JP5920624B2 - Cam shift device - Google Patents

Description

  The present invention relates to a cam shift device capable of changing the opening / closing timing of a valve.

2. Description of the Related Art Conventionally, cam shift devices that can change the opening / closing timing of an intake valve or an exhaust valve of an engine are known.
In the cam shift device described in Patent Document 1, a plurality of cam pieces are fixed to a cam shaft. The cam piece includes a first cam portion and a second cam portion that are adjacent in the axial direction. The first cam portion has a cylindrical base and a nose protruding in the radial direction from the base. A 2nd cam part consists only of a cylindrical base. A rocker arm that drives the intake valve or the exhaust valve is in sliding contact with the outer wall of the cam piece in the radial direction. The rocker arm is biased toward the cam piece by a valve spring. The rocker arm lifts against the biasing force of the valve spring when it makes sliding contact with the nose of the first cam portion.
In the first embodiment of Patent Document 1, when an actuator provided on one of the camshafts in the axial direction moves the camshaft in the axial direction, the plurality of cam pieces fixed to the camshaft are in the axial direction with respect to the rocker arm. Move relative. This changes the opening / closing timing of the intake valve or exhaust valve driven by the rocker arm.

JP 2011-144780 A

However, the four cam pieces generally used in a four-cylinder engine each have a nose with a phase difference of 90 ° in the rotational direction. Therefore, in Patent Document 1, the actuator moves the camshaft in the axial direction in a state where any one of the four cam pieces is in sliding contact with the rocker arm. In this case, since the urging force of the valve spring acts on the cam piece from the lifted rocker arm, there is a concern that the driving force of the actuator increases.
Further, if the camshaft is moved in the axial direction while the rocker arm is lifted, the rocker arm may be displaced in the axial direction.
The present invention has been made in view of the above problems, and an object thereof is to provide a cam shift device capable of reducing the driving force of an actuator.

According to a first aspect of the present invention, in the cam shift device in which the first cam portion and the second cam portion are provided on the camshaft, the first guide and the second guide that slide in the axial direction together with the first cam portion and the second cam portion slide. The actuator is characterized in that the actuator moves in the axial direction on the arm that can be contacted. The first inclined surface of the first guide and the second inclined surface of the second guide are axial when the sliding member and the first nose are in sliding contact with the outer periphery of the first cam portion and the second cam portion. It is provided in a range that does not overlap with the arm as viewed from the top. The first guide is provided on one side of the first cam portion in the axial direction, and the second guide is provided on the other side of the second cam portion in the axial direction.
In the second aspect of the invention, the arm portion is provided with the first arm portion (41) capable of sliding contact with the axial end surface provided with the first inclined surface of the first guide, and the second inclined surface of the second guide. And a second arm portion (42) slidably contactable with the axial end surface.

  As a result, when the actuator moves in the axial direction on the arm portion, the first nose and the sliding contact member are in sliding contact with the cam piece including the first cam portion, the second cam portion, the first guide, and the second guide. When not, move in the axial direction. On the other hand, even if the actuator moves the arm portion in the axial direction, the cam piece does not move in the axial direction when the first nose and the sliding contact member are in sliding contact. Therefore, since the actuator moves the shifter shaft in a state where the load applied to the first cam portion from the sliding contact member is reduced, the driving force of the actuator can be reduced.

It is a principal part enlarged view of the cam shift apparatus by 1st Embodiment of this invention. It is sectional drawing of the II-II line of FIG. It is sectional drawing of the III-III line of FIG. It is explanatory drawing which shows operation | movement of the cam shift apparatus by 1st Embodiment of this invention. It is explanatory drawing which shows operation | movement of the cam shift apparatus by 1st Embodiment of this invention. It is explanatory drawing which shows operation | movement of the cam shift apparatus by 1st Embodiment of this invention. It is explanatory drawing which shows operation | movement of the cam shift apparatus by 1st Embodiment of this invention. 1 is an overall view of a cam shift device according to a first embodiment of the present invention. It is a time chart which shows operation | movement of the cam shift apparatus by 1st Embodiment of this invention. It is a time chart which shows operation | movement of the cam shift apparatus by 2nd Embodiment of this invention. It is a block diagram of the cam shift apparatus by 3rd Embodiment of this invention. It is a block diagram of the cam shift apparatus by 4th Embodiment of this invention.

Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
A cam shift device according to a first embodiment of the present invention is shown in FIGS. The cam shift device 10 according to the present embodiment drives, for example, an intake valve of a four-cylinder engine, and changes the opening / closing timing of the intake valve.
FIGS. 1-7 has shown the principal part enlarged view of the cam shift apparatus 10 which opens and closes two intake valves provided in one cylinder of a 4-cylinder engine. The timing at which the rocker arm 11 that opens and closes one intake valve 15 is lifted by the cam shift device 10 is changed. The rocker arm 12 that opens and closes the other intake valve lifts at a constant cycle. The rocker arm of the present embodiment corresponds to a “sliding contact member” recited in the claims.

As shown in FIGS. 1 to 3, the cam shift device 10 includes a cam shaft 13, a plurality of cam pieces 20 and 21, rocker arms 11 and 12, a shifter shaft 40, arm portions 41 and 42, and an actuator 43.
The camshaft 13 is connected to a crankshaft of an engine (not shown) by a gear and a chain, and rotates in conjunction with the crankshaft.

One cam piece 20 is provided such that it cannot rotate relative to the cam shaft 13 and can reciprocate in the axial direction, and drives one rocker arm 11 whose lift timing can be changed.
The other cam piece 21 is fixed so that it cannot rotate relative to the camshaft 13 and cannot reciprocate in the axial direction, and drives the other rocker arm 12 that lifts at a constant cycle.
The rocker arms 11 and 12 are biased toward the cam piece by a valve spring 14. When the rocker arms 11 and 12 are in sliding contact with the noses 24 and 27 of the cam pieces 20 and 21, the rocker arms 11 and 12 are lifted against the urging force of the valve spring 14 to open the intake valve 15.

  One cam piece 20 includes a first cam portion 22, a second cam portion 25, a first guide 31, a second guide 36, and the like. A spline groove 131 extending in the axial direction is provided on the outer wall of the camshaft 13 at a position where one cam piece 20 is provided. A spline 200 corresponding to the spline groove 131 of the camshaft 13 is provided on the inner wall in the radial inner direction of the cam piece 20. Therefore, the cam piece 20 includes the first cam portion 22, the second cam portion 25, the first guide 31, and the second guide 36 that are integrally reciprocable in the axial direction and that is not rotatable relative to the camshaft 13. is there.

The first cam portion 22 has a cylindrical first base 23 and a first nose 24 protruding from the first base 23 in one of the radial directions.
The second cam portion 25 includes a cylindrical second base 26 having the same diameter as the first base 23 and a second nose 27 protruding from the second base 26 in one radial direction. The first nose 24 and the second nose 27 are provided in different phases in the rotation direction.

The first guide 31 is provided on one axial direction of the first cam portion 22 and is connected to the first cam portion 22 by the connecting portion 28. The first guide 31 has a first inclined surface 32, a first thick part 33, and a first thin part 34.
The first inclined surface 32 is inclined from one axial direction to the other in the forward direction. The first thick portion 33 is provided perpendicular to the rotation axis from the end of the first inclined surface 32 at the rear in the rotation direction. The first thin portion 34 is provided perpendicularly to the rotation axis from the front end portion of the first inclined surface 32 in the rotation direction.
When the first nose 24 and the rocker arm 11 are in sliding contact, and when the second nose 27 and the rocker arm 11 are in sliding contact, the first inclined surface 32 and the first thick portion 33 are arms viewed from the axial direction. It is provided in a range that does not overlap the portions 41 and 42.
On the other hand, when the first nose 24 and the rocker arm 11 are in sliding contact with each other and when the second nose 27 and the rocker arm 11 are in sliding contact with each other, the first thin portion 34 is It is provided in the overlapping range.

  The second guide 36 is provided on the other axial direction of the second cam portion 25 and is connected to the second cam portion 25 by the connecting portion 28. The second guide 36 has a second inclined surface 37, a second thick part 38, and a second thin part 39. The second guide 36 is formed symmetrically with the first guide 31 with respect to a virtual plane perpendicular to the rotation axis of the camshaft 13.

The shifter shaft 40, the arm portions 41 and 42, and the actuator 43 constitute a shifter 45 that moves the cam piece 20 in the axial direction.
The shifter shaft 40 extends substantially parallel to the camshaft 13 and can reciprocate in the axial direction. A spring 46 provided on one side of the shifter shaft 40 in the axial direction biases the shifter shaft 40 toward the actuator 43.
The first arm portion 41 and the second arm portion 42 are each fixed to the shifter shaft 40 and can reciprocate in the axial direction together with the shifter shaft 40. The first arm portion 41 can be slidably contacted with the axial end surface of the first guide 31 on which the first inclined surface 32 is provided, and the second arm portion 42 is provided with the second inclined surface 37 etc. of the second guide 36. It can be slidably contacted with the provided axial end face.
The actuator 43 can reciprocate the shifter shaft 40 in the axial direction within the movement range of one cam piece 20. The actuator 43 is driven by a command from an engine electronic control unit (ECU) (not shown).

Next, the operation of the cam shift device 10 will be described.
1 to 7, the camshaft 13 is assumed to rotate in the direction of arrow A.
In the state of FIG. 1, the first thick portion 33 of the first guide 31 and the first arm portion 41 of the shifter 45 are in sliding contact. When the actuator 43 is energized in this state and the actuator 43 moves the shifter shaft 40 to the left in FIG. 1, the cam piece 20 moves in the axial direction of the camshaft 13 along the spline groove 131 as shown in FIG. 4. . At this time, the rocker arm 11 moves from the second base 26 to the first base 23. Therefore, the urging force of the valve spring 14 acting on the cam piece 20 is small as compared to the movement of the cam piece 20 with the rocker arm lifted.

  Next, in the state of FIG. 5, the second nose 27 of the second cam portion 25 and the rocker arm 11 are in sliding contact, and the rocker arm 11 is lifted. At this time, the first arm portion 41 and the second arm portion 42 of the shifter 45 are in a position overlapping the first thin portion 34 and the second thin portion 39 when viewed from the axial direction. When the actuator 43 moves the shifter shaft 40 to the left in FIG. 5 in this state, as shown in FIG. 6, the first arm portion 41 and the first thin portion 34 are in sliding contact with each other without moving the cam piece 20. If the camshaft 13 rotates in the direction of arrow A and the rocker arm 11 is lifted and the second base 26 of the second cam portion 25 and the rocker arm 11 are in sliding contact with each other, the first arm portion 41 and the first inclination The surface 32 is in sliding contact. Thereby, the torque of the camshaft 13 is converted into a force for moving the cam piece 20 in the axial direction. Therefore, as shown in FIG. 7, the cam piece 20 moves along the spline groove 131 in the axial direction of the camshaft 13, and the rocker arm 11 moves from the second base 26 to the first base 23.

  When the energization of the actuator 43 is stopped, the shifter shaft 40 moves to the right in FIG. In this case, the axial end surface provided with the second inclined surface 37 and the like of the second guide 36 and the second arm portion 42 are in sliding contact with the operation similar to the operation shown in FIGS. Moves to the right in FIG.

  Next, an overall view of the cam shift device 10 is shown in FIG. The camshaft 13 is provided with a plurality of cam pieces corresponding to a four-cylinder engine (not shown). The first cam piece 101 and the second cam piece 102 correspond to the No. 1 cylinder of the engine (not shown), the third cam piece 103 and the fourth cam piece 104 correspond to the No. 2 cylinder (not shown), and the fifth cam piece 105 and the sixth cam piece 106 The seventh cam piece 107 and the eighth cam piece 108 correspond to a No. 4 cylinder (not shown). In FIG. 8, the cylinders No. 1 to No. 4 are indicated by numerals 1 to 4 in the circles.

  The first cam piece 101, the third cam piece 103, the fifth cam piece 105, and the seventh cam piece 107 are provided such that the nose position is changed in phase by 90 ° in the rotation direction. In addition, the second cam piece 102, the fourth cam piece 104, the sixth cam piece 106, and the eighth cam piece 108 are provided so that the nose positions change in phase by 90 ° in the rotational direction. The second cam piece 102, the fourth cam piece 104, the sixth cam piece 106, and the eighth cam piece 108 can individually reciprocate in the axial direction along the spline groove 131.

Next, the operation of the cam shift device 10 will be described with reference to the time chart of FIG.
FIG. 9 shows the operation of each cam piece when the crankshaft rotates by 1440 °. When the crankshaft rotates 1440 °, the camshaft 13 rotates 720 °.
In FIG. 9, the operations of the second cam piece 102, the sixth cam piece 106, the fourth cam piece 104, and the eighth cam piece 108 corresponding to the cylinders No. 1, No. 3, No. 2, and No. 4 are described from the top. A cam lift is shown above the solid line of each cylinder No, and a guide lift is shown below the solid line of each cylinder No.
The cam lift means that the first nose 24 or the second nose 27 of the cam piece lifts the rocker arm 11. Further, the guide lift means an axial distance from the first thin portion 34 to the first inclined surface 32 or the first thick portion 33 at a position overlapping the first arm portion 41 when viewed from the axial direction.

The actuator 43 moves the shifter shaft 40 during a crank phase d1 to d2 indicated by a one-dot chain line.
In the crank phases d1 to d2, the second cam piece 102 corresponding to the No. 1 cylinder and the sixth cam piece 106 corresponding to the No. 3 cylinder are both the first thick portion 33 and the first arm portion 41 of the first guide 31. Is in sliding contact. Therefore, the second cam piece 102 corresponding to the No. 1 cylinder and the sixth cam piece 106 corresponding to the No. 3 cylinder move in the axial direction during the crank phases d1 to d2.

In contrast, in the crank phases d1 to d2, the fourth cam piece 104 corresponding to the No. 2 cylinder and the eighth cam piece 108 corresponding to the No. 4 cylinder are both the first thin portion of the first guide 31 as viewed from the axial direction. 34 and the first arm portion 41 are in a position where they overlap. For this reason, the fourth cam piece 104 corresponding to the No. 2 cylinder has the first inclined surface 32 of the first guide 31 and the first arm portion 41 between the crank phases d2 to d4 after the operation of the shifter 45 ends. Moves in the axial direction when overlapping when viewed from the direction. The eighth cam piece 108 corresponding to the No. 4 cylinder has the first inclined surface 32 and the first arm portion 41 of the first guide 31 in the axial direction between the crank phases d3 to d5 after the operation of the shifter 45 is completed. Moves in the axial direction when overlapping when viewed from above.
As a result, the cam shift device 10 can individually move the plurality of cam pieces 102, 104, 106, 108 having different nose phases in the rotation direction by one actuator 43.

  In addition, the actuator 43 is when the 1st arm part 41 and the 1st thick part 33 overlap, or when the 1st arm part 41 and the 1st thin part 34 overlap seeing from the axial direction of the camshaft 13. It is preferable to move the shifter shaft 40 in a straight line. This is to prevent the first arm portion 41 and the first inclined surface 32 from coming into contact with each other while the shifter shaft 40 is moving, or the second arm portion 42 and the second inclined surface 37 from coming into contact with each other.

In the present embodiment, the following effects are obtained.
(1) In the present embodiment, the first inclined surface 32 of the first guide 31 and the second inclined surface 37 of the second guide 36 are formed when the rocker arm 11 and the first nose 24 are in sliding contact with each other, and the rocker arm 11. And the second nose 27 slidably contact with each other, the first arm portion 41 and the second arm portion 42 are provided so as not to overlap with each other when viewed in the axial direction.
Thus, when the actuator 43 moves the shifter shaft 40 in the axial direction, the cam piece 20 moves in the axial direction when the first nose 24 and the rocker arm 11 are not in sliding contact. On the other hand, when the first nose 24 and the rocker arm 11 are in sliding contact, the cam piece 20 does not move in the axial direction. Therefore, since the actuator 43 moves the shifter shaft 40 in a state where the urging force of the valve spring 14 acting on the cam piece 20 from the rocker arm 11 is reduced, the driving force of the actuator 43 can be reduced.

(2) In the present embodiment, when the first nose 24 and the rocker arm 11 are in sliding contact, and when the rocker arm 11 and the second nose 27 are in sliding contact, the first thick portion 33 and the second thick portion. 38 is provided in a range that does not overlap with the arm portions 41 and 42 when viewed in the axial direction. Thereby, when the actuator 43 moves the shifter shaft 40, the first thick portion 33 and the first arm portion 41 are in sliding contact, or the second thick portion 38 and the second arm portion 42 are in sliding contact. In this state, the cam piece 20 can be moved.

(3) In the present embodiment, the first guide 31 is provided on one side of the first cam portion 22 in the axial direction, and the second guide 36 is provided on the other side of the second cam portion 25 in the axial direction. Thereby, the 1st cam part 22, the 2nd cam part 25, the 1st guide 31, and the 2nd guide 36 are comprised integrally, and while reducing the physique of the cam piece 20, a structure can be simplified. .

(4) In the present embodiment, the arm portions 41, 42 are in contact with the first arm portion 41 slidably contacted with the axial end surface provided with the first inclined surface 32 of the first guide 31, and the second guide 36. And the second arm portion 42 slidably brought into contact with the axial end surface provided with the second inclined surface 37 and the like. Thereby, durability of the shifter 45 can be improved by reducing the load applied to one arm part.

(5) In the present embodiment, the plurality of cam pieces 20 are provided so as to be reciprocally movable in the axial direction of the camshaft 13. As a result, when the nose positions of the cam portions included in the plurality of cam pieces 20 are different in the rotation direction, the plurality of cam pieces can be individually moved by one actuator 43.

(Second Embodiment)
A second embodiment of the present invention will be described with reference to FIG. Hereinafter, in a plurality of embodiments, the same numerals are given to the composition substantially the same as a 1st embodiment mentioned above, and explanation is omitted.
In the second embodiment, the fourth cam piece corresponding to the No. 2 cylinder and the eighth cam piece corresponding to the No. 4 cylinder are compared with the second cam piece corresponding to the No. 1 cylinder and the sixth cam piece corresponding to the No. 3 cylinder. Thus, the first inclined surface and the second inclined surface are long in the circumferential direction of the cam piece. For this reason, the surface pressure when the first arm portion and the first inclined surface are in sliding contact and the surface pressure when the second arm portion and the second inclined surface are in sliding contact is reduced, and the durability of the cam piece is increased. Can do.

(Third embodiment)
A third embodiment of the present invention will be described with reference to FIG.
In the third embodiment, the first guide 31 and the second guide 36 are provided on one side of the first cam portion 22 and the second cam portion 25 in the axial direction. The first guide 31 and the second guide 36, and the first cam portion 22 and the second cam portion 25 are connected by a connecting portion 29.
The first arm portion 41 of the shifter 45 can be slidably contacted with an end surface in the axial direction where the first thick portion 33 of the first guide 31 is provided. The second arm portion 42 can be slidably contacted with an axial end surface provided with the second thick portion 38 and the like of the second guide 36.
In the third embodiment, the distance between one cam piece 20 and the other cam piece 21 can be reduced. Therefore, it is suitable when the interval between the two intake valves provided in one cylinder is narrow, that is, when the distance between the rocker arms 11 and 12 is short.

(Fourth embodiment)
A fourth embodiment of the present invention will be described with reference to FIG.
In the fourth embodiment, the end surface of the first guide 31 provided with the first inclined surface 32 and the like and the end surface of the second guide 36 provided with the second inclined surface 37 and the like are provided so as to face each other. The arm portion 41 of the shifter 45 is provided between the first thick portion 33 of the first guide 31 and the second thick portion 38 of the second guide 36.
In 4th Embodiment, the number of the arm parts 41 of the shifter 45 can be reduced with respect to 1st-3rd embodiment mentioned above.

(Other embodiments)
In the above-described embodiment, for example, a cam shift device that opens and closes an intake valve of a four-cylinder engine and changes the opening and closing timing of the intake valve has been described. On the other hand, in other embodiments, the cam shift device can be applied to a single-cylinder engine or a multi-cylinder engine. The cam shift device can also be applied to open / close driving of the exhaust valve.

  In the above-described embodiment, the cam shift device including the cam piece including the first cam portion having the first base and the first nose and the second cam portion having the second base and the second nose has been described. On the other hand, in another embodiment, the cam shift device includes a cam piece including a first cam portion having a first base and a first nose, and a second cam portion having only a second base. May be.

  As described above, the present invention is not limited to the above-described embodiment. In addition to combining the above-described plurality of embodiments, the present invention can be implemented in various forms without departing from the spirit of the invention.

10 ... Cam shift device 11 ... Rocker arm (sliding contact member)
DESCRIPTION OF SYMBOLS 13 ... Cam shaft 22 ... 1st cam part 25 ... 2nd cam part 31 ... 1st guide 36 ... 2nd guide 41 ... 1st arm part (arm part)
42 ... 2nd arm part (arm part)
43 ... Actuator

Claims (5)

A rotatable camshaft (13);
A first base having a cylindrical first base (23) and a first nose (24) projecting from the first base in one of the radial directions is provided so as not to rotate relative to the camshaft and to reciprocate in the axial direction. 1 cam part (22),
A second cam portion (25) having a cylindrical second base (26) having the same diameter as the first base, which is provided adjacent to the first cam portion so as to be capable of reciprocating in the axial direction together with the first cam portion. When,
A sliding contact member (11) in sliding contact with an outer wall in the radially outward direction of the first cam portion and an outer wall in the radially outward direction of the second cam portion;
A first guide (31) having a first inclined surface (32) which is provided so as to be capable of reciprocating in the axial direction together with the first cam portion and the second cam portion, and which is inclined from one side of the axial direction toward the other direction. )When,
A second guide (36) having a second inclined surface (37) which is provided so as to be capable of reciprocating in the axial direction together with the first cam portion and the second cam portion, and which inclines in the positive rotation direction from the other axial direction to the other. )When,
A shifter shaft (40) extending substantially parallel to the camshaft and capable of reciprocating in the axial direction;
Arm portions (41, 42) fixed to the shifter shaft and slidably contacted with the first inclined surface of the first guide and the second inclined surface of the second guide;
An actuator (43) capable of reciprocating the shifter shaft in the axial direction within a movement range of the first cam portion and the second cam portion;
The first inclined surface and the second inclined surface are provided in a range that does not overlap the arm portion when viewed from the axial direction when the first nose and the sliding contact member are in sliding contact.
The first guide is provided in one axial direction of the first cam portion,
It said second guide is Kamushifuto device according to claim Rukoto provided in the axial direction of the other of the second cam portion (10). A rotatable camshaft (13);
A first base having a cylindrical first base (23) and a first nose (24) projecting from the first base in one of the radial directions is provided so as not to rotate relative to the camshaft and to reciprocate in the axial direction. 1 cam part (22),
A second cam portion (25) having a cylindrical second base (26) having the same diameter as the first base, which is provided adjacent to the first cam portion so as to be capable of reciprocating in the axial direction together with the first cam portion. When,
A sliding contact member (11) in sliding contact with an outer wall in the radially outward direction of the first cam portion and an outer wall in the radially outward direction of the second cam portion;
A first guide (31) having a first inclined surface (32) which is provided so as to be capable of reciprocating in the axial direction together with the first cam portion and the second cam portion, and which is inclined from one side of the axial direction toward the other direction. )When,
A second guide (36) having a second inclined surface (37) which is provided so as to be capable of reciprocating in the axial direction together with the first cam portion and the second cam portion, and which inclines in the positive rotation direction from the other axial direction to the other. )When,
A shifter shaft (40) extending substantially parallel to the camshaft and capable of reciprocating in the axial direction;
Arm portions (41, 42) fixed to the shifter shaft and slidably contacted with the first inclined surface of the first guide and the second inclined surface of the second guide;
An actuator (43) capable of reciprocating the shifter shaft in the axial direction within a movement range of the first cam portion and the second cam portion;
The first inclined surface and the second inclined surface are provided in a range that does not overlap the arm portion when viewed from the axial direction when the first nose and the sliding contact member are in sliding contact.
The arm portion is provided with a first arm portion (41) slidably contactable with an axial end surface of the first guide on which the first inclined surface is provided, and the second inclined surface of the second guide. And a second arm portion (42) slidably contactable with the axial end face . The first guide includes a first thick portion (33) provided perpendicularly to a rotation axis from an end of the first inclined surface at the rear in the rotation direction, and an end of the first inclined surface at the front in the rotation direction. A first thin portion (34) provided perpendicular to the rotation axis,
The second guide includes a second thick portion (38) provided perpendicularly to the rotation axis from an end of the second inclined surface in the rotational direction and a front end of the second inclined surface in the rotational direction. A second thin portion (39) provided perpendicular to the rotation axis,
The first thick part and the second thick part are provided in a range that does not overlap the arm part when viewed from the axial direction when the first nose and the sliding contact member are in sliding contact with each other.
The first thin portion and the second thin portion are provided in a range that overlaps with the arm portion when viewed in the axial direction when the first nose and the sliding contact member are in sliding contact with each other. Or the cam shift apparatus of 2 . The second cam portion has a second nose (27) protruding in one of the radial directions from the second base at a phase different from the first nose in the rotational direction,
The first inclined surface and the second inclined surface are viewed from the axial direction when the first nose and the sliding contact member are in sliding contact and when the second nose and the sliding contact member are in sliding contact. The cam shift device according to any one of claims 1 to 3, wherein the cam shift device is provided in a range that does not overlap the arm portion. The first cam portion, the second cam portion, the first guide, and the second guide constitute a cam piece (20) that moves the sliding contact member,
The cam shift device according to any one of claims 1 to 4 , wherein a plurality of the cam pieces are provided on the cam shaft so as to be capable of reciprocating in the axial direction.

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