JP2015090079A - Variable valve gear of engine for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify a structure of a variable valve gear and a method for operating the same when changing operation characteristics of a valve by moving a cam carrier having a plurality of cams in an axial direction of a cam shaft.SOLUTION: For example, a first intake cam 11a and a second intake cam 11b having different valve operation characteristics and adjacent with each other in the axial direction are arranged on an outer periphery of an intake cam carrier 13 integrally rotated with an intake cam shaft 6 and movable along the axial direction of the intake cam shaft 6. A pair of intake end cam surfaces 22 having a height difference in the axial direction is arranged on each of axial direction both ends of the intake cam carrier 13. An intake cam control shaft 24 rotatable around an axis parallel to the intake cam shaft 6 is disposed on a radial direction side part of the intake cam shaft 6. A pair of intake cam pins 28 having an outer peripheral surface selectively brought into contact with one of the pair of the intake end cam surfaces 22 so as to move the intake cam carrier 13 to the axial direction is attached to the intake cam control shaft 24 in a state of having a phase difference in the rotating direction of the intake cam control shaft 24.

Description

  The present invention relates to a variable valve operating apparatus for a vehicle engine, and is particularly suitable for a variable valve operating apparatus for a vehicle engine that achieves different valve operating characteristics by switching a plurality of cams.

  An example of such a variable valve operating device for a vehicle engine is disclosed in Patent Document 1 below. In this variable valve operating system for a vehicle engine, a plurality of cams having different valve operating characteristics are formed on the outer periphery of a cam carrier that rotates integrally with the cam shaft, and the valve is moved by moving the cam carrier in the axial direction of the cam shaft. The cam to be operated is switched. In order to move the cam carrier in the axial direction, a spiral guide groove is formed on the outer periphery of the cam carrier, and the cam carrier is reciprocated in the radial direction so as to face the radial side of the guide groove. Place a pair of possible pins on the cylinder head. Then, the cam carrier is moved in the axial direction by inserting / removing the pins into / from the guide groove by the actuator.

Japanese Patent No. 3980699

  However, in the variable valve operating apparatus for a vehicle engine described in Patent Document 1, an actuator is required for each pin. Therefore, there is a problem that the structure is complicated and the cost is increased. Further, since the two pins are operated alternately, there is a problem that the operation method of the pins is complicated.

  The present invention has been made paying attention to the above-described problems, and has a structure when a cam carrier in which a plurality of cams are formed is moved in the axial direction of the cam shaft to change the operating characteristics of the valve. It is another object of the present invention to provide a variable valve operating apparatus for a vehicle engine capable of simplifying the operation method.

  A first aspect of the present invention is a variable valve operating apparatus for a vehicle engine that achieves different valve operating characteristics by switching a plurality of cams, and is formed in a cylindrical shape surrounding a cam shaft, and is integrated with the cam shaft. A cam carrier that rotates and is movable in the axial direction of the cam shaft, and a plurality of cams that have different valve operating characteristics and are arranged on the outer periphery of the cam carrier so as to be adjacent to each other in the axial direction of the cam carrier; The cam carrier is disposed at each of both axial ends of the cam carrier and forms a pair, and has an end cam surface having a height difference in the axial direction of the cam carrier, and is disposed on a side of the cam shaft in the radial direction. A control shaft rotatable around an axis parallel to the shaft, and attached to the control shaft with a phase difference in the rotation direction of the control shaft, and an outer peripheral surface is selected from one of the pair of end cam surfaces Touched Characterized by comprising a pair of pins for moving the cam carrier in an axial direction Te.

  According to a second aspect of the present invention, the pin is formed of a head portion that contacts the end cam surface, and a material that is elastically deformable in a radial direction of the cam carrier, and connects the head portion to the control shaft. It is preferable to be provided with the connection part to perform.

  Thus, according to the first aspect, when a plurality of cams are switched to achieve different valve operating characteristics, the cam carrier that rotates integrally with the cam shaft and is movable in the axial direction of the cam shaft, It is formed in a cylindrical shape surrounding the cam shaft. A plurality of cams are arranged on the outer periphery of the cam carrier so as to have different valve operating characteristics and to be adjacent to each other in the axial direction of the cam carrier. In addition, a pair of end cam surfaces having a height difference in the axial direction of the cam carrier are arranged at both ends in the axial direction of the cam carrier. Further, a control shaft that is rotatable around an axis parallel to the cam shaft is disposed on the side of the cam shaft in the radial direction. Then, a pair of pins whose outer peripheral surfaces are selectively brought into contact with either one of the pair of end cam surfaces and move the cam carrier in the axial direction are used as control shafts with a phase difference in the rotation direction of the control shaft. Install. Therefore, by rotating the control shaft, either one of the pair of pins can be selectively brought into contact with the end cam surface, and the cam carrier can be moved in the axial direction. Therefore, the structure of the actuator for moving the pair of pins to the contact position with the end cam surface can be simplified, and in addition, the operation method of the pins can be simplified.

  Further, according to the second aspect, the pin is configured with a head portion that contacts the end cam surface and a material that is elastically deformable in the radial direction of the cam carrier, and the head portion is connected to the control shaft. And a connecting portion. The end cam surface has a base surface orthogonal to the axis of the cam carrier. If this base surface is a surface that is low in the axial direction of the cam carrier, the end cam surface also has a cam crest that is higher in the axial direction of the cam carrier than the base surface, that is, protrudes outward in the axial direction. The pin should be moved to a position facing the base surface in a section corresponding to the base surface in the rotation direction of the cam carrier. However, when a cam carrier for a plurality of cylinders is moved in the axial direction by one control shaft in a multi-cylinder engine, the pin may come into contact with the outer peripheral surface of the cam crest portion of the end cam surface. That is, the pin movement timing deviates from the optimum switching timing. In such a case, by connecting the head portion that contacts the end cam surface and the control shaft with a connecting portion that can be elastically deformed only in the radial direction of the cam carrier, the connecting portion bends in the radial direction of the cam carrier, Deviations in pin movement timing can be allowed.

FIG. 1 is a perspective view of the inside of a cylinder head showing a first embodiment of a variable valve operating apparatus for a vehicle engine according to the present invention. FIG. 2 is a perspective view of one cylinder inside the cylinder head of FIG. FIG. 3 is a longitudinal sectional view of the cylinder head of FIG. FIG. 4 is a development view of the valve mechanism in the cylinder head of FIG. FIG. 5 is a perspective view of a control shaft and pins constituting the variable valve operating apparatus of FIG. FIG. 6 is a perspective view showing details of the variable valve operating apparatus of FIG. FIG. 7 is an explanatory diagram of the operation of the variable valve operating apparatus of FIG. FIG. 8 is an explanatory view of the operation of the variable valve operating apparatus of FIG. FIG. 9 is an explanatory view of the operation of the variable valve operating apparatus of FIG. FIG. 10 is an explanatory diagram of the operation of the variable valve operating apparatus of FIG. FIG. 11 is a longitudinal sectional view of a cylinder head showing a second embodiment of the variable valve operating apparatus for a vehicle engine of the present invention. FIG. 12 is a perspective view of a control shaft and pins constituting the variable valve operating apparatus of FIG. FIG. 13 is an explanatory view of the operation of the variable valve operating apparatus of FIG. FIG. 14 is an explanatory diagram of the operation of the variable valve operating apparatus of FIG.

  Next, a first embodiment of a variable valve operating apparatus for a vehicle engine according to the present invention will be described with reference to the drawings. 1 is a perspective view of the inside of the cylinder head of the present embodiment, FIG. 2 is a perspective view of one cylinder inside the cylinder head of FIG. 1, FIG. 3 is a longitudinal sectional view of the cylinder head of FIG. FIG. 2 is a development view of a valve mechanism inside the cylinder head of FIG. 1. In the following description, the direction in which the cylinder head cover is attached to the cylinder head body is defined as the engine upper direction, and the reverse direction as the engine lower direction. The variable valve operating apparatus 1 of this embodiment is built in the cylinder head 3 of the engine 2. The overall configuration of the cylinder head 3 is substantially the same as that of a cylinder head of a normal in-line four-cylinder engine. For example, as shown in FIG. , A cam housing 8 attached to the upper portion thereof, and a cylinder head cover 5 covering the upper surface thereof. 1 and 2 show a state where the cylinder head cover 5 is removed. FIG. 4 shows an intake camshaft and an intake valve as a representative valve operating mechanism.

  The cam housing 8 houses the intake cam shaft 6 and the exhaust cam shaft 7 so as to be rotatable. In this cam housing 8, a ladder frame-like lower cam housing 9 in which the cylinder portion is hollowed is arranged on the upper end surface of the engine of the cylinder head body 4, and a similar ladder frame-like upper cam housing 10 is arranged thereabove. These are fixed to the cylinder head body 4. An intake cam shaft 6 and an exhaust cam shaft 7 are rotatably supported between the lower cam housing 9 and the upper cam housing 10 with their axes parallel to the cylinder row direction. The intake camshaft 6 and the exhaust camshaft 7 are respectively connected to the crankshaft by a timing chain (not shown), and are synchronously rotated at a speed half that of the crankshaft. An outer wall portion constituting the outer wall of the cylinder head 3 is formed around the lower cam housing 9, and the cylinder head cover 5 is attached to the upper end surface of the outer wall portion.

  In this embodiment, as clearly shown in FIG. 4, for example, the intake cam shaft 6 and the exhaust cam shaft 7, the intake cam 11 (11a and 11b in the figure), and the exhaust cam 12 are separated. Specifically, the intake cam shaft 6 and the exhaust cam shaft 7 are relatively straight cylindrical shafts in which no cam is formed. A cylindrical intake cam carrier 13 and exhaust cam carrier 14 are arranged for each cylinder so as to surround the outer periphery of the intake cam shaft 6 and the exhaust cam shaft 7. An intake cam 11 and an exhaust cam 12 are formed on each of the intake cam carrier 13 and the exhaust cam carrier 14. The intake cam carrier 13 and the exhaust cam carrier 14 are splined to the intake cam shaft 6 and the exhaust cam shaft 7, respectively. Therefore, the intake cam carrier 13 and the exhaust cam carrier 14 rotate integrally with the intake cam shaft 6 and the exhaust cam shaft 7 and are movable in the axial directions of the intake cam shaft 6 and the exhaust cam shaft 7.

  As representatively shown in the intake camshaft 6 and the intake cam carrier 13 in FIG. 4, the tooth spline formed on the inner peripheral surface of the intake cam carrier 13 is partially formed with a tooth missing portion. Yes. Similarly, the outer tooth spline of the intake camshaft 6 has a land portion 31 having a large diameter and no teeth at the position corresponding to the tooth missing portion of the inner tooth spline of the intake cam carrier 13 in the axial direction. They are formed in parallel. In the land portion 31, two hemispherical holes 32 are formed at the same pitch as the axial pitch of a first intake cam 11a and a second intake cam 11b described later. On the other hand, a through hole 33 is formed in the intake cam carrier 13 from the outer peripheral surface of the intake cam carrier 13 corresponding to the tooth missing portion toward the tooth missing portion. The through hole 33 accommodates a ball 34 that can be accommodated in the above-described hemispherical hole 32 and a spring 35 that presses the ball 34 against the hemispherical hole 32 or the land portion 31. A plug (blind plug) is provided outside the through hole 33. 36 is embedded and closed. This configuration is the same for the exhaust camshaft 7 and the exhaust cam carrier 14, and, as will be described later, the intake cam carrier 13 (exhaust cam carrier 14) is moved in the axial direction so that the first intake cam 11a and the second intake cam are moved. When any one of 11b (first exhaust cam 12a and second exhaust cam 12b) is selectively brought into contact with the intake rocker arm 15 (exhaust rocker arm 16), the ball 34 is stored in one hemispherical hole 32, The selected state of the cam can be maintained.

  An intake rocker arm 15 and an exhaust rocker arm 16 are respectively arranged below the intake cam 11 and the exhaust cam 12, and the intake cam 11 and the exhaust cam 12 are respectively arranged on rollers at the center of the intake rocker arm 15 and the exhaust rocker arm 16. In contact. Among these, the intake valve 17 is in contact with the lower side of one end of the intake rocker arm 15 in the longitudinal direction, and the intake lash adjuster 18 is in contact with the lower side of the other end. The exhaust valve 19 is in contact with the exhaust rocker arm 16 below one end in the longitudinal direction, and the exhaust lash adjuster 20 is in contact with the other end. A valve spring 21 is interposed between the intake valve 17 and the exhaust valve 19 and the cylinder head body 4. Accordingly, when the cam crests of the intake cam 11 and the exhaust cam 12 push down the intake rocker arm 15 and the exhaust rocker arm 16, respectively, the intake valve 17 and the exhaust valve 19 are moved below the engine, that is, on the combustion chamber side (not shown). So-called valve is opened.

  In the present embodiment, on the outer periphery of the intake cam carrier 13, the first intake cam 11a and the second intake cam 11b are arranged in the axial direction of the intake cam carrier 13 as a plurality of intake cams 11 having different valve operating characteristics, that is, cam profiles. It is formed to be adjacent. Either the first intake cam 11a or the second intake cam 11b is selectively brought into contact with the intake rocker arm 15. Similarly, on the outer periphery of the exhaust cam carrier 14, the first exhaust cam 12a and the second exhaust cam 12b are adjacent to each other in the axial direction of the exhaust cam carrier 14 as a plurality of exhaust cams 12 having different valve operating characteristics, that is, cam profiles. It is formed as follows. Either the first exhaust cam 12a or the second exhaust cam 12b selectively contacts the exhaust rocker arm 16. In the present embodiment, for example, the lift amount of the intake valve 17 is relatively small in the second intake cam 11b with respect to the first intake cam 11a. Similarly, for example, the lift amount of the exhaust valve 19 is relatively small in the second exhaust cam 12b with respect to the first exhaust cam 12a. In addition to this, different valve operating characteristics of adjacent cams can be desired characteristics. For example, the lift amount of the intake valve 17 by the second intake cam 11b can be set to 0, and the lift amount of the exhaust valve 19 by the second exhaust cam 12b can be set to 0. In that case, when the second intake cam 11b and the second exhaust cam 12b are selectively in contact with the intake rocker arm 15 and the exhaust rocker arm 16, respectively, if the fuel injection to the corresponding cylinder is stopped, By simply reciprocating the piston in the cylinder bore, the cylinder is in a so-called deactivation state, and a selective cylinder deactivation engine can be obtained.

  In order to selectively contact either the first intake cam 11 a or the second intake cam 11 b with the intake rocker arm 15, it is necessary to move the intake cam carrier 13 in the axial direction of the intake cam carrier 13. Further, in order to selectively contact either the first exhaust cam 12 a or the second exhaust cam 12 b with the exhaust rocker arm 16, it is necessary to move the exhaust cam carrier 14 in the axial direction of the exhaust cam carrier 14. . Therefore, an intake end cam surface 22 and an exhaust end cam surface 23 are formed at both axial end portions (both end surfaces) of the intake cam carrier 13 and axial end portions (both end surfaces) of the exhaust cam carrier 14, respectively. . Therefore, for each intake cam carrier 13, the intake end cam surface 22 forms a pair at both ends in the axial direction of the intake cam carrier 13, and for each exhaust cam carrier 14, the exhaust end cam surface 23 is the axis of the exhaust cam carrier 14. A pair is formed at both ends in the direction. For example, as representatively shown in FIG. 4, the intake end cam surface 22 has an intake end cam base surface 22 a orthogonal to the axis of the intake cam carrier 13. If the intake end cam base surface 22a is a surface that is low in the axial direction of the intake cam carrier 13, the intake end cam surface 22 is higher in the axial direction of the intake cam carrier 13 than the intake end cam base surface 22a. An intake end cam crest 22b protruding outward in the axial direction is also formed. This configuration is the same for the exhaust end cam surface 23. The exhaust end cam surface 23 is formed with an exhaust end cam base surface 23a having a low axial height and an exhaust end cam crest 23b having a high axial height. Has been. The intake end cam surface 22 and the exhaust end cam surface 23 at both ends in the axial direction are formed symmetrically with respect to the axial center lines of the intake cam carrier 13 and the exhaust cam carrier 14, respectively. Accordingly, if a cam follower that does not move in the axial direction of the intake cam carrier 13, such as a pin, is brought into contact with either one of the intake end cam surfaces 22 at both axial ends, the cam profile of the intake end cam crest 22b. , The intake cam carrier 13 moves relatively in the axial direction. Similarly, if a cam follower that does not move in the axial direction of the exhaust cam carrier 14, for example, a pin, is brought into contact with either one of the exhaust end cam surfaces 23 at both ends in the axial direction, the cam of the exhaust end cam crest 23b The exhaust cam carrier 14 moves relatively in the axial direction along the profile.

  In this embodiment, a pin as a cam follower that does not move in the axial direction is attached to each of the intake cam control shaft 24 and the exhaust cam control shaft 25. The intake cam control shaft 24 is disposed on the side of the intake cam shaft 6 in the radial direction for each cylinder, that is, for each intake cam carrier 13, and is sandwiched between the lower cam housing 9 and the upper cam housing 10 constituting the cam housing 8. In this way, it is rotatably supported around an axis parallel to the axial direction of the intake camshaft 6. For example, as shown in FIG. 2, each intake cam control shaft 24 is sandwiched between a lower cam housing 9 and an upper cam housing 10 constituting the cam housing 8, and the intake cam control shaft 24 itself An intake cam actuator 26 such as an electric motor that rotates around the axis is coupled. Similarly, the exhaust cam control shaft 25 is disposed on the side of the exhaust cam shaft 7 in the radial direction for each cylinder, that is, for each exhaust cam carrier 14, and the lower cam housing 9 and the upper cam housing 10 constituting the cam housing 8 are arranged. It is supported so as to be rotatable around an axis parallel to the axial direction of the exhaust camshaft 7 so as to be sandwiched therebetween. For example, as shown in FIG. 2, each exhaust cam control shaft 25 is sandwiched between a lower cam housing 9 and an upper cam housing 10 constituting the cam housing 8, and the exhaust cam control shaft 25 itself. An exhaust cam actuator 27 such as an electric motor that rotates around the axis is connected.

  FIG. 5 shows a perspective view of the intake cam control shaft 24 as a representative. FIG. 6 shows details of the variable valve operating apparatus 1 operated by the intake cam control shaft 24 as a representative. The intake cam pins 28 are attached at the axial end portions of the intake cam control shafts 24 so as to protrude in the radial direction of the intake cam control shafts 24. That is, a pair of intake cam pins 28 is provided for each intake cam control shaft 24 or each intake cam carrier 13. Specifically, when one of the intake cam pins 28 is in contact with the top of the intake end cam crest 22b of the nearest intake end cam surface 22, the other intake cam pin 28 is on the opposite intake end. The cam surface 22 is disposed at a position that fits in the intake end cam base surface 22a. In the present embodiment, the two intake cam pins 28 forming a pair are attached to the intake cam control shaft 24 in a state where there is a phase difference in the rotation direction of the intake cam control shaft 24. In other words, the two intake cam pins 28 are attached to the intake cam control shaft 24 at different attachment angles. The phase difference between the two intake cam pins 28 is the same as the rotation angle of the intake cam actuator 26 described above, and is set in advance. This rotation angle is achieved, for example, by defining the number of steps of the step motor or by restricting the rotation of the rotation shaft of the intake cam actuator 26 with a notch or a pin. Similarly, with respect to the exhaust cam control shaft 25, two exhaust cam pins 29 are attached to both ends of each exhaust cam control shaft 25 in the axial direction, and are rotated by a rotation angle corresponding to a phase difference by the exhaust cam actuator 27. . Note that both the intake cam pin 28 and the exhaust cam pin 29 are solid solid cylindrical bodies.

  Hereinafter, as a representative of the intake cam carrier 13, the operation of the variable valve gear 1 of the present embodiment will be described. In FIG. 7, the intake cam carrier 13 is moved to the left end in the figure, and the second intake cam 11 b is in contact with the intake rocker arm 15. In this state, the right intake cam pin 28 on the right side of the drawing is in contact with the right intake end cam surface 22 on the right side of the drawing (the state shown in FIG. 10 described later). At this time, the ball 34 is pushed into the left hemispherical hole 32 shown in FIG. 4 (right side of the vehicle), and the intake cam carrier 13 does not easily move in the axial direction. In FIG. 7, the intake cam control shaft 24 is rotated from the opposite side to the front side of the drawing from this state, and the left intake cam pin 28 in the drawing is moved to the intake end cam base surface 22a of the left intake end cam surface 22 in the drawing. The state housed in is shown. From this state, when the intake camshaft 6 and the intake cam carrier 13 rotate from the other side of the drawing to the near side, the intake cam pin 28 on the left side of the drawing is the intake end cam peak portion of the intake end cam surface 22 on the left side of the drawing. Since the intake cam pin 28 does not move in the axial direction, the intake cam carrier 13 relatively moves to the right in the drawing, that is, in the axial direction of the intake cam carrier 13. Then, as shown in FIG. 8, when the left intake cam pin 28 in the drawing contacts the top of the intake end cam crest 22b of the left intake end cam surface 22 in the drawing, the intake cam carrier 13 is moved to the right end in the drawing. As a result, the first intake cam 11 a contacts the intake rocker arm 15. At this time, the ball 34 passes through the outer peripheral surface of the land portion 31, and the ball 34 is pushed into the right hemispherical hole 32 shown in FIG. 4 (left side of the vehicle). Therefore, even if the left intake cam pin 28 shown in FIG. 8 is separated from the intake end cam crest 22b of the left intake end cam surface 22 shown in FIG. 8, the intake cam carrier 13 does not easily move in the axial direction. . This effect is the same when the exhaust cam carrier 14 is moved in the axial direction and the exhaust cam 12 that contacts the exhaust rocker arm 16 is switched from the second exhaust cam 12b to the first exhaust cam 12a.

  On the other hand, in FIG. 9, the intake cam carrier 13 has moved to the right end in the figure, and the first intake cam 11 a is in contact with the intake rocker arm 15. In this state, the left intake cam pin 28 on the left side of the drawing is essentially in contact with the left intake end cam surface 22 on the opposite side of the drawing (state shown in FIG. 8). At this time, the ball 34 is pushed into the right hemispherical hole 32 shown in FIG. 4 (left side of the vehicle), and the intake cam carrier 13 does not easily move in the axial direction. In FIG. 9, the intake cam control shaft 24 is rotated from the near side of the drawing to the far side in this state, and the right intake cam pin 28 in the drawing is moved to the intake end cam base surface 22a of the right intake end cam surface 22 in the drawing. The state housed in is shown. From this state, when the intake camshaft 6 and the intake cam carrier 13 are rotated from the other side of the paper to the front side, the intake cam pin 28 on the right side of the drawing is the intake end cam peak portion of the intake end cam surface 22 on the right side of the drawing. Since the intake cam pin 28 does not move in the axial direction, the intake cam carrier 13 relatively moves to the left in the drawing, that is, in the axial direction of the intake cam carrier 13. As shown in FIG. 10, when the right intake cam pin 28 in the drawing contacts the top of the intake end cam crest 22b of the right intake end cam surface 22 in the drawing, the intake cam carrier 13 is moved to the left end in the drawing. As a result, the second intake cam 11 b comes into contact with the intake rocker arm 15. At this time, the ball 34 passes through the outer peripheral surface of the land portion 31 and is pushed into the left hemispherical hole 32 shown in FIG. 4 (right side of the vehicle). Therefore, even if the right intake cam pin 28 shown in FIG. 10 is separated from the intake end cam crest 22b of the right intake end cam surface 22 shown in FIG. 10, the intake cam carrier 13 does not easily move in the axial direction. . This operation is the same when the exhaust cam carrier 14 is moved in the axial direction and the exhaust cam 12 that contacts the exhaust rocker arm 16 is switched from the first exhaust cam 12a to the second exhaust cam 12b.

  As described above, in the variable valve operating apparatus for a vehicle engine according to the present embodiment, a plurality of cams such as a combination of the first intake cam 11a and the second intake cam 11b or a combination of the first exhaust cam 12a and the second exhaust cam 12b. Intake cam carriers that rotate integrally with the intake camshaft 6 and the exhaust camshaft 7 and are movable in the axial directions of the intake camshaft 6 and the exhaust camshaft 7 when achieving different valve operating characteristics by switching 13 and the exhaust cam carrier 14 are formed in a cylindrical shape surrounding the intake cam shaft 6 and the exhaust cam shaft 7, respectively. Further, the outer circumferences of the intake cam carrier 13 and the exhaust cam carrier 14 have a plurality of first and second valve valves having different valve operating characteristics and adjacent to each other in the axial direction of the intake cam carrier 13 and the exhaust cam carrier 14. A combination of the first intake cam 11a and the second intake cam 11b and a combination of the first exhaust cam 12a and the second exhaust cam 12b are arranged. Further, a pair of intake end cam surfaces having a difference in height in the axial direction of each of the intake cam carrier 13 and the exhaust cam carrier 14 are respectively provided at both axial ends of the intake cam carrier 13 and the exhaust cam carrier 14. 22 and the exhaust end cam surface 23 are arranged. Further, on the side in the radial direction of each of the intake camshaft 6 and the exhaust camshaft 7, an intake cam control shaft 24 and an exhaust cam control that can rotate about axes parallel to the intake camshaft 6 and the exhaust camshaft 7, respectively. Each of the shafts 25 is arranged. The outer peripheral surface is selectively brought into contact with either one of the pair of intake end cam surface 22 and exhaust end cam surface 23 to move each of the intake cam carrier 13 and the exhaust cam carrier 14 in the axial direction. The pair of intake cam pins 28 and exhaust cam pins 29 are respectively connected to the intake cam control shaft 24 and the exhaust cam control shaft 25 with a phase difference in the rotational direction of the intake cam control shaft 24 and the exhaust cam control shaft 25. Install. Therefore, by rotating each of the intake cam control shaft 24 and the exhaust cam control shaft 25, any one of the pair of intake cam pins 28 and exhaust cam pins 29 is selectively selected from the intake end cam surface 22 and the exhaust cam. The end cam surface 23 can be brought into contact with each other, and each of the intake cam carrier 13 and the exhaust cam carrier 14 can be moved in the axial direction. Accordingly, the structures of the intake cam actuator 26 and the exhaust cam actuator 27 that move the pair of intake cam pins 28 and exhaust cam pins 29 to the contact positions of the intake end cam surface 22 and the exhaust end cam surface 23, respectively. In addition, the operation method of each of the intake cam pin 28 and the exhaust cam pin 29 can be simplified.

  Next, a second embodiment of a variable valve operating apparatus for a vehicle engine according to the present invention will be described. FIG. 11 is a longitudinal sectional view of the cylinder head of the present embodiment. The cylinder head of FIG. 11 is similar to the cylinder head of FIG. 3 of the first embodiment and has many equivalent configurations. Therefore, the same components are denoted by the same reference numerals, and detailed description thereof is omitted. In the present embodiment, the configuration of the intake cam pin 28 and the exhaust cam pin 29 for moving the intake cam carrier 13 and the exhaust cam carrier 14 in the axial direction thereof is different from that of the first embodiment. FIG. 12 shows a perspective view of the intake cam control shaft 24 as a representative. In the present embodiment, the intake cam pin 28 includes an intake cam pin head portion 28 a that contacts the intake end cam surface 22, and an intake cam pin connection portion 28 b that connects the intake cam pin head portion 28 a to the intake cam control shaft 24. Composed. Among these, the intake cam pin head portion 28a is a metal solid cylindrical body (however, short) similar to the intake cam pin 28 of the first embodiment. On the other hand, the intake cam pin connecting portion 28b is formed of, for example, a metal leaf spring or the like, and is arranged with its width direction directed toward the axial direction of the intake cam control shaft 24, that is, the moving direction of the intake cam carrier 13. Therefore, the intake cam pin coupling portion 28b can be elastically deformed in the radial direction of the intake cam carrier 13 (strictly speaking, only in the radial direction), and particularly the rigidity in the axial direction of the intake cam carrier 13, that is, the moving direction of the intake cam carrier 13. Is expensive. Similarly, the exhaust cam pin 29 includes an exhaust cam pin head portion 29a and an exhaust cam pin coupling portion 29b.

  Also in the present embodiment, as in the first embodiment, the intake cam control shaft 24 and the exhaust cam control shaft 25 are respectively replaced by the individual intake cam actuator 26 and the individual exhaust cam actuator 27 for each cylinder. Control rotation. However, as a modification of the present embodiment, the intake cam control shaft 24 for a plurality of cylinders and the exhaust cam control shaft 25 for a plurality of cylinders are rotated by one intake cam actuator 26 and one exhaust cam actuator 27, respectively. You may make it control. Extremely speaking, the intake cam control shafts 24 for all cylinders and the exhaust cam control shafts 25 for all cylinders are rotationally controlled by one intake cam actuator 26 and one exhaust cam actuator 27, respectively. It may be. As is well known, in an in-line four-cylinder engine as in this embodiment, when the first cylinder, the second cylinder, the third cylinder, and the fourth cylinder are defined from any one side in the cylinder row direction, The first cylinder, the third cylinder, the fourth cylinder, the second cylinder, etc. are ignited in this order. In a four-cycle engine, four strokes are completed by two rotations of the crankshaft. Therefore, in the four cylinders, the strokes are shifted from each other by 180 ° for each cylinder. In other words, the intake stroke is performed in any cylinder at any timing, and the exhaust stroke is performed in any cylinder at any timing. When the intake cam carrier 13 and the exhaust cam carrier 14 are moved in the axial direction and the intake cam 11 and the exhaust cam 12 are in contact with the intake rocker arm 15 and the exhaust rocker arm 16, respectively. It is not possible to switch when the is operating, i.e. during the intake or exhaust stroke. Specifically, the positions of the intake end cam crest 22b of the intake end cam surface 22 and the exhaust end cam crest 23b of the exhaust end cam surface 23 do not overlap with the intake stroke and the exhaust stroke, respectively. It is set as follows.

  Therefore, if the rotation of the intake cam control shaft 24 and the exhaust cam control shaft 25 for a plurality of cylinders is controlled by the single intake cam actuator 26 and the exhaust cam actuator 27, the intake cam carrier 13 of any cylinder is controlled. The intake cam pin 28 and the exhaust cam pin 29 are the outer peripheral surface of the intake end cam peak portion 22b and the exhaust end cam peak portion 23b, respectively, on the intake end cam surface 22 and the exhaust end cam surface 23 of the exhaust cam carrier 14. It contacts each of the outer peripheral surfaces. In such a case, in this embodiment, as shown in FIG. 13 representatively of the intake end cam surface 22 and the intake cam pin 28, the intake end cam crest 22b of the intake end cam surface 22 is inhaled on the outer peripheral surface. Even if the intake cam pin head portion 28 a of the cam pin 28 contacts, the intake cam pin coupling portion 28 b bends in the radial direction of the intake cam carrier 13. Thereafter, if the intake cam carrier 13 rotates in the clockwise direction in FIG. 13, the intake cam pin head portion 28a of the intake cam pin 28 faces the intake end cam base surface 22a of the intake end cam surface 22, so that state Thus, the intake cam pin head portion 28a is accommodated in the intake end cam base surface 22a. After the storage, the intake cam carrier 13 is moved in the axial direction as in the description of FIGS. 7 to 10 of the first embodiment. This operation is the same in the exhaust cam pin head portion 29a and the exhaust cam pin connecting portion 29b of the exhaust cam pin 29.

  As described above, in the variable valve operating apparatus for a vehicle engine according to the present embodiment, in addition to the effects of the first embodiment, each of the intake cam carrier 13 for a plurality of cylinders and the exhaust cam carrier 14 for a plurality of cylinders is used as one intake. When the cam control shaft 24 and one exhaust cam control shaft 25 are to be moved in the axial direction, the intake cam pin 28 and the exhaust cam pin 29 are respectively connected to the intake end cam crest 22b of the intake end cam surface 22 and Even when the respective exhaust timings of the exhaust cam pins 28 and the exhaust cam pins 29 are in contact with the outer peripheral surfaces of the exhaust cam portions 23b of the exhaust cam portion 23 and the movement timings of the intake cam pins 28 and exhaust cam pins 29 deviate from the optimum switching timing, The intake cam pin head portion 28a and the exhaust cam pin head portion 29a, which are in contact with the intake end cam surface 22 and the exhaust end cam surface 23, respectively, and the intake cam control shaft 24 and By connecting the exhaust cam control shaft 25 with the intake cam pin connecting portion 28b and the exhaust cam pin connecting portion 29b, which can be elastically deformed only in the radial direction of the intake cam carrier 13 and the exhaust cam carrier 14, respectively, Each of the cam pin connecting portion 28b and the exhaust cam pin connecting portion 29b bends in the radial direction of each of the intake cam carrier 13 and the exhaust cam carrier 14, thereby allowing a shift in the movement timing of each of the intake cam pin 28 and the exhaust cam pin 29. .

  In the above embodiment, the variable valve device of the present invention is applied to the valve mechanism of both the intake and exhaust systems. However, the variable valve device of the present invention is applied only to one of the intake and exhaust systems, particularly to the intake system. May be.

  Although the embodiments of the present invention have been disclosed above, it will be apparent to those skilled in the art that changes can be made without departing from the scope of the present invention. All such modifications and equivalents are intended to be included in the following claims.

DESCRIPTION OF SYMBOLS 1 Variable valve operating apparatus 2 Engine 3 Cylinder head 4 Cylinder head main body 5 Cylinder head cover 6 Intake cam shaft 7 Exhaust cam shaft 8 Cam housing 9 Lower cam housing 10 Upper cam housing 11 Intake cam 11a 1st intake cam 11b 2nd intake cam 12 Exhaust cam 12a First exhaust cam 12b Second exhaust cam 13 Intake cam carrier 14 Exhaust cam carrier 15 Intake rocker arm 16 Exhaust rocker arm 17 Intake valve 18 Intake lash adjuster 19 Exhaust valve 20 Exhaust lash adjuster 21 Valve spring 22 Intake end cam surface 23 Exhaust end cam surface 24 Intake cam control shaft 25 Exhaust cam control shaft 26 Intake cam actuator 27 Exhaust cam actuator 28 Intake cam pin 28a Intake cam pin head portion 28b Intake cam Pin connection part 29 Exhaust cam pin 29a Exhaust cam pin head part 29b Exhaust cam pin connection part 31 Land part 32 Hemispherical hole 33 Through hole 34 Ball 35 Spring 36 Plug (blind plug)

Claims (2)

A variable valve operating device for a vehicle engine that achieves different valve operating characteristics by switching a plurality of cams,
A cam carrier that is formed in a cylindrical shape surrounding the camshaft, rotates integrally with the camshaft, and is movable in the axial direction of the camshaft;
A plurality of cams having different valve operating characteristics and arranged on an outer periphery of the cam carrier so as to be adjacent to each other in the axial direction of the cam carrier;
An end cam surface disposed at each of both axial ends of the cam carrier and forming a pair and having an elevation difference in the axial direction of the cam carrier;
A control shaft disposed on a side in a radial direction of the cam shaft and rotatable about an axis parallel to the cam shaft;
The camshaft is attached to the control shaft with a phase difference in the rotation direction of the control shaft, and an outer peripheral surface is selectively brought into contact with any one of the pair of end cam surfaces to move the cam carrier in the axial direction. A variable valve operating apparatus for a vehicle engine comprising a pair of pins. The pin is
A head portion in contact with the end cam surface;
2. The vehicle engine according to claim 1, further comprising a connecting portion that is formed of a material that is elastically deformable in a radial direction of the cam carrier and that connects the head portion to the control shaft. Variable valve gear.

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