JP4762963B2 - Variable valve opening characteristics internal combustion engine - Google Patents

Description

  The present invention relates to a variable valve opening characteristic internal combustion engine in which valve opening characteristics such as a lift amount of a valve can be changed according to an operating state.

  In recent years, internal combustion engines such as gasoline engines and diesel engines are increasingly equipped with various valve opening characteristic variable mechanisms in order to improve output and fuel consumption and reduce harmful exhaust gas components. As a valve opening characteristic variable mechanism, there is a mechanism that switches between a low speed type cam and a high speed type cam according to the operating condition, but in recent years it has been opened in order to further improve the transient characteristics and reduce the throttle. Some have continuously changed the valve characteristics (valve lift and valve timing).

In this type of variable valve opening characteristic internal combustion engine, a configuration in which the valve opening characteristic is changed using a link mechanism is often used. In this case, it is necessary to supply lubricating oil to the connecting portion between the link members. For example, a lubricating oil passage is provided inside the control shaft that operates the link mechanism of each valve in an interlocked manner, and a lubricating oil discharge hole that communicates with this is opened on the outer peripheral surface of the control shaft to supply lubricating oil to the link mechanism The technique made to do is known (refer patent document 1).
JP 2007-113529 A

  However, in the conventional technique, since the lubricating oil passage is provided inside the long shaft extending long in the lateral direction, the degree of freedom in design in the layout surface is reduced, and the processing at the time of manufacture becomes complicated. In order to ensure the required rigidity, there arises a problem of increasing the size and weight.

  Further, when the valve opening characteristic variable mechanism is configured to move the lubrication target part away from the shaft provided with the lubricant passage according to the operation of changing the valve lift amount, it is difficult to supply the lubricant to the lubrication target part. Therefore, there is a problem that stable lubricity cannot be ensured.

  The present invention has been devised to solve such problems of the prior art, and its main purpose is to reduce the degree of freedom in design in terms of layout, to complicate processing during manufacture, An object of the present invention is to provide a variable valve opening characteristic internal combustion engine configured to avoid an increase in size and weight. Furthermore, the present invention enables the supply of lubricating oil to the lubrication target site to be stably supplied to the lubrication target site without changing according to the operation of changing the valve opening characteristics. Also aimed.

In order to solve such a problem, in the present invention, as shown in claim 1, a first member that is rotatably supported by a support member (cam holder 11) and is driven by an actuator (electric motor 14). A control member (gear link 21) and a second control which is swingably held by the first control member and has a free end interposed between the valve (2) and the valve cam (3). And a valve opening amount that changes the lift amount of the valve in accordance with the displacement of the swing fulcrum of the second control member accompanying the rotation of the first control member. In the variable characteristic internal combustion engine, the first control member and the support member are slidably brought into contact with surfaces (side surface 25a, side surface 11a) facing the rotation center axis direction of the first control member. , At least one of its opposite surfaces It was assumed that the swing fulcrum portion recess lubricating oil (the bearing portion 26) to lubricate a supply path for supplying from the support member side of the second control member (oil groove 51) has been formed.

  According to this, the lubricating oil is supplied from the supporting member side to the oscillating fulcrum portion of the second control member serving as the lubrication target portion via the oil supply passage formed between the opposing surfaces of the first control member and the supporting member. The first control member and the support member may be provided with a recess serving as an oil supply passage and a hole as required, and the first control member and the support member may be provided with a member extending long in the lateral direction, such as a control shaft. Since there is no need to provide a path, the design freedom in layout is increased, the processing at the time of manufacture is simplified, and the rigidity of the part is not impaired, so the part can be reduced in size and weight. Become.

  In the variable valve opening characteristic internal combustion engine, as shown in claim 2, an oil supply hole (41) for discharging lubricating oil is opened on a surface (side surface 11a) of the support member facing the first control member. Then, an arc-shaped oil supply groove (51) centering on the rotation center of the first control member is formed as the recess on the surface (side surface 25a) of the first control member facing the support member. The structure may be formed corresponding to the oil supply hole of the support member.

  According to this, since the oil supply hole on the support member side and the oil supply groove on the first control member side are always aligned regardless of the rotation angle position of the first control member, the lubricating oil from the support member side Supply is performed without stagnation and reliable lubrication is possible.

  In this case, it is preferable that the oil supply hole on the support member side is located at a position higher than at least a part of the swing fulcrum portion of the second control member, which is a lubrication target portion, so that reliable lubrication can be achieved even at low oil pressure. It becomes possible.

  In the variable valve opening characteristic internal combustion engine, as shown in claim 3, the first control member is urged toward the support member, and the opposed surfaces of the first control member and the support member are pressed against each other. It can be set as the structure provided with the urging means (coil spring 61) hold | maintained in the state which carried out.

  According to this, the clearance between the opposing surfaces of the first control member and the support member can be eliminated, and leakage of the lubricating oil can be avoided, and reliable lubrication is possible. In addition, it is possible to position the first control member itself in the thrust direction.

  As described above, according to the present invention, the swing fulcrum portion of the second control member that becomes the lubrication target portion from the support member side via the oil supply passage formed between the opposing surfaces of the first control member and the support member. The first control member and the support member may be provided with a recess serving as an oil supply passage and a hole as necessary, and the first control member and the support member may extend in the lateral direction as in the control shaft. Since there is no need to provide oil supply passages on existing members, the design flexibility in layout is increased, the processing during manufacturing is simplified, and the rigidity of the components is not impaired. Weight reduction is possible.

  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 type 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 a cam holder (support member) 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, an electric motor (actuator) 14 installed on the upper surface of the base plate 13 is used to link the link mechanism 15 provided for each cylinder via a reduction gear mechanism (not shown). The control shaft 16 is driven to rotate. 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 (first control member) 21 rotatably supported by a cam holder (support member) 11, and the gear link 21. And a roller link (second control member) 22 interposed between the cam 3 and the rocker arm 6 on the free end side, and accompanying the rotation of the gear link 21 The lift amount of the valve 2 is changed in accordance with the displacement of the swing fulcrum of the roller link 22.

  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 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 part 36 is provided with an adjusting screw 39 for adjusting the position of a tip part 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.

  FIG. 4 is a perspective view showing a main part of the variable valve opening characteristic mechanism shown in FIG. FIG. 5 is a perspective view showing the gear link shown in FIG. FIG. 6 is a side view showing an operation state of the gear link shown in FIG.

  As shown in FIG. 4, on the side surface 11 a of the cam holder 11 (the surface facing the gear link 21), lubricating oil for lubricating the swing fulcrum portion of the roller link 22, that is, the interior of the bearing portion 26, is provided on the gear link 21. The oil supply hole 41 which supplies to is formed. The oil supply hole 41 communicates with an oil supply hole 43 opened on the inner peripheral surface of the bearing portion 42 that rotatably supports the camshaft 4, and the lubricating oil flowing through the camshaft 4 opens on the outer peripheral surface thereof. After discharging from the oil supply hole, the oil is discharged from the outlet of the oil supply hole 41 through the oil supply hole 43.

  On the other hand, as shown in FIG. 5, a side surface (a surface facing the cam holder 11) 25 a of the gear portion 25 of the gear link 21 has an arcuate oil supply groove that receives the lubricating oil discharged from the oil supply hole 41 of the cam holder 11. (Recess) 51 is provided. An oil supply hole 52 that guides lubricating oil into the bearing portion 26 is formed in the axial direction at a substantially central position of the bearing portion 26. Further, on the side surface of the gear portion 25 of the gear link 21, a linear oil supply groove 53 that connects the oil supply hole 52 and the arcuate oil supply groove 51 extends in the radial direction of the bearing portion 26. Lubricating oil introduced into the oil supply groove 51 from the oil supply hole 41 flows into the oil supply hole 52 through the oil supply groove 53 and is sent into the bearing portion 26.

  As shown in FIG. 4, the oil supply hole 52 of the bearing portion 26 has an outlet opening at the bottom surface of the bearing portion 26, and is between the bottom surface of the bearing portion 26 and the end surface of the support shaft portion 27 of the roller link 22. In this case, a vacant chamber 55 in which lubricating oil is stored is defined, and the lubricating oil is supplied to the inner peripheral surface of the bearing portion 26 of the gear link 21 and the outer peripheral surface of the support shaft portion 27 of the roller link 22 that slide with each other. The

  As shown in FIG. 6, the arc-shaped oil supply groove 51 provided on the side surface of the gear link 21 extends in an arc shape around the support shaft 23 of the gear link 21, and is related to the angular position of the gear link 21. However, it is always aligned with the oil supply hole 41 on the cam holder 11 side, so that the supply of lubricating oil from the cam holder 11 side is performed without stagnation.

  In addition, in the minimum lift position indicated by A in FIG. 6 (for example, the link angle = 0 degree), the oil supply hole 41 on the cam holder 11 side is a part of the inner peripheral surface of the bearing portion 26 of the gear link 21 that is a lubrication target site, That is, when the gear link 21 is rotated toward the maximum lift position (for example, link angle = 60 degrees) indicated by B in FIG. 6 at a position higher than the lowermost portion of the inner peripheral surface of the bearing portion 26, the cam holder 11. The side oil supply hole 41 is positioned higher than the entire inner peripheral surface of the bearing portion 26. For this reason, lubricating oil can be reliably supplied to the inside of the bearing portion 26 of the gear link 21 even at low oil pressure.

  Further, as shown in FIG. 4, the gear link 21 is urged toward the cam holder 11 inside the bearing portion 26 of the gear link 21, and the side surface 25 a of the gear link 21 and the side surface 11 a of the cam holder 11 are pressed against each other. A coil spring (biasing means) 61 is provided to maintain the state, whereby a gap between the side surface 25a of the gear link 21 and the side surface 11a of the cam holder 11 can be eliminated, and leakage of lubricating oil can be avoided. Reliable lubrication is possible. In addition, the gear link 21 itself can be positioned in the thrust direction.

  In particular, here, the coil spring 61 has one end abutting on the bottom surface of the bearing portion 26 of the gear link 21 and the bottom surface of the bottomed spring accommodating hole 62 that is recessed in the axial direction on the support shaft portion 27 of the roller link 22. The other end is in contact with the roller link 22 and the gear link 21 is assembled in a compressed state. Further, a pair of gear links 21 are provided on both sides of the roller link 22 (see FIG. 2), and the coil springs 61 provided on the support shaft portions 27 on both sides of the roller link 22 are opposite to each other. The gear link 21 is urged in the direction so that the side surface 25a of the gear link 21 is pressed against the side surface 11a of the cam holder 11 facing each other.

  Further, the base portion 28 of the roller link 22 is provided with a communication hole 63 penetrating in the axial direction, and the communication hole 63 communicates the vacant chamber 55 and the spring accommodation hole 62 provided on both sides of the base portion 28 with each other. The For this reason, the oil supply hole 41 of the cam holder 11 and the oil supply groove 51, the oil supply hole 52, and the oil supply groove 53 of the gear link 21 are provided only on one side of the gear link 21 and the cam holder 11 on both sides of the roller link 22. Lubricating oil sent from one side can also lubricate the bearing portions 26 of the gear links 21 on both sides.

  In the above example, the oil supply groove 51 is provided on the gear link (first control member) 22 side as a recess serving as a lubricant supply path, but the lubricant oil is provided on the cam holder (support member) 11 side. It is also possible to provide a recess serving as a supply path.

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 a main part of the variable valve opening characteristic mechanism shown in FIG. It is a perspective view which shows the gear link shown in FIG. It is a side view which shows the operation | movement condition of the gear link shown in FIG.

Explanation of symbols

2 Valve 3 Cam 4 Camshaft 6 Rocker arm 11 Cam holder (support member), 11a Side surface 14 Electric motor (actuator)
15 Link mechanism 21 Gear link (first control member)
22 Roller link (second control member)
23 Support shaft 24 Arm portion 25 Gear portion, 25a Side surface 26 Bearing portion 27 Support shaft portion 28 Base portion 29 Arm portion 41 Oil supply hole 51 Oil supply groove (recess)
52 Oil supply hole 53 Oil supply groove 61 Coil spring (biasing means)

Claims (3)

A first control member that is rotatably supported by the support member and is driven by an actuator, and is swingably held by the first control member, and a free end is disposed between the valve and the valve cam. An intervening second control member, and the lift amount of the valve is changed according to the displacement of the swing fulcrum of the second control member as the first control member rotates. A variable valve opening characteristic internal combustion engine,
The first control member and the support member are slidably brought into contact with a surface facing the rotation center axis direction of the first control member, and at least one of the facing surfaces is contacted with the second A variable valve opening characteristic internal combustion engine, wherein a recess serving as a supply path for supplying lubricating oil for lubricating the swing fulcrum portion of the control member from the support member side is formed.   An oil supply hole for discharging lubricating oil is opened on the surface of the support member facing the first control member, and the recess is formed on the surface of the first control member facing the support member as the recess. 2. The variable valve opening characteristic internal combustion engine according to claim 1, wherein an arcuate oil supply groove centering on a rotation center of one control member is formed corresponding to an oil supply hole of the support member. .   The urging means for urging the first control member toward the support member and holding the opposed surfaces of the first control member and the support member in pressure contact with each other is provided. The variable valve opening characteristic type internal combustion engine according to claim 1 or 2.

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