JPH0385307A - Exhaust system of internal combustion engine - Google Patents

Abstract

PURPOSE:To enhance the exhaust efficiency by interposing a spring between a piston and a connecting rod that connects it with a crank shaft and exhausting the exhaust gas remained in a cylinder with spring pressure during the exhaust cycle of the piston. CONSTITUTION:A rotary cylinder valve 3 in the form of cylinder is inserted into a cylinder block 1 freely rotatable, and its both end are supported by bearings 9 freely rotatable. And a piston main body 33 is fitted to the rotary cylinder valve 3 freely slidable, and this piston main 33 is mounted in the outside of a piston supporting body 32 freely movable through a coil spring 34. The piston supporting body 32 is connected to the other end of a connecting rod 30 whose one end is connected to a crank shaft 20 with a pin 32. And, an upper stopper 35 is integrally formed in the upper part of the inside of the piston main body 33, as well as a lower stopper 36 is fixed in the lower part, making the piston main body 33 free to relatively move against the piston supporting body 32 between the upper and lower stoppers 35, 36.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an exhaust system for an internal combustion engine. More specifically, the present invention relates to an exhaust system for an internal combustion engine that improves exhaust efficiency by incorporating a spring into a piston.

[Prior Art] An internal combustion engine with a reciprocating piston sucks a mixed gas of fuel and air into a cylinder chamber through an intake valve, and after explosive combustion occurs in the cylinder chamber, exhausts the combustion gas through an exhaust valve. The exhaust gas after explosive combustion is discharged from the exhaust valve by moving the piston within the cylinder.

On the other hand, valve mechanisms for air supply and exhaust are roughly divided into three types: mushroom valve mechanisms, sleeve valve mechanisms, and rotary valve mechanisms. Mushroom valve mechanisms are widely used in internal combustion engines and usually consist of a valve device and a drive device. The valve device includes a force/motor that controls the opening and closing of the valve, a transmission mechanism that transmits the movement of the cam, and an opening/closing mechanism that converts the movement into the opening and closing movement of the valve. This drive device is a mechanism that drives the camshaft in synchronization with the rotation of the crankshaft.

The mushroom valve devices currently in use are based on engine performance characteristics,
Several types of mechanisms are used commercially, depending on combustion chamber shape, serviceability, manufacturing cost, etc. They are broadly divided into the side valve type, which is mainly used in general-purpose engines, and the overhead valve type, which is used in automobile engines. Further, drive devices include gear drive, chain drive, and toothed belt drive.

In the sleeve valve mechanism, a sleeve is fitted onto the inner surface of a cylinder, and the sleeve is moved up and down or rotated to open and close intake and exhaust ports.

A rotary valve is a mechanism in which a rotor is provided in a part of an intake/exhaust passage or a combustion chamber, and the rotor is rotated to communicate with an intake/exhaust port. A rotary sleeve valve among sleeve valves opens and closes the intake and exhaust ports by rotating the sleeve.
It is described in Publication No. 5704, etc. Those using these sleeve valves have the following advantages: the valve hole area can be increased, so the ventilation efficiency for intake and exhaust is good, the valve mechanism is relatively simple, and there is little noise.

However, due to the difficulty of maintaining airtightness between the sleeve and cylinder block, the difficulty of lubricating the rotating contact surfaces, and friction loss, it is not currently put into practical use except for special purposes. The applicant is
An application was filed as Japanese Patent Application No. 134311/1983 to improve the drawbacks of conventional sleeve valve internal combustion engines. Furthermore, as an improvement of this invention, the exhaust efficiency was improved, and the patent application was filed as Japanese Patent Application No. 1-121485.

[Problems to be Solved by the Invention] In the exhaust cycle of a conventional internal combustion engine, there is a gap between the top dead center position of the piston and the upper surface of the cylinder head. Therefore, exhaust gas is not discharged by the volume of this gap. Therefore, the efficiency of the engine decreases by this amount. Furthermore, the above-mentioned sleeve valve type internal combustion engine is a past technology, and the seal technology level at the time of development had the problem that gas leak prevention and lubrication technology were incomplete and the compression ratio could not be increased very much. Furthermore, sleeve valve internal combustion engines are known to have good exhaust efficiency. However, it is not possible to completely exhaust exhaust gas. The patent application No. 1-121485 incorporates a piston supported by a spring in the cylinder head to improve exhaust efficiency. However, this type has a complicated structure.

An object of the present invention is to provide an exhaust system for an internal combustion engine in which the structure of the piston is improved in order to improve the exhaust efficiency of exhaust gas.

Another object of the present invention is to provide a structure of an exhaust system for a rotary sleeve valve internal combustion engine that improves intake and exhaust efficiency.

Still another object of the present invention is to provide an exhaust system for a rotary sleeve valve internal combustion engine in which the sealing effect of the rotary sleeve valve is improved.

[Means for solving the above problems] In order to solve the above problem, the following measures are taken.

The first means is that in a four-cycle reciprocating internal combustion engine in which a piston reciprocates within a cylinder by a crankshaft, a spring is interposed between the piston and a connecting rod connecting the crankshaft, and the piston The exhaust system for an internal combustion engine is characterized in that exhaust gas remaining in the cylinder during an exhaust cycle is discharged using the spring pressure.

The second means is, in a rotary sleeve valve internal combustion engine consisting of a cylinder block, a rotary cylinder valve, a piston, a crankshaft, etc., a. b. The rotary cylinder valve has an inlet hole and an exhaust hole; b. The rotary cylinder valve is rotatably supported within the cylinder block and has a central cylindrical space sealed at one end; and c. has an opening, and d. has a gear at one end of the rotary cylinder valve; e. the piston is slidably inserted into the rotary cylinder valve; f. the piston has a piston body; The rotary cylinder valve is provided on a piston support so as to be movable in the axial direction with a spring interposed therebetween; g. A crankshaft rotatably provided on a connecting rod connected to the piston support; h. The piston has a piston body provided on a piston support so as to be movable in the axial direction of the rotary cylinder valve with a spring interposed therebetween, and (i) a crank gear provided on the crankshaft and meshing with the gear. This is an exhaust system for internal combustion engines.

In the second means, it is more preferable that a seal ring is disposed annularly around the opening in order to seal the suction hole and the exhaust hole.

In the first means or the second means, it is more effective if a stopper is provided that prevents the piston body from moving beyond a certain distance against the spring.

In the first means or the second means, the rotary cylinder valve having a cylindrical space with one end sealed is replaced by a rotary cylinder valve having a cylindrical space with both ends open, and one end of the cylindrical space is open. A cylinder block may be inserted into the cylinder block with a gas seal, and the cylinder block may be fixed to the cylinder block.

[Operation] The starter rotates the crankshaft. When the piston moves toward bottom dead center, ie, away from the cylinder head, it draws in a gas mixture from the carburetor. The piston moves towards top dead center again, ie approaches the cylinder head and compresses the mixed gas.

At this time, the piston body moves back slightly due to the gas pressure of the compressed gas, compressing the spring.

Immediately before the piston reaches top dead center, the ignition plug ignites the compressed gas mixture, causing it to combust and expand after the piston reaches top dead center. The piston is pushed by the combustion gas and moves, driving the crankshaft. The piston body temporarily retreats due to the explosive force, but then returns to its original position. The piston rises again,
Exhaust air from the exhaust hole to the outside of the engine. Since there is almost no gap between the cylinder head and the piston body, most of the exhaust gas is exhausted. Repeat this operation thereafter.

[First example] Embodiments of the present invention will be described below with reference to the drawings.

What is shown in FIG. 1 is an embodiment in which a rotary cylinder valve 3 is provided. The cylinder block 1 is a cylindrical case with a hollow interior, and is made of a casting material that is a common engine material.

A crankcase 2 is provided at the lower end of the cylinder block 1. The crankcase 2 has a crankshaft 20 built therein. A cylindrical rotary cylinder valve 3 is rotatably inserted into the cylinder block 1.

A bevel gear 4 is integrally connected to one end of the rotary cylinder valve 3. The bevel gear 4 may be made separately from the rotary washer cylinder valve 3 and then assembled together after gear cutting. In the center of the rotary cylinder valve 3, there is provided an opening 5 which is oval when viewed from the inside and has a circular outlet (see FIG. 2). Rotary cylinder valve 3
A plurality of blades 6 are integrally provided in the radial direction on the outer periphery of the blade. The vanes 6 correspond to the vanes of a pump for circulating cooling water, and have a lead angle with respect to the rotational axis of the rotary cylinder valve 3.

The cylinder block 1 is provided with an intake hole 10 and an exhaust hole. The opening positions of the suction hole 10 and the exhaust hole are arranged in synchronization with the rotation of the opening 5 to match the suction, compression, expansion, and exhaust cycles of the engine. A cavity is formed between the rotary cylinder valve 3 and the cylinder block 1, and this cavity is a cooling chamber 8 for storing cooling water for cooling the rotary cylinder valve 3. This cooling chamber 8 is filled with cooling water to cool the outer periphery of the rotary cylinder valve 3.

Further, both ends of the rotary cylinder valve 3 are rotatably supported by bearings 9. For the bearing 9, a heat-resistant and corrosion-resistant material is selected, and a bearing that can withstand loads in the thrust direction is used. The crankshaft 20 has arm portions 22.22 at both ends with a bottle 21 in between, and the arm portion 22 further has a journal portion 23 eccentric to the bottle 21. The journal portion 23 is supported within the crankcase 2 by a bearing 24.

A crank gear 26 is provided at one end of the crankshaft 20, either integrally or separately. The crank gear 26 is a bevel gear and is engaged with the bevel gear 4 at one end of the rotary cylinder 3, so that it drives the rotary washer cylinder valve 3. The ratio of the number of teeth between the crank gear 26 and the bevel gear 4 is 1:
It is 2. The crank gear 26 rotates twice, while the bevel gear 4 rotates once.

One end of a connecting rod 30 is rotatably provided in the bin 21 of the crankshaft 20. A piston pin 31 is inserted into the other end of the connecting rod 30, and both ends of the piston pin 31 are fixed to a piston support 32. Piston support 3
A piston body 33 is provided on the outside of the rotary cylinder valve 3 so as to be movable in the axial direction of the rotary cylinder valve 3 via a coil spring 34. These piston pins 31. Piston support 32. A piston P is composed of the coil spring 34 and the piston body 33.

Further, an upper stopper 35 is integrally formed on the inner upper part of the piston body 33, and a lower stopper 36 is fixed to the lower part. This upper stopper 35 and lower stopper 3
6, the piston body 33 moves relative to the piston support 32. The groove on the outer periphery of the piston body 33 has two pressure rings 37, 37,
Oil rings 38 are fitted in each.

The diagrams shown in FIGS. 2(a), (b), (C), and (d) show the seal ring 40 of the opening 5 of the rotary cylinder valve 3.
Shows the structure and shape of. FIG. 2(a) is a cross-sectional view of the opening 5 of the rotary cylinder valve 3 taken in a direction perpendicular to the axis. FIG. 2(b) is a view seen from the direction of the arrow in FIG. 2(a), that is, from the inner hole. Figure 2 (c,)
is a view seen from the arrow C1 in FIG. 2(a), that is, from the outside. FIG. 2(d) is a sectional view taken along line dd in FIG. 2(c).

As can be understood from the figure, the opening 5 has an elongated inner hole of the rotary cylinder valve 3, and a circular outlet. When the inner bore is made circular, the opening 5 in the direction of movement of the piston becomes larger, resulting in a lower compression ratio. That is, if the pressure ring 37 of the piston is compressed beyond the opening 5, gas leakage will occur.

At the outer peripheral surface 19 of the rotary cylinder valve 3 and at the opening 5
A seal ring 40 is disposed at a circumferential position. The seal ring 40 has an annular shape and a cylindrical curved surface along the outer peripheral surface 19 of the rotary cylinder valve 3. A ring groove 41 is formed around the circumference of the opening 5 on the outer peripheral surface 19. A seal ring 40 is inserted into the ring groove 41. The ring groove 41 is the oil supply path 4
It communicates with 2.

On the other hand, the ring 71141 communicates with the oil discharge path 43. The oil supply path 42 and the oil discharge path 43 are provided with holes in the axial direction of the rotor washer cylinder valve 3 and communicate with the inside of the crankcase 2 . The crankcase 2 is filled with engine oil, and the crankshaft 20
is always accompanied by this. Engine oil is supplied to the oil intake port 44 by the rotation of the rotary cylinder valve 3.
Oil is supplied from the ring groove 41 (see FIG. 3), and excess oil filling the ring groove 41 is returned to the crankcase 2 through an oil discharge path 43.

Note that the oil intake port 44 is oriented toward the connection direction of the rotary cylinder valve 3 in order to easily take in oil (see Fig. 3).On the other hand, the seal ring 40 has a roughly rectangular cross section, and the outer periphery Oil through holes 45 are provided at predetermined intervals.The oil through holes 45 allow oil to seep out from the bottom of the ring groove 41 to the outer surface of the seal ring 40. The oil that comes out fills the oil groove provided on the surface of the seal ring 40.An oil groove is similarly provided on the bottom surface of the seal ring 40, and the oil is configured to flow between the oil through holes 45. .

Further, a wave-shaped leaf spring 46 is inserted between the bottom surface of the ring groove 41 and the bottom surface of the seal ring 40.
The seal ring 40 is always pushed outward by spring force. The seal ring 40 is pressed against the inner peripheral wall surface of the rotary cylinder valve 3 to maintain airtightness. cylinder block 1
A cylinder head 47 that is integrated with the rotary cylinder valve 3 is provided at the upper part of the rotary cylinder valve 3.

A plug screw hole 48 is provided in the center of the cylinder head 47. A plug storage hole 50 for storing a spark plug 49 is integrally formed in the center of the cylinder head 47. A spark plug 49 is inserted into the plug screw hole 48.
is the installation.

What is shown in FIG. 4 is a developed view showing the shapes of the suction hole 10 and the exhaust hole 15 provided in the cylinder block 1. As shown in FIG. The height below the exhaust hole 15 and the suction hole 10 (as shown in the figure) is approximately the same size as the diameter of the opening 5. Exhaust hole 15, suction hole 1
A semicircular protrusion 11 having the same diameter as the suction hole 10 protrudes from both sides in the circumferential direction of the suction hole 10 . A bridge portion 12 connects the semicircular protrusions 11 to each other. This bridge portion 12 prevents the seal ring 40 from falling off. First, the annular opening 5 communicates with the suction hole 10 over a semi-circumference, so suction efficiency is good.

The exhaust hole (not shown) has a similar shape and will not be described here.

An engine having a structure more than just a boat operates as follows. Either crankshaft 20 is rotationally driven by a starter (not shown). When the piston P moves toward the bottom dead center, the opening 5 and the suction hole 10 align, and the mixed gas is taken in from the opening 5. The mixed gas A is prepared using a known vaporizer (
(not shown). The amount of intake air in this intake cycle reaches its maximum amount in the middle of the overlap between the opening 5 and the intake hole 10, decreases as the overlap approaches the end, and the intake ends when the overlap ends (see Figure 4). Since the crank gear 26 of the crankshaft 20 is driving the rotary cylinder valve 3, the timing is adjusted so that the opening 5 and the suction hole 10 coincide.The piston P returns to the top dead center. That is, the mixed gas A is compressed. Due to this compression, the piston body 33 also moves slightly.

That is, the coil spring 34 is compressed (FIG. 5a).

At this time, the piston body 33 moves by a distance Mi until its upper stopper 35 touches the upper surface of the piston support 32. This moving distance is determined by a position that is balanced with the spring strength and compression pressure of the coil spring 34. therefore,
The piston body 33 has a distance Ni! It does not necessarily move by a distance, but only by a maximum distance of tixt. The spring pressure of the coil spring 34 is determined by the compression ratio determined from the efficiency of the engine. Immediately before the piston P reaches the top dead center, the opening 5 is located at the position of the spark plug 49, and the compressed mixed gas is ignited, and after the piston P reaches the top dead center, it is combusted and expanded.

The piston P is pushed by the combustion gas and moves, and the connecting rod 30
, drives the crankshaft 20 via the pin 21. At this time, at the same time, the piston body 33 is once compressed by the exploded and combusted gas and compresses the coil spring 34, but the piston body 33 returns to the position before compression. The exploded and combusted gas applies an averaged force to the piston P without pushing the piston P rapidly. The piston P rises again, the opening 5 and the exhaust hole 15 communicate with each other, and exhaust gas is exhausted from the exhaust hole 15 to the outside of the engine (FIG. 5b).

At this time, the lower stopper 36 of the piston body 33 is in contact with the piston support 32 due to the force of the coil spring 34. Since the gap between the cylinder head 47 and the piston body 33 during this exhaust process is extremely small, the exhaust gas is almost completely exhausted. Repeat this operation thereafter.

[Other Examples 1] The spark plug 49 of the above-mentioned example is attached to the cylinder head 4.
It was to be fixed at 7. The spark plug 49 does not necessarily have to be fixed to the cylinder head 47. The cross-sectional view shown in FIG. 6 is an example in which the cylinder block 1 is provided on the side surface thereof. The spark plug 49 is provided in the cylinder block 1 so that the spark plug 49 is located in the opening 5 of the rotary cylinder valve 3 during the compression stroke cycle. This has the effect of simplifying the engine head structure.

7(a) and 7(b) show other embodiments of the rotary cylinder valve 3. In FIG. Figure 7(a)
is a cross-sectional view of the rotor washer cylinder valve 3, and the seventh
FIG. 7(b) is a view seen from the direction of the arrow in FIG. 7(a). The seal ring 40 of the rotary cylinder valve 3 in the above embodiment was - in number. This embodiment is an example in which a double seal ring 40 is provided. Since the seal ring 40 is provided in duplicate, the sealing performance is good. Moreover, the oil supply path 42 of this embodiment is θ! with respect to the central axis of the rotary cylinder valve 3. It is tilted open.

The oil entering from the oil intake port 44 rises to the top due to the centrifugal force caused by the rotation of the rotary cylinder valve 3, and after supplying oil to the seal ring 40, the oil enters the oil discharge path 4.
It is discharged from 3. The oil discharge path 43 also forms an angle θ in the opposite direction to the axis of the rotary cylinder valve 3.
It is tilted by 2. Therefore, the centrifugal force causes the component force to tilt and discharge becomes smooth.

The ratio of the number of teeth between the crank gear 26 and the bevel gear 4 of the rotary cylinder valve 3 in the embodiment described above is 1:2. That is, the crank gear 26 rotates twice, while the bevel gear 4 rotates once. Since it is a 4-stroke engine, 4
The rotary cylinder valve 3 rotates once in each cycle. However, the intake hole 10, the exhaust hole, and the spark plug 4
If you install one on the opposite side 180 degrees instead of one, then 4
Even if the rotary cylinder valve 3 is rotated at a ratio of 1:1, a 4-cycle engine is still possible.

This may be realized by changing the fractional ratio of the gears of the rotary cylinder valve 3 and the bevel gear 4, or may be achieved by interposing a second gear to reduce the speed. Since the rotation speed of the rotary cylinder valve 3, which is difficult to seal with gas, is reduced, gas leakage can be reduced compared to the previous embodiment. Further, the rotational friction loss can also be reduced compared to that of the previous embodiment. Note that these techniques are publicly known techniques such as Japanese Patent No. 135563 (1945) and Japanese Utility Model Publication No. 5704/1983.

The seal ring 40 of the opening 5 of the rotary cylinder valve 3 of the above embodiment was provided on the rotary cylinder valve 3 itself. As can be understood from the above description, the seal ring 4
0 is for preventing gas leakage between the rotary cylinder block 3 and the cylinder block 1. The seal ring 40 may be provided in either the cylinder block 1 or the rotary cylinder valve 3 as long as it continuously fails this function. In addition, the shape and number of seal rings are as follows:
It is not limited to the above-mentioned embodiment, and any known material used in internal combustion engines may be used.

[Other Embodiment 2] This is a modification of the first embodiment shown in FIG. 8. The major feature of this embodiment is that the cylinder head 47
is fixed to the cylinder block 1 with bolts and divided into a rotary cylinder valve 3 and a cylinder head 47. An oil ring 51 and two pressure rings 52 are attached to the lower outer periphery of the cylinder head 47. This is to prevent compressed gas from leaking from this gap since the cylinder head 47 and rotary cylinder valve 3 rotate relative to each other.

All of the embodiments described above were applied to rotary sleeve valve internal combustion engines. However, as understood from the above description, it is clear that the piston described above can be applied to ordinary reciprocating type internal combustion engines that are currently widely used, and although not shown here, it is obvious that the piston described above can be applied to the conventional type internal combustion engine. Applies to internal combustion engines.

[Effects of the Invention] As detailed above, the present invention allows the piston body to move freely in the axial direction of the cylinder with a spring interposed therebetween.
It is installed in the piston body and has good exhaust efficiency during the exhaust cycle.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a first embodiment of an exhaust system for an internal combustion engine with a rotary sleeve valve, and FIGS. 2(a), (b), and (C)
), (d) is a diagram showing the arrangement of the gas seal mechanism at the opening,
Fig. 3 is a sectional view of the oil intake port of the rotary cylinder valve, Fig. 4 is a developed view showing the shapes of the exhaust hole and suction hole, and Fig. 5
Figures (a> and (b) are state diagrams showing the action of exhaust and compression in this embodiment, Figure 6 is a sectional view showing another embodiment in which the spark plug is provided on the side, Figure 7 (a), (b) is a diagram showing another embodiment of the rotary cylinder valve, and FIG. 8 is a sectional view showing a second embodiment of the exhaust system for a rotary sleeve valve internal combustion engine. 1... Cylinder block, 2 ···Crankcase,
3... Rotary cylinder valve, 4... Bevel gear, 5... Opening, 6... Vane, 8... Cooling chamber, 1
0... Suction hole, 15... Exhaust hole, 20... Crankshaft, 26... Crank gear, 30... Connecting rod, 3
1... Piston pin, 32... Piston support, 3
3...Piston body, 5...Upper stopper 36...Lower stopper 47...Cylinder head

Claims (1)

[Claims] 1. In a four-cycle reciprocating internal combustion engine of the type in which a piston reciprocates within a cylinder by a crankshaft, a spring is interposed between the piston and a connecting rod connecting the crankshaft, and the An exhaust system for an internal combustion engine, characterized in that exhaust gas remaining in the cylinder during a piston exhaust cycle is exhausted by the spring pressure. 2. Cylinder block, rotary cylinder valve,
In a rotary sleeve valve internal combustion engine consisting of a piston, a crankshaft, etc., a. the cylinder block has an intake hole and an exhaust hole for sucking in and discharging mixed gas and exhaust gas; b. the rotary cylinder The valve is rotatably supported within the cylinder block and has a cylindrical space in the center with one end sealed, c) an opening on the outer periphery of the rotary cylinder valve, and d) one end of the rotary cylinder valve. has a gear; e. the piston is slidably inserted into the rotary cylinder valve; and f. the piston is configured to move the piston body in the axial direction of the rotary cylinder valve with a spring interposed therebetween. g. a crankshaft rotatably provided on a connecting rod connected to the piston support; and h. the piston is configured to rotate the piston body in the axial direction of the rotary cylinder valve. An exhaust system for an internal combustion engine, characterized in that it is movably provided on a piston support with a spring interposed therebetween, and further comprises: (i) a crank gear that is provided on the crankshaft and meshes with the gear; 3. The exhaust system for an internal combustion engine according to claim 2, further comprising a seal ring disposed annularly around the opening to seal the intake hole and the exhaust hole. 4. The exhaust system for an internal combustion engine according to claim 2 or 3, further comprising a stopper that prevents the piston body from moving beyond a certain distance against the spring. 5. In one item selected from claims 2, 3, and 4, the rotary cylinder valve has a cylindrical space with both ends open, instead of the rotary cylinder valve having a cylindrical space with one end sealed, 1. An exhaust system for an internal combustion engine, characterized in that a cylinder block is inserted into one open end of a cylindrical space with a gas seal, and the cylinder block is fixed to the cylinder block.