JP5692604B2 - Valve lift adjustment device - Google Patents

Description

  The present invention relates to a valve lift adjusting device.

  2. Description of the Related Art A valve lift adjustment device is known that includes two types of plate cams that can convert rotational movement of a cam shaft of an internal combustion engine into reciprocating linear motion of an engine valve, and adjusts the valve lift of the engine valve by switching each plate cam. Yes. In the valve lift adjusting device disclosed in Patent Document 1, the two types of plate cams are fitted so as to be able to transmit rotation to the cam shaft and be relatively movable in the axial direction. The plate cams are adjacent to each other in the axial direction and are integrally formed with each other. Each plate cam is switched by a slider.

  The slider is a cylindrical member that moves in the axial direction integrally with the plate cam. The slider has a meandering groove on its outer wall, and its axial position is regulated by a regulating pin inserted into this groove. In Patent Document 1, the front half of the groove is for moving the slider so as to switch to one plate cam. Further, the latter half of the groove is for moving the slider so as to switch to the other plate cam. The valve lift adjusting device moves the slider to two axial positions with one regulating pin.

US Patent Application Publication No. 2011/0247577

  In the valve lift adjusting device disclosed in Patent Document 1, it is necessary to insert the regulating pin into the groove while the slider rotates about ¼ turn. Therefore, the drive part of a control pin needs to operate a control pin quickly. The operating speed of the drive unit needs to be higher as the rotational speed of the internal combustion engine is higher. When the insertion of the restriction pin into the groove is delayed, there is a problem that the engagement between the restriction pin and the groove becomes shallow or disengaged.

  In order to solve the above problem, it is conceivable that the operation start timing of the regulation pin is advanced. However, if the operation start timing of the restriction pin is advanced, for example, when the restriction pin is inserted into the first half of the groove, the restriction pin may be engaged with the second half of the groove, resulting in an excessive load on the restriction pin. There is.

  The present invention has been made in view of the above-described points, and an object of the present invention is to be able to move the slider to two axial positions with one restricting member and to reliably insert the restricting pin into the groove. It is providing the valve lift adjustment apparatus which can be performed.

  The present invention is a valve lift adjusting device that adjusts a valve lift of an engine valve of an internal combustion engine, and includes a first plate cam and a second plate cam that are fitted to a cam shaft, and a cylindrical shape having an engagement groove on a radially outer wall. A slider coupled to the camshaft so as to be able to transmit rotation and relatively move in the axial direction, a restricting member that can be inserted into and removed from the engaging groove of the slider, and a drive unit that inserts and operates the restricting member into the engaging groove. Prepare.

  The slider includes a first plate cam and a second plate in an axial direction between a first operating position where the engine valve is interlocked with the first plate cam and a second operating position where the engine valve is interlocked with the second plate cam. It can move together with the cam. The axial width of the engaging groove of the slider is equal to or greater than the value obtained by adding the axial length of the tip of the restricting member and the sliding amount of the slider.

Further, one of the inner walls of the engaging groove protrudes toward the other wall toward the rear in the rotational direction of the slider, and when the slider is rotated, the slider is moved to the second operating position when engaged with the restriction member. A first protrusion to be moved is formed. Further, the other wall protrudes toward the one wall toward the rear side in the rotational direction at a position different from the first protrusion in the circumferential direction, and engages with the regulating member when the slider rotates, so that the slider is first A second protrusion is formed to be moved to the operating position.
The engagement groove constitutes another valve lift adjustment device and can be engaged with another restriction member different from the restriction member, and is shared with the other valve lift adjustment device. . The other valve lift adjusting device moves the slider between the first operating position and a third operating position for interlocking the engine valve with a third plate cam different from the first plate cam and the second plate cam. Is possible.

Therefore, according to the present invention, the slider can be moved to two axial positions by one regulating member.
According to the present invention, when the slider is moved from the first operation position to the second operation position, the circumferential relative position of the restricting member with respect to the slider coincides with the first protrusion and then reaches the first protrusion. In the meantime, the restricting member may be inserted into the engaging groove. The same applies when the slider is moved from the second operating position to the first operating position.

  Therefore, for example, when the ratio of protrusions in the circumferential direction is ¼ or less, the drive unit may insert the regulating member into the groove while the slider rotates about ¾ turn. Therefore, the restricting member can be reliably inserted into the engaging groove even when the operating speed of the drive unit is relatively slow.

It is a figure which shows the valve system using the valve lift adjustment apparatus by 1st Embodiment of this invention. It is the II-II sectional view taken on the line of FIG. It is the III-III sectional view taken on the line of FIG. It is the IV-IV sectional view taken on the line of FIG. It is a figure which shows the valve system seen from the arrow V direction of FIG. It is a perspective view which shows the 1st protrusion side among the sliders of FIG. It is a perspective view which shows the 2nd protrusion side among the sliders of FIG. It is a figure which shows the state in which the control pin which protruded in the slider side from the state of FIG. 2 was inserted in the engaging groove. It is a figure which shows the state which the slider moved to the high rotation position from the state of FIG. FIG. 10 is a diagram illustrating a state in which a restriction pin protruding from the state of FIG. 9 to the slider side is inserted into the engagement groove. It is a figure which shows the state by which the 2nd control pin protruded to the slider side from the state of FIG. 2 was inserted in the engagement groove | channel. It is a figure which shows the state which the slider moved to the low load position from the state of FIG. It is a figure which shows the state by which the 2nd control pin protruded to the slider side from the state of FIG. 12 was inserted in the engagement groove | channel. It is a figure explaining the action | operation when moving the slider of FIG. 2 from a low rotation position to a high rotation position. It is a figure explaining the action | operation when moving the slider of FIG. 2 from a high rotation position to a low rotation position. It is a figure explaining the action | operation when moving the slider of FIG. 2 from a low rotation position to a low load position. It is a figure explaining the action | operation when moving the slider of FIG. 2 from a low load position to a low rotation position.

Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
The valve lift adjusting device according to the first embodiment of the present invention is a variable valve mechanism of a cam switching type and is used in the valve system shown in FIG. The valve system 20 is a system that opens and closes an intake valve 44 of an internal combustion engine.

  As shown in FIGS. 1 to 5, the valve system 20 includes a camshaft 21, a low-rotation cam 25, a high-rotation cam 30, a low-load cam 35, a roller rocker 40, a lash adjuster 43, an intake valve 44, a slider. 50 and an actuator 70.

  The low rotation cam 25, the high rotation cam 30, the slider 50, and the actuator 70 constitute the first valve lift adjusting device 10. In the first valve lift adjusting device 10, the low-rotation cam 25 corresponds to the “first plate cam” recited in the claims, and the high-rotation cam 30 corresponds to the “second plate” recited in the claims. Corresponds to “plate cam”.

The low load cam 35, the low rotation cam 25, the slider 50 and the actuator 70 constitute the second valve lift adjusting device 11. In the second valve lift adjusting device 11, the low load cam 35 corresponds to the “first plate cam” described in the claims, and the low rotation cam 25 is the “second cam” described in the claims. Corresponds to “plate cam”.
The low-rotation cam 25 functions as a “first plate cam” in the first valve lift adjustment device 10, and also functions as a “second plate cam” in the second valve lift adjustment device 11.

  The cam shaft 21 is rotatably supported by a cylinder head 12 at a location not shown. As shown in FIG. 2 to FIG. 4, spline external teeth extending in the axial direction are formed on the radially outer wall of the cam shaft 21. An output shaft of an internal combustion engine (not shown) is connected to the camshaft 21 via a timing chain or the like. The cam shaft 21 rotates integrally with the output shaft.

The low-rotation cam 25, the high-rotation cam 30, the low-load cam 35, and the slider 50 are made of the same member and are integrally formed with each other.
The low-rotation cam 25 is a disc cam that is fitted to the cam shaft 21. A cam lobe 27 protruding from the base circle 26 in the radially outward direction is formed on the radially outer wall of the low rotation cam 25.

  Spline inner teeth extending in the axial direction are formed on the inner diameter wall of the low-rotation cam 25. The spline inner teeth mesh with the spline outer teeth of the camshaft 21. The low-rotation cam 25 can transmit rotation to the cam shaft 21 and can move relative to the axial direction.

  The low-rotation cam 25 and the roller rocker 40 constitute a low-rotation cam mechanism that converts the rotational motion of the cam shaft 21 into the reciprocating linear motion of the intake valve 44. In the low rotation cam mechanism, the low rotation cam 25 functions as an original node, and the roller rocker 40 functions as a follower.

  The high rotation cam 30 is a disc cam fitted to the cam shaft 21 and is adjacent to the low rotation cam 25 in the axial direction. A cam lobe 32 protruding from the base circle 31 by a predetermined amount in the radially outward direction is formed on the radially outer wall of the high rotation cam 30. The base circle 26 and the base circle 31 are formed in the same plane with no step.

  The cam profile of the high rotation cam 30 is different from the cam profile of the low rotation cam 25. For example, the maximum cam lift of the high rotation cam 30 is larger than the maximum cam lift of the low rotation cam 25. Further, the cam operating angle of the high rotation cam 30 is larger than the cam operating angle of the low rotation cam 25.

  Spline inner teeth extending in the axial direction are formed on the inner wall of the high-rotation cam 30. The spline inner teeth mesh with the spline outer teeth of the camshaft 21. The high-rotation cam 30 can transmit rotation to the cam shaft 21 and can move relative to the axial direction.

  The high-rotation cam 30 and the roller rocker 40 constitute a high-rotation cam mechanism that converts the rotational motion of the cam shaft 21 into the reciprocating linear motion of the intake valve 44. In the high rotation cam mechanism, the high rotation cam 30 functions as an original node, and the roller rocker 40 functions as a follower.

The low load cam 35 is a disc cam fitted to the cam shaft 21 and is adjacent to the low rotation cam 25 in the axial direction on the opposite side of the high rotation cam. The outer wall of the low-load cam 35 forms a base circle 36, but does not form a cam lobe. That is, the cam 35 for low load has a perfect cam profile and zero cam lift.
The base circle 36 is formed in the same plane with no step with respect to the base circle 26 and the base circle 31.

Spline inner teeth extending in the axial direction are formed on the inner diameter wall of the low load cam 35. The spline inner teeth mesh with the spline outer teeth of the camshaft 21. The low load cam 35 can transmit rotation to the cam shaft 21 and can move relative to the axial direction.
The low-load cam 35 and the roller rocker 40 constitute a low-load cam mechanism that does not open or close the intake valve 44 even when the cam shaft 21 rotates, that is, stops the cylinder.

The roller rocker 40 includes a swing arm 41 and a roller 42.
The swing arm 41 has one end in contact with the lash adjuster 43 and the other end in contact with the tip of the stem 45 of the intake valve 44. The swing arm 41 can swing so that the other end approaches and separates from the camshaft 21 with one end serving as a fulcrum.

  The roller 42 is provided between one end and the other end of the swing arm 41. As shown in FIG. 1, the roller 42 contacts the radially outer wall of the low-rotation cam 25 when each cam and the slider 50 are positioned at the center in the axial direction. The axial position of each cam and slider 50 at this time is referred to as a “low rotation position”.

Further, as shown in FIG. 9 to be described later, the roller 42 abuts against the radially outer wall of the high-rotation cam 30 when each cam and the slider 50 are positioned on one side in the axial direction. The axial position of each cam and slider 50 at this time is defined as a “high rotation position”.
Further, as shown in FIG. 12 to be described later, the roller 42 comes into contact with the radially outer wall of the low load cam 35 when each cam and the slider 50 are positioned on the other side in the axial direction. The axial position of each cam and slider 50 at this time is referred to as a “low load position”.

  1 to 5, the intake valve 44 is a poppet valve and can open and close the intake port of the cylinder of the internal combustion engine. The intake valve 44 is urged in a valve closing direction by a spring (not shown), and when the intake valve 44 is pushed by the cam lobe 27 of the low-rotation cam 25 or the cam lobe 32 of the high-rotation cam 30 through the swing arm 41, Is released.

The slider 50 is formed in a cylindrical shape and is adjacent to the low-load cam 35 in the axial direction on the opposite side of the low-rotation cam 25. Spline inner teeth extending in the axial direction are formed on the radially inner wall of the slider 50. The spline inner teeth mesh with the spline outer teeth of the camshaft 21. The slider 50 is connected to the camshaft 21 so as to be capable of transmitting rotation and relatively moving in the axial direction.
The outer diameter wall of the slider 50 has an engagement groove 51 extending in the circumferential direction. The engagement groove 51 will be described in detail later.

  The slider 50 can move integrally with each cam in the axial direction between a low rotation position and a high rotation position, and between a low rotation position and a low load position. The low rotation position is a position where the intake valve 44 is interlocked with the low rotation cam 25. The high rotation position is a position where the intake valve 44 is interlocked with the high rotation cam 30. The low load position is a position where the low load cam 35 and the roller 42 are brought into contact with each other. When the slider 50 moves in the axial direction, each cam moves together with the slider 50.

  In the first valve lift adjusting device 10, the low rotation position corresponds to a “first operation position”, and the high rotation position corresponds to a “second operation position”. On the other hand, in the second valve lift adjusting device 11, the low rotation position corresponds to the “second operation position”, and the low load position corresponds to the “first operation position”.

The actuator 70 is a linear operation type electromagnetic actuator, is fixed to the cylinder head 12, and includes restriction pins 71 and 72 and a drive unit 73.
The regulation pins 71 and 72 correspond to “regulation members” described in the claims. The restricting pins 71 and 72 are arranged so that the axial direction of the restricting pins 71 and 72 coincides with the radial direction of the slider 50, and are movable in a direction approaching and separating from the slider 50.

  The regulation pins 71 and 72 are inserted into the engagement groove 51 when approaching the slider 50, and come out of the engagement groove 51 when separated from the slider 50. That is, the regulation pins 71 and 72 can be inserted into and removed from the engaging groove 51. When the restriction pins 71 and 72 are inserted into the engagement groove 51, the restriction pins 71 and 72 engage with the inner wall of the engagement groove 51 to restrict the position of the slider 50 in the axial direction.

  The drive unit 73 is fixed to an end portion of the regulation pin 71 in the sleeve 74, a sleeve 74 that supports the regulation pins 71 and 72 so as to be able to reciprocate, a fixed core 75 and 76 that are fixed to the inner wall of the sleeve 74. A movable core 77, a movable core 78 fixed to the end of the regulation pin 72 in the sleeve 74, a coil 79 comprising a winding wound around the fixed core 75 and generating a magnetic field when energized, and a fixed core 76 And a coil 80 that generates a magnetic field when energized.

  The movable core 77 includes a permanent magnet that repels the fixed core 75 magnetized by the magnetic field of the coil 79. The drive unit 73 inserts the regulation pin 71 into the engagement groove 51 by energizing the coil 79 and separating the movable core 77 from the fixed core 75. Further, the drive unit 73 allows the restriction pin 71 to come out of the engagement groove 51 by stopping energization of the coil 79 and releasing the magnetization of the fixed core 75.

  The movable core 78 includes a permanent magnet that repels the fixed core 76 magnetized by the magnetic field of the coil 80. The drive unit 73 inserts the regulation pin 72 into the engagement groove 51 by energizing the coil 80 and separating the movable core 78 from the fixed core 76. Further, the drive unit 73 allows the regulation pin 72 to come out of the engagement groove 51 by stopping energization of the coil 80 and releasing the magnetization of the fixed core 76.

Next, the engagement groove 51 of the slider 50 will be described in detail with reference to FIGS. 1 and 3 to 7.
The axial width X of the engagement groove 51 is equal to a value obtained by adding the axial length Y of the tip end portion of the restriction pin 71, the slide amount Z of the slider 50, and a predetermined axial play. The slide amount Z is a moving distance when the slider 50 moves from the low rotation position to the high rotation position. The movement distance when the slider 50 moves from the low rotation position to the high rotation position is the same as the movement distance when the slider 50 moves from the low rotation position to the low load position.
In the present embodiment, the axial width X of the engagement groove 51 is the same over the entire circumference. Further, the engaging groove 51 extends in a direction orthogonal to the axial direction of the slider 50.

  Assuming that one of the inner walls of the engagement groove 51 in the axial direction is the first wall 52 and the other wall is the second wall 53, the first wall 52 is closer to the rear side in the rotational direction of the slider 50. A first protrusion 54 protruding toward 53 is formed. The front wall 55 in the rotational direction of the first protrusion 54 is configured such that when the cams and the slider 50 are positioned at the low rotation position and the slider 50 is rotating, the slider 50 is engaged with the restriction pin 71. Move to.

  In the present embodiment, the protruding length of the first protrusion 54 is the same as the slide amount Z. Further, the radially outer surface 56 of the first protrusion 54 is formed in the same plane with no step with respect to the radially outer surface 68 at the end of the slider 50.

  The second wall 53 forms a second protrusion 58 that protrudes toward the first wall 52 toward the rear side in the rotational direction at a position different from the first protrusion 54 in the circumferential direction. The front wall 59 in the rotational direction of the second protrusion 58 engages with the restriction pin 71 when the cams and the slider 50 are positioned at the high rotational position and the slider 50 is rotating. Move to.

  In the present embodiment, the protruding length of the second protrusion 58 is the same as the slide amount Z. In addition, the outer surface 60 in the radial direction of the second protrusion 58 is formed in the same plane with no step with respect to the outer surface 68.

The bottom wall of the engaging groove 51 includes a first base surface 62, a second base surface 63, a first up surface 64, a first down surface 65, a second up surface 66, and a second down surface 67. Have
The first base surface 62 is located between the second protrusion 58 and the first protrusion 54 in the rotational direction, and extends in the circumferential direction from the outer diameter surface 68 at a predetermined depth D. The second base surface 63 is located between the first protrusion 54 and the second protrusion 58 in the rotational direction, and extends in the circumferential direction from the outer diameter surface 68 at a predetermined depth D.

  When the circumferential position of the rear end 57 in the rotational direction of the first protrusion 54 is the first rear end position, the first rising surface 64 is located between the first base surface 62 and the first rear end position, The depth from the outer diameter surface 68 is shallower toward the rear side in the rotation direction. The first descending surface 65 is located between the first rear end position and the second base surface 63, and the depth from the outer diameter surface 68 is deeper toward the rear side in the rotation direction.

  If the circumferential position of the rear end 61 in the rotational direction of the second protrusion 58 is the second rear end position, the second descending surface 67 is located between the second base surface 63 and the second rear end position, The depth from the outer diameter surface 68 is shallower toward the rear side in the rotation direction. The second descending surface 67 is located between the second rear end position and the first base surface 62, and the depth from the outer diameter surface 68 is deeper toward the rear side in the rotational direction.

  The first base surface 62, the first ascending surface 64, the first descending surface 65, the second base surface 63, the second ascending surface 66, and the second descending surface 67 are continuous in the circumferential direction from the radially outer surface 68. It is formed to change. The first protrusion 54 and the first descending surface 65 are connected without a step in the circumferential direction. The second protrusion 58 and the second descending surface 67 are connected without a step in the circumferential direction.

Next, the function of the drive part 73 is explained in full detail based on FIG.1, FIG.9, FIG.11.
When the drive unit 73 moves the slider 50 from the low rotation position of FIG. 1 to the high rotation position of FIG. 9, when the circumferential relative position of the restriction pin 71 with respect to the slider 50 coincides with the first protrusion 54, the drive unit 73 moves the restriction pin 71. The operation for inserting into the engaging groove 51 is started. Further, when moving the slider 50 from the low rotation position to the high rotation position, the drive unit 73 stops energization when the circumferential relative position of the restriction pin 71 with respect to the slider 50 coincides with the first upward surface 64.

  When the drive unit 73 moves the slider 50 from the high rotation position in FIG. 9 to the low rotation position in FIG. 1, when the circumferential relative position of the restriction pin 71 with respect to the slider 50 coincides with the second protrusion 58, the drive unit 73 moves the restriction pin 71. The operation for inserting into the engaging groove 51 is started. Further, when moving the slider 50 from the high rotation position to the low rotation position, the drive unit 73 stops energization when the circumferential relative position of the restriction pin 71 with respect to the slider 50 coincides with the second upward surface 66.

  When the drive unit 73 moves the slider 50 from the low load position in FIG. 12 to the low rotation position in FIG. 1, when the circumferential relative position of the restriction pin 72 with respect to the slider 50 coincides with the first protrusion 54, the drive unit 73 moves the restriction pin 72. The operation for inserting into the engaging groove 51 is started. Further, when moving the slider 50 from the low load position to the low rotation position, the drive unit 73 stops energization when the circumferential relative position of the restriction pin 72 with respect to the slider 50 coincides with the first upward surface 64.

  When the drive unit 73 moves the slider 50 from the low rotation position in FIG. 1 to the low load position in FIG. 12, when the circumferential relative position of the restriction pin 72 with respect to the slider 50 matches the second protrusion 58, the drive unit 73 moves the restriction pin 72. The operation for inserting into the engaging groove 51 is started. Further, when moving the slider 50 from the low rotation position to the low load position, the drive unit 73 stops energization when the circumferential relative position of the restriction pin 72 with respect to the slider 50 coincides with the second upward surface 66.

Next, the operation of the valve system 20 will be described with reference to FIGS. 1 and 8 to 17.
As shown in FIG. 1, when the cam shaft 21 rotates when the slider 50 is positioned at the low rotation position, the rotational movement of the low rotation cam 25 is transmitted to the swing arm 41 via the roller 42, and the intake valve 44 reciprocates. Converted to linear motion.

  In the state of FIG. 1, for example, when the engine speed reaches a high rotation range, when the circumferential relative position of the restriction pin 71 with respect to the slider 50 coincides with the first protrusion 54, the drive unit 73 pushes the restriction pin 71 into the engagement groove 51. The operation to plug in is started. The start position of the operation coincides with the start point of the arrow “ON” in FIG. The restriction pin 71 is inserted into the engagement groove 51 after the circumferential relative position with respect to the slider 50 coincides with the first protrusion 54 and before reaching the second downward surface 67.

  As shown in FIG. 8, when the slider 50 rotates together with the cam shaft 21 with the restriction pin 71 inserted in the engagement groove 51, the front wall 55 of the first protrusion 54 of the slider 50 engages with the restriction pin 71. The position of the slider 50 in the axial direction is restricted, and the slider 50 slides to the high rotation position side as indicated by an arrow A1 in FIG. When the slider 50 slides to the high rotation position side, the drive unit 73 stops energization. At this time, the restricting pin 71 is pushed outward in the radial direction by the first rising surface 64 of the engaging groove 51, and comes out of the engaging groove 51 and returns in the radially outward direction as indicated by an arrow “return” in FIG. 14. The position where the energization is stopped coincides with the end point of the arrow “ON” in FIG. 14, and also coincides with the start point of the arrow “switch”.

  As shown in FIG. 9, when the cam shaft 21 rotates when the slider 50 is positioned at the high rotation position, the rotational movement of the high rotation cam 30 is transmitted to the swing arm 41 via the roller 42, and the intake valve 44 reciprocates. Converted to linear motion. When the rotational motion of the high-rotation cam 30 is converted into the reciprocating linear motion of the intake valve 44, the valve lift is larger than when the rotational motion of the low-rotation cam 25 is converted into the reciprocating linear motion of the intake valve 44. Become.

  In the state of FIG. 9, for example, when the engine speed reaches a low rotation range, when the circumferential relative position of the restriction pin 71 with respect to the slider 50 coincides with the second protrusion 58, the drive unit 73 pushes the restriction pin 71 into the engagement groove 51. The operation to plug in is started. The start position of the operation coincides with the start point of the arrow “ON” in FIG. The restriction pin 71 is inserted into the engagement groove 51 between the time when the circumferential relative position with respect to the slider 50 matches the second protrusion 58 and the time when the restriction pin 71 reaches the first downward surface 65.

  As shown in FIG. 10, when the slider 50 rotates together with the cam shaft 21 with the restriction pin 71 inserted into the engagement groove 51, the front wall 59 of the second protrusion 58 of the slider 50 engages with the restriction pin 71. The position of the slider 50 in the axial direction is restricted, and the slider 50 slides to the low rotation position side as indicated by an arrow A2 in FIG. When the slider 50 slides to the low rotation position side, the drive unit 73 stops energization. At this time, the restricting pin 71 is pushed outward in the radial direction by the second upward surface 66 of the engaging groove 51, and comes out of the engaging groove 51 and returns in the radially outward direction as indicated by an arrow “return” in FIG. 15. The position where the energization is stopped coincides with the end point of the arrow “ON” in FIG. 15 and also coincides with the start point of the arrow “switch”.

  When the operating state of the internal combustion engine reaches a low load region in the state of FIG. 1, when the circumferential relative position of the restriction pin 72 with respect to the slider 50 coincides with the second protrusion 58, the drive unit 73 engages the restriction pin 72 with the engagement groove. The operation for inserting into 51 is started. The start position of the operation coincides with the start point of the arrow “ON” in FIG. The restriction pin 72 is inserted into the engagement groove 51 between the time when the circumferential relative position with respect to the slider 50 matches the second protrusion 58 and the time when the restriction pin 72 reaches the first downward surface 65.

  As shown in FIG. 11, when the slider 50 rotates together with the cam shaft 21 with the restriction pin 72 inserted into the engagement groove 51, the front wall 59 of the second protrusion 58 of the slider 50 engages with the restriction pin 72. The position of the slider 50 in the axial direction is restricted, and the slider 50 slides to the low load position side as indicated by an arrow A3 in FIG. When the slider 50 slides to the low load position side, the drive unit 73 stops energization. At this time, the restricting pin 72 is pushed outward in the radial direction by the second rising surface 66 of the engaging groove 51, and comes out of the engaging groove 51 and returns in the radially outward direction as indicated by an arrow “return” in FIG. 16. The position where the energization is stopped coincides with the end point of the arrow “ON” in FIG. 16 and also coincides with the start point of the arrow “switch”.

  As shown in FIG. 12, when the cam shaft 21 rotates when the slider 50 is positioned at the low load position, the swing arm 41 does not swing and the intake valve 44 does not open or close. As a result, the corresponding cylinder is deactivated and the fuel efficiency is improved. For example, the energy regeneration efficiency is increased in a hybrid car.

  In the state of FIG. 12, when the operation state of the internal combustion engine is removed from the low load range, when the circumferential relative position of the restriction pin 72 with respect to the slider 50 coincides with the first protrusion 54, the drive unit 73 causes the restriction pin 72 to engage with the engagement groove. The operation for inserting into 51 is started. The start position of the operation coincides with the start point of the arrow “ON” in FIG. The restriction pin 72 is inserted into the engagement groove 51 between the time when the circumferential relative position with respect to the slider 50 coincides with the first protrusion 54 and the time when the restriction pin 72 reaches the second downward surface 67.

  As shown in FIG. 13, when the slider 50 rotates together with the cam shaft 21 with the restriction pin 72 inserted into the engagement groove 51, the front wall 55 of the first protrusion 54 of the slider 50 engages with the restriction pin 72. The position of the slider 50 in the axial direction is restricted, and the slider 50 slides to the low rotation position side as indicated by an arrow A4 in FIG. When the slider 50 slides to the low rotation position side, the drive unit 73 stops energization. At this time, the restricting pin 72 is pushed in the radially outward direction by the first rising surface 64 of the engaging groove 51, and comes out of the engaging groove 51 and returns in the radially outward direction as indicated by an arrow “return” in FIG. The position where the energization is stopped coincides with the end point of the arrow “ON” in FIG. 17, and also coincides with the start point of the arrow “switch”.

As described above, in this embodiment, the axial width X of the engagement groove 51 of the slider 50 is a value obtained by adding the axial length Y of the tip end portion of the restriction pin 71 and the slide amount Z of the slider 50. Bigger than.
Further, the first wall 52 of the engaging groove 51 protrudes toward the second wall 53 toward the rear side in the rotational direction, and when the slider 50 is rotated, when the slider 50 is engaged with the restriction pin 71, the slider 50 is rotated from the low rotation position to the high rotation speed. A first protrusion 54 to be moved to a position is formed.

The second wall 53 protrudes toward the first wall 52 toward the rear side in the rotational direction at a position different from the first protrusion 54 in the circumferential direction, and when the slider 50 is rotated, the second wall 53 is engaged with the restriction pin 71. A second protrusion 58 for moving 50 from the high rotation position to the low rotation position is formed.
Therefore, according to the valve lift adjusting devices 10 and 11 according to the present embodiment, the slider 50 can be moved to the low rotation position and the high rotation position by one restriction pin 71.

In the present embodiment, the second protrusion 58 moves the slider 50 from the low rotation position to the low load position when engaged with the restriction pin 72 when the slider 50 rotates. The first protrusion 54 moves the slider 50 from the low load position to the low rotation position when engaged with the restriction pin 72 during the rotation of the slider 50.
Therefore, according to the present embodiment, the slider 50 can be moved to the low rotation position and the low load position with one restriction pin 72.

  Further, when the slider 50 is moved from the low rotation position to the high rotation position, the period from the time when the circumferential relative position of the restriction pin 71 to the slider 50 coincides with the first protrusion 54 until the next arrival at the first protrusion 54. In addition, the restriction pin 71 may be inserted into the engagement groove 51. The same applies when the slider 50 is moved from the high rotation position to the low rotation position, when the slider 50 is moved from the low rotation position to the low load position, and when the slider 50 is moved from the low load position to the low rotation position.

Therefore, for example, when the ratio of the protrusions 54 and 58 in the circumferential direction is ¼ or less, the drive unit 73 causes the restriction pin 71 to be engaged with the engaging groove 51 while the slider 50 rotates about ¾ turn. Just plug it in. Therefore, the restriction pin 71 can be reliably inserted into the engagement groove 51 even if the operating speed of the drive unit 73 is relatively slow.
Therefore, according to this embodiment, the physique of the drive part 73 can be made small and it is easy to ensure a mounting space.

In the present embodiment, the bottom wall of the engagement groove 51 has the first downward surface 65 on the rear side in the rotational direction with respect to the first protrusion 54 and the first upward surface 64, and the second protrusion 58 and the second upward surface. A second downward surface 67 is provided on the rear side in the rotational direction with respect to the surface 66.
Therefore, when the slider 50 rotates with the regulation pin 71 inserted into the engagement groove 51, the regulation pin 71 is inserted back by the up surfaces 64 and 66 and then slides on the down surfaces 65 and 67. It protrudes gently toward the base surfaces 62 and 63. For this reason, the regulation pin 71 can avoid bouncing when contacting the base surfaces 62 and 63. Therefore, it is possible to prevent the engagement between the regulation pin 71 and the engagement groove 51 due to the bounce.

In the present embodiment, the first base surface 62, the first rising surface 64, the first downward surface 65, the second base surface 63, the second upward surface 66, and the second downward surface 67 are deep from the outer surface 68. Is formed so as to continuously change in the circumferential direction.
Therefore, when the slider 50 rotates with the restriction pin 71 inserted into the engagement groove 51, the movement of the restriction pin 71 in the radial direction can be made smooth. Therefore, it is possible to avoid the bounce of the regulation pin 71.

In the present embodiment, the first protrusion 54 and the first descending surface 65 are connected without a step in the circumferential direction. Further, the second protrusion 58 and the second descending surface 67 are connected without a step in the circumferential direction.
Therefore, when the restriction pin 71 protruding so as to come into contact with the protrusions 54 and 58 moves relative to the descending surfaces 65 and 67, the bounce of the restriction pin 71 can be avoided.

Further, in the present embodiment, the drive unit 73 moves the slider 50 in the circumferential direction relative to the slider 50 when moving the slider 50 from the low rotation position to the high rotation position and when moving the slider 50 from the low load position to the low rotation position. The restriction pin 71 is inserted into the engagement groove 51 between the time when the position coincides with the first protrusion 54 and the time when the position reaches the second descending surface 67.
Therefore, it is possible to reliably avoid the restriction pin 71 bouncing at the first base surface 62.

Further, in the present embodiment, the drive unit 73 moves the slider 50 in the circumferential direction relative to the slider 50 when moving the slider 50 from the high rotation position to the low rotation position and when moving the slider 50 from the low rotation position to the low load position. The restriction pin 71 is inserted into the engagement groove 51 between the time when the position coincides with the second protrusion 58 and the time when the position reaches the first downward surface 65.
Therefore, it is possible to reliably avoid the restriction pin 71 bouncing at the second base surface 63.

  In the present embodiment, the drive unit 73 is an electromagnetic type that moves the regulation pin 71 toward the slider 50 when energized and allows the regulation pin 71 to move in the radially outward direction when energization is stopped. In addition, when the drive unit 73 moves the slider 50 from the low rotation position to the high rotation position, and when moving the slider 50 from the low load position to the low rotation position, the circumferential relative position of the restriction pin 71 with respect to the slider 50 is the first ascending position. When it coincides with the surface 64, the energization is stopped.

Further, when the slider 50 is moved from the high rotation position to the low rotation position, and when it is moved from the low rotation position to the low load position, the circumferential relative position of the restriction pin 71 with respect to the slider 50 coincides with the second upward surface 66. When energizing is stopped.
Therefore, the restriction pin 71 can be reliably returned to the radially outward direction by the operation of pushing the restriction pin 71 in the radially outward direction with the first upward surface 64 or the second upward surface 66.

(Other embodiments)
In other embodiments of the present invention, the axial width of the engagement groove may be different in the circumferential direction.
In another embodiment of the present invention, the engagement groove may be formed at a predetermined angle with respect to the axial direction.

In another embodiment of the present invention, the protruding lengths of the first protrusion and the second protrusion may be different from the sliding amount of the slider.
In another embodiment of the present invention, the radial outer surface of the first protrusion and the radial outer surface of the second protrusion may be formed to have a step with respect to the radial outer surface of the end portion of the slider.
In another embodiment of the present invention, the first protrusion and the second protrusion may be formed of a separate member from the slider.

Other embodiments of the invention may be used in a valve system for an exhaust valve.
Other embodiments of the present invention are not limited to valve systems that include roller rockers with swing arms, and may be used with other types of valve systems.

In another embodiment of the present invention, one valve lift adjusting device may be provided for the engine valve, or three or more may be provided.
In another embodiment of the present invention, instead of the low load cam, a cam having a different shape from the low rotation cam and the high rotation cam may be provided.
In another embodiment of the present invention, each cam and slider may be configured as separate members.

In another embodiment of the present invention, each cam and slider may be coupled to the camshaft by a fitting method other than spline fitting.
In another embodiment of the present invention, the spline internal teeth that engage with the camshaft need only be formed on at least a part of each cam and slider.

  In other embodiments of the present invention, the cam profile of the high rotation cam may make any difference to the cam profile of the low rotation cam. For example, the maximum cam lift may be the same and the cam operating angle may be different. Further, the cam operating angle is the same, and the maximum cam lift may be varied. Further, the maximum cam lift and the cam operating angle are the same, and the valve opening / closing timing may be varied.

  In another embodiment of the present invention, the drive unit moves the slider from the low rotation position to the high rotation position, and moves the slider from the low load position to the low rotation position. The operation for inserting the restriction pin into the engagement groove may be started after the relative position coincides with the first protrusion and until the next arrival at the first protrusion.

  In another embodiment of the present invention, the drive unit moves the slider from the high rotation position to the low rotation position, and moves the slider from the low rotation position to the low load position. The operation for inserting the restriction pin into the engagement groove may be started after the relative position coincides with the second protrusion and until the second protrusion is reached next.

  In another embodiment of the present invention, the drive unit moves the slider from the low rotation position to the high rotation position, and moves the slider from the low load position to the low rotation position. The energization may be stopped between the time when the relative position coincides with the first rising surface and the time when the first rear end position is passed.

  In another embodiment of the present invention, the drive unit moves the slider from the high rotation position to the low rotation position, and moves the slider from the low rotation position to the low load position. The energization may be stopped between the time when the relative position coincides with the first rising surface and the time when the first rear end position is passed.

  The present invention is not limited to the embodiments described above, and can be implemented in various forms without departing from the spirit of the invention.

10: First valve lift adjustment device (valve lift adjustment device)
11 ... Second valve lift adjustment device (valve lift adjustment device)
21 ... Cam shaft 25 ... Low-rotation cam (first plate cam, second plate cam)
30 ... High rotation cam (second plate cam) 35 ... Low load cam (first plate cam)
44 ... Intake valve (engine valve) 50 ... Slider 51 ... Engaging groove 52 ... First wall (one wall)
53 ... 2nd wall (the other wall) 54 ... 1st protrusion 58 ... 2nd protrusion 71, 72 ... Restriction pin (regulation member)
73: Drive unit X: Axial width Y: Axial length Z: Slide amount

Claims (8)

A valve lift adjusting device (10) for adjusting a valve lift of an engine valve (44) of an internal combustion engine,
The camshaft (21) that rotates integrally with the output shaft of the internal combustion engine is fitted so as to be capable of transmitting rotation and relatively movable in the axial direction, and the rotational motion of the camshaft can be converted into the reciprocating linear motion of the engine valve. A first plate cam (25);
Fitted to the camshaft so that it can transmit rotation and move in the axial direction, and has a cam profile different from that of the first plate cam, and can convert the rotational movement of the camshaft to the reciprocating linear movement of the engine valve. Second plate cam (30),
It is formed in a cylindrical shape, is connected to the camshaft so as to be able to transmit rotation and relatively move in the axial direction, and has an engagement groove (51) extending in the circumferential direction on the radially outer wall. The first plate cam and the second plate cam can be moved integrally between a first operation position interlocked with the first plate cam and a second operation position of interlocking the engine valve with the second plate cam. A slider (50),
A restricting member (71) that can be inserted into and removed from the engaging groove, engages with the inner wall of the engaging groove when inserted into the engaging groove, and restricts the axial position of the slider;
A drive unit (73) for inserting and operating the regulating member into the engaging groove;
With
The axial width (X) of the engaging groove is not less than a value obtained by adding the axial length (Y) of the tip end portion of the restricting member and the sliding amount (Z) of the slider,
One axial wall (52) of the inner walls of the engaging groove protrudes toward the other wall (53) toward the rear side in the rotational direction of the slider, and engages with the regulating member when the slider rotates. When combined, a first protrusion (54) is formed to move the slider to the second operating position,
The other wall protrudes toward the one wall toward the rear side in the rotation direction at a position different from the first protrusion in the circumferential direction, and engages with the restriction member when the slider rotates. Forming a second protrusion (58) to be moved to the first operating position ;
The engagement groove is between the first operating position and a third operating position in which the engine valve is interlocked with a third plate cam (35) different from the first plate cam and the second plate cam. The other valve lift adjusting device (11) that enables movement of the slider and that can be engaged with another restricting member (72) that is different from the restricting member. A valve lift adjusting device shared with the adjusting device.
  The valve lift adjusting device according to claim 1, wherein the axial width of the engaging groove is the same over the entire circumference.   The valve lift adjusting device according to claim 1, wherein the engagement groove extends in a direction orthogonal to the axial direction. The circumferential position of the rear end (57) in the rotational direction of the first protrusion is defined as a first rear end position,
When the circumferential position of the rear end (61) in the rotational direction of the second protrusion is the second rear end position,
The bottom wall of the engagement groove is
A first base surface (62) located between the second protrusion and the first protrusion in the rotational direction and extending in a circumferential direction from the outer radial surface (68) of the slider at a predetermined depth (D);
A second base surface (63) located between the first protrusion and the second protrusion in the rotational direction and extending in the circumferential direction from the outer diameter surface at the predetermined depth;
A first ascending surface (64) located between the first base surface and the first rear end position, the depth from the outer surface being shallower toward the rear side in the rotational direction;
A first descending surface (65) located between the first rear end position and the second base surface, the depth from the outer surface being deeper toward the rear side in the rotational direction;
A second ascending surface (66) located between the second base surface and the second rear end position, the depth from the outer surface being shallower toward the rear side in the rotational direction;
A second descending surface (67) located between the second rear end position and the first base surface, the depth from the outer surface being deeper toward the rear side in the rotational direction;
The valve lift adjusting device according to any one of claims 1 to 3, wherein the valve lift adjusting device is provided.   The first base surface, the first ascending surface, the first descending surface, the second base surface, the second ascending surface, and the second descending surface are continuous in the circumferential direction from the outer diameter surface. The valve lift adjusting device according to claim 4, wherein the valve lift adjusting device is formed so as to change. The first protrusion and the first descending surface are connected without a step in the circumferential direction,
6. The valve lift adjusting device according to claim 4, wherein the second protrusion and the second descending surface are connected without a step in a circumferential direction. The drive unit is
When the slider is moved from the first operating position to the second operating position, the period from the time when the circumferential relative position of the regulating member to the slider coincides with the first protrusion until the second descending surface is reached. And insert the restriction member into the engagement groove,
When the slider is moved from the second operating position to the first operating position, a time period from when the circumferential relative position of the restricting member to the slider coincides with the second protrusion until the first descending surface is reached. The valve lift adjusting device according to any one of claims 4 to 6, wherein the restriction member is inserted into the engagement groove. The drive unit is
When energized, it generates a magnetic force that moves the restricting member to the slider side, and when energization is stopped, the restricting member is allowed to move to the opposite side of the slider.
When the slider is moved from the first operating position to the second operating position, the circumferential relative position of the restricting member with respect to the slider coincides with the first base surface until the first rear end position is reached. Stop energizing between
When the slider is moved from the second operating position to the first operating position, the circumferential relative position of the regulating member with respect to the slider coincides with the second base surface until the second rear end position is reached. The valve lift adjusting device according to any one of claims 4 to 7, wherein the energization is stopped between the two.

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