JP2007071131A - Valve gear of engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To miniaturize a valve gear by avoiding lengthening of a second rocker arm by avoiding interference of at least one of a roller support part of a first rocker arm and a roller with a boss part even if a sliding surface is arranged in close vicinity to a support shaft for slidably supporting the boss part of the second rocker arm. <P>SOLUTION: This valve gear of an engine is constituted by pivoting the roller getting into rolling contact with a valve system cam of a camshaft via a roller shaft to the roller support part arranged in the first rocker arm, having the cylindrical boss part rotatably supported by the support shaft and a sliding surface for slinding contact with the roller shaft, interlocking and connecting the second rocker arm having an arm part extended from the boss part with and to an engine valve, and displacing any one of the rocking axis of the first and second rocker arms in a plane orthogonal to the axis of the camshaft. Cutout parts 52 and 53 for avoiding interference with at least one of the roller support part 38 of the first rocker arm 23 and the roller 25, are arranged in the boss part 45 of the second rocker arms 26A and 26B. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  According to the present invention, a camshaft provided with a valve cam, a first rocker arm swingable about a first axis parallel to the axis of the camshaft, and a roller support provided on the first rocker arm via a roller shaft. The roller that is pivotally supported and is in rolling contact with the valve cam, the cylindrical boss portion that is rotatably supported by a support shaft having a second axis parallel to the first axis, and the roller shaft are in sliding contact with each other. A second rocker arm having an arm portion extending from the boss portion and coupled to and coupled to the engine valve, and one of the first and second axes is connected to the camshaft. The present invention relates to a valve gear for an engine that is displaced in a plane perpendicular to an axis.

Such a valve operating apparatus for an engine is already known from Japanese Patent Application Laid-Open No. 2003-260260.
JP 2001-164911 A

  However, in the one disclosed in Patent Document 1, the outer peripheral surface of the boss portion provided in the second rocker arm remains cylindrical, and the roller and the roller shaft that supports the roller in the first rocker arm are supported. In order to avoid interference with the boss portion, the sliding surface of the second rocker arm must be separated from the boss portion, so that the second rocker arm becomes longer and the valve operating device becomes larger. Connected to.

  The present invention has been made in view of such circumstances, and an object thereof is to provide an engine valve operating apparatus that can be downsized.

  In order to achieve the above object, a first aspect of the present invention includes a camshaft provided with a valve cam, a first rocker arm that can swing about a first axis parallel to the axis of the camshaft, A roller support portion provided on the rocker arm is pivotally supported via a roller shaft and is rotatably supported by a roller that is in rolling contact with the valve cam and a support shaft having a second axis parallel to the first axis. A first boss portion having a cylindrical boss portion and a second rocker arm having a sliding surface for slidingly contacting the roller shaft and having an arm portion extending from the boss portion and interlocked and coupled to the engine valve; In the valve operating apparatus for an engine in which either one of the second axis and the second axis is displaced in a plane perpendicular to the axis of the camshaft, the low boss of the first rocker arm is placed on the boss of the second rocker arm. Wherein the notch to avoid interference with at least one of the support portion and the roller are provided.

  According to a second aspect of the present invention, in addition to the configuration of the first aspect of the present invention, the boss portion is provided with a notch portion that avoids interference with the roller and the roller support portion.

  According to a third aspect of the invention, in addition to the configuration of the first aspect of the invention, the notch is formed so as to expose a part of the outer peripheral surface of the support shaft.

  Furthermore, the invention according to claim 4 is characterized in that, in addition to the configuration of the invention according to claim 3, an oil guide surface connected to the notch is formed on the second rocker arm so as to face upward.

  According to the first aspect of the present invention, even if the sliding surface is disposed in the vicinity of the pivot shaft that supports the boss portion of the second rocker arm so as to be swingable, at least one of the roller support portion and the roller of the first rocker arm. Can be prevented from interfering with the boss portion, and the length of the second rocker arm can be set short to contribute to the downsizing of the valve gear.

  According to the second aspect of the present invention, it is possible to prevent the roller support portion and the roller of the first rocker arm from interfering with the boss portion so that the sliding surface can be brought close to the support shaft. The length can be set shorter to contribute to the miniaturization of the valve gear.

  According to the third aspect of the present invention, it is possible to guide oil from the notch portion between the support shaft and the boss portion by exposing a part of the outer peripheral surface of the support shaft, and the second rocker arm and the support shaft. The lubrication can be performed well.

  According to the fourth aspect of the present invention, the oil can be guided to the notch portion by the oil guide surface, so that the lubrication between the second rocker arm and the support shaft can be performed more efficiently.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on examples of the present invention shown in the accompanying drawings.

  FIGS. 1 to 9 show a first embodiment of the present invention. FIG. 1 is a plan view of the valve operating apparatus, and FIG. 2 is a plan view of the valve operating apparatus in a state where the control shaft and the first rocker arm are omitted. 3 is a sectional view taken along line 3-3 in FIG. 1, FIG. 4 is a sectional view taken along line 4-4 in FIG. 1, FIG. 5 is a sectional view taken along line 5-5 in FIG. FIG. 7 is a sectional view showing the maximum lift state (a) and the minimum lift state (b) along the line 7-7 in FIG. 1, and FIG. 8 is the maximum lift state (a) and the minimum lift state (b). FIG. 9 is a cross-sectional view taken along line 8-8 in FIG. 1, and FIG. 9 is a diagram showing lift characteristics of both intake valves with the first intake valve (a) and the second intake valve (b).

  First, in FIGS. 1 to 3, this valve operating apparatus includes a camshaft 22 provided with a valve operating cam 21 common to a pair of engine valves, for example, the first and second intake valves V 1 and V 2, and an axis of the camshaft 22. A first rocker arm 23 swingable around a parallel first axis C1 and roller support portions 38, 38 provided on the first rocker arm 23 are pivotally supported via a roller shaft 24 and are in rolling contact with the valve cam 21. The roller 25 and the sliding surfaces 48A and 48B for slidingly contacting the roller shaft 24 are individually linked and connected to both the intake valves V1 and V2 and around the second axis C2 parallel to the first axis C1. And a pair of second rocker arms 26A, 26B that can rotate, and in this embodiment, the first axis C1 is the camshaft 2 in either one of the first and second axes C1, C2. It is displaceable in a plane perpendicular to the axis.

  In FIG. 4, the cylinder head 28 of the engine is provided with an intake port 29 and a pair of intake valve ports 30 communicating with the intake port 29, and the first and first intake valves 30 can be opened and closed. The stem portions 31 of the two intake valves V1 and V2 are slidably fitted to the guide cylinders 32 provided on the cylinder head 28, and are provided at the ends of the stem parts 31 protruding from the guide cylinders 32. Between the retainer 33 and the cylinder head 28, valve springs 34 for urging the first and second intake valves V1 and V2 toward the valve closing side are contracted.

  The cylinder head 28 is provided with holders 35, 35... Disposed on both sides of the first and second intake valves V 1, V 2, and the camshaft 22 is rotatably supported by these holders 35, 35. The The first rocker arm 23 is disposed between the holders 35, 35, and is spaced apart in a direction along the axis of the camshaft 22 and a pair of first arms along a plane perpendicular to the axis of the camshaft 22. And a movable support shaft 37 that has a first axis C1 and connects the base ends of the first arm portions 36, 36, and is provided at the distal ends of the first arm portions 36, 36. Both end portions of the roller shaft 24 are supported between the circular roller support portions 38, 38 provided respectively.

  In the first rocker arm 23, both ends of the movable support shaft 37 protrude outward from the first arm portions 36, 36, and both ends of the movable support shaft 37 are supported by a control shaft 39 so as to be rotatable. Is done. The control shaft 39 has webs 39 a and 39 a disposed between the first arm portions 36 and 36 of the first rocker arm 23 and the pair of holders 35 and 35, and an axis parallel to the movable support shaft 37. A connecting shaft 39b for connecting the webs 39a and 39a; and rotating shafts 39c and 39d having an axis parallel to the connecting shaft 39b and connected to the outer surfaces of the webs 39a and 39a. The rotation shafts 39c and 39d are rotatably supported by the holders 35 and 35. In addition, the roller shaft 24 is configured so that the both roller support portions are coaxial with the axes of the rotation shafts 39c and 39d of the control shaft 39 when the first and second intake valves V1 and V2 are in the closed seating state. 38 and 38.

  Both end portions of the movable support shaft 37 provided in the first rocker arm 23 pass through short cylindrical spacers 40, 40 interposed between the first arm portions 36, 36 of the first rocker arm 23 and the webs 39a, 39a. The two webs 39a and 39a are rotatably supported. Further, an actuator (not shown) for rotating the rotation shaft 39d is connected to one of the rotation shafts 39c, 39d, and the control shaft 39 is connected to the rotation shafts 39c, 39d by the actuator. By being driven to rotate about this axis, the movable support shaft 37 of the first rocker arm 23, that is, the first axis C1, rotates about the axis of the rotation shafts 39c and 39d.

  The roller 25 is pivotally supported at the central portion of the roller shaft 24 with an equal interval between the pair of roller support portions 38, 38, and a pair of retaining rings for determining the axial position of the roller 25. 41 and 41 are attached to the roller shaft 24 on both sides of the roller 25.

  The pair of second rocker arms 26A and 26B basically has a substantially symmetrical shape with respect to a plane passing through the axial center of the roller 25, and corresponds to the first intake valve V1 hereinafter. One second rocker arm 26A will be described in detail, and the other second rocker arm 26B corresponding to the second intake valve V2 is one second rocker arm 26A except for a portion different from the one second rocker arm 26A. The portions corresponding to are only shown with the same reference numerals, and the detailed description is omitted.

  One second rocker arm 26A is disposed below the first rocker arm 23, and has a cylindrical boss portion 45 rotatably supported by a fixed support shaft 44 having a second axis C2, and the boss portion. The second arm portion 46 extending from 45 and the valve connecting portion 47 provided at the tip of the second arm portion 46 to be linked and connected to the first intake valve V1 are integrally provided. A sliding surface 48A is provided on the upper surface of the roller shaft 24.

  The fixed support shaft 44 is fixedly supported by the holders 35, 35..., And the second arm portion 46 extends in a plane perpendicular to the second axis C2 of the fixed support shaft 44 so as to extend the boss. It is connected to the axially intermediate portion of the portion 45.

  The valve connecting portion 47 is connected to the distal end portion of the second arm portion 46 so as to protrude outward from the distal end of the second arm portion 46. Thus, the tappet screw 49 is screwed into the valve connecting portion 47 so that the advance / retreat position can be adjusted, and the tappet screw 49 abuts on the upper end of the stem portion 31 in the first intake valve V1. That is, the valve connecting portion 47 is linked and connected to the first intake valve V1 via the tappet screw 49.

  One second rocker arm 26A is connected to the outer surfaces of the valve connecting portion 47 and the second arm portion 46, and a portion of the boss portion 45 that protrudes outward from the second arm portion 46 and the second rocker arm 26A. A reinforcing wall portion 50 is provided to connect the outer surfaces of the two arm portions 46 so as to face the roller support portion 38 of the first rocker arm 23. In addition, the reinforcing wall portion 50 is formed on the opposite side of the roller shaft 24 so as to face the roller support portion 38 at a position retracted from the sliding surface 48A of the second arm portion 46.

  In FIG. 5, one second rocker arm 26 </ b> A is connected to the roller 25 by connecting a portion of the boss portion 45 that protrudes inward from the second arm portion 46 and the inner side surface of the second arm portion 46. Opposing reinforcing wall portions 51 are provided, and the reinforcing wall portions 51 are formed so as to face the roller 25 at a position retracted from the sliding surface 48 </ b> A on the side opposite to the roller shaft 24.

  Thus, the first rocker arm 23 disposed above one second rocker arm 26A is formed such that at least one roller support portion 38 overlaps one second rocker arm 26A in plan view. In the embodiment, most of the first rocker arm 23 is formed so as to overlap with one second rocker arm 26A in plan view.

  Referring also to FIG. 6, the boss portion 45 of one second rocker arm 26A avoids interference with at least one of the roller support portion 38 and the roller 25 of the first rocker arm 23, both in this embodiment. Notches 52 and 53 are provided, and both notches 52 and 53 are formed so as to expose a part of the outer peripheral surface of the fixed support shaft 44.

  In addition, the outer surfaces of the valve connecting portion 47 and the second arm portion 46 are connected, and the portion of the boss portion 45 that protrudes outward from the second arm portion 46 and the outer surface of the second arm portion 46 are connected. In this way, an oil guide surface 54 that continues to one of the cutout portions 52 is formed on a part of the upper surface of the reinforcing wall portion 50 provided on one of the second rocker arms 26A. Of the second arm portion 46 and the inner surface of the second arm portion 46 are connected to each other on the upper surface of the reinforcing wall portion 51 facing the second rocker arm 26A. An oil guide surface 55 connected to the notch 53 is formed facing upward.

  Incidentally, the contact point between the sliding surface 48A provided on the second arm portion 46 of the one second rocker arm 26A and the roller shaft 24 is such that the roller 25 is operated by the valve cam as shown in FIGS. An arc 56A passing through the contact point of the roller shaft 24 with the sliding surface 48A on the side separated from the fixed support shaft 44 when being in sliding contact with the base circle portion 21a, and centering on the first axis C1. The first intake valve V1 is lifted in the valve opening direction when the second rocker arm 26A is pushed downward by the movement of the roller shaft 24 along the arcs 56A and 56B.

  On the other hand, the movable support shaft 37 of the first rocker arm 23 is in the lower position when the control shaft 39 is at the maximum lift position shown in FIG. 7A and the control shaft 39 is in the minimum lift position shown in FIG. 7B. The sliding surface 48A of one second rocker arm 26A is in the minimum lift state shown in FIG. 7 (b) with respect to the sliding surface 48A of the second rocker arm 26A. It is formed so as to be at a position shifted from the arc 56B to the first axis C1 side. That is, even in the minimum lift state, the sliding surface 48A is formed so as to swing one of the second rocker arms 26A toward the side where the first intake valve v1 is lifted open.

  Moreover, an oil retaining recess 57A capable of retaining oil is formed on the sliding surface 48A of one second rocker arm 26A, and the oil retaining recess 57A is a plane perpendicular to the axis of the roller shaft 24. It is formed in a groove shape.

  The boss portion 45 of one second rocker arm 26A is provided with an oil discharge port 58 that opens toward the oil retaining recess 57A. Thus, an oil supply path 59 for supplying oil from an oil supply source (not shown) is provided in the fixed support shaft 44, and an annular recess 60 communicating with the oil discharge port 58 is provided on the outer periphery of the fixed support shaft 44. And a communication hole 61 that allows the annular recess 60 to communicate with the oil supply passage 59 is provided in the fixed support shaft 44. That is, oil is discharged from the oil discharge port 58 communicating with the oil supply path 59 in the fixed support shaft 44 toward the oil holding recess 57A.

  The other second rocker arm 26B has a sliding surface 48B and an oil retaining recess 57B different from the sliding surface 48A and the oil retaining portion 57A of the one second rocker arm 26A, except that the second arm portion 46 is provided with a sliding surface 48B. The second rocker arm 26A is constructed in the same manner as the one second rocker arm 26A, and the two rocker arms 26A, 26B are in contact with the inner ends of their boss portions 45, 45 so that they are below the first rocker arm 23. The distance between the sliding surfaces 48A and 48B of the second rocker arms 26A and 26B is set shorter than the distance between the first and second intake valves V1 and V2.

  In FIG. 8, the contact point between the sliding surface 48B provided on the second arm portion 46 of the other second rocker arm 26B and the roller shaft 24 is when the control shaft 39 is at the maximum lift position shown in FIG. In any state when the control shaft 39 is at the minimum lift position shown in FIG. 8B, the side separated from the fixed support shaft 44 when the roller 25 is in sliding contact with the base circle portion 21a of the valve cam 21. And moves along arcs 56A and 56B centered on the first axis C1 and passes along the arcs 56A and 56B of the roller shaft 24. When the other second rocker arm 26B is pushed downward by the movement, the second intake valve V2 is lifted in the valve opening direction.

  Moreover, the sliding surface 48B of the other second rocker arm 26B is formed so that the portion on the fixed support shaft 44 side is on the same curve as the arc 56B in the minimum lift state shown in FIG. 8B. That is, in the minimum lift state, the other second rocker arm 26B keeps the second intake valve V2 closed and seated.

  Thus, by forming the sliding surfaces 48A, 48B of the second rocker arms 26A, 26B so as to have mutually different shapes, the lift amount of the first intake valve V1 is the displacement of the first axis C1, that is, the control shaft. 9A changes as shown in FIG. 9A, whereas the lift amount of the second intake valve V2 changes as shown in FIG. 9 according to the displacement of the first axis C1, ie, the rotation of the control shaft 39. It changes as shown in (b), and it is between the maximum lift amount and the minimum lift amount of the second intake valve V2 compared to the lift amount difference ΔLA between the maximum lift amount and the minimum lift amount of the first intake valve V1. The lift amount difference ΔLB becomes smaller.

  In addition, the sliding surface 48B of the other second rocker arm 26B is formed with an oil retaining recess 57B capable of retaining oil in the shape of a groove in a plane perpendicular to the axis of the roller shaft 24. The concave portion 57B is formed so as to become gradually shallower toward the second axis C2 side, that is, toward the fixed support shaft 44 side.

  Next, the operation of the first embodiment will be described. At least the roller support portions 38, 38 of the first rocker arm 23 are arranged at positions overlapping the second rocker arms 26A, 26B in a plan view. The amount of displacement of the first rocker arm 23 in the direction along the axis of the camshaft 22 with respect to the second rocker arms 26A and 26B linked to and connected to the intake valves V1 and V2 is reduced, and the direction along the axis of the camshaft 22 is reduced. The valve gear can be miniaturized.

  Moreover, the distance between the sliding surfaces 48A and 48B of the pair of second rocker arms 26A and 26B individually corresponding to the first and second intake valves V1 and V2 is larger than the distance between the first and second intake valves V1 and V2. Since it is set to be small, the first and second rocker arms 23A and 26B can be arranged in any position in the direction along the axis of the camshaft 22 with respect to the sliding surfaces 48A and 48B of the first rocker arms 26A and 26B. Since the sliding surfaces 48A and 48B of the second rocker arms 26A and 26B are arranged in a range narrower than the interval between the second intake valves V1 and V2, the size of the valve operating device in the direction along the axis of the camshaft 22 is reduced. Can be achieved.

  The pair of second rocker arms 26A, 26B has a boss portion 45 that is rotatably supported by a fixed support shaft 44 having a second axis C2, and the boss portion 45 having the sliding surfaces 48A, 48B. A second arm portion 46 extending from the second arm portion 46, a valve connecting portion 47 extending outward from the tip of the second arm portion 46, and interlocked and connected to the first and second intake valves V1, V2, and a valve. The connecting portion 47 and the reinforcing wall portion 50 that connects the outer side surfaces of the second arm portions 46 are integrally formed, and the interval between the sliding surfaces 48A and 48B is smaller than the interval between the intake valves. As a result, in the second rocker arms 26A, 26B, the valve connecting portions 47 ... have to be arranged to project outward from the tips of the second arm portions 46 having the sliding surfaces 48A, 48B. The outer side surface of the arm portion 46 and the valve connecting portion 47 are complemented. Since the connecting wall portion 50 ..., it is possible to increase the rigidity of the joint portion of the valve connecting part 47 ... and the second arm portion 46 ....

  Moreover, the reinforcing wall portion 50 connects the outer surfaces of the boss portions 45 and the second arm portions 46 of the second rocker arms 26A and 26B, and the boss portion 45 and the second arm portion 46. Since the inner wall surfaces are also connected by the reinforcing wall portions 51..., The rigidity of the second rocker arms 26A, 26B can be increased, whereby the first and second intake valves V1, V2 are used as the profile of the valve cam 21. It can be opened and closed by following precisely.

  Further, the reinforcing wall portions 50, 51,... Are opposed to the roller support portions 38,... And the rollers 25 of the first rocker arm 23 at a position retracted from the sliding surfaces 48A, 48B on the opposite side to the roller shaft 24. Therefore, it is possible to prevent the vertical width of the second rocker arms 26A, 26B from increasing by providing the reinforcing wall portions 50, 51,.

  The bosses 45 of the pair of second rocker arms 26A, 26B, at least one of the roller support portion 38 of the first rocker arm 23 and the roller 25, in this first embodiment, a notch 52 to avoid interference with both. , 53..., Even if the sliding surfaces 48A, 48B are arranged close to the fixed support shaft 44 that supports the boss portions 45 so as to be swingable, the roller support portion of the first rocker arm 23 is provided. 38, and at least one of the rollers 25, in this embodiment, both can be prevented from interfering with the bosses 45, and the length of the second rocker arms 26A, 26B can be set short to reduce the size of the valve operating device. Can contribute.

  In addition, the notches 52... 53 are formed so as to expose a part of the outer peripheral surface of the fixed support shaft 44. Therefore, the notches 52... Between the fixed support shaft 44 and the boss 45. 53. Oil can be guided from 53... And lubrication between the second rocker arms 26A and 26B and the fixed support shaft 44 can be performed satisfactorily.

  Also, the oil guide surfaces 54... 55 connected to the notches 52... 53 are formed on the reinforcing wall portions 50. .., 55... Can guide the oil to the notches 52... 53, and the lubrication between the second rocker arms 26 A and 26 B and the fixed support shaft 44 can be performed more efficiently.

  Further, the sliding surfaces 48A and 48B of the second rocker arms 26A and 26B are formed with oil holding recesses 57A and 57B capable of holding oil. By storing the oil in the oil holding recesses 57A and 57B, the rollers By supplying oil between the shaft 24 and the sliding surfaces 48A and 48B, the frictional resistance between the roller shaft 24 and the sliding surfaces 48A and 48B can be reduced.

  Moreover, since the oil retaining recesses 57A and 57B are formed in a groove shape in a plane perpendicular to the axis of the roller shaft 24, the oil retaining recess 57A covers the entire sliding contact range of the roller shaft 24 with respect to the sliding surfaces 48A and 48B. , 57B can be formed easily.

  The bosses 45 of the second rocker arms 26A and 26B are provided with oil discharge ports 58 that communicate with an oil supply path 59 provided in the fixed support shaft 44 and discharge oil toward the oil holding recesses 57A and 57B. Therefore, oil can be reliably supplied to the oil holding recesses 57A and 57B.

  Furthermore, since the oil retaining recess 57B provided on the sliding surface 48B of the other second rocker arm 26B is formed so as to become shallower toward the second axis C2 side, that is, the fixed support shaft 44 side, the oil retaining recess 57B is formed. It is possible to suppress a decrease in rigidity of the second rocker arm 26B due to the formation.

  As another embodiment of the present invention, a pair of valve cams individually corresponding to the pair of intake valves V1 and V2 are provided on the camshaft 22, and a pair of divided rollers are provided to be in rolling contact with each valve cam. The first rocker arm may be supported via a roller shaft, and both roller shafts may be in sliding contact with the sliding surfaces 48A and 48B of the pair of second rocker arms 26A and 26B. In this way, the opening / closing operation characteristics of the operation characteristics of the pair of intake valves V1, V2 can be changed in a wider region including the opening / closing timing.

  10 is a plan view of a valve operating apparatus according to a second embodiment of the present invention, FIG. 11 is a cross-sectional view taken along the line 11-11 in FIG. 10, FIG. 12 is a cross-sectional view taken along the line 12-12 in FIG. 14 is a cross-sectional view taken along the line 14-14 of FIG. 10, and the portions corresponding to the first embodiment are only shown with the same reference numerals, and the detailed description thereof is as follows. Omitted.

  First, in FIGS. 10 to 12, this valve operating device includes a camshaft 22 provided with a valve operating cam 21 common to the first and second intake valves V 1, V 2, and a first axis parallel to the axis of the camshaft 22. A first rocker arm 23 that can swing around C1, a roller 25 that is supported by roller support portions 38, 38 provided on the first rocker arm 23 via a roller shaft 24 and that is in rolling contact with the valve cam 21; It has sliding surfaces 68 and 68 for sliding contact with the roller shaft 24, and is individually linked and connected to both intake valves V1 and V2 and is rotatable about a second axis C2 parallel to the first axis C1. A single second rocker arm 64, and in this embodiment, the first axis C1 is displaced in a plane perpendicular to the axis of the camshaft 22 in either of the first and second axes C1 and C2. It is a function.

  The first rocker arm 23 has the same shape as that of the first embodiment and is disposed between the holders 35, 35, and a pair of first arm portions 36 along a plane perpendicular to the axis of the camshaft 22. , 36 and a movable support shaft 37 that has a first axis C1 and connects the base ends of the first arm portions 36, 36, and is provided at the distal ends of the first arm portions 36, 36, respectively. Both end portions of the roller shaft 24 are supported between the circular roller support portions 38, 38. Further, both ends of the movable support shaft 37 projecting outward from both the first arm portions 36 and 36 are shortly interposed between a pair of webs 39 a and 39 a provided in the control shaft 39 and both the first arm portions 36 and 36. It penetrates through the cylindrical spacers 40 and 40 and is rotatably supported by the two webs 39a.

  The second rocker arm 64 is formed symmetrically with respect to a plane passing through the center of the roller 25 in the axial direction, and is disposed below the first rocker arm 23. The second rocker arm 64 is rotatable about a fixed support shaft 44 having a second axis C2. A cylindrical boss portion 65 to be supported, a pair of second arm portions 66 and 66 extending from the boss portion 65, and both second arm portions 66 to be linked and connected to both intake valves V1 and V2. A pair of valve connecting portions 67 and 67 provided at the tip of the roller shaft 24 are integrally formed, and a portion between the roller 25 of the roller shaft 24 and the roller support portion 38 is slid on the upper surfaces of the second arm portions 66. Sliding surfaces 68 and 68 that are in contact with each other are provided.

  The fixed support shaft 44 is fixedly supported by the holder 35... And the pair of second arm portions 66... Extends in a plane orthogonal to the second axis C 2 of the fixed support shaft 44. Are provided at both ends in the axial direction.

  The valve connecting portions 67 are connected to the distal ends of the second arm portions 66 so as to protrude outward from the distal ends of the second arm portions 66, that is, opposite to each other. Tappet screws 49 that are in contact with the upper ends of the stem portions 31 of the intake valves V1 and V2 are screwed into the valve connecting portions 67 so that the forward and backward positions can be adjusted.

  Reinforcing wall portions 69, 69 facing the roller support portions 38 of the first rocker arm 23 by connecting the outer surfaces of the valve connecting portions 67 and the second arm portions 66 to the second rocker arm 64. Is provided. Moreover, the reinforcing wall portions 69 are formed so as to face the roller support portions 38 at a position retracted from the sliding surface 68 of the second arm portion 66 on the side opposite to the roller shaft 24. .

  By the way, the first rocker arm 23 disposed above the second rocker arm 64 is formed so that at least the roller support portions 38 overlap with the second rocker arm 64 in a plan view, and this second embodiment. Then, a part of roller support part 38 ... with which the 1st rocker arm 23 is provided is formed so that it may overlap with the reinforcement wall part 69 ... by planar view.

  In FIG. 13, the second rocker arm 64 has an outer connecting portion 70 that integrally connects the distal ends of the second arm portions 66, and the base end portion of the second arm portions 66, that is, the end portion on the boss portion 65 side. And an inner connecting portion 71 for integrally connecting the two.

  The boss portion 65 of the second rocker arm 64 is provided with a notch 72 that avoids interference with the roller of the first rocker arm 23, and the notch 72 is formed on a part of the outer peripheral surface of the fixed support shaft 44. It is formed to be exposed. Moreover, the notch 72 is formed so as to be continuous with the upper surface of the inner connecting portion 71, and an oil reservoir 73 recessed downward to store oil is formed on the upper surface of the inner connecting portion 71. It is possible to apply oil to the surface of the roller 25 in accordance with the oscillation of the roller 25.

  In FIG. 14, the upper surfaces of the second arm portions 66 of the second rocker arm 64 are provided with sliding surfaces 68 having the same shape, and the intervals between these sliding surfaces 68 are first and second. It is set to be smaller than the interval between the two intake valves V1, V2.

  In addition, oil retaining recesses 74 and 74 that can retain oil are formed in the sliding surface 68. These oil retaining recesses 74 are grooves in a plane perpendicular to the axis of the roller shaft 24. It is formed in a shape.

  The boss portion 65 of the second rocker arm 64 is provided with a pair of oil discharge ports 75 that open toward the pair of oil holding recesses 74..., And these oil discharge ports 75. It communicates with an oil supply passage 59 provided inside through an annular recess 60... And a communication hole 61.

  Next, the operation of the second embodiment will be described. Since at least the roller support portions 38 of the first rocker arm 23 are arranged at a position overlapping the second rocker arm 64 in plan view, the first and second intake valves V1. , V2 and the second rocker arm 64 linked to and coupled to the second rocker arm 64, the amount of displacement of the first rocker arm 23 in the direction along the axis of the camshaft 22 is reduced, and the valve operating device in the direction along the axis of the camshaft 22 is reduced. Can be achieved.

  In addition, since the distance between the pair of sliding surfaces 68 of the single second rocker arm 64 is set smaller than the distance between the first and second intake valves V1, V2, the sliding that the second rocker arm 64 has. Regardless of the position of the first rocker arm 23 in the direction along the axis of the camshaft 22 with respect to the surface 68..., The second rocker arm 23 is narrower than the distance between the first and second intake valves V1, V2. By arranging the sliding surfaces 68 of the rocker arm 64, it is possible to reduce the size of the valve operating device in the direction along the axis of the camshaft 22.

  In addition, since the distance between the sliding surfaces 68 is smaller than the distance between the intake valves V1, V2, the pair of valve connecting portions 67, 67 in the second rocker arm 64 has the sliding surfaces 68, 68. The two arm portions 66, 66 have to be arranged so as to protrude outward from the tip, but the outer surface of the second arm portion 66 ... and the valve connecting portion 67 ... are connected by the reinforcing wall portion 69 ... The rigidity of the connecting portions of the connecting portions 67 and the second arm portions 66 can be increased.

  Further, since the reinforcing wall portions 69 are formed so as to face the roller holding portions 38 at a position retracted from the sliding surface 68 on the side opposite to the roller shaft 24, the reinforcing wall portions 69 are provided. By providing, it is possible to avoid the vertical width of the second rocker arm 64 from increasing.

  In addition, the second rocker arm 64 is provided with an outer connecting portion 70 that integrally connects the distal ends of the second arm portions 66... And an inner connecting portion 71 that integrally connects the proximal ends of the second arm portions 66. The rigidity of the second rocker arm 64 can be increased, whereby the intake valves V1 and V2 can be opened and closed by accurately following the porofil of the valve cam 21.

  Since the boss portion 65 of the second rocker arm 64 is provided with a notch portion 72 that avoids interference with the roller 25, the boss portion 65 of the second rocker arm 64 is close to the fixed support shaft 44 that supports the boss portion 65 so as to be swingable. Even if the sliding surfaces 68 are arranged, the roller 25 of the first rocker arm 23 can be prevented from interfering with the boss portion 65, and the length of the second rocker arm 64 is set to be short so that This can contribute to downsizing.

  Moreover, since the notch 72 is formed so as to expose a part of the outer peripheral surface of the fixed support shaft 44, oil can be guided from the notch 72 between the fixed support shaft 44 and the boss portion 65. Thus, the lubrication between the second rocker arm 64 and the fixed support shaft 44 can be performed satisfactorily.

  In addition, an oil storage portion 73 that is recessed downward to store oil is formed on the upper surface of the inner connecting portion 71 so that oil can be applied to the surface of the roller 25 in accordance with the swing of the second rocker arm 64. Therefore, the lubrication between the roller 25 and the valve cam 21 can be performed satisfactorily.

  Further, the sliding surfaces 68 of the second rocker arm 64 are formed with oil retaining recesses 74 capable of retaining oil, and the oil is stored in the oil retaining recesses 74 so that the roller shaft 24 and the sliding surface are slid. It is possible to reduce the frictional resistance between the roller shaft 24 and the sliding surfaces 68 by supplying oil between the surfaces 68.

  Moreover, since the oil retaining recesses 74 are formed in a groove shape in a plane perpendicular to the axis of the roller shaft 24, the oil retaining recesses 74 over the entire sliding contact range of the roller shaft 24 with the sliding surface 68 are provided. It can be easily formed.

  Also, the boss portion 65 of the second rocker arm 64 is provided with oil discharge ports 75 that lead to an oil supply passage 59 provided in the fixed support shaft 44 and discharge oil toward the oil holding recesses 74. Oil can be reliably supplied to the recesses 74.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various design changes can be made without departing from the present invention described in the claims. It is.

  For example, in the above embodiments, the intake valves V1 and V2 have been described as engine valves. However, the present invention can also be implemented in connection with an exhaust valve that is an engine valve.

It is a top view of the valve gear of 1st Example. It is a top view of the valve operating apparatus in the state which abbreviate | omitted the control shaft and the 1st rocker arm. FIG. 3 is a sectional view taken along line 3-3 in FIG. 1. FIG. 4 is a sectional view taken along line 4-4 of FIG. FIG. 5 is a sectional view taken along line 5-5 of FIG. FIG. 6 is a sectional view taken along line 6-6 of FIG. It is sectional drawing which shows the maximum lift state (a) and the minimum lift state (b) along the 7-7 line | wire of FIG. It is sectional drawing which shows the maximum lift state (a) and the minimum lift state (b) along the 8-8 line of FIG. It is a figure which shows the lift characteristic of both intake valves, making the 1st intake valve (a) and the 2nd intake valve (b). It is a top view of the valve gear of 2nd Example. It is the 11-11 line sectional view of FIG. 12 is a sectional view taken along line 12-12 of FIG. FIG. 13 is a sectional view taken along line 13-13 of FIG. 14 is a cross-sectional view taken along line 14-14 of FIG.

Explanation of symbols

21 ... Valve cam 22 ... Cam shaft 23 ... First rocker arm 24 ... Roller shaft 25 ... Rollers 26A, 26B, 64 ... Second rocker arm 38 ... Roller support 44 ... support shafts 45, 65 ... boss parts 46,66 ... arm parts 48A, 48B, 68 ... sliding surfaces 52, 53, 72 ... notches 54,55 ... oil Guide surface C1... First axis C2... Second axis V1, V2.

Claims (4)

  A camshaft (22) provided with a valve cam (21), a first rocker arm (23) swingable about a first axis (C1) parallel to the axis of the camshaft (22), and a first rocker arm A roller (25) supported by a roller support (38) provided on (23) via a roller shaft (24) and in rolling contact with the valve cam (21); a first axis (C1); Cylindrical bosses (45, 65) that are rotatably supported by a support shaft (44) having a parallel second axis (C2), and sliding surfaces (48A, 48A, slidably contacting the roller shaft (24)) 48B, 68) and a second rocker arm (26A, 26A, 26A, 26A) having an arm portion (46, 66) extending from the boss portion (45, 65) and being linked to and coupled to the engine valve (V1, V2). 26B, 64), and the first and In the valve gear for an engine in which any one of the second axes (C1, C2) is displaced within a plane orthogonal to the axis of the camshaft (22), the second rocker arm (26A, 26B, 64) The boss portions (45, 65) are provided with notches (52, 53, 72) for avoiding interference with at least one of the roller support portion (38) and the roller (25) of the first rocker arm (23). A valve operating apparatus for an engine.   The engine operation according to claim 1, wherein the boss (45) is provided with a notch (52, 53) for avoiding interference with the roller (25) and the roller support (38). Valve device.   The valve gear for an engine according to claim 1, wherein the notch (52, 53, 72) is formed so as to expose a part of the outer peripheral surface of the support shaft (44).   The engine operation according to claim 3, wherein an oil guide surface (54, 55) connected to the notch (52, 53) is formed on the second rocker arm (26A, 26B) so as to face upward. Valve device.

Images