WO2015050754A1

WO2015050754A1 - Switching roller finger follower latch pin anti-rotation device

Info

Publication number: WO2015050754A1
Application number: PCT/US2014/057106
Authority: WO
Inventors: David Robert HOSKINS
Original assignee: Eaton Corporation
Priority date: 2013-10-04
Filing date: 2014-09-24
Publication date: 2015-04-09
Also published as: US20160215658A1; CN104791034A; CN204476490U

Abstract

A switching rocker arm according to one example of the present disclosure includes an outer arm, an inner arm, a latch and a sleeve. The inner arm can be pivotally secured to the outer arm and have a latch bore. The latch can have a distal end portion and a proximal end portion. The distal end portion can include a latch flat. The sleeve can be one-piece and have a sleeve body that defines a sleeve bore having a sleeve flat. The latch can be received by the sleeve body. The latch flat can be keyed to the sleeve flat.

Description

SWITCHING ROLLER FINGER FOLLOWER LATCH PIN ANTI-ROTATION DEVICE

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Patent Application No. 61/886,797 filed on October 4, 2013 and U.S. Patent Application No. 62/040,683 filed on August 22, 2014. The disclosures of the above applications are incorporated herein by reference.

FIELD

[0002] The present disclosure relates generally to switching roller finger followers or rocker arms in internal combustion engines.

BACKGROUND

[0003] A switching roller finger follower or rocker arm allows for control of valve actuation by alternating between two or more states. In some examples, the rocker arm can include multiple arms, such as an inner arm and an outer arm. In some circumstances, these arms can engage different cam lobes, such as low-lift lobes, high- lift lobes, and no-lift lobes. Mechanisms are required for switching rocker arm modes in a manner suited for operation of internal combustion engines.

[0004] The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.

SUMMARY

[0005] A switching rocker arm according to one example of the present disclosure includes an outer arm, an inner arm, a latch and a sleeve. The inner arm can be pivotally secured to the outer arm and have a latch bore. The latch can have a distal end portion and a proximal end portion. The distal end portion can include a latch flat. The sleeve can be one-piece and have a sleeve body that defines a sleeve bore having a sleeve flat. The latch can be received by the sleeve body. The latch flat can be keyed to the sleeve flat.

[0006] According to additional features, the sleeve bore can be D-shaped. The latch flat and the sleeve flat can cooperate to inhibit rotation of the latch relative to the sleeve. The latch and the sleeve can be received by the latch bore of the inner arm. The distal end portion can further include an arm engaging surface.

[0007] A switching rocker arm according to another example of the present disclosure can include an outer arm, an inner arm, a latch and a sleeve. The inner arm can be pivotally secured to the outer arm and have a latch bore. The latch can have a distal end portion and a proximal end portion. The distal end portion can include a latch slot. The sleeve can have a sleeve body that extends from a first end to a second end and defines an inner diameter and an outer diameter. The inner diameter of the sleeve body can have an integrally formed key thereon. The latch can be received by the sleeve body. The key of the sleeve body can be keyed to the latch slot.

[0008] According to additional features, the key can extend an axial length of the sleeve from the first end to the second end. The key can extend a distance less than an entire axial length of the sleeve. The key can be positioned closer to the first end than the second end. The key can extend from the first end toward the second end and terminate at an intermediate location on the inner diameter between the first and second ends.

[0009] According to other features, the key can have a square cross-sectional profile. The key can have a circular cross-section. The latch slot and the key can cooperate to inhibit rotation of the latch relative to the sleeve. The latch and the sleeve can be received by the latch bore of the inner arm. The distal end portion can further include an arm engaging surface.

[0010] A switching rocker arm according to another example of the present disclosure can include an outer arm, an inner arm, a latch and an integrally formed sleeve. The inner arm can be pivotally secured to the outer arm and have a latch bore. The latch can have a distal end portion and a proximal end portion. The distal end portion can have a latch slot. The integrally formed sleeve can have a sleeve body that extends from a first end to a second end. The sleeve body can define an inner diameter and an outer diameter. The inner diameter can have a key formed thereon. The key can extend from the first end toward the second end and terminate at an intermediate location on the inner diameter between the first and second ends. The latch can be received by the sleeve body. The key of the sleeve body can be keyed to the latch slot.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein:

[0012] FIG. 1 is a front perspective view of an exemplary switching rocker arm constructed in accordance to one example of the present disclosure;

[0013] FIG. 2 is a front perspective view of a latch sleeve of the switching rocker arm of FIG. 1 according to a first example;

[0014] FIG. 3 is an end view of the latch sleeve of FIG. 2;

[0015] FIG. 4 is a front perspective view of a latch pin of the switching rocker arm of FIG. 1 ;

[0016] FIG. 5 is an end view of the latch pin of FIG. 4 shown with the latch sleeve of FIG. 2;

[0017] FIG. 6A is a front perspective view of a latch sleeve constructed in accordance to a second example of the present disclosure;

[0018] FIG. 6B is a front perspective view of a latch sleeve constructed in accordance to a third example of the present disclosure;

[0019] FIG. 6C is a front perspective view of a latch sleeve constructed in accordance to a fourth example of the present disclosure;

[0020] FIG. 7 is a front perspective view of a latch sleeve constructed in accordance to a fifth example of the present disclosure;

[0021] FIG. 8 is an end view of the latch sleeve of FIG. 7;

[0022] FIG. 9 is a front perspective view of a latch pin constructed in accordance to a second example of the present disclosure

[0023] FIG. 10 is an end view of the latch pin of FIG. 9 and shown with the latch sleeve of FIG. 7; [0024] FIG. 1 1 is a cross-sectional view of the latch pin and latch sleeve of FIG. 10 taken along lines 1 1 -11 ;

[0025] FIG. 12 is a front perspective view of a latch pin constructed in accordance to a third example of the present disclosure;

[0026] FIG. 13 is a front perspective view of a latch sleeve constructed in accordance to a sixth example of the present disclosure; and

[0027] FIG. 14 is a front perspective view of the latch pin of FIG. 12 and the latch sleeve of FIG. 13.

DETAILED DESCRIPTION

[0028] With initial reference to FIG. 1 , an exemplary switching rocker arm constructed in accordance to one example of the present disclosure is shown and generally identified at reference 10. The switching rocker arm 10 can include a three lobed cam 12, a lash adjuster 14, a valve 16, a spring 20 and a spring retainer 22. The cam 12 can have a first and second high-lift lobe 26, 28 and a low-lift lobe 30. The switching rocker arm 10 has an outer arm 40 and an inner arm 42. During operation, the high-lift lobes 26 and 28 contact the outer arm 40 while the low-lift lobe 30 contacts the inner arm 42. The lobes cause periodic downward movement of the outer arm 40 and the inner arm 42. The downward motion is transferred to the valve 16 by the inner arm 42, thereby opening the valve 16. The rocker arm 10 is switchable between a high-lift mode and a low-lift mode. In the high-lift mode, the outer arm 40 is latched to the inner arm 42.

[0029] During engine operation, the high lift lobes 26 and 28 periodically push the outer arm 40 downward. Because the outer arm 40 is latched to the inner arm 42, the high-lift motion is transferred from the outer arm 40 to the inner arm 42 and further to the valve 16. When the rocker arm 10 is in its switched mode, the outer arm 40 is not latched to the inner arm 42. As a result, high-lift movement exhibited by the outer arm 40 is not transferred to the inner arm 42. Instead, the low-lift lobe 30 contacts the inner arm 42 and generates low-lift motion that is transferred to the valve 16. When unlatched from the inner arm 42, the outer arm 40 pivots about an axle 50, but does not transfer motion to the valve 16. It will be appreciated that the rocker arm 10 is provided by way of example only. In this regard, the configuration of the rocker arm 10 is not limited to the configuration of the rocker arm 10 shown in FIG. 1. In this regard, it will be appreciated that the rocker arm 10 can be configured to have the outer arm normally latched to the inner arm or unlatched to the inner arm depending on configuration and/or application.

[0030] With additional reference to FIGS. 2-5, the rocker arm 10 can include a mechanism 60 (FIG. 1 ) for latching the inner arm 42 to the outer arm 40. The mechanism 60 can include a latch pin 70 (FIG. 4) and a sleeve 72 (FIGS. 2 and 3). The mechanism 60 is configured to be mounted inside a bore 78 of the inner arm 42. The sleeve 72 can have a sleeve body 74 that defines a D-shaped bore 80 having a sleeve flat 82. The sleeve 72 according to the present disclosure is one-piece. In one example the sleeve flat 82 can be formed on the sleeve body 74 from a first end 84 of the sleeve body 74 to a second end 86 of the sleeve body 74. The latch pin 70 can be received by the sleeve body 74. The latch pin 70 can include a latch pin body 90 that extends along a longitudinal axis 92. The latch pin body 90 can have a distal end portion 100 and a proximal end portion 1 10. The distal end portion 100 can include an arm engaging surface 1 14. In the latched state, the arm engaging surface 1 14 of the latch pin 70 engages a latch engaging surface of the outer arm 40. The distal end portion 100 can further include a latch flat 120. In the assembled position (FIG. 5), the latch flat 120 of the latch pin 70 is keyed to the sleeve flat 82 of the sleeve 72. In this regard, the latch flat 120 of the latch pin 70 and the sleeve flat 82 of the sleeve 72 cooperate to inhibit rotation of the latch pin 70 about its longitudinal axis 92.

[0031] Turning now to FIGS. 6A to FIG. 1 1 , a plurality of sleeves will be described that can each be used in combination with a latch pin 70' having a slot 122' (FIG. 9). With reference now to FIG. 6A, a sleeve 132A constructed in accordance to additional features is shown. The sleeve 132A can generally include a sleeve body 134A having an outer diameter 136A and an inner diameter 138A. A key 140A can be integrally formed with the sleeve body 134A on the inner diameter 138A. The sleeve 132A is one-piece or integrally formed. In this regard, assembly steps required for coupling a separate key to the sleeve are avoided reducing cost and assembly time. The key 140A can extend generally axially along the entire inner diameter 138A from a first end 142A of the sleeve body 134A to a second end 144A of the sleeve body 134A. The key 140A can be configured to engage the slot 122' of latch pin 70'. In this regard, the slot 122' of the latch pin 70' and the key 140A of the sleeve 132A cooperate to inhibit rotation of the latch pin 70' about its axis 92'.

[0032] With reference now to FIG. 6B, a sleeve 132B constructed in accordance to additional features is shown. The sleeve 132B can generally include a sleeve body 134B having an outer diameter 136B and an inner diameter 138B. A key 140B can be integrally formed with the sleeve body 134B on the inner diameter 138B. The sleeve 132B is one- piece or integrally formed. In this regard, assembly steps required for coupling a separate key to the sleeve are avoided reducing cost and assembly time. The key 140B can extend generally axially along a portion of the inner diameter 138B from a position spaced from a first end 142B of the sleeve body 134B to a position spaced from a second end 144B of the sleeve body 134B. In one configuration, the key 140B can be positioned closer to the first end 142B than the second end 144B. In the example shown, the key 140B can have a generally square cross-sectional profile. The key 140B can be configured to engage the slot 122' of latch pin 70'. In this regard, the slot 122' of the latch pin 70' and the key 140A of the sleeve 132A cooperate to inhibit rotation of the latch pin 70' about its axis 92'.

[0033] With reference now to FIG. 6C, a sleeve 132C constructed in accordance to additional features is shown. The sleeve 132C can generally include a sleeve body 134C having an outer diameter 136C and an inner diameter 138C. A key 140C can be integrally formed with the sleeve body 134C on the inner diameter 138C. The sleeve 132C is one- piece or integrally formed. In this regard, assembly steps required for coupling a separate key to the sleeve are avoided reducing cost and assembly time. In the example shown, the key 140C can have a generally circular cross-sectional profile. In one configuration, the key 140B can be positioned closer to a first end 142C of the sleeve body 134C than a second end 144C of the sleeve body 134C. The key 140C can be configured to engage the slot 122' of latch pin 70'. In this regard, the slot 122' of the latch pin 70' and the key 140C of the sleeve 132C cooperate to inhibit rotation of the latch pin 70' about its axis 92'.

[0034] Turning now to FIGS. 7-1 1 , a sleeve 152 constructed in accordance to additional features is shown. The sleeve 152 can generally include a sleeve body 154 having an outer diameter 156 and an inner diameter 158. The key 160 can be integrally formed with the sleeve body 154 on the inner diameter 158. The sleeve 152 is one-piece or integrally formed. In this regard, assembly steps required for coupling a separate key to the sleeve are avoided reducing cost and assembly time. The key 160 can extend partially along an axial length of the sleeve body 154. In the example shown, the key 160 can extend from a first end 162 of the sleeve body 154 toward a second end 164 of the sleeve body. The key 160 can terminate at an intermediate location on the inner diameter 158 between the first and second ends 162 and 164. The key 160 can be configured to engage a slot 122' on a latch pin 70' (FIG. 9). In this regard, the latch slot 122' of the latch pin 70' and the key 160 of the sleeve 72 cooperate to inhibit rotation of the latch pin 70' about its longitudinal axis 92'. The latch pin 70' can be constructed similarly to the latch pin 70 illustrated in FIG. 4. The latch pin 70' can include a distal end portion 100' and a proximal end portion 1 10', however does not include the latch flat 120.

[0035] FIG. 12 illustrates a latch pin 270 constructed in accordance to additional features. The latch pin 270 can be similar to the latch pin 170 shown in FIG. 4 however a latch flat 320 is smaller than the latch flat 120. Explained differentially, the latch flat 320 occupies a reduced radial profile as compared to the latch flat 120 on the latch pin 70 of FIG. 4. The latch pin 270 can include a distal end portion 300 and a proximal end portion 310. The distal end portion 300 can include an arm engaging surface 314. In the latched state, the arm engaging surface 314 of the latch pin 270 engages a latch engaging surface of the outer arm 40. The latch flat 320 can be formed on the distal end portion 300. The latch pin 270 can extend along a longitudinal axis 292.

[0036] Turning now to FIGS. 13 and 14, a sleeve 352 constructed in accordance to additional features is shown. The sleeve 352 can be one-piece or integrally formed. The sleeve 352 can generally include a sleeve body 354 having an outer diameter 356 and an inner diameter 358. A key or latch flat 360 can be formed on the inner diameter 358. The key 360 can extend entirely (or partially) along an axial length of the sleeve body 354. The key 360 can be configured to engage the latch flat 320 on a latch pin 270 (FIG. 12). In this regard, the latch flat 320 of the latch pin 270 and the key or latch flat 360 of the sleeve 352 cooperate to inhibit rotation of the latch pin 270 about its longitudinal axis 292. [0037] The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.

Claims

CLAIMS What is claimed is:

1 . A switching rocker arm comprising:

an outer arm;

an inner arm pivotally secured to the outer arm and having a latch bore; a latch having a distal end portion and a proximal end portion, the distal end portion including a latch flat; and

a one-piece sleeve having a sleeve body that defines a sleeve bore having a sleeve flat, wherein the latch is received by the sleeve body and the latch flat is keyed to the sleeve flat.

2. The switching rocker arm of claim 1 wherein the sleeve bore is D-shaped.

3. The switching rocker arm of claim 2 wherein the latch flat and the sleeve flat cooperate to inhibit rotation of the latch relative to the sleeve.

4. The switching rocker arm of claim 3 wherein the latch and sleeve are received by the latch bore of the inner arm.

5. The switching rocker arm of claim 1 wherein the distal end portion further includes an arm engaging surface.

6. A switching rocker arm comprising: an outer arm;

an inner arm pivotally secured to the outer arm and having a latch bore; a latch having a distal end portion and a proximal end portion, the distal end portion including a latch slot; and a sleeve having a sleeve body that extends from a first end to a second end and defines an inner diameter and an outer diameter, the inner diameter of the sleeve body having an integrally formed key thereon, wherein the latch is received by the sleeve body and the key of the sleeve body is keyed to the latch slot.

7. The switching rocker arm of claim 6 wherein the key extends an axial length of the sleeve from the first end to the second end.

8. The switching rocker arm of claim 6 wherein the key extends a distance less than an entire axial length of the sleeve.

9. The switching rocker arm of claim 8 wherein the key is positioned closer to the first end than the second end.

10. The switching rocker arm of claim 8 wherein the key extends from the first end toward the second end and terminates at an intermediate location on the inner diameter between the first and second ends.

1 1. The switching rocker arm of claim 6 wherein the key has a square cross- sectional profile.

12. The switching rocker arm of claim 6 wherein the key has a circular cross- section.

13. The switching rocker arm of claim 6 wherein the latch slot and the key cooperate to inhibit rotation of the latch relative to the sleeve.

14. The switching rocker arm of claim 6 wherein the latch and sleeve are received by the latch bore of the inner arm.

15. The switching rocker arm of claim 6 wherein the distal end portion further includes an arm engaging surface.

16. A switching rocker arm comprising: an outer arm;

an inner arm pivotally secured to the outer arm and having a latch bore; a latch having a distal end portion and a proximal end portion, the distal end portion including a latch slot; and

an integrally formed sleeve having a sleeve body that extends from a first end to a second end and defines an inner diameter and an outer diameter, the inner diameter having a key formed thereon, wherein the key extends from the first end toward the second end and terminates at an intermediate location on the inner diameter between the first and second ends;

wherein the latch is received by the sleeve body and the key of the sleeve body is keyed to the latch slot.

17. The switching rocker arm of claim 16 wherein the key has a square cross- sectional profile.

18. The switching rocker arm of claim 16 wherein the latch slot and the key cooperate to inhibit rotation of the latch relative to the sleeve.

19. The switching rocker arm of claim 16 wherein the latch and sleeve are received by the latch bore of the inner arm.

20. The switching rocker arm of claim 16 wherein the distal end portion further includes an arm engaging surface.