JP2007113523A - Variable valve operating mechanism for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To facilitate handling of a variable valve operating mechanism for an internal combustion engine at a time of transportation of an energizing mechanism and at a time of installation to the internal combustion engine. <P>SOLUTION: The variable valve operating mechanism 30 includes a rocker shaft 31, a control shaft 32 and a valve lift mechanism 34, and the valve lift mechanism 34 includes a cam struck member 41, valve striking members 42A, 42B and a slider gear 43. Moreover, an energizing mechanism 50 for making the cam struck member 41 abut on the cam 13a is included. The energizing mechanism 50 includes a spring 51 energizing the cam struck member 41 to a cam 13a side and a holder 52 storing the spring 51, and the spring 51 is inseparably attached to the holder 52. Consequently, since the spring 51 does not come off the holder 52, handling of the energizing mechanism 50 is facilitated. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a variable valve mechanism that can change the operating characteristics of an intake valve or an exhaust valve of an internal combustion engine.

  2. Description of the Related Art There is known a variable valve mechanism that varies operating characteristics such as valve lift and operating angle of intake valves and exhaust valves in accordance with the operating state of an internal combustion engine (see, for example, Patent Document 1).

  This variable valve mechanism has an intermediate drive mechanism arranged between the cam and the valve, and this intermediate drive mechanism is interlocked with the axial movement of the control shaft inserted through the central hole of the rocker shaft. By rotating the input part (cam hitting member) and the two swing cams (valve striking member) relatively by the slider gear, the relative phase difference between them is changed and the lift amount of the valve is adjusted. It is like that.

  In addition, the outer periphery of the slider gear is provided with helical splines in three rows in the axial direction. An input portion is provided at the center helical spline of the slider gear, and two swing cams are provided at the two side helical splines of the slider gear. Are splined. The inclination directions of the two side helical splines are opposite to the center helical spline.

  In addition, a compression coil spring for bringing the input portion into contact with the cam of the camshaft is installed in the vicinity of the input portion.

This compression coil spring can be stored in a compressed state, for example, in a bottomed cylindrical holder installed in a cylinder head without being exposed. In this case, the one end side winding part which protrudes from the opening side of a holder in a compression coil spring comes to contact | abut to the spring receiving piece of an input part. Note that the compression coil spring can be easily pulled out only by being housed in the holder.
JP 2001-263015 A

  In the above conventional example, since the compression coil spring and the holder can be separated, they cannot be handled by the assembly, and care must be taken so that the compression coil spring does not come out when the assembly is transported or assembled to the internal combustion engine. It can be said that handling is troublesome.

  An object of the present invention is to facilitate handling in a variable valve mechanism of an internal combustion engine at the time of conveyance or assembly to the internal combustion engine.

  The present invention is a variable valve mechanism that can change the operating characteristics of an intake valve or an exhaust valve of an internal combustion engine, and has a control shaft in a central hole of a rocker shaft fixedly supported in parallel with a camshaft on a cylinder head. The slider gear is fitted on the outer periphery of the rocker shaft so as to be interlocked with the control shaft, and the cam hitting member and the valve hitting member are adjacent to each other in the axial direction on the slider gear. It is configured so as to be externally arranged through a helical spline, to change the relative phase difference of the valve striking member with respect to the cam striking member by displacing the control shaft in the axial direction, and to attach the cam striking member to the camshaft. An urging mechanism for contacting the cam; the urging mechanism urges the cam hit member toward the cam; A spring that, the disposed in the vicinity of the cam to be hit member and a holder having a recess in which the spring is housed, the spring is characterized by being attached to the non-isolated to the holder.

  According to this configuration, since the spring and the holder constituting the urging mechanism are not separated, the handling of the urging mechanism is performed when the urging mechanism is transported alone or when the urging mechanism is assembled to the internal combustion engine. Is easy and there is no worry of losing parts, such as springs coming out.

  Preferably, the urging mechanism includes a pad that comes into contact with a spring receiving piece provided in the cam hitting member in a state of being non-separably attached to an end portion of the spring located on the opening side of the concave portion of the holder. Furthermore, it can be set as the structure containing.

  According to this configuration, since the entire pad can be brought into contact with the spring receiving piece of the cam hit member, the area of the contact portion can be made as large as possible. Accordingly, it is possible to efficiently transmit the biasing force of the spring to the spring receiving piece, and it is possible to improve the wear resistance of the spring receiving piece and the pad, which is preferable.

  Preferably, the holder is installed in a posture in which the concave opening side is opened downward, and an end side of the spring located on the concave opening side of the holder is in contact with the cam hit member.

  In this configuration, if the spring is not held in the non-separated state as in the conventional example, the spring is easily removed from the holder when the biasing mechanism is installed above the cam hitting member. Although it is feared that it becomes difficult, with the above configuration, since the spring is not separated from the holder, the above-described problems are avoided.

  Preferably, the holder has a bottomed cylindrical portion, and the spring is a compression coil spring that is accommodated in the cylindrical portion of the holder so as to be extendable and contractible.

  In this configuration, the holder is specified to have a simple shape, and the spring is specified to have a general fixed shape, so that it is relatively easy to manufacture and obtain the biasing mechanism. This is advantageous in controlling costs.

  Preferably, a convex portion smaller than the inner diameter of the cylindrical portion is provided on the inner bottom portion of the cylindrical portion of the holder, and the one end side end winding portion of the spring is fitted to the convex portion so as to be non-separated. .

  In this configuration, it is possible to easily secure the holding structure of the spring with respect to the holder, and also as a method of attaching the spring to the convex portion, it is easy to strongly press the spring at the end of the process of storing the spring in the holder. Yes.

  Preferably, the pad is made of a cylindrical member with a bottom and is fitted and inserted into the cylindrical portion opening side of the holder in a state of being covered with the end winding portion of the spring.

  According to this configuration, when the spring expands and contracts, the outer peripheral surface of the cylindrical portion of the pad is slidably guided by the inner peripheral surface of the cylindrical portion of the holder. The followability to the movement of the striking member is good.

  Preferably, a convex portion smaller than the inner diameter of the cylindrical portion is provided on the inner bottom portion of the pad, and the other end side end winding portion of the spring is fitted on the convex portion so as to be non-separated. .

  In this configuration, it is possible to easily secure the pad holding structure for the spring held by the holder, and the convex portion is attached to the spring on the inner diameter side of the other end side winding portion. It can be done easily by pushing the part.

  According to the present invention, since the components of the urging mechanism are not separated, it is possible to facilitate handling when the urging mechanism is transported or assembled to the internal combustion engine, which contributes to improvement in productivity. it can.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 to 12 show an embodiment of the present invention.

  First, prior to the description of the characteristic part of the present invention, the configuration of an example of a variable valve mechanism for an internal combustion engine which is a premise of the present invention will be described. Here, as shown in FIGS. 1 and 2, an in-line four-cylinder DOHC engine is taken as an example of the internal combustion engine 1.

  The variable valve mechanism 30 can continuously change the operation characteristics such as the lift amount and the working angle of only the intake valve 11 out of the intake valve 11 and the exhaust valve 12. As described in detail in Japanese Patent No. -263015, for example, as shown in FIGS. 1 to 8, a rocker shaft 31, a control shaft 32, an actuator 33, a valve lift mechanism 34, and the like are provided.

  The variable valve mechanism 30 can also be provided on the exhaust valve 12 side, but the description here is omitted.

  The rocker shaft 31 is attached to a number of partition walls 2c provided at regular intervals along the arrangement direction of the cylinders # 1 to # 4 in the cylinder head 2 so as to be immovable in the axial direction and the circumferential direction. It is arranged in parallel with the intake camshaft 13 and the exhaust camshaft 14, that is, along the arrangement direction of the cylinders # 1 to # 4.

  The control shaft 32 is inserted into the center hole of the rocker shaft 31 formed of a hollow pipe so as to be axially displaceable, and is driven forward and backward in the axial direction by the actuator 33.

  The number of valve lift mechanisms 34 is the same as the number of cylinders, and is externally mounted on the rocker shaft 31 so as to correspond to the cylinders # 1 to # 4.

  The valve lift mechanism 34 is disposed between the intake cam 13a of the intake camshaft 13 and the rocker arm 18, and includes an input arm 41 as a cam hit member and two output arms 42A and 42B as valve hitting members. And a slider gear 43.

  The rocker arm 18 has one end supported by a hydraulic lash adjuster 19, the other end abutted against a tappet 11 a on the stem end side of the intake valve 11, and a roller 18 a rotatably supported in the middle in the longitudinal direction. So, it is a so-called end pivot type. The hydraulic lash adjuster 19 has a known configuration that functions to always keep the tappet clearance of the intake valve 11 at zero.

  The input arm 41 has a cylindrical housing 41 a, and a helical spline 41 b that meshes with the center helical spline 43 a of the slider gear 43 is formed on the inner peripheral surface thereof. A pair of forks 41cL and 41cR projecting radially outward is provided on the outer periphery of the housing 41a, and a support shaft 41d parallel to the rocker shaft 31 is interposed between the pair of forks 41cL and 41cR. A roller 41e is rotatably supported.

  The two output arms 42A and 42B have the same shape, and both have a cylindrical housing 42a, and a helical spline 42b that meshes with the side helical spline 43b of the slider gear 43 is formed on the inner peripheral surface thereof. ing. Further, a nose 42c is provided on the outer periphery of the housing 42a as a protruding piece that protrudes radially outward. The nose 42c is formed in a substantially triangular shape in a side view, and one side thereof is a cam surface 42d. The cam surfaces 42d of the output arms 42A and 42B are in contact with the rollers 18a of the rocker arm 18.

  The slider gear 43 is externally mounted on the rocker shaft 31 so as to be movable in the axial direction in conjunction with the control shaft 32, and the input arm 41 and the two output arms 42A and 42B are externally mounted on the outer diameter side thereof. .

  The slider gear 43 is formed in a cylindrical shape having a through hole 43c at the center, and a center helical spline 43a that meshes with the helical spline 41b of the input arm 41 is provided at the center in the axial direction on the outer periphery, and a shaft on the outer periphery. Side helical splines 43b meshing with the helical splines 42b of the output arms 42A and 42B are formed on both sides in the direction. The side helical spline 43b has a smaller outer diameter than the center helical spline 43a. The center helical spline 43a and the side helical spline 43b are formed so that the inclination directions of the teeth are opposite.

  The roller 41e of the input arm 41 is urged so as to be always pressed against the intake cam 13a by an urging mechanism 50 called a lost motion mechanism installed in the cylinder head 2. The roller surface 18a of the rocker arm 18 is pressed against the cam surface 42d of the housing 42a of the output arms 42A and 42B by the valve spring 11b of the intake valve 11.

  Here, the slider gear 43 will be described in connection with the rocker shaft 31 and the control shaft 32.

  In the slider gear 43, between the center helical spline 43a and one side helical spline 43b, there is provided a long hole 43d that extends along the circumferential direction and penetrates radially inward and outward. In the rocker shaft 31, a long hole 31a that extends along the axial direction and penetrates radially inward and outward is provided at a position corresponding to the long hole 43d of the slider gear 43. Further, an insertion hole 32 a is provided at a position of the control shaft 32 corresponding to the long hole 31 a of the rocker shaft 31.

  Then, the rocker shaft 31 is inserted into the through hole 43c of the slider gear 43, and a locking pin 44 is inserted at a location where the long hole 43d of the slider gear 43 and the long hole 31a of the rocker shaft 31 intersect. One end of the pin 44 is fixed to the insertion hole 32 a of the control shaft 32 inserted into the control shaft 32. In order to allow movement of the locking pin 44 in the long hole 43 d of the slider gear 43, the axial width of the long hole 43 d of the slider gear 43 is slightly larger than the diameter of the locking pin 44.

  The slider gear 43 assembled in this way moves in the axial direction in conjunction with the control shaft 32 when the control shaft 32 is moved in the axial direction, and the torque of the intake camshaft 13 is transmitted to the input arm 41. When it is done, it swings around the rocker shaft 31.

  In such a valve lift mechanism 34, the slider gear 43 is moved in the axial direction together with the control shaft 32, and the relative position in the axial direction between the slider gear 43 and the arm assembly (input arm 41 and output arms 42A and 42B) is changed. By doing so, torsional forces in opposite directions are applied to the input arm 41 and the output arms 42A and 42B. As a result, the input arm 41 and the output arms 42A and 42B rotate relative to each other, and the relative phase difference between the input arm 41 (roller 41e) and the output arms 42A and 42B (nose 42c) is changed.

  In the variable valve mechanism 30, the valve lift mechanism 34 for each cylinder is fixed to one common control shaft 32, so that all cylinders are moved along with the axial movement of the control shaft 32. The lift amount of the intake valve 11 is changed at the same time. However, it is also possible to individually operate the valve lift mechanism 34 for each cylinder.

  Next, the basic operation will be described.

  First, in the state where the control shaft 32 is moved to the maximum in the direction away from the actuator 33 (the arrow F direction in FIG. 3), the roller 41e of the input arm 41 around the axis of the rocker shaft 31 and the output arm 42A, The relative phase difference with the nose 42c of 42B becomes the maximum.

  In such a state, as shown in FIG. 7A, the rocker arm 18 does not tilt while the base circle portion of the intake cam 13a is in contact with the roller 41e of the input arm 41. Becomes zero (the intake port 2a is closed).

  Here, as shown in FIG. 7B, when the roller 41e of the input arm 41 is pushed down to the maximum by the convex portion of the intake cam 13a as the intake cam shaft 13 rotates clockwise, the input arm 41 is While rotating in the direction of the arrow A (counterclockwise), the output arms 42A and 42B and the slider gear 43 are rotated together. As a result, as shown in FIG. 7B, the roller 18a of the rocker arm 18 is pushed down by the nose 42c of the output arms 42A and 42B, and the rocker arm 18 is tilted with the contact portion with the lash adjuster 19 as a fulcrum, and the intake valve 11 is pushed down to open at the maximum lift and operating angle.

  On the other hand, in the state where the control shaft 32 is moved to the maximum in the direction approaching the actuator 33 (the arrow R direction in FIG. 3), the relative phase difference between the roller 41e and the nose 42c around the axis of the rocker shaft 31 is minimum. Become.

  In this state, as shown in FIG. 8A, the rocker arm 18 does not tilt while the base circle portion of the intake cam 13a is in contact with the roller 41e of the input arm 41. Becomes zero (the intake port 2a is closed).

  Here, as shown in FIG. 8B, when the roller 41e of the input arm 41 is pushed down to the maximum by the convex portion of the intake cam 13a as the intake cam shaft 13 rotates in the clockwise direction, Although the output arms 42A and 42B are integrally rotated in the counterclockwise direction (arrow A direction), the nose 42c does not contact the roller 18a of the rocker arm 18, so the rocker arm 18 does not tilt at all, and the intake valve 11 The lift amount is maintained at zero.

  Next, a configuration related to the characteristic part of the present invention will be described with reference to FIGS. In these drawings, only one valve lift mechanism 34 is shown for easy understanding.

  About the biasing mechanism 50 with which the variable valve mechanism 30 mentioned above is equipped, it has devised so that the component can be handled as non-separation.

  As shown in FIG. 11, the urging mechanism 50 includes a spring 51, a holder 52, and a pad 53.

  The spring 51 is a cylindrical compression coil spring, and one end side end winding portion of the spring 51 is non-separably attached to the holder 52 in a state where the spring 51 is housed in the holder 52.

  The holder 52 has a bottomed cylindrical portion 52a having a recess in which the spring 51 can be accommodated, and mounting pieces 52b projecting radially outward at two openings on the outer periphery of the cylindrical portion 52a. is doing.

  The pad 53 is made of a bottomed cylindrical member that can accommodate the spring 51, and is inserted into the opening side of the cylindrical portion 52 a of the holder 52 while covering the other end side end winding portion of the spring 51. . The pad 53 is non-separably attached to the other end side end winding portion of the spring 51.

  Such an urging mechanism 50 is assembled on the cylinder head 2 as follows. That is, as shown in FIG. 10 and FIG. 12, by placing the holder 52 above the valve lift mechanism 34 in such a posture that the opening side of the cylindrical portion 52a is vertically downward, the pad 53 is lowered. The two mounting pieces 52b of the holder 52 are placed on two adjacent partition walls 2c on the cylinder head 12 and positioned and fixed by fastening members 54 such as bolts. In this state, the bottom outer surface of the pad 53 is brought into contact with the spring receiving piece 41f of the input arm 41 by the surface.

  In such an assembled state, the urging force with respect to the input arm 41 changes due to the elastic restoring force accompanying the compression of the spring 51 made of a compression coil spring. Incidentally, the elastic restoring force of the spring 51, that is, the urging force against the input arm 41 becomes stronger as the compression amount of the spring 51 is increased, and becomes weaker as the compression amount of the spring 51 is reduced. It is set appropriately.

  Here, a structure for attaching the spring 51 to the holder 52 in a non-separable manner and a structure for attaching the spring 51 to the pad 53 in a non-separable manner will be described in detail below.

  First, a convex portion 52c smaller than the inner diameter of the cylindrical portion 52a is provided on the inner bottom portion of the cylindrical portion 52a of the holder 52, and one end side (from FIG. 10) of the compression coil spring as the spring 51 is provided on the outer periphery of the convex portion 52c. In FIG. 12, the end winding portion at the upper end is fitted and fixed by press fitting.

  Further, an annular convex portion 53a smaller than the inner diameter of the cylindrical portion is provided on the inner bottom portion of the pad 53, and the other end side of the compression coil spring as the spring 51 (see FIGS. 10 to 12) on the outer periphery of the annular convex portion 53a. Then, the end winding part is fitted and fixed by press-fitting.

  The material of the holder 52 and the pad 53 is not particularly limited as long as it has a predetermined strength. And the convex part 52c of the holder 52 and the ring-shaped convex part 53a of the pad 53 can be easily obtained by transfer from a molding die when the holder 52 and the pad 53 are manufactured by a molding method. However, after the holder 52 and the pad 53 are manufactured by some method such as drawing or molding, the convex portions 52c and the annular convex portions 53a are formed by turning the inner bottom portions thereof. Good.

  By the way, by forming the convex portion 52 c on the inner bottom portion of the holder 52, the width of the groove formed between the outer periphery of the convex portion 52 c and the inner periphery of the cylindrical portion 52 a and the ring-shaped convex portion on the inner bottom portion of the pad 53. By forming the portion 53 a, the width of the groove formed between the outer periphery of the ring-shaped convex portion 53 a and the inner periphery of the cylindrical portion of the pad 53 is more appropriately than the wire diameter of the compression coil spring as the spring 51. It is set large. Thereby, the outer diameter side of the spring 51 is not in contact with the inner peripheral surface of the cylindrical portion 52 a of the holder 52 and the inner peripheral surface of the cylindrical portion of the pad 53.

  And about the fitting part of the spring 51 with respect to the convex part 52c of the holder 52, and the fitting part of the spring 51 with respect to the ring-shaped convex part 53a of the pad 53, it is not "positive clearance" but "zero clearance" or "negative clearance". However, the end edge of the end portion of the spring 51 does not float from the bottom surface of the groove of the holder 52 and the bottom surface of the groove of the pad 53 by causing a so-called “galling” at the time of fitting. In particular, it is preferable to set the end portions of the end portions of the spring 51 so as to be surely brought into contact with the bottom surface of the groove of the holder 52 and the bottom surface of the groove of the pad 53, respectively.

  With this setting, when the spring 51 expands and contracts, the elastic restoring force of the spring 51 is reliably transmitted to the holder 52 and the pad 53.

  Next, the assembly procedure of the urging mechanism 50 will be described below.

  First, for example, the holder 52 is placed in an attitude in which the opening side of the cylindrical portion 52a is disposed upward, and the spring 51 is stored in the cylindrical portion 52a from above. In the final stage of the storing process, the spring 51 is stored. Press down strongly. As a result, the end winding portion of one end of the spring 51 (the upper end side in FIGS. 10 to 12) is press-fitted and fitted to the outer periphery of the convex portion 52 c of the cylindrical portion 52 a, whereby the spring 51 is fitted to the holder 52. It will be attached non-separately.

  On the other hand, with the spring 51 attached to the holder 52 as described above, the pad 53 is disposed above the spring 51 so that the opening faces downward, and the pad 53 is lowered to move the spring into the cylindrical portion. The other end side of 51 (the lower end side in FIGS. 10 to 12) is stored, and the pad 53 is strongly pressed downward in the final stage of the storing process. As a result, the ring-shaped convex portion 53a of the pad 53 is press-fitted and fitted into the inner periphery of the end winding portion on the other end side (the lower end side in FIGS. 10 to 12) of the spring 51. 53 will be attached non-separately.

  As described above, since the components (spring 51, holder 52, pad 53) of the urging mechanism 50 are not separated from each other, they become an integral part and can be handled easily.

  In addition, since the spring 51 and the pad 53 can be prevented from coming out of the holder 52 when the urging mechanism 50 is transported or assembled to the cylinder head 2, there is no need to worry about losing these parts, and the internal combustion engine is manufactured. This is advantageous in improving reliability.

  Hereinafter, other embodiments of the present invention will be described.

  (1) In the above embodiment, an example is given in which the pad 53 is installed in a state of protruding downward in the vertical direction, but the installation state of the pad 53 is not particularly limited. If the pad 53 is installed in a state of protruding upward, its components are difficult to separate at the time of assembly of the biasing mechanism 50, so that the effect of facilitating assembly by non-separation is lost, but in the transport process. The effect that handling becomes easy is acquired.

  (2) The spring 51 shown in the above embodiment is not limited to a cylindrical compression coil spring, and may be various springs other than a generally known leaf spring or disc spring. In that case, in consideration of the shape of the spring 51 to be selected, it is preferable to appropriately set an attachment form in which the spring 51, the holder 52, and the pad 53 are not separated.

It is a top view showing typically an internal-combustion engine provided with a variable valve mechanism concerning the present invention. It is an arrow view of the (2)-(2) line cross section of FIG. It is a perspective view of the variable valve mechanism of FIG. It is a disassembled perspective view of the valve lift mechanism of FIG. FIG. 5 is an exploded perspective view showing a relationship between a slider gear and a rocker shaft of the valve lift mechanism of FIG. 4. It is a perspective view which fractures | ruptures and shows the upper half of the valve lift mechanism of FIG. FIG. 3 is a side view used for explaining the operation when the relative phase difference between the input arm and the output arm in FIG. 2 is maximized. FIG. 3 is a side view used for explaining the operation when the relative phase difference between the input arm and the output arm in FIG. 2 is minimized. FIG. 2 is an enlarged plan view showing a valve lift mechanism and an urging mechanism for one cylinder in FIG. 1. FIG. 10 is a cross-sectional view taken along line (10)-(10) in FIG. 9. It is a disassembled perspective view which shows the urging | biasing mechanism in FIG. It is explanatory drawing which shows a mode at the time of attaching the urging mechanism of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Internal combustion engine 2 Cylinder head 2c Partition 11 Intake valve 12 Exhaust valve 13 Intake cam shaft 13a Intake cam 30 Variable valve mechanism 31 Rocker shaft 32 Control shaft 33 Actuator 34 Valve lift mechanism 41 Input arm (cam hitting member)
42 Output arm (valve striking member)
43 Slider gear 50 Biasing mechanism 51 Spring 52 Holder 52a Holder cylindrical part 52c Holder convex part 53 Pad 53a Pad-like convex part

Claims (7)

A variable valve mechanism capable of changing the operating characteristics of an intake valve or an exhaust valve of an internal combustion engine,
A control shaft is inserted in the center hole of the rocker shaft fixedly supported on the cylinder head in parallel with the camshaft so as to be axially displaceable, and a slider gear is mounted on the outer periphery of the rocker shaft so as to be interlocked with the control shaft. A cam hitting member and a valve hitting member are externally mounted on a slider gear through a helical spline whose axial direction is adjacent to each other in the axial direction, and the control shaft is displaced in the axial direction so that the valve hitting member with respect to the cam hitting member It is configured to change the relative phase difference of
And a biasing mechanism for bringing the cam hit member into contact with the cam of the camshaft, the biasing mechanism comprising a spring for biasing the cam hit member toward the cam, and the cam hitting A variable valve mechanism for an internal combustion engine, comprising a holder having a concave portion that is installed in the vicinity of the member and that accommodates the spring, wherein the spring is non-separably attached to the holder.   The biasing mechanism according to claim 1 is in contact with a spring receiving piece provided in the cam hitting member in a state of being non-separably attached to an end portion of the spring located on the opening side of the concave portion of the holder. A variable valve mechanism for an internal combustion engine, further comprising a pad.   The holder according to claim 1 or 2 is installed in a posture in which the recessed opening side is opened downward, and an end portion of the spring located on the recessed opening side of the holder is in contact with the cam hit member. A variable valve mechanism for an internal combustion engine.   4. The internal combustion engine according to claim 1, wherein the holder has a bottomed cylindrical portion, and the spring is a compression coil spring that is retractably accommodated in the cylindrical portion of the holder. 5. Variable valve mechanism of the engine.   In Claim 4, The cylindrical part inner bottom part of the said holder is provided with the convex part smaller than the said cylindrical part internal diameter, and non-separation is carried out by the end-end side winding part of the said spring being externally fitted by this convex part. A variable valve mechanism for an internal combustion engine, which is mounted.   6. The pad according to claim 4, wherein the pad is made of a cylindrical member with a bottom and is fitted and inserted into the cylindrical portion opening side of the holder in a state where the pad is covered with the end winding portion of the other end of the spring. A variable valve mechanism for an internal combustion engine.   7. The pad according to claim 6, wherein a convex portion smaller than the inner diameter of the cylindrical portion is provided on the inner bottom portion of the pad, and the other end side end winding portion of the spring is fitted on the convex portion so as not to be separated. A variable valve mechanism for an internal combustion engine, which is mounted.

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