JP4502917B2 - Oil supply structure in valve mechanism of internal combustion engine - Google Patents

Description

  The present invention relates to a drive rocker arm that opens and closes an intake valve or an exhaust valve of a multi-cylinder internal combustion engine, a free rocker arm that can be connected to and disconnected from the drive rocker arm by a switching mechanism, a drive rocker arm, and a free rocker arm A rocker shaft that pivotally supports the rocker shaft, a rocker shaft holder that extends in the cylinder arrangement direction to support the rocker shaft, and a lost motion spring that biases the free rocker arm in a direction to contact the valve cam. The present invention relates to a valve operating mechanism of an internal combustion engine, and more particularly to an oil supply structure thereof.

  In an internal combustion engine having a variable valve timing / valve lift mechanism capable of changing the valve timing and valve lift, a portion where the free rocker arm of the variable valve timing / valve lift mechanism abuts on the lost motion spring (hereinafter referred to as a spring abutting portion). In order to lubricate the rocker shaft holder, an oil sump groove formed on the upper surface of the rocker shaft holder and extending in the cylinder arrangement direction and a lost motion spring accommodating portion of each cylinder are connected by a lubricating oil passage. 1 is known.

  In general, a portion where the stem end of the intake valve located on the inner side of the bank of the V-type internal combustion engine comes into contact with an adjustment screw of the rocker arm (hereinafter referred to as a valve contact portion) Lubrication is difficult. Therefore, conventionally, in a valve operating mechanism comprising a drive rocker arm that opens and closes an intake valve or an exhaust valve of an internal combustion engine and a free rocker arm that can be connected to and disconnected from the drive rocker arm by a switching mechanism, The valve contact portion and the spring contact portion are disposed between the valve contact portion of the rocker arm and the rocker shaft, and the valve contact portion and the spring contact portion are lubricated with oil leaking from the switching mechanism.

For the exhaust valve located on the outer side of the bank, the lost motion spring is supported by the rocker shaft holder, and oil is supplied to the lost motion spring from the oil distribution passage provided on the upper surface of the rocker shaft holder. Both the spring contact portion and the valve contact portion are lubricated by introducing the oil lubricated with oil from the upper surface of the rocker arm to the valve contact portion.
JP 2005-2971 A

  By the way, conventionally, since the switching mechanism is arranged between the valve contact portion of the rocker arm and the rocker shaft, a tensile stress is generated around the switching pin hole of the switching mechanism at the time of valve lift, and the deformation amount of the rocker arm is reduced. There is a problem that this increases, which hinders high rotation of the valve mechanism.

  In order to solve this, the position of the switching mechanism is changed, and an oil supply passage for supplying oil from the oil distribution passage on the upper surface of the rocker shaft holder to the lost motion spring is provided in the same manner as the conventional exhaust valve side, It is conceivable to guide the lubricating oil to the valve contact portion through the contact portion. However, in this case, if the amount of oil supplied from the oil distribution passage to the oil supply passage decreases when the oil pressure is low, such as during idling, a sufficient amount of oil may not be supplied to the valve contact portion. There is.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to stably lubricate both a spring contact portion and a valve contact portion of a rocker arm.

  In order to achieve the above object, according to the first aspect of the present invention, a drive rocker arm that opens and closes an intake valve or an exhaust valve of a multi-cylinder internal combustion engine and a drive rocker arm connected and connected by a switching mechanism. A free rocker arm that can be released, a rocker shaft that pivotally supports the drive rocker arm and the free rocker arm, a rocker shaft holder that extends in the cylinder arrangement direction to support the rocker shaft, and operates the free rocker arm In a valve operating mechanism of an internal combustion engine provided with a lost motion spring that is biased in a direction in contact with a cam, the drive rocker arm has a valve abutting portion that contacts an intake valve or an exhaust valve, and the free rocker arm is a valve operating valve. A cam contact part that contacts the cam and a spring contact that contacts the lost motion spring The cam contact portion, the switching mechanism, and the spring contact portion are on one side with respect to a plane that passes through the rocker shaft axis and is orthogonal to a straight line that connects the rocker shaft axis and the valve contact portion. In addition, the valve contact part is located on the other side, the lost motion spring is attached to the rocker shaft holder above the free rocker arm, and an oil reservoir is provided on the upper surface of the free rocker arm to collect oil leaking from the switching mechanism. An oil supply structure for a valve mechanism of an internal combustion engine is proposed in which the spring contact portion is lubricated and the valve contact portion is lubricated with oil supplied from the upper surface of the rocker shaft holder.

  The adjusting screws 28 and 31 of the embodiment correspond to the valve contact portion of the present invention, and the rollers 32 and 34 of the embodiment correspond to the cam contact portion of the present invention.

  According to the configuration of the first aspect, the valve contact portion in which the drive rocker arm contacts the intake valve or the exhaust valve, the cam contact portion in which the free rocker arm contacts the valve operating cam, and the free rocker arm is the lost motion spring. And a switching mechanism for connecting and releasing the drive rocker arm and the free rocker arm are orthogonal to a straight line passing through the rocker shaft axis and connecting the rocker shaft axis and the valve contact portion. The cam contact part, the switching mechanism, and the spring contact part are arranged on one side and the valve contact part is arranged on the other side with respect to the flat surface to be input from the valve cam or lost motion spring. Control the lift of the rocker arm in the vicinity of the switching mechanism caused by the generated load to control the valve lift with high accuracy and speed up the valve mechanism It is possible to achieve. An oil reservoir is provided on the upper surface of the free rocker arm to collect oil leaking from the switching mechanism. The spring abutment is lubricated with the oil in the oil reservoir, and the valve abuts with the oil supplied from the upper surface of the rocker shaft holder. Since the portion is separately lubricated, both the spring contact portion and the valve contact portion can be stably lubricated even when the hydraulic pressure is low, such as during idling. In addition, by attaching the lost motion spring to the rocker shaft holder above the free rocker arm and assembling it, the spring contact of the free rocker arm is reduced while reducing the number of assembly steps compared to attaching the lost motion spring to the cylinder head. The part can be lubricated.

  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.

  1 to 12 show an embodiment of the present invention. FIG. 1 is a top view of a cylinder head of one bank of a V-type 6-cylinder internal combustion engine (a view taken along the line 1-1 in FIG. 2). 2 is a sectional view taken along line 2-2 in FIG. 1, FIG. 3 is a sectional view taken along line 3-3 in FIG. 2, FIG. 4 is a sectional view taken along line 4-4 in FIG. 6 is a sectional view taken along line 6-6 in FIG. 3, FIG. 7 is a sectional view taken along line 7-7 in FIG. 3, FIG. 8 is a plan view of a rocker shaft holder, and FIG. 10 is a sectional view taken along line 10-10 in FIG. 8, FIG. 11 is a sectional view taken along line 11-11 in FIG. 8, and FIG. 12 is a sectional view taken along line 12-12 in FIG.

  As shown in FIGS. 1 to 7, an intake port 12 and an exhaust port 13 connected to the combustion chamber 11 are formed in the cylinder head 10 of one bank of the V-type 6-cylinder internal combustion engine, and the intake valve hole 14 serves as a valve guide. 15 is opened and closed by the umbrella portion 16b of the intake valve 16 guided slidably by the stem 16a, and the exhaust valve hole 17 is formed by the umbrella portion 19b of the exhaust valve 19 guided slidably by the valve guide 18 and the stem 19a. Opened and closed. The intake valve 16 and the exhaust valve 19 are urged in the valve closing direction by valve springs 61 and 62, respectively, and are controlled to open and close by a valve mechanism 21 driven by a camshaft 20 rotatably supported by the cylinder head 10. The

  A rocker shaft holder 22 is fastened to the cylinder head 10 by a plurality of bolts 23, and an intake side rocker shaft 24 and an exhaust side rocker shaft 25 are supported by the rocker shaft holder 22 along the cylinder arrangement direction.

  An intake-side drive rocker arm 26 and an intake-side free rocker arm 27 are swingably supported on the intake-side rocker shaft 24, and the intake-side drive rocker arm 26 abuts an adjustment screw 28 on the upper end of the stem 16 a of the intake valve 16. As a result, the intake valve 16 is always linked and connected. One intake side drive rocker arm 26 and one intake side free rocker arm 27 are provided for each of the pair of intake valves 16, 16, and the intake side drive rocker arm 26 drives the pair of intake valves 16, 16. Therefore, the tip is formed to be bifurcated.

  An exhaust-side drive rocker arm 29 and an exhaust-side free rocker arm 30 are swingably supported on the exhaust-side rocker shaft 25. The exhaust-side drive rocker arm 29 applies an adjustment screw 31 to the upper end of the stem 19a of the exhaust valve 19. By being in contact, the exhaust valve 19 is always linked and connected. One exhaust side drive rocker arm 29 and one exhaust side free rocker arm 30 are provided for each of the pair of exhaust valves 19, 19.

  The camshaft 20 includes an intake side valve cam 33 (see FIG. 5) that makes a roller 32 that is pivotally supported by the intake side free rocker arm 27 in rolling contact, and a roller that is pivotally supported by the exhaust side free rocker arms 30 and 30. A pair of exhaust side valve cams 35 and 35 (see FIG. 7) that are in rolling contact with 34 and 34, respectively, and a raised portion 37 (see FIG. 4) that is in sliding contact with a roller 36 provided on the intake side drive rocker arm 26; A pair of raised portions 39, 39 (see FIG. 6) are provided which are in sliding contact with the rollers 38, 38 provided on the exhaust side drive rocker arms 29, 29.

  The intake side valve cam 33 is formed to have a cam profile for opening and closing the intake valve 16, and the exhaust side valve cam 35 is formed to have a cam profile for opening and closing the exhaust valve 19. The portions 37 and 39 are formed so that the intake valve 16 and the exhaust valve 19 are substantially closed. Therefore, the intake valve 16 opens and closes when the intake side drive rocker arm 26 is connected to the intake side free rocker arm 27, but the connection of the intake side drive rocker arm 26 to the intake side free rocker arm 27 is released. In some cases, the valve is substantially closed. The exhaust valve 19 opens and closes when the exhaust side drive rocker arm 29 is connected to the exhaust side free rocker arm 30, but the connection of the exhaust side drive rocker arm 29 to the exhaust side free rocker arm 30 is released. In some cases, the valve is substantially closed.

  The intake-side drive rocker arm 26 and the intake-side free rocker arm 27 are provided with an intake-side switching mechanism 40 that switches connection and release of the intake-side drive rocker arm 26 to and from the intake-side free rocker arm 27 by hydraulic pressure.

  The intake side switching mechanism 40 has one end facing the first hydraulic chamber 41 formed in the intake side drive rocker arm 26 and the other end facing the second hydraulic chamber 42 formed in the intake side free rocker arm 27. And a connection pin 43 slidably fitted to the intake-side drive rocker arm 26 and the intake-side free rocker arm 27, and an intake-side free rocker arm 27 and the connection pin 43 housed in the second hydraulic chamber 42. And a return spring 44 provided therebetween.

  In the intake side switching mechanism 40, when hydraulic pressure is applied to the first hydraulic chamber 41, the connecting pin 43 moves to the second hydraulic chamber 42 side, and the intake side free rocker arm 27 and the intake side drive rocker arm 26 are connected. Is released. Conversely, when the hydraulic pressure acting on the first hydraulic chamber 41 is removed, the connecting pin 43 moves to the first hydraulic chamber 41 side by the elastic force of the return spring 44, and the intake-side free rocker arm 27 and the intake-side drive rocker arm 26. Are concatenated. In this way, the intake-side switching mechanism 40 switches the connection and release of the intake-side free rocker arm 27 to the intake-side drive rocker arm 26 by supplying the hydraulic pressure to the first hydraulic chamber 41, thereby operating the intake valve 16. Can be changed.

  A split member 45 that divides the intake side rocker shaft into two parts is fitted in the intake side rocker shaft 24, and the first hydraulic chamber 41 is provided in the intake side rocker shaft 24 by the split member 45. A first hydraulic oil passage 46 communicating with the second hydraulic fluid passage 47 and a second hydraulic oil passage 47 communicating with the second hydraulic chamber 42 are formed independently of each other.

  Further, the exhaust-side drive rocker arm 29 and the exhaust-side free rocker arm 30 that are adjacently arranged in pairs on the exhaust valve 19 side are connected to and disconnected from the exhaust-side free rocker arm 30. An exhaust side switching mechanism 48 that switches hydraulically is provided.

  The exhaust side switching mechanism 48 has one end facing the first hydraulic chamber 49 formed in the exhaust side drive rocker arm 29 and the other end of the second hydraulic chamber 50 formed in the exhaust side free rocker arm 30. A connection pin 51 slidably fitted to the exhaust side drive rocker arm 29 and the exhaust side free rocker arm 30 and a space between the exhaust side drive rocker arm 29 and the connection pin 51 accommodated in the first hydraulic chamber 49. And a return spring 52.

  In the exhaust side switching mechanism 48, when the hydraulic pressure acting on the second hydraulic chamber 50 is released, the connecting pin 51 moves to the second hydraulic chamber 50 side by the elastic force of the return spring 52, and the exhaust side free rocker arm 30 and The exhaust side drive rocker arm 29 is connected. Conversely, when hydraulic pressure is applied to the second hydraulic chamber 50, the connecting pin 51 moves to the first hydraulic chamber 49 side against the elastic force of the return spring 52, and the exhaust-side free rocker arm 30 and the exhaust-side drive rocker. The connection of the arm 29 is released. In this way, the exhaust-side switching mechanism 48 switches the connection and release of the exhaust-side free rocker arm 30 to the exhaust-side drive rocker arm 29 by supplying the hydraulic pressure to the second hydraulic chamber 50 to operate the exhaust valve 19. Can be changed.

  A split member 53 that divides the exhaust side rocker shaft 28 into two parts is fitted in the exhaust side rocker shaft 25, and the first hydraulic chamber is placed in the exhaust side rocker shaft 25 by the split member 53. A first hydraulic oil passage 54 leading to 49 and a second hydraulic oil passage 55 leading to the second hydraulic chamber 50 are formed independently of each other.

  The intake side for biasing the intake-side free rocker arm 27 to the intake-side valve cam 33 of the camshaft 20 in a state where the intake-side switching mechanism 40 releases the connection of the intake-side free rocker arm 27 to the intake-side drive rocker arm 26. A lost motion spring 56 is provided between the rocker shaft holder 22 and the intake side free rocker arm 27. Further, the exhaust side switching mechanism 48 urges the exhaust side free rocker arm 30 to the exhaust side valve cam 35 of the camshaft 20 in a state where the connection of the exhaust side free rocker arm 30 to the exhaust side drive rocker arm 29 is released. A side lost motion spring 57 is provided between the rocker shaft holder 22 and the exhaust side free rocker arm 30.

  On the base end side of the intake-side free rocker arm 27, a roller 32 that contacts the intake-side valve cam 33 and a spring contact portion 27b that contacts the intake-side lost motion spring 56 are provided. An adjustment screw 28 that comes into contact with the upper end of the stem 16 a of the intake valve 16 is provided on the distal end side, and the intake side switching mechanism 40 is located closer to the intake side drive rocker arm 26 and the intake side free rocker arm 27 than the intake side rocker shaft 24. It is arranged on the base end side. Similarly, on the base end side of the exhaust-side free rocker arm 30, a roller 34 that contacts the exhaust-side valve cam 35 and a spring contact portion 30b that contacts the exhaust-side lost motion spring 57 are provided, and an exhaust-side drive rocker An adjustment screw 31 that abuts the upper end of the stem 19a of the exhaust valve 19 is provided on the distal end side of the arm 29, and the exhaust side switching mechanism 48 is located on the exhaust side drive rocker arm 29 and the exhaust side free rocker rather than the exhaust side rocker shaft 25. It is arranged on the proximal end side of the arm 30.

  That is, as shown in FIGS. 4 and 5, the intake side valve cam is in a plane Pi that passes through the axis of the intake side rocker shaft 24 and is orthogonal to a straight line connecting the axis of the intake side rocker shaft 24 and the adjusting screw 28. The roller 32 abutting on 33, the intake side switching mechanism 40, and the spring abutting portion 27b are arranged on the cylinder axis side, and the adjusting screw 28 is arranged on the anti-cylinder axis side. Further, as shown in FIGS. 6 and 7, the exhaust side valve cam 35 is arranged with respect to a plane Po that passes through the exhaust side rocker shaft 25 through the axis and is orthogonal to a straight line connecting the axis line of the exhaust side rocker shaft 25 and the adjusting screw 31. The roller 34, the exhaust side switching mechanism 48, and the spring contact portion 30b that are in contact with each other are disposed on the cylinder axis side, and the adjustment screw 31 is disposed on the anti-cylinder axis side.

  As shown in FIGS. 8 to 12, the rocker shaft holder 22 is configured by a rectangular parallelepiped block with a lot of lightening, and the bolts penetrating 11 bolt holes 22 a formed on the outer periphery thereof. 23 (see FIG. 1), the cylinder head 10 is fixed. The rocker shaft holder 22 includes four intake-side rocker shaft support portions 22b on the intake-side side surface, and the intake-side rocker shaft 24 passes through support holes 22c formed in the intake-side rocker shaft support portions 22b. Supported. The rocker shaft holder 22 includes seven exhaust side rocker shaft support portions 22d on the exhaust side surface, and the exhaust side rocker shaft 25 is inserted into support holes 22e formed in the exhaust side rocker shaft support portions 22d. Penetrated and supported.

  As apparent from FIG. 8, a groove-like oil distribution passage 22f is formed on the intake side upper surface of the rocker shaft holder 22 along the cylinder arrangement direction, and is separated from the oil distribution passage 22f in the cylinder arrangement direction. Three groove-like oil supply passages 22j, 22k, 22m corresponding to the three intake side drive rocker arms 26... Branch in a right angle direction from the three branch portions 22g, 22h, 22i. Each oil supply passage 22j, 22k, 22m has a downwardly inclined end opened, and an oil receiving groove 26a formed on the upper surface of the intake side drive rocker arm 26 is located below the open end (FIG. 4). reference). The portion of the intake side drive rocker arm 26 that is closer to the adjustment screw 28 than the intake side rocker shaft 25 is bifurcated to correspond to the two intake valves 16, 16, and the end of the oil receiving groove 26 a is intake air. It ends before the side drive rocker arm 26 branches (see FIG. 3).

  Of the three oil supply passages 22j, 22k, 22m, from the oil supply passage 22j close to one end (upstream end) side of the oil distribution passage 22f toward the oil supply passage 22m close to the other end (downstream end) side The width and depth of the entrance are gradually increasing. That is, the upstream oil supply passage 22j has the smallest inlet cross-sectional area, the downstream oil supply passage 22m has the largest inlet cross-sectional area, and the intermediate oil supply passage 22k has the inlet passage cut-off. The area is an intermediate size (see FIG. 9).

  The rocker shaft holder 22 is provided with three spring accommodating portions 22n for accommodating intake-side lost motion springs 56 for urging the intake-side free rocker arms 27, and one of the spring accommodating portions 22n. The portion protrudes from the bottom surface of the oil distribution passage 22f as three raised portions 58 (see FIGS. 8 and 12), and also serves as a side wall of the oil supply passages 22j, 22k, and 22m. Each of the raised portions 58 is located adjacent to the downstream side of the branch portions 22g, 22h, and 22i of the oil distribution passage 22f, and the flow passage cross-sectional area of the oil distribution passage 22f is narrowed at that portion. The rocker shaft holder 22 is provided with six spring accommodating portions 22o for accommodating intake-side lost motion springs 57 for urging the exhaust-side free rocker arms 30. As shown in FIG. 1, first hydraulic fluid passages 46 and 54 and second hydraulic fluid passages 47 formed in the intake side and exhaust side rocker shafts 25 and 26 on one end side along the cylinder arrangement direction of the cylinder head 10. , 55 is provided with a hydraulic control valve 59 for controlling the hydraulic pressure of the hydraulic oil supplied to the hydraulic oil. A drain oil passage 60 for discharging drain oil when the hydraulic control valve 59 is switched faces above the upstream end of the oil distribution passage 22f.

  As is apparent from FIG. 5, an oil reservoir 27a is formed on the upper surface of the intake-side free rocker arm 27, and a spring contact portion 27b that contacts the intake-side lost motion spring 56 in the vicinity of the oil reservoir 27a. Is provided. Similarly, as apparent from FIG. 7, an oil reservoir 30a is formed on the upper surface of the exhaust / exhaust-side free rocker arm 30, and a spring that abuts the exhaust-side lost motion spring 57 in the vicinity of the oil reservoir 30a. A contact portion 30b is provided.

  Next, the operation of this embodiment will be described.

  Excess drain oil from the hydraulic control valve 59 that supplies hydraulic pressure to the intake-side and exhaust-side switching mechanisms 40, 48 is supplied from the drain oil passage 60 to one end of the oil distribution passage 22 f on the upper surface of the rocker shaft holder 22. Then, it flows toward the other end, and branches into three oil supply passages 22j, 22k, and 22m at three branch portions 22g, 22h, and 22i in the middle. The oil flowing through the oil supply passages 22j, 22k, and 22m falls into the oil receiving grooves 26a on the upper surface of the three intake side drive rocker arms 26, and then branches into two branches to provide two adjustment screws 28 and 28, respectively. And the contact portion between the adjustment screws 28 and 28 and the upper ends of the stems 16a and 16a of the intake valves 16 and 16 is lubricated.

  As the oil branches from the oil distribution passage 22f to the oil supply passages 22j, 22k, and 22m at the branch portions 22g, 22h, and 22i, the flow rate of the oil flowing through the oil distribution passage 22f gradually increases from one end side to the other end side. Decrease. Therefore, if the ratio of the amount of oil branched from the oil distribution passage 22f to the oil supply passages 22j, 22k, 22m in each branch portion 22g, 22h, 22i is constant, the oil from the branch portion 22g on one end side of the oil distribution passage 22f The amount of oil branched to the supply passage 22j increases, and the amount of oil branched to the oil supply passage 22m from the branch portion 22i on the other end side of the oil distribution passage 22f decreases.

  However, according to the present embodiment, the flow passage cross-sectional area of the inlets of the three oil supply passages 22j, 22k, and 22m is configured to gradually increase from the one near the one end of the oil distribution passage 22f to the far one ( 9), the ratio of the amount of oil to be branched is reduced at the branch portion 22g on one end side where the oil flow rate is large, and the ratio of the oil amount to be branched is increased at the branch portion 22i on the other end side where the flow rate of oil is small. Thus, the oil can be evenly distributed to all the oil supply passages 22j, 22k, and 22m. Accordingly, even when the amount of oil supplied to the oil distribution passage 22f is small, all the intake-side drive rocker arms 26 can be reliably lubricated.

  Further, the intake side spring accommodating portions 22n formed in the rocker shaft holder 22 narrow the oil distribution passage 22f on the downstream side of the respective branch portions 22g, 22h, 22i, so that the oil flowing through the oil distribution passage 22f is branched. The oil can stay in the portions 22g, 22h, and 22i, and the oil can effectively flow into the oil supply passages 22j, 22k, and 22m from the oil distribution passage 22f. In addition, since the spring accommodating portions 22n can be brought closer to the cylinder axis by the amount of the narrow oil distribution passage 22f, the rocker shaft holder 22 can be reduced in size in the width direction.

  A roller 32 that contacts the intake side valve cam 33, an intake side switching mechanism 40, and a spring contact portion 27b are disposed on the cylinder axis side with respect to a plane Pi that passes through the intake side rocker shaft 24 and is parallel to the cylinder axis. Therefore, the deflection of the intake-side drive rocker arm 26 generated in the vicinity of the intake-side switching mechanism 40 due to the load input from the intake-side valve cam 33 and the intake-side lost motion spring 56 is suppressed to a small level, and the valve lift is accurately performed. The speed of the valve mechanism 21 can be increased while controlling.

  Similarly, with respect to a plane Po that passes through the exhaust side rocker shaft 25 and is parallel to the cylinder axis, the roller 34 that contacts the exhaust side valve cam 35, the exhaust side switching mechanism 48, and the spring contact portion 30b are located on the cylinder axis side. Therefore, the deflection of the exhaust-side drive rocker arm 29 generated in the vicinity of the exhaust-side switching mechanism 48 due to the load input from the exhaust-side valve cam 35 and the exhaust-side lost motion spring 57 is suppressed, and the valve lift is reduced. It is possible to control the valve mechanism 21 with high accuracy and to increase the speed of the valve mechanism 21.

  The oil leaked from the intake side switching mechanism 40 passes through the mating surface of the intake side drive rocker arm 26 and the intake side free rocker arm 27, and an oil reservoir 27a provided on the upper surface of the intake side free rocker arm 27 (see FIG. 5). And the spring contact portion 27b of the intake-side free rocker arm 27 located in the vicinity thereof is lubricated. Similarly, oil leaking from the exhaust side switching mechanism 48 passes through the mating surface of the exhaust side drive rocker arm 29 and the exhaust side free rocker arm 30 and is provided with an oil reservoir 30a provided on the upper surface of the exhaust side free rocker arm 30 (FIG. 7) and lubricates the spring contact portion 30b of the exhaust side free rocker arm 30 located in the vicinity thereof.

  In this way, the oil contact portions 29b, 30b are lubricated by the oil reservoir portions 27a, 30a of the intake side free rocker arm 27 and the exhaust side free rocker arm 30, and separately from this, the oil distribution passage 22f and the oil supply passage 22n, Since the adjustment screws 28 and 28 of the intake side drive rocker arm 26 are lubricated by the oil supplied from 22o and 22p, both the spring abutting portions 27b and 30b and the adjustment screws 28 and 31 are used even when the hydraulic pressure is low during idling or the like. Can be stably lubricated.

  Further, the intake-side and exhaust-side lost motion springs 56, 57 are attached to the rocker shaft holder 22 above the intake-side and exhaust-side free rocker arms 27, 30 to form an assembly. , 57 can be effectively lubricated with respect to the spring contact portions 27b, 30b of the intake-side and exhaust-side free rocker arms 27, 30 while reducing the number of assembling steps as compared with the case where they are attached to the cylinder head 10.

  Although the embodiments of the present invention have been described above, various design changes can be made without departing from the scope of the present invention.

  For example, although the V-type 6-cylinder internal combustion engine is illustrated in the embodiment, the present invention can be applied to all types of internal combustion engines having a cylinder row.

Top view of a cylinder head of one bank of a V-type 6-cylinder internal combustion engine (a view taken along line 1-1 in FIG. 2) 2-2 sectional view of FIG. 3-3 sectional view of FIG. Sectional view taken along line 4-4 in FIG. Sectional view along line 5-5 in FIG. 6-6 sectional view of FIG. Sectional view along line 7-7 in FIG. Top view of rocker shaft holder 9 direction arrow view of FIG. Sectional view taken along line 10-10 in FIG. Sectional view taken along line 11-11 in FIG. 12-12 sectional view of FIG.

Explanation of symbols

16 Intake valve 19 Exhaust valve 22 Rocker shaft holder 24 Intake side rocker shaft (rocker shaft)
25 Exhaust-side rocker shaft (rocker shaft)
26 Intake side drive rocker arm (drive rocker arm)
27 Intake side free rocker arm (free rocker arm)
27a Oil reservoir portion 27b Spring contact portion 28 Adjust screw (valve contact portion)
29 Exhaust side drive rocker arm (drive rocker arm)
30 Exhaust-side free rocker arm (free rocker arm)
30a Oil reservoir 30b Spring contact part 31 Adjust screw (valve contact part)
32 Roller (cam contact part)
33 Inlet side valve cam (valve cam)
34 Roller (cam contact part)
35 Exhaust valve cam (valve cam)
40 Intake side switching mechanism (switching mechanism)
48 Exhaust side switching mechanism (switching mechanism)
56 Lost motion spring 57 Lost motion spring Pi Passing through the rocker shaft axis and passing through the plane Po rocker shaft axis perpendicular to the straight line connecting the rocker shaft axis and the valve contact portion The rocker shaft axis and the valve contact portion A plane perpendicular to the connecting line

Claims (1)

A drive rocker arm (26, 29) for opening and closing an intake valve (16) or an exhaust valve (19) of a multi-cylinder internal combustion engine;
Free rocker arms (27, 30) that can be connected to and disconnected from the drive rocker arms (26, 29) by a switching mechanism (40, 48);
A rocker shaft (24, 25) for pivotally supporting the drive rocker arm (26, 29) and the free rocker arm (27, 30);
A rocker shaft holder (22) extending in the cylinder arrangement direction and supporting the rocker shaft;
A lost motion spring (56, 57) that urges the free rocker arm (27, 30) in a direction to contact the valve cam (33, 35);
In a valve operating mechanism of an internal combustion engine provided with
The drive rocker arm (26, 29) includes a valve contact portion (28, 31) that contacts the intake valve (16) or the exhaust valve (19), and the free rocker arm (27, 30) is a valve cam (33). , 35) and a cam contact portion (32, 34) that contacts the lost motion spring (56, 57).
A cam contact portion (32, 34) and a switching mechanism (Pi, Po) with respect to a plane (Pi, Po) passing through the rocker shaft axis and orthogonal to a straight line connecting the rocker shaft axis and the valve contact portion (28, 31). 40, 48) and the spring contact portion (27b, 30b) are located on one side, and the valve contact portion (28, 31) is located on the other side,
The lost motion spring (56, 57) is attached to the rocker shaft holder (22) above the free rocker arm (27, 30),
Oil reservoirs (27a, 30a) for accumulating oil leaking from the switching mechanism (40, 48) are provided on the upper surface of the free rocker arms (27, 30) to lubricate the spring contact parts (27b, 30b), and the rocker shaft An oil supply structure in a valve mechanism of an internal combustion engine, wherein the valve abutting portion (28, 31) is lubricated with oil supplied from the upper surface of the holder (22).

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