JP2010144621A - Valve gear for overhead valve type engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a valve gear for an overhead valve type engine including a lateral vibration regulation means positively and sufficiently suppressing the lateral vibration of a rocker arm and having superior cost performance that can rationally correspond even when an inexpensive rocker arm made of a sheet metal is adopted. <P>SOLUTION: In this valve gear 1 for the overhead valve type engine including the rocker arm 20 rockably supported by a spherical crown bearing 30, as the lateral vibration regulation means for regulating undesired lateral vibration occurring in the rocker arm 20 in the direction orthogonal to a rocking direction, a guided part 27 such as a guided hole, a guided groove, or a guided inner wall is provided to the rocker arm 20, and a pin 51 as a guiding member is fixed to a fixed part in a valve gear chamber to which the guided part 27 comes in contact with. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a valve operating apparatus for an overhead valve type engine having a rocker arm supported in a swingable manner by a ball crown bearing, and more particularly, to a direction perpendicular to the swinging direction (vertical direction) generated in the rocker arm. The present invention relates to a valve operating apparatus for an overhead valve engine provided with a lateral vibration regulating means for regulating a desired lateral vibration (rotation).

  2. Description of the Related Art Conventionally, as a valve operating device for an overhead valve type engine, a type in which a rocker arm is swingably supported by a spherical crown bearing as known in, for example, Patent Document 1 below is known.

  In this type of valve gear, the spherical surface of the end of the push rod is normally brought into contact with one end of the rocker arm (spherical recess) supported so as to be swingable by a spherical crown bearing and simultaneously pushes up the one end. The spherical portion at the other end abuts on the intake / exhaust valve (the upper end of the stem) and pushes it down.

  In such a valve operating apparatus, the rocker arm is swingably supported by the spherical crown bearing, and as described above, one end portion is pushed up by the end spherical portion of the push rod, and the intake / exhaust valve is provided by the spherical portion of the other end portion. Because of the push-down, undesired lateral vibration (rotation) tends to occur in a direction perpendicular to the rocking direction (vertical direction) of the rocker arm.

  Such undesired lateral vibration (rotation) tends to cause uneven wear on the rocker arm, intake / exhaust valves, etc., leading to problems such as a decrease in durability, a decrease in output, and an increase in noise. It was.

  Therefore, conventionally, as described in, for example, Patent Document 2 below, the side guide member is used as a valve spring plate of the intake / exhaust valve as a lateral vibration regulating means for regulating unwanted lateral vibration generated in the rocker arm. It has been proposed to form one piece.

  Patent Document 3 below proposes to form a guide elongated hole through which a push rod is passed through a cylinder (gasket or the like) as the lateral vibration regulating means.

Japanese Utility Model Publication No. 63-118309 JP 2002-106311 A Japanese Utility Model Publication No. 6-22085

  However, the lateral shake restricting means as described in Patent Documents 2 and 3 do not sufficiently suppress the lateral shake of the rocker arm, and the rocker arm, valve spring plate, cylinder (gasket), etc. There is a problem that the manufacturing cost is high.

  On the other hand, in order to reduce the cost of the valve operating device, it is considered that the rocker arm is made of sheet metal. However, the lateral vibration regulation with excellent cost performance is reasonably compatible with this inexpensive sheet metal rocker arm. I still have no means.

  The present invention has been made in view of the above circumstances, and the object of the present invention is to sufficiently suppress the lateral swing of the rocker arm, even when an inexpensive sheet metal rocker arm is employed. It is an object of the present invention to provide a valve operating apparatus for an overhead valve type engine equipped with a lateral vibration regulating means excellent in cost performance that can be reasonably handled.

  In order to achieve the above object, a valve operating apparatus for an overhead valve type engine according to the present invention basically has a rocker arm swingably supported by a spherical crown bearing, and is generated in the rocker arm. The rocker arm is provided with a guided portion such as a guided hole, a guided groove, or a guided wall as a lateral vibration regulating means for regulating unwanted lateral vibration in a direction orthogonal to the swing direction. In addition, a guide member that contacts the guided portion is fixed to a non-moving portion in the valve operating chamber.

  The rocker arm is preferably made of sheet metal, and is preferably manufactured in a cross-sectional groove shape.

  In a preferred specific embodiment, the rocker arm is provided with a long hole or groove as the guided portion in parallel with the rocking surface, and slides in the long hole or groove in the non-moving portion of the valve operating chamber. A pin as the guide member that is freely inserted is fixed.

  In another preferred specific embodiment, at least one of both side walls of the rocker arm manufactured in a cross-sectional groove shape is used as the guided portion, and as the guide member, at least one of the side walls. A member having an inverted U-shaped groove or bent portion that is guided so as to sandwich one side is used.

The guide member is preferably made of sheet metal.
In another preferred embodiment, a displacement preventing member for preventing the guide member from bending, swinging, displacement, or the like is provided.

  In another preferred embodiment, the intake / exhaust valve has a pair of rocker arms, and the guided portion and the guide member are provided for the pair of rocker arms, respectively.

  In another preferred aspect, the guided portion, the guide member, and the displacement prevention member are provided for the pair of rocker arms, respectively, and the pair of guide members and the displacement prevention member are integrated. And

  In the valve operating apparatus for an overhead valve type engine according to the present invention, the rocker arm is provided with guided portions such as guided holes, guided grooves, or guided walls as lateral vibration regulating means, Since a guide member such as a pin that contacts the guided portion is fixed to the non-moving portion, the rocker arm swings when the engine is operated, and the guided portion provided on the rocker arm is moved to the guide member. Moves up and down while sliding. Accordingly, the lateral swing of the rocker arm can be surely and sufficiently suppressed, and it is possible to rationally cope with an inexpensive sheet metal rocker arm that has been difficult to employ.

  In addition, a guided portion such as a long hole is provided in an existing rocker arm, and the guide member such as a pin into which the long hole is slidably inserted is fixed to a cylinder head (bottom of the valve operating chamber) ( It only needs to be planted), so it has excellent cost performance.

  Embodiments of a valve operating apparatus for an overhead valve engine according to the present invention will be described below with reference to the drawings.

  1 to 7 schematically show an embodiment (Examples 1 to 7) of a valve operating apparatus for an overhead valve type engine according to the present invention.

  The valve gears of the first to seventh embodiments basically include a pair of left and right rocker arms 20 and 20 for opening and closing the intake and exhaust valves 17 and 17 disposed symmetrically with respect to the center line C. It is of a type that is supported by the ball bearings 30 and 30 so as to be swingable. The rocker arm 20 is made of sheet metal and is manufactured in a cross-sectional groove shape having a bottom wall 21 and left and right side walls 22a and 22b. Near the central portion of the bottom wall 21, a spherical recess 21 a having a circular or oval opening 26 in a plan view that contacts the spherical portion 30 a of the spherical crown bearing 30 is formed. The spherical crown bearing 30 is fixed to the cylinder head 12 vertically by bolts and nuts 32 (center axis O), and one end portion (spherical shape) of the rocker arm 20 supported by the spherical crown bearing 30 so as to be swingable. The upper spherical surface portion 16 of the push rod 15 is loosely fitted into the concave portion 23) to push up one end thereof, and at the same time, the spherical convex portion 24 at the other end abuts against the intake / exhaust valve 17 (the upper end portion of the stem). Is to be pushed down. Although not shown, the intake / exhaust valve 17 is always urged upward (in the valve closing direction) by a coil spring that is compressed between the cylinder head 12 (the bottom of the valve operating chamber) and the spring receiver 18. ing. Further, the rocker arm 20 has the other end portion (spherical convex portion 24) on the intake / exhaust valve 17 side slightly shifted to the center line C side, and the pair of rocker arms 20 and 20 has the center line C as a center line. They are arranged symmetrically in a plan view.

  In such a valve operating apparatus, the rocker arm 20 is swingably supported by the spherical crown bearing 30, and the one end (spherical concave portion 23) is pushed up by the upper end spherical portion 16 of the push rod 15 and the other end as described above. Since the spherical convex part 24 of the part pushes down the intake / exhaust valve 17, undesired lateral vibration occurs in a direction perpendicular to the rocking direction (vertical direction) of the rocker arm 20.

In the present embodiment (Examples 1 to 7), there is provided a lateral vibration restricting means for restricting an undesirable lateral vibration generated in the rocker arm 20 in a direction orthogonal to the swing direction (vertical direction). .
Hereinafter, the lateral shake regulating means of each embodiment will be described.

[Example 1: FIG. 1]
In the first embodiment, the rocker arm 20 is provided with a long hole 27 as a guided portion, and the long hole 27 is slidably inserted into the cylinder head 12 which is a non-moving portion as a lateral vibration restricting means. A pin 51 as a guide member is fixed (planted) vertically in the vertical direction. Here, the elongated hole 21 is a center connecting the center of one end portion (spherical concave portion 23) of the rocker arm 20, the center axis O of the spherical crown bearing 30, and the center of the other end portion (spherical convex portion 24). The length of the pin 51 is set so as not to prevent the rocker arm 20 from swinging (the front and rear ends thereof do not contact the pin 51). It is set slightly shorter than the width of the hole 21.

  In the valve operating apparatus 1 of the present embodiment provided with the lateral swing restricting means having such a configuration, the rocker arm 20 swings during engine operation, and the long hole 27 provided in the rocker arm 20 is provided on the pin 51 as a guide member. Moves up and down while sliding. As a result, it is possible to reliably and sufficiently suppress the lateral swing of the rocker arm 20 and to rationally cope with an inexpensive sheet metal rocker arm that has been difficult to employ.

  Moreover, since the long hole 27 is provided in the existing rocker arm and the pin 51 only needs to be fixed (planted) to the cylinder head 12 (bottom of the valve operating chamber), the cost performance is excellent.

[Example 2: FIG. 2]
In the second embodiment, one side wall 22a (center line C side) of the rocker arm 20 having a cross-sectional groove shape is used as a guided portion, and as a guide member, the cross-section reversely guided so as to sandwich the side wall 22a. A bent plate material 53 made of sheet metal having a bent vertical piece portion 53a in which a U-shaped vertical groove 54 is formed is used. The bent plate material 53 is held and fixed by bolts and nuts 32 for fixing the spherical crown bearing 30 to the cylinder head 12.

  Further, in addition to providing the pair of rocker arms 20 and 20 with bent plate members 53 as guide members, the pair of bent plate members 53 and 53 are prevented from bending, swinging, displacement, and the like. Therefore, as a displacement prevention member that can also be used as a cooling air guide member, the thickness protrudes upward from the cylinder head 12 and the both end surfaces thereof are in contact with the one side walls 22a and 22a of the bent plate members 53 and 53, respectively. A plate-like wall portion 55 is provided.

  In the valve operating apparatus 2 of the present embodiment provided with the lateral swing restricting means having such a configuration, the rocker arm 20 swings during the engine operation, and the rocker arm 20 side wall 22a is bent at the bent plate member 53 as a guide member. It moves up and down while sliding in contact with the vertical groove 54 formed in the vertical piece 53a. As a result, it is possible to reliably and sufficiently suppress the lateral swing of the rocker arm 20 and to rationally cope with an inexpensive sheet metal rocker arm that has been difficult to employ.

  Further, since it is only necessary to add the bent metal plate 53 to the existing rocker arm, the cost performance is excellent.

[Example 3: FIG. 3]
In this third embodiment, a pair of bent plate members 53, 53 having the same configuration as in the second embodiment is integrated, and the integrated bent plate material 56 (the bridge portion thereof) is a displacement prevention member (of the second embodiment). It is intended to work as a thick plate-like wall portion 55).

  Thereby, substantially the same operation effect as Example 2 can be obtained, and the number of parts can be reduced.

[Example 4: FIG. 4]
In the fourth embodiment, one side wall 22a of a pair of rocker arms 20 and 20 is used as a guided portion, and a folding member having an inverted U-shaped cross section that guides the side walls 22a and 22a as a guide member. One bent plate material 57 made of sheet metal having curved portions 58 and 58 is used. The bent plate member 57 is held and fixed by a pedestal 35 and bolts 36 provided between the pair of rocker arms 20 and 20 on the cylinder head 12.
In the fourth embodiment, the same effects as those of the second and third embodiments can be obtained.

[Example 5: FIG. 5]
In the fifth embodiment, similarly to the fourth embodiment, one side wall 22a of the pair of rocker arms 20 and 20 is used as a guided portion, and the side walls 22a and 22a are guided as a guide member. A bent metal plate 63 made of sheet metal having a bent vertical piece 63a formed with a vertical groove 64 having an inverted U-shaped cross section is used. The bent plate 63 is held and fixed by a pedestal 35 and bolts 36 provided between the pair of rocker arms 20 and 20 on the cylinder head 12.
Also in the fifth embodiment, substantially the same function and effect as in the second, third, and fourth embodiments can be obtained.

[Example 6: FIG. 6]
In the sixth embodiment, as the lateral swing restricting means, a bent protrusion 28 that is bent and protrudes in the horizontal direction is provided on one side wall 22a of the rocker arm 20 having a groove shape in cross section. A U-shaped lateral groove 29 as a guided portion is formed in the shaft, and a pin 51 as a guide member into which the groove 28 is slidably fitted into the cylinder head 12 as a non-moving portion is fixed vertically in the vertical direction. (Planted).
Also in the sixth embodiment, substantially the same operational effects as in the first embodiment can be obtained.

[Example 7: FIG. 7]
The seventh embodiment is a combination of the first and second embodiments. A long hole 27 is provided as a guided portion, and the long hole 27 is slidably inserted into the cylinder head 12 as a guide member. The pin 51 is fixed (planted) vertically in the vertical direction, and the side wall 22a is used as a guided portion, and a vertical groove having an inverted U-shaped cross section that guides the side wall 22a as a guide member. A bent plate material 53 made of sheet metal having a bent vertical piece portion 53 a formed with 54 is used. In order to suppress the deflection of the pin 51, an extension pressing portion 53 b is extended on the bent plate material 53, and the extension pressing portion 53 b is fixed to the upper end surface of the pin 51 by welding or the like. The bent plate material 53 is held and fixed by bolts and nuts 32 for fixing the spherical crown bearing 30 to the cylinder head 12.

  Further, as a displacement prevention member that can also be used as a cooling air guide member in order to prevent bending, swinging, displacement, etc. of the pair of bent plate members 53, 53, it protrudes upward from the cylinder head 12 and its both end faces Thick plate-like wall portions 55 are provided to abut on the surfaces of the side walls 22a and 22a of the bent plate materials 53 and 53, respectively.

  Also in the seventh embodiment, substantially the same function and effect as the above-described embodiments can be obtained.

1 shows Embodiment 1 of a valve operating apparatus for an overhead valve type engine according to the present invention, in which (A) is a plan view and (B) is a cross-sectional view taken along the line XX of (A). FIG. 3 shows a second embodiment of the valve operating system for an overhead valve engine according to the present invention, in which (A) is a plan view and (B) is a cross-sectional view taken along line YY of (A). Embodiment 3 of the valve operating apparatus for an overhead valve type engine according to the present invention is shown, (A) is a plan view, and (B) is a cross-sectional view taken along line YY of (A). FIG. 4 shows a valve operating apparatus for an overhead valve engine according to a fourth embodiment of the present invention, in which (A) is a plan view and (B) is a cross-sectional view taken along the line ZZ of (A). Embodiment 5 of the valve operating apparatus for an overhead valve type engine according to the present invention is shown, (A) is a plan view, and (B) is a sectional view taken along the line ZZ of (A). The top view which shows Example 6 of the valve operating apparatus of the overhead valve type engine which concerns on this invention. The top view which shows Example 7 of the valve operating apparatus of the overhead valve type engine which concerns on this invention.

Explanation of symbols

1 Valve operating device 10 Engine (cylinder)
12 Cylinder head 15 Push rod 17 Intake / exhaust valve 20 Rocker arm 21 Bottom wall 22a, 22b Side wall 27 Slot (guided part)
30 Ball bearing 51 Pin (Guide member)
53, 56, 57 Bent plate material (guide member)
54 Vertical groove 58 Reverse U-shaped bent part (guide part)
55 Thick plate wall (displacement prevention member)

Claims (9)

  A valve operating apparatus for an overhead valve type engine having a rocker arm swingably supported by a ball crown bearing, in order to restrict undesired lateral vibration in the direction perpendicular to the rocking direction generated in the rocker arm. As a lateral vibration restricting means, the rocker arm is provided with a guided portion such as a guided hole, a guided groove, or a guided wall, and is in contact with the guided portion at a non-moving portion in the valve operating chamber. A valve operating apparatus for an overhead valve type engine, wherein a guide member is fixed.   The valve operating apparatus for an overhead valve engine according to claim 1, wherein the rocker arm is made of sheet metal.   The valve operating device for an overhead valve engine according to claim 1 or 2, wherein the rocker arm is manufactured to have a cross-sectional groove shape.   The guide rocker arm is provided with an elongated hole or groove as the guided portion in parallel with the swinging surface, and is slidably fitted into the elongated hole or groove in the stationary portion of the valve operating chamber. 4. The valve operating apparatus for an overhead valve engine according to claim 1, wherein a pin as a member is fixed. 5.   At least one of both side walls of the rocker arm manufactured in a cross-sectional groove shape is used as the guided portion, and the guide member is guided so as to sandwich at least one of the both side walls. 4. A valve operating apparatus for an overhead valve engine according to claim 3, wherein a member having a letter-shaped groove or bent portion is used.   6. The valve operating apparatus for an overhead valve engine according to claim 5, wherein the guide member is made of sheet metal.   The valve operating apparatus for an overhead valve type engine according to any one of claims 1 to 6, further comprising a displacement prevention member for preventing the guide member from bending, swinging, displacement, and the like.   8. A pair of rocker arms for intake and exhaust valves, wherein the guided portion and the guide member are provided for the pair of rocker arms, respectively. The valve operating device of the described overhead valve type engine.   9. The guided portion, the guide member, and the displacement prevention member are provided for the pair of rocker arms, respectively, and the pair of guide members and the displacement prevention member are integrated. The valve operating device of the described overhead valve type engine.

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