ES2317735A1 - Internal combustion engine - Google Patents

Abstract

Internal combustion engine. Problem: An element is provided to regulate the axial movement of the oscillating arm in a cylinder head cover, thus effectively limiting the axial movement of the oscillating arm and preventing the increase in the elastic load of a pressure spring, thereby facilitating the axial movement of the oscillating arm against the elastic load of the spring at the time of adjusting the clearance of the pusher or the like to achieve an improvement in the workability of the adjustment operation. Solution: Swing arms 71, 72 swingably supported on two respective swing arm shafts 7, 7 are pressed in one direction by springs 81, 82 to regulate their axial movement. Furthermore, the axial movement of the swing arms 71, 72, projections 71e, 72e arranged on the swing arms 71, 72 abut against movement regulating elements provided on the inner surface of the upper wall portion of a cylinder head cover. Therefore, the axial movement of the oscillating arms 71, 72 can be limited without increasing the elastic loads of the springs 81, 82, and the movement of the oscillating arms 71, 72 against the elastic loads of the springs 81 is facilitated, 82 at the time of adjusting the clearance of the pusher or the like. (Machine-translation by Google Translate, not legally binding)

Description

Internal combustion engine.

Technical field

The present invention relates to a Enhanced structure of an internal combustion engine, and more specifically to an improved structure of a combustion engine internal that includes an improvement of the structure to regulate the swing arm position.

Prior art

A conventional swing arm supported oscillatingly on an oscillating arm axis is pressed and axially pushed by a spring to regulate its axial movement. The pressure and thrust of the swing arm by the spring is carried out using a spring for which a relatively load is established large to effectively regulate axial arm movement oscillating due to vibration during the operation of an engine.

On the other hand, with the swing arm that has the aforementioned structure, when replacing a wedge provided in a top seat of a valve during space adjustment free of the pusher, the swing arm must be moved axially. To move the swing arm axially, the spring must compress and press against the large spring load that press and push the swing arm (see, for example, the Patent Document 1).

Patent Document 1: JP-A No. 316633/2004 (pages 2 to 3, figure 3).

Description of the invention Problem to solve with the invention

As described above, the Document of Patent 1 mentioned above describes a structure in the that the oscillating arm swungly supported on the arm axis oscillating is pressed and pushed axially by the spring to regulate its axial movement. According to this arm structure swing, pressure and thrust of the swing arm by the spring it is done using a push spring that has a load relatively large spring to regulate the axial movement of the swing arm due to vibration during engine operation previously described.

However, the pressure and the thrust of the arm swinging by the large spring load to regulate the movement axial swing arm makes it difficult to move the swing arm against spring loading when replacing the wedge provided in the upper valve seat while adjusting clearance of the pusher or the like, thus deteriorating the workability of the wedge replacement.

In view of the circumstances described previously, the present invention provides an engine of internal combustion that has a swing arm structure according to which a cylinder head cover is provided with an element which contacts the swing arm to regulate axial movement of the swing arm, therefore effectively regulating the axial movement of the swing arm due to vibration or the like during engine operation, while eliminating need to push down the pier that has a large load of spring as described above, and facilitating it time the axial movement of the oscillating arm during operation of adjustment of the free space of the pusher or the like to achieve Better workability of the regulation operation.

The present invention relates to a improved structure of an internal combustion engine that has a  swing arm structure to solve problems before indicated. According to one aspect of the invention in claim 1, an internal combustion engine is provided including: a chamber valve formed by a cylinder head and a cover of butt; and an oscillating arm oscillatingly supported and axially movable on a swing arm axis arranged in the valve chamber, the swing arm being pushed axially by an elastic element, where the cylinder head cover includes a regulatory element to regulate the axial movement of the arm oscillating in a state where the cylinder head cover is mounted on the cylinder head.

According to one aspect of the invention in the claim 2, the swing arm has a protruding projection radially, and the regulating element contacts the projection.

In addition, according to an aspect of the invention in the claim 3, the regulatory element is integrally formed with the head cover, and has at its distal end portion a concave portion lowered along the oscillating arm axis.

Effect of the invention

According to the aspect of the invention in the claim 1, in an internal combustion engine including: a valve chamber formed by a cylinder head and a cover of cylinder head; and an oscillating arm oscillatingly supported and axially movable on a swing arm axis arranged in the valve chamber, the swing arm being pushed axially by an elastic element, the head cover includes an element regulator to regulate the axial movement of the oscillating arm in a state where the cylinder head cover is attached on the cylinder head of cylinder. Therefore, since the load should not be increased of the elastic element, the axial movement of the swing arm is can easily be done by regulating the movement at the same time axial swing arm, thus facilitating the operation of regulation of the free space of the pusher.

According to the aspect of the invention in the claim 2, in the aspect of the invention in claim 1, the swing arm has a projection that projects radially, and the regulatory element contacts the projection, so that the contact between the swing arm and the regulator element can be carried out easily without being hindered by other elements such as a dock.

According to the aspect of the invention in the claim 3, in the aspect of the invention in claim 1 or 2, the regulating element is formed integrally with the cover cylinder head, and has a portion on its distal end concave lowered along the swing arm axis, so the regulatory element can be produced cheaply due to the integral formation. In addition, due to the concave portion, the regulator element can be placed near the swing arm axis as much as possible while ensuring a free space between the regulator element and swing arm axis, so the Swing arm movement can be regulated reliably.

Brief description of the drawings

Figure 1 is a longitudinal sectional view. which represents the main structural portion of the portion top of an internal combustion engine according to the present invention.

Figure 2 is a top view that represents a partial section of a cylinder head in a state in which a cylinder head cover according to the present invention It is separated.

Figure 3 is a side sectional view of a cylinder head portion according to the present invention.

Figure 4 is a view representing the cylinder head cover according to the present invention, illustrating the inner surface place of the cylinder head cover.

Figure 5 is a sectional view taken at along the V-V line in figure 4.

Figure 6 is a sectional view taken at along line VI-VI in figure 4.

Description of reference numbers

3:

cylinder head

4:

cylinder head cover

4c, 4d:

motion regulator element

51, 52:

intake / exhaust valve

51c, 52c:

upper end of valve stem

6:

camshaft

61, 62:

eccentric valve

7:

swing arm shaft

71, 72:

swing arm

71a, 72a:

main arm body portion rocking

72c:

a portion of arm

72d:

another arm portion

72e:

outgoing

72f:

roller

81, 82:

dock

Best way to put the invention into practice

An embodiment of the present invention is describe with reference to figures 1 to 6.

Figure 1 illustrates the structure of a portion  top of an internal combustion engine E according to the present invention mounted on a motorcycle. Combustion engine internal E is a four-cylinder internal combustion engine times, cylinder head valve. The main body portion of the internal combustion engine E consists of a splitter housing laterally 1 consisting of a left crankcase and a crankcase right and of which only one part is represented, a block of cylinders 2 fixed to an upper portion of the crankcase 1, a cylinder head of cylinder 3 fixed to an upper portion of the cylinder block 2, and a cylinder head cover 4 fixed to the cylinder head 3 for cover the upper portion of the cylinder head 3. A crankshaft 1a, of which only one part is represented, is supported rotatably by a bearing inside the crankcase 1.

A crank 1d is mounted on the crankshaft 1a having a large end portion 1c as its supported end rotatably in a wrist portion 1b of the crankshaft 1a. A P piston is swiveled by a piston pin 1f at a small end portion what is the other end of the 1d connecting rod Upon receiving combustion energy in a chamber of combustion 3a which will be described later, the piston P is pushed down into a cylinder hole 2a arranged in the cylinder block 2, it causes the crankshaft 1a to rotate by the crank 1d, and performs alternative movement inside the hole of cylinder 2a when the crankshaft 1a rotates.

As described above, in the block of cylinders 2, the cylinder hole 2a and the chamber of combustion 3a located above the cylinder hole 2a. In addition, the cylinder block 2 is provided with a hole that extends vertically 2b for a timing chain Tc to activate a camshaft 6, a water jacket 2 for water circulation of refrigeration, and the like.

Cylinder head 3 has, at the junction between cylinder head 3 and cylinder block 2 below the cylinder head 3, the combustion chamber 3a formed in cooperation with the cylinder hole 2a described above. A spark plug 3b is provided in the combustion chamber 3a looking at the combustion chamber 3a. In addition, as represented in figure 3, the combustion chamber 3a is provided with intake and exhaust holes 3e, 3f that communicate with steps of intake and exhaust 3c, 3d, and intake and exhaust valves 51, 52 to open and close the intake and exhaust holes 3e, 3f, respectively. Although not clearly shown, the holes of intake and exhaust 3e, 3f consist of four holes; two holes somewhat large serve as the 3e intake holes, and two somewhat small holes serve as 3f escape holes.

Holes 3e, 3f are closed by heads of valve 51a, 52a by raising the intake valves and exhaust 51, 52 via valve stems 51b, 52b due to the elastic forces of valve springs 51d, 52d, except of during the depression action performed when the portions of contact 71d1, 71d2 of arm portions 71d, 72d of arms oscillating 71, 72 push the upper rod ends of valve 51c, 52c according to the pivoting movement of the eccentrics of valve 61, 62 in a valve mechanism A which will be described later.

In addition, the valve mechanism A described above  to operate the intake and exhaust valves 51, 52 to opening and closing is provided above the cylinder block 2. Although its construction has been partially described above, the Valve mechanism A is generally composed of camshaft 6, the two valve eccentrics 61, 62 arranged in the shaft of cams 6, the swinging arms 71, 72 that in one of its portions of arm 71c, 72c have rollers 71f, 72f that contact the eccentric valve 61, 62, and intake and exhaust valves 51, 52 having the upper ends of the valve stem 51c, 52c that contact the contact portions 71d1, 72d1 of the other arm portions 71d, 72d of the swinging arms 71, 72 and They are pushed by the contact portions.

With reference to figure 1, the camshaft 6 is rotatably supported on cylinder head 3 having its end, a left side end 6a as seen in the drawing, supported in a 3g1 hole portion of a 3g wall portion, which is the left side wall portion as seen in the drawing, of cylinder head 3, and having its other end, is that is, a shaft portion 6c near a right side end 6b as seen in the drawing, supported by a ball bearing B in the other wall portion 3h, which is the side wall portion right as seen in the drawing, of cylinder head 3. A pinion 6e is attached to an axial shaft end portion 6d that protrudes from the other wall portion 3h as the wall portion right side as seen in the cylinder head 3 drawing. The camshaft 6 is rotated at half the rpm of the crankshaft 1a through the timing chain Tc suspended between the pinion 6e and a pinion (not shown) mounted on the crankshaft 1st.

As can be seen with reference to the Figures 1 to 3, above the camshaft 6 of the cylinder head 3 two axes 7, 7 parallel to the camshaft 6 and in positions where, as seen in the plan view (view from above) in figure 2, axes 7, 7 are facing each other with camshaft 6 (not shown in figure 2) In between.

The two axes 7, 7 are swing arm axes 7 for mounting and supporting the swinging arms 71, 72, and their opposite ends fit and support in 3g1, 3h1 holes of a and other wall portions 3g, 3h, which are the wall portions lower upper end as seen in figure 2, of the cylinder head 3, respectively. The 3g1 hole of a portion 3g wall is a blind hole. Although the hole 3h1 of the other 3h wall portion is formed as a through hole, its end opening 3h11 on the bottom side in figure 2 is closed, that is, it serves as a hole that closes after mounting the swing arm shaft 7 to avoid dislodging the shaft from swing arm 7.

The structure of the two 3g1 wall holes, 3h1 to support the swing arm shaft 7 is such that the assembly of the oscillating arm axis 7 in the cylinder head 3 is carried out when the distal end of the swing arm axis 7 introduced the side of the hole 3h1 is inserted and fits into the hole of wall 3g1 as the blind hole of a portion of wall 3g and it place in an appropriate position, and then the opening end 3h11 on the bottom side in the drawing, which is the side of introduction of the shaft, the 3h1 through hole is closed with a closing element.

The swinging arms 71, 72 are supported by swinging shape in the central portions substantially axes of the two oscillating arm axes 7, 7, respectively. As will be described later, the swinging arms 71, 72 will be bear respectively on the oscillating arm axes 7, 7 of so that they are oriented in opposite directions to each other. By consequently, the swinging arms 71, 72 are pushed aside axial, that is, downwards as seen in figure 2, in the case of the swing arm of the intake side 71, by a spring 81 interposed between its end 71a1 and a 3g wall portion of the cylinder head 3.

In addition, the swing arm of exhaust side 72 it is pushed to the axial side, that is, upwards as seen in Figure 2, by a spring 82 interposed between its end 72a1 and the other wall portion 3h of the cylinder head 3. By consequently, the other ends 71a2, 72a2 of the portions of swing arm main body 71a, 72a are in contact sliding with the other wall portion of the cylinder head 3. That is, the other end 71a2 of the main body portion of the swing arm of intake side 71 and the other end 72a2 of the main body portion of the swinging arm on the side of Exhaust 72 are in sliding contact with a 3h2 side end of the other wall portion 3h and a side end 3g2 of a 3g wall portion, respectively.

As depicted in Figure 3, the two swinging arms 71, 72 have substantially the same slightly arched curved configuration seen in your view side. Holes 71b, 72b that allow swinging arms 71, 72 are pivotally supported on the swing arm axis 7, are formed in the main body portions 71a, 72a which are the substantially central thick wall portions of the swinging arms 71, 72. The arm portions 71c, 72c, which are thick-walled, they extend respectively from one side of the main body portions 71a, 72a.

Thick wall arm portions 71c, 72c extending from the main body portions 71a, 72a, they extend from slightly shifted positions to the side with with respect to the respective vertical directions (the direction Axial of the oscillating arm axis 7) of the body portions main 71a, 72a as seen in the plan view of figure 2. That is, as seen in the plan view of Figure 2, the arm portions 72c extend from a displaced position to the lower side of the main body portion 71a in the arm oscillating 71, and a position shifted to the upper side of the main body portion 72a in the swing arm 72, respectively. In addition, as seen in plan view, the widths of arm portions 71c, 72c decrease near their distal ends The rollers 71f, 72f that contact respectively the valve eccentrics 61, 62 which will be described later, they are pivotally supported rotary in portions of distal end 71c1, 72c1 thus having small widths

In addition, as seen in plan view, the thin-walled arm portions 71d, 72d extending to the other side of the respective main body portions 71a, 72a of the two oscillating arms 71, 72, are formed as a pair of other arm portions 71d, 72d that diverge from each other proximal portions of main body portions 71a, 72a and gradually distance each other towards the end portion distal As seen in the plan view of Figure 2, the pair of the other arm portions 71d, 72d also extend from slightly shifted positions to the side with respect to vertical directions of main body portions 71d, 72d The distal ends of the arm portions 71d, 72d are respectively form as the contact portions 71d1, 72d1 with respect to the upper ends of valve stem 51c, 52c However, the configurations of the other portions of arm 71d, 72d, forming a pair, in the two swinging arms 71, 72 differ from each other.

The other arm portions 72d, 72d, which form a pair, of the swing arm of exhaust side 72 on the side left as seen in figure 2, they extend in directions opposite each other at substantially equal angles from the proximal portion of main body portion 72a, more exactly, at substantially equal angles with respect to the axis of the oscillating arm axis 7 so that the distance between Increase towards the distal end portion. In addition, the others arm portions 71d, 71d, forming a pair, of the swing arm of intake side 71 on the right side in the drawing, it extend from the proximal portion of the main body portion 71a in the same direction at different angles with respect to the axis of the oscillating arm axis 7 so that the distance between Increase towards the distal end portion.

As can be seen in the plan view depicted in figure 2, in the main body portions 71a, 72a of the two swinging arms 71, 72, in their portions Overhangs 71e, 72e are provided in the form of extensions of protruding portions in the form of nerves, respectively, so that they extend from the portions of main body 71a, 72a along the axial direction of the shaft with swing arm 7. The projections 71e, 72e extend from the central protruding portions of the body portions main 71a, 72a at its axial ends, and, although it cannot be appreciate in the plan view of figure 2, as you can appreciate in the side view represented in figure 1, the projections 71e, 72e extend so that they protrude radially of the main body portions 71a, 72a, that is, They extend upwards.

In addition, projections 71e, 72e extend in the spaces on the other sides in front of the positions shifted to the sides in the vertical direction as seen in the Figure 2, of which both arm portions described above 71c, 71d, 72c, 72d extend from the main body portions 71a, 72a. The projections 71e, 72e serve to limit movement axial of swinging arms 71, 72 against elastic forces of the pressure springs 81, 82 having their distal ends 71e1, 72e1, which are oriented upwards and in the axial direction of the oscillating arm axis 7, supporting against regulating elements of movement (stops) 4c, 4d (see figures 1, 3, and the like) arranged in the cylinder head cover 4 which will be described more ahead.

The swinging arms 71, 72 respectively Oscillatingly supported on the two oscillating arm axes 7, 7 are placed so that they are oriented in opposite directions one of the other. That is, the swinging arms 71, 72 are supported tiltingly on the oscillating arm axes 7, 7 at the same time which are positioned so that the rollers 71f, 72f in the distal ends 71c1, 72c1 of its arm portions 71c, 72c are located on the eccentric shaft side 6 as the side inside, and that the contact portions 71d1, 72d1 in the distal ends of the pair of the other arm portions 71d, 72d which will rest against the upper ends of the valve stem 51c, 52c, are located on the outer side.

Rotary rollers 71f, 72f at the ends distal of the arm portions 71c, 72c of the two arms oscillators 71, 72 respectively rest against the eccentrics of valve 61, 62 of the camshaft 6, described above, which are at a predetermined distance from each other. In addition, portions of contact 71d1, 71d1, 72d1, 72d1 at the distal ends of the paired arm portions 71d, 71d, 72d, 72d separated one of other, which serve as the other arm portions 71d, 72d of the swinging arms 71, 72, rest on the upper ends of valve stem 51c, 51c, 52c, 52c of the intake valves and escape 51, 52, respectively.

That is, the contact portions 71d1, 71d1 at the distal ends of the pair of separate arm portions each other 71d, 71d of the swing arm of intake side 71 support at the upper ends of rod 51c, 51c of the two valves intake 51, 51, respectively, and the contact portions 72d1, 72d1 at the distal ends of the pair of arm portions 72d, 72d apart from the swing arm of the exhaust side 72 rest on the upper ends of rod 52c, 52c of the two exhaust valves 52, 52, respectively.

The swinging arms of the intake side and of exhaust side 71, 72 perform oscillating movement around its mounting and support portions with respect to the arm axes swing 7, 7 mentioned above when the rollers 71f, 72f at the distal ends of your arm portions are pushed by leaning against the valve eccentrics 61, 62 due to the rotation of the valve eccentrics 61, 62 following the rotation of the camshaft 6, and actuate the two valves respectively intake 51, 51 or the two exhaust valves 52, 52 at opening and closure by contact of contact portions 71d1, 71d1, 72d1, 72d1 of the other paired arm portions 71d, 71d, 72d, 72d against the upper ends of valve stem 51c, 51c, 52c, 52c.

The drive to open and close the intake and exhaust valves 51, 52 is carried out by means of cooperating actions of the valve opening due to the thrust of rollers 71f, 72f on valve eccentrics 61, 62 and of the elastic lifting forces exerted by the springs of valve 51d, 52d to close the intake and exhaust valves 51, 52

As described above, the mechanism of valve A above cylinder head 3 is covered by the cylinder head cover 4 fixed to cylinder head 3. How to depicted in figure 4, on the cylinder head cover 4 has been formed integrally a top wall portion 4a having a shape substantially rectangular exterior as seen in plan view, and a side wall portion 4b of a predetermined width formed at its peripheral edge and that extends substantially perpendicular to the upper wall portion 4a. The cover of stock 4 has a bowl-like shape of a depth default together. Therefore, the space surrounded by the upper portion of the cylinder head 3, the wall portion top 4a of the cylinder head cover, and the side wall portion 4b of the cylinder head cover define a chamber (valve chamber) for valve mechanism A.

The cylinder head cover 4 is provided with threaded holes 4e to attach the cylinder head cover 4 to the cylinder head of cylinder 3. In addition, the two motion regulating elements 4c, 4d described above are provided on the inner surface of the upper wall portion 4a of the cylinder head cover, i.e. on the inner surface of the portion that forms the surface substantially lower of the bowl-shaped structure. The motion regulating elements 4c, 4d are formed as protrusions of a predetermined width protruding a height Default of the inner surface. The two outgoing are arranged at a predetermined distance from each other.

As depicted in Figures 4 to 6, the 4c, 4d motion regulating elements in the form of two protrusions of a predetermined width have substantially the Same height and width. The movement regulator element 4c is planned in a position on the inner surface of the portion top wall 4a of the cylinder head cover that is located to the left side with respect to the longitudinal direction and slightly to the lower side with respect to the direction lateral as seen in the plan view represented in the figure 4. The other 4d motion regulator element is provided in a position on the inner surface of the wall portion upper 4a of the cylinder head cover that is located substantially in the center with respect to the direction longitudinally and slightly to the upper side with respect to the lateral direction as seen in the plan view represented in Figure 4

\hbox{directo con los
ejes de brazo oscilante 7, 7 al montar la cubierta de culata
4.}

In addition, the movement regulator elements 4c, 4d are positioned such that when the cylinder head cover 4 is attached to the cylinder head 3, the movement regulator element 4c is located in a position corresponding to an oscillating arm axis 7, that is, the oscillating arm axis of the intake side 7, and the other motion regulating element 4d is located in a position corresponding to the other axis of the oscillating arm 7, that is, the oscillating arm axis of the exhaust side 7. Accordingly, the motion regulating elements 4c, 4d are provided, respectively, with recessed concave portions 4c1, 4d1 (see Figures 3, 5) at the distal ends of their protruding portions to avoid contact

 \ hbox {direct with the
swing arm shafts 7, 7 when mounting the cylinder head cover
4.} 

The two motion regulating elements 4c, 4d provided in the above mentioned positions on the surface inside of the upper wall portion 4a of the cover of stock serve to regulate the movement of the swinging arms respective 71, 72, which are mounted and supported on the two axes of swing arm 7, 7 mentioned above, on the axes of swing arm 7, 7 to place it. The elements 4a, 4d motion regulators are facing the ends distal 71e1, 72e1 of the projections described above 71e, 72e, which they are formed as the extended portions of the portions overhangs of the main body portions of swing arm 71a, 72a, with a slight interval between (see Figure 1).

The internal combustion engine E according to the embodiment of the present invention is generally constructed as It has been described above. With the internal combustion engine E, when the fuel-air mixture ignites supplied to the combustion chamber 3a, the fuel experiences explosive combustion so that the piston P is press through the resulting combustion energy; the Depression of the piston P rotates the crankshaft 1a through the connecting rod 1d, and the rotation of the crankshaft 1a raises the piston P by the connecting rod 1d, so that the piston P alternates. The alternative movement of P piston and crankshaft rotation 1a drive to open and close the intake valve 51 and the valve exhaust 52 by rotating the camshaft 6 in a default sequence and in a predetermined time synchronized with the alternative movement and rotation mentioned previously.

During combustion engine operation internal E as described above, the two eccentrics of valve 61, 62, whose eccentric threads move in position of each other with respect to the direction of rotation of the camshaft 6, respectively rest against rollers 71f, 72f attached to the distal ends of the respective portions of arm 71c, 72c of the two oscillating arms 71, 72; the rotation of the eccentric valve 61, 62 following the rotation of the shaft of cams 6 raises the respective arm portions 71c, 72c of swinging arms 71, 72 at a predetermined time, making that the swinging arms 71, 72 swing around the axis of swing arm 7 as its center of tilt, and arms oscillating 71, 72 lower the upper ends of rod of valve 51c, 52c by means of contact portions 71d1, 72d1 at the distal ends of its other arm portions 71d, 72d, thereby actuating the intake and exhaust valves 51, 52 of so that they open and close in a predetermined sequence and to a predetermined time

In addition, when, during the operation of the swing arms 71, 72 as described above, the swinging arms 71, 72 move against the elastic forces of the pressure springs 81, 82 due to the forces that make them move in the axial direction of the swing arm axis 7, this movement is regulated immediately by contact of the distal ends 71e, 72e1 of the projections 71e, 72e, which are the axially extended portion of the upper portion of the portions of main body of swing arm 71a, 72a, against motion regulating elements 4c, 4d in the form of projections on the inner surface of the upper wall portion 4th of the cylinder head cover. Therefore, the movement of swing arm shafts 71, 72 in the axial direction of the shaft swing arm 7 against spring elastic forces 81, 82 during the swinging of the axle shafts Oscillating 71, 72 is almost completely limited.

The embodiment of the present invention, which is build as described above, provide the following effects.

Cylinder head cover 4 is provided with 4c, 4d motion regulating elements to regulate the axial movement of the swinging arms 71, 72 against the forces spring springs 81, 82 in the state where the deck of cylinder head 4 is mounted on cylinder head 3. Therefore, the axial movement of the oscillating arms 71, 72 can be effectively limited without causing the pressure loads of the springs 81, 82 to limit the axial movement of the arms oscillating 71, 72 are unnecessarily large, so the previous movement can be limited within an appropriate range even when vibration occurs during the operation of the engine.

In addition, the proper regulation of the loads of pressure exerted by springs 81, 82 eliminates the difficulty of axial movement of the swinging arms 71, 72 at the time of regulate the free space of the pusher. This facilitates the swing arm movement 71, 72 at the time of adjustment, making it possible therefore to facilitate the regulation operation and achieving an improvement in workability. In addition, the movement of the swing arms 71, 72 on the swing arm axes 7, 7 is  possible by simply removing the cylinder head cover 4, and this movement is easily effected, so the adjustment operation of the wedge is facilitated by improving the workability

The swinging arms 71, 72 have the projections 71e, 72e oriented in the axial direction and protruding  in the radial direction, and the movement regulating elements 4c, 4d come into contact with the projections 71e, 72e. The contact between the swinging arms 71, 72 and the regulating elements of 4c, 4d movement can easily be done without being hindered by other elements such as springs 81, 82. By consequently, the oscillating movement of the oscillating arms 71, 72 to operate the intake and exhaust valves 51, 52 results stable without hardly involving any (lateral) movement in the axial direction of the oscillating arm axes 7, 7, which contributes considerably not only to the reliable drive to open and close the intake and exhaust valves 51, 52, but also to reduced noise and vibration of the internal combustion engine E.

The movement regulating elements 4c, 4d provided on the inner surface of the upper wall portion 4a of the cylinder head cover 4 are respectively opposite different oscillating arm axes 7, 7. The positions where the motion regulating elements 4c, 4d are in front of the swing arm shafts 7, 7 are respectively set as different axial positions of the oscillating arm axes 7, 7. Consequently, the charges to be introduced into the elements 4c, 4d motion regulators via arm axes oscillating 7, 7 are dispersed, so that the load imposed on the cylinder head cover 4 in terms of resistance can be reduced from way that is relatively low, and there is no need to take measures to significantly increase the resistance of the cylinder head cover 4.

The movement regulating elements 4c, 4d they are formed integrally with the cylinder head cover 4, and have in its distal end portions the concave portions 4d1, 4d1 lowered along the swing arm axes 7, 7. By consequently, the motion regulating elements 4c, 4d are they can approximate the swing arm axes 7, 7 as much as possible while ensuring a free space between them and the axes of oscillating arm 7, 7, and the swing arm movement 71, 72. In addition, the elements 4a, 4d motion regulators can be prepared cheaply due to its integral formation with the cylinder head cover 4.

It should be noted that although in the realization described above the motion regulating elements 4c, 4d se formed integrally with the cylinder head cover 4, can also be form separately from the cylinder head cover 4. In addition, the motion regulating elements 4c, 4d can be formed by elements that have the appropriate elasticity.

Claims (3)

1. An internal combustion engine including: a valve chamber formed by a cylinder head cylinder and a cylinder head cover; Y an oscillating arm oscillatingly supported and axially movable in a swing arm axis arranged in the valve chamber, the swing arm being pushed axially by an elastic element, where the cylinder head cover includes an element regulator to regulate the axial movement of the swing arm in a state where the cylinder head cover is mounted on the cylinder head of cylinder. 2. The internal combustion engine according to the claim 1, wherein: the swing arm has a protrusion that excels radially; Y the regulatory element contacts the projection. 3. The internal combustion engine according to the claim 1 or 2, wherein the regulatory element is formed integrally with the cylinder head cover, and has in its portion of distal end a concave portion recessed along the axis of swing arm.