JP2007211664A - Air intake and exhaust device of internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform more reliable scavenging near the top dead center of an exhaust stroke in a high-rotation region of an internal combustion engine. <P>SOLUTION: An air intake valve 43 is constructed by an outer valve 54 and an inner valve 55 movably inserted in an inner valve hole of the outer valve 54. An exhaust valve 46 is constructed by an outer valve 65 and an inner valve 66 movably inserted in an inside valve hole of the outer valve 65. An inside passage 60 opened and closed by the inner valves 55, 66 is formed in the outer valves 54, 65, and at least in scavenging, an non-overlap state of closing the respective outer valves 54, 65 of air intake/exhaust valves 43, 46 at the same time is caused by a first cam and a second cam for controlling the opening and closing of the outer valves 54, 65 and the inner valves 55, 66, and also an overlap state of opening the respective inner valves 55, 66 of the air intake/exhaust valves 43, 46 at the same time is caused by the same. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an improvement of an intake / exhaust device for an internal combustion engine.

As a conventional internal combustion engine, an engine having a larger area for generating squish is known (for example, see Patent Document 1).
In addition, as a conventional intake / exhaust device for an internal combustion engine, the intake / exhaust valve is non-overlapping near the top dead center at the end of the exhaust stroke (see, for example, Patent Document 2), and the intake / exhaust valve has a double structure. (For example, refer to Patent Document 3).
JP-A-2005-23831 JP 2000-73803 A JP-A-7-77018

  In FIG. 1 to FIG. 3 of Patent Document 1, intake valves 4 and 5 are provided in the cylinder head 1 a, opposed to one intake valve 4, a concave space portion 7 a is formed in a part of the top of the piston 7, It is described that a squish area 14 having a large area is formed between the top of the piston 7a excluding the concave space 7a and the cylinder head 1a. Such a large squish area 14 facilitates squish and improves combustion.

  3 and 4 of Patent Document 2 show that the exhaust valve and the intake valve are overlapped by closing the exhaust valve after the intake TDC and opening the intake valve before the intake TDC when the engine is under a heavy load. Further, FIGS. 5 and 6 of Patent Document 2 describe that the exhaust valve and the intake valve are brought into a non-overlapping state by closing the exhaust valve before the intake TDC when the engine is under a low load. Has been.

In FIG. 1 and FIG. 4 of Patent Document 3, the intake valve is composed of an outer valve and an inner valve that is movably inserted into the outer valve, and the port 4 is opened and closed by the outer valve, and the outer valve is the outer valve. It describes that the vent 23A provided in the valve is opened and closed.
The outer valve is opened and closed by the rocker arm 10A, and the inner valve is opened when the combustion chamber reaches a predetermined negative pressure. The exhaust valve has the same structure as the intake valve.

  Although the exhaust valve is not described in Patent Document 1, normally, the exhaust valve and the intake valve are in an overlapping state in which the exhaust valve and the intake valve are opened at the same time in the vicinity of the top dead center in the exhaust stroke. In this overlap state, a scavenging action is performed in which the fresh air sucked in instantaneously drives out the residual gas. However, as the engine speed increases, a sufficient scavenging action is not performed due to the inertia of the intake and exhaust gas. The scavenging state is expressed as the mass of fresh air remaining in the cylinder before combustion relative to the mass of fresh air supplied into the cylinder, that is, the supply efficiency, and directly affects the engine performance. It is more desirable to perform sufficient scavenging while expanding.

In Patent Document 2, the exhaust valve and the intake valve are overlapped when the load is high, but since the overlap amount is small, it is difficult to perform reliable scavenging at the time of high rotation.
Therefore, it is conceivable to increase the valve lift by increasing the overlap amount, but there is a risk of interference between the intake / exhaust valve and the piston top, and a valve recess is required at the piston top. Therefore, the area of the squish area is reduced.

In Patent Document 3, the opening and closing timings of the outer valve and the inner valve of the intake valve are not described, and the overlap state of the intake and exhaust valves near the top dead center of the exhaust stroke is not clear. A more reliable scavenging near the dead center is desired.
An object of the present invention is to perform more reliable scavenging in the vicinity of the top dead center of the exhaust stroke in the high rotation range of the internal combustion engine and to enlarge the squish area.

  The invention according to claim 1 is an internal combustion engine in which an intake / exhaust valve that opens and closes an intake / exhaust port that communicates with a combustion chamber is provided in a cylinder head, and an outer side that has an inner valve hole that penetrates the intake / exhaust valve in the axial direction. This is a double valve consisting of a valve and an inner valve that is movably inserted into the inner valve hole. The outer valve is connected to the intake and exhaust ports and the combustion chamber, and an inner passage that is opened and closed by the inner valve is formed. The valve timing control device for controlling the opening and closing of the outer valve and the inner valve of the intake and exhaust valve, and by this valve timing control device, at the time of scavenging, the outer valves of the intake and exhaust valves are simultaneously closed, and the intake and exhaust valves are closed. It is characterized by making it the overlapping state which opens each inner valve | bulb simultaneously.

  As an action, at least during scavenging, at least near the top dead center of the exhaust stroke, the outer valve of the exhaust valve and the outer valve of the intake valve are made non-overlapping, and the inner valve of the exhaust valve and the inner valve of the intake valve overlap. Put it in a state. Thus, by increasing the lift amount of the inner valve having a small outer diameter, the valve opening area is increased, and interference between the inner valve and the piston top is prevented.

  The invention according to claim 2 is an internal combustion engine in which an intake / exhaust valve for opening and closing an intake / exhaust port leading to a combustion chamber is provided in a cylinder head, and an outer side with an inner valve hole penetrating the intake / exhaust valve in the axial direction is provided. This is a double valve consisting of a valve and an inner valve that is movably inserted into the inner valve hole. The outer valve communicates the intake and exhaust ports and the combustion chamber and forms an inner passage that is opened and closed by the inner valve. A valve timing control device that controls the opening and closing of the outer valve and the inner valve is provided. The valve timing control device opens the outer valve and the inner valve of the exhaust valve in the exhaust stroke, and opens the outer valve and the inner valve of the intake valve in the intake stroke. It is characterized by opening each.

  As an action, by opening each outer valve and each inner valve of the exhaust valve in the exhaust stroke and opening each outer valve and each inner valve of the intake valve in the intake stroke, the opening area of the outer valve and the inner valve This increases the opening area of the intake / exhaust valve.

  In the invention according to claim 1, the intake / exhaust valve is a double valve comprising an outer valve having an inner valve hole penetrating in the axial direction and an inner valve movably inserted into the inner valve hole. The valve timing control device for communicating the intake and exhaust ports and the combustion chamber and forming an inner passage that is opened and closed by the inner valve and controlling the opening and closing of the outer valve and the inner valve is provided by the valve timing control device. At least during scavenging, the outer valves of the intake / exhaust valves are closed simultaneously, and the inner valves of the intake / exhaust valves are opened simultaneously. The squish area can be increased by eliminating the valve recess on the piston top surface. Rukoto can, it is possible to improve the engine output performance and combustion efficiency.

  In the invention according to claim 2, the intake / exhaust valve is a double valve comprising an outer valve having an inner valve hole penetrating in the axial direction and an inner valve movably inserted into the inner valve hole. The intake / exhaust port and the combustion chamber communicate with each other, and an inner passage that is opened and closed by an inner valve is formed. The outer valve and a valve timing control device that controls the opening and closing of the inner valve are provided. Open the outer valve and the inner valve of the exhaust valve respectively, and open the outer valve and the inner valve of the intake valve in the intake stroke, respectively, so that the effective opening area of the intake and exhaust valves can be increased and the intake air amount can be increased. And engine output can be improved.

The best mode for carrying out the present invention will be described below with reference to the accompanying drawings. The drawings are viewed in the direction of the reference numerals.
FIG. 1 is a cross-sectional view (first embodiment) of an internal combustion engine provided with an intake / exhaust device according to the present invention. The internal combustion engine 10 includes, for example, a left cylinder portion 12 as a first cylinder and a second cylinder as a second cylinder. The OHV 2-cylinder horizontally opposed type is composed of a right cylinder portion 14 and a crankshaft 16 and a camshaft 17 are rotatably mounted between the left cylinder portion 12 and the right cylinder portion 14.
The left cylinder portion 12 and the right cylinder portion 14 have the same basic structure, and only the right cylinder portion 14 will be described below.

  The right cylinder portion 14 includes a cylinder block 21, a cylinder head 22 attached to an end portion of the cylinder block 21, and a head cover 23 that covers an opening on one end portion side of the cylinder head 22.

  The cylinder block 21 is made of an aluminum alloy, and is a member in which a cylinder liner 26 made of cast iron is cast into the hole 25. Reference numeral 27 denotes a water jacket formed between the hole 25 and the cylinder liner 26, and 28 denotes a cylinder axis passing through the center of the cylinder liner 26.

The crankshaft 16 is a member in which the large end portion 33 a of the connecting rod 33 is connected to the crankpin 31 via a bearing 32.
The connecting rod 33 is a member in which the inner coupling portion 34a of the piston 34 is coupled to the small end portion 33b. The small end portion 33b and the inner coupling portion 34a constitute a spherical plain bearing 36.
The piston 34 is a member that is movably inserted into the cylinder liner 26.

The cylinder head 22 has a concave combustion chamber wall 38a that forms a combustion chamber 40 with the head main body 38 and the top surface 34b of the piston 34, and outer walls 38b and 38c (only one symbol 38c is shown from the combustion chamber wall 38a. An intake port 38d and an exhaust port 38e, respectively, and an intake valve 43 attached to the head body 38 through a valve guide 42 so as to reciprocate in order to open and close the outlet of the intake port 38d to the combustion chamber 40; In order to open and close the inlet of the exhaust port 38e from the combustion chamber 40, an exhaust valve 46 attached to the head main body 38 through a valve guide 44 so as to reciprocate is provided. Note that 45 is an intake side valve seat, 47 is an exhaust side valve seat, 49 is an intake pipe, and 50 is an exhaust pipe.
The combustion chamber wall 38a, the outer walls 38b and 38c, the intake port 38d and the exhaust port 38e described above are formed in the head body 38.

  The intake valve 43 reciprocates by an intake side valve mechanism 48, and the exhaust valve 46 is a member that reciprocates by an exhaust side valve mechanism (not shown). The basic structure of the exhaust side valve mechanism is the same as that of the intake side valve mechanism 48, and a description thereof will be omitted.

FIG. 2 is a diagram (first embodiment) showing the arrangement of intake and exhaust valves according to the present invention, as viewed from the direction in which the cylinder axis 28 shown in FIG. 1 (the cylinder axis 28 is indicated by a black circle in this figure). It is a figure. (FIG. 1 is a sectional view taken along line 1-1 in this figure.)
The pair of intake valves 43, 43 and the exhaust valve 46 are arranged radially so that the axis lines 51, 51, 52 of each valve pass through the cylinder axis line 28.

The intake valve 43 includes an outer valve 54 and an inner valve 55 movably inserted inside the outer valve 54.
The outer valve 54 includes a shaft portion 57 and an umbrella portion 58 provided integrally at the tip of the shaft portion 57, and a plurality of vent holes 59 are opened in the umbrella portion 58. The umbrella portion 58 is a portion whose outer shape is non-circular.
The inner bulb 55 includes a shaft portion 62 and an umbrella portion 63 provided integrally at the tip of the shaft portion 62, and the outer shape of the umbrella portion 63 is non-circular.

The exhaust valve 46 includes an outer valve 65 and an inner valve 66 movably inserted inside the outer valve 65.
The outer valve 65 includes a shaft portion 68 and an umbrella portion 71 provided integrally at the tip of the shaft portion 68, and a plurality of vent holes 72 are opened in the umbrella portion 71. The umbrella portion 71 is a portion whose outer shape is non-circular.
The inner bulb 66 includes a shaft portion 74 and an umbrella portion 75 provided integrally at the tip of the shaft portion 74, and the outer shape of the umbrella portion 75 is non-circular.

FIG. 3 is a cross-sectional view (first embodiment) showing an intake valve and an intake side valve mechanism according to the present invention.
The outer valve 54 of the intake valve 43 includes an inner valve hole 54a through which the shaft portion 57 is inserted in order to insert the inner valve 55 movably, an umbrella portion storage portion 54b for storing the umbrella portion 63 of the inner valve 55, A plurality of vents 59 opened to communicate the upper surface 58a side of the umbrella part 58 and the umbrella part storage part 54b are formed, and two flanges 71 and 72 are attached to the shaft part 57 at a distance. The above-described umbrella portion storage portion 54 b and the plurality of vent holes 59 constitute an inner passage 60 that is opened and closed by the inner valve 55. In addition, 54c is a valve face formed on the outer periphery of the umbrella portion 58 of the outer valve 54 in order to closely contact the valve seat 45 (see FIG. 1), and 54d is a valve side seat formed on the bottom surface of the umbrella portion 58 of the outer valve 54. is there.

  The inner valve 55 has two flanges 73 and 74 attached to the shaft portion 62 at a distance. Reference numeral 55a denotes a valve face formed on the outer periphery of the umbrella portion 63 of the inner valve 55 so as to be in close contact with the valve side seat 54d of the outer valve 54.

  The intake-side valve mechanism 48 includes a cam-side rocker shaft 81 attached to the cylinder block 21 and a cam-side rocker shaft 81 that is swingably attached to the cam-side rocker shaft 81 to be driven by a first cam 82 provided on the camshaft 17. 1 rocker arm 83, a cylindrical first push rod 84 having one end swingably connected to the cam side first rocker arm 83, a valve side rocker shaft 86 attached to the head body 38, and the first push rod 84 A valve-side first rocker arm 87 that is swingably connected to the end and is swingably attached to the valve-side rocker shaft 86 and has a distal end portion 87a disposed between the flanges 71 and 72 of the outer valve 54, and a camshaft 17 2 A cam mounted on the cam rocker shaft 81 so as to be swingable for driving by the cam 92. Side second rocker arm 93, a rod-like second push rod 94 having one end swingably connected to the cam side second rocker arm 93, and the other end of the second push rod 94 are swingably connected to the valve side rocker. The valve 86 includes a valve-side second rocker arm 97 that is swingably attached to the shaft 86 and has a distal end portion 97 a disposed between the flanges 73 and 74 of the inner valve 55, and a compression coil spring 98 disposed between the flanges 72 and 73.

The first cam 82 and the second cam 92 are formed in shapes that satisfy valve timing characteristics described later of the outer valve 54 and the inner valve 55.
The cam-side first rocker arm 83 is a curved part, has a follower 101 that slides with the first cam 82 at one end, a protruding portion 83a into which an adjusting bolt 102 is screwed at the other end, and a through hole 83b at an intermediate portion. And a concave spherical surface 83c constituting a part of the spherical surface is formed in the through hole 83b. Reference numerals 103 and 104 denote lock nuts for the adjusting bolt 102.

  The first push rod 84 has a convex spherical surface 84a constituting a part of a spherical surface at one end and a convex spherical surface 84b constituting a part of the spherical surface at the other end, and the convex spherical surface 84a and the cam side first rocker arm. A concave spherical surface 83c of 83 is slidably fitted. The concave spherical surface 83 c and the convex spherical surface 84 a are parts constituting the spherical plain bearing 106.

The valve side first rocker arm 87 is a component in which a through hole 87b is formed in an intermediate portion, and a concave spherical surface 87c constituting a part of a spherical surface is formed in the through hole 87b.
The concave spherical surface 87c of the valve side first rocker arm 87 and the convex spherical surface 84b of the first push rod 84 are slidably fitted. The concave spherical surface 87 c and the convex spherical surface 84 b are parts constituting the spherical plain bearing 107.

  The cam-side second rocker arm 93 is opposed to the first arm 93a having a follower 111 attached to the tip, the second arm 93c having a concave spherical surface 93b formed at the tip, and the protruding portion 83a of the cam-side first rocker arm 83. And a projecting portion 93d extending in the direction.

  The second push rod 94 is a part provided with thin shaft portions 94a and 94b at each end, and formed with spherical portions 94c and 94d at the tips of the thin shaft portions 94a and 94b, respectively. The concave spherical surface 93b of the second rocker arm 93 is slidably fitted. The concave spherical surface 93b and the spherical body portion 94c are portions constituting the spherical plain bearing 113.

  The valve side second rocker arm 97 is formed with a bulging portion 97b at the intermediate portion, and a concave spherical surface 97c constituting a part of the spherical surface is formed on the bulging portion 97b, and the concave spherical surface 97c and the second push rod 94 are connected to each other. The spherical portion 94d is slidably fitted. The concave spherical surface 97c and the spherical body portion 94d are portions constituting the spherical plain bearing 114.

  The adjusting bolt 102 adjusts the distance between the tip end portion 102a and the protruding portion 93d of the cam-side second rocker arm 93, and the angle until the protruding portion 93d and the tip end portion 102a of the adjusting bolt 102 abut can be changed. It was.

  The second cam 92 causes the cam-side second rocker arm 93 to swing clockwise, the inner valve 55 starts to open via the second push rod 94 and the valve-side second rocker arm 97, and then the protruding portion 93d of the adjusting bolt 102 The cam side first rocker arm 83 starts to swing together with the cam side second rocker arm 93 by hitting the tip 102a, and the outer valve 54 begins to open via the first push rod 84 and the valve side first rocker arm 87. Therefore, the adjustment bolt 102 is a component that adjusts the valve opening timing of the outer valve 54.

  Further, the first cam 82 causes the cam-side first rocker arm 83 to swing counterclockwise, the outer valve 54 begins to close via the first push rod 84 and the valve-side first rocker arm 87, and then the tip of the adjusting bolt 102 When the portion 102a hits the protruding portion 93d, the cam-side second rocker arm 93 begins to swing together with the cam-side first rocker arm 83, and the inner valve 55 begins to close via the second push rod 94 and the valve-side second rocker arm 97. Therefore, the adjustment bolt 102 is also a component that adjusts the closing timing of the inner valve 55.

4A and 4B are explanatory diagrams (first embodiment) showing valve timing characteristics of the intake and exhaust valves according to the present invention.
(A) is a graph showing valve timing characteristics, wherein the vertical axis represents the lift amount of each outer valve and each inner valve of the intake / exhaust valve, and the horizontal axis represents the crank angle (unit: °). The lift amount is based on the valve seat for the outer valve, and is based on the outer valve for the inner valve.
For example, the inner valve of the exhaust valve opens at −180 ° and closes at the crank angle c1.
The outer valve of the exhaust valve opens at the crank angle −c2 and closes at the top dead center.
The inner valve of the intake valve opens at a crank angle −c3 and closes at 180 °.
The outer valve of the intake valve opens at the top dead center and closes at the crank angle c4.

  In this way, the outer and inner valves of the exhaust valve open and close almost simultaneously, the outer and inner valves of the exhaust valve open and close almost simultaneously, and the outer valves of the intake and exhaust valves do not overlap near top dead center. The inner and outer valves of the intake / exhaust valves open overlappingly only near top dead center.

(B) is based on the graph of (a), and the lift amount of each inner valve of the intake / exhaust valve is rewritten to the lift amount from the valve seat as in the outer valve.
That is, each inner valve of the intake / exhaust valve has a higher lift amount than each outer valve of the intake / exhaust valve.

FIGS. 5A and 5B are cross-sectional views (first embodiment) showing an open / closed state with valve timing characteristics of the intake and exhaust valves according to the present invention.
(A) is a figure which shows the open / close state of the intake valve 43 at the crank angle c5 in the graphs of FIGS. 4 (a) and 4 (b), in which the outer valve 54 is lifted from the valve seat 45 and the inner valve 55 is the outer valve. 54 shows a state in which both the outer passage 120 (the passage between the valve seat 45 and the outer valve 54) and the inner passage 60 are opened after being lifted from 54.

Thereby, the effective opening area of the intake valve 43 can be increased, the amount of intake air can be increased, and the engine output can be increased.
Further, the exhaust valve 46 (see FIG. 1) can also reduce the exhaust resistance by opening the outer valve 65 (see FIG. 1) and the inner valve 66 (see FIG. 1) simultaneously.

FIG. 4B is a view showing the open / close state of the intake valve 43 and the exhaust valve 46 at the TDC in the graphs of FIGS. 4A and 4B, and the outer valve 54 of the intake valve 43 is seated on the valve seat 45, The inner valve 55 is lifted from the outer valve 54 to open the inner passage 60. Similarly, the outer valve 65 of the exhaust valve 46 is seated on the valve seat 47, and the inner valve 66 is lifted from the outer valve 65 to the inner passage. The state which opened 60 is shown.
34 c in the figure is an annular taper portion provided on the periphery of the top surface 34 b of the piston 34 in order to generate squish by being brought close to the concave taper wall 38 f provided on the periphery of the combustion chamber wall 38 a.

  As a result, the air-fuel mixture flows from the intake port 38d through the inner passage 60 into the combustion chamber 40 as indicated by the solid arrow, and remains in the combustion chamber 40 after combustion as indicated by the broken arrow. The remaining residual gas flows out through the inner passage 60 to the exhaust port 38e.

  Thus, by opening only the inner valves 55, 66 near the top dead center at the end of the exhaust stroke, the lift amount of the inner valves 55, 66 can be increased without causing interference with the top surface 34b of the piston 34. The amount of air-fuel mixture to be sucked in and the amount of residual gas to be exhausted can be increased, and scavenging can be performed more reliably. Furthermore, since it is not necessary to provide a valve recess on the top surface 34b of the piston 34, the area of the taper portion 34c serving as the squish area of the piston 34 can be increased, and squish can be generated more effectively.

  As shown in FIGS. 1 to 5, the present invention is an internal combustion engine in which the cylinder head 22 is provided with the intake valve 43 and the exhaust valve 46 that open and close the intake port 38 d and the exhaust port 38 e communicating with the combustion chamber 40, respectively. 10, the intake valve 43 is a double valve comprising an outer valve 54 having an inner valve hole 54a penetrating in the axial direction and an inner valve 55 movably inserted into the inner valve hole 54a. A double valve comprising an outer valve 65 having an inner valve hole 54a penetrating in the axial direction and an inner valve 66 movably inserted into the inner valve hole 54a. The intake and exhaust ports 38d are connected to the outer valves 54 and 65, respectively. 38e and the combustion chamber 40 are communicated with each other, and an inner passage 60 that is opened and closed by inner valves 55 and 66 is formed. 4 and 65 and a first cam 82 and a second cam 92 as valve timing control devices for controlling the opening and closing of the inner valves 55 and 66, and the first cam 82 and the second cam 92 absorb at least during scavenging. The outer valves 54 and 65 of the exhaust valves 43 and 46 are closed at the same time, and the inner valves 55 and 66 of the intake and exhaust valves 43 and 46 are opened at the same time.

  As a result, scavenging near the top dead center in the high rotation region can be performed more reliably, and the valve recess of the top surface 34b of the piston 34 can be eliminated, and the tapered portion 34c as the squish area can be increased. The output performance and combustion efficiency can be improved.

The operation of the intake side valve mechanism 48 described above will be described with reference to FIGS. The first cam 82, the second cam 92, the intake valve 43, and the intake valve mechanism 48 are shown in a simplified manner.
6A and 6B are first operation diagrams (first embodiment) showing the operation of the intake side valve mechanism according to the present invention.
(A) The intake side valve mechanism 48 is connected to the cam shaft 17, the cam side first rocker arm 83 driven by the first cam 82 of the cam shaft 17, and one end connected to the cam side first rocker arm 83. The first push rod 84, the valve side first rocker arm 87 connected to the other end of the first push rod 84, the cam side second rocker arm 93 driven by the second cam 92 of the camshaft 17, and the cam. A second push rod 94 having one end connected to the second side rocker arm 93, a valve side second rocker arm 97 connected to the other end of the second push rod 94, and the outer valve 54 and the inner valve 55. It shows that both the outer valve 54 and the inner valve 55 of the intake valve 43 are closed.

  In (b), when there is an input from the second cam 92 to the cam-side second rocker arm 93 as shown by an arrow A, the cam-side second rocker arm 93 moves the second rocker shaft 81 as shown by an arrow B. Swing around the center.

  As a result, the second push rod 94 moves as indicated by the arrow C, the valve side second rocker arm 97 swings around the valve side rocker shaft 86 as indicated by the arrow D, and the inner valve 55 Move as shown by arrow E to open the inner passage 60.

FIGS. 7A and 7B are second operation diagrams (first embodiment) showing the operation of the intake side valve mechanism according to the present invention.
In (a), when the cam side second rocker arm 93 further swings as indicated by an arrow F by further input from the second cam 92, the protruding portion 93d of the cam side second rocker arm 93 is adjusted bolt (not shown). The cam-side first rocker arm 83 swings as indicated by an arrow G in order to push the protruding portion 83a of the cam-side first rocker arm 83 through.

As a result, the first push rod 84 moves as indicated by the arrow H, the valve side first rocker arm 87 swings about the valve side rocker shaft 86 as indicated by the arrow J, and the outer valve 54 Move as shown by arrow K to open the outer passage 120. While the outer valve 54 is open, the inner valve 55 is further opened.
At this time, the lift amounts based on the valve seats of the outer valve 54 and the inner valve 55 are L1 and L2, respectively.

  In (b), when there is an input from the first cam 82 to the cam-side first rocker arm 83 as indicated by an arrow M, the cam-side first rocker arm 83 moves the first rocker shaft 81 as indicated by an arrow N. Swing around the center.

  As a result, the first push rod 84 moves as indicated by the arrow P, the valve side first rocker arm 87 swings around the valve side rocker shaft 86 as indicated by the arrow Q, and the outer valve 54 As shown by the arrow R, the inner and outer passages 120 are closed.

  While the cam-side first rocker arm 83 is swinging, the protrusion 83a pushes the protrusion 93d to swing the cam-side second rocker arm 93 as indicated by an arrow S. As a result, the second push rod 94 moves as indicated by the arrow T, the valve side second rocker arm 97 swings about the valve side rocker shaft 86 as indicated by the arrow U, and the inner valve 55 Move as shown by arrow V.

FIG. 8 is a third action diagram (first embodiment) showing the action of the intake side valve mechanism according to the present invention.
When the second cam 92 is gradually retracted relative to the cam-side second rocker arm 93 as indicated by the arrow W, the cam side is acted upon by the elastic force of the compression coil spring 98 (acting in the direction of the white arrow X). The second rocker arm 93 swings as indicated by arrow Y, the second push rod 94 moves as indicated by arrow Z, the valve side second rocker arm 97 swings as indicated by arrow AA, and the inner valve 55 It moves as shown by BB and closes the inner passage 60.

  As shown in FIGS. 6 to 8, the rotation of the camshaft 17 first opens the inner valve 55 by the second cam 92 and then opens the outer valve 54. Then, the outer valve 54 is closed by the first cam 82, and then the inner valve 55 is closed by the first cam 82 and the compression coil spring 98.

As shown in FIGS. 1, 2, 3, and 5, the present invention provides the cylinder head 22 with the intake valve 43 and the exhaust valve that open and close the intake port 38 d and the exhaust port 38 e that communicate with the combustion chamber 40, respectively. In the internal combustion engine 10 provided with 46, a double valve comprising an outer valve 54 having an inner valve hole 54a penetrating the intake valve 43 in the axial direction and an inner valve 55 movably inserted into the inner valve hole 54a. The exhaust valve 46 is a double valve composed of an outer valve 65 having an inner valve hole 54a penetrating in the axial direction and an inner valve 66 movably inserted into the inner valve hole 54a. In addition, the intake and exhaust ports 38d and 38e and the combustion chamber 40 are communicated with each other, and an inner passage 60 that is opened and closed by inner valves 55 and 66 is formed. The first cam 82 and the second cam 92 are provided as valve timing control devices for controlling the opening and closing of the outer valves 54 and 65 and the inner valves 55 and 66. The first cam 82 and the second cam 92 exhaust the exhaust gas in the exhaust stroke. The outer valve 65 and the inner valve 66 of the valve 46 are opened, and the outer valve 54 and the inner valve 55 of the intake valve 43 are opened in the intake stroke.
As a result, the effective opening area of the intake / exhaust valve can be increased, the intake air amount can be increased, and the engine output can be improved.

FIG. 9 is a cross-sectional view (second embodiment) showing an intake valve and an intake side valve mechanism according to the present invention. The same components as those in the first embodiment shown in FIG. Omitted.
The intake side valve mechanism 130 is a mechanism for forcibly opening and closing the outer valve 54 and the inner valve 55, and includes a cam side rocker shaft 81, a first cam 131, a second cam 132, a third cam 133, and a fourth cam. Of the camshaft 135 formed of 134, a first valve opening arm 137 applied to the first cam 131 and a first valve closing arm 138 applied to the second cam 132 are provided, and the cam side rocker shaft 81 is swingable. The attached cam side first rocker arm 143, a cylindrical first push rod 84 having one end swingably connected to the cam side first rocker arm 143, a valve side rocker shaft 86, a valve side first rocker arm 87, A second valve opening arm 141 applied to the third cam 133 and a second valve closing arm 142 applied to the fourth cam 134 are provided. A cam-side second rocker arm 153 swingably attached to the side rocker shaft 81, a rod-like second push rod 94 having one end swingably connected to the cam-side second rocker arm 153, and a valve-side second rocker arm 97. Become.

  The cam-side first rocker arm 143 is a part that is curved in a substantially C-shape, and includes a follower 145 that slides with the first cam 131 at the tip of the first valve-opening arm 137, and the first valve-closing arm 138. A follower 146 that slides with the second cam 132 is provided at the tip, and a through hole 83b is formed in an intermediate portion of the first valve closing arm 138, and a concave spherical surface 83c constituting a part of the spherical surface is formed in the through hole 83b. Is.

  The first cam 131 to the fourth cam 134 are formed into shapes that satisfy the valve timing characteristics shown in FIG. 10 of the outer valve 54 and the inner valve 55.

  The cam-side second rocker arm 153 is a substantially C-shaped curved part, and includes a follower 147 that slides with the third cam 133 at the tip of the second valve-opening arm 141. A follower 148 that slides with the fourth cam 134 is provided at the tip, and a concave spherical surface 93 b is formed at the intermediate portion of the second valve closing arm 142.

FIG. 10 is a graph showing valve timing characteristics (second embodiment) of the intake / exhaust valve according to the present invention. The vertical axis represents the lift amount of each outer valve and each inner valve of the intake / exhaust valve, and the horizontal axis represents the crank angle ( The unit is °). The lift amount is based on the valve seat for the outer valve, and is based on the outer valve for the inner valve.
For example, the outer valve of the exhaust valve opens at -180 ° and closes at top dead center.
The inner valve of the exhaust valve opens at a crank angle −c6 and closes at a crank angle c7.
The outer valve of the intake valve opens at top dead center and closes at 180 °.
The inner valve of the intake valve opens at a crank angle −c8 and closes at a crank angle c9.
As described above, the outer valves of the intake / exhaust valves do not overlap near the top dead center, and the inner valves of the intake / exhaust valves open overlappingly only near the top dead center.
The open / close state of the intake valve 43 and the exhaust valve 46 at the top dead center in this valve timing characteristic is the same as that shown in FIG.

11 (a) and 11 (b) are explanatory diagrams showing valve timing characteristics (third embodiment) of the intake valve according to the present invention.
(A) is a graph showing valve timing characteristics, where the vertical axis represents the lift amount of each outer valve of the intake valve, and the horizontal axis represents the crank angle (unit: °). The lift amount is based on the valve seat.
For example, of the pair of outer valves, one outer valve (this is referred to as a first outer valve) opens at top dead center and closes at 180 °.
Of the pair of outer valves, the other outer valve (this is referred to as a second outer valve) opens at the crank angle c10 and closes at the crank angle c11.
Thus, the first outer valve opens early and closes late with respect to the second outer valve.

(B) is a figure which shows opening and closing at the crank angle c12 of a pair of intake valve provided with the outer side valve in (a).
That is, the pair of intake valves is a first intake valve 43A and a second intake valve 43B (the first intake valve 43A and the second intake valve 43B have the same structure as the intake valve 43), and the first intake valve 43A is the same. The first outer valve 54A and the first inner valve 55A are configured, and the second intake valve 43B is configured by the second outer valve 54B and the second inner valve 55B. Note that θ is a valve clamping angle between the first intake valve 43A and the second intake valve 43B.

  The first outer valve 54A of the first intake valve 43A opens earlier than the second outer valve 54B of the second intake valve 43B, and the lift amount is large. In this way, by making the valve timings of the first outer valve 54A and the outer valve 54B different, the first outer valve 54A and the second outer valve 54A are large even if the outer shapes of the first outer valve 54A and the second outer valve 54B are large. The effective opening areas of the first outer valve 54A and the outer valve 54B can be increased by overlapping so as not to interfere with 54B. Furthermore, by opening the first inner valve 55A and the second inner valve 55B, the effective opening area can be further increased.

  Further, even if the lift amount is increased, the intake valves 43A and 43B do not interfere with each other, so that the valve sandwiching angle θ can be increased, whereby the intake valves 43A and 43B, more specifically, the outer valves 54A and 54B, the inner valves It becomes possible to enlarge the outer shape of each of the umbrella portions 55A and 55B, and further increase the effective opening area.

  As shown in FIGS. 1, 2, and 9, the present invention provides a plurality of intake air in the internal combustion engine 10 in which the plurality of intake valves 43 </ b> A, 43 </ b> B and the exhaust valves 46 are arranged radially with respect to the cylinder axis 28. Valves 43A and 43B, specifically, valve opening and closing that prevents interference between the plurality of intake valves 43A and 43B by controlling the opening and closing of the outer valves 54A and 54B and the inner valves 55A and 55B with different valve timings and different lift amounts. A first cam 82 and a second cam 92 are provided as control means.

  Thereby, interference of each intake valve 43A, 43B can be prevented, and the valve lift amount can be increased. Further, the valve sandwiching angle θ can be increased, and the outer shape of the umbrella portion can be increased. As described above, the opening areas of the intake valves 43A and 43B can be increased, the intake air amount can be increased, and the output of the internal combustion engine can be improved.

  Further, by increasing the valve clamping angle θ, when the intake valves 43A and 43B are opened, the distance between the intake valves 43A and 43B and the combustion chamber wall can be increased, and the effective openings of the intake valves 43A and 43B can be increased. As the area increases, the intake air amount can be further increased.

Further, at least one of the intake valve 43 and the exhaust valve 46 is characterized in that the umbrella portions 58, 63, 71, 75 are non-circular.
Thereby, an opening area can be enlarged more and the further increase in intake air amount can be aimed at.

As shown in FIGS. 3 and 6 to 8, the present invention converts the rotation of the camshaft 17 into an opening / closing operation of the intake valve 43 via the push rods 84 and 94 and the rocker arms 87 and 97. In the intake side valve operating mechanism 48 of the internal combustion engine 10 (see FIG. 1), the intake valve 43 has an outer valve 54 having an inner valve hole 54a penetrating in the axial direction, and an inner side movably inserted into the inner valve hole 54a. The intake / exhaust ports 38d, 38e and the combustion chamber 40 are communicated with the outer valve 54, and an inner passage 60 that is opened and closed by the inner valve 55 is formed. In addition, the cam contacts the first cam 82 as the cam for the outer valve provided on the camshaft 17 to open and close the outer valve 54 and the cam side as the first rocker shaft A cam side first rocker arm 83 as a first rocker arm for an outer valve supported by a rocker shaft 81 in a swingable manner, and a first push rod 84 as an outer valve push rod having one end connected to the cam side first rocker arm 83; The first rocker arm on the valve side as the second rocker arm for the outer valve connected to the other end of the first push rod 84 and swingably supported by the valve side rocker shaft 86 as the second rocker shaft and connected to the outer valve 54. 87 and a cam serving as a first rocker arm for an inner valve that is supported by a cam-side rocker shaft 81 and is swingably supported by a second cam 92 serving as an inner valve cam provided on the camshaft 17 to open and close the inner valve 55. Side second rocker arm 93 and the cam side first A second push rod 94 as an inner valve push rod connected at one end to the rocker arm 93, and connected to the other end of the second push rod 94 and supported by the valve-side rocker shaft 86 in a swingable manner, and connected to the inner valve 55. A valve-side second rocker arm 97 as a second rocker arm for the inner valve connected, and one of the cam-side first rocker arm 83 and the cam-side second rocker arm 93 is driven by the first cam 82 or the second cam 92. Protrusions 83a and 93d are formed as drive arms that are sometimes pushed to drive the other, and one of the first push rod 84 and the second push rod 94 is formed in a cylindrical shape, and the inner side of the cylindrical push rod 84 is formed. By disposing the other of the first push rod 84 and the second push rod 94 on the two push rods, When the shrods 84 and 94 are arranged substantially coaxially and the inner valve 55 is opened and closed, the outer valve 54 side is driven via the protrusions 83a and 93d, and when the outer valve 54 is opened and closed, the protrusions 83a and 93d are interposed. And driving the inner valve 55 side.
Thereby, both the outer valve 54 and the inner valve 55 can be opened simultaneously, the intake air amount can be increased, and the output of the internal combustion engine can be improved.

Further, the present invention is characterized in that a compression coil spring 98 as a spring for forcibly closing the inner valve 55 with respect to the outer valve 54 is interposed between the outer valve 54 and the inner valve 55.
As a result, the inner valve 55 can be reliably closed by the compression coil spring 98 with respect to the outer valve 54, and sealing performance can be ensured.

  FIG. 12 is a plan view (fourth embodiment) showing a mechanism for generating an elastic force between the outer valve and the inner valve according to the present invention. In place of the compression coil spring 98 shown in FIG. This shows that a torsion coil spring 161 is interposed between the first rocker arm 83 and the cam-side second rocker arm 93.

  Specifically, the cam side first rocker arm 83 and the cam side second so that the small diameter portion 167 provided at one end of the cam side first rocker arm 83 and the small diameter portion 168 provided at one end of the cam side second rocker arm 93 are adjacent to each other. The rocker arm 93 is swingably attached to the cam side rocker shaft 81, the torsion coil spring 161 is fitted to the small diameter portions 167 and 168, and the bent portion 161a provided at one end of the torsion coil spring 161 is hung on the protruding portion 83a. A bent portion 161b provided at the other end of the spring 161 is hung on the protruding portion 93d. Thereby, the protrusion 83a and the protrusion 93d are urged away by the torsion coil spring 161.

  The intake / exhaust device of the present invention is suitable for an internal combustion engine of a two-wheeled vehicle or a four-wheeled vehicle.

1 is a cross-sectional view (first embodiment) of an internal combustion engine including an intake / exhaust device according to the present invention. It is a figure (1st Embodiment) which shows arrangement | positioning of the intake / exhaust valve | bulb which concerns on this invention. It is sectional drawing (1st Embodiment) which shows the intake valve and intake side valve operating mechanism which concern on this invention. It is explanatory drawing (1st Embodiment) which shows the valve timing characteristic of the intake / exhaust valve which concerns on this invention. It is sectional drawing (1st Embodiment) which shows the open / close state in the valve timing characteristic of the intake / exhaust valve | bulb which concerns on this invention. FIG. 3 is a first operation diagram (first embodiment) showing an operation of the intake side valve mechanism according to the present invention. FIG. 6 is a second action diagram (first embodiment) showing the action of the intake side valve mechanism according to the present invention. FIG. 6 is a third action diagram (first embodiment) showing the action of the intake side valve mechanism according to the present invention. It is sectional drawing (2nd Embodiment) which shows the intake valve and intake side valve operating mechanism which concern on this invention. It is a graph which shows the valve timing characteristic (2nd Embodiment) of the intake / exhaust valve which concerns on this invention. It is explanatory drawing which shows the valve timing characteristic (3rd Embodiment) of the intake valve which concerns on this invention. It is a top view (4th Embodiment) which shows the mechanism which generates an elastic force between the outer side valve | bulb and inner side valve | bulb which concern on this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Internal combustion engine, 22 ... Cylinder head, 38d ... Intake port, 38e ... Exhaust port, 40 ... Combustion chamber, 43 ... Intake valve, 46 ... Exhaust valve, 54, 65 ... Outer valve, 54a ... Inner valve hole, 55, 66 ... Inner valve, 60 ... Inner passage, 82, 92 ... Valve timing control device (first cam, second cam).

Claims (2)

In the internal combustion engine provided with an intake / exhaust valve for opening / closing an intake / exhaust port leading to the combustion chamber in the cylinder head,
The intake / exhaust valve is a double valve composed of an outer valve having an inner valve hole penetrating in the axial direction and an inner valve movably inserted into the inner valve hole,
The outer valve is connected to the intake / exhaust port and the combustion chamber and forms an inner passage that is opened and closed by the inner valve,
The valve timing control device for controlling the opening and closing of the outer valve and the inner valve, the valve timing control device is in a non-overlapping state in which the outer valves of the intake and exhaust valves are simultaneously closed at least during scavenging. An intake / exhaust device for an internal combustion engine, wherein the inner valves of the intake / exhaust valves are opened in an overlapping state simultaneously. In the internal combustion engine provided with an intake / exhaust valve for opening / closing an intake / exhaust port leading to the combustion chamber in the cylinder head,
The intake / exhaust valve is a double valve composed of an outer valve having an inner valve hole penetrating in the axial direction and an inner valve movably inserted into the inner valve hole,
Forming the inner passage opened and closed by the inner valve while communicating the intake and exhaust ports and the combustion chamber to the outer valve;
A valve timing control device that controls opening and closing of the outer valve and the inner valve is provided. The valve timing control device opens the outer valve and the inner valve of the exhaust valve in the exhaust stroke, and the outside of the intake valve in the intake stroke. An intake / exhaust device for an internal combustion engine, wherein each of the valve and the inner valve is opened.

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