JP2016156293A - Lubrication structure of valve train - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lubrication structure of a valve train capable of reducing lubricant supply amount from a lubricant supply path to a locker arm, and supplying the sufficient amount of lubricant for an abutting portion with a locker arm valve.SOLUTION: A driving locker arm 13a has: a recessed portion 35 opening toward an intake cam shaft 16a; a roller 34 received in the recessed portion 35 and abutting on a low-speed cam 15a; a first lubricant path 36 opening toward a locker arm shaft 17a and communicating with a bottom portion 35a of the recessed portion 35; and a second lubricant path 37 communicating with the bottom portion 35a of the recessed portion 35 and opening toward an abutting portion with an intake valve 11. While the driving locker arm 13a abuts on a base circle of the low-speed cam 15a, a lubricant supply path 21 and the first lubricant path 36 are shut off. When the driving locker arm 13a is driven by the low-speed cam 15a, the lubricant supply path 21 and the first lubricant path 36 are communicated, and the bottom portion 35a of the recessed portion 35 includes a linear oil path communicating the first lubricant path 36 and the second lubricant path 37.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a lubrication structure for a valve operating mechanism including a switching mechanism that selectively connects or disconnects a first rocker arm and a second rocker arm.

  As a valve operating mechanism that opens and closes an intake / exhaust valve of an engine, a variable valve timing mechanism that changes the opening / closing timing of the valve in accordance with the operating state of the engine is known. In the variable valve timing mechanism, a plurality of rocker arms are juxtaposed, and the connected and unconnected states between adjacent rocker arms are switched by a switching mechanism that drives a connecting pin.

  In an engine equipped with such a variable valve timing mechanism, the number of sliding parts to be lubricated increases, so the amount of lubricating oil supplied increases. In particular, when the switching mechanism uses the lubricating oil as the working oil in order to drive the connecting pin, the supply amount of the lubricating oil is further increased, and the oil pump needs to be enlarged. Accordingly, the present applicant has provided a recess for receiving a roller (cam follower) in the rocker arm on the side in contact with the valve so that the lubricating oil can be supplied to an appropriate place with the minimum necessary amount of oil, and the rocker arm shaft. Provided with a first lubricating oil passage that communicates with the bottom of the concave portion and a second lubricating oil passage that communicates with the bottom of the concave portion and opens toward the contact portion with the valve. Proposed a lubricating oil structure (Patent Document 1).

Japanese Patent No. 5118179

  However, in the lubricating oil structure described above, the outer peripheral surface of the roller rotates from the second lubricating oil passage side toward the first lubricating oil passage side in the concave portion, and the lubricating oil in the concave portion attached to the outer peripheral surface of the roller is caused by the roller. Since it winds up, it becomes difficult to supply lubricating oil to a 2nd lubricating oil path. For this reason, in order to supply a sufficient amount of lubricating oil to the second lubricating oil passage, it has been necessary to increase the hydraulic pressure to some extent or increase the amount of lubricating oil supplied to some extent. In other words, there was room for further improvement in reducing the amount of oil supplied.

  In view of such a background, the present invention can reduce the amount of lubricating oil supplied from the lubricating oil supply path to the rocker arm, and can supply a sufficient amount of lubricating oil to a contact portion of the rocker arm with the valve. It is an object to provide a lubrication structure for a mechanism.

  In order to solve such a problem, in the present invention, one end (31) is pivotally supported by the rocker arm shaft (17a) and the other end (32) is in contact with the valve (11). And a rocker arm (13a) whose middle part contacts the cam (15a) of the cam shaft (16a), and a lubricating oil supply passage (21) formed on the rocker arm shaft and supplying lubricating oil to the rocker arm, A concave portion (35) that opens toward the cam shaft and a roller (34) that is received in the concave portion and abuts against the cam are provided in an intermediate portion of the rocker arm, and the rocker arm is attached to the rocker arm shaft. The first lubricating oil passage (36) that opens toward the bottom and communicates with the bottom (35a) of the recess, and the second lubricating oil that communicates with the bottom of the recess and opens toward the contact portion with the valve With road (37) When the rocker arm is in contact with the base circle of the cam, the lubricating oil supply path and the first lubricating oil path are cut off, and when the rocker arm is driven by the cam, the lubricating oil supply path and the An oil passage structure of a valve mechanism (10) communicating with a first lubricating oil passage, wherein a bottom (35a) of the recess communicates with the first lubricating oil passage and the second lubricating oil passage. It is set as the structure containing this oil path.

  Here, including a straight oil passage means forming an oil passage space in which the opening of the first lubricating oil passage and the opening of the second lubricating oil passage can be connected in a straight line without being blocked by a roller or the like. Means.

  According to this configuration, since the lubricating oil supply path and the first lubricating oil path are cut off when the rocker arm is in contact with the base circle of the cam, the lubricating oil supplied to the rocker arm from the lubricating oil supply path is cut off. The amount is reduced. Further, since the flow of the lubricating oil stored in the bottom of the recess from the first lubricating oil path to the second lubricating oil path is prevented from being inhibited by the rotation of the roller, the second lubricating oil path from the bottom of the recess is suppressed. A sufficient amount of lubricating oil is supplied to the contact portion of the rocker arm with the valve.

  In the above invention, the second lubricating oil passage (37) is located on a virtual extension line (36X) of the central axis of the first lubricating oil passage (36), and the concave portion (35) is the first lubricating oil passage (36). A linear shape having a bottom surface (35b) parallel to a virtual extension line of the central axis of the lubricating oil passage, and a bottom portion (35a) of the recess cooperating with the first lubricating oil passage and facing the second lubricating oil passage It is good to make the structure which makes this oil path.

  According to this configuration, since the bottom of the recess and the first lubricating oil passage form a straight oil passage, the lubricating oil ejected from the first lubricating oil passage reaches the second lubricating oil passage through the recess. Therefore, the lubricating oil is more reliably supplied from the second lubricating oil passage to the contact portion with the valve of the rocker arm.

  In the above invention, the roller (34) may be provided at a position not intersecting with a virtual extension line (36X) of the central axis of the first lubricating oil passage (36).

  According to this configuration, the rolling-up of the lubricating oil stored in the bottom of the concave portion is suppressed and the lubricating oil is easily supplied to the second lubricating oil passage, so the amount of oil supplied to the concave portion is reduced. However, a sufficient amount of lubricating oil is supplied to the contact portion of the rocker arm with the valve.

  In the above invention, the gap (G) at the portion where the bottom surface of the recess and the roller are closest may be larger than the diameter (D1) of the first lubricating oil passage (36).

  According to this configuration, the cross-sectional area of the oil passage (space forming the oil passage) formed at the bottom of the concave portion is increased, and the amount of lubricating oil that is not pulled back to the first lubricating oil passage side by the roller increases. It becomes easy to be supplied to the second lubricating oil passage.

  In the above invention, the side surface (36d) on the other end (32) side that defines the recess (35) of the rocker arm (13a) is directed toward the opening end of the second lubricating oil passage. It is good to set it as the structure which is an arc-shaped surface which narrows the width | variety of a recessed part.

  According to this configuration, the lubricating oil wound up by the rotation of the roller and adhering to the wall surface of the recess located on the other end side of the rocker arm is guided to the second lubricating oil passage along the arcuate surface. Even if the amount of lubricating oil is reduced, sufficient lubrication can be obtained. As a result, it is possible to extend the life of the valve mechanism, reduce the amount of lubricating oil, reduce the size of the oil pump, and extend the life.

  In the above invention, the rocker arm (15a) is disposed adjacently, and one end (41) is pivotally supported by the rocker arm shaft (17a) and the other end (42) is lost motion. An auxiliary rocker arm (13b) that contacts the spring (50); and a switching mechanism (10a) that selectively connects or disconnects the rocker arm and the auxiliary rocker arm by supplying hydraulic oil. The oil supply path (21) may serve as the hydraulic oil supply oil path of the switching mechanism.

  According to this configuration, the number of oil passages formed on the rocker arm shaft is reduced, and the configuration of the rocker arm shaft is simplified. In addition, the hydraulic circuit is simplified by reducing the number of oil passages. Note that the bottom of the recess forms a linear oil path that connects the first lubricating oil path and the second lubricating oil path, and the lubricating oil easily accumulates in the recess, so the switching mechanism is not operating. During the period, the abutting portion with the roller and the valve is lubricated by the lubricating oil stored in the recess.

  Thus, according to the present invention, the amount of lubricating oil supplied from the lubricating oil supply path to the rocker arm can be reduced, and a sufficient amount of lubricating oil can be supplied to the abutting portion of the rocker arm with the valve. A lubrication structure can be provided.

Schematic side view of an engine to which the present invention is applied Front view of main part seen from the arrow II line in FIG. Side view of valve mechanism Explanatory drawing of variable valve timing mechanism (A) Main part side sectional view showing the cam base circle contact state of the rocker arm, (b) Main part side sectional view showing a state where the rocker arm is driven and swung by the cam. (A) Main part side sectional view showing the cam base circle contact state of the auxiliary rocker arm, (b) Main part side sectional view showing a state where the auxiliary rocker arm is driven and swung by the cam. Enlarged sectional view of the drive rocker arm VIII-VIII sectional view in FIG.

  Hereinafter, an embodiment in which the present invention is applied to an automobile engine 1 will be described in detail with reference to the drawings.

  As shown in FIGS. 1 and 2, the engine 1 includes a cylinder block 2 that defines a plurality of cylinders (not shown), a cylinder head 3 that is joined to the top of the cylinder block 2, and a cylinder block 2. A lower block 4 which is joined to the lower part and forms a crankcase in cooperation with the cylinder block 2 is provided as an engine body. The engine 1 includes a head cover 5 that is joined to the upper part of the cylinder head 3 and defines a valve operating chamber in cooperation with the cylinder head 3, and an oil pan 6 that is joined to the lower part of the lower block 4. Yes.

  In FIG. 1, the engine 1 is shown as an in-line four cylinder, but the cylinder row and the number of cylinders of the engine 1 to be applied may be arbitrary. 1 to 3, the engine 1 is shown with the cylinder axis extending along the vertical direction, but the direction of the engine 1 mounted on the automobile is not limited to this.

  A crankshaft 7 extending along the cylinder row direction is accommodated in the crankcase. The crankshaft 7 is rotatably supported by the engine body and protrudes from the engine body. As shown in FIG. 2, a timing chain 8 a constituting the timing train mechanism 8 is provided on one end side in the crankshaft direction of the engine body. The timing train mechanism 8 is covered with a chain case 9 joined to the side surface of the engine body.

  The timing chain 8a includes a pulley 8b fixed to an axial end portion (a portion protruding from the engine body) of the crankshaft 7, a pulley fixed to a cam shaft (see FIG. 3) received in the head cover 5. It is wound over. A chain guide 8c for guiding the timing chain 8a and a tensioner 8d for applying a predetermined tension to the timing chain 8a are provided in the engine body.

  As shown in FIG. 3, a combustion chamber recess 3a is formed on the lower surface of the cylinder head 3 at a position corresponding to the cylinder. The cylinder head 3 has an intake passage 3b that opens to one side along the cylinder row direction and opens to the combustion chamber recess 3a, and an exhaust that opens to the combustion chamber recess 3a and opens to the other side along the cylinder row direction. A passage 3c is formed. In the present embodiment, two intake passages 3b and two exhaust passages 3c are formed for each cylinder. In the cylinder head 3, a plurality (eight in this embodiment) of intake valves 11 that open and close the intake passage 3b and a plurality (eight in this embodiment) of exhaust valves 12 that open and close the exhaust passage 3c are slidable. Is provided. A valve operating mechanism 10 that opens and closes the intake valve 11 and the exhaust valve 12 is provided in the valve operating chamber.

  The valve operating mechanism 10 is provided between the intake cam shaft 16a and the exhaust cam shaft 16b, which are arranged in parallel with the crankshaft 7, and between the intake cam shaft 16a and the intake valve 11, and is driven by the intake cam shaft 16a to be operated by the intake valve. 11 includes a rocker arm 13 that opens and closes 11, a rocker arm 14 that is provided between the exhaust cam shaft 16 b and the exhaust valve 12, and that drives the exhaust cam shaft 16 b to open and close the exhaust valve 12. The intake camshaft 16a and the exhaust camshaft 16b are rotationally driven in synchronization with the crankshaft 7 by the timing train mechanism 8 at half the rotational speed of the crankshaft 7. Further, the valve mechanism 10 of the present embodiment has a variable valve timing mechanism 10a as a switching mechanism that selectively connects or disconnects a plurality of rocker arms 13 arranged in parallel.

  Hereinafter, the structure of the valve mechanism 10 and the variable valve timing mechanism 10a will be described with reference to FIGS.

  The variable valve timing mechanism 10a of the present embodiment changes the lift amount and the valve opening timing by dividing the intake valve 11 into two stages (low speed and high speed). The intake camshaft 16a is disposed between two low-speed cams 15a and 15a for driving the intake valves 11 provided for each cylinder, and the low-speed cams 15a and 15a, and has a cam profile different from that of the low-speed cam 15a. One high-speed cam 15b is integrally provided. In addition, 15c (FIG. 3) which has one kind of cam profile with respect to the exhaust valve 12 is integrally provided in the exhaust cam shaft 16b.

  One end (right end in the figure) of the rocker arm 13 for the intake valve is pivotally supported by the rocker arm shaft 17a, and is cam-driven by the corresponding low-speed cam 15a and the corresponding intake valve 11 as shown in FIG. Two drive rocker arms 13a, 13a that are in contact with the axial ends of the drive rocker arm, and an auxiliary rocker arm 13b that is disposed adjacent to and between these drive rocker arms 13a, 13a and that is in contact with the high speed cam 15b and is cam driven. It is configured.

  Each of the drive rocker arms 13a and 13a is provided with bottomed cylindrical holes 18a and 18a that are open in opposite directions and have the same hole diameter. Through holes 18b having the same diameter as the bottomed cylindrical holes 18a, 18a are provided. The bottomed cylindrical holes 18a and 18a and the through holes 18b are arranged coaxially with each other in a state where the rocker arms 13 (13a to 13c) are not driven.

  On the other hand (left end in FIG. 4), the bottomed cylindrical hole 18a of the drive rocker arm 13a and the through-hole 18b of the auxiliary rocker arm 13b have connecting pins 19a, 19b of the same length as the axial direction of the respective holes 18 in the axial direction. Is slidably provided. In the bottomed cylindrical hole 18a of the other drive rocker arm 13a (the right end in FIG. 4), a short shaft pin 19c shorter than the axial length of the bottomed cylindrical hole 18a is provided slidably in the axial direction. The short shaft pin 19c is always urged toward the connecting pins 19a and 19b by the compression coil spring 20. Each of these pins 19 (19a to 19c) is formed to have the same diameter.

  Further, as shown in FIG. 3, the rocker arm shaft 17a is provided with one lubricating oil supply passage 21 extending in the axial direction. The lubricating oil supply path 21 supplies lubricating oil to the rocker arm 13 and communicates with the bottom surface of the bottomed cylindrical hole 18a on the side (left end) in which the connecting pin 19a is accommodated, and the operation of the variable valve timing mechanism 10a. Also serves as an oil supply path. The details of the lubricating oil path for the rocker arm 13 will be described later.

  In a state where the oil pressure from the lubricating oil supply passage 21 is not supplied (or a state where the oil pressure is low), the short shaft pin 19c is spring-biased toward the connection pins 19a and 19b by the compression coil spring 20, and the left connection pin 19a is It contacts the bottom surface of the bottomed cylindrical hole 18a. In this state, each pin 19 (19a to 19c) is buried in each corresponding hole 18 (18a, 18b, 18a), and each rocker arm 13 can swing independently.

  On the other hand, the operating oil pressure is selectively supplied to the bottom surface portion of the left bottomed cylindrical hole 18a through the lubricating oil supply passage 21, so that the connecting pins 19a and 19b are biased by the compression coil spring 20. Against the short shaft pin 19c side. As a result, a part of the left connecting pin 19a enters the through hole 18b to connect the left end drive rocker arm 13a and the auxiliary rocker arm 13b, and a part of the right connecting pin 19a enters the bottomed cylindrical hole 18a. Thus, the auxiliary rocker arm 13b is connected to the other (right side) drive rocker arm 13a.

  Each of these states implements the two stages described above. The hydraulic circuit may have a simple configuration capable of switching between an on state in which the operating oil pressure is supplied and an off state in which the operating oil pressure is not supplied, and is provided in an oil passage communicating with the oil pump or the main gallery, And a switching valve. The hydraulic circuit is configured to supply an oil pressure lower than the operating oil pressure even when the variable valve timing mechanism 10a is in an OFF state so that the lubricating oil is constantly supplied to the rocker arm 13.

  Next, the outline of the shape and lubricating structure of each rocker arm 13 will be described.

  As shown in FIG. 5, the lubricating oil supply passage 21 is formed at the center of the rocker arm shaft 17a as described above. A circumferential wall (rocker arm shaft 17a) that defines the lubricating oil supply passage 21 is provided with a radial oil passage 21a that opens to the outer peripheral surface to supply the lubricating oil to the sliding portion with the drive rocker arm 13a (of the lubricating oil supply passage 21). Part) is formed.

  The drive rocker arm 13a extends from a base end portion 31 pivotally supported by the rocker arm shaft 17a to a position where it can face the axial end of the intake valve 11. The extension end portion 32 of the drive rocker arm 13a An adjusting screw 33 that abuts the axial end is provided. A roller 34 serving as a cam follower that is in rolling contact with the low-speed cam 15a is rotatably supported at an intermediate portion of the drive rocker arm 13a. In addition, a recess 35 is provided at the intermediate portion of the drive rocker arm 13a so as to open toward the cam shaft. The recess 35 receives almost the entire portion excluding the portion that contacts the low-speed cam 15a of the roller 34.

  The base end portion 31 of the drive rocker arm 13a has a cylindrical shape, and the inner peripheral surface thereof is in sliding contact with the outer peripheral surface of the rocker arm shaft 17a. A first lubricating oil passage 36 is formed in the proximal end portion 31 of the drive rocker arm 13a so as to open in the inner peripheral surface toward the rocker arm shaft 17a and to penetrate in the radial direction so as to communicate with the bottom portion 35a of the recess 35. . In addition, the bottom part 35a means the space part of the recessed part 35 on the side opposite to opening.

  As shown in FIG. 5A, the first lubricating oil passage 36 is a position where the roller 34 does not communicate with the radial oil passage 21a in a state where the roller 34 abuts against the base circle of the low-speed cam 15a. As shown in FIG. 4, the roller 34 abuts against the cam crest of the low speed cam 15a, and the drive rocker arm 13a is formed in a communicating position with the radial oil passage 21a when being driven by the low speed cam 15a. In the present embodiment, the first lubricating oil passage 36 is communicated with the radial oil passage 21a only within a predetermined crank angle range centering on the swing angle of the drive rocker arm 13a, that is, the crank angle at which the valve lift amount is maximum. The position and the cross-sectional dimension are set. Thereby, the supply amount of the lubricating oil is reduced.

  The extended end portion 32 of the drive rocker arm 13 a communicates with the bottom portion 35 a of the recess 35 and opens toward the abutting portion between the adjusting screw 33 and the end of the intake valve 11 in the axial direction. Is provided.

  According to the drive rocker arm 13a formed in this way, the low speed cam 15a rotates as shown by the arrow A in FIG. 5A and is pushed by the cam crest of the low speed cam 15a shown in FIG. 5B. When the oscillates, the radial oil passage 21a and the first lubricating oil passage 36 communicate with each other, and the lubricating oil is sent from the lubricating oil supply passage 21 to the first lubricating oil passage 36 as shown by the arrows in the figure. The lubricating oil supplied from the first lubricating oil passage 36 to the bottom 35 a of the recess 35 is supplied to the contact portion between the adjustment screw 33 and the intake valve 11 via the second lubricating oil passage 37. Further, the lubricating oil stored in the concave portion 35 or the lubricating oil scattered in the concave portion 35 adheres to the outer peripheral surface of the roller 34, and the roller 34 rotates in the arrow B direction by the rotation of the low-speed cam 15a in the arrow A direction. Is supplied to the contact portion with the low-speed cam 15a. Since the first lubricating oil passage 36 communicates with the bottom 35a of the recess 35, it also has a function of flowing out contamination and the like accumulated in the recess 35.

  As shown in FIG. 6, the lubricating oil is supplied to the sliding portion with the auxiliary rocker arm 13b on the peripheral wall (rocker arm shaft 17a) that defines the lubricating oil supply passage 21 even at the position corresponding to the auxiliary rocker arm 13b. Thus, a radial oil passage 21b that opens to the outer peripheral surface is provided.

  The auxiliary rocker arm 13b extends from the base end portion 41 supported by the rocker arm shaft 17a to a position corresponding to the high speed cam 15b. The extension part 42 of the auxiliary rocker arm 13b is provided with a concave part 45 for receiving the roller 44 in the same manner as described above, and a branch part 43 that abuts against the lost motion spring 50. The lost motion spring 50 is for suppressing the flapping of the auxiliary rocker arm 13b where the spring biasing force in the return direction by the intake valve 11 does not act.

  Further, the base end portion 41 of the auxiliary rocker arm 13b has a cylindrical shape, and the inner peripheral surface thereof is in sliding contact with the outer peripheral surface of the rocker arm shaft 17a. On the inner peripheral surface of the base end portion 41 of the auxiliary rocker arm 13b, an arc groove 46a is provided over a predetermined angular range. As shown in FIG. 6A, one end in the circumferential direction of the circular arc groove 46a is disposed at a position where the roller 44 does not communicate with the radial oil passage 21b when the roller 44 is in contact with the base circle of the high-speed cam 15b. The other end in the circumferential direction of the arc groove 46a communicates with a discharge passage 46b that opens toward the contact portion between the roller 44 and the high-speed cam 15b. The circular groove 46a and the discharge passage 46b constitute a third lubricating oil passage 46 that supplies the lubricating oil supplied from the lubricating oil supply passage 21 to the contact portion between the roller 44 and the high-speed cam 15b.

  According to the auxiliary rocker arm 13b formed in this way, the high-speed cam 15b rotates as shown by the arrow A in FIG. 6 (a) and is pushed by the cam crest of the high-speed cam 15b shown in FIG. 6 (b). In this state, the radial oil passage 21b communicates with one end in the circumferential direction of the circular arc groove 46a, and the lubricating oil is fed from the lubricating oil supply passage 21 to the circular arc groove 46a as shown by the arrow in the figure. As a result, the lubricating oil in the circular arc groove 46a is sent out from the discharge passage 46b toward the contact portion between the roller 44 and the high speed cam 15b as shown by the arrow C in the figure, and the contact between the roller 44 and the high speed cam 15b. Lubricating oil is satisfactorily supplied to the contact portion. Note that the lubricant oil that adheres to the outer peripheral surface of the roller 44 and is supplied to the contact portion with the high-speed cam 15b is transmitted to the contact portion with the lost motion spring 50 through the branch portion 43 as indicated by an arrow D. Supplied after falling.

  In this manner, in the drive rocker arm 13a shown in FIG. 5, since a large load is applied to the contact portion with the intake valve 11, the contact portion between the adjustment screw 33 and the end of the intake valve 11 in the axial direction is applied. On the other hand, the lubricating oil may be mainly supplied. With the above structure, the lubricating oil stored in the recess 35 can be positively supplied through the second lubricating oil passage 37. On the other hand, in the auxiliary rocker arm 13b shown in FIG. 6, since the high-speed cam 15b is a large cam (large displacement) among the cams, a large load is applied from the high-speed cam 15b to the contact portion with the high-speed cam 15b. The lubricating oil may be mainly supplied to the contact portion between the roller 44 and the high-speed cam 15b. With the above structure, the lubricating oil sent to the arc groove 46a is positively supplied via the discharge passage 46b. Can do.

  Next, details of the shape and lubrication structure of the drive rocker arm 13a according to the present invention will be described.

  As shown in FIG. 7, the recess 35 formed in the drive rocker arm 13a is not shaped along the outer peripheral surface of the roller 34, but is shaped like a bathtub with a bottom 35b having a flat bottom 35a. The side surface 36c on the base end portion 31 side and the side surface 36d on the extended end portion 32 side of the recess 35 are linear in the same cross section, and these side surfaces 36c, 36d and the bottom surface 36b are formed by curved surfaces 36e, 36e. It is connected. Then, the side surface 36d and the curved surface 36e on the extended end portion 32 side of the concave portion 35 are arcuate to narrow the width of the concave portion 35 toward the opening end of the second lubricating oil passage 37, as shown in FIG. It is a surface.

  As shown in FIG. 7, the first lubricating oil passage 36 is formed by drilling from the base end side of the drive rocker arm 13a so as to open to the curved surface 36e on the base end portion 31 side. Therefore, the first lubricating oil passage 36 has a circular cross section, and the first lubricating oil passage 36 is formed on the side opposite to the first lubricating oil passage 36 with respect to the rocker arm shaft 17a in the base end portion 31. The processed hole 38 is left. The second lubricating oil passage 37 is formed by drilling so as to open to the curved surface 36e on the extended end portion 32 side. Therefore, the second lubricating oil passage 37 has a circular cross section.

  Further, the first lubricating oil passage 36 is formed such that a virtual extension line 36 </ b> X of the central axis thereof is parallel to the bottom surface 36 b of the recess 35. The second lubricating oil passage 37 is disposed at a position that opens to the curved surface 36e on the virtual extension line 36X of the central axis of the first lubricating oil passage 36. Further, the recess 35 is formed to a depth such that the gap G where the bottom surface 36 b and the roller 34 are closest is equal to or larger than the diameter D 1 of the first lubricating oil passage 36. Further, the roller 34 is disposed at a position not intersecting with the virtual extension line 36 </ b> X of the central axis of the first lubricating oil path 36. Therefore, the bottom 35 a of the recess 35 includes a linear oil passage that communicates the first lubricating oil passage 36 and the second lubricating oil passage 37.

  In this specification, including or forming a linear oil passage means that the opening of the first lubricating oil passage 36 and the opening of the second lubricating oil passage 37 are connected by a straight line without being blocked by the roller 34 or the like. It means to form an oil passage space that can. That is, in this embodiment, the recess 35 provides an oil passage space that can connect the center of the opening of the first lubricating oil passage 36 and the center of the opening of the second lubricating oil passage 37 with a straight line without being blocked by the roller 34. Although formed, for example, the end of the opening of the first lubricating oil passage 36 near the bottom surface 36b and the end of the opening of the second lubricating oil passage 37 near the bottom surface 36b are not blocked by the roller 34 or the like. It can be said that a straight oil passage is included or formed if an oil passage space that can be connected with a straight line is formed.

  In this way, the bottom 35a of the recess 35 forms a linear oil path that connects the first lubricating oil path 36 and the second lubricating oil path 37, so that the lubricating oil stored in the bottom 35a of the recess 35 can be It is suppressed that the flow from the first lubricating oil passage 36 to the second lubricating oil passage 37 is hindered by the rotation of the roller 34. Therefore, a sufficient amount of lubricating oil is supplied from the bottom 35 a of the recess 35 through the second lubricating oil passage 37 to the contact portion of the drive rocker arm 13 a with the intake valve 11.

  In the present embodiment, the second lubricating oil passage 37 is positioned on the virtual extension line 36X of the central axis of the first lubricating oil path 36, and the recess 35 is located on the virtual extension line 36X of the central axis of the first lubricating oil path 36. It has a parallel bottom surface 36b. As a result, the bottom 35 a of the recess 35 cooperates with the first lubricating oil passage 36 to form a straight oil passage facing the second lubricating oil passage 37. Therefore, the lubricating oil ejected from the first lubricating oil passage 36 easily reaches the second lubricating oil passage 37 through the recess 35, and comes into contact with the intake valve 11 of the drive rocker arm 13a from the second lubricating oil passage 37. Lubricating oil is more reliably supplied to the part.

  Further, since the roller 34 is provided at a position that does not intersect with the virtual extension line 36X of the central axis of the first lubricating oil passage 36, the rolling-up of the lubricating oil roller 34 stored in the bottom 35a of the recess 35 is suppressed. . Accordingly, since the lubricating oil is easily supplied to the second lubricating oil passage 37, a sufficient amount of lubricating oil even if the amount of oil supplied to the recess 35 is reduced is a contact portion with the intake valve 11 of the drive rocker arm 13a. To be supplied.

  Further, since the gap G where the bottom surface 36b of the recess 35 and the roller 34 are closest to each other is equal to or larger than the diameter D1 of the first lubricating oil passage 36, an oil passage (forming an oil passage) formed in the bottom 35a of the recess 35 is formed. The cross-sectional area of the (space) increases, and the amount of lubricating oil that is not drawn back to the first lubricating oil passage 36 by the roller 34 increases. This also facilitates the supply of the lubricating oil to the second lubricating oil passage 37.

  Further, as shown in FIG. 8, the side surface 36 d and the curved surface 36 e on the extended end portion 32 side that define the concave portion 35 of the drive rocker arm 13 a are formed toward the opening end of the second lubricating oil passage 37. Since it has an arcuate surface that narrows the width, the lubricating oil that is wound up by the rotation of the roller 34 and adheres to the wall surface of the recess 35 located on the other end side of the drive rocker arm 13a travels along the arcuate surface. Guided to oil passage 37. Therefore, sufficient lubrication can be obtained even if the amount of lubricating oil from the rocker arm shaft 17a is reduced, thereby extending the life of the valve operating mechanism 10, reducing the amount of lubricating oil, and reducing the size and extending the life of the oil pump. It is done.

  Further, in this embodiment, as shown in FIG. 6, the base end portion 41 is pivotally supported by the rocker arm shaft 17a and the auxiliary rocker arm 13b whose extension portion 42 abuts on the lost motion spring 50 is driven. A variable valve timing mechanism 10a is provided adjacent to the rocker arm 13a and selectively connects or disconnects the drive rocker arm 13a and the auxiliary rocker arm 13b shown in FIG. 4 by supplying hydraulic oil. Since the supply amount of the lubricating oil is small as described above, the lubricating oil supply path 21 can also serve as the hydraulic oil supply oil path of the variable valve timing mechanism 10a. This reduces the number of oil passages formed in the rocker arm shaft 17a, simplifies the configuration of the rocker arm shaft 17a, and eliminates the need for a separate member or partition wall for partitioning the oil passage. Cost reduction is possible. In addition, the hydraulic circuit is simplified by reducing the number of oil passages. In addition, since the supply amount as lubricating oil is small as described above, the influence on the operation and responsiveness of the variable valve timing mechanism 10a is small.

  The rotation direction of the roller 34 may be reverse to that illustrated in the above embodiment. When the rotation of the roller 34 is reverse, the amount of lubricating oil supplied to the second lubricating oil passage 37 is further increased. Can be increased. In the above embodiment, the rocker arm structure on the intake valve 11 side is shown, but the present invention can be similarly applied to the exhaust valve 12 side.

  Although the description of the specific embodiment is finished as described above, the present invention is not limited to the above embodiment and can be widely modified. For example, in the above-described embodiment, the present invention is applied to the automobile engine 1 as an example. However, the present invention can be widely applied to railway vehicles, aircrafts, and the like. In addition, the specific configuration, arrangement, quantity, and angle of each member and part can be changed as long as they do not depart from the spirit of the present invention. On the other hand, all the components of the lubrication structure of the valve operating mechanism 10 shown in the above embodiment are not necessarily essential, and can be selected as appropriate.

1 Engine 10 Valve mechanism 10a Variable valve timing mechanism (switching mechanism)
11 Intake Valve 13a Drive Rocker Arm 13b Auxiliary Rocker Arm 15a Low Speed Cam 16a Intake Cam Shaft 17a Rocker Arm Shaft 21 Lubricating Oil Supply Path 31 Base End (One End)
32 Extension end (other end)
34 Roller 35 Recess 35a Bottom 35b Bottom 35d Side (the other side)
36 First lubricating oil path 36X Virtual extension line of central axis of first lubricating oil path 37 Second lubricating oil path 41 Base end (one end)
42 Extension (other end)
50 Lost motion spring D1 Diameter of first lubricating oil passage G Gap

Claims (6)

A rocker arm whose one end is pivotally supported by a rocker arm shaft and whose other end is in contact with the valve and whose intermediate portion is in contact with the cam of the camshaft;
A lubricating oil supply passage formed on the rocker arm shaft and supplying lubricating oil to the rocker arm;
A concave portion that opens toward the cam shaft and a roller that is received in the concave portion and contacts the cam are provided in an intermediate portion of the rocker arm.
The rocker arm opens toward the rocker arm shaft and communicates with the bottom of the recess, and communicates with the bottom of the recess and opens toward the contact portion with the valve. A lubricating oil passage,
When the rocker arm is in contact with the base circle of the cam, the lubricating oil supply path and the first lubricating oil path are cut off, and when the rocker arm is driven by the cam, the lubricating oil supply path and the An oil passage structure of a valve mechanism that communicates with the first lubricating oil passage,
An oil passage structure of a valve mechanism, wherein a bottom portion of the concave portion forms a linear oil passage communicating the first lubricating oil passage and the second lubricating oil passage. The second lubricating oil passage is located on a virtual extension line of the central axis of the first lubricating oil passage;
The concave portion has a bottom surface parallel to a virtual extension line of the central axis of the first lubricating oil passage;
2. The lubricating structure for a valve operating mechanism according to claim 1, wherein a bottom portion of the concave portion forms a linear oil passage facing the second lubricating oil passage in cooperation with the first lubricating oil passage.   The lubrication structure for a valve operating mechanism according to claim 1 or 2, wherein the roller is provided at a position not intersecting with a virtual extension line of a central axis of the first lubricating oil passage.   The lubrication of the valve operating mechanism according to any one of claims 1 to 3, wherein a gap between a portion where the bottom surface of the recess and the roller are closest to each other is equal to or larger than a diameter of the first lubricating oil passage. Construction.   The side surface of the rocker arm that defines the concave portion on the other end side is an arc-shaped surface that narrows the width of the concave portion toward the opening end of the second lubricating oil passage. The lubricating structure of the valve operating mechanism according to any one of claims 4 to 5. An auxiliary rocker arm disposed adjacent to the rocker arm, one end of which is pivotally supported by the rocker arm shaft and the other end abutting against the lost motion spring;
A switching mechanism for selectively connecting or disconnecting the rocker arm and the auxiliary rocker arm by supplying hydraulic oil;
The oil passage structure of the valve operating mechanism according to any one of claims 1 to 5, wherein the lubricating oil supply passage also serves as a hydraulic oil supply oil passage for the switching mechanism.

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