and generally identified by reference numeral 210. [ The switching rocker arm 210 may be configured for use in a CDA-1L as described above with respect to FIG. The switching rocker arm assembly 210 may include an inner arm 222 and an outer arm 224. [ The default configuration is in a normal lift (latched) position in which the inner arm 222 and the outer arm 224 are secured together and allows the cylinder to open as in a standard valve train by opening the engine valve . When the latch 232 is engaged, the inner arm 222 and the outer arm 224 work together as a standard rocker arm to open the engine valve. In the no-lift position, the inner arm 222 and the outer arm 224 can move independently to enable the cylinder to be deactivated. A pair of motion loss torsion springs 240 are always engaged to bias the position of the inner arm 222 to maintain continuous contact with the camshaft lobe (see 20 in FIG. 1). The torsion spring 240 is secured to a mounting portion located on the outer arm 224 by a spring retainer 244. The spring retainer 244 holds the torsion spring 240 laterally. The athletic torsion spring 240 is configured to provide a higher preload than a design using multiple lobes to facilitate continuous contact between the internal arm bearing 250 having the roller follower 252 and the camshaft lobe 220. [ .

The outer arm 224 may have a first outer side arm 264 and a second outer side arm 266. The inner arm 222 may be disposed between the first outer arm 264 and the second outer arm 266. The inner arm 222 may have a first inner side arm 270 and a second inner side arm 272. Both the inner arm 222 and the outer arm 224 are mounted on the pivot shaft 274. The outer arm may be positioned adjacent to the first end of the rocker arm assembly 210 such that the axis 274 may be positioned adjacent the first end of the rocker arm assembly 210 such that when the rocker arm assembly 210 is in the inactive state, While securing the inner arm 222 to the outer arm 224.

The bearing 250 and the roller follower 252 are mounted between the first inner side arm 270 and the second inner side arm 272 on the bearing axis 280 such that the rocker arm assembly 210 is in a normal And serves to transfer energy from the rotation cam 220 to the rocker arm assembly 210. [ The bearing shaft 280 is biased upward by the bearing shaft spring 240. The bearing axis 280 of the rocker arm assembly has an eccentric geometry so that the bearing axis 280 rotates about its central axis within the inner and outer arms 222 and 224 to adjust the clearance of the rocker arm assembly 210 Allow to rotate.

The bearing shaft 280 includes a central shaft body 310, a first axial end body 312 and a second axial end body 314. The central axis body 310 may be undercut and have a central outer surface 316. The first axial end body 312 and the second axial end body 314 have corresponding first and second center lines 322, 324. The first and second centerlines 322 and 324 may be coaxial. The center center line 330 is not coaxial with the first and second center lines 322 and 324. In this regard, when the bearing axis 280 is rotated about the first and second center lines 322 and 324, the central axis body 310 also rotates but rotates while changing the position of the center outer surface 316 Changes the position of the bearing 250 and the final contact position between the bearing 250 and the cam (see 20 in Fig. 1). This movement allows the mechanical clearance of the system to be adjusted and set. In other words, since the centerline 330 is offset from the first and second centerlines 322 and 324, the central outer surface 316 of the central axis body 310 is spaced from the first axis end body 312 and And will move relative to the biaxial end body 314. It will be appreciated that other shapes of the central axis body 310 may be considered that allow the central outer surface 316 to move radially when the bearing axis 280 is rotated about the centerlines 322 and 324.

While the bearing shaft 280 rotates, the first and second shaft bodies 312 and 314 travel around the surface of the bearing shaft spring 240. While the bearing shaft 280 rotates, the position of the first and second rocker arms 222 and 224 does not change, while the relative position of the bearing 250 is changed. The second shaft end body 314 includes a tool engagement groove 340. The tool may engage with the tool engagement groove 340 to impart rotational motion on the bearing axis 280 during gap adjustment. Although not shown, a similar tool engagement groove may be engaged on the second shaft end body 314. The second shaft end body 314 may define an annular groove 342. Once the desired clearance is established, the bearing shaft 280 may be secured to prevent further rotation.

The inner rocker arm 222 may define a passage 360 extending from the outer surface 362 of the inner rocker arm 222 to the bearing shaft hole 364. [ Once the desired gap is established, the fastening member 370 in the form of a flowable plastic can be injected through the passage 360. The plastic 370 can be solidified in the hole 364 and around the groove 342 to secure the bearing shaft 280 relative to the inner rocker arm 222 and to prevent axial movement of the bearing shaft 280 . More specifically, plastic 370 prevents movement of bearing shaft 280 along shafts 280, 324. The plastic 370 also prevents rotational movement of the bearing shafts 280 about the shafts 322 and 324 to prevent radial movement of the bearing shafts 280. Therefore, the desired gap is determined. It will be appreciated that other configurations may be employed to secure the bearing axle 280 relative to the inner rocker arm 222. Although the bearing shaft 280 has been described as part of the switching rocker arm 210, the same principle may be used for the standard rocker arm.

The description of the embodiments has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the present disclosure. The individual elements or features of a particular example are not limited to a specific example in general, and may be used interchangeably where applicable and may be used in selected embodiments even if not specifically indicated or described. The same thing can be diversified in many ways. Such variations are not to be regarded as departures from initiation, and all such variations are intended to be included within the scope of this disclosure.

Claims (38)

A switching rocker arm assembly comprising:
An outer arm having a first outer side arm and a second outer side arm and defining outer holes;
An inner arm having a first inner side arm and a second inner side arm and disposed between the first outer side arm and the second outer side arm and defining inner holes;
Bearing shafts supporting bearings; And
A pivot axis cooperating with said outer arm and said inner arm;
Wherein one of the bearing axis and the pivot axis comprises:
(i) a central axis body having a central centerline,
(ii) a first shaft end body having a first centerline and
(iii) a second axial end body having a second centerline,
Wherein the centerline is offset from at least one of the first and second centerlines. The method according to claim 1,
Wherein the central axis body is located between the first inner side arm and the second inner side arm. 3. The method of claim 2,
Wherein the centerline is offset relative to the first and second centerlines by a distance equal to the desired mechanical gap adjustment required in the switching rocker arm assembly. The method according to claim 1,
Said first and second centerlines being coaxial. 5. The method of claim 4,
Wherein the pivot axis is eccentric. 6. The method of claim 5,
Further comprising an elephant-foot (e-foot)
Wherein the elephant foot is assembled between a central axis body of the pivot axis and a valve, the rotation of the pivot axis causing the elephant foot to move relative to the valve. 6. The method of claim 5,
Wherein the pivot axis defines a tool engagement structure in one of the first and second shaft end bodies. The method according to claim 1,
Wherein the pivot axis secures the inner arm to the outer arm while one of the outer and inner arms is in contact with the other of the outer and inner arms when the switching rocker arm assembly is in the inactive state, And permits a rotational degree of freedom to rotate about an axis. 6. The method of claim 5,
Wherein one of the inner and outer rocker arms defines a passage extending to a corresponding hole for receiving the pivot shaft. 10. The method of claim 9,
Further comprising: a securing member for securing the pivot axis relative to one of the inner and outer rocker arms after setting the gap, wherein the securing member is disposed through the passageway. 11. The method of claim 10,
Wherein the fastening member comprises a flowable plastic configured to solidify. 10. The method of claim 9,
Wherein the pivot axis defines an annular groove about one of the first and second shaft end bodies, the securing member being located within the annular groove. The method according to claim 1,
Wherein the bearing shaft is eccentric. 14. The method of claim 13,
Wherein the bearing is configured to engage a cam lobe and wherein rotation of the bearing axis moves the bearing relative to the cam lobe to adjust the mechanical clearance. 15. The method of claim 14,
Wherein the bearing shaft is supported on the opposite end by a torsion spring end. 15. The method of claim 14,
One of said inner and outer rocker arms defining a passage,
The switching rocker arm comprises:
And a stationary member for securing the bearing shaft relative to one of the inner and outer rocker arms after setting the clearance, wherein the stationary member is disposed through the passage. 17. The method of claim 16,
Wherein the stationary member comprises a flowable plastic configured to solidify. 18. The method of claim 17,
Wherein the bearing axis defines an annular groove around one of the first and second shaft end bodies, and wherein the anchor member is located within the annular groove. A switching rocker arm assembly comprising:
An outer arm having a first outer side arm and a second outer side arm and defining outer holes;
An inner arm having a first inner side arm and a second inner side arm and disposed between the first outer side arm and the second outer side arm and defining inner holes;
Bearing shafts supporting bearings;
A pivot axis cooperating with said outer arm and said inner arm; And
Includes elephant foot (e-foot);
The pivot axis is:
(i) a central axis body having a central centerline,
(ii) a first shaft end body having a first centerline, and
(iii) a second axial end body having a second centerline,
Wherein the central center line is offset from at least one of the first and second center lines, the e-foot is assembled between a central axis body of the pivot axis and a valve, the rotation of the pivot axis relative to the valve Thereby setting the clearance of the switching rocker arm assembly. 20. The method of claim 19,
Wherein the central axis body is located between the first inner side arm and the second inner side arm. 21. The method of claim 20,
Wherein the centerline is offset relative to the first and second centerlines by a distance equal to the desired mechanical gap adjustment required in the switching rocker arm assembly. 20. The method of claim 19,
Said first and second centerlines being coaxial. 23. The method of claim 22,
Wherein the pivot axis is eccentric. 20. The method of claim 19,
Wherein one of the inner and outer rocker arms defines a passage extending to a corresponding hole for receiving the pivot shaft. 25. The method of claim 24,
Further comprising: a securing member for securing a pivot axis relative to one of said inner and outer rocker arms after setting said gap, said securing member being disposed through said passageway. 26. The method of claim 25,
Wherein the stationary member comprises a flowable plastic configured to solidify. 27. The method of claim 26,
The pivot axis defining an annular groove about one of the first and second shaft end bodies, and wherein the securing member is located within the annular groove. A switching rocker arm assembly comprising:
An outer arm having a first outer side arm and a second outer side arm and defining outer holes;
An inner arm having a first inner side arm and a second inner side arm and disposed between the first outer side arm and the second outer side arm and defining inner holes;
Bearing shafts supporting bearings; And
A pivot axis cooperating with said outer arm and said inner arm;
The bearing shafts:
(i) a central axis body having a central centerline,
(ii) a first shaft end body having a first centerline, and
(iii) a second axial end body having a second centerline,
Wherein the centerline is offset from at least one of the first and second centerlines and the bearing is configured to engage a cam lobe, wherein rotation of the bearing axis moves the bearing relative to the cam lobe, Wherein the adjustment mechanism adjusts the clearance of the rocker arm assembly. 29. The method of claim 28,
Wherein the bearing shaft is supported at an opposite end by a torsion spring end. 29. The method of claim 28,
One of said inner and outer rocker arms defining a passage,
The switching rocker arm comprises:
And a stationary member for securing the bearing shaft relative to the one of the inner and outer rocker arms after setting the clearance, wherein the stationary member is disposed through the passage. 31. The method of claim 30,
Wherein the fastening member comprises a flowable plastic configured to solidify. 32. The method of claim 31,
Wherein the bearing axis defines an annular groove around one of the first and second shaft end bodies, and wherein the anchor member is located within the annular groove. A rocker arm assembly comprising:
An outer arm having a first outer side arm and a second outer side arm and defining outer holes;
A bearing shaft extending through the first and second outer side arms and supporting the bearing; And
And a pivot shaft pivotably supporting the outer arm;
Wherein one of the bearing axis and the pivot axis comprises:
(i) a central axis body having a central centerline,
(ii) a first shaft end body having a first centerline, and
(iii) a second axial end body having a second centerline,
The centerline being offset from at least one of the first and second centerlines. 34. The method of claim 33,
Wherein the central axis body is located between the first outer side arm and the second outer side arm. 35. The method of claim 34,
Wherein the centerline is offset with respect to the first and second centerlines by a distance equal to the desired mechanical clearance adjustment required in the rocker arm assembly. 34. The method of claim 33,
Said first and second centerlines being coaxial. 37. The method of claim 36,
Wherein the pivot axis is eccentric. 37. The method of claim 36,
Wherein the bearing shaft is eccentric.

Images