ENGINE VALVE LIFTER ANTI-ROTATION DEVICE

Abstract

An engine roller lifter for use in a valve train of an internal combustion engine includes a body, an anti-rotation device and a clip. The body can have an outer peripheral surface configured for sliding movement in a bore provided in the engine. The body can define a receiving channel formed in the outer peripheral surface. The body can further define a slot formed at the receiving channel. The anti-rotation device can include a guide plug received in the receiving channel of the body. The guide plug can extend outwardly from the outer peripheral surface of the body. The guide plug can be configured to locate into a bore slot defined in a cylinder head of the internal combustion engine. The clip can be received by the slot and captured the guide plug in the receiving channel.

Description

FIELD

The present disclosure relates generally to hydraulic lash adjusting tappets of the type having a roller follower for contacting a cam shaft in an internal combustion engine valve train.

BACKGROUND

Roller lifters can be used in an engine valvetrain to reduce friction and as a result provide increased fuel economy. In other advantages, a roller lifter can open a valve quicker and for a longer period of time than a flat tappet lifter. In this regard, airflow can be attained quicker and longer increasing the ability to create power.

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

An engine roller lifter for use in a valve train of an internal combustion engine includes a body, an anti-rotation device and a clip. The body can have an outer peripheral surface configured for sliding movement in a bore provided in the engine. The body can define a receiving channel formed in the outer peripheral surface. The body can further define a slot formed at the receiving channel. The anti-rotation device can include a guide plug received in the receiving channel of the body. The guide plug can extend outwardly from the outer peripheral surface of the body. The guide plug can be configured to locate into a bore slot defined in a cylinder head of the internal combustion engine. The clip can be received by the slot and captured the guide plug in the receiving channel.

According to additional features, the clip can include a C-clip. The guide plug can include a first and second lobed body portion. The first lobed body portion is keyed in the receiving channel to preclude radial movement of the guide plug. The second lobed body portion can extend radially outwardly beyond the outer peripheral surface of the body. The second lobed body portion can include a pair of parallel sidewalls. The guide plug can be cold-formed. The guide plug can further include an extension portion having a finger thereon. The finger can be configured to prevent rotation of the C-clip. The body can further include a groove and a connecting channel formed into the peripheral surface. The body can further include a transverse passage. Oil collected in the groove can flow to the connecting channel and into the transverse passage to lubricate a roller bearing disposed on the roller lifter.

An engine roller lifter for use in a valve train of an internal combustion engine according to additional features of the present disclosure can include a body, an anti-rotation device and a coupling arrangement. The body can have an outer peripheral surface configured for sliding movement in a bore provided in the engine. The body can define a receiving channel formed in the outer peripheral surface. The anti-rotation device can include a guide plug having a first and second lobed body portion. The first lobed body portion can be configured to be slidably received in the receiving channel of the body in an installed position. The second lobed body portion can extend outwardly from the outer peripheral surface of the body. The second lobed body portion can be configured to locate into a bore slot defined in a cylinder head of the internal combustion engine and inhibit rotation of the guide plug and body. The coupling arrangement can couple the anti-rotation device at the receiving channel.

According to additional features, the body can further include a groove and a connecting channel formed into the peripheral surface. The body can further include a transverse passage. Oil collected in the groove can flow to the connecting channel and into the transverse passage to lubricate a roller bearing disposed on the roller lifter.

In other features, the coupling arrangement can comprise a set screw. In another configuration, the coupling arrangement can comprise a clip received by a slot defined in the body. The clip can capture the guide plug in the receiving channel. In other configurations, the coupling arrangement can comprise annealing. The body can be locally annealed in an area around the guide plug. A circumferential edge area that defines an entrance to the channel can be annealed and shaped inwardly to close a circumference and trap the guide plug within the channel.

According to other configurations, the coupling arrangement can comprise staking, wherein the guide plug can be staked relative to the body. The first lobed body portion can be axially compressed and expanded radially forming an interference fit with the receiving channel of the body. In another configuration, the coupling arrangement comprises resistance welding. In yet another configuration, the coupling arrangement comprises laser welding.

An engine roller lifter for use in a valve train of an internal combustion engine includes a body and an anti-rotation device. The body can have an outer peripheral surface configured for sliding movement in a bore provided in the engine. The body can define a receiving channel formed in the outer peripheral surface. The anti-rotation device can include a guide plug having a first body portion and a second body portion. The first body portion can be formed in a geometrical shape complementary for receipt into the receiving channel. The guide plug can be formed of a smart memory alloy. Subsequent to positioning the guide plug into the receiving channel, the engine roller lifter can be heat treated setting the shape of the guide plug to retain the guide plug in an installed position within the receiving channel. The second body portion extends outwardly from the outer peripheral surface of the body. The second body portion can be configured to locate into a bore slot defined in a cylinder head of the internal combustion engine and inhibit rotation of the guide plug and body.

According to other features, the body further defines a slot formed at the receiving channel. A clip can be received by the slot. The clip captures the guide plug in the receiving channel. The clip can be formed of smart memory alloy such that heat treating sets the clip in the slot. The body can further include a groove and a connecting channel formed into the peripheral surface. The body further includes a transverse passage. Oil collected in the groove flows to the connecting channel and into the transverse passage to lubricate a roller bearing disposed on the roller lifter.

BRIEF DESCRIPTION OF THE DRAWINGS

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

FIG. 1 is a roller lifter constructed in accordance to one example of the present disclosure and shown in an exemplary Type V valve train arrangement;

FIG. 2 is a side perspective view of a roller lifter constructed in accordance to one example of prior art;

FIG. 3 is a front perspective view of the roller lifter of FIG. 2 and shown with a retaining clip in exploded view;

FIG. 4 is a side perspective view of a roller lifter including a roller lifter body and a guide plug constructed in accordance to one example of the present teachings;

FIG. 5 is a detail perspective view of the guide plug of the roller lifter of FIG. 4;

FIG. 6 is a schematic illustration of a guide plug according to another example of the present disclosure;

FIG. 7 is a top view of a guide plug constructed in accordance to another example of the present disclosure and shown retained in a roller lifter body with a C-clip;

FIG. 8 is a side perspective view of the roller lifter body of FIG. 7;

FIG. 9 is a side perspective view of the guide plug of FIG. 7; and

FIG. 10 is a detail view of an interface between the guide plug and an opposing bore slot in a cylinder head of an engine.

DETAILED DESCRIPTION

With initial reference to FIG. 1, a roller lifter constructed in accordance to one example of the present disclosure is shown and generally identified at reference number 10. The roller lifter 10 is shown as part of a Type V arrangement. It will be appreciated that while the roller lifter 10 is shown in a Type V arrangement, the roller lifter 10 may be used in other arrangements within the scope of the present disclosure. In one non-limiting example, the present teachings can also be applied to a fuel pump actuator. In this regard, the features described herein associated with the roller lifter 10 can be suitable to a wide variety of applications. A cam lobe 12 indirectly drives a first end of a rocker arm 14 with a push rod 16. It will be appreciated that in some configurations, such as an overhead cam, the roller lifter 10 may be a direct link between the cam lobe 12 and the rocker arm 14. A second end of the rocker arm 14 actuates a valve 20. As the cam lobe 12 rotates, the rocker arm 14 pivots about a fixed shaft 22. The roller lifter 10 is in contact with, and follows the cam 12 through a conventional roller bearing or roller follower 24, such as a needle roller bearing type. Those skilled in the art will appreciate that the present disclosure is not limited to any particular roller follower design, or for example, whether the axle of the roller is provide with needle bearings or merely a bushing.

The roller lifter 10 is configured to reciprocate along its axis within a lifter-receiving hole 26 formed in engine block 28. A clearance 29 can be defined between the receiving hole 26 and the roller lifter 10. As will become appreciated herein, pressurized engine oil can flow from an engine oil passage P formed in the engine block 28, around the clearance 29 and into a groove 44 formed around the roller lifter. The groove 44 can act as an oil reservoir to provide lubrication for the roller follower 24.

With initial reference to FIGS. 2 and 3, a roller lifter 10A according to one example of prior art is shown and will be described. The roller lifter 10A generally includes a body 30A, having a leakdown assembly 32A received within the body 30A. A roller bearing 34A is rotatably mounted to the body 30A. An anti-rotation assembly 36A includes a guide plug 38A and a retaining clip 40A. The body 30A includes an outer peripheral surface 42A configured for sliding movement in a bore (not specifically shown) provided in an engine block or cylinder head of an internal combustion engine. The body 30A includes a groove 50A and a pair of concave recess portions 52A formed therein and inset from the outer peripheral surface 42A. The guide plug 38A includes a pair of cylindrical sections 54A that extend from a central body portion 56A.

The retaining clip 40A generally includes a ring body 60A having an anti-rotation protrusion 62A extending therefrom. The anti-rotation protrusion 62A extends radially beyond the outer peripheral surface 42A of the body 30A in an installed position. The anti-rotation protrusion 62A is configured to locate or key in a corresponding bore slot (not specifically shown) in the cylinder head for inhibiting rotation of the roller lifter about a longitudinal axis during operation. The retaining clip 40A can be snap fit into the groove 50A to capture the guide plug 38A. Specifically, the pair of cylindrical sections 54A can locate into the corresponding concave recess portions 52A formed in the body 30A. In the assembled position, the pair of cylindrical sections 54A can protrude radially beyond the outer peripheral surface 42A of the body 30A and key in the corresponding bore slot of the cylinder head.

Turning now to FIGS. 4-6, the roller lifter 10 constructed in accordance to one example of the present teachings will be described. The roller lifter 10 generally includes a body 30, having a leakdown assembly 32 received within the body 30. The roller follower 24 (FIG. 1) is rotatably mounted to the body 30. An anti-rotation device 36 includes a guide plug 38 secured to the body 30 with at least one of a set screw 39 and/or a C-clip 40 (FIG. 6). The body 30 includes an outer peripheral surface 42 configured for sliding movement in a bore slot (see for example bore slot 158, FIG. 10) provided in a cylinder head of an internal combustion engine. A groove 44 is formed around the outer peripheral surface 42. The body 30 includes a receiving channel 50 formed therein and inset from the outer peripheral surface 42 configured to receive the guide plug 38.

The guide plug 38 includes a first and a second lobed body portion 52 and 54, respectively. The first lobed body portion 52 is configured to be slidably received into the receiving channel 50 of the body 30. The first lobed body portion 52 will key into the channel 50 to preclude radial movement of the guide plug 38. A slot 60 is defined in the body 30 at the channel 50 for receiving the C-clip 40. The C-clip 40 can retain the guide plug 38 within the channel 50 and preclude axial movement of the guide plug 38.

The second lobed body portion 54 extends radially beyond the outer peripheral surface 42 of the body 30 in an installed position. The second lobed body portion 54 is configured to locate or key in a corresponding bore slot (see for example bore slot 158, FIG. 10) in the cylinder head for inhibiting rotation of the roller lifter about a longitudinal axis during operation.

The body 30 includes a connecting channel 70 formed therein. The connecting channel 70 can be inset from the outer peripheral surface 42. The connecting channel 70 fluidly connects with a transverse passage 74. Oil that leaks down around the peripheral surface 42 of the body 30 (between the body 30 and the bore of the engine block) can be captured into the groove 44. From the groove 44, oil can flow into the connecting channel 70, through the transverse passage 74 to lubricate the roller bearing 34.

Turning now to FIGS. 7-10, a roller lifter 110 constructed in accordance to another example of the present teachings will be described. The roller lifter 110 generally includes a body 130, having a leakdown assembly 132 received within the body 130. A roller bearing (see FIG. 1) is rotatably mounted to the body 130. An anti-rotation device 136 includes a guide plug 138 secured to the body 130 with a C-clip 140 (FIG. 7). The body 130 includes an outer peripheral surface 142 configured for sliding movement in a bore (see for example bore slot 158, FIG. 10) provided in a cylinder head or engine block of an internal combustion engine. The body 130 includes a channel 150 formed therein and inset from the outer peripheral surface 142 configured to receive the guide plug 138.

The guide plug 138 includes a first and a second lobed body portion 152 and 154, respectively. The first lobed body portion 152 is configured to be slidably received into channel 150 of the body 130 in a direction generally upward as viewed in FIG. 8. The first lobed body portion 152 will key into the channel 150 to preclude radial movement of the guide plug 138. A slot 160 is defined in the body 130 at the channel 150 for receiving the C-clip 140. The C-clip 140 can retain the guide plug 138 within the channel 150 and preclude axial movement of the guide plug 138. In one example, the guide plug 138 is cold formed.

The second lobed body portion 154 extends radially beyond the outer peripheral surface 142 of the body 130 in an installed position. The second lobed body portion 154 can have a pair of parallel sidewalls 156. The second lobed body portion 154 is configured to locate or key in a corresponding bore slot 158 (FIG. 10) in a cylinder head 159 for inhibiting rotation of the roller lifter about a longitudinal axis during operation. An extension portion 162 can be formed on the guide plug 138. The extension portion 162 can be the result of a forming process for the guide plug 138 such as cold form material overflow. Explained further, the dies used in cold forming can be designed to allow a bulge to form at one end of the guide plug 138. The extension portion 162 can further include a finger 164 (FIG. 9) configured to prevent rotation of the C-clip 140 that retains the guide plug 138 further improving reliability.

The body 130 includes a connecting channel 170 and an outer groove 172 (FIG. 8) formed therein. The connecting channel 170 and the outer groove 172 can be inset from the outer peripheral surface 142. The connecting channel 170 fluidly connects the outer groove 172 with a transverse passage 174. Oil can flow between the connecting channel 170 and the outer groove 172 and to the transverse passage 174 to lubricate the roller bearing (see FIG. 1).

According to other features of the present disclosure, additional coupling arrangements and/or joining techniques may be provided for retaining the guide plug 138 within the channel 150 of the body 130 of the roller lifter 110. In one example, the body 130 of the roller lifter 110 can be locally annealed in an area around the guide plug 138. In some examples, once the metal of the guide plug 138 is softened, it can be shaped or formed toward the guide plug 138 to retain the guide plug 138 within the channel 150. Additionally or alternatively, a circumferential edge area 180 that defines an entrance to the channel 150 can be annealed and shaped inwardly to close the circumference and trap the guide plug 138 within the channel 150.

In other examples, the guide plug 138 can be staked relative to the body 130 of the roller lifter 110. When staking, the guide plug 138 can attain an interference fit in the channel of the body 130. In one non-limiting example, the guide plug 138 can be slidably inserted into the channel 150. Once inserted, a tool such as a staking punch can be used to axially compress the guide plug 138. Axial compression can cause the outer surfaces of the first lobed body portion 152 (and the second lobed body portion 154) to expand radially forming an interference fit with the channel 150 of the body 130. A permanent joint can result that retains the guide plug 138 into the channel 150.

In other configurations, the guide plug 138 can be resistance welded to the body 130 in the channel 150. Other welding operations such as laser welding can be used as well to couple the guide plug 138 to the body 130. It will be appreciated that the additional joining techniques described above can be equally applied to the other configurations disclosed herein such as to the guide plug 38 and body 130 of roller lifter 10. Furthermore, in some examples multiple joining techniques disclosed herein may be used in concert to capture the guide plug to the body of the roller lifter.

According to additional features of the present disclosure, various components of the roller lifter, guide plug and/or clip can be formed of shape or smart memory alloy (SMA). In general SMA's are metals that can “remember” their original or parent shape. SMA's are Martensitic crystal materials that can be molded, then plastically deformed, and then heat treated to return to the desired shape. Once inserted, the guide plug 138 can be heat treated. As used herein, the terms “heat treated” and “heat treating” are used to denote raising the temperature of the SMA above the transition temperature to restore the SMA to its original or parent shape. By way of non-limiting example, some SMA's include nickel-titanium (Ni—Ti, or nitinol), copper, zinc and aluminum alloy (Cu—Zn—Al); copper, aluminum and nickel (Cu—Al—Ni); iron, manganese and silicon (Fe—Mn—Si). Other SMA's may be used within the scope of the present disclosure.

In one configuration, with reference to the examples show in FIGS. 7-9, the guide plug 138 may be formed of SMA. While the following discussion will be made in reference to the guide plug 138, a guide plug may be formed of SMA having other similar geometries within the scope of the present disclosure. It will be appreciated that the guide plug may be originally formed or molded in a shape consistent to the desired “installed” shape for the given channel 150.

In one configuration, the guide plug 138 can be introduced into the channel 150 of the body 130. In some examples the guide plug 138 may be plastically deformed prior to insertion into the channel 150. Elevating the temperature of the guide plug 138 causes it to take its original shape. In this regard, heat treating sets the shape of the guide plug 138 in an installed position within the channel 150. It is appreciated that the roller lifter 110 and guide plug 138 may be heated in concert causing the SMA guide plug 138 to be set in an installed position within the channel 150. The guide plug 138 can attain a tolerance or clearance fit relative to the channel 150 in the installed position fixing the guide plug 138 into the channel 150. This example eliminates the requirement of a supplemental retaining device (such as the c-clip 140). Moreover, such a configuration eliminates the requirement of special tooling for installation of the guide plug 138 as there is no press-fit during installation.

In another example, the c-clip 140 may be formed of SMA. Again, the c-clip 140 can be originally formed or molded in a shape consistent to the desired “installed” shape relative to the body 130. A guide plug 138 can be introduced into the channel 150 of the body 130 and the c-clip 140 (or other supplemental retaining mechanism) subsequently located. The c-clip 140 can be heat treated causing it to take its original shape attaining a fixed relationship with the body 130 and securing the guide plug 138 in the channel 150. Again, in some examples the whole assembly (roller lifter 110, guide plug 138 and c-clip 140) may be heated together with the understanding that the SMA components will react appropriately to the heat treatment. It is further appreciated that more than one piece may be formed of SMA. For example, the guide plug 138 and the c-clip 140 may both be formed of SMA and arranged in geometries to cooperatively “return” to their original shape in a coupled relationship subsequent to heat treatment.

The foregoing description of the examples 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 example are generally not limited to that particular example, but, where applicable, are interchangeable and can be used in a selected example, 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

1. An engine roller lifter for use in a valve train of an internal combustion engine, the engine roller lifter comprising: a body having an outer peripheral surface configured for sliding movement in a bore provided in the engine, the body defining a receiving channel formed in the outer peripheral surface, the body further defining a slot formed at the receiving channel;an anti-rotation device including a guide plug received in the receiving channel of the body, the guide plug extending outwardly from the outer peripheral surface of the body, the guide plug configured to locate into a bore slot defined in a cylinder head of the internal combustion engine; anda clip received by the slot and capturing the guide plug in the receiving channel.

2. The engine roller lifter of claim 1 wherein the clip is a C-clip.

3. The engine roller lifter of claim 2 wherein the guide plug includes a first and a second lobed body portion.

4. The engine roller lifter of claim 3 wherein the first lobed body portion is keyed in the receiving channel to preclude radial movement of the guide plug.

5. The engine roller lifter of claim 4 wherein the second lobed body portion extends radially outwardly beyond the outer peripheral surface of the body.

6. The engine roller lifter of claim 5 wherein the second lobed body portion includes a pair of parallel sidewalls. The engine roller lifter of claim 6 wherein the guide plug is cold-formed.

8. The engine roller lifter of claim 7 wherein the guide plug further includes an extension portion having a finger thereon, the finger configured to prevent rotation of the C-clip.

9. The engine roller lifter of claim 1 wherein the body further includes a groove and a connecting channel formed into the peripheral surface, the body further including a transverse passage, wherein oil collected in the groove flows to the connecting channel and into the transverse passage to lubricate a roller bearing disposed on the roller lifter.

10. An engine roller lifter for use in a valve train of an internal combustion engine, the engine roller lifter comprising: a body having an outer peripheral surface configured for sliding movement in a bore provided in the engine, the body defining a receiving channel formed in the outer peripheral surface;an anti-rotation device including a guide plug having a first and second lobed body portion, the first lobed body portion configured to be slidably received in the receiving channel of the body in an installed position, the second lobed body portion extending outwardly from the outer peripheral surface of the body, the second lobed body portion configured to locate into a bore slot defined in a cylinder head of the internal combustion engine and inhibit rotation of the guide plug and body; anda coupling arrangement that couples the anti-rotation device at the receiving channel.

11. The engine roller lifter of claim 10 wherein the body further includes a groove and a connecting channel formed into the peripheral surface, the body further including a transverse passage, wherein oil collected in the groove flows to the connecting channel and into the transverse passage to lubricate a roller bearing disposed on the roller lifter.

12. The engine roller lifter of claim 10 wherein the coupling arrangement comprises a set screw.

13. The engine roller lifter of claim 10 wherein the coupling arrangement comprises a clip received by a slot defined in the body, the clip capturing the guide plug in the receiving channel.

14. The engine roller lifter of claim 10 wherein the coupling arrangement comprises annealing, wherein the body is locally annealed in an area around the guide plug.

15. The engine roller lifter of claim 14 wherein a circumferential edge area that defines an entrance to the channel is annealed and shaped inwardly to close a circumference and trap the guide plug within the channel.

16. The engine roller lifter of claim 10 wherein the coupling arrangement comprises staking, wherein the guide plug is staked relative to the body.

17. The engine roller lifter of claim 16 wherein the first lobed body portion is axially compressed and expanded radially forming an interference fit with the receiving channel of the body.

18. The engine roller lifter of claim 10 wherein the coupling arrangement comprises resistance welding.

19. The engine roller lifter of claim 10 wherein the coupling arrangement comprises laser welding.

20. An engine roller lifter for use in a valve train of an internal combustion engine, the engine roller lifter comprising: a body having an outer peripheral surface configured for sliding movement in a bore provided in the engine, the body defining a receiving channel formed in the outer peripheral surface, the body further defining a slot formed at the receiving channel, a groove and a connecting channel formed into the outer peripheral surface, the body further including a transverse passage, wherein oil collected in the groove flows to the connecting channel and into the transverse passage to lubricate a roller bearing disposed on the roller lifter;an anti-rotation device including a guide plug having a first and second lobed body portion, the first lobed body portion configured to be slidably received in the receiving channel of the body in an installed position, the second lobed body portion extending outwardly from the outer peripheral surface of the body, the second lobed body portion configured to locate into a bore slot defined in a cylinder head of the internal combustion engine and inhibit rotation of the guide plug and body; anda clip received by the slot and capturing the guide plug in the receiving channel.

21. An engine roller lifter for use in a valve train of an internal combustion engine, the engine roller lifter comprising: a body having an outer peripheral surface configured for sliding movement in a bore provided in the engine, the body defining a receiving channel formed in the outer peripheral surface; andan anti-rotation device including a guide plug having a first body portion and a second body portion, the first body portion formed in a geometrical shape complementary for receipt into the receiving channel, the guide plug being formed of a smart memory alloy wherein subsequent to positioning of the guide plug into the receiving channel, heat treating the engine roller lifter sets the shape of the guide plug to retain the guide plug in an installed position within the receiving channel such that the second body portion extends outwardly from the outer peripheral surface of the body, the second body portion configured to locate into a bore slot defined in a cylinder head of the internal combustion engine and inhibit rotation of the guide plug and body.

22. The engine roller lifter of claim 21 wherein the body further defines a slot formed at the receiving channel, the engine roller lifter further comprising: a clip received by the slot and capturing the guide plug in the receiving channel.

23. The engine roller lifter of claim 22 wherein the clip is formed of smart memory alloy such that heat treating sets the clip in the slot.

24. The engine roller lifter of claim 21 wherein the body further includes a groove and a connecting channel formed into the peripheral surface, the body further including a transverse passage, wherein oil collected in the groove flows to the connecting channel and into the transverse passage to lubricate a roller bearing disposed on the roller lifter.