JP2010048097A - Variable valve train for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a variable valve train for an internal combustion engine including a structure improving efficiency in installing work. <P>SOLUTION: This variable valve train changes on-off characteristics of an intake valve by rotating an arm assembly 50 to a slider 40, accompanying movement of the slider 40 in relation to the arm assembly 50 in an axial direction. A projection 43 is provided at an inner circumference side of the slider 40, and a circumferential groove 23 corresponding to the projection 43 is provided at an outer circumference side of the control shaft 20. Since the projection 43 is fitted in the circumference groove 23 and movement of the projection 43 in a circumferential direction in relation to the circumferential groove 23 is allowed, rotation of the slider 40 in relation to the control shaft 20 is allowed. Since the circumferential groove 23 and the projection 43 contact and movement of the projection 43 in the axial direction in relation to the circumferential groove 23 is regulated, movement of the slider 40 in the axial direction in relation to the control shaft 20 is disabled. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention is provided between an engine valve and a camshaft to change the opening and closing characteristics of the engine valve. The movable shaft moves in the axial direction, and the movable shaft is inserted into its own shaft hole. The present invention relates to a variable valve mechanism for an internal combustion engine including an interlocking body and an opening / closing body provided outside the interlocking body.

  An intake valve and an exhaust valve, which are engine valves of an internal combustion engine, are opened and closed through the drive of a camshaft, and the communication state between the combustion chamber and the intake pipe or the exhaust pipe, that is, introduction of intake air into the combustion chamber and exhaust gas from the combustion chamber, respectively. The discharge is controlled. Conventionally, these were opened and closed directly by a camshaft cam or via a rocker arm, but in recent years, variable valve mechanisms that change the opening and closing characteristics of these engine valves in accordance with the operating state of the internal combustion engine have been adopted ( Patent Document 1).

An example of the structure of such a variable valve mechanism will be described with reference to FIGS. 17 and 18.
The variable valve mechanism corresponds to a rocker shaft 122 disposed in the cylinder head along the axis of the camshaft, a control shaft 121 disposed in the rocker shaft 122 so as to be movable in the axial direction, and each cylinder. And a gear assembly 130 assembled around the rocker shaft 122. An actuator is connected to one end of the control shaft 121, and the control shaft 121 linearly moves in the axial direction by this actuator.

  As shown in FIGS. 17 and 18, the gear assembly 130 is disposed on the outer periphery of the rocker shaft 122, moves in the axial direction in conjunction with the control shaft 121, and around the control shaft 121 together with the slider 140. It is comprised by the combination with the arm assembly 150 which rotates. The arm assembly 150 includes an input arm 151 that receives a force from the camshaft, and an output arm 156 that opens the engine valve based on the force received by the input arm 151. Further, the input arm 151, the output arm 156, and the slider 140 are engaged with each other by a helical gear.

  In this variable valve mechanism, the control shaft 121 and the slider 140 can be interlocked by attaching a connection pin 181 and a bush 182 as connection auxiliary elements to the control shaft 121 (see FIG. 18). . When assembling, first, the arm hole 151 A formed in the input arm 151, the slider hole 141 A formed in the slider 140, the rocker shaft hole 122 A formed in the rocker shaft 122, and the gap between the rocker shaft 122 and the slider 140. The pre-assembled state in which the bush hole 182A of the installed bush 182 and the control shaft hole 121A formed in the control shaft 121 are arranged in series is set. Then, connect pins 181 are inserted into these holes from the outside, and are fitted into the control shaft holes 121A. At this time, one end of the connect pin 181 is fitted in the control shaft hole 121A as much as possible, and the other end is arranged in the circumferential groove 145 inside the slider 140.

  By combining the control shaft 121 and the gear assembly 130 in this way, when the input arm 151 rotates by receiving a force from the cam, the slider 140 that meshes with the helical gear rotates in conjunction with the input arm 151. At the same time, the output arm 156 that meshes with the slider 140 through the helical gear also rotates, and the engine valve is opened by the rotation of the output arm 156.

On the other hand, when the connecting pin 181 and the bush 182 move in the axial direction together with the control shaft 121 by driving the actuator, the slider 140 is pushed in the axial direction by the connecting pin 181 and the bush 182, so that the control shaft 121 and the slider 140 are interlocked. And move in the axial direction. At this time, as the slider 140 moves in the axial direction, the input arm 151 and the output arm 156 rotate in opposite directions with respect to the slider 140. As the input arm 151 and the output arm 156 rotate relative to each other, the engine valve opening timing and the valve lift amount are changed.
JP 2007-291964 A

  By the way, when manufacturing this variable valve mechanism, as described above, the arm hole 151A, the slider hole 141A, the rocker shaft hole 122A, the bush hole 182A, and the control shaft hole 121A are connected in series before the connection pin 181 is attached. It is necessary to set the pre-assembled state lined up. Before setting this state, it is necessary to place the bush 182 formed as a relatively small element in the circumferential groove 145 in order to place it in the circumferential groove 145 inside the slider 140.

  As described above, in the conventional variable valve mechanism, when assembling, the positions of the holes and the holes of the plurality of components are aligned to form one hole, and the connection pin 181 is inserted into the hole, Since it is essential to insert a bush 182 which is a small component, a reduction in work efficiency is inevitable. In Patent Document 1, work efficiency is improved by using a jig, but problems such as the need for a dedicated jig occur. Such a problem is not limited to the variable valve mechanism of the structure exemplified here, but similarly occurs if the control shaft and the slider are linked in the axial direction using a connect pin and a bush. You can get it.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a variable valve mechanism for an internal combustion engine having a structure capable of improving the efficiency of assembly work.

In the following, means for achieving the above object and its effects are described.
(1) The invention according to claim 1 is provided between the engine valve and the camshaft to change the opening and closing characteristics of the engine valve, and includes a movable shaft that moves in the axial direction, and the movable shaft. Includes an interlocking body inserted into its own shaft hole, and an opening / closing body provided outside the interlocking body, the interlocking body is allowed to rotate with respect to the movable shaft, and the axial direction is the movable shaft and the interlocking member. The movable shaft and the interlocking body are combined in such a manner that the body moves in conjunction with each other, the movement of the opening / closing body in the axial direction with respect to the interlocking body is allowed, and the interlocking body is axially relative to the opening / closing body. The interlocking body and the opening / closing body are combined in such a manner that the interlocking body and the opening / closing body rotate relative to each other only when moving, and the movable shaft and the interlocking body move relative to the opening / closing body in the axial direction. In the variable valve mechanism for an internal combustion engine that changes the opening / closing characteristics of the engine valve by relative rotation between the interlocking body and the opening / closing body, the interlocking body is directed radially inward of the shaft hole on the inner peripheral side thereof. A protruding protrusion is provided, and the movable shaft is provided with a circumferential groove extending in the circumferential direction corresponding to the protrusion on the outer peripheral side thereof, and the movable shaft and the interlocking body are When the protrusion is fitted into the circumferential groove and the protrusion is allowed to move in the circumferential direction with respect to the circumferential groove, the interlocking body is allowed to rotate with respect to the movable shaft, and the circumferential The movement of the protrusion in the axial direction with respect to the circumferential groove is restricted through contact between the movable shaft portion forming the groove and the protrusion, so that the movable shaft and the interlocking body are in the axial direction. Is linked It is summarized in that is intended to dynamic.

  In this invention, the fitting of the circumferential groove of the movable shaft and the protrusion of the interlocking body allows the interlocking body to rotate with respect to the movable shaft and restricts the movement of the interlocking body in the axial direction relative to the movable body. Therefore, it is not necessary to use a connection auxiliary element such as a connect pin and a bush for the combination of the movable shaft and the interlocking body. As a result, when assembling the variable valve mechanism, work related to the connection auxiliary element that has been required in the past becomes unnecessary, so that the efficiency of assembling work of the mechanism can be improved.

  (2) The invention according to claim 2 is the variable valve mechanism of the internal combustion engine according to claim 1, wherein the movable shaft connects one end of the shaft and the circumferential groove on the outer peripheral side thereof. The gist is that a vertical groove is provided.

  According to this invention, when the movable shaft and the interlocking body are combined, it is possible to first fit the protrusion into the longitudinal groove, and then relatively move the movable shaft and the interlocking body in the axial direction to fit the protrusion into the circumferential groove. It becomes. As described above, the structure in which the protrusion is guided to the circumferential groove through the relative movement of the movable shaft and the interlocking body in the state where the protrusion is fitted in the vertical groove further improves the efficiency of the assembly work. Will be able to.

  (3) The invention according to claim 3 is the variable valve mechanism for the internal combustion engine according to claim 2, wherein the vertical groove is provided from one end to the other end of the movable shaft. Is the gist.

  According to this invention, the longitudinal groove of the movable shaft used for moving the interlocking body to the assembly position in the axial direction of the movable shaft has one end in the axial direction of the movable shaft as the starting point and the other end as the end point. . Therefore, when the protrusion of the interlocking body is engaged with the end of the movable shaft in accordance with the circumferential position of the longitudinal groove and moved to the assembly position in the axial direction of the movable shaft, the interlocking body is assembled in the axial direction of the movable shaft. It is possible to move to the attachment position from either end in the axial direction of the movable shaft.

  (4) The invention according to claim 4 is the variable valve mechanism for the internal combustion engine according to any one of claims 1 to 3, wherein the interlocking body is provided with a pair of the protrusions. The gist is that the pair of protrusions are provided in a manner facing each other through the center of the shaft hole in the circumferential direction of the interlocking body.

  According to the present invention, when the movable shaft and the interlocking body move in the axial direction, the movable shaft and the interlocking body are brought into contact with each other by the contact between the movable shaft and the interlocking body with a portion of the movable shaft that forms a circumferential groove. The relative movement of the body in the axial direction is regulated. Thereby, compared with the case where only one protrusion is provided, the force applied to each protrusion can be reduced.

  (5) The invention according to claim 5 is the variable valve mechanism for the internal combustion engine according to any one of claims 1 to 4, wherein the opening / closing body receives a force from a camshaft of the engine valve. The input unit and an output unit that opens the engine valve based on a force received by the input unit are configured. The interlocking body and the input unit are predetermined with respect to the axial direction of the movable shaft. The interlocking body and the output unit are engaged with each other via a helical gear inclined in a direction opposite to the predetermined direction with respect to the axial direction of the movable shaft. The variable valve mechanism is configured such that the input unit and the output unit move relative to the interlocking body as the movable shaft and the interlocking body move in the axial direction with respect to the input part and the output part. Each other Is summarized in that is to change the opening-closing characteristic of the engine valve than to rotate in opposite directions.

  1 to 16, an embodiment in which the variable valve mechanism for an internal combustion engine of the present invention is embodied as a variable valve mechanism for changing the opening / closing characteristics of an intake valve of an in-line four-cylinder internal combustion engine will be described. .

  As shown in FIG. 1, the engine 1 is configured by a combination of a cylinder block 11 and a cylinder head 12. In the cylinder block 11, four cylinders 11A are arranged in series. An air-fuel mixture of fuel injected into the intake port of the cylinder head 12 through the injector and air supplied to the intake port through the intake manifold is supplied to the combustion chamber of each cylinder 11A. The crankshaft is driven through the reciprocating motion of the piston by the fuel of the air-fuel mixture.

  The cylinder head 12 is provided with an intake valve 14 that opens and closes an intake port of each cylinder 11A with respect to the combustion chamber, and an exhaust valve 15 that opens and closes an exhaust port of each cylinder 11A with respect to the combustion chamber. Each intake valve 14 is opened through an intake cam 16 </ b> C provided on the intake camshaft 16. Each exhaust valve 15 is opened through an exhaust cam 17 </ b> C provided on the exhaust camshaft 17. The intake camshaft 16 and the exhaust camshaft 17 are supported by a cam carrier 13 formed integrally with the cylinder head 12. Moreover, it is driven by the torque of the crankshaft transmitted through the timing chain.

  The engine 1 is equipped with a variable valve mechanism 2 that can change the opening / closing characteristics of the intake valve 14, that is, the valve operating angle and the maximum valve lift amount of the intake valve 14. The variable valve mechanism 2 is provided at a position adjacent to the intake camshaft 16 in the cylinder head 12 so as to mediate transmission of force from the camshaft 16 to the intake valve 14. An actuator 61 that linearly moves the shaft 20 is connected to the control shaft 20 that is a component of the control shaft 20. Further, a shim 62 is provided between each gear assembly 30 provided on the control shaft 20 and the cam carrier 13 located on both sides of the gear assembly 30, and the gap between the gear assembly 30 and the cam carrier 13 is provided by the shim 62. Is buried. The valve operating angle indicates the rotation angle of the crankshaft during the period from when the intake valve 14 moves from the most closed position to the closed position again through the most opened position. The maximum valve lift amount indicates the lift amount of the intake valve 14 until the intake valve 14 moves from the most closed position to the most open position.

The outline of the structure of the variable valve mechanism 2 will be described with reference to FIGS.
As shown in FIG. 2, the variable valve mechanism 2 is configured by a combination of a control shaft 20 connected to the actuator 61 and a plurality of gear assemblies 30 provided on the control shaft 20 corresponding to each cylinder 11A. Has been. The constituent elements are combined so that the axis of the control shaft 20 and the axis of the gear assembly 30 are aligned.

  As shown in FIGS. 3 and 4, the gear assembly 30 includes a slider 40 that moves in the axial direction in conjunction with the control shaft 20, and an arm assembly 50 that meshes with the slider 40 through a helical gear on the outer periphery of the slider 40. It is comprised by the combination. The control shaft 20 and the gear assembly 30 are combined by inserting the control shaft 20 into the shaft hole 44 of the slider 40. Further, a protrusion 43 is fitted on the inner peripheral side of the slider 40 with respect to the circumferential groove 23 provided on the outer peripheral side of the control shaft 20. The protrusion 43 is allowed to move in the circumferential direction on the circumferential groove 23. On the other hand, in the axial direction, the movement of the protrusion 43 is restricted by the portion of the control shaft 20 that forms the circumferential groove 23.

  The arm assembly 50 includes an input arm 51 that receives a force from the intake camshaft 16 and an output arm 56 that transmits the force received by the input arm 51 to the intake valve 14. The arm assembly 50 is fixed in an axial position with respect to the cylinder head 12 by a cam carrier 13 and a shim 62 (see FIG. 1). Thereby, when the control shaft 20 moves in the axial direction with respect to the cylinder head 12, the slider 40 moves in conjunction with the control shaft 20, while the arm assembly 50 does not move with respect to the cylinder head 12.

  In the variable valve mechanism 2, the fitting of the protrusion 43 and the circumferential groove 23 allows the rotation of the slider 40 relative to the control shaft 20 and disables the movement of the slider 40 relative to the control shaft 20. Yes. Thereby, when the control shaft 20 moves in the axial direction, the protrusion 43 of the slider 40 is pushed against the wall of the circumferential groove 23 of the control shaft 20, so that the slider 40 also moves in conjunction with the axial direction. .

That is, the operation of the three components of the control shaft 20, the slider 40, and the arm assembly 50 constituting the variable valve mechanism 2 is permitted or restricted as follows. In this embodiment, the movement in the circumferential direction of each component at the axial center is defined as rotational movement, and the movement in the axial direction is defined as linear movement.
(A) The control shaft 20 cannot rotate but can move linearly.
(B) The slider 40 can be rotated and linearly moved.
(C) The arm assembly 50 can rotate but cannot linearly move.

The detailed structure of the slider 40 will be described with reference to FIGS.
The slider 40 has a cylindrical shape, and a shaft hole 44 for inserting the control shaft 20 is formed therein. Two types of helical gears, that is, a slider input gear 41 and a slider output gear 42 are formed on the outer periphery. The slider input gear 41 and the slider output gear 42 are formed so that the twisting direction of the teeth is opposite to the center axis of the slider 40.

  Inside the slider 40, a protrusion 43 that fits into the circumferential groove 23 of the control shaft 20 is provided so as to be integrated with a cylindrical portion that is a main body of the slider 40. The protrusions 43 are formed at two positions on the inner periphery of the slider 40 at positions facing the shaft center in a manner of protruding toward the shaft center.

The structure of the gear assembly 30 and the arm assembly 50 will be described with reference to FIGS.
As shown in FIG. 7, the gear assembly 30 is obtained by assembling an arm assembly 50 on the outer periphery of the slider 40. The arm assembly 50 includes one input arm 51 and two output arms 56, and the output arm 56 is set in contact with both sides of the input arm 51.

  As shown in FIG. 8, an input arm gear 54 that is an internal helical gear that meshes with the slider input gear 41 of the slider 40 is formed inside the input arm 51. Further, an input portion 52 that contacts the intake cam 16C of the intake camshaft 16 is provided. A support 53 to which the return spring 55 is attached is provided. In the engine 1, a return spring 55 is attached between the cylinder head 12 and the support portion 53 so that the input arm 51 is always pushed to the intake camshaft 16 side through the return spring 55.

  An output arm gear 58 that is an internal helical gear that meshes with the slider output gear 42 is formed inside the output arm 56. The output arm 56 is provided with an output portion 57 that contacts the roller rocker arm 18.

  The input arm gear 54, the slider input gear 41, the output arm gear 58, and the slider output gear 42 constitute the gear assembly 30 by meshing the corresponding helical gears.

The structure of the control shaft 20 will be described with reference to FIG.
The control shaft 20 continues on the outer periphery at a position where the gear assembly 30 is attached on the outer periphery of the main body (hereinafter, “control shaft main body 21”), specifically, at a position corresponding to the protrusion 43 of the slider 40. A circumferential groove 23 having a shape is formed. The width and depth of the circumferential groove 23 are formed corresponding to the width and height of the protrusion 43. Thus, in a state where the protrusion 43 of the slider 40 is fitted in the circumferential groove 23, the protrusion 43 is allowed to move in the circumferential direction with respect to the circumferential groove 23. That is, the slider 40 is allowed to move to the outer periphery of the control shaft 20. Rotating motion above is allowed.

  In addition to the circumferential groove 23, the control shaft 20 is formed with a pair of longitudinal grooves 22 extending from one end to the other end of the shaft 20 in a manner parallel to the central axis. These longitudinal grooves 22 are formed on the outer periphery of the control shaft 20 at positions facing the central axis. The width and depth are set to correspond to the width and height of the protrusion 43 of the slider 40. Accordingly, in a state where each protrusion 43 of the slider 40 is fitted in the corresponding vertical groove 22, the protrusion 43 is allowed to move in the axial direction with respect to the vertical groove 22, that is, the slider 40 is controlled by the control shaft. A linear movement on the outer circumference of 20 is allowed.

With reference to FIG. 10, the operation | movement aspect of the arm assembly 50 is demonstrated.
In the variable valve mechanism 2, the gear assembly 30 rotates around the control shaft 20 when a force pushing the input unit 52 in the circumferential direction is applied to the input unit 52. That is, the input arm 51, the slider 40, and the output arm 56 are integrally rotated with respect to the control shaft 20. For example, when the input portion 52 is pushed by the intake cam 16C when the operation state of the variable valve mechanism 2 is the operation state shown in FIG. 10A, the rotational movement of the slider 40, the input arm 51, and the output arm 56 is performed. Then, the operating state of the variable valve mechanism 2 shifts to the operating state shown in FIG.

With reference to FIG. 11, the operation | movement aspect of the variable valve mechanism 2 accompanying the linear motion of the control shaft 20 is demonstrated.
In the variable valve mechanism 2, the slider 40 moves in conjunction with the control shaft 20, and the arm assembly 50 cannot be moved in the axial direction, so that the control shaft 20 is moved in the axial direction. The position of the slider 40 in the axial direction with respect to the arm assembly 50 is changed. At this time, the meshing engagement of the helical gears imparts torsional forces acting in opposite directions to the input arm 51 and the output arm 56, so that the input arm 51 and the output arm 56 move in opposite directions with respect to the axis. Rotate. Thereby, the relative rotational phase of the input part 52 and the output part 57 around the control shaft 20 is changed.

  In the variable valve mechanism 2, since the slider 40 corresponding to each cylinder 11 </ b> A is assembled to one common control shaft 20, as the control shaft 20 moves, all the gear assemblies 30 are connected to the input unit 52. The relative rotation phase with the output unit 57 is changed.

The gear assembly 30 operates as follows according to the moving direction of the control shaft 20.
(A) When the control shaft 20 is linearly moved, a portion of the input portion 52 that is in contact with the intake camshaft 16 around the control shaft 20 due to the relative rotation of the input arm 51 and the output arm 56 (the input portion in the figure). 52 (hereinafter referred to as the input surface) and a portion of the output portion 57 that contacts the roller rocker arm 18 (in the figure, the lower surface of the output portion 57; hereinafter referred to as the output surface) approaches ("state a" Is equivalent to a change from "state b"). When the control shaft 20 is moved to the maximum extent, the distance between the input surface of the input portion 52 and the output surface of the output portion 57 around the control shaft 20 is the smallest.
(B) When the control shaft 20 is linearly moved in the direction opposite to that of (1), the intake camshaft 16 of the input portion 52 is rotated around the control shaft 20 by the relative rotation of the input arm 51 and the output arm 56. Is separated from the output surface of the output unit 57 (corresponding to a change from “state a” to “state c”). When the control shaft 20 is moved to the maximum, the distance between the input surface of the input portion 52 and the output surface of the output portion 57 around the control shaft 20 is the largest.

  The relationship between the operation of the variable valve mechanism 2, the valve operating angle of the intake valve 14, and the maximum valve lift will be described with reference to FIGS. 12 and 13 show a cross-sectional structure of the engine 1 around the intake valve 14 in a state where the control shaft 20 has moved to the maximum in the opposite direction with respect to the actuator 61.

With reference to FIG.12 and FIG.13, the opening / closing aspect of the intake valve 14 by the gear assembly 30 is demonstrated.
In the cylinder head 12, a gear assembly 30 of the variable valve mechanism 2 is disposed between the intake camshaft 16 and the roller rocker arm 18. The roller rocker arm 18 has one end (oscillating side end 18B) pushed toward the gear assembly 30 through the valve spring 18D of the intake valve 14 and the other end (support side end 18C) rushed. Since it is supported through the adjuster 19, the roller 18 </ b> A is always kept in contact with the output arm 56 of the gear assembly 30. Since the input arm 51 is pushed toward the intake camshaft 16 by a return spring 55 attached between the cylinder head 12 and the support portion 53, the input portion 52 is always held in contact with the intake cam 16C. The

  In the engine 1, the intake valve 14 is opened by pushing down the swing side end 18 </ b> B of the roller rocker arm 18 through the output portion 57 of the gear assembly 30. Further, the intake valve 14 is opened by pushing up the position (end position) of the swing side end 18B of the roller rocker arm 18 through the valve spring 18D. That is, as the rotational phase (gear rotational phase) of the gear assembly 30 with respect to the control shaft 20 changes, the position (end position) of the swing side end portion 18B of the roller rocker arm 18 with respect to the gear assembly 30 is changed. The valve 14 is opened and closed.

  The gear rotation phase is changed according to the contact position of the intake cam 16 </ b> C with the input unit 52. That is, the phase when the base circle of the intake cam 16C is in contact with the input unit 52 (basic rotational phase (FIGS. 12A and 13A)), the cam nose of the intake cam 16C and the input unit 52 And the phase at the time of contact (maximum rotation phase (FIG. 12B and FIG. 13B)).

  The end position is changed according to the contact position of the output unit 57 with respect to the roller rocker arm 18. That is, the position when the gear rotation phase is the basic rotation phase (basic phase position (FIGS. 12A and 13A)) and the position when the gear rotation phase is the maximum rotation phase (basic phase position). (FIG. 12B and FIG. 13B)). Further, the position at the maximum phase is a position when the output unit 57 and the rocker arm are in contact with each other according to the distance between the input unit 52 and the output unit 57 around the control shaft 20 (maximum pressed position (FIG. 12B)). ) And the maximum push-up position (FIG. 13B) The maximum push-down position indicates a position where the swing side end portion 18B of the roller rocker arm 18 is pushed down to the intake valve 14 side to the maximum. The maximum push-up position indicates a position where the swinging side end portion 18B of the roller rocker arm 18 is pushed down to the gear assembly 30. The distance between the input portion 52 and the output portion 57 around the control shaft 20 is as follows. Because it is changed by the movement of the control shaft 20, when the position of the control shaft 20 is kept constant, Aitoki position is also maintained in a fixed position. Further, when the end position is located at the maximum push-up position and the basic phase, the intake valve 14 irrespective of the gear rotation phase is maintained in a closed state.

  In the engine 1, the valve operating angle is determined by the rotation angle of the crankshaft during the period in which the swing side end 18 </ b> B (intake valve 14) of the roller rocker arm 18 is pushed down by the output unit 57, that is, the end position of the roller rocker arm 18. From the basic phase position (state shown in FIG. 12 (a)) to the basic phase position (state shown in FIG. 12 (a)) again through the maximum phase position (state shown in FIG. 12 (b)). This corresponds to the rotation angle of the crankshaft during the period. The maximum valve lift amount is the lift amount when the swing side end 18B (intake valve 14) of the roller rocker arm 18 is pushed down to the maximum by the output unit 57, that is, the gear rotation phase is the maximum rotation phase (see FIG. 12 (b) state).

  For this reason, the valve operating angle and the maximum valve lift amount increase as the maximum phase position of the roller rocker arm 18 approaches the maximum pressing position, and decrease as the maximum phase position approaches the maximum pressing position. Accordingly, the distance between the input section 52 and the output section 57 around the control shaft 20 (the difference in relative rotational phase between the input section 52 and the output section 57) is changed through the movement of the control shaft 20 in the axial direction. As a result, the valve operating angle and the maximum valve lift amount are changed. The valve operating angle and the maximum valve lift amount change as follows according to the operation of the control shaft 20.

  (A) When the control shaft 20 moves in a direction to reduce the difference in rotational phase between the input unit 52 and the output unit 57 around the control shaft 20 (when transitioning from “state a” to “state b” in FIG. 11) As the distance between the input unit 52 and the output unit 57 becomes narrow, the position at the maximum phase approaches the maximum push-up position, so that the valve operating angle and the maximum valve lift amount change in a decreasing direction. When the control shaft 20 moves to the maximum in the direction of reducing the difference in rotational phase between the input portion 52 and the output portion 57, the valve operating angle and the maximum valve lift amount are within the range that can be changed through the variable valve mechanism 2. Each is set to the lower limit maximum valve lift.

  (B) When the control shaft 20 moves in the direction of increasing the rotational phase difference between the input unit 52 and the output unit 57 around the control shaft 20 (when the state transitions from “state a” to “state c” in FIG. 11) In other words, when the interval between the input unit 52 and the output unit 57 is widened, the maximum phase position approaches the maximum pressed position, so that the valve operating angle and the maximum valve lift amount change in the increasing direction. When the control shaft 20 moves to the maximum in the direction that increases the difference in rotational phase between the input unit 52 and the output unit 57, the valve operating angle and the maximum valve lift amount are within the range that can be changed through the variable valve mechanism 2. Each is set to the upper limit maximum valve lift.

With reference to FIGS. 14-16, the manufacturing method of the variable valve mechanism 2 is demonstrated.
In the manufacturing method, the variable valve mechanism 2 is manufactured in the following order. That is, each component of the variable valve mechanism 2 is manufactured in the first step, and these are assembled in the second step to complete the variable valve mechanism 2.

  [First Step] In this step, each component other than the slider 40 of the variable valve mechanism 2 is manufactured through a method suitable for each, and the slider 40 is manufactured in the following manner, whereby the variable valve mechanism is manufactured. Prepare all the components necessary for the assembly of 2.

  For manufacturing the slider 40, first, a cylindrical member as a material of the slider is prepared, and the slider input gear 41, the slider output gear 42, and the like are processed on the outer peripheral surface by sequential cutting or rolling. As an example of the processing order, (1) a step of rolling the slider output gear 42 on the outer periphery of the material member, (2) a step of setting the axis center of the material member, and (3) a step of forming the outer peripheral surface by lathe processing (4) a step of rolling the slider input gear 41, (5) a step of forming a slider internal hole, (6) a step of chamfering the gear, (7) a step of cleaning the slider, and (8) For example, the steps may be performed in the order of increasing the strength by gas soft nitriding.

With reference to FIG. 14, the procedure of the “(5) step of forming the slider internal hole” will be described in detail.
First, a basic slider 40A shown in FIG. 14A, that is, a basic slider 40A that is a cylindrical material member that has been subjected to the respective processes according to the steps (1) to (4) is prepared. The basic slider 40A is provided with center portions 40C on both end faces through the step (2).

  Next, as shown in FIG. 14B, the tip 71A of the drill 71 is set with respect to one center portion 40C of the foundation slider 40A, and the drill 71 is moved along the center axis of the foundation slider 40A. To form a hole. Specifically, the drill 71 is moved until the boundary between the tip 71A of the drill 71 and the main body 71B substantially coincides with the end of the slider input gear 41 in the radial direction of the basic slider 40A.

  Next, as shown in FIG. 14 (c), the other end surface of the basic slider 40A is processed in the same manner as the processing on the one end surface, whereby a hole extending from one end surface to the center, and The base slider 40A is formed in a state in which holes extending from the other end surface to the center and walls separating these holes are provided. The diameter of the main body 71B of the drill 71, that is, the diameter of the hole formed in the basic slider 40A corresponds to the outer diameter of the control shaft main body 21.

Next, as shown in FIG. 14 (d), a drill 72 having a smaller diameter than the drill 71 is set in the wall between the pair of holes, and an internal hole is formed through the wall by the drill 72. .
Next, as shown in FIGS. 14E and 14F, both sides of the wall between the pair of holes are cut by the end mill 73 to adjust the shape of the pair of holes.

  Through these steps, a basic slider 40A having the shape shown in FIG. 14G is formed. Then, the machining shown in FIG. 14H is performed on the basic slider 40A, that is, the machining center 74 is in the order of the arrows in the drawing so that two opposing portions of the wall remain as a pair of protrusions 43. Perform cutting with. Then, the basic slider 40A subjected to the above processing is used as a slider 40 similar to that shown in FIGS. 5 and 6 in the subsequent assembly process.

[Second Step] In this step, the gear assembly 30 shown in FIGS. 7 and 8 is assembled and attached to the control shaft 20 shown in FIG.
Specifically, first, the input arm 51 and the output arm 56 are assembled to the slider 40 manufactured in the first step, and thereby the gear assembly 30 is assembled.

  Next, the four gear assemblies 30 are arranged so that the control shaft 20 can be inserted into the four gear assemblies 30 at a time. Specifically, the interval between adjacent gear assemblies 30 is set to the same size as the interval between adjacent circumferential grooves 23 on the control shaft 20, the central axes of the sliders 40 are matched, and The posture of the gear assembly 30 is set to be the same. The control shaft 20 is sequentially inserted into the shaft hole 44 of the slider 40 of each gear assembly 30 arranged in this way.

  At this time, as shown in FIG. 15, the position of each vertical groove 22 of the control shaft 20 is aligned with the protrusion 43 of the slider 40, and then the control shaft 20 is moved in the axial direction with respect to the gear assembly 30. Accordingly, the protrusion 43 of the slider 40 relatively moves on the longitudinal groove 22 as the control shaft 20 moves in the axial direction. Then, the shaft 20 is moved until the protrusion 43 of the slider 40 coincides with the circumferential groove 23 of the control shaft 20.

  Next, as shown in FIG. 16, the control shaft 20 is rotated in the circumferential direction with respect to each gear assembly 30 to change the relative rotational phase between the protrusion 43 and the longitudinal groove 22. As the rotation phase is changed, the protrusion 43 is sandwiched between the portions of the control shaft 20 that form the circumferential groove 23, so that the relative movement in the axial direction between each gear assembly 30 and the control shaft 20 is restricted. . Thus, the variable valve mechanism 2 including the plurality of gear assemblies 30 and the control shaft 20 shown in FIGS. 3 and 4 is assembled.

  In the engine 1 on which the variable valve mechanism 2 is mounted, as described above, the shim 62 is provided between each gear assembly 30 and the cam carrier 13, and the axial direction of the arm assembly 50 with respect to the cylinder head 12 is provided. Movement to is restricted. Since the slider 40 is engaged with the arm assembly 50 by each helical gear, the slider 40 does not move in the axial direction with respect to the arm assembly 50 unless the control shaft 20 moves in the axial direction. Therefore, even when the circumferential position of the protrusion 43 of the slider 40 and the longitudinal groove 22 of the control shaft 20 coincides with the driving of the variable valve mechanism 2 during the operation of the engine 1, the slider 40 moves to the control shaft 20. On the other hand, it is possible to suppress the situation of moving in the axial direction.

  When the control valve 20 is rotated with respect to each gear assembly 30 during assembly of the variable valve mechanism 2 (see FIG. 16), the relative rotation phase of these is as the relative valve phase when the variable valve mechanism 2 is driven. A rotational phase is set at which the protrusion 43 and the longitudinal groove 22 are less likely to coincide with each other in the circumferential direction. In order to avoid the occurrence of such position matching, for example, when the variable valve mechanism 2 is driven, the range in which the slider 40 rotates with respect to the control shaft 20 is limited, that is, the range in which the position matching does not occur. Only the rotation of the slider 40 can be allowed. As a configuration for limiting the rotation range, for example, only one protrusion 43 of the slider 40 and one longitudinal groove 22 of the control shaft 20 are provided, and then the relative relationship between the control shaft 20 and each gear assembly 30 at the time of assembly is set. There is one that sets the rotation phase to a rotation phase at which the above-mentioned coincidence hardly occurs. Other configurations include a stopper provided to limit the rotation range of the slider 40.

[Effect of the embodiment]
As described above in detail, according to the variable valve mechanism of the internal combustion engine of the present embodiment, the following effects can be obtained.

  (1) In the variable valve mechanism of the internal combustion engine of the present embodiment, the rotation of the slider 40 relative to the control shaft 20 is allowed by fitting the circumferential groove 23 of the control shaft 20 and the protrusion 43 of the slider 40, and The movement of the slider 40 in the axial direction relative to the slider 40 is restricted. For this reason, it is not necessary to use a connection auxiliary element such as a connect pin and a bush for the combination of the control shaft 20 and the slider 40. As a result, when assembling the variable valve mechanism 2, work related to the connection auxiliary element that has been conventionally required is not required, and the efficiency of assembling work of the mechanism can be improved.

  (2) In the variable valve mechanism of the internal combustion engine of the present embodiment, when the control shaft 20 and the slider 40 are combined, first, the protrusion 43 is fitted into the longitudinal groove 22, and then the control shaft 20 and the slider 40 are moved in the axial direction. The protrusion 43 can be fitted into the circumferential groove 23 by relative movement. As described above, the structure in which the protrusion 43 is guided to the circumferential groove 23 through the relative movement of the control shaft 20 and the slider 40 in a state where the protrusion 43 is fitted in the vertical groove 22 is adopted. The efficiency can be further improved.

  (3) In the variable valve mechanism of the internal combustion engine of the present embodiment, the vertical groove of the control shaft 20 used for moving the slider 40 to the assembly position in the axial direction of the control shaft 20 is the axial direction of the control shaft 20. One end of is the start point, and the other end is the end point. Therefore, when the protrusion 43 of the slider 40 is engaged with the end of the control shaft 20 in accordance with the circumferential position of the longitudinal groove 22 and moved to the assembly position in the axial direction of the control shaft 20, the slider 40 is moved to the control shaft 20. It is possible to move from either end in the axial direction of the control shaft 20 to the assembly position in the axial direction.

  (4) In the variable valve mechanism of the internal combustion engine of the present embodiment, when the control shaft 20 and the slider 40 move in the axial direction, one protrusion 43 and the circumferential groove 23 are formed between the control shaft 20 and the slider 40. The relative movement in the axial direction of the control shaft 20 and the slider 40 is regulated by the contact with the portion of the control shaft 20 formed. Thereby, compared with the case where only one protrusion 43 is provided, the force applied to each protrusion 43 can be reduced.

(Other embodiments)
The embodiment of the present invention is not limited to the above-described embodiment, and can be carried out, for example, in the following manner.

  In the above embodiment, the protrusions 43 of the slider 40 are formed at two positions facing each other. However, this may be one, or three or more at an equal angle position, or a plurality of positions at an uneven position. can do. However, in any case, in order to guide the protrusion to the set position of the control shaft 20, it is necessary to set a vertical groove at a position facing the protrusion on the control shaft 20 in the circumferential direction. Further, the shape of the protrusion is not limited to that of the above embodiment, and can be implemented. However, in this case, it is necessary to change the vertical groove and the circumferential groove of the control shaft 20 according to the shape of the protrusion.

  In short, at the stage of combining the control shaft 20 and the slider 40 in manufacturing the variable valve mechanism 2, the control shaft 20 is fitted by fitting the protrusion integrated with the slider 40 and the corresponding groove of the control shaft 20. As long as the slider 40 can be interlocked, the shape of the protrusion of the slider 40 and the groove of the control shaft 20 can be changed as appropriate. Therefore, it is also possible to employ a projecting portion of the slider 40 that is separate from the main body of the slider 40. In this case, before the control shaft 20 and the slider 40 are combined, the slider 40 and the control shaft 20 are combined with the main body of the slider 40 and a separate protrusion to form an integrated slider 40. Can be manufactured in the same manner by combining them in a manner according to the above embodiment.

  In the above embodiment, the slider 40 is manufactured by sequentially processing the cylindrical member. However, this may be replaced by the above embodiment as long as it is a processing method capable of forming a protrusion inside the slider 40. Two specific manufacturing methods will be described below as specific examples.

  (1) A cylindrical member is prepared in the same manner as in the “first step” of the above embodiment, and gear processing is performed on the outer periphery, and a hole having a diameter matching the maximum diameter of the control shaft 20 is provided in the axial direction in the inside. Process it. This hole always has the same diameter from one end to the other. Further, a recess is formed in the projecting portion. Here, the slider 40 having a necessary shape can be manufactured by setting the protrusion formed as a separate member in the recessed portion inside the hole and fixing it by a method such as press-fitting or joining. With this manufacturing method, the gas soft nitrogenization treatment for obtaining wear resistance on the member may be performed only on the protrusions.

  (2) A cylindrical member having a protrusion 43 at its inner diameter and having a flat outer periphery is formed by forging. The slider 40 having a required shape can be manufactured by press-fitting the slider input gear 41 and the slider output gear 42 formed as separate members on the outer periphery of the cylindrical member. In addition, if it is this manufacturing method, the gas soft-nitrogenation process for obtaining abrasion resistance to a member should just be given only to the forge member provided with a protrusion.

  In the above embodiment, the longitudinal groove 22 of the control shaft 20 used for moving the gear assembly 30 to the assembly position in the axial direction of the control shaft 20 starts from one end in the axial direction of the control shaft 20 and the other end However, it may not be continuous from one end to the other end. For example, the end point can be set to the circumferential groove 23 farthest from the start point side. In this case, when the control shaft 20 is inserted into the inner hole of the gear assembly 30, the control shaft 20 is inserted into the shaft hole of the slider 40 of the gear assembly 30 from the start point side of the vertical groove 22.

  In the above embodiment, the gear assembly 30 can be guided to the set position on the control shaft 20 by forming the vertical groove 22 in the control shaft 20. However, for example, the slider 40 or the gear assembly 30 as a whole can be divided in the axial direction, and each of the divisions of the slider 40 or the gear assembly 30 is set so that the protrusion 43 is fitted in the circumferential groove 23 of the control shaft 20. An assembly method such as connecting elements is also conceivable.

In the above embodiment, the present invention is implemented as the variable valve mechanism 2 of the intake valve 14, but the present invention can also be implemented as a variable valve mechanism of the exhaust valve 15.
The structure of the variable valve mechanism for carrying out the present invention is not limited to the structure exemplified in the above embodiment. In short, a control shaft that moves in the axial direction, a slider that moves in the axial direction in conjunction with the shaft, and an arm assembly that is provided outside the slider are provided, and the control shaft and the slider and the arm assembly move in the axial direction. The present invention can be applied to any variable valve mechanism as long as the valve opening / closing special characteristics are changed with the relative movement.

The top view which shows the planar structure of the engine which mounts the mechanism about one Embodiment which actualized the variable valve mechanism of the internal combustion engine of this invention. The perspective view which shows the perspective structure about the variable valve mechanism of the embodiment. (A) The perspective view which shows the one part perspective structure about the control shaft and gear assembly which comprise the variable valve mechanism of the embodiment. (B) The top view which shows the one part planar structure about the control shaft and a gear assembly. (A) The fragmentary sectional view which shows the cross-section along the DA-DA line of FIG.3 (b) about the control shaft and gear assembly of the embodiment. (B) Sectional drawing which shows the cross-sectional structure which followed the DB-DB line | wire of FIG.3 (b) about the control shaft and a gear assembly. (A) The perspective view which shows the perspective structure about the slider which comprises the variable valve mechanism of the embodiment. (B) The top view which shows the planar structure about the slider. (A) Sectional drawing which shows the cross-section along the DC-DC line | wire of FIG.5 (b) about the slider of the embodiment. (B) Sectional drawing which shows the cross-section along the DD-DD line of FIG.5 (b) about the slider. (C) Sectional drawing which shows the cross-section along the DE-DE line | wire of FIG.5 (b) about the slider. (A) The perspective view which shows the perspective structure about the gear assembly which comprises the variable valve mechanism of the embodiment. (B) The top view which shows the planar structure about the gear assembly. (A) Sectional drawing which shows the cross-section along the DF-DF line of FIG.8 (b) about the gear assembly which comprises the variable valve mechanism of the embodiment. (B) Sectional drawing which shows the cross-sectional structure along the DG-DG line | wire of FIG.8 (b) about the gear assembly. (A) The front view which shows the front structure about the control shaft which comprises the variable valve mechanism of the embodiment. (B) Sectional drawing which shows the cross-section along a DH-DH line about the control shaft. (C) Sectional drawing which shows the cross-section along a DI-DI line | wire about the control shaft. (A) The side view which shows a side structure when the base circle of a cam is contacting the input arm about the variable valve mechanism of the embodiment. (B) The side view which shows a side structure when the cam nose is contacting the input arm about the variable valve mechanism. The side view which shows the side structure about the variable valve mechanism of the embodiment. Sectional drawing which shows the cross-section around the intake valve about the engine carrying the variable valve mechanism of the embodiment. Sectional drawing which shows the cross-section around the intake valve about the engine carrying the variable valve mechanism of the embodiment. The process figure which shows the operation | work aspect of the process at the time of the slider manufacture about the variable valve mechanism of the embodiment. Process drawing which shows the operation | work aspect of 1 process at the time of the assembly | attachment about the variable valve mechanism of the embodiment. Process drawing which shows the operation | work aspect of 1 process at the time of the assembly | attachment about the variable valve mechanism of the embodiment. The perspective view which shows the perspective structure about the conventional variable valve mechanism. (A) About the conventional variable valve mechanism, the fragmentary sectional view which shows the one part cross-section. (B) The perspective view which shows the perspective structure of the state which removed the part about the conventional variable valve mechanism.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Engine, 11 ... Cylinder block, 11A ... Cylinder, 12 ... Cylinder head, 13 ... Cam carrier, 14 ... Intake valve, 15 ... Exhaust valve, 16 ... Intake camshaft, 16C ... Intake cam, 17 ... Exhaust camshaft, 17C ... Exhaust cam, 18 ... Roller rocker arm, 18A ... Roller, 18B ... Oscillating side end, 18C ... Support side end, 18D ... Valve spring, 19 ... Rush adjuster, 2 ... Variable valve mechanism, 20 ... Control shaft 21 ... Control shaft body, 22 ... Vertical groove, 23 ... Circumferential groove, 30 ... Gear assembly, 40 ... Slider, 40A ... Basic slider, 40C ... Center portion, 41 ... Slider input gear, 42 ... Slider output gear, 43 ... Projection, 44 ... shaft hole, 50 ... arm assembly, 51 ... input arm, 52 ... input section, 5 ... support part, 54 ... input arm gear, 55 ... return spring, 56 ... output arm, 57 ... output part, 58 ... output arm gear, 61 ... actuator, 62 ... shim, 71 ... drill, 71A ... tip part, 71B ... main body part 72 ... Drill, 73 ... End mill, 74 machining center.

Claims (5)

An opening / closing characteristic of the engine valve provided between the engine valve and the camshaft, wherein the movable shaft moves in the axial direction, and an interlocking body in which the movable shaft is inserted into its own shaft hole, An open / close body provided outside the interlocking body, wherein the interlocking body is allowed to rotate with respect to the movable shaft, and the movable shaft and the interlocking body move in conjunction with each other in the axial direction. And the interlocking body, the movement of the opening / closing body in the axial direction with respect to the interlocking body is allowed, and the interlocking body and the opening / closing body only when the interlocking body moves in the axial direction with respect to the opening / closing body. The interlocking body and the opening / closing body are combined in such a manner that the interlocking body and the opening / closing body are rotated relative to each other. The variable valve mechanism for an internal combustion engine that changes an opening-closing characteristic of the engine valve from rolling,
The interlocking body is provided with a protrusion protruding toward the radially inner side of the shaft hole on the inner peripheral side thereof,
The movable shaft is provided with a circumferential groove extending in the circumferential direction corresponding to the protrusion on the outer peripheral side thereof,
The movable shaft and the interlocking body are in a state in which the protrusion is fitted into the circumferential groove and movement of the protrusion in the circumferential direction with respect to the circumferential groove is allowed, so that the interlocking body with respect to the movable shaft And the movement of the protrusion in the axial direction with respect to the circumferential groove is restricted through contact between the portion of the movable shaft forming the circumferential groove and the protrusion. A variable valve mechanism for an internal combustion engine, characterized in that the movable shaft and the interlocking body move in conjunction with each other. The variable valve mechanism for an internal combustion engine according to claim 1,
A variable valve mechanism for an internal combustion engine, wherein the movable shaft is provided with a longitudinal groove connecting one end portion of the shaft and the circumferential groove on an outer peripheral side thereof. The variable valve mechanism for an internal combustion engine according to claim 2,
The variable groove mechanism for an internal combustion engine, wherein the longitudinal groove is provided from one end portion to the other end portion of the movable shaft. In the variable valve mechanism of the internal combustion engine according to any one of claims 1 to 3,
The interlocking body is provided with a pair of protrusions, and the pair of protrusions are provided in a manner facing each other through the center of the shaft hole in the circumferential direction of the interlocking body. A variable valve mechanism for an internal combustion engine. The variable valve mechanism for an internal combustion engine according to any one of claims 1 to 4,
The opening / closing body includes an input part that receives a force from the camshaft of the engine valve, and an output part that opens the engine valve based on the force that the input part receives,
The interlocking body and the input unit are meshed via a helical gear inclined in a predetermined direction with respect to the axial direction of the movable shaft,
The interlocking body and the output unit are meshed with each other via a helical gear inclined in a direction opposite to the predetermined direction with respect to the axial direction of the movable shaft,
The variable valve mechanism is configured such that the input part and the output part rotate in opposite directions with respect to the interlocking body as the movable shaft and the interlocking body move in the axial direction with respect to the input part and the output part. Thus, the variable valve mechanism for an internal combustion engine is characterized by changing the opening / closing characteristics of the engine valve.

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