Internal combustion engine and method for determining rotation direction phase of axial member

Abstract

To position an axial member at a reference phase when a power supply to an internal combustion engine is suddenly interrupted due to a power outage or other incidents.SOLUTION: An engine 100 comprises: an actuator 7; a rotating shaft 6 that is rotationally driven by the actuator 7; and a positioning mechanism 20 that positions the rotating shaft 6 at a reference phase, which serves as a reference for displacement in a rotational direction, by engaging with the rotating shaft 6 in the rotational direction thereof.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to an internal combustion engine and a method for determining the phase of a shaft member in the rotational direction.

Background Art

[0002] As a valve operating system of an engine, a variable valve timing mechanism capable of changing the valve timing of an intake valve and an exhaust valve according to the operating state of the engine is known.

[0003] For example, in the valve operating device of Patent Document 1, an eccentric rocker shaft is rotated by an actuator to vary the fulcrum position of the rocker arm. Thereby, it is possible to selectively use low- and medium-speed cams and high-speed cams with different cam profiles and change the valve timing of the valve operating device.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In such an internal combustion engine, by the device side recognizing the current rotational phase of the shaft member, it was possible to drive the drive source on the device side to rotate the shaft member to an appropriate phase and change it to a desired valve timing. However, when the power supply to the device suddenly stops due to a power failure or the like, the device side loses sight of the current rotational phase of the shaft member. At this time, by aligning the shaft member with a reference phase that serves as a reference in the rotational direction and causing the device side to recognize that the shaft member is arranged at the reference phase, it is possible to align the actual phase of the shaft member with the phase recognized by the device side again. However, in a conventional internal combustion engine, in such a situation, the shaft member could not be positioned at the reference phase.

[0006] Under such circumstances, an object of the present invention is to position the shaft member at a reference phase when the power supply to the internal combustion engine suddenly stops due to a power failure or the like.

Means for Solving the Problem

[0007] To solve the above problems, the present invention provides an internal combustion engine comprising a drive source, a shaft member rotationally driven by the drive source, and a positioning mechanism that positions the shaft member at a reference phase serving as a reference for displacement in the rotational direction by engaging with the shaft member in the rotational direction.

[0008] According to the present invention, by mechanically engaging the shaft member with the positioning mechanism, the shaft member can be accurately positioned at the reference phase. Therefore, for example, even in a state where no power supply is received, the shaft member can be manually positioned at the reference phase. Also, after the power is restored, the shaft member can be rotated by the drive source and positioned at the reference phase. Then, after positioning the shaft member at the reference phase, by making the device side recognize that the shaft member is arranged at the reference phase, the actual phase of the shaft member and the phase recognized by the device side can be made to match.

[0009] In the above internal combustion engine, the shaft member has a recess recessed in its radial direction and an engaging surface forming the recess, the positioning mechanism has a positioning portion, and the positioning portion engages with the engaging surface in the rotational direction of the shaft member and has a first reference surface for positioning the shaft member at the reference phase. By engaging the first reference surface of the positioning portion with the engaging surface of the shaft member, the shaft member can be positioned at the reference phase.

[0010] The internal combustion engine may be configured such that the positioning portion has an insertion portion that is provided on the tip side closer to the shaft member than the first reference plane and has a smaller diameter than the portion of the positioning portion where the first reference plane is provided, and is inserted into the concave portion. That is, before engaging the first reference plane with the engaging surface of the shaft member, the insertion portion with a smaller diameter is inserted into the concave portion. Thereby, the movement range in the rotational direction of the shaft member is restricted within the range where the insertion portion can relatively move within the concave portion, and approximate positioning in the rotational direction of the shaft member can be achieved. That is, the first reference plane can be engaged with the engaging surface of the shaft member in a state where the positional deviation in the rotational direction between the insertion portion and the concave portion is small, and the two can be engaged smoothly. Thereby, the frictional force generated between the first reference plane and the engaging surface can be reduced, and wear of both can be suppressed. Therefore, the positioning portion can accurately position the shaft member at the reference phase over a long period. Also, by making the diameter of the insertion portion smaller than the diameter of the portion where the first reference plane is provided, the insertion portion can be easily inserted into the concave portion.

[0011] The internal combustion engine may be configured such that the engaging surface is provided on both sides in the rotational direction of the shaft member, and is an inclined surface that inclines in the direction in which the diameter of the concave portion decreases from the outer side to the inner side in the radial direction of the shaft member, and the first reference plane is provided at positions corresponding to both sides in the rotational direction of the shaft member, and is an inclined surface that inclines in the direction in which the positioning portion decreases in diameter toward the tip side on the shaft member side of the positioning portion. By engaging the shaft member and the positioning portion with the inclined surfaces, the shaft member can be accurately positioned at the reference phase.

[0012] The internal combustion engine is the internal combustion engine according to claim 1, having each valve operating device corresponding to each cylinder, wherein a single said shaft member rotates, or a plurality of said shaft members rotate integrally, to transmit a driving force to the valve operating device of each cylinder, and the positioning mechanism can be an internal combustion engine that engages at a position corresponding to the cylinder closest to the drive source on the shaft member. Thereby, the adverse effects caused by the torsion of the shaft member can be prevented.

[0013] The internal combustion engine can have a bearing that rotatably holds the shaft member, and the positioning mechanism can be supported by the bearing. Since the positional accuracy between the bearing and the shaft member is high, by providing the positioning mechanism on the bearing, the positioning mechanism can accurately position the shaft member at the reference phase.

[0014] The present invention also relates to a method for determining the phase in the rotational direction of a shaft member, characterized in that a shaft member rotatably driven by a drive source and a positioning mechanism are engaged in the rotational direction of the shaft member, thereby positioning the shaft member at a reference phase that serves as a reference for displacement in its rotational direction. Thereby, the shaft member can be accurately positioned at the reference phase.

Effects of the Invention

[0015] According to the present invention, the shaft member can be accurately positioned at the reference phase.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Best Mode for Carrying Out the Invention

[0017] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each figure, the same or corresponding parts are denoted by the same reference numerals, and the redundant description thereof will be simplified or omitted as appropriate.

[0018] FIG. 1 shows a valve actuating device 1 as a shaft device according to an embodiment of the present invention. The valve actuating device 1 is provided in an engine 100 as an internal combustion engine, and opens and closes an intake valve or an exhaust valve provided in the engine 100.

[0019] As shown in FIG. 1, the valve actuating device 1 has a swing arm 2 and a push rod 10. The swing arm 2 is rotatably provided about an eccentric shaft 3. The push rod 10 is attached to a tray 2c provided at one end 2a of the swing arm 2. A roller 4 provided on one end 2a side of the swing arm 2 abuts against a cam 5. By changing the surface of the cam 5 that rotates and abuts against the roller 4, the swing arm 2 rotates about the rotation center 3a of the eccentric shaft 3, and the one end 2a side swings up and down. Thereby, the push rod 10 connected to one end 2a of the swing arm 2 moves up and down, and the corresponding valve can be opened and closed.

[0020] On the other end 2a side of the swing arm 2, there is a rotatable rotary shaft 6 as a shaft member. The rotation center 3a of the eccentric shaft 3 of the swing arm 2 is located at a position deviated from the rotation center of the rotary shaft 6. By the rotation of the rotary shaft 6, as shown in FIG. 2, the swing arm 2 moves in the left - right direction of FIG. 2 along the outer peripheral surface of the cam 5 (for example, moves from the solid line position to the dotted line position in FIG. 2). Thereby, the position of the cam 5 with which the roller 4 abuts changes, and the timing at which the swing arm 2 swings up and down changes. Thereby, the timing at which the push rod 10 moves up and down changes, and the opening and closing timing of the valve can be changed.

[0021] As shown in FIG. 3, the rotating shafts 6 provided in the valve operating devices 1 of the respective cylinders are connected via a connecting member. In the present embodiment, only the swing arm 2 on the intake side rotates due to the rotation of the rotating shaft 6, and only the opening and closing timing of the intake-side valve is changed. However, the opening and closing timing of the exhaust-side valve may be changed. The driving force is transmitted to these rotating shafts 6 by an actuator 7 as a driving source, so that these rotating shafts 6 rotate integrally. The control unit of the valve operating device 1 recognizes the current rotational phase of the rotating shaft 6. Therefore, the control unit of the valve operating device 1 can operate the actuator 7 according to the load required for the engine or the like to rotate the rotating shaft 6 and change the opening and closing timing of the valve to a desired timing.

[0022] FIG. 4 shows an example of changing the opening and closing timing of the intake valve by moving the swing arm 2 as an example of changing the opening and closing timing of the valve. The horizontal axis in FIG. 4 represents the rotation angle of the cam 5, and the vertical axis represents the opening amount of the intake valve. The solid line in FIG. 4 shows the case of the opening and closing timing in the initial state, and the dashed-dotted line in FIG. 4 shows the case where the opening and closing timing is shifted. The cam 5 is arranged at the top dead center at 0 degrees in FIG. 4.

[0023] As shown in FIG. 4, the opening timing of the valve with respect to the rotation angle of the cam 5 is changed by β before and after the change. That is, before the change, the valve starts to open when the cam 5 reaches the angle α, while after the change, it starts to open from the angle α - β, which is β earlier than that. The angle θ indicates the top dead center of the cam 5. In this way, the opening and closing timing of the valve can be changed by the rotation of the rotating shaft 6.

[0024] In such a valve operating device 1, if the power supply to the valve operating device 1 suddenly stops due to a power failure or the like, the control unit of the valve operating device 1 loses sight of the current rotational phase of the rotating shaft 6, that is, the current horizontal position of the swing arm 2. Therefore, the opening and closing timing of the valve cannot be changed to a desired timing on the device side as it is.

[0025] FIG. 5 is a view seen in the direction of arrow A in FIG. 3, and shows a state in which the rotational phase of the rotary shaft 6 is positioned at the reference phase by the positioning mechanism 20.

[0026] As shown in FIG. 5, the rotary shaft 6 is provided so as to penetrate through the intake-side swing arm 2A and the exhaust-side swing arm 2B. Bearings 8A and 8B are provided adjacent to the outer sides in the axial direction of the swing arms 2A and 2B, respectively.

[0027] In the present embodiment, the positioning mechanism 20 can be attached to and detached from the bearings 8A and 8B. The positioning mechanism 20 includes a support member 21 bridged over the bearings 8A and 8B, and a bolt 22 provided so as to be able to advance and retreat in a hole portion of the support member 21 and serving as a positioning portion. The support member 21 is supported by the bearings 8A and 8B by screwing both ends thereof to the bearings 8A and 8B, respectively. An insertion hole 6a serving as a recess into which the bolt 22 can be inserted is provided at a predetermined position in the circumferential direction on the central side in the axial direction of the rotary shaft 6. The insertion hole 6a is a recess that is recessed inward in the radial direction of the rotary shaft 6. The radial direction of the rotary shaft 6 means each direction toward the center side of the rotary shaft 6 and the opposite direction on a plane orthogonal to the axial direction of the rotary shaft 6.

[0028] The cross-section on the central side of the rotary shaft 6 provided with the insertion hole 6a is rectangular, and the insertion hole 6a is provided on one surface thereof. When aligning the phases of the rotary shaft 6, first, the support member 21 is screwed to the bearings 8A and 8B. Then, a wrench is applied to the central side of the rotary shaft 6 to rotate the rotary shaft 6 so that the insertion hole 6a faces the bolt 22. In the present embodiment, a wrench is applied to and rotates a rotary shaft 6 different from the rotary shaft 6 to which the positioning mechanism 20 is attached. Then, the bolt 22 is projected toward the rotary shaft 6 side and inserted into the insertion hole 6a. Thereby, the rotary shaft 6 can be arranged at a reference phase that serves as a reference for displacement in the rotational direction. As described above, by positioning the rotary shaft 6 by the positioning mechanism 20, the rotary shaft 6 can be mechanically positioned at the reference phase. In this state, the control unit of the valve operating device 1 is made to recognize that the rotary shaft 6 is arranged at the reference phase. As described above, the control unit of the valve operating device 1 can recognize the current rotational phase of the rotary shaft 6. However, the position where the insertion hole 6a is provided and the shape of the rotary shaft 6 are not limited to the present embodiment.

[0029] Next, in the valve operating device of the present embodiment, a method of phase determination for inserting the bolt 22 into the insertion hole 6a to position the rotary shaft 6 at the reference phase will be described in detail with reference to FIGS. 6(a) to 6(d). FIGS. 6(a) to 6(d) are enlarged views of the portion of the insertion hole 6a and the tip of the bolt 22, and show how the tip of the bolt 22 is inserted into the insertion hole 6a of the rotary shaft 6. Note that in FIG. 6, the double-headed arrow C direction shown in FIG. 6(a) is the rotational direction of the rotary shaft 6, and FIGS. 6(a) to 6(d) are illustrated from a direction different from that of FIG. 5.

[0030] As shown in FIG. 6(a), the rotary shaft 6 has an engagement surface 6a1, which is a surface forming the insertion hole 6a, on the entrance side of the insertion hole 6a. The engagement surface 6a1 is an inclined surface that is inclined in the direction in which the insertion hole 6a decreases in diameter from the entrance side to the back side of the insertion hole 6a, that is, from the bottom to the top in FIG. 6(a). In other words, it is an inclined surface that is inclined in the direction in which the insertion hole 6a decreases in diameter from the outer side to the inner side in the radial direction of the rotary shaft 6.

[0031] The bolt 22 has a first reference surface 22a that engages with the engagement surface 6a1. The first reference surface 22a is an inclined surface that slopes in the direction in which the diameter of the bolt 22 decreases, toward the tip side of the side where the bolt 22 is inserted with respect to the rotation axis 6, that is, from the bottom to the top in FIG. 6(a). In other words, the first reference surface 22a is an inclined surface having a shape corresponding to the engagement surface 6a1 of the rotation axis 6. When the first reference surface 22a engages with the engagement surface 6a1, the rotation axis 6 is positioned in the reference phase (see FIG. 6(d)). The bolt 22 also has an insertion portion 22c on the tip side closer to the rotation axis 6 than the first reference surface 22a. The insertion portion 22c has a diameter B2 that is smaller than the diameter B1 of the root portion of the first reference surface 22a and the diameter B3 of the insertion hole 6a.

[0032] By providing the insertion portion 22c with a smaller diameter on the tip side of the first reference surface 22a of the bolt 22, the first reference surface 22a can be smoothly engaged with the engagement surface 6a1, and wear of the first reference surface 22a and the engagement surface 6a1 can be suppressed. That is, before engaging the engagement surface 6a1 and the first reference surface 22a, by inserting the insertion portion 22c into the insertion hole 6a, the bolt 22 can be roughly positioned in the rotational direction of the rotation axis 6 with respect to the insertion hole 6a (see FIG. 6(c)). In particular, in this embodiment, the diameter B2 of the insertion portion 22c is slightly smaller than the diameter B3 of the insertion hole 6a, and is positioned with a play corresponding to this dimensional difference in the rotational direction of the rotation axis 6. Then, by engaging the first reference surface 22a with the engagement surface 6a1 in a state where the positional deviation between the bolt 22 and the insertion hole 6a is small, the frictional force generated between the first reference surface 22a and the engagement surface 6a1 can be reduced, and the two can be smoothly engaged. As a result, wear of the first reference surface 22a and the engagement surface 6a1 can be suppressed, and the positioning accuracy of the bolt 22 with respect to the rotation axis 6 over a long period, that is, the accuracy of positioning the rotation axis 6 in the reference phase can be improved. Further, since the diameter B2 of the insertion portion 22c is smaller than the diameter B1 of the first reference surface 22a and the diameter B3 of the insertion hole 6a, the operation of inserting the insertion portion 22c into the insertion hole 6a itself becomes easier. That is, there is a dimensional difference between the insertion hole 6a and the insertion portion 22c that is larger than the difference between the portion of the bolt 22 having the first reference surface 22a and the portion of the engagement surface 6a1 of the insertion hole 6a, and the insertion operation of the insertion portion 22c into the insertion hole 6a becomes easier by this dimensional difference.

[0033] In particular, in the present embodiment, a second reference plane 22b is provided at the tip of the insertion portion 22c. The second reference plane 22b is an inclined plane having the same inclination as the first reference plane 22a, and is inclined in the direction in which the tip of the bolt 22 is reduced in diameter, that is, from the bottom to the top in Fig. 6(a), that is, in the direction in which the tip of the bolt 22 is inserted with respect to the rotation axis 6. The first reference plane 22a and the second reference plane 22b of the present embodiment are provided circumferentially.

[0034] The second reference plane 22b is a guide surface for guiding the bolt 22 when the bolt 22 is inserted into the insertion hole 6a. By providing the second reference plane 22b in the insertion portion 22c, the insertion operation of the insertion portion 22c into the insertion hole 6a can be performed smoothly. That is, as shown in Fig. 6(b), even when the insertion operation is performed with the bolt 22 being misaligned with respect to the insertion hole 6a, the second reference plane 22b of the bolt 22 abuts against the engaging surface 6a1 on the rotation axis 6 side and moves along the engaging surface 6a1 (see the arrow in Fig. 6(b)), so that the bolt 22 is guided in the direction of being inserted into the insertion hole 6a. In particular, by providing the engaging surface 6a1 and the first reference plane 22a on both sides in the rotation direction of the rotation axis 6, the bolt 22 can be guided so as to move relatively toward the insertion hole 6a regardless of whether the bolt 22 is displaced in either direction of the rotation direction with respect to the insertion hole 6a. Further, this can reduce the frictional force generated between the insertion portion 22c and the engaging surface 6a1 and suppress the wear of the engaging surface 6a1.

[0035] Then, as shown in Fig. 6(c), the bolt 22 is guided by the second reference plane 22b and the insertion portion 22c is inserted into the insertion hole 6a.

[0036] Furthermore, by inserting the bolt 22 into the insertion hole 6a, as shown in Fig. 6(d), the first reference plane 22a of the bolt 22 engages with the engaging surface 6a1.

[0037] By engaging the first reference plane 22a with the engaging surface 6a1, the rotation axis 6 can be reliably positioned at the reference phase. Thereby, it becomes possible to align the actual rotation phase of the rotation axis 6 with the phase recognized by the device side.

[0038] The rotating shafts 6 of the valve actuating devices 1 provided in each cylinder rotate integrally. Therefore, the insertion hole 6a for inserting the bolt 22 of the positioning mechanism 20 may be provided in at least any one of the rotating shafts 6. In the present embodiment, the insertion hole 6a is provided in the rotating shaft 6 on the side closest to the actuator 7 (see FIG. 1), and positioning by the positioning mechanism 20 is performed on this rotating shaft 6. Note that a single rotating shaft 6 may be provided across each cylinder, and a driving force may be transmitted to the swing arms 2 of each cylinder by this rotating shaft 6 to move the swing arms 2 along the outer peripheral surface of the cam. Even in this case, the insertion hole 6a for inserting the bolt 22 can be provided at any position in the axial direction of the rotating shaft 6, for example, at a position corresponding to the valve actuating device 1 on the actuator 7 side in the axial direction of the rotating shaft 6.

[0039] Also, by supporting the positioning mechanism 20 by the bearings 8A and 8B, the positioning accuracy of the positioning mechanism 20 with respect to the rotating shaft 6 can be improved. That is, the position accuracy of the bearings 8A and 8B with respect to the rotating shaft 6 they support is higher than that of other members in the valve actuating device 1. Therefore, by providing the positioning mechanism 20 on the bearings 8A and 8B as in the present embodiment, the rotating shaft 6 can be positioned at the reference phase with good position accuracy. However, the positioning mechanism 20 may be provided on other members.

[0040] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

[0041] In the above embodiment, a configuration is shown in which the positioning portion of the positioning mechanism is inserted radially into the concave portion provided in the shaft member and engaged in the rotational direction of the shaft member. However, for example, a configuration in which the positioning portion is inserted axially into the concave portion provided in the shaft member and engaged in the rotational direction of the shaft member may be used. Also, it is not necessarily the case that the positioning portion is inserted into the concave portion of the shaft member.

[0042] In the above-described embodiment, the first reference plane 22a and the engagement surface 6a1 have a frustum-of-a-cone shape with a constant inclination angle in the circumferential direction. However, for example, they may have a frustum-of-a-square-pyramid shape. Further, in the above-described embodiment, the first reference plane 22a and the engagement surface 6a1 are provided circumferentially. However, the engagement surface 6a1 may be provided only on both sides in the rotation direction of the rotation shaft 6, and the first reference plane 22a may be provided at positions corresponding to both sides in the rotation direction of the rotation shaft 6, that is, at positions corresponding to the respective engagement surfaces 6a1, and a configuration may be adopted in which they engage only on both sides in the rotation direction. Furthermore, the first reference plane 22a and the engagement surface 6a1 may be provided only on one side in the rotation direction, and a configuration may be adopted in which they engage only on one side in the rotation direction. In addition, the configurations of the concave portion and the positioning portion of the present invention are not limited to the above-described embodiment. For example, as the positioning portion shown in FIG. 7, the bolt 23 has only the surface 23a as an inclined surface. The surface 23a functions as a guide surface, for example. Then, a vertical surface 23b continuous with the surface 23a engages with a vertical surface 6a2 (see FIG. 6(a)) forming the insertion hole 6a, and the bolt 23 is fitted into the insertion hole 6a, so that the rotation shaft 6 can be positioned in the reference phase. In this case, the radial gap between the two is set smaller than that in the embodiment shown in FIG. 6 so that the bolt 23 is fitted into the insertion hole 6a. Further, a positioning portion that does not have a guide surface such as the surface 22b in FIG. 6 or the surface 23a in FIG. 7 may be used. Further, a configuration may be adopted in which the surface 23a in FIG. 7 engages with the surface 6a1 of the insertion hole 6a. Further, in the embodiment shown in FIG. 8, a concave portion 6b is provided in the rotation shaft 6. An engagement surface 6b1 facing the concave portion 6b and a first reference plane 24a of the positioning portion 24 engage with each other in the rotation direction of the rotation shaft 6. Thereby, the rotation shaft 6 is positioned in the reference phase.

[0043] In the above-described embodiment, a bolt has been described as the positioning portion of the present invention. However, a positioning portion that protrudes toward the shaft member side by the biasing force of a spring and engages with the shaft member, or conversely, a positioning portion that a worker protrudes toward the shaft member side against the biasing force of a spring and engages with the shaft member may be used. Further, in addition, as long as the configuration can position the shaft member, an appropriate configuration of the positioning portion can be adopted.

[0044] In the above-described embodiment, the positioning mechanism 20 is removed when the valve operating device 1 is used, but it may be left attached. By making the positioning mechanism 20 detachable, it is possible to prevent interference with other members such as interference with a cover member that covers the swing arm 2 or the like, and to prevent any hindrance to the use of the valve operating device 1.

[0045] In the above-described embodiment, the case where the shaft member is manually rotated and positioned at the reference phase by the positioning portion is shown, but the present invention is not limited to this. For example, after the power supply is restored, the shaft member may be rotated by the driving force of the drive source and positioned by the positioning mechanism, so that the shaft member is arranged at the reference phase.

Explanation of Reference Numerals

[0046] 1 Valve operating device (shaft device) 2 Swing arm 6 Rotating shaft (shaft member) 6a Insertion hole (recess) 6a1 Engaging surface 7 Actuator (drive source) 8A, 8B Bearings 20 Positioning mechanism 22 Bolt (positioning portion) 22a First reference surface 22b Second reference surface 22c Insertion portion 100 Engine (internal combustion engine)

Claims

1. A drive source, a shaft member that is rotationally driven by the drive source, and a positioning mechanism that positions the shaft member at a reference phase that serves as a reference for displacement in the rotational direction by engaging with the shaft member in its rotational direction, wherein the internal combustion engine is characterized by comprising these components.

2. The shaft member has a recess that is recessed in its radial direction and an engagement surface that forms the recess, the positioning mechanism has a positioning portion, and the positioning portion engages with the engagement surface in the rotational direction of the shaft member and has a first reference surface that positions the shaft member at the reference phase. The internal combustion engine according to claim 1.

3. The positioning portion has an insertion portion that is smaller in diameter than the portion of the positioning portion where the first reference surface is provided on the tip side closer to the shaft member than the first reference surface and is inserted into the recess. The internal combustion engine according to claim 2.

4. The engagement surface is provided on both sides in the rotational direction of the shaft member and is an inclined surface that is inclined in a direction in which the recess contracts in diameter from the outside to the inside in the radial direction of the shaft member, and the first reference surface is provided at positions corresponding to both sides in the rotational direction of the shaft member and is an inclined surface that is inclined in a direction in which the positioning portion contracts in diameter toward the tip side closer to the shaft member of the positioning portion. The internal combustion engine according to claim 2.

5. The internal combustion engine according to claim 1, having each valve operating device corresponding to each cylinder, wherein a single said shaft member rotates or a plurality of said shaft members rotate integrally to transmit a driving force to the valve operating devices of each cylinder, and the positioning mechanism engages at a position corresponding to the cylinder closest to the drive source on the shaft member. The internal combustion engine according to claim 1.

6. having a bearing that rotatably holds the shaft member, and the positioning mechanism is supported by the bearing. The internal combustion engine according to claim 1.

7. A method for determining the phase in the rotational direction of a shaft member, characterized in that the shaft member is positioned at a reference phase that serves as a reference for displacement in the rotational direction by engaging a drive source-driven shaft member and a positioning mechanism in the rotational direction of the shaft member.

Images