JPS63179113A - Lubrication system and pump for internal combustion engine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a lubrication system for supplying lubricating oil to internal combustion engines, particularly two-stroke cycle engines, and to a lubrication pump for that purpose.

(Problems with the Prior Art) The lubrication system of an internal combustion engine has the primary function of distributing the appropriate amount of oil to the many moving surfaces of the engine, and has many lubrication systems widely known in the engine industry. For a reason, air and other gases are entrained in the oil, and the pump must therefore be able to operate effectively under these conditions. When the engine is not running for long periods of time, oil escapes from the many ducts and passageways of the lubrication system. Under these circumstances, it is necessary that the pump first be able to evacuate air from the system before beginning to evacuate oil.

A recent trend in engines operating on a two-stroke cycle, such as is common in outboard engines, is that oil and fuel mix in the engine's lubrication system, causing inconvenience and thereby pollution problems. The goal is to avoid this from happening.

Such engines typically include pump(s) to supply a quantity of oil to the many areas of the engine that need to be lubricated. A control system is used on the pump to vary the amount of oil delivered in response to the lubricating oil needs of specific areas of the engine, which are essentially related to both engine speed and engine load.

Pumps for this purpose can be used, for example, by driving the pump continuously at a speed proportional to the engine speed and by varying the amount of pump travel per stroke depending on the air throttle position of the engine, i.e. the engine load. controlled. These systems have a limited degree of control over the oil supply rate, and are therefore costly both in terms of fabrication and assembly, and suffer from mechanical wear and a high rate of loss in accuracy of oil supply control. It has the disadvantage of requiring a complex mechanical structure.

Additionally, the pumps currently used to lubricate two-stroke cycle engines are not easily electronically controlled. This is difficult because it requires many mechanical structures that interfere with electronic control.

It is therefore a principal object of the present invention to provide a lubrication system and pump for the controlled delivery of oil to internal combustion engines, particularly engines of the two-stroke cycle.

(Means for Solving the Problems) From the viewpoint of this object, the lubrication system for an internal combustion engine according to the present invention includes a pump device that has a constant oil distribution amount for each cycle and supplies oil to a predetermined position of the engine. a motorized device operable to produce periodic motion and coupled to drive the pumping device with pump cycles that are a constant ratio to the cycles of the motorized device; a device for determining the required amount of oil at its predetermined location; and a device operable in response to the predetermined amount of oil to control the number of cycles of the motorized device and to be supplied at a given time by the pumping device. an apparatus for associating a quantity with said scheduled oil requirement;
It is equipped with

The electric device is conveniently a solenoid device connected to the pump device to cause the pump device to perform one cycle every cycle. The pump device is a piston type pump directly connected to the armature of the solenoid device. The solenoid device is arranged to drive two or more pump devices simultaneously, periodically, or in a combination thereof. For convenience, two pumps are connected to the armature of one solenoid device, one at each end. These pumps are preferably half a cycle offset from each other, so that as one pump dispenses oil, the other draws in oil.

The amount of oil can be precisely controlled by controlling the cycle of the solenoid. The required amount of oil can be easily determined by a suitably programmed electronic control unit (E, CU). The ECU receives signals related to parameters of scheduled engine operation and uses its input to determine the required frequency of the solenoids and other electrically powered devices to meet the oil requirements of the engine. Among the engine operating parameters used in determining oil requirements are engine speed, engine temperature, amount of air introduced, engine fuel consumption, and the amount of time the engine operates within the intended load and/or speed range. Contains.

Engine lubrication systems typically require oil to be supplied to more than one location, and the oil requirements at each location are different. If the difference in the amount of oil required at each position (if the relationship is almost fixed for all operating conditions), a separate pump is provided at each position, and all pumps are driven by the same electric device, and each pump Each pump has a dispensing amount for each pump cycle.

In a multi-cylinder engine, several pumps may be provided, each pump arranged to supply oil to the same location for all cylinders. Thus, one set of pumps, driven by the same electric unit, supplies oil to the crankcases of several cylinders, and another set of pumps, all driven by a second electric unit, supply oil to several cylinders. supply to the pistons of several cylinders.

Accordingly, another aspect of the invention provides an oil pump for incorporation into an engine lubrication system, the pump having a cylinder closed at one end, a valve-controlled outlet at the closed end, and a cylinder having a closed end. a piston movable axially within the cylinder and defining a working chamber between the piston and the closed end; and a drive for periodically reciprocating the piston within the cylinder; The working chamber changes volume in response to the axial movement, and the piston is in a face-to-face relationship with a skirt portion slidably received in a substantially sealing manner within the cylinder and a closed end of the cylinder. a head portion supported for a range of axial movement relative to the skirt portion, the head portion and the skirt portion being responsive to the range of axial movement; selective communication between said working chamber and a feed section of the cylinder opposite said head section, so that oil can flow from the head section into the working chamber when the piston leaves the closed end of the cylinder and when said piston moves away from the closed end of the cylinder; When moving in the direction, the flow of oil between the working chamber and the supply part of the cylinder is prevented.

This pump is preferably integrated as a positive displacement pump into the aforementioned lubrication system, and the two pumps are connected to one drive, such as the aforementioned electric drive.

Conveniently, a range of axial movement between the head and skirt portions of the piston periodically opens and closes the annular passage therebetween to control the flow of oil into the working chamber. Preferably, the outlet incorporates a pressure-sensitive valve device so that oil can be supplied when the pressure in the working chamber exceeds a predetermined value.

The head portion of the piston conveniently has a diameter so as to provide an axial annular passage between the periphery of the head portion and the wall of the cylinder to provide a portion of the flow path for oil to the working chamber.

Axial movement of the head portion away from the skirt portion provides an annular passageway between the head portion and the skirt portion for communicating the axial annular passageway with a hollow interior of the skirt portion. The piston head portion and the skirt portion, when axially separated, form opposing walls of a radial annular passage and periodically sealingly abut the piston head portion and the skirt portion to facilitate the flow of oil from the head portion into the working chamber. Each has an annular surface that prevents.

The head part is preferably connected to the skirt part so as to provide a constant axial movement each time the direction of axial movement of the piston changes. That is, when the piston is moving towards the closed end of the cylinder,
The respective radial surfaces of the skirt portion and head portion abut sealingly. When the skirt section changes its direction of movement away from the closed end of the cylinder, the skirt section first moves a short distance before the head section moves in the opposite direction, thereby separating the two annular surfaces and pulling them together. Create a radial annular passage between them.

Oil enters the working chamber through a radial annular passage and an axial annular passage. When the piston changes direction of movement within the cylinder at the opposite end of its axial movement, an opposite relative movement occurs between the skirt portion and the head portion to close said radial annular passage.

The invention will become more readily apparent from the following description of a preferred embodiment of an engine lubrication system and its pump, illustrated in the accompanying drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1 and 2, a pump device includes a cylindrical housing 1 having a cylindrical core 2 around which a coil winding 3 is wound.

An armature 4 is arranged in the central cavity of said cylindrical core 2, and a compression spring 5 is interposed between the armature 4 and the inner shoulder 6 of the core 2.

A spring 5 presses the armature upward in FIG.

The annular end 7 of the housing 1 is made of magnetic material and is provided with an inner cylindrical surface 8 forming a narrow annular gap 9 between the cylindrical surface 8 and the cylindrical end 10 of the armature 4. The winding 3 is wound so that the magnetic field generated when energized can pull the armature 4 downward in FIG. 1 against the force of the spring 5. Thus, when the winding 3 is deenergized, the spring 5 returns the armature upwardly to the position shown.

A cylindrical tube 11 made of non-magnetic material extends concentrically within the armature 4 and is fixed therein. At each end of the armature 4 a tube 11 extends in the axial direction so that the tube 1
1, each piston skirt 12.13 is slidably accommodated in each cylinder 14.15. said piston skirt 12.13 is free to slide within the cylinder 14.15 and cooperates therewith in an almost sealing manner;
It is as if the piston operates inside the cylinder in a normal reciprocating pump.

Each piston scar) 12.13 abuts with its free end a respective piston head 16.17, which piston heads each have a one-piece guide 18, 19 slidably received at each end of the bore of the tube 11. have The armature 4
Bins 20.degree., 21, which are fixed in place, pass through the six holes 22.23 and the guides 18.19, with a predetermined gap in the axial direction of the drive 11 between the bottles and the holes through which they pass. The presence of this gap allows each piston head 16.17 to carry out a constant axial movement relative to its mating piston skirt 12.13.

Each cylinder 14.15 is closed by a respective end wall 24, 25 with an outlet 26.27. ``The outlets are normally closed by respective ball valves 28, 29, which are kept in the closed position by springs 30, 31.

As shown in the drawing, the armature 4 is at the limit of its upward movement and in this position the working chamber 35, which is provided between the piston head 17 and the end wall 25 of the cylinder 15, has its maximum volume. The working chambers 36 at both ends of the valve arrangement between the piston head 16 and the end wall 24 have a minimum volume when the armature moves to the opposite end of its range of travel.
has a minimum volume and the working chamber 36 has a maximum volume.

Equipped with a nipple 37 for connection to an oil pipe leading to an oil tank,
Oil normally fills all free space within the housing 1, including the interior of the tube 11 and the interior of the piston skirt 12,13. A series of holes 40.41 are provided in the walls of tube 11, piston skirt 12.13 and piston head guide 18.19, as shown, for admitting oil into the interior thereof.

For example, consider in detail the operation of one of the piston skirt and piston head assemblies made of piston skirt 13 and piston head 17 at the lower end of FIG. Assuming that the working chamber 35 is filled with oil in the position shown, the armature 4 begins to descend in FIG. 1 when the coil 2 is energized. This movement is directly caused by the tube 11 and the pin 21.
The oil in the chamber 35 is thus pressurized.

When the oil pressure becomes high enough to move the ball valve 29 against the force of the spring 31, the oil is forced to flow out of the port 27. The movement of the armature 4 is limited by its contact with the end wall 25 of the piston head 17, in which position all oil is forced out of the working chamber 35.

When the coil 3 is deenergized, the spring 5 moves the armature to the first position.
In the figure it begins to rise and this movement is immediately transmitted to the tube 11 and piston skirt 13. However, since there is a gap between the pin 21 and the hole 23 of the piston guide 19, there is no immediate corresponding movement of the rad 17 towards the piston. In this way, 'the piston head 17 does not move and the contact between the radial surface 42 of the piston head and the corresponding radial surface 43 of the piston skirt is broken;
An annular radial passageway 44 is thus formed as shown in FIG. As the armature 4 continues to rise, the gap between the pin 21 and the hole 23 disappears, and then the piston head 1
7 moves together with the piston skirt 13. However, an annular radial passage 44 remains between them;
Therefore, the piston passes from the inside of the piston skirt 13 around the piston head 17 and enters the working chamber 35.

When the upper limit of the armature 4 is reached, the piston rad 17 is still separated from the skirt 13 and forms an annular passage 44.

When the next cycle begins, the energization of the coil 3 again begins to lower the armature 4 as shown in FIG. 1, and at this time the tube 11 and piston skirt 13 immediately begin to descend. Since there is a gap between the pin 21 and the bore 23, the piston head 17 immediately descends in the same manner and so that the end face 42 of the piston skirt 13 is aligned with the radial face 43 of the head 17.
, until there is contact between them, after which the piston head and piston skirt move together toward the cylinder end face 25, thus beginning another oil draining cycle.

The piston head 16 and piston skirt 12 at the opposite ends of FIG. 1 operate in the same manner as the piston head 17 and piston skirt 13, but are half a cycle out of phase.

In the above configuration, it is necessary to do the following.

That is, there is sufficient clearance between the peripheral edge 45 of the piston head 17 and the wall of the cylinder 15 so that the annular gap around the piston head 17 allows oil to pass into the working chamber during the suction stroke. It needs to be sufficiently wide. However, this gap must also be kept low enough so that when the piston head 17 reaches the end of its stroke toward the end wall 25, the gap volume in the working chamber 35 does not substantially affect pump operating efficiency. No.

This is particularly important for the following reasons. This means that the pump has to expel air or a mixture of air and oil from the environment, and therefore the air remaining in the working chamber must be kept to a minimum if the clearance volume is kept to a minimum. This is because the pumping action normally obtained by the movement of the piston can be nullified. The diameter of the piston head 16, 17 is preferably the same as that of the cylinder 15 in which this piston operates.
0.75 or less of the inner diameter of

To reduce the binding effect between the piston head and the end wall of the cylinder, one or more transverse grooves are provided in the surface of the piston head opposite one end wall of the cylinder, the groove extending from the peripheral edge of the piston head. It is extending. Alternatively, the surface of the piston head may be formed to reduce the area of contact with the end wall of the cylinder.

In order to improve the volumetric efficiency of the above-described pump, a resilient device, such as a spring, may also be provided on the radial surface 42.
．． The piston head can be arranged such that 43 contacts and closes the annular radial passage 44. This configuration has the following effects. That is, at the end of the movement of the piston skirt 13 in the direction away from the end wall 25, the piston rad 17 continues to move in that direction by means of a resilient device, with the effect of closing the passage 44 before or when the direction of movement of the piston skirt changes. has. Therefore, the piston skirt 13 while the passage 44 is open
The proportion of the cylinder's approach to one end wall 25 of the cylinder is eliminated or reduced, thus increasing the volumetric efficiency of each cycle.

The resilient devices or springs described above with respect to the piston skirt 13 and head section 17 are also operatively provided on the piston skirt 12 and head section 16 at the opposite end of the pump arrangement. In the preferred embodiment, a tension spring is connected between the piston head portions 16, 17 and expanded to effect the operation described above.

FIG. 3 shows a typical lubricating system for a two-cylinder, two-stroke engine equipped with the oil pump described above.

The engine 100 is of conventional construction, with each cylinder 10
3.Individual crankcase area 10”l cooperating with 104
, 102, air is introduced. Air flow to each crankcase is through an air inlet duct 105 in which a conventional throttle valve 106 is arranged and which duct has a respective reed valve arrangement 107, 108 communicating it to the respective crankcase. We are prepared.

An air flow sensor device 110 of known construction is integrated into the air inlet duct, which sensor device supplies a signal to an electronic control unit (ECU) that is proportional to the air flow rate to each crankcase. The air flow rate in the air introduction duct is proportional to the engine load, so the input from the air flow sensor 110 to the ECU provides the ECU with a measurement of the engine load.

An engine speed sensor 112 of known construction is arranged to be operated on the flywheel 114 of the engine to provide a signal indicative of engine speed to the ECU.

The ECU is programmed to determine the engine's lubricating oil requirements from the airflow sensor and speed sensor inputs, and the ECU controls the period of the oil pump 120 energization cycle in accordance with this determination. As previously mentioned, the oil pump supplies two fixed amounts of oil for each cycle. Each oil supplied is connected to a reed valve device 107゜1 which controls the airflow entering each crankcase.
08 is routed through ducts 121, 122 into the air introduction duct 105 at each location. The supply of oil is carried out through suitable nozzles 12B, 124, and the oil becomes a fine spray when it exits into the air, and each nozzle is equipped with a check valve and is connected from the air introduction duct to the ducts 121, 122.
Prevent air from entering.

In the illustrated embodiment, ECU 115 is programmed to control the metering and delivery of fuel into each cylinder of the engine through injector 130 as well as metering device 131. The ECU may be programmed to control other operations of the engine, such as ignition timing, and inputs regarding other engine operating parameters and conditions may be provided to the ECU for this purpose. When the engine is equipped with a device that changes the opening and closing timing of the exhaust port, this is also controlled by the same ECU.

In the lubrication system described with reference to Figure 3, the lubrication of the crankcase bearings and the pistons in the cylinders is achieved by entraining oil into the air introduced into the engine crankcase and then into the engine cylinders. It is done by doing. This involves pre-mixing the fuel with lubricating oil (not similar to traditional methods).

However, in the embodiment shown in FIG. 4, fuel is not introduced into the air entering the engine, but is pumped directly to the bearings and engine cylinders at any location to lubricate them.

In the configuration shown in FIG. 4, oil pump 140 has the same construction as previously described and supplies two fixed amounts of oil per pump cycle. In this configuration, the pump supplies oil to the bearing 141 and cylinder duct 142. Bearing oil requirements and cylinder/piston oil requirements are different and therefore different amounts are used. The different amounts are achieved by discharging different constant amounts of oil from the working chamber 35, 36 and preferably by varying the diameter of the piston 16, 17. Bearing duct 1
41 distributes oil to appropriate locations within the crankcase, ie locations where oil is effectively supplied to the crankshaft bearings. The oil is supplied in the form of a spray, which is suitably arranged to lubricate the associated bearings in the crankcase area. A cylinder duct 142 supplies oil through holes in the cylinder wall to locations selected to effectively lubricate the piston-to-cylinder contact surfaces as well as the contact surfaces of the rings attached to the piston.

The ECU115A used in the lubrication system shown in Figure 4 is the third
It may receive signals from an airflow sensor 144 provided in an air intake passageway 145 of the engine, and may also receive signals from a suitably located engine speed sensor (not shown). .

In the lubrication system described in connection with FIG. 3, one oil supply is required for each cylinder of the engine, so that the above unit with two oil supplies per cycle supplies lubricant to two cylinders of the engine. suitable for supplying. However, the configuration shown in Figure 4 requires two oil supplies to each cylinder of the engine, one to lubricate the bearing surface of the engine crankshaft and another to lubricate the piston. Therefore, one oil pump with two supplies per cycle is required for each cylinder of the engine.

In a multi-cylinder engine using the system of FIG. 4, one pump is used to supply oil to the crankshaft bearings of all cylinders of the engine;
And another pump is used to supply oil inside all the cylinders of the engine.

FIG. 5 is a representative somewhat simplified diagram of the logic provided in determining the operating period of the oil pump unit from engine condition parameters supplied to the ECU. The ECU accepts the aforementioned series of inputs, including measurements of airflow velocity to the engine air induction system, engine speed, engine temperature, and other parameters relating to engine operating conditions that may be desired. From this human information, the ECU determines the required amount of engine fuel for each cycle in order to control fuel metering, and this information is used to control the engine's fuel consumption since fuel per cylinder per cycle is a measure of the engine load. Used to determine lubricant requirements.

The engine load ordinate and engine speed ordinate are used to determine the engine's oil requirements for a particular load and speed from a lookup map of fuel to fuel/oil ratio.

The fuel to oil ratio varies from 20:1 to 200:1 depending on engine load and engine speed conditions. next,
The determination of the fuel-to-oil ratio is used in conjunction with the calculation of fuel per cylinder per cycle to calculate the oil requirement per cylinder per cycle, and the engine cycles per second as determined by this information and the engine speed sensor. From this, the actual oil requirement of the engine per unit time is calculated, for example in milligrams of oil per second. This calculation is further dependent on any engine condition, such as engine temperature, and whether the engine is in a transition load condition, and whether the engine is operating with a wide open throttle or a fully closed throttle. It may also be modified by preset factors depending on other conditions deemed appropriate. This correction factor is then applied to the oil requirement to produce a corrected correct oil delivery rate per unit time. From this determination and the oil pump calibration, i.e. the amount of oil per pump cycle, an output signal is generated which determines the period of the pump cycle and provides the required pulse width between pump activations, thus scheduling the engine. Determine the pump supply cycle that matches the oil speed. If the maximum and minimum pump periods are set and the determined period is outside this range, the pump will operate at the appropriate end of the period range.

It has been found to be advantageous to energize the oil pump solenoid for 20 milliseconds per cycle. This is enough time to operate the pump one stroke, and the period of the energization cycle is 8
It varies between 0 milliseconds and 5 seconds at low oil speed.

The actual operation of the oil pump is carried out by energizing the electrical coil windings by the normal 12 volt electrical system normally used in electric trains and by providing a switching transistor driven by the output of the ECU.
This transistor periodically creates a ground connection between the coil and the negative side of the battery, thus energizing the coil when the switch is closed, grounding the circuit, and discharging the coil when the switch is opened. Forced.

A typical circuit is shown in FIG.

The oil pump and lubrication system described herein is used to supply oil to ignition engines operating on either two-stroke or four-stroke cycles. The oil pump and/or lubrication system described herein may be used in both vehicle engines, such as automobiles, and marine engines, such as outboard marriage engines.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of a pump device incorporating two pumps driven by one solenoid, Fig. 2 is an enlarged view of the piston skirt and piston head of Fig. 1,
3 and 4 are schematic diagrams of two separate lubrication systems of a two-stroke cycle engine incorporating the pump arrangement of FIG. 1; FIG. 5 is a logic diagram of the electronic control of the lubrication system of FIG. 2; Figure 6 is an electrical circuit diagram for oil pump control. ]...Housing, 2...Cylindrical core, 3...
Coil winding, 4... Armature, 5... Spring, 6... Inner annular shoulder, 7... Annular end, 8...
Inner cylindrical surface, 9... Annular gap, 10... Cylindrical end, 11... Cylindrical tube, 12.13... Skirt portion, 14.15... Cylinder, 16.17.・・Piston head, 18° 19・・Guide, 20.21・
... Pin, 22.23 ... Hole, 24.25 ... End wall, 26.27 ... Discharge port, 28.29 ... Ball valve, 3
0.31...Spring, 35.36...Working chamber,
37... Nipple, 40° 41... Hole, 42.43
... radial direction surface, 44 ... radial direction passage, 110.
...Sensor device, 115...Electronic control device, 120
...Oil pump, 121゜122...Duct, 1
23,124... Nozzle, 130... Injector, 131... Total; device, 141... Bearing duct, 142... Cylinder duct. Applicant's agent Sato-yu FICy, 3 14〉 Clear IF of drawings (no change in content) 1? Shibu - Manpower Fl (y, 5 Procedural Dispute Official Book (Method) February 7th, 1988 1'.1 Commissioner of the Patent Office Mr. Kunio Ogawa Ward Σ'' 1. Indication of the case 1988 Patent Application No. 259438 No. 2, Name of the invention Internal combustion engine lubrication system and pump 3, Relationship to the amended case Patent applicant Orbital, Engine Company, Proprietary, Limited 4, Agent (zip code 100) Chiyoda, Tokyo 3-chome Exit 2-3 Marunouchi Ward Telephone Tokyo (211) 2321 Representative December 240, Showa 62 (Delivery date January 26, 1988) 6. Drawings subject to amendment 7, 8 of the amendments

Claims (1)

[Scope of Claims] 1. A pump device that has a constant discharge amount for each cycle and supplies oil to a specified position of the engine, and a pump device that can be operated to generate periodic motion and that is capable of cycling the pump device at a constant rate. an electric device connected to drive the engine; a device for detecting specified engine operating conditions and thereby determining the amount of oil required at said specified location; a device operable in response to the specified oil requirement for controlling the cycle of the electric device in relation to the oil requirement. 2. The pump device is adapted to provide two separate oil supplies per pump cycle.
Internal combustion engine lubricating device as described in . 3. The internal combustion engine lubricating system according to claim 2, wherein the two separate supply amounts are different constant amounts of oil. 4. The pumping device has two positive displacement pumps each having a constant supply amount per cycle, the motorized device is capable of sequentially moving in two opposite directions for each cycle of the motorized device, and the pump is Claim 2, wherein one of the pumps is connected to the electric device so as to supply oil in response to movement in one direction and the other pump to supply oil in response to movement in the opposite direction. The internal combustion engine lubricating device described. 5. According to any one of claims 2 and 4, the electric device includes an electromagnetic device that is sequentially energized and deenergized to complete one cycle thereof. The internal combustion engine lubricating device described. 6. The pump device includes a cylinder with one end closed, a valve-controlled outlet provided at the closed end, and a piston that moves in the cylinder in an axial direction and forms a working chamber between the cylinder and the closed end. a skirt portion drivingly connected to the piston to periodically reciprocate the piston within the cylinder, the piston being slidably received within the cylinder in a substantially sealing manner; a head portion in facing relation to the closed end of the cylinder, the head portion being supported for constant axial movement relative to the skirt portion;
The head portion and skirt portion are responsive to the constant axial movement to selectively communicate between the working chamber and a feed portion of the cylinder opposite the head portion such that the piston moves away from the closed end of the cylinder. Claim 1: When oil can flow from the head part into the working chamber and when the piston moves in the opposite direction, the flow of oil between the working chamber and the supply part of the cylinder is blocked. Internal combustion engine lubricating device as described in . 7. The head portion and the skirt portion of the piston define an annular radial passage therebetween that periodically opens and closes in response to periodic reciprocation of the piston within the cylinder. Internal combustion engine lubricating device as described in . 8. The head portion forms an annular axial passage with the cylinder, and when the passage is open, forms an axial annular passage providing communication between the passage and the working chamber for allowing oil to flow into the working chamber. An internal combustion engine lubricating device according to claim 7. 9. The skirt portion and head portion of said piston are in substantially radial opposed relation such that when they are axially separated and abut against and close said radial passageway, they form opposing walls of said radial passageway. An internal combustion engine lubricating device according to any one of claims 7 and 8, each having an annular surface in a direction. 10. The electric device includes a reciprocating drive member, and the piston skirt portion is directly connected to the drive member so as to be able to reciprocate integrally with the drive member, and the piston head portion is configured to rotate each time the direction of movement of the drive member changes. Claims 6, 7, 8 and 9, wherein the drive member is indirectly connected to allow constant axial movement between the skirt portion and the head portion. internal combustion engine lubrication system. 11. A cylinder closed at one end, a valve-controlled outlet provided at said closed end, a piston movable axially within said cylinder and forming a working chamber between said closed end; a drive device for periodically reciprocating a piston within the cylinder, the piston being slidably received in a substantially sealing manner within the cylinder, the skirt portion facing the closed end of the cylinder; and a head portion supported for axial movement relative to the skirt portion, the head portion and the skirt portion moving in the working chamber in response to the axial movement. and a supply portion of the cylinder opposite said head portion, so that fluid can enter the working chamber from the head portion when the piston leaves the closed end of the cylinder; A pump in which fluid flow between the working chamber and the supply part of the cylinder is blocked when the piston moves in the opposite direction. 12. The head portion and the skirt portion of the piston define an annular radial passage therebetween that periodically opens and closes in response to periodic reciprocation of the piston within the cylinder. pump. 13. The head portion forms with the cylinder an annular axial passageway, and when the passageway is open there is communication between the annular passageway and the working chamber for allowing fluid to flow into the working chamber. Pump as described. 14. The skirt portion and the piston portion are substantially radially opposed so as to form opposing walls of the radial passageway when they are axially spaced apart to abut and close the radial passageway. The pump according to any one of claims 11 and 12, having an annular surface. 15. The pump according to any one of claims 11 to 14, wherein the drive device is an electric drive device capable of operating at a variable cycle period. 16. The electric drive device has a reciprocating drive device, and the piston skirt portion is directly connected to the drive member so as to be able to reciprocate integrally therewith, and the skirt portion is reciprocated each time the direction of movement of the drive member is changed. 16. The pump of claim 15, wherein said piston head portion is indirectly connected to said drive member for constant axial movement between said piston head portion and said head portion. 17. The pump according to any one of claims 15 and 16, wherein the electric drive device causes the piston to make a constant stroke every cycle. 18. The pump according to any one of claims 15, 16, and 17, further comprising a device for controlling the cycle period of the electric drive device in accordance with a pump discharge request. 19. Any one of claims 1 to 10
An internal combustion engine having a lubrication system according to paragraphs. 20. An internal combustion engine according to claim 19, which operates on a 20.2 stroke cycle. 21. The internal combustion engine according to any one of claims 19 and 20, which is an automobile engine. 22. The internal combustion engine according to any one of claims 19 and 20, which is a marine engine.