JPS61234211A - Valve for combustion chamber - 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 The present invention relates to combustion chamber valves, and more particularly to combustion chamber assemblies with rotary valves used in internal combustion engines (and can also be used mechanically in air motors and compressors). .

A rotary valve assembly for controlling intake gas into the combustion chamber of an internal combustion engine and exhaust gas from the combustion chamber, which periodically communicates the combustion chamber with the intake passage and exhaust passage. A rotary valve assembly is described that includes a rotary valve body having a passageway and surrounded by a sealing sleeve to create a gas seal during operation of the internal combustion engine.

U.S. Pat. No. 3,130,953 to Carpenter describes a tension sleeve that includes inwardly directed longitudinal keys provided at one edge of the split. (During rotation, this longitudinal key engages a groove in the rotary valve body to pull the sleeve around together with the rotary valve body) and depends on the particular relative position of the ports on the sleeve. . Thus, the edge of the sleeve with the key adjacent to the split is described as the leading edge, the opposite edge of the sleeve adjacent to the split is described as the trailing edge, and the port is located at the trailing edge. is located in close proximity to the key but far away from the leading edge, thereby reducing any negative impact on the sealing effect that may be due to tension on the key. The key is radial in order to prevent the leading edge of the sleeve from coupling with the rotating bore of the sleeve, yet the ports located near the trailing edge must maintain sealing pressure. is slightly inclined to the

U.S. Patent No. 4, issued to Hansen.
No. 494.500 describes a rotary valve assembly for an internal combustion engine having a rotary valve body surrounded by a cylindrical member preferably made of ceramic material. Because the cylindrical member is relatively thick and rigid, and because the cylindrical member has an unbroken but constant lateral movement along its length, the gas pressure within the combustion chamber acts to move the cylinder laterally; This seals the surface near the boat with the rotating bore of the cylindrical member. The universal joint allows eccentric drive of the rotary valve assembly. The rotary valve body is rotatably driven by a longitudinally oriented key located diametrically opposite a boat extending along the length of the rotary valve body and communicating periodically with the intake and exhaust passages of the engine. to the cylindrical sealing sleeve.

U.S. Patent Nos. 3.130.953 and 4,494.50
In both cases of No. 0, the rotary valve body is surrounded by a split sleeve or a cylindrical member, and the split sleeve shields the inner wall of the cylindrical member over its entire length in the longitudinal direction so that the split sleeve or cylindrical member is not exposed to the combustion chamber. That's what I do.

q amount per plate! It is an object of the present invention to provide a rotary valve assembly in which the sealing sleeve is exposed to the combustion chamber and thus directly exposed to the thermal pressures generated during engine operation. The metal sleeve of this structure can provide very effective cooling, thereby allowing high compression ratios giving thermal efficiency, as well as turbocharging or Enables supercharging.

Another purpose of creating such low temperatures is to reduce undesirable emissions including nitrogen oxides and lead compounds.

Another object of the invention is to provide such a sealing sleeve which can alternatively be made of a ceramic material suitable for very high temperature combustion in diesel cycles.

Another object of the present invention is to provide a rotary valve assembly in which a replaceable compression element can be received within the bore of the rotary sealing sleeve to adjust the compression ratio of an individual engine. There is a particular thing.

Another object of the invention is to provide a rotary sealing sleeve of the type in which the split portion of the sleeve extends over its entire length and is located directly above the boat provided in the sleeve.

A final object of the invention is to provide a mechanism for rotationally driving such a sleeve from the upper end of the sleeve, which maintains the sealing action of the sleeve.

A rotary valve assembly for an internal combustion engine according to the present invention comprises:
A sealing sleeve is rotatably mounted within the bore of the engine head housing the valve assembly, and the sleeve periodically communicates with an intake passage and an exhaust passage disposed in the engine head during rotation of the sleeve. have a boat
The lower end of the sleeve communicates with the cylinder of the engine in which the piston reciprocates, and the upper end of the sleeve is sealed.
The sleeve is directly exposed to the combustion chamber thus formed within the sleeve, the sleeve is split longitudinally along its entire length by a slit aligned with the boat, and the valve mechanism is inserted into the head above the upper end of the sleeve. and is adapted to rotationally drive the sleeve by engaging a drive formation located at the upper end of the sleeve.

The rotary valve assembly preferably further includes a replaceable compression element adapted to be removably attached to the valve mechanism within the upper end of the bore of the sleeve. By replacing one compression element with another, the compression ratio of the engine can be changed.

The sealing sleeve may be of simple cylindrical form;
It may have an integral inwardly directed flange at its upper end (
, or may be made of metal or ceramics.

The drive formation at the upper end of the sleeve may have a notch or peg that engages a corresponding formation on the valve mechanism. The drive formation at the upper end of the sleeve has an angular position relative to the slit, where the angle between the drive formation and the leading edge of the sleeve adjacent to the slit is such that the angle between the drive formation and the sleeve adjacent to the slit is more particularly, the former angle is no more than half the latter angle, preferably about 173 of the latter angle.

1 and 2, a rotary valve assembly for an internal combustion engine includes a sealing sleeve 40 rotatably mounted within a bore 18 of an engine head 12; The case is equipped with a bearing shell 20 made of phosphor bronze.

The engine head 12 houses a valve assembly, and the sleeve 40 has a boat 44 in periodic communication with an intake passage 30 and an exhaust passage 32 disposed within the head during rotation of the sleeve.
have. The lower end 40.1 of the sleeve 40 is open;
and communicates with the cylinder 16 of the engine, and this cylinder 1
The piston 16.1 reciprocates within the sleeve 40, and the upper end 40.2 of the sleeve 40 is sealed. Inner wall 40 of sleeve 40
．． 3 is directly exposed to a combustion chamber 100, which is thus formed within the sleeve above the crown of the piston 16.1. The sleeve 40 is attached to the boat 44
It is split longitudinally along its entire length by a slit 46 aligned with the slit 46. The valve mechanism 50 is located at the upper end 40 of the sleeve 40.
．． 2, the valve mechanism 50 is arranged in the head 12 above the drive formation 48 located at the upper end of the sleeve 40.
By engaging with the sleeve 40, the sleeve 40 is rotated.

A replaceable compression element 74 is removably attached to the valve mechanism within the upper end of the bore of sleeve 40. By replacing element 74, the compression ratio of the engine can be adjusted.

A drive formation 48 (in this case shown as a peg, but could also be a tooth-engaging slot depending from the valve mechanism) has a slit 46 in the upper end of the sleeve 40.2.
It is arranged at an angle 101 from the angular position of . The direction of rotation 102 of the sleeve during operation defines the leading edge 40.3 and trailing edge 40.4 of the sleeve 40 adjacent the slit 46. The peg 48 is angularly closer to the leading edge 40.3 than to the trailing edge 40.4, in fact in this example
01 is approximately 80°.

Referring to the overall structural arrangement, the bearing shell 20
is seated on shoulder 22 at the lower end of bore 18.

The bearing shell has two boats 24 and 26 aligned with an intake boat 30 and an exhaust boat 32, respectively. The bearing shell 20 has another opening 34 exposing a spark plug 36 of the surface discharge type. The bearing shell 20 has an outwardly directed peripheral flange 3 at its upper end.
The flange 38 has a bore 1 in the cylinder head.
It is seated in a groove at the top of the opening of 8.

The valve sleeve 40 is smooth, hollow cylindrical, and has a boat 44 and a longitudinal slit 46 that aligns with the boat and extends the length of the sleeve;
A drive peg 48 is arranged at the upper end 40.2.

The valve mechanism 50 includes a shaft 52 supporting a helical cut gear 52.1, which drives the sleeve 40 rotationally at half the engine speed in the direction indicated by arrow 102. It meshes with tooth 54.

The gear 56 is attached to the tap shaft 60.1 with a suitable key 60.2 at the upper end of the shaft 60. The lower end of the shaft 60 supports a disc-shaped portion 64 and the sleeve 40
The upper end 40.2 rests on the lower surface of this disc-shaped part 64. The disc 64 supports a graphite or ceramic ring seal 103 which is spring loaded by a spring washer 104, a polymeric ring such as P, T, F, E (Politetrafluoroethylene). Neoprene ring i 03. i is seated in the groove 103.2 of the disc 64 and seals against the ring 103. Journal 68 is bolted to head 12 and shaft 60
is pivotally supported, and further includes a thrust support surface 70,
When subjected to combustion chamber pressure, the upper part 69.1 of the disc 64 can abut this thrust support surface.

Oil passages 68.1 in the journal 68 direct excess oil from the thrust face to the oil tank 108 via channels 68.2. The underside of the disc 64 has a hole for receiving the drive peg 48 of the sleeve 40. The bolt 58 passes through the entire length of the washer 58.1 and the shirt 60 in the assembled state;
It is threaded into element 74 to hold the assembly together. Small locating pins 74.1 ensure precise alignment of elements 74. Element 74 has a sloped lower surface 74.2, leaving a substantial gap 105 between element 74 and sleeve 40.

When the engine is running, the drive force applied to sleeve 40 is approximately tangential at the location of the drive peg. (
This direction 106 is also shown, for example, in FIG. 4b). However, the contact direction 106 can be changed inwardly or outwardly by imparting an inclination to the peg (slot) support surface, indicated by the dotted line 1)0. The frictional forces acting on the outer surface of the sleeve 40 thus bring the area proximate the leading edge 40.3 into tight sealing contact with the bore of the bearing shell 20. The sleeve 40 may be provided with pegs and/or notches to provide a sloped flat surface to increase or decrease the outward sealing pressure on the leading edge 40.3. Assembled with light spring tension to keep shell 20 engaged, positive pressure within the combustion chamber increases its sealing pressure. Gas leakage at the upper end 40.2 of the sleeve 40 which occurs beyond the disk 64 is sealed off at the support surface by the sealing ring 103.

The walls of the sleeve 40 are substantially completely exposed to the combustion chamber and are subject to the heat and pressure of the combustion chamber. This ensures a good sealing with the sleeve and allows the selection of metallic materials for the sleeve in order to have a very good transfer of heat from the sleeve wall to the cooling channels 107 of the head 12. During 600 hours of testing at full power, the sleeve wall temperature was found to be around 230° C. at an engine speed of 3500 rpm+. During this test, a phosphor bronze bearing shell 20 and a 316 stainless copper sealing sleeve 40 were used.

The element was made from brass which provides rapid heat transfer and a low surface temperature of the element. Due to the low temperature of the walls of the combustion chamber thus formed, explosions were completely eliminated even when using low octane fuel at high compression ratios (87 octane fuel at a compression ratio of 14:1). This is particularly important in view of the move toward non-complexed fuels to achieve improved emissions. Cooling is further provided by an oil bath 108 in the head 12 that is used to lubricate the drive train. Lower temperatures help minimize the formation of nitrogen oxides, which further improves exhaust emissions.

The valve assembly is arranged so that the sealing sleeve 40 and/or element 74 can be replaced without removing the head from the engine. Thus, valve timing can be easily changed by replacing sleeve 40 with another sleeve that provides a different valve timing, and the compression ratio of the engine can be easily changed by replacing element 74 with another element. can be changed to

Lubrication has been achieved by adding small amounts of colloidal graphite to gasoline. It is also possible to use oil as a lubricant, and if oil is used, it is preferably injected from the cylinder head at a position downstream of the intake port every 40 to 50 strokes of the piston. If the lubricant is oil or graphite, the low temperature will cause the retention of a boundary layer within the bore of the bearing shell 20, even though the ports 44 of the sealing sleeve 40 will form a window through which the lubricant will wipe during operation. Therefore, it contributes to lubricant retention. The amount of lubricant can also be controlled depending on the load.

The shape of the port 44 of the sleeve 40 shown in FIG.
4 and is shown as a "rectangular shape" used in the exhaust passage 30, intake port 32, and exhaust port 44. However, for particularly high performance low speed operation, and for simple cylinder head constructions using circular intake and exhaust passages, the port configuration shown by dashed line 109 in FIG. 4a may be used. This port configuration allows the ports in sleeve 40 to be relatively narrow while providing sufficient area for adequate gas volume, thus providing valve timing that is particularly advantageous for low speed operation. Because of the inwardly recessed convex arcuate side edges of the ports, the opening and closing action is much faster than if, for example, the intake and exhaust passages were circular and the boat 44 was circular.

If the engine is designed to operate on the diesel cycle, the sleeve 40 may be made of ceramic, thus reducing thermal conductivity and increasing thermal efficiency. To enhance the dispersion effect of lubricant during operation,
A V on the outer surface of sleeve 40 immediately “downstream” of port 44.
The shaped lubrication grooves are formed by fleas.

In Figures 3, 4a and 4b, a valve mechanism is indicated by the numeral 10 and is supported by a cylinder head 12 of an internal combustion engine. A portion of the cylinder block of the engine is designated by the number 14, and the top of one of the cylinders of the engine is designated by the number 16.

A vertical counterbore 18 is formed in the cylinder head 12, and a bearing shell 2 is inserted into the counterbore 18 from above.
0 is inserted. The shell 20 is forced into the counterbore 18 and eventually seats on a shoulder 22 at the lower end of the counterbore 18. Two boats 24,26 are formed in the bearing shell 20, and the shell 20 is pressed into the counterbore 18 in alignment with the boats 26 and 28, the fuel port 30 and the combustion gas outlet 32. The bearing shell 20 further has an opening 34 in its wall and a spark plug 36 (
A glow plug or fuel injector (in the case of a diesel engine) is inserted into the opening 34 through a threaded bore in the cylinder head 12 .

Bearing sleeve 20 has an outwardly directed peripheral flange 38 formed at its upper end that seats in cylinder head 12 about the mouth of counterbore 18 .

The valve sleeve 40 rotates within the bearing shell 20, the direction of rotation being indicated by the arrow in FIG. 4b. Valve sleeve 40 is also shown in detail in Figures 4a and 4b.

Valve sleeve 40 is generally cylindrical and has an inwardly directed flange 42 at one end thereof. A port 44 is provided in the cylindrical wall of the valve sleeve 40, and a slit 46 is also formed in the wall. This slit extends upwardly and downwardly from port 44 (particularly in
(see figure). Flange 42 is provided with a blind hole 48 which serves to receive a drive pin.

Valve sleeve 40 is rotated at half engine speed by a drive system generally designated 50 in FIG. The drive device 50 has a shaft 52 on which a helical gear is formed, which meshes with helical gear teeth 54 formed around a gear 56 . gear 56
is secured to the drive shaft, generally designated 60, by bolts 58, which are arranged coaxially with the sleeve 20.40. The drive shaft 60 consists of a shank 62, a disc-shaped portion 64, and a cylindrical extension piece 66 that is inserted into the upper end of the bearing sleeve 20.

A bearing carrier 68 is bolted to the cylinder head, a thrust bearing 70 is provided between the bearing carrier 68 and the disc-shaped portion 64 of the drive shaft 60, and a thrust bearing 70 is provided between the shank 62 and the bearing carrier 68. A journal bearing 72 is provided. These bearings are lubricated by pressurized oil, which allows excess heat to be carried away.

Disc-shaped portion 64 supports a drive pin (not shown) that enters blind hole 48 in valve sleeve 40 .

A bolt 58 extends beyond the extension piece 66 and into the valve sleeve 40. Within the sleeve 40 is a compression element 74 having a blind hole 76 into which the bolt 58 is threaded. Compression element 74 is of solid cylindrical shape, and its lower surface 78 is oblique to the axis of bolt 58.

As seen in FIG. 1, compression element 74 and extension piece 66 together form a peripheral groove into which flange 42 of valve sleeve 40 is received. The flange fits tightly into the groove and this structure functions as a seal.

The outer diameter of the valve sleeve 40 is slightly larger than the inner diameter of the bearing sleeve 20, and the slit 48 makes the overall diameter of the sleeve 40 small enough to allow the sleeve 40 to be inserted into the bearing sleeve 20. The nature of the sleeve 40 to open after being inserted into the sleeve 20 provides a sealing effect, which is enhanced when pressure is applied to the inside of the sleeve 40.

Sleeve 40 may be of steel, ceramic material, cast iron or nickel alloy.

When the valve is at operating temperature, the width of the slit 46 is approximately 0.
．． It is 1u. The disc-shaped portion 64 has a radial clearance of at most 0.1 mm within the sleeve 20. Thus, the actual area where gas can escape is the square hole (
0.1flX 0.1 m), totaling 0.01
This small opening moves around the inner surface of the sleeve 20 as the sleeve 40 rotates.

Sleeve 20.44 may be made of any suitable material, such as a self-lubricating anti-friction material.

As a lubricant, it is preferable to use a light oil containing colloidal graphite or the like dispersed therein. Ceramics could also be used due to their corrosion resistance. If the temperature is unusually high, it is better to use a low-friction, heat-resistant material such as a compound of graphite and molybdenum disulfide.

Spark plug, injector or glow plug 3
6 is protected from the effects of combustion except when the opening 34 overlaps this plug 36.

By replacing element 74 with one longer or shorter than shown, the compression ratio of the engine can be varied. Additionally, element 74 can be made of a material with high thermal conductivity and moved up shaft 60 to help remove excess heat from the combustion chamber.

Valve timing can be varied by adjusting between shaft 52 and gear 50.

This advances or delays the opening and closing of the intake ports and exhaust boats to the same extent.

In FIG. 5, the device has a partial port 80 and a secondary boat 82 below it. Element 74 of FIG. 1 has been replaced by a somewhat differently shaped element 74.1 which extends downwardly, partially beyond boat 80, so as to partially overlap secondary boat 82. Element 74 of FIG. - The next port is relatively small and its timing is such as to give optimal low speed efficiency. The secondary boat 82 is timed for full power operation at high speeds. - The next port 80 is connected to the partial barrel of a progressive carburetor with a two-handed tick.

The secondary boat 82 does not function at low speeds and low loads, but functions automatically as speed and load demands mean that the carburetor second barrel becomes active. - The secondary and secondary boats can also be used on the exhaust side, with only the secondary boat opening (e.g. by a butterfly valve controlled by engine manifold pressure or from some other suitable location) at increased speed and load. .

[Brief explanation of the drawing]

FIG. 1 is an isometric exploded view of a rotary valve assembly according to a preferred embodiment of the present invention, and FIG. 2 is a side view, partially in section, showing the rotary valve assembly installed within an engine head. 3 is a partial side view of a rotary valve assembly incorporated into an engine head in accordance with another embodiment of the present invention, and FIGS. 4a and 4b are respectively FIG. 3 is a side view and a plan view of the sealing sleeve used in the embodiment shown in the figures. FIG. 5 is a cross-sectional side view of another embodiment of a rotary valve assembly of the present invention shown partially installed within an engine head. 12... Engine head, 40... Sleeve, 30
...Intake passage, 32...Exhaust passage, 40.1...
Lower end, 16... Engine cylinder, 40.2... Upper end, 44... Boat, 50... Valve mechanism, 48...
,...driving formation. Procedural amendment (formality)

Claims (9)

[Claims] (1) having a sealing sleeve rotatably provided in the bore of the engine head housing the valve assembly;
The sleeve has a port that can periodically communicate with an intake passage and an exhaust passage arranged in the engine head during rotation of the sleeve, and a lower end of the sleeve communicates with the engine cylinder in which the piston reciprocates, and the sleeve The upper end is sealed and the sleeve is directly exposed to the combustion chamber formed within the sleeve, the sleeve being split lengthwise along its entire length by a slit aligned with the port and located at the upper end of the sleeve. A rotary valve assembly comprising a valve mechanism disposed within the head above the upper end of the sleeve and adapted to rotationally drive the sleeve by engaging a drive formation. 2. The rotary valve assembly of claim 1, further comprising a replaceable compression element adapted to be removably attached to the valve mechanism within the upper end of the bore of the sleeve. (3) The rotary valve assembly according to claim 2, wherein the valve element is removably attached to the valve mechanism by a coaxial bolt passing through the valve mechanism. (4) The drive formation at the upper end of the sleeve comprises one of a notch and a peg, and the valve mechanism has a cooperating formation that engages the drive formation. The rotary valve assembly described in (1). (5) The drive formation is angularly displaced from the leading edge of the sleeve adjacent the slit by an angle less than half the angular displacement from the trailing edge of the sleeve adjacent the slit. The rotary valve assembly described in (4). (6) The sleeve further has a low-speed operation port located above the port, and the port intermittently communicates with a low-speed operation intake passage and an exhaust passage provided in the engine head during rotation. A rotary valve assembly according to scope (1). (7) The valve mechanism includes a supported shaft, an integral disc below the shaft having a longitudinal thrust support upper surface terminating above the upper end of the sleeve, and a spring around the disc. A rotary valve assembly according to claim 1, comprising a loaded sealing ring assembly, and wherein the drive formation located on the underside of the shaft includes a gear in mesh with a gear on the drive shaft. (8) The port of the sleeve has a shape made of straight upper and lower edges and convex circular left and right side edges that bulge toward each other, and their curvature is similar to that of the intake passage of the head. The radius of curvature of the exhaust passage corresponds to the radius of curvature of the exhaust passage.
Rotary valve assembly described in item 1). (9) having a piston and a cylinder, and an engine head, the head having an intake passage and an exhaust passage communicating with the bore thereof, a lower end of the bore communicating with the cylinder, and a rotary valve assembly disposed on the wall of the bore; a split sealing sleeve in the bore spring loaded into sealing contact with the sleeve, a lower end of the sleeve open to the cylinder, a port in the sleeve aligned with the slit, and a valve mechanism located above the upper end of the sleeve. and a valve mechanism having a disc sealing the upper end of the sleeve and having a replaceable rotary valve element, the inwardly facing surfaces of the sleeve, disc and rotary valve element being connected to the upper end of the cylinder. with the combustion chamber closed and completely exposed to the combustion chamber, the valve mechanism is mutually
An internal combustion engine characterized in that it has a shaft connected to the upper surface of the disc and a valve drive train.