JP2009074508A - Lubricating structure of valve gear - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable stable and reliable lubrication irrespective of operating conditions, and in particular, lubrication of two parts simultaneously, i.e. the abutting part of a rocker arm with a member on the driving side and an abutting part with a member on the valve side. <P>SOLUTION: There are provided a slipper surface oil supplying hole 42 extending approximately in the radial direction from inside a base 35 of the rocker arm 6 and supplying a lubricating oil to the slipper surface 33 abutting to a roller shaft as a member on the driving side, and a tip part oil supplying hole 43 branching at a point on the way of the hole 42 and supplying the lubricating oil to the tip part abutting to the stem end of a valve. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a valve operating apparatus provided with a rocker arm that abuts a valve-side member that performs intake or exhaust and a drive-side member in an internal combustion engine and opens and closes the valve according to the operation of the drive-side member. It relates to a lubricating structure.

  An internal combustion engine is provided with a valve operating device that opens and closes a valve that performs intake and exhaust, and this valve operating device is provided with a rocker arm between a valve and a cam that causes the valve to open and close. A configuration in which the rocker arm swings in response to the rotation of the cam to open and close the valve is often used.

In this type of valve operating device, it is desirable to supply lubricating oil to the portion where the rocker arm and the cam abut in order to ensure the wear resistance of the cam. Conventionally, the valve operating device is accommodated as this lubricating method. An oil jet system is widely used in which a jet nozzle is placed at an appropriate position in the valve train, and lubricating oil is ejected from the jet nozzle to perform lubrication. A configuration provided with a lubricating oil receiving structure for collecting splashed lubricating oil is also employed. A technique is also known in which a lubricating oil supply hole is provided in a rocker arm to lubricate a contact portion with a cam (see Patent Document 1).
JP-A-5-312014

  However, the oil jet method has a problem in that stable lubrication is not performed because the supply state of the lubricating oil changes due to a change in hydraulic pressure in accordance with the operation state. On the other hand, piping for forcibly supplying lubricating oil to parts where there is a concern about lack of lubrication is also installed, but in this case, piping for lubricating oil supply is separately required. As a result, the number of parts increases and the design freedom in the layout is reduced.

  In addition, the technique of providing the lubricating oil supply hole in the rocker arm described above relates to the lubrication of the contact portion with the stem end of the valve, although the disadvantages such as an increase in the number of parts and a decrease in the design freedom in the layout are eliminated. If there is no consideration and insufficient lubrication occurs in this part, problems such as seizure may occur, and some countermeasure is desired.

  In particular, in order to improve output and fuel consumption, reduce harmful exhaust gas components, etc., when a valve opening characteristic variable mechanism that changes the lift amount of the valve according to the operating state of the internal combustion engine is provided in the valve operating device, Since the members constituting the variable valve opening characteristic mechanism are disposed in the vicinity of the rocker arm, these members reduce the gap around the rocker arm and hide the contact portion with the stem end of the valve. There is concern about lack of lubrication.

  The present invention has been devised to solve such problems of the prior art, and its main purpose is that stable and reliable lubrication is possible regardless of operating conditions. Another object of the present invention is to provide a lubrication structure for a valve operating apparatus that is configured to allow lubrication of a contact portion with a member on the valve side simultaneously with a contact portion with the member.

  In order to solve such a problem, according to the present invention, as shown in claim 1, in an internal combustion engine, a valve (2) side member (stem end 37) and a drive side member (roller) that perform intake or exhaust. In the lubrication structure of the valve operating apparatus provided with the rocker arm (6) that contacts the shaft 32) and opens and closes the valve according to the operation of the member on the driving side, it is substantially from the inside of the base (35) in the rocker arm. A drive-side oil supply passage (slipper surface oil supply hole 42) that extends in the radial direction and supplies lubricating oil to a contact portion (slipper surface 33) with the drive-side member, and branches from the middle of the drive-side oil supply passage. In addition, a driven-side oil supply passage (tip portion oil supply hole 43) for supplying lubricating oil to a contact portion (tip portion 38) with the valve side member is provided.

  According to this, since the lubricating oil is supplied to the contact portion with the drive side member and the contact portion with the valve side member, which are lubrication target parts, by the drive side oil supply passage and the driven side oil supply passage, Stable and reliable lubrication is possible regardless of conditions. Since the contact portion with the valve side member and the contact portion with the drive side member are lubricated, the wear resistance of the drive side member is improved, and the valve side member is seized. Problems can be prevented. In addition, since the drive-side oil supply passage and the driven-side oil supply passage are partially shared, the number of processing steps can be reduced.

  In this case, in the rocker arm, the contact portion with the driving side member and the contact portion with the valve side member are arranged on the same side with respect to the base portion.

  In the lubrication structure of the valve operating apparatus, as shown in claim 2, the diameter of the driven oil supply passage may be larger than the diameter of the drive oil supply passage.

  According to this, the supply amount of the drive side oil passage and the driven side oil passage can be optimized. Since the centrifugal force acts on the lubricating oil in the drive-side oil passage that extends in the substantially radial direction due to the rocking motion of the rocker arm, the supply amount tends to increase. By making it larger than the diameter of the oil supply passage, it is possible to avoid excessive supply of lubricating oil to the contact portion with the drive side member and to avoid insufficient lubrication of the contact portion with the valve side member. .

  In the lubrication structure of the valve operating device, as shown in claim 3, the rocker arm is configured to guide the lubricant discharged from the driven side oil supply passage to a contact portion with the valve side member. The (corner portion 54) may be provided on the valve side surface.

  According to this, the lubricating oil can be reliably supplied to the contact portion with the valve side member without opening the outlet of the driven oil supply passage in the vicinity of the contact portion with the valve side member.

  In this case, the lubricating oil guiding means is provided with a recess on the valve side surface of the rocker arm so as to extend from the vicinity of the outlet of the driven side oil supply passage opened to the contact portion with the valve side member. It is preferable that the corner is formed. According to this, the lubricating oil is guided to the contact portion with the member on the valve side along the wall without splashing the lubricating oil.

  In the lubricating structure of the valve operating apparatus, as shown in claim 4, the cylinder has a link mechanism for each cylinder for changing the valve opening characteristics, and members (gear link 21 and roller link 22) constituting the link mechanism. ) May be provided in the vicinity of the rocker arm.

  According to this, there are few gaps around the rocker arm due to the members constituting the link mechanism, and the contact part with the valve side member is hidden, but the contact part with the valve side member is driven. Since lubricating oil is supplied from the side oil supply passage, insufficient lubrication can be avoided.

  As described above, according to the present invention, the lubricating oil is supplied to the contact portion with the drive side member and the contact portion with the valve side member, which are the lubrication target portions, by the drive side oil supply passage and the driven side oil supply passage. Therefore, stable and reliable lubrication is possible regardless of the operating conditions. Since the contact portion with the valve side member and the contact portion with the drive side member are lubricated, the wear resistance of the drive side member is improved, and the valve side member is seized. Problems can be prevented. In addition, since the drive-side oil supply passage and the driven-side oil supply passage are partially shared, the number of processing steps can be reduced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a perspective view showing an upper portion of an engine according to the present invention. FIG. 2 is a perspective view showing a valve opening characteristic variable mechanism of the engine shown in FIG. FIG. 3 is a vertical cross-sectional view showing an operation state of the variable valve opening characteristic mechanism shown in FIG.

  This engine (variable valve opening characteristic internal combustion engine) is an in-line four-cylinder engine mounted on an automobile. The cylinder head 1 includes two exhaust valves 2 for each cylinder. As a valve operating mechanism for driving the cam 2, a camshaft 4 having a cam 3, a rocker arm 6 interposed between the valve 2 and the cam 3, and a valve spring 7 for constantly urging the valve 2 in the closing direction are provided. Is provided.

  Although not shown, on the intake side, two intake valves are provided for each cylinder, and a camshaft, a rocker arm, and a valve spring are provided as valve operating mechanisms for driving the valves. Yes.

  The cam shaft 4 is rotatably supported by the cam holder 11. The cam holder 11 is provided so as to partition a valve operating chamber for each cylinder, and is fastened and fixed to the upper surface of the cylinder head 1 with a bolt.

  This engine is equipped with a variable valve opening characteristic mechanism that variably controls the lift amount of the valve 2. In this variable valve opening characteristic mechanism, a gear shaft (control shaft) that causes the link mechanism 15 provided for each cylinder to operate in an interlocked manner via a reduction gear mechanism (not shown) by an electric motor 14 installed on the upper surface of the base plate 13. 16 is rotationally driven. This gear shaft 16 is also rotatably supported by the cam holder 11.

  As shown in FIG. 2, the link mechanism 15 constituting the valve opening characteristic variable mechanism includes a gear link 21 that is rotatably supported by the cam holder 11, and is swingably held by the gear link 21. It has a roller link 22 interposed between the cam 3 and the rocker arm 6 on the end side, and the lift amount of the valve 2 is adjusted according to the displacement of the swing fulcrum of the roller link 22 as the gear link 21 rotates. It is supposed to change.

  The gear link 21 extends in the circumferential direction from an arm portion 24 that rotates around a support shaft 23 provided in the cam holder 11, and the gear 17 of the gear shaft 16 (FIG. 1). And a gear portion 25 that meshes with each other, and rotates by the driving force of the electric motor 14. Further, a bearing portion 26 that holds the roller link 22 in a swingable manner is formed on the side surface on the free end side of the arm portion 24 so as to protrude in the axial direction. The gear portion 25 of the gear link 21 and the cam holder 11 are in slidable contact with each other in the axially opposed surface.

  The roller link 22 is fitted to the bearing portion 26 of the gear link 21, and a base portion 28 provided with a support shaft portion 27 serving as a swing fulcrum at both ends, and a pair of arm portions 29 extending from the base portion 28. And have. At the tip of the arm portion 29, there are a roller 31 that is in rolling contact with the cam 3 of the camshaft 4, and a roller shaft 32 that is in rolling contact with the slipper surface of the rocker arm 6.

  The rocker arm 6 includes a base portion 35 rotatably supported by a rocker shaft 34 held by the cam holder 11, and a pair of arm portions 36 extending from the base portion 35, and the pair of arms As shown in FIG. 3, each of the portions 36 is provided with an adjusting screw 39 for adjusting the position of a tip portion 38 that presses the stem end 37 of the valve 2.

  In the valve opening characteristic variable mechanism configured as described above, the gear link 21 rotates about the support shaft 23 (see FIG. 2) as the gear shaft 16 rotates, and the roller is accordingly generated. The bearing portion 26 serving as a swing fulcrum of the link 22 is displaced, and the lift amount of the valve 2 can be adjusted steplessly according to the rotation angle position (link angle) of the gear link 21.

  When reducing the valve lift during idling or the like, the gear link 21 is set to the minimum lift position (for example, link angle = 0 degree) shown in FIG. 3A, and in this case, it becomes the swing fulcrum of the roller link 22. Even if the bearing portion 26 is located above the camshaft 4 and the roller 31 is pushed down by the cam 3, the roller shaft 32 rolls along the slipper surface 33 as shown by the arrow, thereby causing the rocker arm 6 to swing. The amount of movement (that is, the lift amount of the valve 2) becomes small.

  On the other hand, when increasing the valve lift during high load operation or the like, the gear link 21 is set to the maximum lift position (for example, link angle = 60 degrees) shown in FIG. 3B, and in this case, the roller link 22 is swung. When the bearing 26 serving as a fulcrum is located on the side of the camshaft 4 and the roller 31 is pushed down by the cam 3, the roller shaft 32 hardly rolls along the slipper surface 33. Increased lift.

  As described above, the link mechanism 15 for each cylinder is provided in order to change the valve opening characteristic of the valve 2, and the gear link 21 and the roller link 22 constituting the link mechanism 15 are in the vicinity of the rocker arm 6. Since there is little clearance around the rocker arm 6 and the tip portion 38 with which the stem end 37 of the valve 2 comes into contact is hidden, the lubricating oil is supplied to the rocker arm 6 as described below. A mechanism is provided to avoid insufficient lubrication.

  FIG. 4 is a perspective view showing the rocker arm 6 shown in FIG. FIG. 5 is a perspective view showing a surface of the rocker arm 6 shown in FIG. 2 on the valve 2 side.

  As shown in FIG. 4, the rocker arm 6 has a slipper surface that extends in a substantially radial direction from a center hole 41 of a base portion 35 that is formed in a hollow shape and a roller shaft (drive-side member) 32 (see FIG. 3) contacts. A slipper surface oil supply hole (drive side oil supply passage) 42 for supplying lubricating oil to 33, and a tip portion that branches from the middle of the slipper surface oil supply hole 42 and contacts the stem end (valve side member) 37 of the valve 2. 38 (see FIG. 3) is provided with a tip portion oil supply hole (driven oil supply passage) 43 for supplying lubricating oil.

  A rocker shaft 34 is fitted into the center hole 41 of the base 35, and the lubricating oil flowing through the oil feed passage 44 inside the rocker shaft 34 is discharged from an oil supply hole 45 that opens to the outer peripheral surface of the rocker shaft 34. It flows into the surface oil supply hole 42. It is also possible to adopt a configuration in which the lubricating oil is introduced into the oil feeding passage provided inside the base 35 and sent to the slipper surface oil supply hole 42 without using the rocker shaft 34.

  The slipper surface oil supply hole 42 is formed with a small diameter, and the tip portion oil supply hole 43 is formed with a larger diameter than the slipper surface oil supply hole 42, thereby lubricating the slipper surface oil supply hole 42 and the tip portion oil supply hole 43. The amount of oil supply can be optimized. Since the centrifugal force acts on the lubricating oil in the slipper surface oil supply hole 42 extending in the substantially radial direction due to the rocking motion of the rocker arm 6, the supply amount tends to increase, and the diameter of the tip oil supply hole 43 is increased. By making it larger than the diameter of the slipper surface oil supply hole 42, it is possible to avoid excessive lubrication oil being supplied to the slipper surface 33 and to avoid insufficient lubrication of the tip portion 38.

  On the valve 2 side surface of the rocker arm 6, as shown in FIG. 5, a recess 52 is formed in a region from the base portion 35 to the screw holding portion 51 for holding the adjustment screw 39 in the arm portion 36. The recess 52 is surrounded on three sides by the side wall surfaces 52a and 52b on both sides and the wall surface 52c on the screw holding portion 51 side, and a corner portion (lubricating oil guiding means) composed of one side wall surface 52a and the bottom surface 52d. 54 is formed in the range from the base 35 side to the screw holding part 51 along the side wall surface 52a.

  In the vicinity of one side wall surface 52a of the bottom surface 52d of the recess 52, an outlet of the tip portion oil supply hole 43 is opened, and the lubricating oil discharged from the outlet of the tip portion oil supply hole 43 is indicated by an arrow in the figure. As shown, the tip portion 38 is guided along the corner 54 along the wall. Therefore, the lubricating oil discharged from the outlet of the tip portion oil supply hole 43 can reliably reach the tip portion 38 without being scattered and lubricate the tip portion 38 and the stem end 37 of the valve 2.

  In the above example, the roller shaft held by the roller link constituting the valve opening characteristic variable mechanism is abutted on the rocker arm as the drive side member. However, the present invention is not limited to this. Various aspects such as a configuration in which the valve cam directly contacts the rocker arm are possible.

It is a perspective view which shows the upper part of the engine by this invention. It is a perspective view which shows the valve opening characteristic variable mechanism of the engine shown in FIG. It is a longitudinal cross-sectional view which shows the operation condition of the valve opening characteristic variable mechanism shown in FIG. FIG. 3 is a perspective view showing the rocker arm shown in FIG. It is a perspective view which shows the surface by the side of the valve | bulb of the rocker arm shown in FIG.

Explanation of symbols

2 Valve 3 Cam 4 Camshaft 6 Rocker arm 14 Electric motor 15 Link mechanism 21 Gear link 22 Roller link 31 Roller 32 Roller shaft (drive-side member)
33 Slipper surface 34 Rocker shaft 35 Base portion 36 Arm portion 37 Stem end (member on the valve side)
38 Tip part 39 Adjustment screw 42 Slipper surface oil supply hole (drive side oil supply path)
43 Tip oil supply hole (driven oil supply path)
44 Oil supply path 51 Screw holding portion 52 Recess, 52a / 52b Side wall surface, 52c Wall surface, 52d Bottom surface 54 Corner

Claims (4)

In an internal combustion engine, a lubrication structure for a valve operating apparatus having a rocker arm that contacts a valve side member that performs intake or exhaust and a drive side member and opens and closes the valve according to the operation of the drive side member. There,
The valve extends from the inside of the base portion of the rocker arm in a substantially radial direction and supplies a lubricating oil to a contact portion with the driving side member, and branches from the middle of the driving side oil supply passage. A lubrication structure for a valve operating apparatus, comprising a driven-side oil supply passage for supplying lubricating oil to a contact portion with a side member.   The lubrication structure for a valve operating apparatus according to claim 1, wherein a diameter of the driven side oil supply passage is larger than a diameter of the drive side oil supply passage.   The said rocker arm has a lubricating oil guiding means for guiding the lubricating oil discharged from the driven oil supply passage to a contact portion with the valve side member on the valve side surface. Or the lubricating structure of the valve operating apparatus of Claim 2.   4. A link mechanism for each cylinder for changing valve opening characteristics, and a member constituting the link mechanism is provided in the vicinity of the rocker arm. 2. The lubricating structure of the valve operating device according to 1.

Images