JP5392496B2 - Variable valve operating device for internal combustion engine - Google Patents

Description

  The present invention relates to a variable valve operating apparatus for an internal combustion engine in which the phase of a movable cam can be varied with reference to a reference cam.

In a reciprocating engine (internal combustion engine) mounted on an automobile, a variable valve gear is being mounted in order to prevent engine exhaust gas and improve pumping loss.
In the variable valve operating device, as disclosed in Patent Documents 1 and 2, a camshaft having a fixed reference cam and a movable cam rotatable around an axis, and the cam phase of the movable cam as a reference cam. On the other hand, there is a structure in which a phase change device to be changed is combined.

The phase change by the movable cam is difficult to realize with a cam structure in which the cam is integrally formed on a normal shaft member. Therefore, the phase change of the movable cam with respect to the reference cam is realized by using a cam shaft in which a separate cam member is assembled to the shaft member.
Specifically, as a camshaft, a shaft member in which an inner camshaft is rotatably housed in an outer camshaft formed of a pipe member as in Patent Documents 1 and 2, and a fixing provided on the outer periphery of the outer camshaft Combined with a connecting cam that connects the movable cam and the inner camshaft while allowing relative displacement between the outer camshaft and the inner camshaft. An assembly structure type camshaft, a so-called assembly camshaft is used. Then, by connecting a phase changing device such as a rotary vane to the end of the shaft member, the phase of the movable cam can be changed based on the reference cam from the relative displacement between the outer cam shaft and the inner cam shaft. ing.

JP 2009-144521 A JP 2009-144522 A

Such a variable valve operating device is required to connect the assembly camshaft and the phase change device with the simplest possible equipment and work. For this purpose, when connecting the assembly camshaft and the phase change device, it is required to keep the assembly camshaft in a predetermined posture.
However, although the outer camshaft of the assembly camshaft can be easily held from the outside, the inner camshaft is rotatably housed in the outer camshaft, so it is difficult to maintain a constant posture, and the phase change device and It is difficult to connect.

  For this reason, when connecting the end portion of the inner cam shaft and the phase change device, a dedicated pressing portion is separately formed on the inner cam shaft, and a dedicated pressing portion is used from the end of the outer cam shaft using a special device. For example, holding the inner camshaft inside the outer camshaft is required to control the movement of the inner camshaft with a dedicated device. However, the rotation of the inner camshaft by this device is special, and the burden on facilities is heavy. In addition, the assembling with the apparatus is inferior in workability and lacks maintainability in the market.

  Therefore, as a simple measure, the inner cam shaft is rotated to a point where the relative displacement with the outer cam shaft is restricted, and the outer cam shaft is held in a state where the movement of the inner cam shaft in one direction is restricted. Thus, it is conceivable to connect the phase change device to the end portion of the inner camshaft with a bolt member or the like. However, when a torque accompanying the connection is applied to the inner cam shaft, the torque is also applied to the outer cam shaft through the connecting member. For this reason, the outer camshaft may be deformed or bent due to contact with the connecting member. Such deformation and bending lead to an increase in friction between the outer cam shaft and the journal bearing portion of the cylinder head, and an increase in friction between the cam and the tappet. The friction may cause abnormal wear between parts, damage to parts due to abnormal wear, and engine damage. Even if it doesn't break, the increase in friction worsens the fuel consumption of the engine.

  Accordingly, an object of the present invention is to eliminate the necessity of separately forming a dedicated holding device or an inner cam shaft pressing portion, and further, the inner cam with an easy and simple structure without any deformation or bending of the outer cam shaft. An object of the present invention is to provide a variable valve operating device for an internal combustion engine that enables connection between an end of a shaft and a phase change device.

In order to achieve the above-mentioned object, the movable cam provided on the outer periphery of the outer shaft constituting the assembly cam shaft is provided with a boss portion that fits on the outer periphery of the outer cam shaft. The connecting member that connects the movable cam and the inner cam shaft while allowing relative displacement between the outer shaft and the inner shaft passes through the boss portion, the outer cam shaft, and the inner cam shaft from the diametrical direction. And a flat seating surface having an entrance through which the pin-shaped member enters and exits at each outer peripheral portion facing each other of the boss portion serving as a penetrating end of the pin-shaped member. provided, communicating with configuration diverted seating surface of the boss, the boss, the held portion for arranging the assembly shaft to a predetermined position is provided, and a phase changing device end of the shaft member To time, when using a planar seating surface to place the assembled camshaft in a predetermined position, the pin-shaped member is configured to function as a rotation stopper of the inner camshaft.
According to the structure, when the position changing device is connected to the end of the shaft member, if the assembly cam shaft is arranged in a predetermined posture using a flat seat surface , the movement of the pin-shaped member is also restricted and the inner cam is controlled. Lock the shaft.

The invention according to claim 2, is et to perform the holding by general equipment so, the seating surface of the boss portion constituting the held portion is formed at least a pair of planar portions to allow clamping the boss It was decided to become.

According to the present invention, when connecting the phase change device assembled camshaft, placing the assembly camshaft in a predetermined orientation with planar seat surface provided in the boss portion of the movable cam, the pin The inner shaft connected to the movable cam is prevented from rotating through the shaped member .
Therefore, the connection between the inner cam shaft and the phase changing device is a simple one in which the flat seating surface of the boss portion of the movable cam disposed on the outer peripheral portion of the outer cam shaft is used as it is for the rotation prevention of the inner cam shaft. Non-rotating structure, easy work. In addition, this connection eliminates the need to form a dedicated holding device or an inner camshaft pressing portion that imposes a burden. Therefore, the workability at the time of cam assembly and the maintainability in the market are improved. In addition, since no external force is applied to the outer camshaft during connection, the outer camshaft is not deformed or bent. In addition, the held portion is configured by diverting the seating surface of the movable cam boss which is a part of the structure connecting the movable cam boss and the inner camshaft with a pin-shaped member. A simple structure that uses parts as they are.

According to the invention of claim 2, held by the general-purpose device you can be performed more with a simple structure.

The top view which shows the variable valve apparatus which concerns on one Embodiment of this invention with the cylinder head of the internal combustion engine carrying the same apparatus. Sectional drawing of the variable valve apparatus which follows the II line | wire in FIG. The perspective view which shows the structure of the variable valve operating apparatus. Similarly disassembled perspective view. The diagram which shows the variable characteristic of a variable valve apparatus. The perspective view explaining when a camshaft and a phase change apparatus are connected. Similarly sectional drawing.

Hereinafter, the present invention will be described based on an embodiment shown in FIGS.
FIG. 1 shows a plan view of an internal combustion engine, for example, a three-cylinder (multi-cylinder) reciprocating engine (hereinafter simply referred to as an engine), and FIG. 2 shows a cross section taken along line I-I in FIG. Reference numeral 1 denotes a cylinder block of the engine, and reference numeral 2 denotes a cylinder head mounted on the head of the cylinder block 1.

Among these, the cylinder block 1 is formed with three cylinders 3 (only some of the cylinders are shown) along the longitudinal direction of the engine as shown in FIGS. 1 and 2. In each cylinder 3, pistons 4 (shown only in FIG. 2) separated from a crankshaft (not shown) via connecting rods (not shown) are housed so as to be able to reciprocate.
A combustion chamber 5 is formed on the lower surface of the cylinder head 2 corresponding to each cylinder 3. Each combustion chamber 5 has a pair of intake ports 7 (two) for performing intake and a pair of exhaust ports (not shown) for performing exhaust. Each intake port 7 is provided with a pair of intake valves 10 (two) to which tappets 9 are attached. The tappet 9 at the top faces the upper part of the cylinder head 2. Each exhaust port (not shown) is similarly provided with a pair of exhaust valves (not shown). The intake port 7 and the exhaust port (not shown) are opened and closed by the intake valve 10 and the exhaust valve (not shown). Each combustion chamber 5 is provided with a spark plug (not shown).

  Further, as shown in FIG. 1, an intake side valve operating device 6a and an exhaust side valve operating device 6b driven by the shaft output of the crankshaft are provided on the upper left and right sides of the cylinder head 2, respectively. 3, a predetermined combustion cycle (four cycles of an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke) is repeatedly performed. Among these valve operating devices 6a and 6b, the exhaust-side valve operating device 6b uses a cam shaft 13 in which a normal pair of exhaust cams 12 are integrally formed (for example, formed by machining). This camshaft 13 is assembled so as to be rotatable in the direction in which the cylinders 3 are arranged, and the cam surface of each exhaust cam 12 is brought into contact with the base end portion of an exhaust valve (not shown). Thus, the cams of the exhaust cams 13 are transmitted to the exhaust valves (not shown).

Unlike the exhaust-side camshaft 13, the intake-side valve gear 6 a is a camshaft constituted by assembling separate members as shown in FIGS. 2 to 4, a so-called assembly cam camshaft 14 ( Hereinafter, the camshaft 14 is simply used. The camshaft 14 is used to constitute a split type variable valve operating device 15.
That is, the camshaft 14 will be described. The shaft member of the camshaft 14 is constituted by a shaft member that forms a control member in an outer camshaft 17a that is constituted by a hollow pipe member as shown in FIGS. The inner camshaft 17b thus formed is formed of a double shaft 17 that is rotatably accommodated. The double shaft 17 is also arranged along the direction in which the cylinders 3 are arranged, like the camshaft 13 on the exhaust side. One end (one side) of the double shaft 17, that is, one end of the outer cam shaft 17 a is connected to one end of the cylinder head 2 via a cam piece 37 attached to the end of the outer cam shaft 17 a. It is rotatably supported by a bearing portion 18a installed on one side. The intermediate portion of the outer camshaft 17a is rotatably supported by an intermediate bearing portion 18b installed between the tappets 9,9. Thus, both shafts 17a, 17b can be rotated about the same axis. In addition, the structure between the outer camshaft 17a and the inner camshaft 17b has a clearance to suppress the occurrence of friction during relative displacement.

The outer cam shaft 17a is provided with a pair (two) of intake cams 19 corresponding to the pair of intake valves 10 for each cylinder. Each of the intake cams 19 is configured by combining a reference cam 20 that defines a reference phase and a cam lobe 22 (corresponding to the movable cam of the present application) that serves as a movable cam.
Among these, the reference cam 20 is fixed to an outer peripheral portion corresponding to a tappet on one side of the outer cam shaft 17a, for example, the tappet 9 on the left side. The reference cam 20 is formed of a plate cam, and is fixed to the outer side of the outer cam shaft 17a by press-fitting, for example, and is fixed immediately above the left tappet 9. The cam surface of the reference cam 20 is in contact with the left tappet 9 so that the cam displacement of the reference cam 20 is transmitted to the left intake valve 10.

  The cam lobe 22 has a cam nose 22a formed by a plate cam. A cylindrical boss portion 22b projecting in the cam width direction is formed on the side portion of the cam nose portion 22a in order to suppress misalignment of the cam nose portion 22a (one side in the drawing), and the entire cam lobe Is configured. The cam lobe 22 is fitted to the outer side of the outer cam shaft 17a so as to be rotatable in the circumferential direction, and the cam peak portion 22a is disposed immediately above the remaining right tappet 9. The cam surface of the cam crest 22a abuts on the right tappet 9, and the cam displacement of the cam crest 22a is transmitted to the right intake valve 10.

  Further, the boss portion 22b of the cam lobe 22 and the inner cam shaft 17b are a pin member 24 (corresponding to the pin-like member and connecting member of the present application) penetrating the boss portion 22b, the outer cam shaft 22a, and the inner cam shaft 22b from the shaft diameter direction. ). The pin member 24 connects the boss portion 22b and the inner cam shaft 22b while allowing relative displacement between the outer cam shaft 17a and the inner cam shaft 17b, for example, by press fitting. Specifically, as shown in FIG. 4, through holes 27a and 27b into which the pin member 24 is press-fitted are formed in the peripheral wall portion of the boss portion 22b and the shaft portion of the inner cam shaft 17b. In the peripheral wall portion of the outer cam shaft 17a, a through hole for allowing the pin member 24 to escape, for example, a pair of long holes 26 extending in the retarding direction is formed. As a result, when the inner cam shaft 17b is displaced relative to the outer cam shaft 17a, the cam phase of the cam peak portion 22a can be varied from the cam phase of the reference cam 20 as a reference to a cam phase greatly retarded. Yes. In particular, the boss portion 22b is provided with a case where the pin member 24 is press-fitted without deformation of parts, as shown in FIGS. 3 and 4, each outer peripheral surface portion (relative to the boss portion 22b serving as a penetrating end of the pin member 24). A flat seat portion, that is, a pair of flat seat surfaces 28 having an entrance / exit 28a of the through hole 27a is formed in the facing portion.

A phase changing device 25 for relatively displacing the inner and outer shafts is connected to one end of the double shaft 17 to constitute a variable valve operating device 15 that can change the cam phase of the cam lobe 22 with respect to the reference cam 20. ing.
That is, the phase changing device 25 includes, for example, a plurality of vanes radially from the outer peripheral portion of the shaft portion 32 in a cylindrical housing 31 having a plurality of retarding chambers 30 in the circumferential direction as shown in FIGS. A rotating vane structure is used in which the vane portion 34 projecting from 33 is rotatably accommodated and each vane 33 partitions the inside of each retarded angle chamber 30.

  The housing 31 is connected to an end portion of the outer cam shaft 17a, here a cam piece 37 attached to the same end portion, by a fixing bolt 36 as a connecting member. The remaining shaft portion 32 of the vane portion 34 is connected to the shaft end of the inner cam shaft 15b by a fixing bolt 38 as a connecting member. By such connection, when the vane 33 is rotationally displaced in the retard chamber 30, the inner cam shaft 15b is displaced relative to the outer cam shaft 15a.

  More specifically, the cam phase of the cam lobe 22 is changed to the cam phase of the reference cam 20 as a reference by the urging force of the return spring member 42 (FIG. 2) provided so as to pass between the housing 31 and the vane portion 34. Aligned. Each retard chamber 30 is provided with an oil control valve 44 (hereinafter referred to as OCV 44) and a hydraulic pressure supply section 45 through various oil passages 43 (shown only in FIG. 2) formed in the housing 31, the cam piece 37 and the bearing portion 18a. (For example, an oil pump that supplies oil). That is, when oil is supplied into each retarded angle chamber 30, splitting is performed such that the cam lobe 22 is displaced from the reference cam 20 in the retarded direction as shown in the diagram of FIG.

  That is, the shaft output from the crankshaft (not shown) is, for example, from the timing sprocket 39 provided in the housing 31 and the timing chain 40 spanned on the timing sprocket 13a provided at the end of the exhaust camshaft 13 to the housing 31, It is transmitted to the outer shaft 17 a via the cam piece 37, and the reference cam 20 is rotationally driven to open and close the left intake valve 10 via the tappet 9. Here, when the hydraulic pressure is supplied from the OCV 44 to the advance chamber on the opposite side of each retard chamber 30, the cam lobe 22 is as shown in the state A in FIG. 4 in cooperation with the urging force of the return spring member 42. Since it rotates together with the reference cam 20 while being aligned with the cam phase of the reference cam 20, the right intake valve 10 b is opened and closed while maintaining the same phase as the left reference cam 20. When the hydraulic pressure is output from the hydraulic pressure supply unit 45 into the retard chamber 30 through the OCV 44, the vane 33 is displaced from the initial position to the retard side in accordance with the supplied hydraulic pressure. At this time, for example, when the vane 33 is displaced halfway in the retard chamber 30 by controlling the supply hydraulic pressure, the inner camshaft 17b is displaced in the retard direction to the midpoint position. The displacement of the inner cam shaft 17b at this time is transmitted to the pin member 24, and the cam peak portion 22a of the cam lobe 22 is driven in the retarding direction by the output of the pin member 24 output from the inner cam shaft 17b. Due to this cam phase, as shown in the state B in FIG. 4, the opening / closing timing of the left intake valve 10 as a reference remains unchanged, and only the opening / closing timing of the right intake valve 10b changes. That is, the right intake valve 10 is opened / closed according to the cam profile of the cam peak portion 22a in the middle of the opening / closing period of the left intake valve 10. When the vane 33 is displaced to the most retarded position by controlling the supply hydraulic pressure, the opening and closing timing of the left intake valve 10 remains unchanged as shown in the state C in FIG. Opens and closes at the most retarded time from the left intake valve 10a while maintaining a state in which the left intake valve 10 is opened and closed. That is, the left and right intake valves 10 are varied within the range from the smallest valve opening period α to the largest valve opening period β (split variable) according to the state of the engine.

Since the camshaft 14 of the variable valve operating apparatus 15 has a unique structure in which the inner camshaft 17b is rotatably accommodated in the outer camshaft 17a, the inner camshaft 17b is easily rotationally displaced. For this reason, when connecting the end part of the inner camshaft 17b of the camshaft 14 and the phase changing device 25, there is a difficulty in work.
Therefore, the camshaft 14 is devised so that the inner camshaft 17b can be prevented from rotating with a simple operation. For this purpose, as shown in FIGS. 3 and 4, when the operation of connecting the end of the double shaft 17 and the phase changing device 25 to each cam lobe 22 is performed, the entire double shaft 17 is in a predetermined posture. Therefore, a held portion 52 that can be held by a general-purpose device is provided, and the holding by the held portion 52 is used as it is as a detent for the inner cam shaft 17b.

  Specifically, each of the held portions 52 is provided on a boss portion 22d formed to suppress the occurrence of misalignment of the cam crest portion 22a. The held portion 52 is formed by forming a pair of parallel flat portions 53 (width across flats) on the opposing outer peripheral portions of the boss portion 22b. Thus, the boss portion having the pair of flat portions 53 can be clamped from both sides by a clamp device which is a general-purpose device. The entire camshaft 14 is maintained in a predetermined posture by the clamp performed at the boss portion 22b. As a result, workability during assembly and maintenance in the market can be improved. Further, since the held portion 52 is provided at a position away from the cam crest portion 22a, the possibility of accidentally scratching the cam crest and the tappet during maintenance in the market can be greatly reduced.

  Here, the structure in which the boss portion 22b and the inner camshaft 17b as shown in FIG. 2 are connected by press-fitting or insertion of the pin member 24 allows the pin member 24 to be inserted to a predetermined position with a general-purpose device. As described above, a pair of seating surfaces 28 each having an entrance / exit 28a (which communicates with the through hole 27a) through which the pin member 24 enters and exits are provided at the opposing outer peripheral portions of the boss portion 22b serving as a penetrating end of the pin member 24. It is formed. In such a case, the seat surface 28 is used as the flat portion 53 (held portion 52) without forming the flat portion 53 separately. In this case, it is not necessary to separately form a pair of flat portions 53, and the length of the boss portion 22b can be set short, which is advantageous in terms of weight and space. Further, deformation of the boss portion 22b clamped by the pin member 24 can be suppressed. In the present embodiment, an example in which the flat surface portion 53 is configured from the pair of seating surfaces 28 is given.

When such a held portion 52 is used, the end portion of the double shaft 17 and the output portion of the phase changing device 25 can be easily connected as shown in FIGS. 6 and 7.
That is, when assembling the variable valve assembly shown in FIG. 3, when connecting the end of the double shaft 17 and the output of the phase changing device 25 during cam assembly, as shown in FIGS. A general-purpose device (not shown) clamps the pair of flat portions 53 of each cam lobe 22 assembled to the outer peripheral portion of the outer cam shaft 17a, and arranges the entire cam shaft 14 in a predetermined posture suitable for connection. . The phase change device 25 is disposed at the end of the camshaft 14 on the cam piece 37 side, and is formed at the bolt hole 47 formed in the shaft center portion of the housing 31 of the phase change device 25 and the shaft end of the inner camshaft 17b. The screw hole 17c is positioned. The plurality of bolt holes 48 formed in the outer peripheral portion of the housing 31 and the screw holes 37c formed in the arm portion 37a projecting outside the cam piece 37 are positioned. Thereafter, when the fixing bolt 36 is screwed from each bolt hole 48, the phase changing device 25 and the end of the outer cam shaft 17a are connected. Further, the fixing bolt 38 is screwed from the bolt hole 47 at the center of the housing 31 into the screw hole 17c of the inner cam shaft 17b.

  At this time, since the pin member 24 is connected to the boss portion 22 b of the cam lobe 22, the movement of the pin member 24 is restricted by the holding by the flat surface portion 53. Further, since the pin member 24 is connected to the inner cam shaft 17b that is rotatably accommodated, the inner cam shaft 17b is prevented from rotating by the restriction of the pin member 24. By this rotation prevention, the fixing bolt 38 is screwed into the screw hole 17c of the inner cam shaft 17b as shown in FIG. 3, and the vane portion 34 of the phase changing device 25 is connected to the end portion of the inner cam shaft 17b.

  As described above, the held portion 52 is not only used as a part used to arrange the camshaft 14 in a predetermined posture, but also used as a detent for the inner camshaft 17b as it is. The inner camshaft 17b and the phase changing device 25 can be connected without using a device. In addition, since a separate detent work is not required, it can be easily connected. In addition, since no external force is applied to the outer cam shaft 17a at the time of connection, the outer cam shaft 17a is not deformed or bent, and the outer cam shaft 17a and the journal bearing portion 18b of the cylinder head 2 are connected. It is possible to suppress an increase in friction between the two cams and an increase in friction between the cam (cam peak portion 22a; movable cam) and the tappet. Thereby, abnormal wear of each part due to friction, damage to the part due to abnormal wear, and further engine damage can be prevented.

  Further, if the held portion 52 is the cam lobe 22 in which the boss portion 22a is formed, a simple structure is required in which the held portion 52 is formed on the boss portion 22b. Moreover, when a pair of flat portions 53 are formed on the outer peripheral portion of the boss portion 22b to form the held portion 52, a structure suitable for holding by a general-purpose device can be achieved. If each of the plurality of cam lobes 22 has a held portion 52 in a multi-cylinder engine, the held portion 52 of any cylinder can be supported by a general-purpose device without rotating the cam. Becomes easy.

In particular, when a pair of seating surfaces 28 are already formed on the outer peripheral portion of the boss portion 22b, the seating surfaces 28 can be used as they are for the flat surface portion 53, and can be applied to existing parts without any processing. There is an advantage that the holding portion 52 can be configured.
Furthermore, if the cam crest portion 22a is formed with reference to the pair of flat portions 53 on the outer peripheral portion of the boss portion 22b of the cam lobe 22 or the through hole 27a of the pin member 24, the cam crest portion 22a is assembled during cam assembly. The accuracy of the direction can be inspected and confirmed by the flat portion 53 or the through hole 27a, and the productivity of the camshaft 14 is improved.

  Note that the present invention is not limited to the above-described embodiment, and various modifications may be made without departing from the spirit of the present invention. For example, in one embodiment, an example in which the held portion is configured from a pair of flat portions has been described. However, the present invention is not limited to this, and as long as the cam lobe can be held or prevented from rotating, two or three pairs of flat portions or other You may comprise a to-be-held part from this structure. Moreover, although one embodiment gave the example which applied this invention to the variable valve apparatus of the intake side, if it is an engine by which the variable valve apparatus is employ | adopted not only to this but an exhaust side, it is an exhaust side. The present invention may be applied to a variable valve operating apparatus.

14 Camshaft (assembled camshaft)
15 Variable valve operating device 17 Double shaft (shaft member)
17a Outer camshaft 17b Inner camshaft 20 Reference cam 22 Cam lobe (movable cam)
22b Boss part 24 Pin member (pin-like member, connecting member)
28 Seat surface 28a Entrance / exit 25 Phase change device 52 Held part 53 Plane part

Claims (2)

A shaft member that is configured such that an inner cam shaft is rotatably accommodated in the outer cam shaft, a reference cam that is provided on the outer peripheral portion of the outer cam shaft, and a rotary member that is rotatably provided on the outer peripheral portion of the outer cam shaft. An assembly camshaft comprising a movable cam, and a connecting member that connects the movable cam and the inner camshaft while allowing relative displacement between the outer camshaft and the inner camshaft;
A phase change device connected to an end of the shaft member and relatively displacing the outer cam shaft and the inner cam shaft;
A variable valve operating apparatus for an internal combustion engine configured such that the phase of the movable cam is variable with respect to the reference cam by the relative displacement,
The movable cam has a boss portion that fits on an outer peripheral portion of the outer cam shaft,
The connection member is inserted from the diameter direction of the shaft member, and includes a pin-shaped member that passes through the boss portion, the outer cam shaft, and the inner cam shaft and connects the movable cam and the inner cam shaft. And
A flat seat surface having an entrance through which the pin-shaped member enters and exits is provided on each outer peripheral portion of the boss portion facing each other as a penetrating end of the pin-shaped member,
In the configuration using the seat surface of the boss part, a held part for arranging the assembly shaft in a predetermined posture is provided on the boss part ,
When the end portion of the shaft member and the phase change device are connected, if the assembly cam shaft is arranged in a predetermined posture using the planar seating surface , the pin-shaped member serves as a detent for the inner cam shaft. A variable valve operating apparatus for an internal combustion engine, which is configured to function. 2. The variable motion of the internal combustion engine according to claim 1 , wherein a seating surface of the boss portion constituting the held portion forms at least a pair of flat portions that allow the boss portion to be clamped. Valve device.

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