DE60031463T2 - Four-stroke internal combustion engine - Google Patents

Description

CROSS REFERENCE ON RELATED REGISTRATION

These The application claims priority of January 25, 1999 preliminary U.S. Patent Application No. 60 / 117,215.

AREA OF INVENTION

The The present invention relates generally to four-stroke internal combustion engines. and more particularly to four-stroke internal combustion engines used in edge milling, blower devices, Suction devices, chain saws, other hand-held Power tools, snow throwers, generators, plant cutting devices like lawnmowers or other power devices for the outdoors be used.

BACKGROUND THE INVENTION

Lots handheld Power tools or other outdoor power devices are powered by electric motors or two-stroke internal combustion engines driven. Electric motors are due to the available Performance on specific applications for products that have a connection cord and on battery-powered products without a cord limited. conventional Two-stroke engines include a lubrication device in which the lubricant mixed with the fuel that allows the engine to in any position, such as upright, inclined, transverse, or headfirst to be able to operate. If, for example, a chainsaw The chainsaw can be used typically used in an upright, oblique or upside down condition become. In recent years has been approved by various official Asked to reduce emissions with all the small bodies Gasoline engines, in particular conventional ones Two-stroke engines, related. Because four-stroke engines do not need mixing of lubrication and fuel, so it is desirable, Four-stroke engines instead of conventional Two-stroke engines to use, as four-stroke engines compared to the amount of unwanted Emissions from conventional Two-stroke engines are released, usually release less unwanted emissions.

Was formerly However, it is believed that four-stroke internal combustion engines only for limited applications let insert, like lawn mowers, Snow throwers, generators or other mobile products with Wheels. It was assumed that these earlier four-stroke engines were too heavy and bulky, to use as user-worn performance tools allow. As it is also in the Generally, the oil is necessary store separately from the gas so that the oil can be used for greasing can, were conventional inexpensive Four-stroke engines not designed in any other than to be operated in a substantially upright posture, otherwise, if the engine is tilted or tilted significantly The lubricant will pollute the engine. Only recently has been considering also pulled a four-stroke engine in a hand-held power tool or can be used in other applications where the motor is in a tilted or tilted state can work.

The EP-A-0779412 is considered the closest State of the art. This document teaches an internal combustion engine which corresponds to claim 1 of the present invention. In contrast However, the present invention sees a stirring device for this purpose before that with the lubricating oil does not come into contact when the engine is in an upright position Alignment is located

SUMMARY THE INVENTION

Corresponding There is a need for a four-stroke internal combustion engine that is in many different positions of the engine work in the Location is.

This is achieved by the engine according to claim 1. Here an internal combustion engine comprises: a crankshaft; a crankcase, in which the crankshaft is housed; an oil reservoir disposed adjacent to the crankcase is and contains lubricant; a stirring device, in the crankcase is included; and at least one connection channel between the crankcase and the oil container. Both the Connecting channel as well as the stirring device are in places that are over the surface of lubricant when the engine is oriented that the container vertically under the crankcase and an engine cylinder is located.

The crankcase and the oil tank are separated by a partition, and the at least one Channel comprises an opening formed in the partition, the crankcase and the oil tank through the opening always communicate with each other, with the crankcase and the oil tank over the Channel communicate with each other, whereby the crankcase during the Operating properly lubricated because the lubricant can flow between the crankcase and the oil reservoir. Pressure pulsations in the crankcase cause a pressure difference between the crankcase and the oil reservoir, thereby a fluid flow through the connecting channel from the oil tank to crankcase is effected, and wherein the stirring device a device for stirring provides the lubricant that is in the crankcase.

Further Features and advantages of the invention will become apparent to those skilled in the art Review of the following detailed description, which claims and open the drawings.

SHORT DESCRIPTION THE DRAWINGS

1 is an exploded view of a four-stroke internal combustion engine according to the present invention.

1A is a perspective view of the four-stroke engine of 1 representing the engine as assembled for use, for example, in an edger.

2 is a cross-sectional plan view and a partial schematic view of the engine of 1 along the line 2-2 of 3 ,

3 FIG. 12 is a cross-sectional side view of the assembled engine of FIG 1 ,

4 is an enlarged view of part of the in 3 shown engine, the rotation ratio between a cam gear and a crank gear, a portion of a lubricant flow path and a portion of a venting system for in 1 shown motor represents.

5 is an enlarged view of part of the in 3 shown engine, which represents a piston in its bottom dead center position.

6 FIG. 12 is a schematic diagram illustrating another aspect of the present invention pertaining to the attachment of a connecting rod to a piston and a crankshaft. FIG.

7 is a perspective view taken along the line 7-7 of 9 which is a counterweight disposed adjacent to a main bearing of the crankshaft.

7A is a side view of the counterweight of 7 ,

7B is another perspective view of the counterweight of 7 ,

8th Fig. 3 is a perspective view illustrating a stirring device cooperating with a scraper located on a wall in the motor chamber to control the amount of lubricant coming into contact with the stirring device.

8A shows the rotational movement of the stirring device of 8th and how the scraper controls the lubricant coming into contact with the stirring device.

9 FIG. 12 is a schematic illustration of another aspect of the present invention illustrating the positioning of a crankshaft in a crankcase provided in a motor housing. FIG.

10 is a partial schematic view of an upper portion of the motor housing along the line 10-10 of 3 and represents the spatial relationship between a combustion chamber, a piston bore, an intake valve and an exhaust valve.

11 is a partial schematic view of a cylinder head along the line 11-11 of 3 and shows the spatial relationship between the combustion chamber, the piston bore, the intake valve, the off lassventils and sections of a spark plug.

12 FIG. 12 is a schematic view illustrating the route of an air-fuel mixture through an intake system to the combustion chamber and the path of the exhaust gas out of the combustion chamber through an exhaust system in an engine according to the present invention. FIG.

13 FIG. 12 is a partial cross-sectional view of an engine according to the present invention showing the state of the lubricant in the crankcase and an oil tank when the engine is in a head-up state.

14 FIG. 10 is a cross-sectional view of another embodiment of the present invention showing a starter system mounted on the rear of the four-stroke internal combustion engine. FIG.

The 15 - 18 FIG. 12 are schematic illustrations of two engine housings that may be manufactured using a mold and a molding machine. FIG.

19 FIG. 12 is a schematic view of a power edge mill employing another four-stroke internal combustion engine according to the present invention. FIG.

20 Figure 11 is a perspective view of a mudguard that at least partially surrounds a motor, wherein the mudguard is configured to enhance the overall assembly operations for the engine.

21 is a disassembled perspective partial view of the four-stroke engine of 19 ,

22 is another disassembled perspective partial view of the four-stroke engine of FIG 19 ,

23 is a perspective view of a motor housing with an attached muffler.

24 is an exploded perspective view of 23 ,

25 is a perspective view of the flywheel end of the motor housing of 23 represents.

26 is an enlarged partial cross-sectional view taken along the line 26-26 of 23 and provides a connection between the engine housing and muffler of 23 represents.

27 is an alternative connection between the engine housing and muffler of 26 ,

28 is a perspective view of the motor housing of 23 without the muffler.

29 is a front view of a like in 22 and 20 shown inlet separation device.

30 FIG. 10 is a cross-sectional view of the inlet separation device of FIG 29 ,

31 is a partial side view in cross section of the assembled engine of 21 and 22 ,

32 is an enlarged view of part of the in 31 shown engine, which represents a piston in its bottom dead center.

33 is an enlarged view of the relationship between the cover plate and the starter system with respect to the support of the starter system on the cover plate.

The 34 - 38 put different views of the in 33 shown starter pulley.

The 39 - 40 FIG. 12 are schematic illustrations of two engine housings that may be manufactured using a mold and a molding machine. FIG.

Before the embodiments of the invention explained in detail It should be made clear that the invention in its Application not to the design details and arrangements of Limited components is that listed in the following description or in the drawings are shown. The invention may have other embodiments and various ways to be put into action or carried out. It should also be understood that the language used here and terminology is used for descriptive purposes and not as limiting should be considered.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In 1A The drawings is a four-stroke internal combustion engine 20 represented according to the present invention. The motor 20 drives a conventional shaft, typically in a shaft tube 22 is housed, which in turn drives a device with a rotary head, a cutting line or a cutting blade, a rotary impeller or the like depending on the type of power tool in use (see, eg 19 ). In the 1A (and 19 ), which is typically used in conjunction with a hand-held power edger, is used for illustrative purposes only, and it should be understood that other power tools, such as those mentioned hereinabove, may utilize the four-stroke engine of the present invention. In other words, the engine of the present invention is generally preferably used in an orientation in which the device or working tool has an axis that is substantially parallel to the crankshaft axis. The engine of the present invention may also be aligned with the crankshaft when horizontal or vertical. The engine according to the present invention is particularly well suited for those applications where high revolutions per minute, eg 3,000 RPM up to 7,000-8,000 RPM and above may be required, and where power is below 1 to above 6 hp can be delivered. Importantly, whatever type of power tool is used in combination with the four-stroke engine of the present invention, the engine may operate at least temporarily in substantially any operating position of the power tool.

In 1 In the drawings, an exploded perspective view showing various components of the four-stroke internal combustion engine is shown 20 according to the present invention. In 1 A side-valve type engine incorporating the various features of the present invention is shown. Side-actuated type engines are sometimes referred to as "L" due to the positional relationship of an intake valve and an exhaust valve with respect to a combustion chamber. Designated head motors. As will be seen below, "L" refers to the path taken by an air / fuel mixture and exhaust gas through respective valves and orifices found in the engine block. It is also important to note that in an "L" Head engine, the intake valve opening and the exhaust valve opening are in the engine housing and not in the cylinder head, as is common in engines with top-controlled valve or overhead cam.

Before the various features of the present invention are described in detail, the in 1 shown components for clarity. Shown are an ignition coil screw 24 , which is used to a (not shown) ignition coil on the engine 20 to install; Abdeckblechschrauben 27 attach a cover plate 26 on a motor housing 28 ; cover screws 30 attach an oil pan cover 32 and an oil pan cover gasket 34 on the motor housing 28 to one end of the motor housing 28 close tightly; Head Bolt 36 attach a cylinder head 38 and a cylinder head gasket 40 on the motor housing 28 and thereby at least partially form a combustion chamber 39 ( 2 ); a carburetor 42 and a muffler 44 are properly connected to the engine 20 connected; the carburetor 42 acts with an inlet opening 41 and an air purifier or air filter 43 ( 2 ) together; the muffler 44 acts with an outlet opening 45 together; a flywheel 46 comprising an integral impeller (not shown) is connected between the shroud by means of a flywheel key (not shown) 26 and the motor housing 28 attached to the engine 20 to cool during operation; a piston 48 is in a piston bore 50 in the motor housing 28 added; an inlet valve 52 and an exhaust valve 54 are adjacent to the piston bore 50 in the motor housing 28 arranged; an intake valve seat 56 and an exhaust valve seat 58 are in the case 28 used to with the respective heads of the valves 52 and 54 cooperate; valve springs 60 are housed in a valve spring chamber and in this by valve spring plate 62 supported; the valve spring chamber is through a valve cover 64 and a valve cover gasket 66 tightly closed; a crankshaft bearing 68 , a crankshaft bearing 70 , a worm or spiral gearbox 74 , a counterweight 76 , a crank pin 78 and a crankshaft 80 are part of a crankshaft system 82 ; the counterweight 76 includes an opening 77 ; a connecting rod 84 includes connecting rod bearings 86 and 88 ; one end of the connecting rod 84 is on the crankpin 78 attached, and a piston pin 90 connects the other end of the connecting rod 84 with the piston 48 by putting in one opening 92 of the piston 48 is inserted; the piston pin 90 acts when attaching the connecting rod 84 on the piston 48 with access openings 93 of the motor housing 28 together; a camshaft bushing 94 , a camshaft bushing 96 , a camshaft 98 , Cam hump 100 and 102 ( 2 ), and a worm or spiral gear 104 are part of a camshaft system 106 ; a cam cover 108 and a cam cover gasket 110 are by means of cam cover screws 111 on the motor housing 28 attached to the camshaft system 106 close tightly; tappet 112 are in the engine 20 positioned accordingly to the valves 52 and 54 cooperate; a spark plug 114 is in a spark plug receptacle in the cylinder head 38 used; a partition 116 with slits 118 . 120 and 122 is in the motor housing 28 arranged and at least partially forms a crankcase 124 and a lubricant or oil container 126 ; and the piston bore 50 includes an extension 128 at least partially in the crankcase 124 extends.

Other components and features that are in 1 are not clearly shown, are described below according to the features of the present invention.

1 shows the carburetor 42 and the muffler 44 placed on opposite sides of the motor housing 28 are attached. At the carburetor 42 it can be any type of carburetor that is tiltable, such as a standard variable passage venturi carburetor found in small gasoline engines, but a rotary valve carburetor, such as that available from Walbro, is particularly well suited for use in an engine according to the present invention. The (in 2 schematically shown) air cleaner or filter 43 is in or near an intake port in the carburetor 42 appropriate. A (in 1 not shown) fuel tank is typically at a bottom of the motor housing 28 attached and works with the carburetor 42 so together, that the inlet opening 41 ( 2 ) in the motor housing fuel and air can be supplied.

The motor housing 28 typically consists of lightweight cast aluminum alloy with a cylindrical bore or piston bore formed therein 50 , As noted, the piston bore is 50 designed so that they are partially in the crankcase 124 extends that in the motor housing 28 is arranged. The area or room 136 ( 13 ) between the extended piston bore 50 and the partition 166 Absorbs lubricant or oil during operation and storage to prevent excessive lubricant or oil from entering the piston bore 50 or a valve chamber 156 ( 2 ) entry. The piston 48 is preferably coated, such as with an iron coating, or chrome plated, so that no sleeve, such as an iron sleeve, is needed in the piston bore. Alternatively, the piston bore 50 include a cylinder liner made of iron.

The partition wall preferably comprises a lower slot 118 that is directly under the piston bore 50 located. Optional side vents 120 and 122 the partition 116 may be substantially directly across each other at a predetermined distance from the bottom of the piston bore 50 be arranged. The slots 118 . 120 and 122 can be replaced by one or more holes or holes. Of course, as noted, the present invention is not limited to a particular sized engine, but is applicable to any internal combustion engine. The design considerations to determine the size or arrangement of the slots or holes will become clear below. The slots or holes should be designed for different sized engines in consideration of the various features of the present invention.

The 8th and 8A show another view of the partition 116 , In operation, as shown, a counterweight 76 made to turn in one direction, usually in a clockwise direction. The lower slot 118 includes opposite sides 130 and 132 , The second page 132 points with regard to the direction of movement of the counterweight 76 adjacent to this a scraper 134 on. Preferably, the scraper 134 within 0.020 to 0.060 inches of the counterweight 76 arranged when this the scraper 134 is closest. The scraper 134 restricts or doses the amount of lubricant or oil (shown in broken lines) in direct contact with the counterweight 76 comes. The scraper 134 Helps to limit the amount of lubricant or oil entering the piston bore during operation 50 could be retracted, and reduces the rotational resistance caused by excess lubricant on the counterweight 76 arises. It should be noted that the scraper 134 could also be designed differently. For example, the lower slot could be 18 in the partition 116 act around a diagonal slot, leaving the second side of the diagonal slot as a scraper 134 works, but then it is not like in the 8th and 8A shown increased scraper. Alternatively, it could be at the bottom slot 118 in the partition 116 to act a straight slot without scraper function.

As noted shows 1 in the motor housing 28 arranged oil tank 126 passing through the partition 116 and the motor housing 28 is formed. The oil tank 126 is, preferably through the slots 118 . 120 and 122 in fluid flow communication with the crankcase 124 , As shown, the oil tank 126 and the partition 116 essentially curved or U-shaped. The partition 116 is preferably curved to remove lubricant away from the piston bore 50 to guide when the engine is tilted or reversed. The connection between the two chambers 124 and 126 ensures that the crankcase 124 can be properly lubricated during use because the lubricant between the two chambers during use 124 and 126 can flow, and that the lubricant during storage back into the oil reservoir 126 can flow, so no excess amount of lubricant in opposite directions into the piston bore 50 can flow.

With reference to the 1 and 3 is the crankshaft 80 in the crankcase 124 appropriate. The worm or spiral gear 74 the crankshaft drives the camshaft system 106 at. Helical or spiral transmissions are well known in the art and readily available from any number of drive manufacturers and suppliers. The crankshaft 80 and the gearbox 74 can be made in any number of known ways. However, the basic principles of the present invention would be well-matched if the gearbox were injection molded around a piece of cast metal. The injection molding material may be a thermoplastic material or nylon material known to those skilled in the art. Another alternative is to provide a metal crankshaft with an enlarged cylindrical metal piece on the crank on which a worm or spiral gear is to be placed. The crankshaft is then subjected to a hobbing process in which the gearbox is machined on the crankshaft.

Again with respect to the 1 and 3 are the bearings 68 and 70 around the crankshaft 80 positioned around the self-supporting crankshaft 80 support it when in the crankcase 124 is used. Camps 68 and 70 are on the opposite sides of the worm or spiral gear 74 and on the same side as the piston bore 50 arranged. The inner camp 68 is smaller in diameter than the outer bearing 70 , Camps 68 and 70 are dimensioned in this way so that the bearing pockets in the crankcase 124 can be found from one side of the motor housing 28 be processed using only one tool. As one skilled in the art will appreciate, processing one-way storage bags reduces equipment, time, and effort, usually associated with having to process storage bags from different directions.

As in 1 shown is the counterweight 76 at one end of the crankshaft 80 appropriate. The 7 . 7A and 7B show the shape and contours of the counterweight 76 in greater detail. As is generally clear, the forces resulting from the operation of the piston 48 , the connecting rod 84 and the associated components, by the counterweight 76 balanced. Depending on the size of the engine, more than one counterweight may be required. The counterweight 76 includes aerodynamic surfaces provided with round arches 138 and 140 , Each round arch surface includes a back 142 which are adjacent to the main camp 70 is arranged, and one of the back 142 opposite front 144 , The round arch surfaces 138 and 140 have profiled surfaces that extend from the back 140 to the front 142 of the counterweight 76 extend. In this way, the aerodynamic shape of the counterweight contributes 76 As will become more apparent below, this helps to maintain air resistance at the counterweight 76 to lower, thereby ensuring the correct air and lubricant swirling in the internal cavity of the engine 20 arises and the lubricant in the internal cavity of the engine 20 is steered.

The tool access hole or tool access opening 77 of the counterweight 76 ( 7 ) is used to position the crankshaft 80 in the crankcase 124 used. The 7 and 9 show schematically a tool 146 for the positioning of the external warehouse 70 , the counterweight 76 and the crankshaft 80 in the crankcase 124 is used. The warehouse 68 gets into the crank chamber by press fitting 124 installed and for receiving one end of the crankshaft 80 customized. Once the crankshaft 80 is made, the stock becomes 70 by press fit on the crankshaft 80 appropriate. Then the counterweight 76 on the crankshaft 80 appropriate. 7A takes a step 141 in which there is a margin of approximately 0.050 inches between the counterweight 76 and the camp 70 will be produced. As in 7 is shown are only sections 69 the outer raceway of the main camp 70 only after the counterweight 76 on the crankshaft 80 was attached. The access opening 77 allows the tool 146 ( 9 ) the outer raceway of the main warehouse 70 can touch in three places when the crankshaft 80 and associated components of the crankshaft system 82 in the crankcase 124 to be built in. A fourth leg of the tool ( 9 ) touches the cantilevered end of the crankshaft 80 , This system helps to make sure deliver that to the main camp 70 not damaged during assembly and the crankshaft 80 when inserting into the crankcase 124 stored properly.

6 schematically illustrates how the connecting rod 84 on the crankshaft 80 and on the piston 48 is attached. A commercially available shoulder screw (not shown) may be used to connect the connecting rod 84 on the crank pin 78 moor. The entire crankshaft system 82 ( 1 ) gets into the crankcase 124 ( 3 ) built-in. The piston 48 is from the top of the motor housing 28 into the piston bore 50 inserted. The opening 92 in the piston 48 comes with the access opening 93 in the motor housing 28 put in a line. The connecting rod 84 is by means of the crank pin 78 on the crankshaft system 82 attached and in a recess section 148 of the piston 48 positioned. The piston pin 90 is through the access opening 93 of the motor housing 28 in the access opening 92 of the piston 48 and through the camp 86 the connecting rod 84 plugged in. Because the opening 92 of the piston 48 not through the whole piston 48 is drilled, comes one end of the piston pin 90 on an interior section 150 of the piston 48 in Appendix. The piston pin 90 can in the piston 48 through a toothed disc 151 held in place in the open end of the opening 92 is used (see also 5 ). Preferably, the piston pin 90 and the crankpin 78 hollow to lower the total weight of the reciprocating mass, which in turn means that a smaller, lighter counterweight is needed to balance the forces generated by the lift mass. Lowering the overall weight of the lift components improves vibration performance and makes the engine easier to use.

The camshaft 98 , the eccentric cam bumps 100 and 102 , and the cam gear 104 are in 2 shown as separate parts. It should be noted that these parts can also be injection molded as a single component using, for example, a thermoplastic or nylon material. Alternatively, some components may be injection molded around a piece of cast metal to make the finished assembly in a similar manner as for the crankshaft 80 and the worm or spiral gear 74 was considered.

2 represents the camshaft 98 a channel 152 includes. The 2 . 3 and 4 show that part of the camshaft system 106 ( 1 ) adjacent to the worm or spiral gear 104 at least one radial opening 154 that includes the channel 152 and crankcase 124 is open. The channel 152 and the opening 154 can in the appropriate sections of the camshaft system 106 drilled or formed in it. In essence, the channel work 152 , the opening 154 and the camshaft system 106 together to provide a venting arrangement for the internal combustion engine, which will be outlined in more detail below. In addition, the radial opening can be 154 in a (not shown) radial disc on the camshaft system 106 in close proximity to the drive 103 is attached, so that they are with the channel 152 and the crankcase 124 communicates.

As shown, the camshaft is 98 perpendicular to the crankshaft 80 arranged. As will be apparent to those skilled in the art, in typical small gasoline engines, the cam and crankshaft are generally parallel and not perpendicular to one another, as shown in accordance with the present invention. A parallel arrangement results in a wider engine whereas the vertical arrangement of the present invention results in a longer engine design with the crankshaft axis substantially parallel to the longitudinal axis of the tool. A longer unit is particularly desirable in handheld applications such as power edgers, which require better balance for ease of operation. A wider motor may also have a tendency for the unit to rotate in the hands of the operator during use.

2 shows that the camshaft 98 in bushes 94 and 96 sitting in respective pockets inside the crankcase 124 in the motor housing 28 lie. The worm or spiral gears 74 and 104 ( 2 and 3 ) are preferably designed so that when the camshaft 98 generally perpendicular to the crankshaft 80 is used, the transmission 74 and 104 mesh so that the rotation ratio between crankshaft 80 and camshaft 98 2 to 1.

The valve tappets 112 , the inlet valve 52 and the exhaust valve 54 work with the camshaft 98 together ( 2 ). The inlet valve 52 and the exhaust valve 54 are in the motor housing 28 adjacent to the piston 48 and the piston bore 50 arranged. The valves 52 and 54 are positioned so that the valve heads are closer to the center line of the bore compared to the lower sections of the valves 50 lie ( 3 ). Preferably, the valves 52 and 54 at an angle of approximately zero to eight degrees from a line parallel to the centerline of the bore. The intake valve seat 56 and the exhaust valve seat 58 are in the motor housing 28 arranged and act with the heads of the valve 52 respectively. 54 together, to change selnd a seal to or opening in the combustion chamber 39 with regard to the openings 41 and 45 to accomplish. The valve spring plate 62 and the valve springs 60 are in the valve chamber 156 positioned ( 2 ). Each valve lifter 112 includes a respective head 158 which is in functional contact with the respective cam lobes 100 and 102 is. When the camshaft 98 by virtue of the drive gear 74 turns, take the cam bumps 100 and 102 the valve tappets engage properly, leaving the valves 52 and 54 move up and down as is well understood by those skilled in the art.

With reference to the 2 . 3 and 4 is the crankcase 124 with the valve chamber 156 over a passage or an opening 160 in connection. In addition, there is the valve chamber 156 with the piston bore 50 over a passage or an opening 162 in connection. The passages 160 and 162 allow the valve chamber 156 and the components therein during operation of the engine 20 in substantially any position lubricants can be obtained. In addition, it remains or flows with the help of the partition wall 116 , the extended piston bore 50 and the slots 118 . 120 and 122 during storage, no large amount of lubricant in or in the valve chamber 156 ,

With reference to the 1 . 2 and 3 is the cylinder head gasket 40 between the cylinder head 38 and the motor housing 28 used to provide a proper seal between these two. The spark plug 114 juts into the enclosed combustion chamber 39 in front. The spark plug 114 ignites, together with the ignition coil and a magneto ignition (not shown) to provide the necessary charge or high voltage signal to the air / fuel mixture in the combustion chamber 39 to ignite when the engine is in the ready state.

The 10 and 11 show at least partially schematically the combustion chamber 39 with regard to the inlet valve 52 , the exhaust valve 54 and the piston bore 50 , As shown, the combustion chamber extends 39 only partially over the piston bore 50 out. The orientation and shape of the combustion chamber 39 improves the vortex flow in the mixing chamber 39 to provide a better air / fuel mixture for better ignition of the mixture. Also is the spark plug 114 closer to the outlet valve 54 as at the inlet valve 52 positioned. An electrode 164 is properly aligned to provide a spark. By the spark plug 114 closer to the outlet valve 54 can be burned earlier, hotter air / fuel mixture through the ignited by the spark flame front. This reduces the auto-ignition tendency of the hotter air-fuel mixture at the outlet side of the combustion chamber 39 , Would the spark plug 114 closer to the inlet valve 52 There would be a risk that two burns would take place, which would lead to a loss of energy.

As in 2 are shown are the inlet opening 41 and the outlet opening 45 arranged 180 degrees apart. The location of the valves 52 and 54 is a result of the substantially vertical arrangement of the camshaft 98 and crankshaft 80 and allows the openings 41 and 45 on opposite sides of the motor housing 28 can be recognized. This provides an additional feature of operator safety. For example, if a power edger is used, the exhaust ports are 45 and the muffler 44 ( 1 ) while away from the operator during use. Another advantage, the openings 41 and 45 as far as possible from each other to set apart, is a heat transfer from the outlet opening 45 to the inlet opening 41 which, if it occurred, could lead to a self-warm start, misfire, or difficulty in adjusting the air / fuel ratio.

12 shows, if necessary with reference to the 2 and 10 , A schematic representation of the way the air / fuel mixture and the exhaust gas through the engine 20 takes. The air / fuel mixture enters the inlet port 41 a, passes through the inlet valve 52 , and enters the combustion chamber 39 , The motor 20 burns the air / fuel mixture to generate energy, and the remaining exhaust gas passes through the exhaust valve 54 and exits the outlet port 45 out. The arrangement of the camshaft 98 and the crankshaft 80 is also shown to illustrate how such an arrangement contributes to the overall scheme with the air / fuel and exhaust paths through the engine 20 connected is.

One important feature of the present invention is that the four-stroke engine according to the present invention substantially in any position can be used. A problem of conventional four-stroke engines is that when the engine is significantly tilted, the lubricant to unwanted Bodies flows, such as to the carburetor, causing a malfunction of the engine or he will stop working altogether right away. The four-stroke engine after The present invention is designed to address this problem and others To solve problems, typically with conventional Four-stroke engines are related.

The oil or lubricant container 126 , the crankcase 124 , the piston bore 50 and the valve chamber 156 include strategically placed slots, passages or openings so that the various functional parts in the engine can be lubricated virtually any time during use. In addition, the counterweight was 76 together with the partition 116 designed so that only a reasonable amount of lubricant with the counterweight 76 comes into contact. The design of the counterweight 76 It also allows it to dose the amount of lubricant that makes its way to the main bearing 70 does not look for the part of the crank chamber 124 to flood the drives 74 and 104 encloses. This also helps to prevent over the passage 160 and 162 too much lubricant in the valve chamber 156 entry. In addition, the piston bore 50 and partition 116 designed to ensure that the lubricant always has a location where it can flow, whether the engine is in service or stored, so as not to contaminate the internal components of the engine.

The piston bore 50 , the connecting rod 84 , the crankshaft system 82 , the camshaft system 106 , the valve chamber 156 and all components contained therein all require a certain lubrication. It is a feature of the present invention to use a minimal amount of lubricant or oil to lubricate the engine. This is done in several ways. First, assuming that the engine is in an upright (spark plug top) position, the topmost part requiring lubrication is the valve chamber 156 , Second, the rolling bearings need 86 and 88 for the connecting rod 84 less lubrication compared to a massive shaft with aluminum bushes. Third, as the lubricant follows the path of least resistance, it carries the bulkhead 116 , the counterweight 76 and the various above-mentioned slots, openings and passages to direct the lubricant to specific areas of the engine depending on the attitude of the engine.

In an upright resting position, the lubricant or oil in the oil or lubricant container 126 maintained. In this position and in this state, the level of the lubricant is preferably below the lower slot 118 in the partition 116 , During operation, the oscillating motion of the piston generates 48 Pressure pulses in the internal cavity of the engine 20 , The lubricant moves in response to the stroke of the piston 48 , The counterweight 76 moves the lubricant or oil and the blowby gas in the internal cavity of the engine 20 , When the piston 48 As the intake and power strokes move down, the lubricant will leak through the main bearing due to the pressure increase in the engine cavity 70 pressed to the bearings 70 and 68 , the worm or spiral gears 72 and 104 , the crankshaft 80 , the camshaft 98 and the jacks 94 and 96 lubricate. The effect of the cam gear 104 put some lubricant in the opening 160 enter and into the valve chamber 156 get there. In addition, any oil that could be in the piston bore 50 is present in the opening 162 be pressed to also the valve chamber 156 to lubricate. During upward strokes, ie the compression and suction strokes, the lubricant is retracted over the just mentioned areas due to a partial vacuum in the engine cavity to further lubricate the components. The oscillating motion of the piston 48 Moves the lubricant in the internal cavity of the engine 20 back and forth. The invention does not need a control valve to control the movement of the lubricant.

There are at least a few issues to keep in mind when lubricating the engine 20 is explained. First, resistance or energy is lost when the counterweight 76 stirring the lubricant and blowing gas. Second, it is undesirable, the piston bore 50 and the valve chamber 156 Too much lubricant to supply, which, if this occurs, to damage the engine 20 could lead.

As noted, since the static oil level in an upright condition is preferably below the lower slot 118 is located, the counterweight dives 76 preferably not directly into the lubricant, although a direct dip could also be used. The more direct contact with the lubricant, the more energy is supplied by the engine 20 lost. So the least amount of lubricant resistance is needed. As mentioned, the counterweight is 76 designed to remove the lubricant from the main bearing 70 away and to the oil pan cover 32 to fling. The design of the counterweight 76 also limits the amount of lubricant entering the piston bore 50 is thrown. In this way, only a limited amount of oil seeks its way to the valve chamber 156 , The counterweight 76 is designed to reduce the amount of drag required by the counterweight 76 as it rotates through the lubricant and stirs it. Additionally reduces the design of the counterweight 76 Air resistance losses, creating a more powerful engine. It would be noted that, although the counterweight 76 As the device shown and described, which circulates the lubricant and the sparging gas in the internal cavity, a separate stirring device could be provided to achieve the same results. In such a stirring device may be a baffle plate or a mixing device, the be or on the rotating crankshaft or connecting rod be is solidified or rotated in any number of other ways.

In a like in 13 shown, upside down position (spark plug below) represent the extended piston bore 50 , the partition 116 , the slots 118 . 120 and 122 , and the passages 160 and 162 ( 2 and 3 ) ensure that the engine continues to function properly for at least a limited time or that it can be stored in that position without polluting the engine. During operation, the changing pressure pulses, the blow-by gas and the stirring device effect 76 that mixed the lubricant and in the cavity of the engine 20 is moved. Although some oil in the piston bore 50 is hurled, no significant amount gets there. It should also be noted that the access passage 162 is arranged so that the lubrication ring 166 in the piston 48 not about the passage 162 or beyond that moves when the piston 48 in the piston bore 50 moved up and down ( 5 ). Otherwise it would be possible that in the valve chamber 156 Lubricants find their way into the combustion chamber 39 which would burn the lubricant and cause excessive emissions.

The crank chamber 124 includes an area or room 136 between the extended piston bore 50 and the partition 116 to pick up oil or grease when the engine is tilted or turned upside down, as in 13 is shown illustratively. During storage, the slots allow it 118 . 120 and 122 that the bulk of the oil in the oil tank 126 can stay, and the area 136 between the partition 116 and the piston bore 50 then contains most of the remaining lubricant. It is assumed that any during use in the valve spring chamber 156 remaining oil is negligible and does not affect the operation of the engine significantly. What is important is that in the upside down position due to the positioning of the slots 120 and 122 above the oil the valve chamber 156 can not absorb any significant amount of oil.

To further explain certain features of the present invention, the oil reservoir should 126 with the crankcase 124 to be in contact for proper lubrication of the engine 20 to provide in essentially every operating position. The various described slots, passages, holes and openings fulfill at least two tasks. First, if the engine 20 In a sideways state, the slot leaves 120 or 122 in the partition directed down to the floor 116 Oil in the crankcase 124 run, wherein the pressure pulses are similar to when the engine was in an upright state, the lubricant through the lower slot 118 passes. Second, if for whatever reason, a substantial amount of lubricant during operation in the crankcase 124 arrives and the engine 20 shut off and turned upside down or sideways for storage, let the side vents 120 and 122 Oil from the crankcase 124 in the oil container 126 go over to prevent the Kobbohrung 50 and valve chamber 126 undesirably get a substantial amount of lubricant.

Another important feature of the present invention is blow-by gas from the crankcase 124 to be able to discharge by the blow-by gas is separated from the mixture of lubricant and blowing gas. As described, the camshaft 98 with a hollow channel 152 and properly positioned radial openings 154 Mistake. Regarding 2 includes one end of the camshaft cover 108 a nipple 168 attached to a flexible hose (shown schematically) 170 is attached. Although not shown, there may be an oil seal between the cam cover 108 and the motor housing 28 be used. When the pressure pulses the mixture of lubricant and purging gas through the main bearing 70 Press, the blow-by gas into the radial openings 154 and the channel 152 driven while the oil due to the centrifugal action of the working camshaft 98 is prevented by the openings 154 pass. The blow-by gas flows through the cam cover 108 and the on the cam cover 108 attached nipple 168 , through the flexible hose 170 and back into the inlet port of the carburetor 42 , A check valve may be between the end of the camshaft 98 and the air inlet system to maintain the negative pressure created in the engine.

14 shows a cross-sectional view of the four-stroke engine according to the present invention with a starter device 172 attached to the sump cover plate 32 with screws 30 is attached. A crankshaft adapter 174 is on a crankpin 78 connected. A clutch bearing 176 is by interference fit around the crankshaft adapter 174 appropriate. A starter shaft 178 is about the clutch bearing 176 arranged around and on the starter 180 bolted or molded. An oil seal or an O-ring 181 is about the starter shaft 178 used around a seal between the starter device 172 and the sump cover 32 provide. A balance disk or thrust bearing 182 is on everyone Side of the starter 180 used. At the starter 180 it is preferably a cable starter with a pull cord 184 , An arrangement of the starter device 172 or the sump cover 32 on the back of the engine 20 allows the operator to have easy access to the drawstring. It also reduces the integral connection of the starter with the piston 48 over the connecting rod 84 and the crankshaft 80 over the crank pin 78 the line traction, to start the engine 20 necessary is. Alternatively, other starter systems may be used.

The 15 to 18 illustrate a design for molds used to make a motor housing according to the present invention. The motor housing is designed so that two motor housings can be manufactured using a mold and a molding machine. The motor housing is designed to include walls that provide the necessary clearance angles with certain different orientations for each motor housing in the mold. The clearance angles allow the motor housing to be effortlessly released from the mold. The motor housing is designed to allow access of a pusher tool (ie, the piston and camshaft bores) when two motor housings are made from one tool. In the 15 to 18 For example, the dies are shaped so that the center lines of the engine cylinder bores (which are parallel to the direction C) are parallel to each other. The boxes 194 and 196 represent the edges of the tool. By positioning the molds in this way, the inserts used to form the molds are inserted only along a few directions, ie in the directions A, B and C. This mold design reduces the overall space needed to make the molds Motor housing is necessary, but still allows that two motor housing can be made simultaneously. The two mold halves 188 . 190 be along a dividing line 192 separated. It should be noted that the rear wall of the motor housing is not shown and separately formed and then secured to the motor housing with screws or other suitable fasteners. However, it would also be possible to form the backplane in accordance with the principles set forth above integral with the motor housing. It should also be noted that the dividing line 192 could also be moved to another location. The clearance angles of the outer walls of the motor housing would then change accordingly to accommodate the new location of the parting line.

The 39 to 40 represent another embodiment of the design for the mold 529 which is used to manufacture a motor housing according to the present invention. In this embodiment, it is still possible to manufacture two motor housings using a mold and a molding machine. Form 529 is designed so that the center lines of the piston bores are parallel but run in opposite directions. In addition, the cavities are aligned so that the fixed material body form the internal features of the oil reservoir, the Absperrwand and the inner crankcase. The motor housing is designed to include walls needed for clearance angle line jumps and gate shutters for the respective alignment in the mold assembly. By aligning the mold in such a predetermined manner, the inserts for the mold parts are inserted only along a few directions, ie in the directions D, E, F and G. This embodiment of the mold design also serves to minimize the overall space reduce, which are required for the production of the two-motor housings from a single mold.

With Such a design of the form will become the target values or Key features for both cavities through one and the same piece created stationary material. By referring to these references and the same piece stationary material, there is less variance at the case, which would have to be compensated during the processing of the finished motor housing. This presses yourself as well even with less variance in the finished motor housing, even if the case of two separate cavities is derived.

As shown, in this embodiment, the flywheel mounting plate is also integrated into the engine housing casting. It is also desirable to have a form-cutting 531 of the casting in the top of the cylinder and to direct the mold cuts parallel to the directions F and G in the cavities.

The in 1 shown engine 20 has been described as indicating the various aspects of the present invention. However, the features of the present invention described above can also be incorporated into other designs of four-stroke internal combustion engines. Moreover, the above features can be easily modified to suit different engine designs. As such, the 19 to 40 another four-stroke internal combustion engine, in which the features described above can be used, and in the additional inventive feature which have not yet been described. It should be noted that specifically in conjunction with the 19 to 40 described features in the in the 1 to 18 can be recorded in the engine described or in other engines.

19 represents a four-stroke internal combustion engine 300 according to the present invention. The engine 300 is shown as being used in a power edger, but can also be used in any of the other engines 1 described devices are used.

Again, before describing in detail the various features of the present invention, those described in U.S. Patent Nos. 5,135,355 and 4,324,237 are described 21 and 22 shown components for clarity shown. Many of the components are assembled in the same or a similar way as with respect to 1 or as will be understood by one of ordinary skill in the art. Accordingly, the manner of assembly will not be described in detail below unless the manner of assembly is one of the specific features of the present invention. Such features will be provided, if necessary, in more detail with reference to the drawings that follow. In 21 are shown: a spark plug 302 ; Head Bolt 304 ; a cylinder 306 ; a cylinder head gasket 308 ; compression rings 310 and 312 and a lubrication ring 313 , which are arranged appropriately in annular slots, which are located in a piston 314 are located; a connecting rod 316 and connecting rod bearings, preferably needle roller bearings 318 and 320 ; an outlet valve 322 , an inlet valve 324 , Valve springs 326 and valve spring plate 328 ; a motor housing 330 , a valve cover 332 and associated screws 334 ; a flywheel 336 , a crankshaft adapter 338 , an ignition coil 340 , Wiring systems 342 and 346 , and screws 344 of which all belong to the starter system; Muffler mounting bolts 350 ; a muffler 352 ; and a blower housing 348 , which is part of a total protection cover, which will be further described below.

In 22 are shown: an O-ring seal 366 and an oil stick 367 ; an inlet seal 368 , a Einlassstrenner and screws 370 ; a carburetor gasket 372 , a carburetor 374 and an O-ring 376 ; an air filter system 378 , Screws 380 and an air filter cover 382 ; a piston pin 384 and a pulley piston pin holder 386 ; an oil seal ring 388 , Roller bearing 390 , a crankshaft 392 and a counterweight 393 ; an oil pan cover 394 and screws 396 ; a muffler housing 398 , which is part of a total protection cover, which will be described later, and mounting screws 400 ; tappet 402 , a camshaft 404 , a camshaft cover 406 ; screw 408 and a vent pipe 410 ; a check valve 411 ; a fuel tank 412 with a fuel line 414 , opposite shoulders 416 ; and filler 418 , around the shoulders 416 is arranged around, as will be described below.

Other components and features included in the 21 and 22 are not clearly shown, are described below. In addition, the meaning of each of the in the 21 and 22 shown component or their interaction in connection with the principles of the present invention.

23 shows the motor housing 330 with that by mounting screws 350 attached muffler 352 more clear. The motor housing 330 includes a crankcase 420 and a cylinder 422 , The cylinder head 306 ( 21 ), which at least partially forms a combustion chamber, is adjacent to the cylinder 422 arranged. A crank chamber 426 is in the crankcase 420 intended. An oil container 428 is also in the crankcase 420 arranged and in fluid communication with the crank chamber 426 , preferably via a slot 430 and opposite openings 432 (of which only one is shown) in a partition 433 are provided. The partition 433 is in the crankcase 420 arranged and at least partially subdivided the crank chamber 426 and the oil container 428 , Several openings 434 are so in the motor housing 330 provided that the sump cover 394 and the sump cover seal can be attached thereto. The motor housing 330 also includes an oversized piston pin boss 436 , The piston pin projection 436 can be integral with the dividing wall 433 be educated. The function of the piston pin projection 436 will be described in more detail below. The motor housing 330 also includes a flywheel mounting plate 438 with at least one mounting projection 440 whose function will be described below.

24 is an exploded perspective view of 23 and shows how the muffler 352 to the motor housing 330 is connected. The cylinder 422 includes an outlet opening 442 and an inlet opening 444 ( 25 ). Preferably, the outlet opening 444 and the inlet opening 442 elliptical in shape, reducing the overall height of the motor housing 330 can be reduced. This Of course, it also reduces the overall weight of the motor housing, which is a particularly important factor in handheld power tools. The walls of the openings 442 and 444 are provided with sufficient material to the weight of the motor housing 330 and the cylinder head arranged above 306 to wear.

The muffler 352 includes a survey 446 , which is preferably cylindrical. The assessment 446 extends into the outlet opening 442 , Mounting screws 350 extend through openings 448 in the muffler 352 and in openings 450 inside, in the cylinder 422 are formed. Preferably, the openings 448 spaced and on opposite sides of the outlet opening 442 arranged to the stability of the muffler 352 in terms of its connection to the cylinder 422 as large as possible.

The 26 and 27 are enlarged partial cross-sectional views along the line 26-26 of 23 and show preferred alternative mounting connections between the muffler 352 and cylinders 422 , 26 shows the motor housing 330 with an angled step sealing surface 452 in the outlet opening 442 of the cylinder 422 is arranged. The end 454 the survey 446 may be the outlet opening sealing surface 452 to substantially prevent exhaust gas from undesirably escaping into the environment. Preferably, a seal 456 between the end 454 the survey 446 and the sealing surface 452 used to prevent the escape of exhaust even better.

27 shows the outer lining of the survey 446 the muffler 352 that from the area 458 the outlet opening 442 surrounded, creating a gap 460 is formed in between. Although the area 458 is shown as an angled surface, it can also assume a different design, as long as only a space between the muffler 352 and the outlet opening 442 consists. A seal 462 is between the muffler 352 and the cylinder 422 or the motor housing 330 used to the gap 460 seal, which prevents exhaust gas escapes into the atmosphere. Preferably, it is the seal 462 around an enlarged seal between the motor housing 330 and the muffler 352 also serves as a heat shield.

The muffler 352 ( 24 ) preferably comprises a pair of outer shells 464 and 466 with respective mounting screw holes 448 for the mounting screws 350 , An inner shell or baffle plate (not shown) is preferably between the outer shells 464 and 466 arranged. The inner shell is also designed so that the mounting screws 350 can pass through them. The baffle is designed to reduce sound. The outer shell 464 includes a shoulder 470 , which are around an edge of the outer shell 464 extends around. The outer shell 466 includes a flange (not shown) that extends around an edge of the outer shell 466 extends around. When assembling takes the shoulder 470 the flange on so that when exhaust from the muffler 352 exit, this exits the engine away. Although not shown, a baffle may be over the outlet openings 372 ( 23 ) of the muffler to protect the operator from being exposed to a direct exhaust stream.

Due to the nature of the four-stroke engine according to the principles of the present invention, it is desirable to provide a fuel-efficient engine with features that make it easy to assemble the engine. One feature is to have one and the same engine housing 330 For engines with different horsepower ratings, just use the connecting rod 316 ( 21 ) and thus the length of the piston stroke is changed. To accomplish this feature is the oversized piston pin boss 436 ( 23 ) intended. The piston pin projection 436 can at its upper end 474 machined to a (not shown) access opening in the crankcase 420 for a first piston stroke, and may at its lower end 476 machined to a (not shown) access opening in the crankcase 420 to provide for a second piston stroke. After the piston pin protrusion 436 was processed accordingly, the piston pin 384 ( 22 ) is inserted through the crankcase access opening and into the piston access opening to the piston 314 ( 21 ) with the connecting rod 316 ( 21 ) connect to. Accordingly, one and the same housing 330 be used for different sized engines. 31 shows a completed assembly of such an engine. 32 shows the piston 314 in its lowest dead center, leaving the piston pin 384 can be properly positioned in the engine.

28 is an enlarged view of the motor housing 330 from 24 without the muffler 352 , As shown, the dividing wall sets 433 a train 478 stuck, essentially around the dividing wall 433 and over the piston pin protrusion 436 extends. The train 478 leaves in oil tank 428 located lubricant around a substantial portion of the partition 433 flow to further improve the lubrication and storage features in accordance with the principles of the present invention. The train 478 It allows the amount of lubricant that accumulates on both sides of the dividing wall 433 is, compensates when the engine is turned upside down. This also prevents even a significant amount of the lubricant in the crank chamber 426 passes.

Another feature that lowers the cost of assembling the engine, and thus the overall cost of the engine, is related to the manner and manner of attaching a protective cover to the motor housing. As with respect to 23 was noted, is the flywheel mounting plate 438 with at least one mounting projection 440 Mistake. 25 is a perspective view of the motor housing 330 from 23 , only from a different perspective. As shown, the other side includes the flywheel mounting plate 438 also at least one mounting projection 480 , When assembling the engine 300 a mounting bracket (not shown) is applied to the motor 300 to keep. Every assembly advantage 440 and 480 picks up a separate pin (not shown) from the mounting bracket to the motor housing 330 to attach to the mounting bracket. A protective cover 482 ( 20 ) is provided so that it the motor housing 330 at least partially encompasses. Preferably, the protective cover closes the fan housing 348 (see also 21 ) and the muffler housing 398 (see also 22 ) one. The protective cover 482 includes at least one slot 484 , Every slot 484 is configured so that it surrounds a respective pin of the mounting bracket, resulting from the mounting protrusions 440 and 480 extends out when the protective cover 482 around the motor housing 330 is placed. The protective cover 482 can on the motor housing 330 be fastened by screws 486 ( 20 ) in respective openings such as the opening 488 ( 25 ) of the motor housing 330 be screwed. This allows the entire engine 300 essentially assembled while remaining attached to a single mounting bracket.

Another feature of the protective cover 482 is that the muffler housing 398 preferably several elevated sections 490 includes ( 31 ). That way, the engine can 300 if desired, be placed on the ground and then lie on the raised sections 490 on. It would be noted that the blower housing 492 ' from 31 something of that in 20 differs shown blower housing. This is to show that various suitable designs of protective cover 482 are possible without affecting the scope of the present invention.

As in 20 is shown is the protective cover 482 with an opening 494 provided which the inlet opening 444 surrounds ( 25 ). An inlet funnel 369 ( 22 ) with an air / fuel passage extending therethrough 496 ( 29 and 30 ) is provided. The inlet separator 369 is so on the motor housing 330 attached that the air / fuel channel 496 with the inlet opening 444 flees. The inlet separator 369 sits in the opening 494 the protective cover 482 In order to essentially ensure that cooling air is between the motor housing 330 and the protective cover 482 circulates, not through the opening 494 in the protective cover 482 can escape. To accomplish this feature, the inlet separator comprises 396 preferably an integrally formed rear wall 498 and a side wall 500 ( 22 ).

To further reduce manufacturing costs, the crankcase 420 , the cylinder 422 and the mounting plate 438 poured as a single component. In a preferred embodiment, the motor housing comprises 330 at least one integrally formed thereon rib 502 ( 28 ). The rib 502 extends from the mounting plate for stability and cooling purposes 438 and under the crankcase 420 ,

Although the protective cover 482 may be of many different designs, consistent with the principles of the present invention, it is designed to be the fuel tank 412 to keep. As in 31 best seen is the protective cover 482 with a pair of opposite fillets 504 provided (only one of which is shown). The outward-extending shoulders 416 (see also 22 ) are of the respective flutes 504 so taken up that the fuel tank 412 from the protective cover 482 is held. The filler 418 (see also 22 ), preferably a closed cell, high temperature and gasoline resistant high density polyethylene foam, is between each groove 504 and the respective shoulder 416 provided a tight fit between the protective cover 482 and the fuel tank 412 provide. The fuel line 414 ( 22 ) includes a fuel filter 506 that in the fuel tank 412 located end of the fuel line 414 is appropriate. It should be noted that the additional in 22 shown line is a purge line. The fuel filter 506 acts as a weight such that during operation of the engine, when it is tilted, the weighted fuel line 414 to the bottom of the fuel tank 412 pans to make sure of the fuel line 414 also fuel is taken up.

Another aspect of the present invention relates to in 33 starter system shown 507 , The blower housing 348 is with a hub 508 with an inward facing extension 510 Mistake. The hub 508 is designed to be on the crankshaft 392 ( 22 ) or the crankshaft adapter 338 ( 21 ) to be plugged. The starter system 507 that a pulley 516 , a rope 518 and a spring 520 includes, is on the hub 508 arranged. A toothed disc 514 is on the hub extension 510 set to dig into the extension material. The toothed disc 514 keeps the starter system 507 with regard to the blower housing 348 in place. This arrangement provides the need for separate mounting bosses and fasteners from the world that are typically needed to hold the starter system in place. Such mounting bosses and fasteners generally block the cooling airflow generated by a fan.

The 34 - 38 show different views of the pulley 516 , The feather 520 ( 33 ) is on a page 522 the pulley 516 with a suitably shaped annular recess 524 arranged. The other side 526 the pulley 516 includes several noses 528 for engagement with a flywheel, such as the in 21 shown flywheel 336 , The rope 518 includes a node 530 at one of its ends, in a chamber 532 held in a hub 534 the pulley 516 below the pulley cable section 536 is trained. The rope 518 extends through an opening 538 in the pulley cable section 536 and is around the pulley 516 wound. The other end of the rope 518 is at a starter handle 540 attached ( 20 ).

The The foregoing description of the present invention has been made for purposes the illustration and explanation played. About that In addition, the description is intended to describe the invention in the form disclosed herein do not restrict. Consequently, there are variants and modifications that are the above Lessons in the skill or knowledge of the related class equal to technology are, in the context of the present invention. The ones described here embodiments should explain the best ways to practical implementation the invention are known and other professionals on the Enable the invention as such, or others embodiments and to make use of various modifications by the particular Applications or use cases required by the present invention. The appended claims are intended be construed as having alternative embodiments to that extent include, as the prior art allows.

Various Features of the invention are set forth in the following claims.

LIST OF REFERENCE NUMBERS

Claims (4)

Internal combustion engine with: a crankshaft ( 80 ); a crankcase ( 124 ), in which the crankshaft ( 80 ) is housed; an oil container ( 126 ), which is adjacent to the crankcase ( 124 ) and contains lubricant; a stirring device ( 76 ) in the crankcase ( 124 ) is included; and at least one connection channel ( 118 ) between the crankcase ( 124 ) and the oil container ( 126 ), whereby both the connection channel ( 118 ) as well as the stirring device ( 76 ) are located at locations that are above the surface of the lubricant, when the engine is oriented so that the container vertically below the crankcase ( 124 ) and an engine cylinder; the crankcase ( 124 ) and the oil container ( 126 ) by a partition wall ( 116 ) are separated from each other, and the at least one channel ( 118 ) one in the partition ( 116 ) formed opening, the crankcase ( 124 ) and the oil container ( 126 ) always communicate through the opening, with the crankcase ( 124 ) and the oil container ( 126 ) over the canal ( 118 ), whereby the crankcase ( 124 ) can be properly lubricated during operation because the lubricant between the crankcase ( 124 ) and the oil container ( 126 ), whereby pressure pulsations in the crankcase ( 124 ) a pressure difference between the crankcase ( 124 ) and the oil container ( 126 ), whereby a fluid flow through the connecting channel ( 118 ) from the oil reservoir ( 126 ) to the crankcase ( 124 ) is effected, and wherein the stirring device ( 76 ) provides a means for stirring the lubricant, which is in the crankcase ( 124 ) is located. An internal combustion engine according to claim 1, wherein the at least one channel ( 118 ) several in the partition ( 116 ) provided openings. Internal combustion engine according to claim 1, wherein the partition wall ( 116 ) in the direction of the oil tank ( 126 ) is curved. Internal combustion engine according to claim 1, wherein the partition wall ( 116 ) about an axis of rotation of the crankshaft ( 80 ) is curved.