JPH06200721A - Internal combustion engine - Google Patents

Abstract

PURPOSE: To provide an independent supply source of pressurized oil in a hydraulic tappet of an internal combustion engine. CONSTITUTION: Pressurized oil is supplied from an oil pressure source having a pressure higher than normally forecasted pressure, which is independent of a hydraulic tappet 18. The oil pressure source uses the lubricant oil from an oil sump 16 or a crankcase. The oil delivered to a lifter galley is directed from a known necessary oil pump or a separate oil pump 12 for a valve galley. The pressure of the pump is set to the high pressure for engine speed i.e., the pump speed or high engine speed in the case of an electric operated separate pump. The desired oil pressure level delivered to the valve galley controls the pump speed in the case of an electric pump and controls the bypass flow rate in the case of a mechanical pump based on the signal of a computer 20 monitoring the manifold pressure, the engine speed and the throttle position. A second auxiliary valve for galley delivery is provided so that the electric pump delivers oil from the auxiliary valve to an engine region requiring lubrication when the normal pump is broken-down.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to internal combustion engines, and more particularly to internal combustion engines which utilize hydraulic tappets for tappet actuation which require an oil source to be delivered under pressure. . Hydraulic tappets are known in the art and will not be described in detail here.

[0002]

2. Description of the Related Art Hydraulic tappets (hydraulic v)
In the current state of the art of engines using alv lifters, pressurized oil is supplied to the tappet from an engine oil pump. For new engines and engines with new oil, this means of supplying oil to the hydraulic tappet is almost satisfactory for average engine operation. However, when the oil becomes old, or becomes extremely hot, or the engine wears, the normal hydraulic pressure supplied by the conventional engine oil pump drops. This pressure drop reduces the oil flow and the pressure of that oil delivered to the tappet, causing the tappet to move slightly at a particular engine RPM, and / or the tappet's plunger coming into loose contact with the valve stem. A change in the valve timing that is normally expected occurs at the speed of.

Generally, the function of hydraulic tappets is to maintain physical contact between the valve drive links, ie, the cam lobe and the valve stem or rocker end, to reduce mechanical noise of valve actuation and Continuous adjustment of gear and valve link wear. In order to achieve ideal operation at different RPMs, a slight adjustment of valve stem length is needed to slightly change valve timing and head, but to resolve inaccurate valve timing at different RPMs. However, no consideration is given to changing tappet operation or intentionally.

Other methods of variable valve timing include lead and lag systems, multi-contour cams, solenoid / helenoid actuated valves, and high leak hydraulic tappets.

The present invention is an engine part.
and long-term requirements for a tappet system to compensate for the low hydraulic pressure transmitted to the tappet and to control the degree of valve lift by the tappet during valve opening and closing at various engine speeds.

Meets the requirements

SUMMARY OF THE INVENTION It is an object of the present invention to provide a hydraulic tappet such as an internal combustion engine with an independent source of pressurized oil.

Another object of the present invention is to provide independent oil supply to a hydraulic tappet of an internal combustion engine, the pressure of the oil being in a wide range regardless of the oil pressure of the internal combustion engine used for conventional engine lubrication. Can be selected from various pressures.

Another object of the present invention is to provide an oil source to a hydraulic tappet of an internal combustion engine, the pressure of the oil source being independent of the internal combustion engine RPM.

Still another object of the present invention is to provide a hydraulic tappet with means for effectively changing the degree of lift of the valve by changing the hydraulic pressure.

Yet another object of the present invention is to provide a hydraulic tappet for an internal combustion engine to vary the lift and / or duration of operation provided to the valve under certain selected engine RPM conditions. The purpose is to selectively increase or decrease the hydraulic pressure.

Yet another object of the present invention is to provide a normal engine, when using an independent hydraulic tappet hydraulic supply.
To provide a secondary source of engine lubricating oil in the event of an oil pump failure.

[0012]

SUMMARY OF THE INVENTION The present invention is directed to engine lubrication oil pressure, engine oil conditions, or engine RPM.
Independent of (revolution), it is directed to an independent pressurized engine oil supply so that it always supplies a selected level of hydraulic pressure to the hydraulic tappet.

Generally, the oil lines and passages are the outputs of conventional engine oil pumps.
From the side to the block or head where the hydraulic tappet is placed. The oil that drains from the hydraulic tappet during operation is returned to the engine sump or crankcase. In the first embodiment of the present invention, a conventional engine oil pump having a pressure higher than the normal expected oil output pressure is used. The pump output is bifurcated and a portion of the oil output is delivered to the normal region requiring progressive lubrication, as in conventional engines, and
The remaining part is a hydraulic lifter galley.
lley). The regulated pressure relief valve prevents excess hydraulic pressure levels from entering the traditional engine forward lubrication region. A computer with a sensor and bypass valve regulates the hydraulic pressure flowing to the hydraulic lifter galley. The galley pressure increases when greater valve lift is required at any position in the valve lift curve, and decreases when smaller valve lift is required. Additional sensors measure engine RPM, manifold pressure, throttle position.

In the first embodiment, the conventional engine
Hydraulic lifter galley supply channel from the oil pump is separated or recombined from the output of a conventional engine lubricating oil pump and is also a continuous supply from the engine sump or crankcase. Is connected to and supplied with engine oil by a separate oil pump. A separate oil pump can be operated electrically or mechanically. The desired pressure is maintained at a desired hydraulic pressure from a constant speed pump, either by controlling the RPM with an electric pump or by releasing excess pressure from or before transfer to the sump. Maintained. When a mechanical pump is used for the lifter galley supply, it meshes with the engine speed and produces higher pressure than required even at low engine RPM. This maintains the desired pressure as previously described by bypassing a selected amount of pressurized oil in the sump, but such bypass is necessary to maintain the desired galley pressure. By using an oil pump system or the like, an onboard controller or computer is used to monitor the engine RPM and control the pump output hydraulic pressure to the tappet.

The system of the present invention can increase the hydraulic pressure of the liquid tappet to a pressure high enough to increase or decrease the valve lift that would normally be expected for the hydraulic tappet at any position along the cam lift curve. Resulting in the selected timing and duration of. This feature is very important when extremely low or high engine RPM is required, i.e. during city and highway driving. For example, at high pressure, the lifter valve actuating plunger is varied by a thousandths of an inch to produce the desired ideal valve opening time for high RPM. This has the effect of extending the valve stem. Alternatively, reduce the pressure for low RPM so that the plunger simply contacts the valve actuation rod at the lowest pressure, reducing the valve actuation length by approximately one-thousandths of an inch, which allows it to move under the cam lift curve. Increase valve opening time and area.

In the first embodiment, an electrical valve is provided to provide normal engine lubrication in the event of engine oil pump failure. When ground contact is detected, either by lack of hydraulic pressure or from registration of zero oil pressure from a hydraulic gauge, the valve operates by receiving a signal from an oil pressure sensor, which is usually in the vehicle.

In the present invention in the second embodiment, a conventional engine oil pump is used and has a pressure higher than the normally expected oil output pressure. The pump power is bifurcated, with half of the oil power being delivered to the normal region requiring progressive lubrication, as in conventional engines, and the other half to the hydraulic lifter galley. A regulated pressure relief valve prevents excess hydraulic pressure levels from entering the traditional engine forward lubrication region. As in the first embodiment, a computer with a sensor regulates the pressure of oil flowing to the hydraulic lifter galley of all or individual valve lifter galleys. When a larger valve lift is required, the galley pressure increases and also
Galley pressure is reduced when a smaller valve lift is required.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, and particularly to FIG. 1, there is shown a schematic of a first embodiment of a hydraulic tappet system 10. The oil pump 12 is an electrical type that operates from the vehicle electrical system. Oil pump 12 is a low engine RP
It may be a mechanical pump that is coordinated with the mechanical rotation of the engine associated with the pump 12 to provide a high level of hydraulic pressure under M. Mechanical or constant speed electric pumps are provided with a bypass oil outflow system having a bypass return line 14 extending to a sump 16. The sump 16 regulates the actual selected pressure supplied to each hydraulic tappet 18 or common galley separately through the pump output line 17. The outflow system for these pumps has pressure bypass means (not shown) regulated by the controller or computer 20 at the position of each valve or common galley. The controller or computer 20 may check the manifold pressure and slot position from suitable sensing devices as well as the conventional RPM sensor 22 to engine RPM known in the art.
Receive information input. For variable speed electric pumps, the motor speed can be varied to provide the exact pressure required.

A detailed cross-section showing a typical prior art tappet 18 is shown in FIG. Any equivalent hydraulic tappet 18
Can be used to carry out the present invention.

A pump of the type described herein or any other equivalent pump is controlled by an onboard computer 20 which is controlled by an RPM derived from an engine RPM sensor 22 or driver input. The onboard computer may be a typical computer called an electronic control module (ECM). It is found in modern automobiles, monitoring engine RPM, controlling electric engine timing, controlling smog, and other functions modernly required for internal combustion engines. An example of such a computer is
It is manufactured by General Motors, Ford Motors, Chrysler, etc., which are widely used in modern automobile models.

The pump 12 has an oil supply or input line 24 located below the normal oil level 26 of the engine sump 16, and a bypass or return oil line 14 is convenient for draining from the pump to the sump. It extends to a certain position. The output oil line 17 of the pump 12 is connected to a hydraulic tappet supply line 28 called a lift galley which is cast in a head or block 29,
Here, the tappet is placed in close proximity to the head or block 29 with a small feed hole between the feed line or galley 28 and the internal mechanism of the tappet described below with reference to FIG.

In FIG. 3, a detailed cross section of a typical hydraulic tappet is shown. Prior to illustration, the principle of the zero-lash type hydraulic tappet 18 will be described. The tappet is made up of a cylinder B, a plunger E, a ball check valve G and a light spring F. The oil from the pump 12 passes through the line 28, and the tappet (lifter) directly above A.
It is supplied to the supply chamber J in the lifter body through the guide. In this case, it feeds into the pipe K and through the check valve G into the space H between the bottom of the cylinder B and the plunger E. While in the closed position of the valve, ie tappet 1
When the 8 is on the circular or unlifted portion 30 of the cam 32, the spring F begins to raise the plunger E into contact with the valve stem or rocker arm 34. Cam 3
When 0 begins to raise the tappet (see valve opening duration curve in FIG. 4), pressure is increased in the space H, pushing the valve G against its seat L. Further cam lift on the tappet increases the pressure in the compression chamber H so that the entire assembly acts as a solid member to raise the associated engine valve from its seat. The initial bubbles in the oil in the compression chamber H leak through the gap I between the plunger and the cylinder. Compensation for wear on the rising surface of the tappet or valve stem, or tappet end, is provided by allowing a slight oil leak under load between the plunger and cylinder.

In the present invention, for example, the equivalent plunger E is somewhat larger in length, changing in the cylinder by at least fifty thousandths of an inch, and also has the least amount of change at the beginning of the sustain curve of FIG. May have a greater distance under constant engine predictive operating RPM, ie for extremely high RPM engines. The hydraulic tappet and support system of the present invention operates as follows.

During the low RPM lift duration, a low oil pressure is created so that the compression chamber H is under a low oil pressure, and
The plunger is required to move a considerable distance by the action of the cam along the continuation curve before the engine valve lifts from its seat. On the other hand, if a high lift duration is required, then pressure is increased from pump 12 and compression chamber H is at a higher pressure, which causes the engine valve to move away from the seat more quickly, So much higher at any position in the sustain curve than the low lift example valve. The amount of pressure required in the compression chamber H is determined by the timing required to open the engine valve for the most effective engine operation. The present invention further compensates for low normal engine generated hydraulic pressure due to wear and the like which gradually reduces engine efficiency over the life of the engine.

The hydraulic tappet oil supply pressure is controlled by a computer controlled pressure relief valve 29, as shown in FIG.
A similar control is provided when located at the end of an individual gallery in each lifter gallery away from the hydraulic valve oil common gallery or oil input end. Figure 5 shows the supply of lubricating oil required for engine operation.
1 schematically illustrates an auxiliary source of pressurized lubricating oil for engine lubrication in the event of a pump failure. The auxiliary oil pump 12 can supply a fixed amount of lubricating oil to the moving parts of the engine for at least sufficient time to prevent the engine from overheating or freezing. A normally closed electrical valve 34 is placed between the pump 12 and the lifter block or head supply line 28. The electric valve 34 requires an earth in the electric wire 35 so as to change the electric valve 34 to the open state. When the hydraulic light 39 on the vehicle dashboard is illuminated by low or no engine oil pressure, there is a ground condition for the wire 35 and the valve 34 is open to bring normal pump 12 oil pressure to the oil line 37. Shed on. oil·
The line is an engine that supplies main rods, cam bearings, etc.
It extends to an oil lubrication system.

FIG. 6 shows the outline of the second embodiment. In this embodiment, the oil pump 42, which has a hydraulic volume output in excess of the normally desired engine oil pressure, replaces a conventional oil pump in a given engine. The pump output is split into two separate output lines 44,46. Line 44 inputs pressure regulator valve 48, and the output pressure level to line 17 is controlled by computer 20 and sensor 22 as previously described. Line 46 is a pressure regulator 50 well known in the fluid regulation art that prevents normal engine lubrication pressure from exceeding its required pressure.
Enter.

[0027]

The present invention provides a valve lift system that compensates for the need to control the valve lift through the tappet during periods in which the valve opens and closes at engine parts, synthetic low oil pressure delivered to the tappet, and different engine RPMs. Meets what has been long required of.

The variable timing system of the present invention is made at low cost, is easily adaptable to existing engines,
The exhaust valves can be controlled independently, are reliable to operate as expected, give a great improvement in fuel economy, reduce undesired energy dissipation, give better engine idle, more useful from a given engine Powered and gives a better start.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a first embodiment of an internal combustion engine of the present invention.

FIG. 2 is a schematic configuration diagram of a second embodiment of an internal combustion engine of the present invention.

FIG. 3 is a detailed view of a typical conventional mechanical cam actuated hydraulic tappet used to practice the present invention.

FIG. 4 shows an opening / closing operation curve of a valve.

FIG. 5 is a schematic diagram of an emergency engine auxiliary lubricating oil source.

FIG. 6 is a schematic configuration diagram of a second embodiment of the internal combustion engine of the present invention.

[Explanation of symbols]

 10 Hydraulic Lifter System 12 Oil Pump 14 Bypass Return Line 16 Sump 18 Hydraulic Tappet 17 Pump Output Line 20 Computer 22 RPM Sensor 24 Input Line 26 Normal Oil Level 28 Supply Line 29 Head 30 Circular Section 32 Cam 34 Valve system 35 Electric line 37 Oil line 42 Oil pump 44,46 Output line 48 Pressure regulating valve

Claims (11)

[Claims] 1. An internal combustion engine having a hydraulic tappet including a source of pressurized oil for operating the hydraulic tappet and means for selectively controlling the pressure of the pressurized oil during operation of the hydraulic tappet. 2. The internal combustion engine according to claim 1, wherein the engine includes an engine oil pump, and the pressurized oil source is supplied from an auxiliary oil pump. 3. The internal combustion engine according to claim 2, wherein the auxiliary oil pump is provided with control means for changing the output oil pressure independently of the engine speed. 4. The internal combustion engine according to claim 1, wherein the controlled pressure of oil supplied to the hydraulic tappet is controlled by a computer. 5. A switching means for supplying pressurized oil from the auxiliary pump to the engine for lubrication when the engine oil pump cannot supply lubricating oil. Internal combustion engine described. 6. The internal combustion engine of claim 1, wherein the source of pressurized oil is generated higher than a conventional engine oil pump of normal output. 7. A galley means having an input end for supplying oil to the tappet under pressure and an output end for returning the oil to a pressurized oil source, wherein the means for controlling the pressure of the pressurized oil is the galley. The internal combustion engine according to claim 1, wherein the internal combustion engine is provided at the output end of the means. 8. The lift of the hydraulic tappet when the valve is opened,
2. The internal combustion engine according to claim 1, wherein the height of the head is selectively and unlimitedly changed by selectively controlling the pressure of the high-pressure oil delivered to the tappet. 9. The lift of the hydraulic tappet can be selectively and unlimitedly varied in duration by selectively controlling the pressure of high-pressure oil delivered to the tappet when the valve is opened. The internal combustion engine according to claim 1. 10. The internal combustion engine of claim 7, wherein the galley means includes a common galley for the plurality of hydraulic tappets. 11. The internal combustion engine of claim 7, wherein the galley means includes a separate galley for each of the plurality of hydraulic tappets.