JP2005226541A - Variable movable valve mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily replace a roller having influence of a working angle and/or a lift quantity of a valve element in a variable movable valve mechanism. <P>SOLUTION: This variable movable valve mechanism has a first arm member 24 and a second arm member 26 having the function for changing the working angle and the lift quantity in response to a rotational position of a control shaft 40; and has a slide roller 50 synchronizing with rotation of a cam 54 and rocking around a rotary shaft 46 for changing a position in response to the rotational position of the control shaft 40; and has a rocking arm having a side surface part arranged in a position respectively closely adjacent to both end parts of a roller shaft 50b of the slide roller 50. When a control shaft turning angle θ<SB>C</SB>falls within an ordinary use range, the side surface part of the rocking arm 22 overlaps with a roller 50a, and when the control shaft 40 rotates by exceeding the ordinary use range of the control shaft turning angle θ<SB>C</SB>, the roller 50a becomes attachable and detachable without overlapping the side surface part of the rocking arm 22 with the roller 50a. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a variable valve mechanism, and more particularly to a variable valve mechanism for an internal combustion engine that can change the operating angle and / or lift amount of a valve body that opens and closes in synchronization with the rotation of a camshaft.

  Conventionally, as disclosed in, for example, Japanese Patent Application Laid-Open No. 2002-371816, a variable valve mechanism that includes a mechanism that changes a working angle and a lift amount of a valve body between a cam and a valve body is known. The variable valve mechanism includes a first intervening arm (swinging arm) that transmits a pressing force of the cam to push the valve body between the cam and the valve body, and a second intervening arm having a roller that contacts the cam. (Swinging roller part). The variable valve mechanism is configured such that the positional relationship between the cam and the roller changes according to the rotational position of the control shaft. When the positional relationship between the cam and the roller changes, the timing at which the first intervening arm pushes down the valve body and the push-down amount of the valve body with respect to the rotation of the cam can be changed. For this reason, according to the conventional variable valve mechanism, the operating angle and the lift amount of the valve body can be continuously changed by controlling the rotational position of the control shaft.

JP 2002-371816 A

  As described above, the roller affects the change in the working angle and lift amount of the valve body in accordance with the relative positional relationship with the cam. Therefore, in the mechanism having such a roller, the working angle of the valve element and the lift amount can be finely adjusted by changing the diameter of the roller. For this reason, in the variable valve mechanism, it is convenient that the roller that affects the operating angle and / or the lift amount of the valve body as described above can be easily replaced during assembly and maintenance.

  The present invention has been made to solve the above-described problems, and provides a variable valve mechanism that can easily replace a roller that affects the operating angle and / or lift amount of a valve body. Objective.

In order to achieve the above object, the first invention is provided between a control shaft whose rotational position is adjusted so as to change the operating angle and / or lift amount of the valve body within a predetermined variable range, and the cam and the valve body. A variable valve mechanism that includes a transmission mechanism that transmits a pressing force of a cam to the valve body,
The transmission mechanism has a function of changing the working angle and / or the lift amount according to the rotational position of the control shaft, a roller that moves within a predetermined range in synchronization with the rotation of the cam, and the rotation of the control shaft A variable mechanism for changing the moving range of the roller according to the position, and a guide member having side portions provided at positions close to both ends of the roller,
When the rotation position of the control shaft is within the normal use range, the side surface portion overlaps the roller, and when the control shaft rotates beyond the normal use range, the side surface portion and the roller The rollers can be attached and detached without overlapping.

In a second aspect based on the first aspect, the transmission mechanism includes a swing arm that transmits the pressing force of the cam to the valve body by swinging in synchronization with the rotation of the cam.
The side surface portion is a part of the swing arm.

In a third aspect based on the first aspect, the transmission mechanism includes a roller contact surface that contacts the roller.
The guide member is a member attached to the roller contact surface.

  According to a fourth aspect of the present invention, in any one of the first to third aspects of the present invention, when the cam and the transmission mechanism are not in contact with each other when mounted on the internal combustion engine, the fourth aspect exceeds the normal use range. The roller is configured to be detachable when the control shaft is rotated.

  According to the first aspect of the invention, during engine operation, the rotational position of the control shaft is within the normal use range, so that the roller moves within a range in which movement of the roller shaft in the axial direction is restricted by the side surface of the guide member. It will be. When the control shaft is rotated beyond the normal use range, the roller shaft can be attached and detached without being restricted by the guide member. For this reason, according to the present invention, it is possible to prevent the roller shaft from coming off during engine operation, and at the time of assembly or maintenance, the roller can be easily replaced by moving the roller outside the regulation range of the guide member. can do. Furthermore, the roller of this invention changes the working angle and / or lift amount of a valve body with the position. For this reason, according to the present invention, by changing to a roller having a different diameter, the positional relationship between the roller and the member with which the roller abuts changes, and as a result, the operating angle and / or lift amount of the valve body is adjusted. be able to.

  According to the second aspect of the present invention, it is possible to prevent the roller shaft from coming off during engine operation without performing processing for preventing the roller shaft from coming off or adding a roller shaft coming-out preventing member.

  According to the third aspect of the invention, the roller shaft can be prevented from coming off during engine operation regardless of the positional relationship between the swing arm and the roller, that is, regardless of the valve system specifications, and during assembly or maintenance. The roller can be easily replaced.

  According to the fourth aspect of the invention, the roller can be easily replaced while the variable valve mechanism is mounted on the internal combustion engine.

  Embodiments of the present invention will be described below with reference to the drawings. In addition, the same code | symbol is attached | subjected to the element which is common in each figure, and the overlapping description is abbreviate | omitted.

Embodiment 1 FIG.
[Configuration of variable valve mechanism]
FIG. 1 is a perspective view of a main part of a variable valve mechanism 10 according to Embodiment 1 of the present invention. The variable valve mechanism shown in FIG. 1 is a mechanism for driving a valve body of an internal combustion engine. Here, it is assumed that each cylinder of the internal combustion engine is provided with two intake valves and two exhaust valves. The configuration shown in FIG. 1 functions as a mechanism for driving two intake valves or two exhaust valves arranged in a single cylinder.

  The configuration shown in FIG. 1 includes two valve bodies 12 that function as intake valves or exhaust valves. A valve shaft 14 is fixed to each valve body 12. The end of the valve shaft 14 is in contact with a pivot provided at one end of the rocker arm 16. A biasing force of a valve spring (not shown) acts on the valve shaft 14, and the rocker arm 16 is biased upward by the valve shaft 14 that has received the biasing force. The other end of the rocker arm 16 is rotatably supported by a hydraulic lash adjuster 18. According to the hydraulic lash adjuster 18, the tappet clearance can be automatically adjusted by automatically adjusting the position in the height direction of the rocker arm by hydraulic pressure.

  A rocker roller 20 is disposed at the center of the rocker arm 16. A rocking arm 22 is disposed on the top of the rocker roller 20. Hereinafter, the structure around the swing arm 22 will be described with reference to FIG.

  FIG. 2 is an exploded perspective view of the first arm member 24 and the second arm member 26. The first arm member 24 and the second arm member 26 are both main components in the configuration shown in FIG. The swing arm 22 described above is a part of the first arm member 24 as shown in FIG.

  That is, as shown in FIG. 2, the first arm member 24 is a member integrally including two swing arms 22 and a roller contact surface 28 sandwiched between them. The two swing arms 22 are provided corresponding to the two valve bodies 12, respectively, and are in contact with the rocker roller 20 (see FIG. 1) described above.

  The first arm member 24 is provided with a bearing portion 30 that is open so as to penetrate the two swing arms 22. Each of the swing arms 22 is provided with a concentric circle portion 32 and a pressing portion 34 on the surface in contact with the rocker roller 20. The concentric circle portion 32 is provided such that the contact surface with the rocker roller 20 forms a concentric circle with the bearing portion 30. On the other hand, the pressing portion 34 is provided such that the distance from the center of the bearing portion 30 increases as the distal end portion thereof is increased.

  The second arm member 26 includes a non-oscillating portion 36 and an oscillating roller portion 38. The non-oscillating part 36 is provided with a through hole, and the control shaft 40 is inserted into the through hole. Furthermore, a fixing pin 42 is inserted into the non-oscillating portion 36 and the control shaft 40 to fix the relative positions of both. For this reason, the non-oscillating part 36 and the control shaft 40 function as an integral structure.

  The swing roller unit 38 includes two side walls 44. These side walls 44 are connected to a non-oscillating portion 36 through a rotation shaft 46 so as to be rotatable. A cam contact roller 48 and a slide roller 50 are disposed between the two side walls 44. The cam contact roller 48 and the slide roller 50 can freely rotate while being sandwiched between the side walls 44.

  The control shaft 40 described above is a member that is rotatably held by a cylinder head (not shown), and the first arm member 24 is a member that is held by the control shaft 40 via the bearing portion 30. That is, the control shaft 40 is a member that should be integrated with the non-oscillating portion 36 while being inserted into the bearing portion 30. In order to satisfy this requirement, the non-oscillating portion 36 (that is, the second arm member 26) is positioned between the two oscillating arms 22 of the first arm member 24 before being fixed to the control shaft 40. . The control shaft 40 is inserted so as to pass through the two bearing portions 30 and the non-oscillating portion 36 in a state where the alignment is performed. Thereafter, a fixing pin 42 is attached to fix the control shaft 40 and the non-oscillating portion 36. As a result, the first arm member 24 can freely rotate around the control shaft 40, the non-oscillating portion 36 is integrated with the control shaft 40, and the oscillating roller portion 38 is non-oscillating portion 36. A mechanism capable of swinging with respect to is realized.

  When the first arm member 24 and the second arm member 26 are assembled as described above, the relative angle between the first arm member 24 and the control shaft 40, that is, the first arm member 24 and the non-oscillating portion 36. In the range where the relative angle satisfies the predetermined condition, the slide roller 50 of the swing roller unit 38 can contact the roller contact surface 28 of the first arm member 24. Then, when the first arm member 24 is rotated around the control shaft 40 within a range that satisfies the predetermined condition while maintaining the contact between both, the slide roller 50 rolls along the roller contact surface 28. Can move. The variable valve mechanism of the present embodiment opens and closes the valve body 12 with its rolling. The operation will be described in detail later with reference to FIG. 3 and FIG.

  FIG. 1 shows a state in which the first arm member 24, the second arm member 26, and the control shaft 40 are assembled in the above-described procedure. In this state, the positions of the first arm member 24 and the second arm member 26 are regulated by the position of the control shaft 40. The control shaft 40 is fixed to a fixing member such as a cylinder head via a bearing (not shown) so that the above-described conditions are satisfied, that is, the rocker roller 20 of the rocker arm 16 is in contact with the swing arm 22. ing.

  An actuator (not shown) is connected to the control shaft 40. This actuator can rotate the control shaft 40 within a predetermined angle range. The state shown in FIG. 1 shows a state in which the rotation angle of the control shaft 40 is adjusted to a range that satisfies the above-described predetermined condition by the actuator, and the slide roller 50 is brought into contact with the roller contact surface 28. Yes.

  The variable valve mechanism 10 of this embodiment also includes a camshaft 52 that rotates in synchronization with the crankshaft. A cam 54 provided for each cylinder of the internal combustion engine is fixed to the camshaft 52. In the state shown in FIG. 1, the cam 54 is in contact with the cam contact roller 48 and restricts the upward movement of the swing roller portion 38. That is, in the state shown in FIG. 1, the roller contact surface 28 of the first arm member 24 is mechanically connected to the cam 54 via the cam contact roller 48 and the slide roller 50 of the swing roller portion 38. Is realized.

  According to the state described above, when the cam nose presses the cam contact roller 48 as the cam 54 rotates, the force is transmitted to the roller contact surface 28 via the slide roller 50. The slide roller 50 can continue to transmit the acting force of the cam 54 to the first arm member 24 while rolling on the roller contact surface 28. As a result, the first arm member 24 rotates around the control shaft 40, the rocker arm 22 pushes down the rocker arm 16, and the valve body 12 is given movement in the valve opening direction. As described above, the variable valve mechanism 10 can actuate the valve body 12 by transmitting the acting force of the cam 54 to the roller contact surface 28 via the cam contact roller 48 and the slide roller 50. it can.

[Operation of variable valve mechanism]
Next, the operation of the variable valve mechanism 10 according to the first embodiment of the present invention will be described with reference to FIGS.

  The variable valve mechanism 10 configured as described above is configured so that the cam 54 and the roller contact surface 28 are mechanically connected via the cam contact roller 48 and the slide roller 50 in order to maintain the lost state. A motion spring 56 is provided. As shown in FIGS. 3 and 4, the lost motion spring 56 urges the rear end portion of the roller contact surface 28 with its upper end fixed to a cylinder head or the like. The urging force of the lost motion spring 56 acts as a force that the roller contact surface 28 urges the slide roller 50 upward, and further as a force that presses the cam contact roller 48 against the cam 54. As a result, the variable valve mechanism 10 can maintain a state in which the cam 54 and the roller contact surface 28 are mechanically connected, as shown in FIG. 3 or FIG.

  FIG. 3 shows a state in which the variable valve mechanism 10 operates to give a small lift to the valve body 12. Hereinafter, this operation is referred to as “small lift operation”. More specifically, FIG. 3A shows a state in which the valve body 12 is closed during the small lift operation, and FIG. 3B shows that the valve body 12 is opened during the small lift operation. The state of speaking is shown respectively.

In FIG. 3A, the symbol θ _C is a parameter that represents the rotational position of the control shaft 40. Hereinafter, the parameter is referred to as “control shaft rotation angle θ _C ”. Here, for the sake of convenience, an angle formed by the axial direction of the fixing pin 42 that fixes the control shaft 40 and the non-oscillating portion 36 and the vertical direction is defined as a control shaft rotation angle θ _C. In FIG. 3A, the symbol θ _A is a parameter representing the rotational position of the swing arm 22. Hereinafter, the parameter is referred to as “arm rotation angle θ _A ”. For convenience, and to define the angle between the straight line and the horizontal direction connecting the center of the tip portion and the control shaft 40 of the swing arm 22 and the arm rotation angle theta _A.

In the variable valve mechanism 10, the rotation position of the swing arm 22, that is, the arm rotation angle θ _A is determined by the position of the slide roller 50. Further, the position of the slide roller 50 is determined by the position of the rotating shaft 46 of the swing roller unit 38 and the position of the cam contact roller 48. In the range in which the contact between the cam contact roller 48 and the cam 54 is maintained, as the rotation shaft 46 rotates counterclockwise in FIG. 3, that is, as the control shaft rotation angle θc increases, the slide roller 50 increases. The position changes upward. Therefore, in the variable valve mechanism 10, the larger the control shaft rotation angle theta _C is, a phenomenon occurs that the arm rotation angle theta _A decreases.

In the state shown in FIG. 3A, the control shaft rotation angle θ _C is within a range in which the cam contact roller 48 can maintain contact with the cam 54, that is, the cam 54 moves upward of the cam contact roller 48. It is almost the maximum value that can be regulated. Therefore, in the state shown in FIG. 3A, the arm rotation angle θ _A is almost the minimum value. In this case, the variable valve mechanism 10 is configured such that the substantially center of the concentric circular portion 32 of the swing arm 22 is in contact with the rocker roller 20 of the rocker arm 16 and, as a result, the valve body 12 is closed. Yes. Hereinafter, the arm rotation angle θ _A in this case is referred to as “reference arm rotation angle θ _A0 during small lift”.

When the cam 54 rotates from the state shown in FIG. 3A, the cam contact roller 48 is pressed by the cam nose and moves in the direction of the control shaft 40 as shown in FIG. Since the distance from the rotation shaft 46 to the slide roller 50 of the oscillating roller portion 38 does not change, the roller contact surface 28 rolls on the surface when the cam contact roller 48 approaches the control shaft 40. It is pushed down by the slide roller 50. As a result, the swing arm 22 is rotated in the direction of arm rotation angle theta _A increases, the contact point between the swing arm 22 and rocker roller 20, moves from the concentric portion 32 to the pressing portion 34.

In the small lift operation, the reference arm rotation angle θ _A0 is set to a small value as described above. Therefore, the maximum value of the arm rotation angle theta _A due to the rotation of the cam 54 also becomes a relatively small value in the case of the small lift operation. Hereinafter, the maximum value is referred to as “maximum arm rotation angle θ _AMAX during small lift”. The valve body 12 has a maximum lift when the arm rotation angle θ _A reaches the maximum arm rotation angle θ _AMAX . As shown in FIG. 3B, the variable valve mechanism 10 has a slight contact point between the rocker roller 20 and the swing arm 22 when the maximum arm rotation angle θ _AMAX during a small lift occurs. 34, and as a result, a slight lift is generated in the valve body 12. Therefore, according to the variable valve mechanism 10, a small lift can be given to the valve body 12 in synchronization with the rotation of the cam 54 by performing the small lift operation described above.

  In this case, the period during which the acting force of the cam 54 actually pushes down the valve body 12, that is, the period during which the valve body 12 is not closed as the cam 54 rotates (crank angle width) is also relatively small. (This period is hereinafter referred to as “working angle”). Therefore, according to the variable valve mechanism 10, the operating angle of the valve body 12 can be reduced by performing a small lift operation.

  FIG. 4 shows a state in which the variable valve mechanism 10 is operating so as to give a large lift to the valve body 12. Hereinafter, this operation is referred to as “large lift operation”. More specifically, FIG. 4A shows a state in which the valve body 12 is closed in the process of the large lift operation, and FIG. 4B shows that the valve body 12 is opened in the process of the large lift operation. The state of speaking is shown respectively.

When performing a large lift operation, as shown in FIG. 4A, the control shaft rotation angle θ _C is adjusted to a sufficiently small value. As a result, when the large lift operation is performed, the arm rotation angle θ _A when not lifted, that is, the reference arm rotation angle θ _A0 is set to a sufficiently large value within a range in which the slide roller 50 does not fall off the roller contact surface 28. The The variable valve mechanism 10 is configured such that the contact point between the swing arm 22 and the rocker roller 20 is located at the end of the concentric circle portion 32 at the reference arm rotation angle θ _A0 . For this reason, also in the case of a large lift operation, the valve body 12 is maintained in a closed state.

When the cam 54 from the state shown in FIG. 4 (A) is rotated, as shown in FIG. 4 (B), the cam contact roller 48 is pressed against the cam nose, rocking in a direction arm rotation angle theta _A increases The moving arm 22 rotates. As a result, the contact point between the swing arm 22 and the rocker roller 20 shifts from the concentric circle portion 32 to the pressing portion 34. In the case of the large lift operation, the reference arm rotation angle θ _A0 is set to a large value as described above. Therefore, the maximum arm rotation angle θ _AMAX generated along with the rotation of the cam 54 is also set to a large value. As shown in FIG. 4B, the variable valve mechanism 10 has a sufficient contact point between the rocker roller 20 and the swing arm 22 when such a maximum arm rotation angle θ _AMAX occurs. It is comprised so that it may become the position which entered 34. Therefore, according to the variable valve mechanism 10, a large lift and a large working angle can be given to the valve body 12 in synchronization with the rotation of the cam 54 by performing the large lift operation described above.

Next, with reference to FIG. 5 thru | or FIG. 7, the characteristic part of the variable valve mechanism 10 of this embodiment is demonstrated.
FIG. 5 is a schematic view showing the structure of the slide roller 50 of the variable valve mechanism 10. The variable valve mechanism 10 of the present embodiment is characterized by the slide roller 50 and the surrounding structure. That is, as shown in FIG. 5, the slide roller 50 includes a roller 50a that contacts the roller contact surface 28 of the first arm member 24 and a roller shaft 50b that is detachably inserted into the roller 50a. ing. Further, in the variable valve mechanism 10 of the present embodiment, the side surface portion 22a of the swing arm 22 is disposed at positions close to both ends of the roller shaft 50b so as to cover the roller shaft 50b from both sides.

FIG. 6 is a view showing the variable valve mechanism 10 in which the cam 54 and the roller contact surface 28 are mechanically connected. As described above, the variable valve mechanism 10 of the present embodiment changes the reference arm rotation by changing the control shaft rotation angle θ _C while the cam 54 and the roller contact surface 28 are mechanically coupled. The angle θ _A0 is changed, and as a result, the operating angle and the lift amount applied to the valve body 12 can be changed. Hereinafter, the setting range of the control shaft rotation angle θ _C for controlling the operating angle and lift amount given to the valve body 12 by the variable valve mechanism 10 within a predetermined variable range is referred to as “normal use range of the control shaft rotation angle θ _C. ".

The slide roller 50 rolls along the roller contact surface 28 (in the arrow direction in FIG. 6) in synchronization with the rotation of the cam. Position and the rolling ranges slide roller 50 contacts the roller contact surface 28 is a changes in accordance with the value of the control shaft rotation angle theta _C, the control shaft rotation angle theta _C is within the normal use range For some time, the slide roller 50 rolls on the roller contact surface 28. The variable valve mechanism 10 of the present embodiment is configured such that both sides of the roller shaft 50 b are covered with the swing arm 22 as long as the slide roller 50 rolls on the roller contact surface 28. That is, the swing arm 22 is in the normal use range of the control shaft rotation angle theta _C, and has a function of restricting the axial movement of the roller shaft 50b. Thus, in the variable valve mechanism 10, at least a part of the rolling roller shaft 50 b swings when viewed from the axial direction of the slide roller 50 within the normal use range of the control shaft rotation angle θ _C. The relationship between the swing arm 22 and the roller contact surface 28 is determined so as to always overlap the side surface portion 22 a of the arm 22.

In the variable valve mechanism 10 of the present embodiment, as described above, the reference arm rotation angle θ _A0 representing the reference position of the swing arm 22 is determined by the position of the slide roller 50. Accordingly, when the diameter of the roller 50a in contact with the roller contact surface 28 is changed, the operating angle and the lift amount of the valve body 12 change. For this reason, when the slide roller 50 is configured to be easily replaceable, it is possible to easily finely adjust the operating angle and lift amount of the valve body 12 when the variable valve mechanism 10 is assembled or maintained. It becomes. Therefore, the variable valve mechanism 10 of the present embodiment is configured so that the sliding roller 22 reaches a position where the side surface portion 22a of the swing arm 22 does not overlap the roller shaft 50b, that is, a position where the restriction of the roller shaft 50b by the swing arm 22 is eliminated. By moving 50, the roller shaft 50b is removed from the rocking roller portion 38 so that the slide roller 50 can be replaced.

FIG. 7 is a diagram for explaining a method for replacing the slide roller 50. As shown in FIG. 7, the variable valve mechanism 10 of this embodiment, to a region beyond the normal use range of the control shaft rotation angle theta _C, clockwise in direction (Fig. 7 in which the control shaft rotation angle theta _C increases ), The cam contact roller 48 is not restricted by the cam 54, and the swing roller portion 38 can rotate around the rotation shaft 46 of the second arm member 26. . Then, if the rocking roller portion 38 is rotated clockwise, the roller shaft 50b can be moved to a position where the rocking arm 22 is not restricted. In the slide roller 50 according to the present embodiment, since the roller shaft 50b is detachable from the roller 50a, the roller shaft 50b can be removed by moving the roller shaft 50b to a position where it is not restricted by the swing arm 22. The roller 50a can be replaced.

As described above, according to the variable valve mechanism 10 of the present embodiment, in the normal use range of the control shaft rotation angle theta _C, or subjected to processing for removal prevention of the roller shaft 50b, the roller shaft 50b The roller shaft 50b of the slide roller 50 can be prevented from coming off without the need to add a slip-off preventing member. The slide roller 50 can be easily replaced by moving the roller shaft 50b to a position where it is not restricted by the swing arm 22.

  In the variable valve mechanism, the valve opening characteristics of the valve body 12 may vary between cylinders due to initial tolerances and assembly tolerances of individual members. According to the variable valve mechanism 10 of the present embodiment, in such a case, the operating angle and lift of the valve body 12 between the cylinders can be changed by replacing the slide roller 50 by the above method and appropriately changing the diameter thereof. The amount variation can be easily adjusted.

  Incidentally, in the first embodiment described above, the movement of the slide roller 50 in the axial direction of the roller shaft 50b is restricted by the side surface portion 22a of the swing arm 22, or the restriction is released, so that the roller shaft 50b can be easily removed. However, the present invention is not limited to the slide roller 50 as long as it is a roller that affects the working angle and / or the lift amount of the valve body. That is, in the variable valve mechanism 10 of the present embodiment, the operating angle and lift amount of the valve body 12 can be finely adjusted by changing the diameter of the cam contact roller 48. Therefore, the cam contact roller 48 can be easily replaced by restricting the movement of the cam contact roller 48 in the axial direction or releasing the restriction by the same method as in the first embodiment. Also good.

  In the first embodiment described above, the roller 50a of the slide roller 50 is configured to be detachable from the roller shaft 50b, so that the roller 50a is not subject to the restriction by the side surface portion 22a of the swing arm 22. However, the roller of the present invention is not limited to a roller whose central axis is configured to be removable, and may be removable at a position that is not restricted by the side surface of the guide member. That's fine.

  In the first embodiment described above, the first arm member 24 and the second arm member 26 are the second arm excluding the slide roller 50 and / or the cam contact roller in the “transmission mechanism” in the first invention. The member 26 and the roller contact surface 28 correspond to the “variable mechanism” in the first invention.

Embodiment 2. FIG.
Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 8 is a view for explaining the configuration of the variable valve mechanism 60 of the present embodiment. FIG. 9 is a view for explaining the structure of the guide member 62 attached to the roller contact surface 66 shown in FIG. FIG. 10 is a view showing a state in which the guide member 62 is attached to the roller contact surface 66. More specifically, FIG. 10A shows a perspective view seen from the roller contact surface 64 side, FIG. 10B shows a cross-sectional view cut at the center of the roller contact surface 66, FIG. 10C shows a perspective view seen from the opposite direction of FIG.

  The variable valve mechanism 60 of the present embodiment is the same as the variable valve mechanism 10 of the first embodiment, except that the method for regulating the axial movement of the roller shaft 50b of the slide roller 50 is different. That is, as shown in FIG. 8, in the variable valve mechanism 60 of the present embodiment, the guide member 62 is in contact with the roller of the first arm member 64 so as to restrict the movement of the roller shaft 50 b of the slide roller 50 in the axial direction. Attached to the surface 66.

  As shown in FIGS. 8 and 9, the guide member 62 is attached to the roller contact surface 66 of the first arm member 64. The guide member 62 is installed so as to cover the roller shaft 50b of the slide roller 50 from both sides. For this reason, the guide member 62 can restrict the axial movement of the roller shaft 50 b of the slide roller 50 that rolls along the roller contact surface 66.

  As shown in FIGS. 9 and 10, the guide member 62 has a bottom surface portion 68 and two side surface portions 70 orthogonal to the bottom surface portion 68. A cut-and-raised portion 72 is provided on the side surface portion 70 of the guide member 62. A spring portion 74 is provided on the bottom surface portion 68 of the guide member 62. On the other hand, the roller contact surface 66 is formed with a recess 76 for engaging with the cut-and-raised portion 72 and the spring portion 74 of the guide member 62. According to such a configuration, the guide member 62 can be fixed to the roller contact surface 66 without rattling by the elastic force generated by the cut and raised portion 72 and the spring portion 74.

As described above, according to the variable valve mechanism 60 of the present embodiment, in the normal use range of the control shaft rotation angle theta _C, the side portions 70 of the guide member 62, exits the roller shaft 50b of the slide roller 50 Can be prevented. Further, even when the guide member 62 is attached, the slide is performed by moving the roller shaft 50b to a position where the restriction by the guide member 62 is eliminated by the same method as the variable valve mechanism 10 of the first embodiment. The roller 50 can be easily replaced.

  Depending on the specifications of the valve train, the arrangement may be such that the roller shaft 50b of the slide roller 50 and the swing arm 22 do not overlap. According to the variable valve mechanism 60 of this embodiment, regardless of the positional relationship between the roller shaft 50b and the swing arm 22, that is, regardless of other requirements that determine the specifications of the valve system, A configuration that can be easily exchanged can be realized.

  Further, according to the variable valve mechanism 60 of the present embodiment, as in the case of the first embodiment, by changing the diameter of the slide roller 50, the operating angle of the valve body 12 and the variation in the lift amount between the cylinders are changed. Can be easily fine-tuned. Furthermore, if a variable valve mechanism similar to the variable valve mechanism 60 including the guide member 62 is provided for each single valve body 12, the variation in operating angle and lift amount between the valve bodies can be finely adjusted. It becomes possible.

Embodiment 3 FIG.
Next, Embodiment 3 of the present invention will be described with reference to FIG. The guide member of the present invention can also be applied to the valve train layout of the third embodiment. FIG. 11 is a view for explaining the configuration of the variable valve mechanism 80 of the present embodiment.

  The variable valve mechanism 80 of the present embodiment is the same as the variable valve mechanism 60 of the second embodiment, except that the specifications of the valve system are different. That is, as shown in FIG. 11, the variable valve mechanism 80 of the present embodiment differs from the mechanism of the second embodiment in the positional relationship between the cam 82 and the valve body 84, and the first arm is associated with the change. The roller contact surface 88 of the member 86 has a configuration arranged on the upper side with respect to the swing arm 90.

As shown in FIG. 11, a guide member 92 is attached to the first arm member 86 in the variable valve mechanism 80. The guide member 92 has the same structure as the guide member 62 of the second embodiment. Therefore, according to the variable valve mechanism 80 of the present embodiment, in the normal use range of the control shaft rotation angle theta _C, by the guide member 92, it is possible to prevent the omission of the roller shaft 94b. Further, according to the same method as in the second embodiment, the slide roller 94 can be easily replaced in a state where the variable valve mechanism 80 is mounted on the internal combustion engine.

It is a perspective view of the principal part of the variable valve mechanism of Embodiment 1 of this invention. It is a disassembled perspective view of the 1st arm member and the 2nd arm member which are the components of the variable valve mechanism shown in FIG. It is a figure which shows a mode in case the variable valve mechanism shown in FIG. 1 performs a small lift operation | movement. It is a figure which shows a mode in case the variable valve mechanism shown in FIG. 1 performs a big lift operation | movement. It is the schematic which shows the structure of the slide roller which is the characterizing part of the variable valve mechanism of Embodiment 1 of this invention. It is a figure which shows the state with which the cam and the roller contact surface were mechanically connected in the variable valve mechanism of Embodiment 1 of this invention. It is a figure for demonstrating the replacement | exchange method of the slide roller shown in FIG. It is a figure for demonstrating the structure of the variable valve mechanism of Embodiment 2 of this invention. It is a figure for demonstrating the structure of the guide member used in Embodiment 2 of this invention. It is a figure which shows the state in which the guide member shown in FIG. 9 was attached to the roller contact surface. It is a figure for demonstrating the structure of the variable valve mechanism of Embodiment 3 of this invention.

Explanation of symbols

10, 60, 80 Variable valve mechanism 12, 84 Valve body 16 Rocker arm 20 Rocker roller 22, 90 Oscillating arm 22a Side surface parts 24, 64, 86 First arm member 26 Second arm members 28, 66, 88 Roller contact Contact surface 32 Concentric circle portion 34 Press portion 36 Non-oscillating portion 38 Oscillating roller portion 40 Control shaft 46 Rotating shaft 48 Cam contact roller 50, 94 Slide roller 50a Roller 50b, 94b Roller shaft 54, 82 Cam 62, 92 Guide member 70 Side portion θ _C Control shaft rotation angle θ _A Arm rotation angle

Claims (4)

A control shaft whose rotational position is adjusted so as to change the working angle and / or lift amount of the valve body within a predetermined variable range is interposed between the cam and the valve body, and the cam pressing force is transmitted to the valve body. A variable valve mechanism comprising a transmission mechanism for
The transmission mechanism has a function of changing the working angle and / or the lift amount according to the rotational position of the control shaft, a roller that moves within a predetermined range in synchronization with the rotation of the cam, and the rotation of the control shaft A variable mechanism for changing the moving range of the roller according to the position, and a guide member having side portions provided at positions close to both ends of the roller,
When the rotation position of the control shaft is within the normal use range, the side surface portion overlaps the roller, and when the control shaft rotates beyond the normal use range, the side surface portion and the roller A variable valve mechanism characterized in that the rollers can be attached and detached without overlapping. The transmission mechanism includes a swing arm that transmits the pressing force of the cam to the valve body by swinging in synchronization with the rotation of the cam.
The variable valve mechanism according to claim 1, wherein the side portion is a part of the swing arm. The transmission mechanism includes a roller contact surface in contact with the roller,
The variable valve mechanism according to claim 1, wherein the guide member is a member attached to the roller contact surface. The roller is configured to be detachable when the control shaft is rotated beyond the normal use range to a position where the cam and the transmission mechanism do not come into contact with each other when mounted on the internal combustion engine. The variable valve mechanism according to any one of claims 1 to 3, wherein the variable valve mechanism is provided.

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