JP2013234601A - Variable valve apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a variable valve apparatus capable of suppressing wear of a cam piece or wear of a predetermined portion of an internal combustion engine to which the cam piece is pressed.SOLUTION: A variable valve apparatus (5) includes: a cam piece (20) having a plurality of cams (21, 22), moving in an axial direction of a camshaft (10) relative to the camshaft during the switching of the cams driving engine valves (100) and having a first slope (52) inclined relative to the axial direction and a second slope (53) connected to the first slope; and a pressure application member (40) for applying a pressure to the first slope after the completion of the switching of the cams driving the engine valves and applying a second pressure to the second slope during the switching of the cam. The first slope is inclined relative to the axial direction so that a direction of component of force obtained by decomposing the pressure received from the pressure application member after the completion of the switching of the cam into the axial direction becomes the direction of pressing the cam piece to predetermined portions (130, 131) of the internal combustion engine. The inclination angle of the first slope is smaller than that of the second slope.

Description

  The present invention relates to a variable valve operating device, and more particularly to a variable valve operating device used for an internal combustion engine.

  2. Description of the Related Art Conventionally, as a variable valve operating device, a cam switching type variable valve operating device that switches the type of cam that drives an engine valve of an internal combustion engine is known. As such a variable valve apparatus, for example, in Patent Document 1, a cam piece having cams with different cam profiles is arranged on a cam shaft, and the cam piece is moved in the axial direction of the cam shaft to switch the cam. Is disclosed.

JP 2005-42717 A

  A cam-switching type variable valve device as exemplified in Patent Document 1 holds the position of the cam piece in the axial direction with respect to the cam shaft by pressing the cam piece against a predetermined part of the internal combustion engine after the cam switching is completed. In such an improvement, the cam piece is pressed against a predetermined part of the internal combustion engine while rotating around the cam shaft. In this case, if the pressing force of the cam piece against the predetermined portion of the internal combustion engine is not appropriate, the wear of the predetermined portion of the cam piece or the internal combustion engine may be increased.

  An object of the present invention is to provide a variable valve operating apparatus that can suppress wear of a cam piece or wear of a predetermined portion of an internal combustion engine to which the cam piece is pressed.

  A variable valve operating apparatus according to the present invention has a plurality of cams as cams for driving an engine valve of an internal combustion engine, and the camshaft is axially moved with respect to the camshaft when the cam for driving the engine valve is switched. And a cam piece having a first inclined surface inclined with respect to the axial direction and a second inclined surface connected to the first inclined surface, and the first after the switching of the cam for driving the engine valve is completed. A pressure applying member that applies pressure to the inclined surface and applies pressure to the second inclined surface when the cam is switched, and the first inclined surface receives the pressure from the pressure applying member after the cam switching is completed. Is inclined with respect to the axial direction such that the direction of the component force obtained by disassembling the axial direction is the direction in which the cam piece is pressed against a predetermined part of the internal combustion engine, and the inclination angle of the first inclined surface is the second angle. Inclined surface Smaller than the inclination angle.

  According to the variable valve operating apparatus of the present invention, the cam piece can be pressed against a predetermined portion of the internal combustion engine after the cam switching is completed. Thus, the position of the cam piece in the axial direction relative to the cam shaft can be maintained after the cam switching is completed. Further, since the inclination angle of the first inclined surface is smaller than the inclination angle of the second inclined surface, the component force obtained by resolving the pressure applied from the pressure applying member to the first inclined surface in the axial direction after the cam switching is completed. The magnitude can be made smaller than the magnitude of the component force obtained by resolving the pressure applied from the pressure applying member to the second inclined surface during the cam switching in the axial direction. Thereby, compared with the case where the inclination angle of a 1st inclined surface is the same as the inclination angle of a 2nd inclined surface, the force which presses a cam piece against the predetermined part of an internal combustion engine after completion | finish of a cam switching can be made small. As a result, it is possible to suppress wear of the cam piece or wear of a predetermined portion of the internal combustion engine to which the cam piece is pressed.

  In the above configuration, the cam piece may include a groove having a groove direction inclined with respect to the axial direction, and the configuration may further include a groove engaging member that engages with the groove when the cam is switched. According to this configuration, the cam piece can be moved in the axial direction of the cam shaft by engaging the groove engaging member with the groove when the cam is switched.

  In the above configuration, the first inclined surface and the second inclined surface are formed in a recess provided in a surface of the cam piece that faces the cam shaft, and the pressure applying member includes the first inclined surface and the first inclined surface. A contact member that contacts the two inclined surfaces; and a biasing member that is disposed in a hole provided in the cam shaft and biases the contact member in a direction perpendicular to the axial direction of the cam shaft. It may be. According to this configuration, the pressure applying member can be accommodated inside the cam piece and the cam shaft. Thereby, the variable valve operating device can be made compact.

  In the above configuration, the predetermined portion of the internal combustion engine may be a cam cap. According to this configuration, the wear of the cam piece or the wear of the cam cap can be suppressed.

  ADVANTAGE OF THE INVENTION According to this invention, the variable valve apparatus which can suppress the abrasion of the predetermined part of the internal combustion engine in which the wear of a cam piece or a cam piece is pressed can be provided.

Fig.1 (a) is a schematic diagram which shows a variable valve apparatus. FIG.1 (b) is typical sectional drawing which shows the inside of a cam piece. FIG.1 (c) is typical sectional drawing for demonstrating the 1st recessed part and 2nd recessed part of a cam piece. FIG. 2 is a schematic diagram showing a state in which the cam piece has moved in the axial direction with respect to the cam shaft from the state of FIG. FIG. 3A is a schematic diagram for explaining the details of the groove. FIG. 3B to FIG. 3D are schematic views for explaining an engagement mode of the groove engaging member with the groove. 4 (a) to 4 (c) are schematic cross-sectional views for explaining the engagement relationship between the first inclined surface and the second inclined surface and the pressure applying member at the time of switching the cam and after the end of the switching. is there. FIG. 5A to FIG. 5C are schematic cross-sectional views for explaining details of the first inclined surface and the second inclined surface.

  Hereinafter, modes for carrying out the present invention will be described.

  A variable valve apparatus 5 according to Embodiment 1 of the present invention will be described. FIG. 1A is a schematic diagram showing the variable valve gear 5. The variable valve operating device 5 includes a cam shaft 10, a cam piece 20, and a groove engaging device 30. The cam piece 20 includes a plurality of cams (first cam 21 and second cam 22) and a groove forming portion 24 having a groove 23. The groove engaging device 30 includes a groove engaging member 31 and a drive unit 32. The variable valve gear 5 is provided in the internal combustion engine. The internal combustion engine includes an engine valve 100, a rocker arm 110, bearings (first bearing 120 and second bearing 121), and cam caps (first cam cap 130 and second cam cap 131). FIG. 1A schematically shows the variable valve gear 5 when the cam for driving the engine valve 100 is the second cam 22.

  In FIG. 1A, the left side is the right front wheel (Fr) side of the vehicle, and the right side is the right rear wheel (Rr) side. The variable valve operating apparatus 5 according to the present embodiment is provided in an internal combustion engine mounted on a vehicle such that one end side of the cam shaft 10 is located on the Fr side and the other end side of the cam shaft 10 is located on the Rr side. Yes. However, the arrangement of the variable valve gear 5 is not limited to the arrangement shown in FIG. 1A. For example, one end of the camshaft 10 is located on the left front wheel side, and the other end is on the left rear. An arrangement mode located on the ring side may be used, and other arrangement modes may be used.

  The cam shaft 10 is pivotally supported by the first bearing 120 and the second bearing 121. The first cam cap 130 is a cap for holding the cam shaft 10 on the first bearing 120. The second cam cap 131 is a cap for holding the cam shaft 10 on the second bearing 121. The camshaft 10 rotates about the axis 11 as a rotation center line when the power of the crankshaft of the internal combustion engine is transmitted by a power transmission member such as a belt. Hereinafter, the direction along the axis 11 of the cam shaft 10 is referred to as an axial direction. In FIG. 1A, the left-right direction is the axial direction of the cam shaft 10.

  The cam piece 20 is disposed on the cam shaft 10. Specifically, the cam piece 20 is disposed on the cam shaft 10 so as to be movable with respect to the cam shaft 10 in the axial direction of the cam shaft 10. The cam piece 20 according to the present embodiment receives a force from the groove engaging member 31 of the groove engaging device 30 in the axial direction of the cam shaft 10 with respect to the cam shaft 10 when the cam for driving the engine valve 100 is switched. Move.

  FIG. 2 schematically shows a state where the cam piece 20 moves in the axial direction with respect to the cam shaft 10 from the state of FIG. 1A and the cam for driving the engine valve 100 is switched to the first cam 21. ing. As shown in FIGS. 1A and 2, the cam piece 20 moves in the axial direction with respect to the cam shaft 10, so that the cam that drives the engine valve 100 can be switched. Specifically, the cam for driving the engine valve 100 can be switched between the first cam 21 (FIG. 2) and the second cam 22 (FIG. 1 (a)).

  Referring to FIG. 1A, the cam piece 20 is disposed on the cam shaft 10 so as not to rotate with respect to the cam shaft 10. Specifically, a spline 12 is formed on at least a portion of the camshaft 10 where the cam piece 20 slides, and a spline corresponding to the spline 12 is also formed on the inner peripheral surface of the camshaft 10 of the cam piece 20. With this configuration, when the cam shaft 10 rotates, the cam piece 20 can rotate integrally with the cam shaft 10, and the cam piece 20 moves relative to the cam shaft 10 in the axial direction of the cam shaft 10 when the cam is switched. Can move. The mechanism for preventing the cam piece 20 from rotating with respect to the cam shaft 10 while allowing the cam piece 20 to move in the axial direction with respect to the cam shaft 10 is not limited to the mechanism using the spline 12 as in this embodiment.

  The first cam 21 is disposed on the Fr side with respect to the second cam 22. The internal combustion engine according to the present embodiment includes two engine valves 100 in one cylinder. Therefore, two first cams 21 and two second cams 22 are provided for each cylinder so as to correspond to each engine valve 100. The groove forming portion 24 according to this embodiment includes a second cam 22 (Fr side second cam 22) corresponding to one engine valve 100 and a first cam 21 (Rr side first cam corresponding to the other engine valve 100). 1 cam 21). The groove 23 of the groove forming part 24 is formed on the outer peripheral surface of the groove forming part 24. Details of the groove 23 will be described later with reference to FIG.

  In this embodiment, the type of engine valve 100 driven by the first cam 21 and the second cam 22 (hereinafter, both may be collectively referred to as cams) is an intake valve. However, the type of the engine valve 100 is not limited to this, and may be an exhaust valve. The cam drives the engine valve 100 via the rocker arm 110. That is, the rocker arm 110 functions as a cam power transmission member that transmits cam power to the engine valve 100.

  The driving method of the engine valve 100 by the cam is not limited to the rocker arm driving method as in this embodiment. As another driving method of the engine valve 100 by the cam, various driving methods such as a direct-acting driving method can be used. When a direct drive system is used as the drive system of the engine valve 100 by the cam, a valve lifter can be used as the cam power transmission member. However, the configuration of the cam power transmission member is not limited to the rocker arm 110, the valve lifter, or the like as long as the cam power can be transmitted to the engine valve 100.

  The groove engaging device 30 is a device that moves the cam piece 20 in the axial direction when the cam is switched. The specific configuration of the groove engaging device 30 is not particularly limited as long as the cam piece 20 can be moved in the axial direction, but the groove engaging device 30 according to the present embodiment is described above. Thus, the groove engaging member 31 and the drive part 32 are provided.

  The groove engaging member 31 is a member that engages with the groove 23 when the cam is switched. The specific configuration of the groove engaging member 31 is not particularly limited as long as it can engage with the groove 23. In this embodiment, a rod-shaped pin is used as an example of the groove engaging member 31.

  The drive unit 32 is a device that drives the groove engaging member 31. The drive unit 32 is supported by a predetermined portion of the internal combustion engine so that it does not move in the axial direction of the camshaft 10 when the groove engaging member 31 is engaged with the groove 23. The predetermined part of the internal combustion engine that supports the drive unit 32 is not particularly limited, and a cylinder head, a cylinder head cover, or the like can be used. It is assumed that the drive unit 32 according to the present embodiment is supported by the internal combustion engine so as to be fixed to the cylinder head of the internal combustion engine.

  The driving unit 32 drives the groove engaging member 31 so that the groove engaging member 31 protrudes and protrudes from the driving unit 32. The specific configuration of the drive unit 32 is not particularly limited, but in this embodiment, a solenoid actuator is used as an example. The solenoid actuator operates in response to an instruction from a control device (not shown), and causes the groove engaging member 31 to move in and out of the drive unit 32.

  As a control device for controlling the drive unit 32, an electronic control unit (Electronic Control Unit) including a CPU, a ROM, a RAM, and the like can be used. This control device acquires the position of the groove 23 based on the detection results of the cam position sensor that detects the position of the cam shaft 10 and the crank position sensor that detects the position of the crankshaft of the internal combustion engine. The drive unit 32 is controlled so that the combined member 31 engages with the groove 23. The groove engaging device 30 includes this control device as one of the constituent elements.

  FIG. 1B is a schematic cross-sectional view showing the inside of the cam piece 20. Specifically, FIG. 1B schematically shows a cross-sectional view of the vicinity of a portion of the groove forming portion 24 facing the camshaft 10. The variable valve operating device 5 includes a pressure applying member 40. The pressure applying member 40 includes a contact member 41 and an urging member 42. The contact member 41 is a member that contacts the surface of the cam piece 20 that faces the cam shaft 10. In this embodiment, a sphere is used as an example of the contact member 41.

  The urging member 42 is a member that urges the contact member 41 in a direction perpendicular to the axial direction of the cam shaft 10 (upward in FIG. 1B). The cam shaft 10 according to the present embodiment is formed with a hole 13 whose depth direction is a direction perpendicular to the axial direction of the cam shaft 10, and the urging member 42 is disposed in the hole 13. The diameter of the hole 13 is set larger than the diameter of the contact member 41. In this embodiment, a spring is used as an example of the urging member 42.

  A first recess 50 and a second recess 51 are provided on the surface of the cam piece 20 facing the cam shaft 10. FIG. 1C is a schematic cross-sectional view for explaining the first recess 50 and the second recess 51 of the cam piece 20. A first inclined surface 52 that is inclined with respect to the axial direction of the cam shaft 10 and a second inclined surface 53 that is connected to the first inclined surface 52 are formed in the first concave portion 50 and the second concave portion 51. . The inclination angle of the first inclined surface 52 is set smaller than the inclination angle of the second inclined surface 53. In addition, the 1st recessed part 50 and the 2nd recessed part 51 which concern on a present Example are formed in the part of the groove formation part 24 of the cam piece 20. As shown in FIG. However, the portion where the first recess 50 and the second recess 51 are formed is not limited to this, and for example, the first recess 50 and the second recess 51 may be formed in the cam portion of the cam piece 20. Alternatively, it may be formed across the groove forming portion 24 and the cam portion.

  The abutting member 41 urged by the urging member 42 abuts on the first inclined surface 52 after the switching of the cam that drives the engine valve 100 is completed. Accordingly, the pressure applying member 40 can apply pressure to the first inclined surface 52 after the cam switching is completed. The abutting member 41 urged by the urging member 42 abuts on the second inclined surface 53 when the cam is switched. Thereby, the pressure applying member 40 can apply pressure to the second inclined surface 53 when the cam is switched. That is, the pressure applying member 40 according to the present embodiment is a member that applies pressure to the first inclined surface 52 after the cam switching is completed and applies pressure to the second inclined surface 53 when the cam is switched. If it is such a member, the specific configuration of the pressure applying member 40 is not limited to the configuration including the contact member 41 and the urging member 42 as in the present embodiment. Further, the specific configuration of the contact member 41 is not limited to a sphere, and the specific configuration of the biasing member 42 is not limited to a spring.

  FIG. 3A is a schematic diagram for explaining the details of the groove 23. Specifically, FIG. 3A schematically illustrates a state in which the groove 23 is developed in the circumferential direction of the groove forming portion 24. In FIG. 3A, the rotation direction of the groove forming portion 24 (this is also the rotation direction of the cam shaft 10) is the upward direction. The groove 23 has a first vertical portion 25, a second vertical portion 27, and a third vertical portion 29 having a groove direction perpendicular to the axial direction of the cam shaft 10. The groove 23 includes a first inclined portion 26 and a second inclined portion 28 having a groove direction inclined with respect to the axial direction of the cam shaft 10. The first vertical portion 25, the first inclined portion 26, the second vertical portion 27, the second inclined portion 28, and the third vertical portion 29 are connected in this order.

  When the cam that drives the engine valve 100 is switched from the first cam 21 to the second cam 22, the groove engaging member 31 sequentially engages the first vertical portion 25, the first inclined portion 26, and the second vertical portion 27. . When the cam that drives the engine valve 100 is switched from the second cam 22 to the first cam 21, the groove engaging member 31 sequentially engages the second vertical portion 27, the second inclined portion 28, and the third vertical portion 29. .

  FIG. 3B to FIG. 3D are schematic views for explaining an engagement mode of the groove engaging member 31 to the groove 23. The state where the groove engaging member 31 is engaged with the groove 23 is schematically illustrated in the upper stage of FIGS. 3B to 3D, and the cam for driving the engine valve 100 is switched in the lower stage. The situation is schematically illustrated. In the upper drawing, the rotation direction of the groove forming portion 24 of the cam piece 20 is the upward direction.

  As shown in FIG. 3B, when the cam that drives the engine valve 100 is switched from the first cam 21 to the second cam 22, the drive unit 32 that receives an instruction from the control device drives the groove engaging member 31. By projecting from the part 32, the groove engaging member 31 is engaged with any part of the first vertical part 25. The groove engaging member 31 engaged with the first vertical portion 25 moves relative to the groove 23 as the cam shaft 10 rotates. As shown in FIG. 3C, when the groove engaging member 31 is engaged with the first inclined portion 26, the cam piece 20 is in the axial direction of the cam shaft 10 that the first inclined portion 26 receives from the groove engaging member 31. It moves to Fr side by force. The cam piece 20 moves in the axial direction of the cam shaft 10 as shown in FIG. 3 (d), when the groove engaging member 31 finishes engaging with the first inclined portion 26 and engages with the second vertical portion 27. Continue until the match starts. When the groove engaging member 31 is engaged with the second vertical portion 27, the driving unit 32 that has received an instruction from the control device causes the groove engaging member 31 to be immersed in the driving unit, thereby the groove 23 of the groove engaging member 31. End the engagement. As described above, the cam that drives the engine valve 100 is switched from the first cam 21 to the second cam 22.

  On the other hand, when the cam for driving the engine valve 100 is switched from the second cam 22 to the first cam 21 (not shown), the drive unit 32 that receives an instruction from the control device causes the groove engaging member 31 to be driven to the drive unit 32. The groove engaging member 31 is engaged with any part of the second vertical portion 27 by protruding from the second vertical portion 27. The groove engaging member 31 engaged with the second vertical portion 27 moves relative to the groove 23 as the cam shaft 10 rotates. When the groove engaging member 31 engages with the second inclined portion 28, the cam piece 20 moves to the Rr side by the axial force of the cam shaft 10 received by the second inclined portion 28 from the groove engaging member 31. The movement of the cam piece 20 in the axial direction of the cam shaft 10 is continued until the groove engaging member 31 finishes engaging the second inclined portion 28 and starts engaging the third vertical portion 29. When the groove engaging member 31 is engaged with the third vertical portion 29, the driving unit 32 that has received an instruction from the control device causes the groove engaging member 31 to be immersed in the driving unit, thereby the groove 23 of the groove engaging member 31. End the engagement. As described above, the cam that drives the engine valve 100 is switched from the second cam 22 to the first cam 21.

  As described above, in the groove 23 of the groove forming portion 24, the cam that drives the engine valve 100 is switched between the first cam 21 and the second cam 22 when the groove engaging member 31 is engaged with the groove 23. It has such a structure. As long as it has such a structure, the specific structure of the groove 23 is not limited to the structure shown in FIG.

  FIGS. 4A to 4C are schematic diagrams for explaining the engagement relationship between the first inclined surface 52 and the second inclined surface 53 and the pressure applying member 40 at the time of switching the cam and after the end of the switching. It is sectional drawing. Specifically, FIG. 4A schematically shows a cross-sectional view of the state in which the contact member 41 is in contact with the first inclined surface 52 of the first recess 50 after the cam switching is completed. In FIG. 4A, the cam that drives the engine valve 100 is the first cam 21. FIG. 4B schematically shows a cross-sectional view of a state in which the cam that drives the engine valve 100 is being switched from the first cam 21 to the second cam 22 (that is, during cam switching). FIG. 4C is a cross-sectional view schematically showing a state where the contact member 41 is in contact with the first inclined surface 52 of the second recess 51 after the cam switching is completed. In FIG. 4C, the cam that drives the engine valve 100 is the second cam 22.

  As shown in FIG. 4A, the contact member 41 urged by the urging member 42 after the switching of the cam that drives the engine valve 100 from the second cam 22 to the first cam 21 is completed. The pressure applying member 40 applies pressure to the first inclined surface 52 of the first recess 50 by contacting the first inclined surface 52 of the first recess 50.

  When the cam that drives the engine valve 100 is switched from the first cam 21 to the second cam 22, the cam piece 20 moves to the Fr side with respect to the cam shaft 10 from the position of FIG. As a result, the contact member 41 contacts the second inclined surface 53 of the first recess 50. Next, when the cam piece 20 moves to the Fr side, the contact member 41 moves into the hole 13. In FIG. 4B, the contact member 41 is pushed into the hole 13 by the protruding portion (hereinafter sometimes referred to as a protruding portion) between the first recess 50 and the second recess 51. It is shown in the figure. When the cam piece 20 moves further to the Fr side with respect to the cam shaft 10 from the position shown in FIG. 4B, the contact member 41 comes into contact with the second inclined surface 53 of the second recess 51, and thereafter, FIG. ) Abuts on the first inclined surface 52 of the second recess 51. When the contact member 41 contacts the first inclined surface 52 of the second recess 51, the switching of the cam that drives the engine valve 100 from the first cam 21 to the second cam 22 ends.

  When the cam for driving the engine valve 100 is switched from the second cam 22 to the first cam 21, the contact member 41 has a stroke reverse to that described in FIGS. 4 (a) to 4 (c). Will be followed. That is, when the cam that drives the engine valve 100 is switched from the second cam 22 to the first cam 21, the cam piece 20 moves to the Rr side with respect to the cam shaft 10. In this case, as shown in FIG. 4C, the contact member 41 changes from a state in which the contact member 41 contacts the first inclined surface 52 of the second recess 51 to a state in which the contact member 41 contacts the second inclined surface 53 of the second recess 51. After that, the first concave portion 50 is in contact with the projecting portion between the first concave portion 50 and the second concave portion 51 and the second inclined surface 53 of the first concave portion 50 in order, as shown in FIG. The first inclined surface 52.

  FIG. 5A to FIG. 5C are schematic cross-sectional views for explaining the details of the first inclined surface 52 and the second inclined surface 53. Specifically, FIG. 5A schematically illustrates a cross-sectional view of the contact member 41 in contact with the first inclined surface 52 of the first recess 50, and FIG. FIG. 5C is a schematic cross-sectional view showing a state where the first concave portion 50 is in contact with the second inclined surface 53, and FIG. 5C schematically shows a state where the contact member 41 is in contact with the first inclined surface 52 of the second concave portion 51. FIG. In FIGS. 5A to 5C, cross-sectional hatching is omitted. Further, the contact member 41 is illustrated by an imaginary line.

  The first inclined surface 52 of the first concave portion 50 and the second concave portion 51 has the direction of the component force obtained by resolving the pressure received from the pressure applying member 40 in the axial direction of the cam shaft 10 after the cam switching is completed. It is inclined with respect to the axial direction of the camshaft 10 so as to be in a direction to be pressed against a predetermined portion (cam cap in this embodiment).

The inclination angle of the first inclined surface 52 will be specifically described. As shown in FIG. 5A, the first inclined surface 52 of the first recess 50 is formed on the contact member 41 after the switching of the cam that drives the engine valve 100 from the second cam 22 to the first cam 21 is completed. subjected to the pressure _{a 1} from. A vertical component force obtained by resolving the pressure A ₁ in the direction perpendicular to the axial direction of the cam shaft 10 is illustrated by a _y , and a horizontal component force obtained by decomposing the pressure A ₁ in the axial direction of the cam shaft 10 is illustrated by a _{x 1} . ing. The first inclined surface 52 of the first recess 50 is inclined so that the direction of the horizontal component force a _{x1 is} the direction in which the cam piece 20 is pressed against the second cam cap 131. As a result, the cam piece 20 can be pressed against the second cam cap 131 by the horizontal component force a _x1 after the switching of the cam for driving the engine valve 100 from the second cam 22 to the first cam 21 is completed (FIG. 2).

On the other hand, as shown in FIG. 5C, after the switching of the cam for driving the engine valve 100 from the first cam 21 to the second cam 22, the first inclined surface 52 of the second recess 51 is in contact with the first cam 21. A pressure A ₁ is received from the member 41. A vertical component force obtained by resolving the pressure A ₁ in the direction perpendicular to the axial direction of the cam shaft 10 is illustrated by a _y , and a horizontal component force obtained by decomposing the pressure A ₁ in the axial direction of the cam shaft 10 is illustrated by a _{x 1} . ing. The first inclined surface 52 of the second recess 51 is inclined so that the direction of the horizontal component force a _{x1 in} FIG. 5C is the direction in which the cam piece 20 is pressed against the first cam cap 130. As a result, after the switching of the cam for driving the engine valve 100 from the first cam 21 to the second cam 22 is completed, the cam piece 20 can be pressed against the first cam cap 130 by the horizontal component force a _x1 (FIG. 1 (a)).

In the present embodiment, the first concave portion 50 and the second concave portion 51 are formed symmetrically with respect to the apex of the protruding portion between the first concave portion 50 and the second concave portion 51. Therefore, the magnitude of the inclination angle of the first inclined surface 52 of the first recess 50 is the same as the inclination angle of the first inclined surface 52 of the second recess 51. As a result, the horizontal component force a _x1 in FIG. 5C is the same in magnitude and opposite in direction to the horizontal component force a _{x1 in} FIG.

As shown in FIG. 5B, the second inclined surface 53 of the first recess 50 is moved from the contact member 41 when the cam for driving the engine valve 100 is switched from the first cam 21 to the second cam 22. subjected to the pressure _{a 2.} The vertical component force decomposed in a direction perpendicular to the axial direction of the pressure A ₂ a cam shaft 10 is shown by a _y, a horizontal component force obtained by dividing the pressure A ₂ in the axial direction of the cam shaft 10 is shown by a _x2 ing.

Here, as described above, the inclination angle of the first inclined surface 52 is set smaller than the inclination angle of the second inclined surface 53. Therefore, the horizontal component force a _x1 in FIG. 5A is smaller than the horizontal component force a _{x2 in} FIG. As described above, since the inclination angle of the first inclined surface 52 is smaller than the inclination angle of the second inclined surface 53, the component force in the axial direction of the cam shaft 10 applied from the pressure applying member 40 to the cam piece 20 after the cam switching is completed. The magnitude of (horizontal component force a _x1 ) may be made smaller than the magnitude of the component force in the axial direction of the cam shaft 10 (horizontal component force a _x2 ) applied from the pressure applying member 40 to the cam piece 20 when the cam is switched. it can.

The contact member 41 contacts the second inclined surface 53 of the second recess 51 when the cam that drives the engine valve 100 is switched from the first cam 21 to the second cam 22. Here, since the magnitude of the inclination angle of the second inclined surface 53 of the second recessed portion 51 according to the present embodiment is the same as the angle of inclination of the second inclined surface 53 of the first recessed portion 50, the second recessed portion pressure second inclined surface 53 of the 51 receives from the contact member 41, a ₂ and the size of the FIG. 5 (b) is a force in the direction the same opposition. As a result, the horizontal component force a _x2 of the pressure received by the second inclined surface 53 of the second recess 51 from the abutting member 41 is the same magnitude as the horizontal component force a _x2 of FIG. .

Since the inclination angle of the first inclined surface 52 of the second recessed portion 51 is also smaller than the inclination angle of the second inclined surface 53 of the second recessed portion 51, the first inclined surface 52 of the second recessed portion 51 receives from the contact member 41. The magnitude of the component force a _x1 is smaller than the magnitude of the horizontal component force a _x2 received by the second inclined surface 53 of the second recess 51 from the contact member 41.

  In the present embodiment, the first concave portion 50 and the second concave portion 51 are formed symmetrically with respect to the apex of the projecting portion between the first concave portion 50 and the second concave portion 51, but are not limited thereto. It is not something. The 1st recessed part 50 and the 2nd recessed part 51 may not be such a left-right symmetric shape. Further, the magnitude of the inclination angle of the first inclined surface 52 of the first recess 50 and the magnitude of the inclination angle of the first inclined surface 52 of the second recess 51 may be different values, and the second of the first recess 50 may be different. The value of the inclination angle of the inclined surface 53 may be different from the value of the inclination angle of the second inclined surface 53 of the second recess 51.

Then, the effect of the variable valve apparatus 5 is demonstrated. According to the variable valve device 5, as described in FIG. 5, it can be pressed after completion switching cams by the horizontal component force a _x1, a cam piece 20 at a predetermined position of the internal combustion engine. Specifically, the cam piece 20 can be pressed against the cam cap after the cam switching is completed. More specifically, as shown in FIG. 1 (a), after the switching of the cam for driving the engine valve 100 from the first cam 21 to the second cam 22, the first cam 21 on the Fr side of the cam piece 20 is moved. It can be pressed against the first cam cap 130. As shown in FIG. 2, the second cam 22 on the Rr side of the cam piece 20 is pressed against the second cam cap 131 after the switching of the cam that drives the engine valve 100 from the second cam 22 to the first cam 21 is completed. Can do. Thereby, the position of the axial direction with respect to the cam shaft of the cam piece 20 can be held after the cam switching is completed.

In addition, since the inclination angle of the first inclined surface 52 is smaller than the inclination angle of the second inclined surface 53, the pressure applied from the pressure applying member 40 to the first inclined surface 52 after the switching of the cam is decomposed in the axial direction. The magnitude of the horizontal component force a _x1 can be made smaller than the magnitude of the horizontal component force a _x2 obtained by resolving the pressure applied from the pressure applying member 40 to the second inclined surface 53 in the axial direction when the cam is switched. . Thereby, compared with the case where the inclination angle of the 1st inclined surface 52 is the same as the inclination angle of the 2nd inclined surface 53, the force which presses the cam piece 20 to the predetermined site | part of an internal combustion engine after completion | finish of a cam switching can be made small. . As a result, it is possible to suppress wear of the cam piece 20 or wear of a predetermined portion of the internal combustion engine to which the cam piece 20 is pressed. Specifically, in this embodiment, the wear of the cam piece 20 or the wear of the cam cap can be suppressed. More specifically, wear of the first cam 21 or the first cam cap 130 on the Fr side can be suppressed, and wear of the second cam 22 or the second cam cap 131 on the Rr side can be suppressed.

Further, since the inclination angle of the second inclined surface 53 is larger than the inclination angle of the first inclined surface 52, the movement of the cam piece 20 in the axial direction at the time of switching of the cam can be promoted. Specifically, when the cam for driving the engine valve 100 is switched from the first cam 21 to the second cam 22, when the contact member 41 contacts the second inclined surface 53 of the second recess 51, the cam piece 20 A horizontal component force a _x2 in the Fr direction is received from the second inclined surface 53 of the second recess 51. Thereby, the movement to the Fr side of the cam piece 20 can be promoted. Further, when the cam for driving the engine valve 100 is switched from the second cam 22 to the first cam 21, when the abutment member 41 abuts on the second inclined surface 53 of the first recess 50, the cam piece 20 is in the first recess. The horizontal component force a _x2 in the Rr direction is received from the 50 second inclined surfaces 53. Thereby, the movement of the cam piece 20 to the Rr side can be promoted.

  Further, according to the variable valve operating apparatus 5, the cam piece 20 includes the groove 23 (the first inclined portion 26 and the second inclined portion 28) having a groove direction inclined with respect to the axial direction of the cam shaft 10. Since the device 5 includes the groove engaging member 31 that engages with the groove 23 when the cam is switched, the cam piece 20 is cammed by engaging the groove engaging member 31 with the groove 23 when the cam is switched. It can be moved in the axial direction of the shaft. The mechanism for moving the cam piece 20 in the axial direction of the camshaft 10 at the time of cam switching is limited to a mechanism including the groove 23 and the groove engaging member 31 that engages with the groove 23 as in the present embodiment. It is not something. For example, the cam piece 20 does not include the groove 23, and the variable valve apparatus 5 may include an actuator that moves the cam piece 20 in the axial direction of the cam shaft 10 instead of the groove engaging member 31. Even if the variable valve operating apparatus 5 has such a structure, the cam piece 20 can be moved in the axial direction with respect to the cam shaft 10 when the cam is switched.

  Further, according to the variable valve operating device 5, the first inclined surface 52 and the second inclined surface 53 are formed in the recesses (the first recess 50 and the second recess 51) provided on the surface of the cam piece 20 facing the cam shaft 10. The formed pressure application member 40 is disposed in the contact member 41 that contacts the first inclined surface 52 and the second inclined surface 53 and the hole 13 provided in the cam shaft 10 so that the contact member 41 is moved in the axial direction. Since the biasing member 42 biasing in the vertical direction is provided, the pressure applying member 40 can be accommodated inside the cam piece 20 and the cam shaft 10. Thereby, the variable valve gear 5 can be made compact.

  Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to such specific embodiments, and various modifications and changes can be made within the scope of the gist of the present invention described in the claims. It can be changed.

DESCRIPTION OF SYMBOLS 5 Variable valve apparatus 10 Cam shaft 13 Hole 20 Cam piece 21 1st cam 22 2nd cam 23 Groove 24 Groove formation part 30 Groove engagement apparatus 31 Groove engagement member 32 Drive part 40 Pressure application member 41 Contact member 42 Energizing Member 50 1st recessed part 51 2nd recessed part 52 1st inclined surface 53 2nd inclined surface

Claims (4)

A plurality of cams as cams for driving an engine valve of the internal combustion engine; and when the cams for driving the engine valve are switched, the cams move in the axial direction of the cam shaft with respect to the cam shaft; A cam piece having an inclined first inclined surface and a second inclined surface connected to the first inclined surface;
A pressure applying member that applies pressure to the first inclined surface after switching of the cam that drives the engine valve and applies pressure to the second inclined surface at the time of switching of the cam;
The first inclined surface has a direction of a component force obtained by resolving the pressure received from the pressure applying member in the axial direction after completion of the cam switching so as to press the cam piece against a predetermined part of the internal combustion engine. Inclined with respect to the axial direction,
The variable valve operating apparatus, wherein an inclination angle of the first inclined surface is smaller than an inclination angle of the second inclined surface. The cam piece includes a groove having a groove direction inclined with respect to the axial direction,
The variable valve operating apparatus according to claim 1, further comprising a groove engaging member that engages with the groove when the cam is switched. The first inclined surface and the second inclined surface are formed in a recess provided on a surface of the cam piece facing the cam shaft,
The pressure applying member is disposed in a contact member that contacts the first inclined surface and the second inclined surface, and a hole provided in the cam shaft, and the contact member is disposed in the axial direction of the cam shaft. The variable valve operating apparatus according to claim 1, further comprising: a biasing member that biases in a vertical direction.   The variable valve operating apparatus according to any one of claims 1 to 3, wherein the predetermined portion of the internal combustion engine is a cam cap.

Images