US20090266319A1

US20090266319A1 - System and method for providing hydraulic valve lash compensation for electrically actuated internal combustion engine poppet valves

Info

Publication number: US20090266319A1
Application number: US12/110,809
Authority: US
Inventors: James Douglas Ervin
Original assignee: Ford Global Technologies LLC
Current assignee: Ford Global Technologies LLC
Priority date: 2008-04-28
Filing date: 2008-04-28
Publication date: 2009-10-29

Abstract

A system and method for assembling an electrical valve actuator to a cylinder head is described. The system and method provide for lower assembly cost, improved concentricity between valve actuator armatures and valve stems, as well enabling lower inertia valve actuators.

Description

FIELD

The present description relates to a system and method for providing hydraulic lash adjustment for an internal combustion engine having at least one electrically actuated poppet valve.

BACKGROUND

A system for assembling a hydraulically dampened electrical valve actuator to the cylinder head of an internal combustion engine is described in U.S. Pat. No. 6,354,253. This patent describes an electrical valve actuator having an armature return spring and hydraulic lash adjuster located on different sides of the valve actuator armature plate. The valve actuator appears to be built into the cylinder head above a poppet valve. Individual actuator components are inserted into the cylinder head piece by piece and bolted to cylinder head flanges to anchor the assembled actuators in place.
The above-mentioned system can also have several disadvantages. For example, if the valve actuator is in need of inspection, the entire valve actuator has to be disassembled from the cylinder head. Further, the design has inherently high mass because the valve return spring requires that the armature extend beyond the armature plate, thereby increasing the armature inertia and limiting the actuator response. Further still, because the actuator appears to be installed in pieces, it may be difficult to ensure concentricity between the actuator armature, the hydraulic lash adjuster, and the valve stem.
The inventor herein has recognized the above-mentioned disadvantages and has developed a system and method that offers substantial improvements.

SUMMARY

One embodiment of the present description includes a system for mounting an electrical valve actuator to an internal combustion engine, the system comprising: an electrical actuator for operating a poppet valve that controls flow to a cylinder of an internal combustion engine; a cylinder head having at least a poppet valve for directing flow into a cylinder of said internal combustion engine; and a guide block located between said electrical actuator and said cylinder head, said guide block comprising a lash adjuster bore beginning at a first face of said guide block and ending at a location that is at least partially through said guide block, said lash adjuster bore diameter sized to allow the body of a hydraulic lash adjuster to slide through said lash adjuster bore in an axial direction, said lash adjuster bore aligned with a coaxially situated counter bore that extends from said lash adjuster bore to a second face of said guide block. This system overcomes at least some disadvantages of the above-mentioned system.
The assembly of electrical valve actuators to cylinder heads of an internal combustion engine can be improved by using a guide block. A guide block can be designed such that a counter bore in the block acts as a pilot during assembly of electric valve actuators to cylinder heads. As a result, the pilot structure improves concentricity between subassemblies (e.g., valve actuators and cylinder heads) and allows components to be separately assembled and then brought together as desired. Further, subassemblies can reduce the time necessary to inspect valve actuators. In addition, a counter bored guide block also allows the electrical actuator to be designed such that the armature plate and stem form a T structure and reduce the overall mass of the valve actuator.
The present description can provide several advantages. For example, the above-mentioned system can reduce valve actuator and valve stem wear by improving concentricity between moving parts. Further, a guide block can act as an enabler toward reducing actuator mass, thereby leading to improved valve actuator response time. Further still, a guide block can reduce assembly time of subassemblies by providing an efficient means for locating and fastening electrical actuators to a cylinder head.
The above advantages and other advantages, and features of the present description will be readily apparent from the following Detailed Description when taken alone or in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The advantages described herein will be more fully understood by reading an example of an embodiment, referred to herein as the Detailed Description, when taken alone or with reference to the drawings, wherein:

FIG. 1 is a schematic diagram of an engine having electrically actuated valves, and its control system;

FIG. 2 a is a flowchart of an example method for assembling an electrically actuated valve to a cylinder head of an internal combustion engine;

FIG. 2 b is a flowchart of an alternative example method for assembling an electrically actuated valve to a cylinder head of an internal combustion engine;

FIG. 3 a is a schematic of an example valve actuator guide block positioned before attachment to an internal combustion cylinder head;

FIG. 3 b is a schematic of an electrical valve actuator before assembled to an internal combustion engine cylinder head by way of a guide block;

FIG. 3 c is a schematic of an electrical valve actuator after assembly to an internal combustion engine cylinder head;

FIG. 4 a is a schematic of an example of an alternate guide block that is attached to the electrical valve actuator before the electrical actuator in attached to the cylinder head of an internal combustion engine;

FIG. 4 b is a schematic of a guide block and electrical actuator assembly prior to installation to a cylinder head of an internal combustion engine;

FIG. 4 c is a schematic of a guide block and electrical actuator assembly installed to a cylinder head of an internal combustion engine;

FIG. 5 a is an example lash adjuster having an integral annulus deployed in a guide block lash adjuster bore; and

FIG. 5 b is an example lash adjuster deployed in a guide block that has an integral annulus.

DETAILED DESCRIPTION

Referring to FIG. 1, internal combustion engine 10, comprising a plurality of cylinders, one cylinder of which is shown in FIG. 1, is controlled by electronic engine controller 12. Engine 10 includes combustion chamber 30 and cylinder walls 32 with piston 36 positioned therein and connected to crankshaft 40. Combustion chamber 30 is known communicating with intake manifold 44 and exhaust manifold 48 via respective intake valve 52 an exhaust valve 54.
Each intake and exhaust valve is operated by an electromechanically controlled valve coil and armature assembly 51 and 53. Valve actuators 51 and 53 are mounted to cylinder head 25 via guide blocks 58 and 59. In an alternative embodiment, exhaust valves may be mechanically actuated while intake valves are electrically actuated.
Intake manifold 44 is also shown having fuel injector 66 coupled thereto for delivering liquid fuel in proportion to the pulse width of signal FPW from controller 12. Fuel is delivered to fuel injector 66 by fuel system (not shown) including a fuel tank, fuel pump, and fuel rail (not shown). Alternatively, the engine may be configured such that the fuel is injected directly into the engine cylinder, which is known to those skilled in the art as direct injection. In addition, intake manifold 44 is shown communicating with optional electronic throttle 125.
Distributorless ignition system 88 provides ignition spark to combustion chamber 30 via spark plug 92 in response to controller 12. Universal Exhaust Gas Oxygen (UEGO) sensor 76 is shown coupled to exhaust manifold 48 upstream of catalytic converter 70. Alternatively, a two-state exhaust gas oxygen sensor may be substituted for UEGO sensor 76. Two-state exhaust gas oxygen sensor 98 is shown coupled to exhaust pipe 73 downstream of catalytic converter 70. Alternatively, sensor 98 can also be a UEGO sensor. Catalytic converter temperature is measured by temperature sensor 77, and/or estimated based on operating conditions such as engine speed, load, air temperature, engine temperature, and/or airflow, or combinations thereof.
Converter 70 can include multiple catalyst bricks in one example. In another example, multiple emission control devices, each with multiple bricks, can be used. Converter 70 can be a three-way type catalyst in one example.
Controller 12 is shown in FIG. 1 as a conventional microcomputer including: microprocessor unit 102, input/output ports 104, and read-only-memory 106, random-access- memory 108, 110 Keep-alive-memory, and a conventional data bus. Controller 12 is shown receiving various signals from sensors coupled to engine 10, in addition to those signals previously discussed, including: engine coolant temperature (ECT) from temperature sensor 112 coupled to water jacket 114; a position sensor 119 coupled to a accelerator pedal; a measurement of engine manifold pressure (MAP) from pressure sensor 122 coupled to intake manifold 44; a measurement (ACT) of engine air amount temperature or manifold temperature from temperature sensor 117; and a engine position sensor from sensor 118 sensing crankshaft 40 position. Sensor 118 may be a variable reluctance, Hall effect, optical, or magneto-resistive sensor. Alternatively, a camshaft position sensor may also be provided and may be used to determine engine position. In a preferred aspect of the present description, engine position sensor 118 produces a predetermined number of equally spaced pulses every revolution of the crankshaft from which engine speed (RPM) can be determined.
Storage medium read-only memory 106 can be programmed with computer readable data representing instructions executable by processor 102 for performing the methods described below as well as other variants that are anticipated but not specifically listed.
Referring now to FIG. 2 a, a flow chart of an example method for assembling an electrical valve actuator to a cylinder head of an internal combustion engine is shown. The present method describes attaching a valve block guide to a cylinder head and then attaching an electrical actuator to the guide block and cylinder head.
The guide block design may take different forms depending on the actuator design and the cylinder head design. In one embodiment, the guide block has a bore designed to house a hydraulic lash adjuster that extends from one face of the guide block partially through the guide block. A counter bore beginning at a guide block face opposite the guide block face where the lash adjuster bore is initiated extends to the lash adjuster bore so that the electrical actuator armature stem and poppet valve stems can be in communication through the guide block. The lash adjuster bore diameter is sized to allow the body of a hydraulic lash adjuster to slide through the lash adjuster bore in an axial direction and may be aligned with a coaxially situated counter bore.
At step 201, the lash adjuster guide block is aligned to a cavity in the cylinder head. The lash adjuster guide block includes an oil gallery for providing lubricating oil to a hydraulic lash adjuster that slides in a lash adjuster bore that begins at one face of the guide block and extends at least partially through the guide block. The guide block oil gallery is oriented such that it will interface to an oil gallery in the cylinder head when the guide block is mated to the cylinder head. When the guide block is positioned for installation, the guide block lash adjuster bore is closer to the cylinder head than the guide block counter bore.
It should also be mentioned that the lash adjuster guide block lash adjuster bore may be smooth or it may include an annulus. If a smooth bore block lash adjuster bore is used, an annulus is formed in the hydraulic lash adjuster tappet body. The annulus forms an oil reservoir between the lash adjuster and the guide block. The annulus also reduces the wetted area in close proximity to the guide block bore which can reduce viscous friction. Lubricating oil is distributed between the guide block lash adjuster bore and the hydraulic lash adjuster as movement of the electrical valve actuator causes the lash adjuster to slide within the guide block lash adjuster bore. On the other hand, if an annulus is cut or formed in the guide block the tappet body is made uniform in the area where the tappet body interfaces to the guide block. The guide block annulus provides the same function described above, but moving the annulus to the guide block allows the guide block height to be shortened, whereas tappet height can be reduced by forming the annulus in the tappet body. The description of FIG. 5 provides a description for selecting the location of an annulus.
At step 203, the guide block is mated and attached to the cylinder head. In one embodiment, bolts are used to anchor the guide block to the cylinder head although other known fastening means are also anticipated.
At step 205, the hydraulic lash adjuster is installed to the guide block. The hydraulic lash adjuster is dropped into the guide block lash adjuster bore via a counter bore that extends from the guide block lash adjuster bore to the guide block face that is opposite to the guide block face where the guide block lash adjuster bore is initiated. The lash adjuster may be loaded by hand or by an automated means.
At step 207, an electrical actuator is installed above the lash adjuster guide block. The lash adjuster guide block improves the interface between the electrical actuator and cylinder head by performing several functions. Namely, the lash adjuster guide block allows an electrical actuator assembly to be installed at the cylinder head rather than having to install several components to the cylinder head. This can reduce the amount of time necessary to inspect a valve. Further, the guide block can serve to help locate the electrical actuator. Specifically, the counter bore provides a socket into which the electrical actuator return spring is located. The assembler places the armature return spring and stem of the electrical actuator into the counter bore and engages the hydraulic lash adjuster tappet body. Since the actuator return spring diameter increases from the end of the actuator armature to the actuator core, the return spring acts to center the armature stem with respect to the counter bore and lash adjuster bore. The electrical actuator is directed toward the cylinder head until the actuator encounters the cylinder head or guide block.
At step 209, the electrical actuator is fastened to the cylinder head or guide block. The guide block may be wider or narrower than the valve actuator depending on design criteria. So in some designs, the actuator will be mounted directly to the cylinder head, while in other designs, the actuator will be mounted to the guide block. Once the electrical actuator is mounted, an electrical connection is made between the actuator and a power electronics controller.
Referring now to FIG. 2 b, a flow chart of an alternative example method for assembling an electrical valve actuator to a cylinder head of an internal combustion engine is shown. The present method describes a method for attaching a valve block guide to an electrical valve actuator and then installing the assembly to a cylinder head. In this embodiment, the lash adjuster guide block is designed to be assembled to the electrical actuator. Like the above design, this lash adjuster guide block is comprised of a lash adjuster bore extending from one face of the guide block to a location that is at least partially through the guide block. The valve guide is also comprised of a counter bore that extends from the lash adjuster bore to the lash adjuster guide block face opposite that where the lash adjuster bore begins.
At step 250, the lash adjuster guide block is aligned and oriented to the electrical actuator. Fasteners attached to the lash adjuster guide block are aligned with holes located in the bottom of the electrical actuator. The lash adjuster guide block is slipped over the valve actuator return spring. The lash adjuster guide counter bore provides concentricity between the lash adjuster guide block and the electrical actuator. As described above, the tapered valve spring helps to align the lash adjuster guide block to the electrical actuator as the valve guide is slipped over the return spring, and the spring guide acts to further locate the lash adjuster guide block. The guide block is in position when the guide block contacts the electrical actuator. The assembly process then proceeds to step 252.
At step 252, the guide block is attached to the electrical actuator. The guide block may be attached by bolts or other known types of fasteners. In one embodiment, bolts extending from the guide block are used to locate the guide block to the electrical actuator and then tightened to create a valve guide and electrical actuator assembly. Once the guide block is attached to the electric actuator the assembly process goes to step 254.
At step 254, a hydraulic lash adjuster is installed to the lash adjuster guide block. After the guide block and electrical actuator are assembled, the actuator armature stem protrudes into the lash adjuster bore located below the counter bore. The hydraulic lash adjuster is placed in the lash adjuster bore and pushed into the lash adjuster bore until the actuator armature stem is contacted. The lash adjuster may be held in place until final assembly by a light grease or oil. After the lash adjuster is installed the assembly process goes to step 256.
At step 256, the actuator assembly comprising the electrical actuator, the hydraulic lash adjuster, and lash adjuster guide block is oriented to the cylinder head. The actuator assembly may be designed such that it will only mate to the cylinder head when installed in a single orientation. After orienting the actuator assembly, the assembly process goes to step 258.
At step 258, the electric actuator comprising a hydraulic lash adjuster, lash adjuster guide block, and electrical actuator is fastened to the cylinder head. In one embodiment, the actuator assembly is attached to the cylinder head using bolts. However, it is anticipated that other known fasteners may be used to attach the valve actuator assembly to the cylinder head. The assembly process is complete after actuator fasteners are tightened to proper torque and after installation of the electrical connector.
Referring now to FIG. 3 a, an example lash adjuster guide block is shown in position for assembly. Lash adjuster guide block 301 is situated above a cavity designed into cylinder head 310. Valve actuator guide 301 is comprised of fasteners 302 and 303 as well as lash adjuster bore 304 and counter bore 306. Oil gallery 308 provides an oil path from the cylinder head to hydraulic dampener 320 when lash adjuster 320 is installed. In the installed position, oil flows from cylinder head gallery 309 through oil gallery 308 and to lash adjuster bore 304. Poppet valve 307 is held in a closed position by valve spring 305 until the spring force is overcome by force from actuator 301. Arrow A illustrates the direction actuator block 301 is moved during the assembly process described in FIG. 2 a, step 203. Arrow B shows the direction hydraulic lash adjuster 320 moves during installation.
Referring now to FIG. 3 b, an illustration of an installed guide block is shown. Thus, the figure represents a partially installed electrically actuated valve.
The figure shows guide block 301 mated to cylinder head 310. Fasteners 302 and 303 are used to attach guide block 301 to cylinder head 310 and oil galleries 308 and 309 are shown in communication with each other and with hydraulic lash adjuster 320. Poppet valve 307 and valve closing spring 305 remain in the closed position. Hydraulic lash adjuster 320 is shown located in lash adjuster bore 304 to move in an axial direction.
Electrical actuator 350 is shown as an assembly just prior to installation. Actuator 350 is comprised of opening coil 362 and closing coil 360. When current is applied to either coil 360 or 362, actuator armature plate 354 is drawn to the coil through which current flows. Actuator armature plate 354 is attached to actuator armature stem 364. Armature return spring 352 applies a force to drive armature plate 354 and armature stem 364 to the open position. At least some force applied by armature return spring 352 to armature stem 364 can be overcome by applying current to closing coil 360.
Arrow C represents the direction electrical actuator 350 is moved in order to seat the electrical actuator to the cylinder head. When the valve actuator is moved in this direction, the actuator's return spring is inserted into counter bore 306. The counter bore acts to locate and center electrical actuator 350. The diameter of spring guide 356 is designed to be the same as counter bore 306, less 1 mm, in one example embodiment. The spring guide also acts to help locate the electrical actuator to the guide block when the actuator is proximate to the guide block.
Referring now to FIG. 3 c, guide block 301 and electrical actuator 350 are shown installed as part of cylinder head 310. In this embodiment, electrical actuator 350 is bolted to lash adjuster guide block 301, and lash adjuster guide block 301 is shown bolted to cylinder head 310. Electric actuator armature stem 364 is inserted into the tappet body of hydraulic lash adjuster 320. Poppet valve 307 is shown in a closed position. The poppet valve assumes this position when the force provided by valve closing spring 305 is greater than the sum force provided by armature stem 364. When the armature 354 is maintained against the upper core by external forcing, such as from closing coil 360, and the valve 307 is seated by valve closing spring 305, the hydraulic lash adjuster 320 expands to the dimension between the stems. Poppet valve 307 can be opened by supplying current to closing coil 360 such that the sum of forces on the armature stem 364 from the armature 354 and upper spring 352 is greater than the force from the lower spring 305. In some embodiments, the force applied by springs 305 and 352 will be balanced so that the electrically actuated armature 354 is maintains a position at some intermediate position between opening coil 362 and closing coil 360.
Fasteners 302 and 303 are used to attach lash adjuster guide block 301 to cylinder head 310. Likewise, fasteners 370 and 372 are used to attach electrical actuator 350 to lash adjuster guide block 301. In an alternative embodiment, fasteners 370 and 372 can be used to fasten electrical actuator 350 directly to cylinder head 310.
Cylinder head oil gallery 309 is shown in communication with valve guide oil gallery 308 and hydraulic lash adjuster 320 when the electrical actuator is completely installed.
This embodiment of the lash adjuster guide block allows the assembler to install the lash adjuster guide block to the cylinder head with minimal effort. Further, in this design, the guide block can increase the structural strength of the cylinder head. As a result, this lash adjuster guide block design can be used to reduce engine noise while at the same time lowering the cost for cylinder head assembly. Further, this lash adjuster guide block design facilitates the use of low inertia electrical actuators by providing a way to achieve concentricity between armature stem 465 and the stem of valve 453.
Referring now to FIG. 4 a, a schematic of an example alternate guide block and electrical valve actuator is shown. Lash adjuster guide block 402 is designed to be attached to electrical valve actuator 401 using fasteners 430 and 431.
Lash adjuster guide block 402 is shown in cross-section and has oil gallery 425 positioned to feed oil from a cylinder head to a hydraulic lash adjuster. The guide block is also comprised of lash adjuster bore 423 and counter bore 421.
Electrical actuator 401, also shown in cross-section, is comprised of armature plate 411, closing coil 406, opening coil 407, spring guide 413, armature return spring 409, fasteners 441 and 442, and spring retainer 414. The actuator armature is shown in the open position.
The lash adjuster guide block is assembled to the electrical actuator by moving the lash adjuster guide block in the direction of arrow D. In one embodiment, the lash adjuster guide block is oriented to the electrical actuator by uniquely positioning fasteners on the guide block and mounting holes on the electrical actuator such that installation in only a single orientation is possible.
Installation of hydraulic lash adjuster 404 is made in the direction of arrow E after the guide block is installed to the actuator. The diameter of lash adjuster bore 423 is sized the same as the diameter of hydraulic lash adjuster 404, less a predetermined clearance. It should be noted that an annulus may be cut or formed in lash adjuster bore 423 to provide lubricating oil to hydraulic lash adjuster 404. Alternatively, an annulus may be formed in the outer tappet body while lash adjuster bore 423 is smooth.
Referring now to FIG. 4 b, a cross-section of electrical actuator 401 is shown coupled with lash adjuster guide block 402, which houses hydraulic lash adjuster 404 before assembly to cylinder head 460. Electrical actuator 401, lash adjuster guide block 402, and lash adjuster 404, form a valve actuator assembly that can reduce the amount of time necessary to mount a valve actuator to a cylinder head. Actuator return spring 409 provides force to move actuator armature plate 411 to the open position. Coils 406 and 407 are used to reposition armature plate 411 and its attached armature stem 465.
To bring the assembly together, fasteners 430 and 431 attach valve guide 402 to electrical actuator 401. Fasteners 441 and 442 are used to fasten the actuator assembly to the cylinder head and may be positioned such that the actuator assembly can only be attached to the cylinder head one way. Spring retainer 413 is the sized a predetermined amount less than the valve guide counter bore, and it is used along with spring 409 to guide the valve guide into position during the actuator mounting process. When the valve actuator is assembled to the cylinder head, oil gallery 425 is oriented such that oil flows through the lash adjuster guide block and to the hydraulic lash adjuster 404.
Cylinder head oil gallery 450 is shown in a position that enables engine oil to lubricate hydraulic lash adjuster 404. Poppet valve 453 is shown in the closed position in response to force applied by closing spring 451. Spring retainer 452 holds valve closing spring 451 in place. Arrow F designates the direction electrical actuator 401 is moved to mate with cylinder head 460.
Referring now to FIG. 4 c, an assembled view of an electrical actuator attached to a cylinder head is shown. Electrical actuator 401 is attached to cylinder head 460 by way of fasteners 441 and 442. Further, the cylinder head oil gallery 450 is shown in communication with valve guide oil gallery 425 providing oil to hydraulic lash adjuster 404.
The electrical actuator and valve guide assembly is properly seated in the cylinder head by directing the valve guide into the cylinder head receiving port. The stem of valve 453 is put into communication with hydraulic lash adjuster 404, which in turn is in communication with armature stem 465. In some embodiments, installing electrical actuator 401 causes partial compression of armature return spring 409 and valve return spring 451. Partially compressing the springs can leave valve 453 partially open and armature plate 411 substantially centered between armature coil 406 and armature coil 407. Spring 409 provides a force in the direction of the cylinder head through armature stem 465 and hydraulic lash adjuster 404. Conversely, spring 451 provides a force that is in a direction away from cylinder head 460 that acts upon lash adjuster 404. The opposing spring forces act to balance the position of armature plate 411 and valve 453.
One embodiment of the lash adjuster guide block can be installed with the electrical actuator to the cylinder head as a single assembled unit. Therefore, the cost for assembly and replacement of valve actuators can be reduced. And like the previous guide block design, this the lash adjuster guide block design facilitates the use of low inertia electrical actuators by providing a way to achieve concentricity between armature stem 465 and the stem of valve 453.
Referring now to FIG. 5 a, two half cross-sections of a hydraulic lash adjuster having an integral annulus placed in a valve guide lash adjuster bore are shown. The valve guide lash adjuster bore is the area occupied by the hydraulic lash adjuster which includes tappet body 532. Label 306 in FIG. 3 a and label 423 in FIG. 4 a identify the location of a lash adjuster bore in example lash adjuster guide block designs. The lash adjuster is illustrated in two sections to show its range of motion. The half to the left of vertical divider 500 is in the elevated position while the lash adjuster to the right of vertical divider 500 is in a lowered position.
The hydraulic lash adjuster is comprised of pressure chamber 525 and tappet body 532. Pressure chamber moves relative to tappet body 532 to accommodate varying distances between a valve stem and an actuator stem. Tappet body 532 moves up and down in the lash adjuster bore as a valve is opened and closed and has an annulus 535 for distributing oil along the length of the lash adjuster bore. The tappet body is fed oil from gallery 520.
Label 503 identifies the annulus length (La); labels 501 and 507 identify the minimum overlap range (Lo); label 511 identifies the guide length (Lg); label 509 identifies the tappet length (Lt); and label 505 identifies the stroke (Ls). From these references the guide length 511 and tappet length 509 can be determined by the following equations:
Lg=2·Lo+La+Ls
Lt(min)=2·Lo+La
The combination of a smooth lash adjuster bore and a tappet body that includes an annulus produces a short tappet design.
Referring now to FIG. 5 b, like FIG. 5 a, two half cross-sections of a hydraulic lash adjuster having an integral annulus placed in a valve guide lash adjuster bore are shown. The valve guide lash adjuster bore is the area occupied by the hydraulic lash adjuster. Similarly, the lash adjuster is illustrated in two sections to show its range of motion. The half to the left of vertical divider 550 is in the elevated position while the lash adjuster to the right of vertical divider 550 is in a lowered position.
The hydraulic lash adjuster is comprised of pressure chamber 584 and tappet body 570. Pressure chamber 584 moves relative to tappet body 570 to accommodate varying distances between a valve stem and an actuator stem. Tappet body 570 moves up and down in the lash adjuster bore as a valve is opened and closed. The tappet body is fed oil from gallery 580.
Label 553 identifies the annulus length (La); labels 551 and 581 identify the minimum overlap range (Lo); label 561 identifies the guide length (Lg); label 559 identifies the tappet length (Lt); and label 555 identifies the stroke (Ls). From these references the guide length 561 and tappet length 559 can be determined by the following equations:
Lg=2·Lo+La
Lt(min)=2·Lo+La+Ls
The combination of a lash adjuster bore having an annulus and a smooth tappet body produces a short guide block design.
Thus, by strategically picking the location of the annulus different design objectives can be achieved while the lash adjuster is lubricated.
The methods, routines, and configurations disclosed herein are exemplary and should not be considered limiting because numerous variations are possible. For example, the above disclosure may be applied to I3, I4, I5, V6, V8, V10, and V12 engines operating in natural gas, gasoline, diesel, or alternative fuel configurations.
The following claims point out certain combinations regarded as novel and nonobvious. Certain claims may refer to “an” element or “a first” element or equivalent. However, such claims should be understood to include incorporation of one or more elements, neither requiring nor excluding two or more such elements. Other variations or combinations of claims may be claimed through amendment of the present claims or through presentation of new claims in a related application. The subject matter of these claims should be regarded as being included within the subject matter of the present disclosure.

Claims

1. A system for mounting an electrical valve actuator to an internal combustion engine, the system comprising:

an electrical actuator for operating a poppet valve that controls flow to a cylinder of an internal combustion engine;

a cylinder head having at least a poppet valve for directing flow into a cylinder of said internal combustion engine; and

a guide block located between said electrical actuator and said cylinder head, said guide block comprising a lash adjuster bore beginning at a first face of said guide block and ending at a location that is at least partially through said guide block, said lash adjuster bore diameter sized to allow the body of a hydraulic lash adjuster to slide through said lash adjuster bore in an axial direction, said lash adjuster bore aligned with a coaxially situated counter bore that extends from said lash adjuster bore to a second face of said guide block.

2. The system of claim 1 further comprising a hydraulic valve lash adjuster positioned in said lash adjuster bore to move in an axial direction.

3. The system of claim 1 wherein an annulus is formed in said lash adjuster bore of said guide block.

4. The system of claim 1 wherein an oil galley passes through said guide block to supply oil to said hydraulic lash adjuster.

5. The system of claim 1 wherein an armature return spring is located within said counter bore.

6. The system of claim 1 wherein the diameter of said counter bore is substantially that of a spring guide.

7. The system of claim 2 wherein said hydraulic lash adjuster is comprised of a plunger that contacts a stem of said armature, a cup forming a pressure chamber that contacts a stem of said poppet valve, and a tappet body that moves in an axial direction along said lash adjuster bore.

8. A system for mounting an electrical valve actuator to an internal combustion engine, the system comprising:

a guide block located between said electrical actuator and said cylinder head, said guide block comprising a lash adjuster bore beginning at a first face of said guide block and ending at a location that is at least partially through said guide block, said lash adjuster bore diameter sized to allow the body of a hydraulic lash adjuster to slide through said lash adjuster bore in an axial direction, said lash adjuster bore aligned with a coaxially situated counter bore that extends from said lash adjuster bore to a second face of said guide block, said guide block fastened to said electrical actuator.

9. The system of claim 8 further comprising fastening said electrical actuator to a cylinder head.

10. The system of claim 8 further comprising a hydraulic valve lash adjuster positioned in said lash adjuster bore to move in an axial direction.

11. The system of claim 8 wherein an annulus is formed in said lash adjuster bore of said guide block.

12. The system of claim 8 wherein an oil gallery passes through said guide block to supply oil to said hydraulic lash adjuster.

13. The system of claim 8 wherein an armature return spring is located within said counter bore.

14. The system of claim 8 wherein the diameter of said counter bore is substantially that of a spring guide.

15. The system of claim 10 wherein said hydraulic lash adjuster is comprised of a plunger that contacts a stem of said armature, a cup forming a pressure chamber that contacts a stem of said poppet valve, and a tappet body that moves in an axial direction along said lash adjuster bore.

16. A method for assembling an electrical valve actuator to an internal combustion engine, the method comprising:

attaching a guide block to a cylinder head of an internal combustion engine by aligning oil galleries of said cylinder head and of said guide block, said guide block comprised of a lash adjuster bore extending partially through said guide block, said guide block further comprised of counter bore extending from said lash adjuster bore to the extent of said guide block;

inserting a hydraulic lash adjuster through said counter bore and into said lash adjuster bore; and

fastening an electrical actuator having an armature return spring to said cylinder head by inserting said return spring into said counter bore and fastening said electrical actuator to said cylinder head or said guide block.

17. The method of claim 17 wherein said oil galleries provide oil to said hydraulic lash adjuster.

18. The method of claim 17 wherein said lash adjuster bore includes an annulus.

19. The method of claim 17 wherein said guide block is fastened to said cylinder head before said electrical valve actuator is fastened to said cylinder head or said guide block.

20. The method of claim 17 wherein said guide block counter bore is used to locate said electrical actuator to said cylinder head.

21. A method for assembling an electrical valve actuator to an internal combustion engine, the method comprising:

producing an assembly by attaching a guide block to an electrical actuator, said guide block comprised of an oil gallery, a lash adjuster bore for housing a hydraulic lash adjuster, and a counter bore for housing an actuator return spring;

inserting said assembly into a cylinder head and aligning said oil gallery to an oil gallery located in said cylinder head; and

fastening said electrical actuator to said cylinder head.

22. The method of claim 22 wherein said electrical actuator is fastened to said cylinder head by fasteners that extend at least partially through said electrical actuator.

23. The method of claim 22 wherein said guide block is used to locate said electrical actuator to said cylinder head by fitting said guide block into said cylinder head before said electrical actuator contacts said cylinder head.

24. The method of claim 17 wherein said lash adjuster bore includes an annulus.