JP2001271620A - Valve deactivator assembly for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a valve deactivator assembly, having a hydraulic lash adjuster having the outer size which will not increase so much, even if valve deactivating function is added. SOLUTION: This valve deactivator assembly is provided with a rocker arm 33, having the pivot position 39 in which the rocker arm 33 is pivotally rotated in response to the rotation of a camshaft 25, and a hydraulic lash adjuster 41 to be operated as a pivot point for the rocker arm 33. A latching mechanism latches an engaging part 69 to a plunger part 67, so as to enable the operation in a normal mode or unlatches the engaging part 69 so as to enable the operation in a deactivating mode.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved valve train for an internal combustion engine, and more particularly, to a valve disabling device assembly used in an internal combustion engine.

[0002]

BACKGROUND OF THE INVENTION The valve nulling device assembly of the present invention can be used to introduce some additional clearance into a valve train so that the valve opens and closes by less than normal opening and closing. Is particularly suitable for introducing sufficient clearance (hereinafter also referred to as "movement") into the valve train to cause the valve to no longer open and close at all (ie, "disable" the valve). . The present invention will be described in this regard.

The general class of valve nulling devices to which the present invention pertains are known for various types of internal combustion engine valve gear trains, including push rod type overhead valve ("OHV") gear trains. The valve nullification device is available with both center pivot rocker arm and end pivot rocker arm overhead cams ("OHC").
Also known are mold valve trains. The particular structure of the present invention is not necessarily limited to use with an OHC end pivot rocker arm type valve gear train, but is particularly suitable for use with this valve gear train and is associated with such a valve gear train. The structure of the present invention will be described.

In a typical valve gear train of the end pivot rocker arm type, the rocker arm pivots about a pivot position formed by itself.
The pivot position engages a ball plunger of an HLA (hydraulic clearance adjuster) disposed within the bore of the cylinder head. In the prior art, HLAs provide some type of valve override function in applications where there is usually enough space in the cylinder head to replace the legacy HLA with a nullification device that typically takes up significantly more space than the traditional HLA. It is known to provide.

[0005]

Unfortunately, in many vehicle applications where it is desirable to have a valve nulling function, there is little space available even with a conventional HLA, and the additional structure may make it more difficult. This is even more so in the case of an enlarged HLA. Additional structures referred to herein typically include, for example, latching the plunger assembly of the HLA to the body for normal operation, or unlatching for operation in a valve disable mode. Then you can make it move,
There is some sort of latching and moving mechanism. It is evident that such additional structure greatly increases the overall size, complexity, and cost of conventional HLA.

For example, in a latching type valve nullification device shown in US Pat. No. 5,655,487, the latching mechanism moves radially under the influence of spring or water pressure to move the body and plunger assembly. A latching member is provided for latching or releasing the latching.
Obviously, in such a valve nulling device, the overall diameter of the device is much larger than the overall diameter of a conventional HLA, which requires only the conventional wall thickness of the body and plunger. Also, the presence of a plunger that must be able to move between the latched and unlatched positions relative to the body increases the overall length required for the bore of the cylinder head, including the HLA body.

Accordingly, an object of the present invention is particularly suitable for use in an end pivot rocker arm type valve gear train in which the external dimensions of the hydraulic clearance adjuster do not increase so much even with the addition of the valve disabling function. A valve nulling device assembly is provided.

[0008] A more specific object of the present invention is to achieve the above-mentioned object, and in particular, to reduce the bore in the cylinder head, which is already required to accommodate a conventional hydraulic clearance adjustment device. It is an object of the present invention to provide such an improved valve nulling device that does not require a large bore.

[0009]

SUMMARY OF THE INVENTION The above and other objects of the present invention are directed to valve means for controlling the flow to and from the combustion chamber, and to open and close the valve means in synchronism with events in the combustion chamber. Implemented by providing a valve nulling device assembly for an internal combustion engine having drive means for providing periodic motion and valve gear means operable to periodically open and close the valve means in response to the periodic motion. Is done. The valve gear means comprises a rocker arm having a valve contact engaging the valve means and a pivot position at which the rocker arm typically pivots in response to a periodic movement of the drive means. The valve nullifier assembly includes a hydraulic lash adjuster disposed within the bore of the cylinder head and serving as a pivot point for the rocker arm pivot position.

The hydraulic lash adjuster features a body member disposed within the bore and a plunger assembly operably associated with the body member and capable of reciprocating with respect to the body member. The plunger assembly includes a plunger portion and an engaging portion surrounding the plunger portion and engaging with a pivot position of the rocker arm. The latching mechanism is operable to latch the engaging portion with respect to the plunger portion at the extended position when operating in the normal mode, and to move the engaging portion when operating in the invalidation mode. The part can be operable to unlatch. The lash adjuster includes means for biasing the engagement portion toward the extended position.

[0011]

Referring now to the drawings, which are not intended to limit the invention, FIG. 1 shows a valve actuated drive train of the end pivot rocker arm type which is particularly suitable for the present invention. ing. FIG. 1 shows a cylinder head 11 forming a flow path 13, through which a flow to and from the combustion chamber generally designated 15 is present.

The flow to or from the combustion chamber 15 is controlled by an engine poppet valve 17 biased by a valve spring 19 from an open position to a closed position shown in FIG. Poppet valve 1
7 comprises a valve seat 21 which, when the poppet valve 17 is closed, engages a valve seat insert, not shown here but well known to those skilled in the art.

The camshaft 25 has a cam profile generally designated 27 which forms a base circle 29 and an overhang 31. As is well known to those skilled in the art, the function of the camshaft 25 is to generate a periodic motion that opens and closes the engine poppet valve 17 in time with events in the combustion chamber 15.

The periodic movement of the camshaft 25 is controlled by a rocker arm 33, here shown as an end pivot type rocker arm, by the engine poppet valve 17.
Is transmitted to By comparing FIG. 1 and FIG. 3, it can be seen that the view of the rocker arm 33 is an axial sectional view of the rocker arm 33. Rocker arm 33 includes a valve contact (“pad”) 35 that engages the upper end of the stem of poppet valve 17. Rocker arm 33
Also includes a rotatable cam follower 37 mounted on a shaft 38 to remain engaged with the cam profile 27.

Finally, the rocker arm 33 is pivoted (hereinafter also referred to as "39"), that is, the rocker arm 33 normally engages the cam follower 37 alternately with the base circle portion 29 and the overhang portion 31. A pivot portion, generally designated 39, which forms a position for pivoting as it rotates. In the present embodiment, this is merely an example,
The pivot portion 39 has a rocker arm 33 having a pair of sidewalls 40, each sidewall forming a generally semi-circular support surface 40s best shown in FIG. The support surface 40s of the pivot portion 39 has an H generally designated 41 in FIGS.
LA (hydraulic lash adjuster) is engaged.

Referring now primarily to FIG. 2, it will be appreciated that the rocker arm 33 and the hydraulic lash adjuster 41 together comprise a valve nullifier assembly generally designated 43. The cylinder head 11 forms a bore 45 extending on the upper surface of the cylinder 11 itself. The head 11 also forms an oil passage 47 that normally communicates with the engine lubricating oil cycle. As will be appreciated by those skilled in the art, the oil passage 47 provides one "source of pressurized fluid" necessary to operate the HLA 41 in a conventional manner well known to those skilled in the art of hydraulic lash adjusters. Have.

The hydraulic clearance adjuster 41 includes a generally cylindrical body 49 disposed within the bore 45 and forming an internal blind bore 51. A plunger assembly, generally designated 53, is slidably disposed within the blind bore 51 and includes an upper plunger element 55, a lower plunger element 57, and a leak down plunger 58.
It has. The plunger elements 55, 57, 58 cooperate to form a low pressure chamber 59 (hereinafter also referred to as a "reservoir"). Blind bore 51 and leak down plunger element 58 cooperate to form a high pressure chamber, also designated by reference numeral "51" for simplicity of illustration, and shown in FIG. ing.

The check valve assembly, generally designated 61, operates to allow fluid communication between the reservoir 59 and the high pressure chamber 51 in a manner generally well known to those skilled in the art. be able to. Although the present invention is shown with reference to a "conventional leak-down" type of HLA, it is to be understood that the present invention is not necessarily so limited, and that the present invention can be used with various other types of HLA. . Although the present invention is shown with respect to a type of HLA having a movable plunger assembly disposed within a stationary body member, it should be understood that the present invention is not so limited. By way of example only, and within the scope of the present invention, the movable plunger assembly may surround the stationary body member. All that matters in the present invention is that there is a body member and that there is a plunger assembly that can move (reciprocate) relative to the body member.

Still referring primarily to FIG. 2, the body 49 defines a fluid port 63 that communicates with the oil passage 47 in an open flow path. Upper plunger element 55 includes a radial bore 65 in open communication with port 63.
So that pressurized fluid can flow from passage 47 through port 63 and bore 65. The lower plunger element 57 has a lower plunger member 5 at the upper end.
7 forms an axially extending passage 66p in communication with a port 66 near the upper end of port 7, so that the low pressure fluid in oil passage 47 flows through passage 66p and then to port 6p.
6 and into the low pressure chamber 59.

The cylinder head 11 is disposed on the left side of FIG. 2 of the HLA 41, and forms an oil passage 11c which is in fluid communication with an engine oil periodic passage different from the periodic passage connected to the oil passage 47. I have. Oil passage 11c
Has the "source of pressurized fluid" necessary to control (actuate) the valve nullifier assembly 43 of the present invention. Therefore, as is well known to those skilled in the art of engine hydraulics, the oil pressure in passage 11c must be controlled to selectively produce a relatively low or relatively high pressure. By way of example only, passage 11
The pressure in c can be controlled by a solenoid valve (not shown here). The body 49 includes a generally cylindrical member 4 that can have a roll pin or similar structure.
9 m form an opening in which they are arranged. Member 49m
Extends radially inward and into the opening 55o formed by the upper plunger element 55, thus substantially preventing rotation of the element 55 relative to the body 49. The lower plunger element 57 forms another axially extending passage 57p by which
The control pressure in passage 11c can flow through member 49m, then through opening 55o, and then through passage 57p for reasons described below.

In a conventional HLA, the upper plunger element 5
5 is provided with a ball plunger which engages the adjacent surface of the rocker arm. According to one important aspect of the invention, the upper plunger element 55 surrounds the independent plunger part 67 (only the upper end of the element 55) and the cylindrical plunger part 67 with respect to the plunger part 67 ( FIG.
(In the vertical direction), and an engaging portion generally designated by 69. A compression (moving) spring 71 surrounds the lower part of the plunger 67,
As shown in FIG. 2, it is operable to bias the engagement portion 69 upwards toward a fully extended position.

In the fully extended position described above and shown in FIGS. 2 and 4, the engagement 69 is biased and the engagement 69
Engages a snap ring (retaining clip) 72 that limits upward movement of the The engaging portion 69 is engaged with the pivot portion 39, and as will be described in detail below, when the valve invalidating device assembly is in an effective (latching) mode (refer to FIG. 2). Disable vertical movement. When the slide engagement portion 69 is engaged with the snap ring 72, a part of the force applied by the moving spring 71 is directly transmitted to the snap ring 72, that is, all the force of the spring 71 is applied to the rocker arm 33. is not. Instead, the force transmitted to rocker arm 33 is approximately equal to the force applied to upper plunger member 55 by the pressure in high pressure chamber 51.

Next, as can be seen mainly with reference to FIG. 4, the upper plunger element 55 has a radially extending one.
Ends in one or more bores 79 and defines an axially extending passage 75 in open communication with the bore. A generally block-shaped portion (best seen in FIG. 3) of the engaging portion 69 surrounds the plunger portion 67, and a pair of generally cylindrical latching housing portions 81 are arranged in opposite directions from the block-shaped portion. Extending. Furthermore, the latching housing portion 81 has a fulcrum of the surface 40s of the rocker arm 33 as best seen in FIG.
Each latching housing portion 81 has a bore 7 when the engagement portion is in the extended position shown in FIGS.
9 to form a radially extending bore 83. Each bore 83 is sealed at its radially outer end by a plug 88. A latching pin 85 is disposed in each bore 83 so as to be able to reciprocate there, and the latching pin 85 is moved by a compression (latching) spring 89 toward the latching position shown in FIG. It is biased and the radially outer ends of the springs 89 are in contact with the respective plugs 85.

A pair of pistons 91 are disposed in the bore 79, and in the latched state shown in FIG. 4, the pistons 91 are radially inwardly moved by the latching pins 87 under the influence of the latching spring 89. And can be engaged with each other. In this latched state, the latching pin 87 is biased radially inward into the bore 79 as shown in FIG. 4, so that the engaging portion 69 is latched to the plunger 67. In order to realize this latched state, a relatively low pressure fluid is applied to the control pressure source 11c.
The spring 89 is selected to be able to overcome the force of the low pressure fluid acting on the radially inner surface of the piston 91 as the spring 89. Therefore, the spring 89 includes the latching pin 87 and the piston 91
To the latched position in the figure. In the latched state, the fulcrum formed by the latch housing 81 remains in the position shown in FIGS. 1, 2 and 4, whereby the pivot 39 of the rocker arm 33 pivots but moves vertically. do not do. Rocker arm 33
Is a camshaft 25 as is well known to those skilled in the art.
Operates as usual in response to the periodic movement of the engine poppet valve 17 to move the engine poppet valve 17 between the open and closed positions.

When it is desired to operate in the valve invalidation mode, first, the fluid pressure at the control pressure source 11c is increased to a relatively high pressure, that is, the piston 91 is moved radially outward against the force of the latching spring 89. It must be increased to a pressure sufficient to bias. The piston 91 is biased outward by a distance sufficient to disengage the latching pin 87 from the bore 79 so that the engaging portion 69 is
7 is released from latching. In other words, the engaging portion 6
9 is no longer fixed with respect to the plunger part 67 and can therefore move freely downwardly away from the snap ring 72 against the force of the movement spring 71. As will be appreciated by those skilled in the art, when the cam follower 37 is engaged with the base circle portion 29 of the camshaft 25, sufficient force acts on the engagement portion 69 to overcome the motion spring 71. Never. However, the valve spring 19 is considerably stronger than the detent spring 71, so that the overhang 31 of the cam profile is
3, a downward force acting on the rocker arm 33 is overcome, overcoming the movement spring 71 and moving the pivot portion 39 downward as shown in FIG. In the above-described valve invalid state, the rocker arm 33 pivots around the pad portion 35, but the poppet valve 17 does not move due to the force of the valve spring 19.

Therefore, the present invention provides a cylinder head 1
It can be seen that a valve nulling device assembly can be provided which allows the use of a conventional size hydraulic clearance adjuster of the required size of the bore in one. Unlike the known prior art, all the mechanisms required to deactivate the valve are located outside the main part of the HLA and the plunger section 6 is located in an area where more than normal space is available.
7 only.

[Brief description of the drawings]

FIG. 1 is a somewhat schematic partial cross-sectional view of an internal combustion engine of a vehicle, illustrating a typical valve gear train of the type that can be used with the present invention.

FIG. 2 is a greatly enlarged partial cross-sectional view taken along line 2-2 of FIG. 1 showing the valve nullifier assembly of the present invention in a normal latched condition;

FIG. 3 is a partial perspective view similar to FIG. 1, showing the valve gear train including the valve nullification device assembly of the present invention in an unlatched state;

FIG. 4 is a further enlarged partial sectional view similar to FIG. 2, showing the valve nullification device of the present invention in the latched state in detail.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Cylinder head 11c Oil passage 13 Flow path 15 Combustion chamber 17 Engine poppet valve 19 Valve spring 21 Valve pressure 25 Cam shaft 27 Cam profile 29 Base circle part 31 Overhang part 33 Rocker arm 35 Valve contact part 37 Cam follower 38 Shaft 39 pivot Part 40 Side wall 40s Support surface 41 HLA (hydraulic lash adjuster) 43 Valve nullification device assembly 45 Bore 47 Oil passage 49 Cylindrical body 51 Internal blind bore 53 Plunger assembly 55 Upper plunger element 55o Opening 57 Lower plunger element 57p passage 58 leak-down plunger 59 low-pressure plunger 61 check valve assembly 63 fluid port 65 bore 66 port 66p passage 67 plunger section 69 engaging section 71 pressure The spring 72 snap ring 75 passageway 79 bore 81 latching housing section 83 bore 85 plug 87 latching pin 89 compression spring 91 piston

 ──────────────────────────────────────────────────続 き Continuation of front page (71) Applicant 390033020 Eaton Center, Cleveland and Ohio 44114, U.S.A. S. A. (72) Inventor Richard Lee Madden 122, Marshall Elk Street, Michigan 49068

Claims (7)

[Claims] 1. Valve means (17) for controlling the flow to and from the combustion chamber (15);
A drive means (25) for providing a periodic movement to open and close the valve means (17) in time with an event in the combustion chamber (15); and a periodic movement of the valve means (17) in response to the periodic movement. A valve gearing device for an internal combustion engine, the valve gearing device being operable to open and close the valve contact portion, wherein the valve gearing means engages with the valve means (17). 35)
And a pivot position (39) at which the rocker arm (33) typically pivots in response to the periodic movement of the drive means (25).
The valve nullification device assembly (43).
Is disposed in a bore (45) of the cylinder head (11), and the rocker arm (3)
3) The valve nullification device assembly (43) including a hydraulic lash adjuster (41) serving as a pivot point for the pivot position (39), wherein the body member (43) disposed in the bore (45). A plunger assembly (53) operably associated with said body member (49) and capable of reciprocating with respect to said body member (49);
7) and a plunger assembly (5) including an engaging portion (69) surrounding the plunger portion (67) and engaging the pivot position (39) of the rocker arm (33).
3) and when operating in the normal mode, the engaging portion (69) can be operated to be latched with respect to the plunger portion at the extended position, and when operating in the invalidation mode. A latching mechanism (79 to 91) operable to unlatch the engaging portion (69) with respect to the plunger portion (67), and the engaging portion (69) is extended. Means for biasing toward a position (71). 2. The drive means comprises a camshaft (25) forming a cam profile having a base circle (29) and an overhang (31), wherein the rocker arm (33) is a cam follower. The valve nullification device assembly of claim 1, comprising (37). 3. The pivot position (39) of the rocker arm (33) engages with the engaging portion (69), and when the latching mechanism is in the normal latching state, the plunger portion (39). 67) having a pair of sidewalls (40) located adjacent to the upper end of the latch mechanism (79 to 91) when operating in the nullification mode.
Is in the latch release state, the drive means (25) exerts a force opposing the force of the means (71) on the rocker arm (33), and the engaging portion (6)
The valve nullifier assembly according to claim 1, wherein the upper end of the plunger portion (67) extends between the sidewalls (40) to bias 9) toward the extended position. 4. The cylinder head (11) is operatively associated with the latching mechanism (79-91) and operates to bias the latching mechanism toward the unlatched state. A spring means (89) operable to bias the latching mechanism toward the latched state. The valve nullifier assembly of claim 1, comprising: 5. The plunger assembly (53) includes a flow path (57) in open communication with the pressurized control fluid source (11c).
p), and the plunger part (67) is provided with the latch mechanism (79 to 9) from the flow path (57p).
The valve nullification device assembly according to claim 4, wherein the flow channel (75) is formed to allow open flow communication from 1). 6. The engagement portion (69) and the plunger portion (67) cooperate to align the bore (79) when the engagement portion (69) is in the extended position. , 83)
Wherein the latching mechanism is biased radially inward and latches into the plunger portion (67) when the pressurized control fluid source (11c) contains a relatively low pressure fluid. 6. The valve nullifier assembly of claim 5, comprising a pair of diametrically opposed latching pins (87). 7. The plunger section (67) is disposed in a generally radial bore (79) and in the radial bore (79), and includes the pressurized control fluid source (1).
In response to the relatively high pressure fluid in 1c), it is deflected radially outward to move the latching pin (87) radially outward to release latch engagement with the plunger portion (67). 7. A valve nullifier assembly according to claim 6, wherein the valve nullifier is formed with a pair of pistons (91) operable as described above.