JP2008050974A - Variable valve gear for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve wear resistance by efficiently lubricating sliding parts of a shim and a mediating drive mechanism. <P>SOLUTION: A variable valve gear 1 is provided with an output part 31 and an input part 21 supported to be rockable in line by a support pipe 20x fixed on a vertical wall part 5 provided in parallel, includes the mediating drive mechanism 20 driving a valve 6 by the output part 31 when the input part 21 is driven by a rotary cam 10, and a rotation phase difference variable mechanism 41 varying relative rotation phase difference between the input part 21 and the output part 31, adjusts a position of the mediating drive mechanism 20 by including an inclusion part 51 of a shim 50 between the vertical wall part 5 and the mediating drive mechanism 20, and supplies lubricating oil 73 to the sliding parts of the shim 50 and the mediating drive mechanism 20. A plurality of dimples 52 are provided on at least one of a surface 50s of the shim and an end surface 32s of the mediating drive mechanism. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a variable valve mechanism for an internal combustion engine that lubricates a sliding portion.

2. Description of the Related Art Conventionally, a variable valve mechanism that can continuously change a valve lift amount in an internal combustion engine of an automobile is known. Patent Document 1 includes an input unit and an output unit supported in a swingable manner on a support pipe fixed to a standing wall portion provided side by side, and when the input unit is driven by a rotating cam, the output unit Describes a variable valve mechanism that includes an intermediary drive mechanism that drives a valve at, and a rotation phase difference variable mechanism that varies a relative rotation phase difference between the input unit and the output unit. In Patent Document 2 and Patent Document 3, a shim is interposed between the end face of the mediation drive mechanism and the standing wall portion in order to increase the variable accuracy, and the axial position of the mediation drive mechanism can be finely adjusted with the shim. A variable valve mechanism is described. In such a variable valve mechanism, since the shim is considered not to receive much axial force, the sliding portion of the shim has not been sufficiently lubricated.
JP 2001-263015 A JP 2005-226604 A JP 2005-163703 A

  However, it has been found that when the input portion and the output portion are swung, the parallelism with respect to the axial direction of the rollers, cams and the like is shifted, and the shim is worn by receiving the axial force. Patent Documents 1 and 2 have no description regarding shim lubrication. Further, the variable valve mechanism of Patent Document 3 equipped with a shim lubrication device sprays lubricating oil throughout, and even when applied to a variable valve mechanism equipped with a shim, supply of the lubricating oil to the shim The amount is limited, and there is a problem that a great lubrication effect cannot be obtained.

  Accordingly, an object of the present invention is to provide a variable valve mechanism for an internal combustion engine in which the sliding portion between the shim and the intermediate drive mechanism is efficiently lubricated to improve wear resistance.

  In order to achieve the above object, a variable valve mechanism for an internal combustion engine according to the present invention includes an input unit and an output unit supported in a swingable manner on a support pipe fixed to a standing wall portion provided in parallel, When the input unit is driven by a rotating cam, an intermediate drive mechanism that drives a valve by the output unit, and a rotation phase difference variable mechanism that varies a relative rotation phase difference between the input unit and the output unit. A position of the mediation drive mechanism is adjusted by interposing a shim interposition portion between the standing wall portion and the mediation drive mechanism, and the sliding portion between the shim and the mediation drive mechanism is lubricated. In the variable valve mechanism for an internal combustion engine that supplies oil, a concave oil sump for storing the lubricating oil is provided on at least one of an end face of the intermediate drive mechanism and a surface of the shim.

  As a method for lubricating the sliding portion between the shim and the intermediate drive mechanism with lubricating oil, for example, a lubricating oil injection device is provided above the sliding portion, and the lubricating oil is poured into the sliding portion.

Although the said oil sump is not specifically limited, The following (i) and (ii) are illustrated.
(I) The oil reservoir is a plurality of dimples. The diameter of the dimple is preferably 0.1 to 3 mm, the depth is preferably 5 to 1000 μm, and the total area occupied by the dimple is preferably 5 to 45% of the one side surface of the shim. The method for forming the dimple is not particularly limited, and examples thereof include shot peening and pressing. Further, particularly in a portion where sliding friction is increased, the dimple density formed in the portion may be increased so that a large amount of lubricating oil may be accumulated, and the effects of the present invention can be obtained reasonably and effectively. it can.

(Ii) A plurality of grooves intersecting the oil sump. The width of the groove is preferably 0.1 to 3 mm, the depth is preferably 5 to 1000 μm, the distance between the grooves is preferably 0.5 to 10 mm, and the total area occupied by the groove is 5 to 45 of the one side surface of the shim. % Is preferred. Although the formation method of a groove | channel is not specifically limited, Texture processing, cutting processing, etc. are illustrated. Further, although not particularly limited, the grooves may intersect in a lattice shape, or may intersect at a free angle. In particular, in a portion where the sliding friction is increased, the interval between the groove lattices may be narrowed so that a large amount of lubricating oil is accumulated, and the effects of the present invention can be obtained reasonably and effectively.

  According to the variable valve mechanism for an internal combustion engine of the present invention, the sliding portion can be maintained in a lubricated state for a long period of time by accumulating lubricating oil in the oil reservoir. Efficient lubrication can improve wear resistance.

  A variable valve mechanism 1 for an internal combustion engine 2 according to the present invention includes an input portion 21 and an output portion 31 that are swingably supported side by side on a support pipe 20x fixed to a standing wall portion 5 provided in parallel. When the input unit 21 is driven by 10, the intermediate drive mechanism 20 that drives the valve 6 by the output unit 31, and the rotation phase difference variable mechanism 41 that varies the relative rotation phase difference between the input unit 21 and the output unit 31. And the position of the mediation drive mechanism 20 is adjusted by interposing the intervening portion 51 of the shim 50 between the standing wall portion 5 and the mediation drive mechanism 20, and the sliding between the shim 50 and the mediation drive mechanism 20 is adjusted. In the variable valve mechanism 1 of the internal combustion engine 2 for supplying the lubricating oil 73 to the moving part, a plurality of dimples 52 for storing the lubricating oil 73 are provided on at least one of the end face 32s and the shim surface 50s of the intermediate drive mechanism.

  A first embodiment of the present invention will be described in detail with reference to FIGS. The variable valve mechanism 1 of the present embodiment includes an input portion 21 and an output portion 31 that are supported by a support pipe 20x fixed to a standing wall portion 5 arranged side by side so as to be swingable. The intermediate drive mechanism 20 that drives the valve 6 by the output unit 31 when the unit 21 is driven, and the rotation phase difference variable mechanism 41 that varies the relative rotation phase difference between the input unit 21 and the output unit 31. The position of the mediation drive mechanism 20 is adjusted by the interposition of the shim 50 between the standing wall 5 and the mediation drive mechanism 20, and the sliding portion between the shim 50 and the mediation drive mechanism 20 is adjusted. In the variable valve mechanism 1 of the internal combustion engine 2 for supplying the lubricating oil 73, the lubricating oil injection device 70 is provided above the sliding portion, and a plurality of dimples 52 are formed on the surface 50 s on the sliding portion side of the shim 50. is doing.

  Hereinafter, for convenience of explanation, one of the longitudinal directions of the support pipe 20x is defined as the front F, the other is defined as the rear R, and the mediation drive mechanism 20 presses the rocker arm 15 in the circumferential direction of the support pipe 20x. The direction in which the valve 6 opens is defined as the opening direction O, and the opposite direction as the closing direction C.

  The shim 50 is formed by processing a metal plate, and includes an interposing portion 51 formed in a U shape for allowing the support pipe 20x to pass. The shim 50 is used on the outer side of the U shape to prevent the shim from rotating. A convex portion 56 is formed. A plurality of dimples 52 are formed by shot peening on the surface of the intervention part 51 on the side of the mediation drive mechanism.

  The dimples 52 are formed so as to be scattered over substantially the entire interposition part 51. Specifically, the dimple has a diameter of 1 mm and a depth of 10 μm, and the total area occupied by the dimple is approximately 10% of the one side surface of the shim. In addition, the density of the dimple 52 of the present invention is not particularly limited, and can be changed so that the density of the portion where the sliding friction is large can be increased and the lubricating oil 73 can be partially accumulated.

  The lubricating oil injection device 70 includes a reservoir 71 for storing the lubricating oil 73 and an injection port 72 for injecting the lubricating oil 73 provided in the reservoir 71, and is attached to the head cover 7 above the sliding portion. Yes.

  The support pipe 20x is a single pipe shared by a plurality of variable valve mechanisms 1 in the internal combustion engine, and a plurality of support pipes 20x arranged in parallel in the front and rear directions F and R at an upper portion of the cylinder head 4. It is being fixed to the standing wall part 5 so that rotation is impossible. The support pipe 20x has a long hole 20h that is long in the front-rear directions F and R, and allows a pin 42p to be inserted into a hole 42h of a control shaft to be described later.

  The input unit 21 is disposed substantially at the center between two adjacent standing wall portions 5. The input portion 21 includes a base cylindrical portion 22 as a basic portion, a pair of input arms 23 protruding from the outer peripheral surface of the base cylindrical portion 22, a cam shaft 24 held by the input arm 23, and the cam shaft 24. And a return arm 26 projecting from the outer peripheral surface of the base cylindrical portion 22 on the opposite side of the input arm 23. A shaft hole for inserting the support pipe 20x is formed in the center of the base cylindrical portion 22, and a space for holding the rotation phase difference variable mechanism 41 is provided inside the base cylindrical portion 22, and the base cylindrical portion An input portion helical spline 28 that meshes with a slider gear 43 of a rotation phase difference varying mechanism 41 (described later) is formed on the inner surface of 22. The roller 25 abuts on the cam surface 12s of the rotating cam 10 and can receive power transmitted by the rotational driving of the cam.

  One output portion 31 is disposed on each side of the input portion 21 in the front-rear direction F, R between two adjacent standing wall portions 5. Each output portion 31 includes a base cylindrical portion 32 serving as a basic portion, an output nose 33 protruding from the outer peripheral surface of the base cylindrical portion 32, and an output cam surface 33s that presses the roller 16 of the rocker arm 15 at the output nose 33. Consists of The output nose 33 is formed in a fin shape, and an output cam surface 33 s which is an outer peripheral surface thereof is in contact with the roller 16 of the rocker arm 15. Further, a shaft hole for inserting the support pipe 20x is formed in the center of the base cylindrical portion 32, and a space for holding the rotation phase difference varying mechanism 41 is provided inside the base cylindrical portion 32. An output portion helical spline 34 that meshes with a slider gear 43 of a rotation phase difference variable mechanism 41 described later is formed on the inner surface of 32. The output portion helical spline 34 is formed at an angle different from that of the input portion helical spline 28 described above.

  The rotation phase difference variable mechanism includes a slider gear 43 that engages helical splines having different angles from each other between the control shaft 42 inserted through the support pipe and the input portion 21 and the output portion 31, and a slider gear 43. A pin 42p used for connection with the control shaft 42 is included.

  The control shaft 42 is formed with a hole 42h into which the pin 42p is inserted in the radial direction. The inserted pin can slide the control shaft 42 in the support pipe 20x in the front-rear directions F and R, and the control shaft 42 Is prevented from sliding in the circumferential directions O and C with respect to the support pipe 20x.

  The slider gear 43 is inserted between the input portion 21 and the output portion 31 and the support pipe 20x, and is an input helical that meshes with the input portion helical spline 28 formed on the inner surface of the base cylindrical portion 22 of the input portion 21 described above. Between the spline 44 and the output helical spline 45 that meshes with the two output part helical splines 34 formed on the inner surface of the base cylindrical part 32 of the output part 31 at an angle different from that of the input part 21. The small-diameter portion 46 is included.

  The small diameter portion 46 has a long hole 46h that is long in the circumferential direction, and the pin 42p penetrates the long hole together with the support pipe 20x. The inserted pin prevents the slider gear 43 from sliding in the opening and closing directions O and C with respect to the control shaft 42 and sliding in the front and rear directions F and R.

  According to the above configuration, when the control shaft 42 is driven in the front and rear directions F and R by an actuator (not shown), the slider gear 43 swings the input portion 21 and the output portion 31 in the opposite directions, and the lift amount and opening / closing timing of the valve 6 are controlled. Can be changed continuously. However, when the control shaft 42 is driven to the front F, for example, the mediation drive mechanism 20 presses the front F-side shim 50, and the front F-side output portion 32s and the shim surface 50s are located between them. Sliding friction occurs. Further, since the rotation shafts of the rollers and cams of the input portion 21 and the output portion 31 do not completely coincide with the drive shaft of the control shaft 42, the shim 50 has a portion where a large sliding friction is generated. There is.

  In the variable valve mechanism 1, the sliding portion is lubricated by the lubricating oil injection device 70 to suppress sliding friction. Further, in the present embodiment, since the plurality of dimples 52 are formed in the shim 50, the sliding portion can be maintained in a lubricated state for a long time by temporarily storing the lubricating oil 73 in the dimple 52. The sliding portion with the mediation drive mechanism 20 can be efficiently lubricated to improve wear resistance.

  The variable valve mechanism 1 of the second embodiment has the same configuration as that of the first embodiment, but differs from the first embodiment in that the oil reservoir provided in the shim 50 is not a dimple 52 but a groove. As shown in FIG. 4C, a plurality of grooves 53 that intersect with each other are formed on the surface of the shim 50 of the present embodiment on the sliding portion side.

  The grooves 53 are formed so as to intersect in a lattice shape over substantially the entire interposition part 51 by embossing. Specifically, the width of the groove is 1 mm, the depth is 10 μm, and the interval is 1 mm. As shown in FIGS. 4E and 4F, the shape of the groove 53 includes a U-shaped cross section or a rounded corner of the groove. The interval between the plurality of intersecting grooves 53 of the present invention is not particularly limited, and is changed so that the interval between the grooves 53 where the sliding friction is large is reduced so that a large amount of lubricating oil 73 can be accumulated. it can.

  According to the above configuration, once the lubricating oil 73 is accumulated in the groove 53, the sliding portion can be maintained in a lubricated state over a long period of time. Therefore, the sliding portion between the shim 50 and the intermediate drive mechanism 20 is efficiently lubricated. Abrasion resistance can be improved.

  It should be noted that the present invention is not limited to the above-described embodiment, and can be appropriately modified and embodied without departing from the spirit of the invention. A plurality of dimples 52 or a plurality of intersecting intersections are formed on both sides of the shim 50. A groove 53 may be formed, and the shim 50 may be interposed between the input part and the output part. Also, as shown in FIGS. 4B and 4D, a plurality of dimples 35 or a plurality of intersecting grooves 36 are formed on the end surface of the input section 21 or the output section 31 that slides on the surface of the shim. May be.

It is a whole side view which shows the variable valve mechanism of the Example of this invention. It is a perspective view which shows the mediation drive mechanism, shim, and lubricating oil injection apparatus of the Example of this invention. It is a disassembled perspective view which shows the mediation drive mechanism of the Example of this invention. (A) of Example 1 of this invention is a front view which shows a shim, (b) is a perspective view which shows an output part. (C) of Example 2 is a front view showing a shim, (d) is a perspective view showing an output portion, and (e) and (f) are cross-sectional views showing grooves.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Variable valve mechanism 2 Internal combustion engine 5 Standing wall part 6 Valve 10 Rotating cam 20 Mediating drive mechanism 21 Input part 31 Output part 32s End surface 41 Turning phase difference variable mechanism 50 Shim 50s Surface 51 Interposition part 52 Dimple 73 Lubricating oil

Claims (3)

An input unit and an output unit supported in a swingable manner on a support pipe supported by standing wall portions arranged side by side are provided. When the input unit is driven by a rotating cam, the valve is driven by the output unit. Including a mediation drive mechanism and a rotation phase difference variable mechanism that varies a relative rotation phase difference between the input unit and the output unit, and a shim intervening portion is provided between the standing wall portion and the mediation drive mechanism. In the variable valve mechanism of the internal combustion engine in which the position of the intermediate drive mechanism is adjusted by being interposed, and lubricating oil is supplied to the sliding portion between the shim and the intermediate drive mechanism.
A variable valve mechanism for an internal combustion engine, wherein a concave oil sump for collecting the lubricating oil is provided on at least one of an end face of the intermediate drive mechanism and a surface of the shim.   The variable valve mechanism for an internal combustion engine according to claim 1, wherein the oil reservoir is a plurality of dimples.   The variable valve mechanism for an internal combustion engine according to claim 1, wherein the oil reservoir is a plurality of intersecting grooves.

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