JP2006322331A - Lubrication structure of rocker arm - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lubrication structure of a rocker arm capable of maintaining an excellent lubricating state with a rocker shaft during the start of an internal combustion engine. <P>SOLUTION: A groove 5 is formed in the inner peripheral surface of the bearing part 2 of the rocker arm 1 in which a pivotally supported rocker shaft 6 is inserted at a position set to a bottom part when the internal combustion engine is stopped extendedly in the axial direction of the rocker shaft 6. A predetermined amount of oil is securely reserved in the groove 5, and during the start of the internal combustion engine, the oil reserved in the groove 5 is immediately fed to wide area of the inner peripheral surface of the bearing part 2 of the rocker arm 1. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a rocker arm lubrication structure, and more particularly to a rocker arm lubrication structure capable of maintaining a good lubrication state with a rocker shaft when an internal combustion engine is started.

  A valve operating structure of an internal combustion engine such as an engine is composed of a cam 9, a rocker arm 1 and the like built in the valve operating chamber 10 as illustrated in FIG. The cylindrical rocker shaft 6 is inserted into and supported by the bearing portion 2 of the rocker arm 1 whose other end is a valve abutting portion 3 that abuts the valve 8. As the cam 9 rotates, both end portions of the rocker arm 1 swing around the rocker shaft 6 to open and close the valve 8, and the inner peripheral surface of the bearing portion 2 and the rocker shaft are opened during the swing. The outer peripheral surface of 6 is a sliding portion.

  Therefore, for example, oil is supplied to the hollow portion of the rocker shaft 6 from the outside by an oil pump or the like, and the oil flows out from the hollow portion of the rocker shaft 6 to the outer peripheral surface through a communication hole provided in the peripheral wall of the rocker shaft 6; A method is known in which a lubrication state is ensured by being supplied between the outer peripheral surface of the rocker shaft 6 and the inner peripheral surface of the bearing portion 2 of the rocker arm 1.

  This lubrication structure functions while the internal combustion engine is operating. However, when the internal combustion engine is stopped, the supply of oil from the outside to the valve operating chamber 10 is also stopped, and the outer peripheral surface of the rocker shaft 6 and the rocker arm 1 are stopped. The oil supplied between the inner peripheral surface of the bearing part 2 flows down to the outside, and the sliding part is in a state of oil shortage. When the internal combustion engine is started in this state, the sliding portion slides due to insufficient oil until the oil is supplied from the outside again by an oil pump or the like. There were problems such as adverse effects.

Various structures for solving such problems and ensuring a lubrication state between the rocker arm 1 and the rocker shaft 6 have been proposed (see, for example, Patent Documents 1 to 3). In these proposals, a groove for storing oil is provided on the inner peripheral surface of the bearing portion 2 of the rocker arm 1, and the oil stored in this groove is used to eliminate an oil shortage state at the start of the internal combustion engine. However, the grooves in Patent Documents 1 and 2 extend in the circumferential direction on the inner peripheral surface of the bearing portion 2, and there is a problem that the grooves do not spread widely to the sliding portion. There is a problem in that it is formed obliquely downward on the inner peripheral surface and cannot store a sufficient amount of oil. Therefore, with these proposals, it has been difficult to ensure a sufficient lubrication state when the internal combustion engine is started.
JP 2001-182513 A Japanese Patent No. 3150551 Japanese Utility Model Publication No. 55-108208

  An object of the present invention is to provide a rocker arm lubrication structure capable of maintaining a good lubrication state with a rocker shaft when an internal combustion engine is started.

  In order to achieve the above object, a lubricating structure for a rocker arm according to the present invention includes a bearing portion, and a rocker arm of an internal combustion engine that is pivotally supported by a rocker shaft that is inserted through the bearing portion so that its longitudinal end is swingable. In the lubricating structure, the gist is provided with a groove extending in the axial direction of the rocker shaft at a position on the inner peripheral surface of the bearing portion that becomes the bottom when the internal combustion engine is stopped.

  According to the lubricating structure of the rocker arm of the present invention, the internal combustion engine is stopped by providing a groove at a position that becomes the bottom when the internal combustion engine stops on the inner peripheral surface of the bearing portion of the rocker arm through which the rocker shaft that supports the shaft is inserted Even if the oil that lubricates the valve mechanism flows down to the outside, a predetermined amount of oil can be reliably accumulated in this groove.

  Since this groove extends in the axial direction of the rocker shaft, when the internal combustion engine is started, the oil accumulated in the groove is immediately and widely supplied to the inner peripheral surface of the bearing portion of the rocker arm, and the rocker arm And the rocker shaft can be kept in a good lubrication state, and the sliding portion is not adversely affected.

  Hereinafter, a rocker arm lubricating structure of the present invention will be described based on the embodiments shown in the drawings. FIG. 1 illustrates an outline of the lubricating structure of the present invention. As shown in the figure, the rocker arm 1 has an integrated cylindrical bearing portion 2, and is supported by a cylindrical rocker shaft 6 inserted through the bearing portion 2. A rocker arm 1 corresponding to the number of valves 8 is pivotally supported on one rocker shaft 6.

  The rocker arm 1 has one end portion as a valve abutting portion 3 and the other end portion as a cam abutting portion 4, and both ends thereof can swing up and down around a rocker shaft 6. A groove 5 is formed on the inner peripheral surface of the bearing portion 2, and one end side is an opening end 7 a below the valve contact portion 3, and the other end side is an opening end 7 b on the inner peripheral surface of the bearing portion 2. An oil supply path 7 that penetrates the rocker arm 1 is formed substantially horizontally.

  2 to 4 show the inner structure of the bearing portion 2. FIG. 2 is a sectional view taken along the line AA in FIG. 1, FIG. 3 is a sectional view taken along the line BB in FIG. The shape is shown. In FIG. 3, the rocker shaft 6 is omitted for illustration. A line segment VL in FIG. 4 indicates a vertical line passing through the center P of the bearing portion 2.

  As shown in FIG. 4, the groove 5 formed on the inner peripheral surface of the bearing portion 2 is at a position on a vertical line VL that passes through the center P of the bearing portion 2 that becomes the bottom of the bearing portion 2 when the internal combustion engine is stopped. Most preferred.

  Since a plurality of rocker arms 1 are pivotally supported by one rocker shaft 6, when the internal combustion engine is stopped, it is illustrated by a two-dot chain line in FIG. 4 depending on the position of the valve that each rocker arm 1 opens and closes. The circumferential position of the groove 5 of each rocker arm 1 is different.

  Therefore, in the present invention, the position that becomes the bottom of the bearing portion 2 when the internal combustion engine provided with the groove 5 is stopped means a range having a certain width. For example, as shown in FIG. The inner circumferential surface is within a range of a predetermined angle E that spreads evenly from the center P of 2 to both sides of the vertical line VL. This angle E is, for example, 40 ° or less.

  Moreover, the groove | channel 5 formed in the internal peripheral surface of the bearing part 2 is extended in the axial direction of the rocker shaft 6 so that it may illustrate in FIGS. 2-3, and has an elongated shape in the axial direction. .

  As shown in FIGS. 1 and 3, the oil supply path 7 has a position of the opening end 7b on the other end side that is different from the groove 5 and is disposed above the groove 5 in the circumferential direction. Oil that has flowed down from the end 7 b is likely to accumulate in the groove 5.

  Due to the groove 5 and the oil supply passage 7 provided on the inner peripheral surface of the bearing portion 2 as described above, the inner peripheral surface of the bearing portion 2 from the outside of the rocker arm 1 through the oil supply passage 7 and the like during operation of the internal combustion engine. The oil is supplied to the inner peripheral surface of the bearing portion 2 serving as a sliding portion and the outer peripheral surface of the rocker shaft 6 is maintained in a lubricated state.

  On the other hand, when the internal combustion engine stops, the supply of oil from the oil supply path 7 and the like also stops, and the oil between the inner peripheral surface of the bearing portion 2 and the outer peripheral surface of the rocker shaft 6 flows down to the outside. Since 5 is located at the bottom of the inner peripheral surface of the bearing portion 2, a predetermined amount of oil can be reliably accumulated.

  Further, since this groove 5 extends in the axial direction of the rocker shaft 6 to be inserted, when the internal combustion engine is started, the oil accumulated in the groove 5 is instantly spread over a wide area on the inner peripheral surface of the bearing portion 2. Can be supplied to.

  An automobile or the like that frequently stops and starts the internal combustion engine is in a condition where the lubrication state between the rocker arm 1 and the rocker shaft 6 is not necessarily good, and according to the present invention, Even in the case of automobiles and the like, a good lubrication state can be maintained. Along with this, it is not necessary to use an expensive material for the sliding portion, and the cost can be reduced. In addition, the good lubrication state reduces the friction of the sliding portion at the time of low temperature start, so that the low temperature startability of the internal combustion engine is also improved.

  When the groove width W of the groove 5 is, for example, 5% to 25% of the inner diameter D of the bearing portion 2 and the groove length L1 is 30% or more of the axial length L2 of the bearing portion 2, a predetermined amount of oil It becomes easy to supply oil immediately in a wide area. The depth of the groove is appropriately determined as necessary, and is, for example, about 5% to 25% of the inner diameter D.

  The axial cross-sectional shape of the groove 5 can be a shape in which the depth is changed stepwise, for example, as shown in FIG. In particular, it is possible to adopt a shape that deepens the middle and shallows both ends. According to these shapes, a large amount of oil can be stored in a deep part, and the stored oil can be supplied more quickly to a wider range of the inner peripheral surface of the bearing portion 2.

  The number and formation positions of the oil supply passages 7 are not limited to those shown in the embodiment and can be determined as appropriate. The oil supply passages 7 penetrate the inside of the rocker arm 1 substantially horizontally and are opened on the inner peripheral surface of the bearing portion 2. If the position to be formed is formed at a position different from the groove 5, the oil can be easily supplied without being excessive or insufficient.

  Further, without providing the oil supply path 7, for example, the oil supplied from the outside to the hollow portion of the rocker shaft 6 is caused to flow from the hollow portion to the outer peripheral surface through the communication hole provided in the peripheral wall of the rocker shaft 6. You may make it accumulate in the groove | channel 5.

  In the embodiment, the bearing portion 2 is a cylindrical through-hole integrated with the rocker arm 1. However, the bearing portion 2 may have a structure having a rocker bush on the inner peripheral surface. When the rocker bush is provided, a groove 5 extending in the axial direction of the rocker shaft 6 is provided at a position on the inner peripheral surface of the rocker bush at the bottom when the internal combustion engine is stopped, thereby ensuring a good lubrication state. can do.

It is a front view which illustrates the lubrication structure of the rocker arm of this invention. It is AA sectional drawing of FIG. It is BB sectional drawing of FIG. It is CC sectional drawing of FIG. It is an axial direction sectional view showing another example of a groove formed in a bearing part. It is an axial direction sectional view showing another example of a groove formed in a bearing part. It is a longitudinal cross-sectional view which illustrates the outline | summary of a valve operating chamber inside.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rocker arm 2 Bearing part 3 Valve contact part 4 Cam contact part 5 Groove 6 Rocker shaft 7 Oil supply path 7a, 7b Open end 8 Valve 9 Cam 10 Valve chamber

Claims (3)

  In a lubricating structure of a rocker arm of an internal combustion engine that has a bearing portion and is pivotally supported by a rocker shaft that passes through the bearing portion so that the longitudinal end portion thereof is swingable, when the internal combustion engine on the inner peripheral surface of the bearing portion is stopped A lubricating structure for a rocker arm, characterized in that a groove extending in the axial direction of the rocker shaft is provided at a position to be a bottom.   An oil supply path that penetrates the inside of the rocker arm substantially horizontally is provided, one end of the oil supply path is open to the outside of the rocker arm, and the other end is the groove on the inner peripheral surface of the bearing portion of the rocker arm. The lubricating structure for a rocker arm according to claim 1, wherein the lubricating structure is opened at another position.   The rocker according to claim 1 or 2, wherein a groove width of the groove is 5% or more and 25% or less of an inner diameter of the bearing portion, and a groove length of the groove is 30% or more of an axial length of the bearing portion. Arm lubrication structure.

Images