JPS63105214A - Sealing structure of rotational open/close type spherical intake/exhaust valve for internal combustion engine - Google Patents

Abstract

PURPOSE:To improve sealability by inclining, toward the outer perimeter edge from the inner perimeter edge and in a direction approaching an intake or exhaust valve, a ring-shaped elastic material which press-contacts a ring-shaped sealing material to the intake or exhaust valve. CONSTITUTION:A ring-shaped sealing member 19 and a ring-shaped elastic material 18 are insert-equipped between the wall portion of an intake or exhaust passage and an intake or exhaust valve 13. The end-surfaces 18a, 18b of the elastic material 18 are made to incline toward the outer perimeter edge from the inner perimeter edge and in a direction approaching the intake or exhaust valve 13. As a result, the sealing material 19 can be press-contacted to the intake or exhaust valve 13 by means of spring force arising from the elastic material 18's tendency toward outward expansion, and sealability can be heightened.

Description

[Detailed Description of the Invention] L1 Upper Summer and Yu±1 The present invention provides a reciprocating four-cycle internal combustion engine that can rotate around an axis perpendicular to the intake and exhaust passages without using mushroom-shaped intake and exhaust valves. The present invention relates to a seal structure for an intake/exhaust system in which an intake/exhaust valve is interposed in an intake/exhaust passage, and the intake/exhaust passage is opened/closed by rotation of the intake/exhaust valve.

In the mushroom-shaped suction and refueling valve used in normal internal combustion engines, the valve passage area increases as the valve diameter and valve lift increase, but the valve diameter is limited by the cylinder radius, and the valve lift increases. Since it is limited by the impact caused by the reciprocating movement of the valve, it is difficult to widen the valve passage and greatly increase the suction efficiency in high-speed operating conditions.

In order to improve this, there have been 17 conventional systems in which intake and exhaust valves are rotatably interposed in one direction or in a reciprocating direction about an axis perpendicular to the intake ↑A air passage. Since the intake and exhaust valves are always in relative sliding contact with the walls of the intake and exhaust passages, the walls of the intake and exhaust passages and the intake and exhaust valves are not connected to each other, as described in Utility Model Application Publication No. 55-1953@. A sealing structure is required.

1 In the seal structure described in Japanese Utility Model Application Publication No. 55-1953, as shown in FIGS. 1 and 2, the intake and exhaust valves 0
A resilient member 04 is interposed between the sealing material 02 that contacts the combustion chamber 1 and the intake/exhaust valve passage wall 03a near the combustion chamber, and this resilient member 04
The sealing material 02 was brought into pressure contact with the intake/exhaust valve 01 by the spring force and combustion gas pressure, thereby sealing the intake/exhaust valve passage wall 03 and the intake/exhaust valve 01.

However, in an intake/exhaust system equipped with an E-shaped intake/exhaust valve,
Since the ear-shaped intake and exhaust valves can protrude freely toward the combustion chamber, when the intake and exhaust valves are closed, the intake and exhaust passages are sealed by the ear-shaped intake and exhaust valves, creating a space communicating above the combustion chamber. However, in the intake/exhaust system equipped with the rotationally open type intake/exhaust valve 01 shown in FIGS. Between 05 and 05, there is an intake and exhaust passage 06 surrounded by a sealing material and an intake/exhaust valve passage wall that supports the sealing material, and this intake and exhaust passage 06 space near the combustion chamber 05 closes the combustion chamber 05 near the spark plug. In order to maintain a predetermined compression ratio due to the reduced space, the sum of the intake and exhaust passages near the combustion chamber and the combustion chamber space near the ignition plug must be constant), making it difficult to obtain a good combustion state.

In order to solve this problem, as shown in FIG. 3, if the intake and exhaust passage wall parts 03a near the combustion chamber are made thinner, the intake and exhaust passage wall parts 03a will be easily chipped, and as a result, the set load of the elastic member will be reduced. It becomes small and sufficient sealing performance cannot be obtained.

[1] The present invention relates to an improvement in the sealing structure of a rotary opening/closing type spherical intake/exhaust valve that overcomes the above-mentioned difficulties. In an intake/exhaust system in which the intake/exhaust passage is opened/closed by rotation of the spherical intake/exhaust valve, at least a ring-shaped elastic material that presses a ring-top sealing material against the intake/exhaust valve is opposite to the intake/exhaust valve. the side end surface,
The ring-shaped elastic material is inclined in a direction approaching the intake and exhaust valve from the inner circumference toward the outer circumference, and the inclined end surface of the ring-shaped elastic material is attached to an intake and exhaust passage opening wall near the combustion chamber that opens toward the combustion chamber of the internal combustion engine. By supporting the ring-shaped elastic material closely, the spring force of the ring-shaped resilient material expanding outward causes the seal material to come into pressure contact with the intake/exhaust valve along its inclined end surface, thereby providing sufficient sealing performance. Moreover, the new surface shape of the opening wall of the intake and exhaust passage near the combustion chamber is formed into a tapered shape to ensure a sufficient thickness of the resilient material support base of the opening wall of the intake and exhaust passage. However, the intake/exhaust passage space surrounded by the sealing material and the opening wall of the intake/exhaust passage near the combustion chamber can be narrowed.

Friend if An embodiment of the present invention illustrated in FIGS. 4 to 9 will be described below.

An engine 1 mounted on a motorcycle (not shown) is 1
A four-cylinder gasoline engine, a crankshaft 6 is rotatably supported in a crankcase 2 of an engine 1, and a 1F! 1M￥F for free movement
The piston 7 is connected to the crankshaft 6 via a connecting rod 8, and the reciprocating movement of the piston 7 causes the crankshaft 6 to rotate in the forward direction.

Furthermore, two intake passages 9 and two exhaust passages 10 are formed in the cylinder head 4 and head cover 5, respectively, and a separate carburetor 11 is connected to each intake passage 9, and a j1 trachea is connected to each exhaust passage 10. 12 are connected.

A spherical intake valve 13 and a spherical exhaust valve 14 are respectively fitted into the intake passage 9 and the exhaust passage 10 so as to be swingable about a direction perpendicular to the longitudinal direction thereof. An upper sealing material 15 is interposed between the exhaust valve 14 and the opening wall 4a of the cylinder head 4 adjacent to the intake boat 16 and the exhaust boat 17, and the spherical intake valve 13 and the spherical exhaust valve 14. A ring-shaped elastic material 18 and a lower seal material 19 are interposed in the ring-shaped elastic material 18, and the cross-sectional shape of the ring-shaped elastic material 18 has a trapezoidal shape in which the outer circumferential side is thinner than the inner circumferential side. Resilient material contact surface 19a of No. 19 and resilient material contact surface 4b of opening wall portion 4a
It is formed in an inclined shape so that it can come into close contact with the upper and lower end surfaces 18a and 18b of the ring-shaped elastic material 18.

In addition, a notch 13b oriented in the radial direction is formed on the opposing end surface of each of the left and right spherical intake valves 13, and the adjacent one
A base portion 20a of the connecting piece 20 that engages with the pair of notches 13b is formed, and a top portion 20b of the connecting piece 20 is formed on the connecting disk 21.
are mutually orthogonal and 'FII? ! , a cross groove 21a is formed so that the base portion 20a of the connecting piece 20 is engaged with the notch 13b of a pair of adjacent spherical intake valves 13, and the top portions 20b of the connecting piece 20 are orthogonal to each other. If the cross grooves 21a of the connecting disk 21 are engaged with each other in this state, a misaligned shaft joint is formed, and even if the rotation centers of the adjacent pair of spherical intake valves 13 are shifted from each other, one of the spherical Rotational torque is smoothly transmitted from the intake valve 13 to the other spherical intake valve 13 (the spherical exhaust valve 14 is also configured with an offset shaft joint similar to the spherical intake valve 13).

Furthermore, protrusions 13c and 14c are formed on the other end face of one spherical intake valve 13 and the other end face of the spherical exhaust valve 14, and protrusions 23a and 24a are also formed on the inner end face of the valve drive shaft 23, 24, and the connection Is there a cross on the connecting disk 22 like the disk 21? l
522a is formed, and the protrusions 23a and 24a are fitted into the cross groove 22a of the connecting disk 22 in a state where they are perpendicular to each other, so that the spherical intake valve 131 and the spherical agonistic valve 14
2 to the valve drive @23.24, which valve part l
An intake valve driven gear p25 and an exhaust valve driven gear 26 are integrally fitted to the J shafts 23 and 24.

Furthermore, a crank gear 727 is integrally fitted to the crankshaft 6, and the crank gear r27 is connected to the crank case 2.
The idle gear 29, which is integrated with the idle gear 28, is connected to a pair of cam gears 31 and 32 via a drive gear 30. , this cam gear 31.3
Cams 33, 34 are integrally attached to each of 2, and when the crankshaft 6 rotates together with the crank gear 27 in the direction B, the idle gear 28, 29 rotates in the B direction, the drive gear 30 in the direction B, the cam gears 31, 32, cam 3
3.34 is designed to be rotationally driven in the B direction.

Moreover, a cam follower 35.36 is pivotally supported on the cylinder head 4, and the cam follower 35.36 swings in contact with the cam 33.34.
, an exhaust valve drive gear 38 are integrally formed, and the intake valve drive gear 37 and the exhaust valve drive gear 38 are meshed with the intake valve driven gear 25 and the exhaust valve driven gear 26, respectively.

Further, a return spring 39 is interposed between the head cover 5 and the cam followers 35.36, and the spring force of the return spring 39 causes the cam followers 35.3 to
6 is in constant pressure contact with the cams 33 and 34.

Furthermore, protrusions 7a and 7b are formed at the top of the piston 7 so as to protrude into the intake boat 16 and the exhaust boat 17.

Since the embodiment shown in FIGS. 4 to 9 is configured as described above, when the crankshaft 6 is rotated in the direction toward by the starter motor (not shown), the cam gears 31, 32 and the cams 33, 34 are rotated. crankshaft 6
This cam 33 is rotated in eight directions at half the rotation speed of
．． The cam followers 35 and 36 in contact with 34 are driven to swing up and down once every 1H when the crankshaft 6 rotates twice.
The intake valve driven gear 25, the exhaust valve driven gear 26, the valve drive shafts 23, 24, the spherical intake valve 13, and the spherical exhaust valve 14 are rotated by 90 degrees each time, and the intake passage 9, 10 is opened and closed, and thus the required 4: intake, compression, expansion, exhaust
The stroke is repeated, and the engine 1 is brought into operation.

Further, since the spherical intake valve 13 and the spherical exhaust valve 14 are subjected to intermittent rocking motion, vibrations unlike the one-piece intake and exhaust valves are less likely to occur.

Furthermore, the lower seal material 19 includes a ring-shaped instant material 1.
The upward force generated by the spring force that tends to expand in the outer radial direction of the ring 8 and the combustion gas pressure acting on the inner periphery of the ring-shaped elastic member 18 moves, and this upward force causes the lower seal member 19 to close the spherical intake valve. 13. Pressed against the spherical exhaust valve 14, and the pressing force also acts on the upper sealing material 15, the spherical intake valve 13, and the spherical exhaust valve 14, so that the intake passage 9, the exhaust passage 10, the spherical intake valve 13, and the spherical exhaust valve High airtightness with valve 14.

Moreover, the cross-sectional shape of the ring-shaped elastic material 18 is trapezoidal so that the outer circumferential side is thinner than the inner circumferential side.
In addition, the resilient material contacting surface 4b of the opening wall portion 4a is inclined upward in a direction away from the center of the intake boat 1G and the exhaust boat 17 so that it can come into close contact with the lower end surface 18b of the ring-shaped resilient material 18. Therefore, the proximal end 4C of the opening wall 4a is thicker than the distal end 4d. Therefore, even if the cylinder head 4 is made of aluminum, the proximal end 4G is strong and difficult to break off.

As a result, the opening wall 4a can be made thinner as a whole in a state where it can sufficiently withstand the set load of the ring-shaped elastic material 18 that is about to expand. Since the space near the intake boat 16 and exhaust boat 17 at the fulcrum of the piston 7 can be closed off, the combustion chamber space 41 is concentrated near the spark plug 40 at the fulcrum of the piston 7 to maintain an appropriate combustion state. can be held.

Furthermore, since the two pairs of spherical intake valves 13 and spherical exhaust valves 14 are each connected to each other via a misaligned shaft joint made of 3U joints 20 and 21, each spherical intake valve 13 and spherical exhaust valve 14 have an upper The sealing material 15 and lower sealing material 18 can be brought into close contact with each other without any difficulty.

As described above, in the present invention, since the cross-sectional shape of the opening wall of the intake and exhaust passage near the combustion chamber can be formed into a tapered shape, the thickness of the elastic material support base of the opening wall of the intake and exhaust passage can be reduced. It is possible to narrow the intake/exhaust passage space surrounded by the sealing material and the intake/exhaust passage opening wall near the combustion chamber while ensuring a sufficient amount;
As a result, it is possible to maintain a good combustion condition and improve durability.

[Brief explanation of the drawing]

1 to 3 are enlarged cross-sectional views of main parts showing the seal structure of a conventional rotary open/close type intake and exhaust valve for an internal V5 engine, and FIG. 4 is an enlarged cross-sectional view of a rotary open/close type spherical intake/exhaust valve according to the present invention. 5 is a vertical left side view of a 1-a-fi 4-cycle gasoline engine for motorcycles equipped with an embodiment of a seal structure, FIG. 5 is a vertical right side view of the main parts of the engine, and FIG.
Figure 7 is an exploded perspective view of the main part, Figure 8 is an enlarged longitudinal sectional view of the main part of Figure 4, and Figure 9 shows the piston slightly below the fulcrum. Enlargement of the main part of the descending state! FIG. 1...Engine, 2...Crankcase, 3...
Cylinder block, 4... Cylinder head, 5...
Head cover, 6... crank shirt], 7...
Piston, 8... Connecting rod, 9... Intake passage, 10... Exhaust passage, 11... Carburetor, 12... Exhaust pipe, 13... Spherical intake valve, 14...
・Spherical exhaust valve, 15... Upper seal material, 16...
・Intake boat, 17... Exhaust boat, 18... Ring-shaped elastic material, 19... Lower seal material, 20.21.2
2... Connection piece, 23.24... Valve drive shaft, 25...
・Intake valve driven gear, 2G...Exhaust valve driven gear, 27...Crank gear, 28, 29...Idle gear, 30...Drive gear, 31° 32...Cam gear, 33.34... Cam, 35.36...Cam follower, 37...Intake valve drive gear, 38...
Exhaust valve drive gear, 39... return spring,
40...Spark plug, 41...Combustion chamber space.

Claims (1)

[Claims] In an intake/exhaust system in which a spherical intake/exhaust valve is rotatably interposed in an intake/exhaust passage of an internal combustion engine, and the intake/exhaust passage is opened/closed by rotation of the spherical intake/exhaust valve, a ring-shaped intake/exhaust valve is attached to the intake/exhaust valve. At least the end surface of the ring-shaped elastic material that presses the sealing material on the side opposite to the intake/exhaust valve is inclined from the inner circumferential edge toward the outer circumferential edge in a direction approaching the intake/exhaust valve, and the ring-shaped elastic material is inclined. A seal structure for a rotary open/close type spherical intake/exhaust valve for an internal combustion engine, characterized in that an end face is closely supported flush with an opening wall of an intake/exhaust passage near the combustion chamber that opens toward the combustion chamber of the internal combustion engine.