JP2008196314A - Variable valve gear - Google Patents

Abstract

The present invention relates to a variable valve operating apparatus in which a working angle of a valve is variable, and when performing an operation for finely adjusting the working angle, it is possible to reduce the difficulty of the adjustment work due to the biasing force of a lost motion spring. The purpose is to optimize the arrangement of the lost motion springs to make the device compact.
A variable valve operating apparatus includes a swing arm, a variable mechanism that changes a swing range of the swing arm by rotating a control shaft, and an action for finely adjusting a valve operating angle. An angle adjustment mechanism 37 and a lost motion spring 30 that urges the swing arm 18 are provided. In a state where the urging force of the lost motion spring 30 is maximized, the operating angle adjusting mechanism 37 faces the lost motion spring 30. In a state where the urging force of the lost motion spring 30 is minimized, the working angle adjustment mechanism 37 can be adjusted to face the external space.
[Selection] Figure 6

Description

  The present invention relates to a variable valve gear.

  Japanese Patent Application Laid-Open No. 2006-161730 discloses a variable valve operating apparatus that can change the operating angle of a valve of an internal combustion engine, and is interposed between the drive cam of the internal combustion engine and the valve, with the rotation of the drive cam. A swing mechanism (swing cam arm) that swings and a control shaft, and a variable mechanism that changes the swing range of the swing member by rotating the control shaft and fine adjustment of the valve operating angle There is disclosed a variable valve operating apparatus including an adjusting mechanism for the purpose.

  In such a variable valve operating apparatus, there may be variations in valve operating angles between cylinders due to manufacturing errors and assembly errors of components. The adjustment mechanism is a mechanism for finely adjusting the operating angle of the valve by finely adjusting the mounting angle of the control member with respect to the control shaft, so that the operating angles are accurately aligned between the cylinders. Specifically, the adjustment mechanism disclosed in the above publication is the following mechanism. An insertion hole is provided in the control member, and a protruding portion having a smaller width in the circumferential direction than the insertion hole is disposed so as to protrude from the control shaft into the insertion hole. A gap is formed between the protruding portion and the left and right wall surfaces in the circumferential direction of the insertion hole, and an adjustment shim is disposed in each of the left and right gaps. By replacing the left and right adjustment shims with different shapes, the mounting angle of the control member to the control shaft can be adjusted.

JP 2006-161730 A

  Although not shown in the drawings of the above publication, the variable valve device as described above has a lost motion spring that biases the swing member toward the drive cam. The urging force of the lost motion spring acts in a direction to sandwich the adjustment shim. For this reason, in the conventional variable valve operating apparatus described above, the adjustment shim tends to be difficult to attach and detach because the adjustment shim is held with a strong force during the adjustment of the operating angle.

  Further, in order to make the variable valve operating apparatus as compact as possible, it is necessary to dispose the operating angle adjusting mechanism and the lost motion close to each other. However, if the positions of the lost motion spring and the operating angle adjusting mechanism are close, the lost motion spring becomes an obstacle when exchanging the adjustment shim, making it difficult to work. On the other hand, if the lost motion spring and the operating angle adjusting mechanism are arranged at positions separated from each other, the variable valve operating device is likely to be enlarged.

  The present invention has been made to solve the above-described problems. When performing a work for finely adjusting the operating angle in a variable valve operating apparatus that makes the operating angle of the valve variable, the biasing force of the lost motion spring is used. It is an object of the present invention to provide a variable valve operating apparatus that can alleviate the difficulty of adjustment work, and that can optimize the arrangement of the lost motion spring to make the apparatus compact.

In order to achieve the above object, a first invention is a variable valve operating apparatus in which a working angle of a valve of an internal combustion engine is variable.
A swinging member interposed between the drive cam of the internal combustion engine and the valve, and swinging with the rotation of the drive cam;
A variable mechanism that has a control shaft and changes the swing range of the swing member by rotating the control shaft;
An operating angle adjusting mechanism for finely adjusting the operating angle, which is installed to rotate integrally with the control shaft;
A lost motion spring that biases the swing member toward the drive cam;
With
In the first state where the rotational position of the control shaft is at a position where the urging force of the lost motion spring is maximized, the operating angle adjustment mechanism is opposed to the lost motion spring,
In the second state where the rotational position of the control shaft is at a position where the urging force of the lost motion spring is minimized, the working angle adjustment mechanism can be adjusted to face the external space. It is configured.

The second invention is the first invention, wherein
The lost motion spring is a torsion coil spring.

The third invention is the first invention, wherein
The lost motion spring is composed of a torsion coil spring, and its central axis is arranged in a posture parallel to the control axis,
In the first state, the working angle adjustment mechanism enters between the control shaft and the lost motion spring, and in the second state, the working angle adjustment mechanism moves between the control shaft and the lost motion spring. It is structured so as to come out from between.

According to a fourth invention, in any one of the first to third inventions,
The first state is a large working angle state, and the second state is a small working angle state.

According to a fifth invention, in any one of the first to third inventions,
The internal combustion engine has a plurality of cylinders,
The first state is a large working angle state, the second state is a small working angle state,
In the small working angle state, the working angle adjusting mechanism is adjusted so that the working angles of the valves of the cylinders are aligned.

According to a sixth invention, in any one of the first to fifth inventions,
The variable mechanism is
A control member that rotates integrally with the control shaft;
An intermediate arm rotatably connected to the control member;
An intermediate member supported at the tip of the intermediate arm and disposed between the drive cam and the swing member;
Including
The working angle adjusting mechanism includes a shim that adjusts the mounting angle of the control member with respect to the control shaft, and finely adjusts the working angle by exchanging the shim with a different thickness. And

The seventh invention is the sixth invention, wherein
In the first state, the desorption direction of the shim faces the lost motion spring side, and in the second state, the desorption direction of the shim faces the external space side.

  According to the first invention, in the first state where the rotational position of the control shaft is at a position where the biasing force of the lost motion spring is maximized, the operating angle adjusting mechanism faces the lost motion spring, and the control shaft In the second state in which the rotation position of the lost motion spring is at a position where the urging force of the lost motion spring is minimized, the operating angle adjustment mechanism faces the external space and can be adjusted. Yes. According to such a variable valve operating apparatus, when the working angle adjusting mechanism is adjusted, the second state is set, so that the working angle adjusting mechanism can be operated in a state of facing the external space. . For this reason, a tool etc. can reach a working angle adjustment mechanism easily. Further, since the adjustment work can be performed in a state where the biasing force of the lost motion spring acting on the working angle adjustment mechanism is relatively small, the adjustment work can be easily performed. Further, according to the first aspect, in the first state, the operating angle adjustment mechanism faces the lost motion spring. That is, the lost motion spring is disposed in the vicinity of the operating angle adjustment mechanism. Thereby, a variable valve apparatus can be comprised compactly.

  According to the second invention, the lost motion spring is formed of a torsion coil spring. When the torsion coil spring is deformed, the angle of the arm only changes, and since there is no expansion / contraction like the compression coil spring, it is not necessary to secure a space for expansion / contraction, and the size of the spring itself is also It can be made smaller than the compression coil spring. For this reason, according to the second aspect of the present invention, the variable valve gear can be configured more compactly.

  According to the third aspect of the invention, the lost motion spring is constituted by a torsion coil spring, and is arranged in a posture in which the central axis is parallel to the control axis. When the torsion coil spring is deformed, the angle of the arm only changes, and since there is no expansion / contraction like the compression coil spring, it is not necessary to secure a space for expansion / contraction, and the size of the spring itself is also It can be made smaller than the compression coil spring. By using such a torsion coil spring as a lost motion spring and arranging the torsion coil spring in parallel with the control shaft, the variable valve operating apparatus can be configured more compactly. Further, according to the third invention, in the first state, the operating angle adjusting mechanism is interposed between the control shaft and the lost motion spring, and in the second state, the operating angle adjusting mechanism is controlled between the control shaft and the lost motion spring. It is configured to come out between. As a result, the lost motion spring can be arranged so that the space between the control shaft and the lost motion spring can be effectively utilized, so that the variable valve operating apparatus can be configured extremely compactly. In the second state, since the operating angle adjusting mechanism comes out between the control shaft and the lost motion spring, the adjusting operation of the operating angle adjusting mechanism can be easily performed.

  According to the fourth aspect, the first state corresponds to the large working angle state, and the second state corresponds to the small working angle state. Thereby, the operating angle adjusting mechanism can be adjusted in the small operating angle state. Since the small working angle state is set when the internal combustion engine is idling, the small working angle state is usually set when the internal combustion engine is stopped. For this reason, according to the fourth aspect of the present invention, when the adjustment operation of the working angle adjustment mechanism is performed, the procedure for turning the control shaft to a position where the adjustment operation can be performed after the internal combustion engine is stopped becomes unnecessary, and the control shaft can be rotated as it is. Adjustment work can be performed at the position. Furthermore, according to the fourth invention, there are the following advantages. When the working angle of the intake valve is large, the effect on the in-cylinder air amount is small even if the working angle is slightly different, but when the working angle of the intake valve is small, a slight difference in the working angle affects the in-cylinder air amount. A big influence. For this reason, in correcting the variation in the air amount between the cylinders, it is important that the operating angles of the respective cylinders are accurately aligned in the small operating angle state. According to the fourth invention, the adjustment operation of the operating angle adjusting mechanism of each cylinder is performed in the small operating angle state, and the operating angle of each cylinder is adjusted so as to be accurately aligned. In view of this, it is possible to correct the air amount variation between the cylinders with high accuracy.

  According to the fifth aspect, the first state corresponds to the large working angle state, and the second state corresponds to the small working angle state. Thereby, the operating angle adjusting mechanism can be adjusted in the small operating angle state. Since the small working angle state is set when the internal combustion engine is idling, the small working angle state is usually set when the internal combustion engine is stopped. For this reason, according to the fifth aspect of the present invention, when the adjustment operation of the working angle adjustment mechanism is performed, a procedure for turning the control shaft to a position where the adjustment operation can be performed after the internal combustion engine is stopped becomes unnecessary, and the control shaft can be rotated as it is. Adjustment work can be performed at the position. Furthermore, according to the fifth aspect, there are the following advantages. When the working angle of the intake valve is large, the effect on the in-cylinder air amount is small even if the working angle is slightly different, but when the working angle of the intake valve is small, a slight difference in the working angle affects the in-cylinder air amount. A big influence. For this reason, in correcting the variation in the air amount between the cylinders, it is important that the operating angles of the respective cylinders are accurately aligned in the small operating angle state. According to the fifth aspect of the invention, the adjustment operation of the operating angle adjusting mechanism of each cylinder is performed in the small operating angle state, and the operating angle of each cylinder is adjusted to be accurately aligned. In view of this, it is possible to correct the air amount variation between the cylinders with high accuracy.

  According to the sixth invention, in the working angle adjusting mechanism, the working angle can be adjusted with high accuracy by replacing the shim that adjusts the mounting angle of the control member with respect to the control shaft with a different thickness. .

  According to the seventh invention, in the first state, the detachment direction of the shim faces the lost motion spring side, and in the second state, the detachment direction of the shim faces the external space side. Thereby, in the 2nd state, the operation | work which replace | exchanges the shim of a working angle adjustment mechanism can be performed easily.

  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.
1 is a cross-sectional side view showing a variable valve apparatus according to Embodiment 1 of the present invention. Hereinafter, the variable valve operating apparatus 10 shown in FIG. 1 will be described as driving the intake valve 12 of the internal combustion engine, but the present invention can also be applied to a variable valve operating apparatus that drives an exhaust valve.

  The variable valve operating apparatus 10 includes a drive cam 14 provided on a camshaft 13 that is rotationally driven by a crankshaft of an internal combustion engine. The variable valve operating apparatus 10 has a control shaft 16 arranged in parallel to the cam shaft 13 and a control shaft drive mechanism (not shown) that can rotate the control shaft 16 within a predetermined angle range. is doing.

  The configuration of the control shaft drive mechanism is not particularly limited. For example, the control shaft drive mechanism includes a worm wheel fixed to one end of the control shaft 16, a worm gear meshing with the worm wheel, and a servo motor that rotationally drives the worm gear. be able to. In this case, the rotational position of the control shaft 16 can be controlled by controlling the direction and amount of rotation of the servo motor.

  Furthermore, the variable valve operating apparatus 10 has a swing arm (swing member) 18. The swing arm 18 is installed so as to be swingable about the control shaft 16. A slider surface 20 is formed on the swing arm 18 on the side facing the drive cam 14.

  A slider roller 22 is disposed between the swing arm 18 and the drive cam 14. The slider roller 22 is rotatably supported at the tip of the intermediate arm 24. A base end portion of the intermediate arm 24 is rotatably connected to a control member (control arm) 26 by a connecting shaft 27. The control member 26 is a member that rotates integrally with the control shaft 16. Therefore, when the control shaft 16 is rotated, the displacement is transmitted through the control member 26 and the intermediate arm 24, and the slider roller 22 moves.

  Specifically, when the control shaft 16 is rotated clockwise from the state shown in FIG. 1, the slider roller 22 moves away from the swing center of the swing arm 18 (that is, the center of the control shaft 16), and the swing arm 18. Move to the tip side. Then, when the control shaft 16 is rotated counterclockwise from the state where the slider roller 22 is on the tip side of the swing arm 18, the slider roller 22 is pulled by the intermediate arm 24 and approaches the center of the control shaft 16. . FIG. 1 shows a state in which the position of the slider roller 22 is close to the center of the control shaft 16.

  The slider surface 20 has a curved surface (for example, an arc surface) in which the distance from the center of the camshaft 13 gradually increases as it goes to the distal end side of the swing arm 18. A swing cam surface 28 is formed on the swing arm 18 on the side opposite to the slider surface 20.

  The swing arm 18 is urged clockwise by a lost motion spring 30 in FIG. The lost motion spring 30 is composed of a torsion coil spring. The lost motion spring 30 is arranged in such a posture that its central axis is parallel to the control shaft 16 and the cam shaft 13. The oscillating arm 18 is pressed against the slider roller 22 by the urging force of the lost motion spring 30, and the slider roller 22 is pressed against the drive cam 14.

  The variable valve operating apparatus 10 further includes a rocker arm 32 for pressing the valve shaft of the intake valve 12 in the lift direction. The rocker arm 32 is disposed below the swing arm 18 in FIG. A rocker roller 34 is rotatably attached to an intermediate portion of the rocker arm 32. The rocker roller 34 is in contact with the swing cam surface 28. One end of the rocker arm 32 is in contact with the valve shaft end of the intake valve 12, and the other end of the rocker arm 32 is supported by a hydraulic lash adjuster 36. The intake valve 12 is urged in a closing direction, that is, a direction in which the rocker arm 32 is pushed up by a valve spring (not shown). The rocker roller 34 is pressed against the swing cam surface 28 of the swing arm 18 by the biasing force and the hydraulic lash adjuster 36.

  In such a variable valve operating apparatus 10, when the drive cam 14 rotates, the cam lift of the drive cam 14 is transmitted to the swing arm 18 via the slider roller 22, so that the swing arm 18 swings.

  In the state shown in FIG. 1, that is, in the state where the slider roller 22 is close to the center of the control shaft 16, the cam lift of the drive cam 14 is transmitted to the swing arm 18 at a position close to the swing center of the swing arm 18. Will be. For this reason, the swing range (swing width) of the swing arm 18 is increased. As a result, the operating angle (and lift amount) of the intake valve 12 increases. Conversely, when the slider roller 22 is at a position far from the center of the control shaft 16, the cam lift of the drive cam 14 is transmitted to the swing arm 18 at a position far from the swing center of the swing arm 18. . For this reason, the swing range (swing width) of the swing arm 18 is reduced. As a result, the operating angle (and lift amount) of the intake valve 12 is reduced.

  In this manner, in the variable valve apparatus 10, the operating angle of the intake valve 12 can be continuously changed by rotating the control shaft 16 and moving the slider roller 22. That is, as the rotational position of the control shaft 16 is displaced clockwise in FIG. 1, the operating angle of the intake valve 12 can be reduced. Conversely, the rotational position of the control shaft 16 is counterclockwise in FIG. The greater the displacement is, the larger the operating angle of the intake valve 12 can be.

  2 and 3 are perspective views of the variable valve operating apparatus 10, respectively. In the present embodiment, two intake valves 12 are provided per cylinder of the internal combustion engine. As shown in FIGS. 2 and 3, in the variable valve operating apparatus 10, a swing arm 18 is separately provided for each of the two intake valves 12. On the other hand, the control member 26 and the intermediate arm 24 are shared by the two intake valves 12.

  As shown in FIGS. 2 and 3, the swing arm 18 is formed with a spring receiving portion 19. The arm 31 of the lost motion spring 30 presses the spring receiving portion 19 so that the swing arm 18 is urged clockwise in FIG. FIG. 3 shows a state where the lost motion spring is removed.

  Of the components of the variable valve operating apparatus 10, the cam shaft 13 and the control shaft 16 are shared by a plurality of cylinders of the internal combustion engine. On the other hand, the other components described above are provided for each cylinder.

  When an internal combustion engine equipped with such a variable valve operating apparatus 10 is assembled, the operating angle of the intake valve 12 is increased between cylinders due to manufacturing errors or assembly errors of components of the variable valve operating apparatus 10. Usually, some variation occurs. If there is a variation between cylinders in the operating angle of the intake valve 12, the amount of air in each cylinder varies, which may adversely affect the operation of the internal combustion engine. Therefore, the variable valve apparatus 10 includes a working angle adjustment mechanism 37 that can adjust the working angle of the intake valve 12 for each cylinder so that the variation in the working angle of the intake valve 12 between cylinders can be corrected. . Hereinafter, the configuration of the working angle adjustment mechanism 37 will be described.

  4 and 5 are perspective views showing an exploded state and an assembled state of the working angle adjusting mechanism 37, respectively. The operating angle adjusting mechanism 37 adjusts the operating angle of the intake valve 12 by finely adjusting the mounting angle of the control member 26 with respect to the control shaft 16.

  As shown in FIG. 4, the working angle adjustment mechanism 37 is configured by a control pin 48, an adjustment pin 50, a shim 60, a bolt 62, and a nut 64. The control pin 48 is inserted into a pin insertion hole 38 formed in the control shaft 16 and is disposed so as to protrude from the control shaft 16 in the radial direction. The control member 26 is formed with a control shaft insertion hole 40 into which the control shaft 16 is inserted, a pin insertion hole 42 formed in a direction orthogonal to the axial direction of the control shaft 16, and a direction parallel to the control shaft 16. A bearing hole 44 and a bearing hole 46 into which the connecting shaft 27 for connecting to the intermediate arm 24 is inserted are formed.

  A bolt insertion hole 66 through which the bolt 62 is inserted is formed in the control pin 48. The adjustment pin 50 has a substantially cylindrical shape (columnar shape). More specifically, the adjustment pin 50 has a shape in which a flat surface is formed by cutting the axial central portion of the cylinder. A screw hole 68 having a female screw that is screwed into the male screw portion of the bolt 62 is formed in the plane portion. The adjustment shim 60 is a member that is sandwiched between the control pin 48 and the adjustment pin 50. The adjustment shim 60 has a shape having a bifurcated portion, and is arranged so that the bifurcated portion straddles the bolt 62. A large number of adjustment shims 60 having different thicknesses are prepared and selected from them.

  When assembling such a working angle adjusting mechanism 37, first, the control shaft 16 is inserted into the control shaft insertion hole 40 of the control member 26. In FIG. 5, the illustration of the control shaft 16 is omitted. Next, the control pin 48 is inserted from the pin insertion hole 42 of the control member 26 and further inserted into the pin insertion hole 38 of the control shaft 16. Next, the adjustment pin 50 is inserted into the bearing hole 44. In this state, the adjustment pin 50 is rotatable in the bearing hole 44. Next, the bolt 62 is inserted into the bolt insertion hole 66 of the control pin 48 and further screwed into the screw hole 68 of the adjustment pin 50. Then, the bolt 62 is tightened with the adjustment shim 60 sandwiched between the control pin 48 and the adjustment pin 50. Further, the nut 64 is screwed onto the tip of the bolt 62 that protrudes through the screw hole 68 and is tightened. In this embodiment, by providing this nut 64, the screw hole 68 of the adjustment pin 50 and the nut 64 function as a double nut. Thereby, loosening of the bolt 62 can be prevented more reliably.

  By assembling the operating angle adjusting mechanism 37 in this way, the control member 26 is fixed to the control shaft 16 as shown in FIG. In such a working angle adjustment mechanism 37, the attachment angle of the control member 26 with respect to the control shaft 16 can be finely adjusted by replacing the adjustment shim 60 with one having a different thickness.

  That is, when the adjustment shim 60 is replaced with a thicker one, the attachment angle of the control member 26 with respect to the control shaft 16 changes slightly clockwise in FIG. As a result, the operating angle of the intake valve 12 is finely adjusted in the direction of decreasing. Conversely, when the adjustment shim 60 is replaced with a thin one, the mounting angle of the control member 26 with respect to the control shaft 16 changes slightly counterclockwise in FIG. As a result, the operating angle of the intake valve 12 is finely adjusted in the increasing direction.

  After assembly of the variable valve operating apparatus 10, adjustment is performed using the operating angle adjusting mechanism 37 as described above so that the operating angles of the intake valves 12 of the respective cylinders are aligned as follows. First, when the variable valve apparatus 10 is first assembled, an adjustment shim 60 having a predetermined reference thickness is used. Then, after the assembly, the control shaft 16 is rotated to a predetermined reference rotational position, and the operating angle of the intake valve 12 is measured for each cylinder in this state. If the operating angle varies among the cylinders as a result of the measurement, the adjustment shim 60 is made thicker for each cylinder according to the amount of deviation between the measured value of each cylinder and a predetermined reference value or design value. Replace with a different one. That is, in the cylinder that is desired to be finely adjusted in the direction of increasing the operating angle, the adjustment shim 60 is replaced with one having a thickness thinner than the reference value. On the contrary, in the cylinder in which it is desired to finely adjust the working angle in the direction of reducing the working angle, the adjustment shim 60 is replaced with one having a thickness larger than the reference value.

  By the way, if the mounting angle of the control member 26 with respect to the control shaft 16 is changed by exchanging the adjustment shim 60, the angles of the contact surfaces of the control pin 48, the adjustment shim 60, and the adjustment pin 50 also change. At this time, in this embodiment, since the adjustment pin 50 is rotatable in the bearing hole 44, the angle change of the contact surface can be absorbed, and the surface contact state of the contact surface is reliably maintained. be able to. For this reason, the attachment angle of the control member 26 with respect to the control shaft 16 can be accurately defined, and the operating angle of the intake valve 12 can be adjusted with high accuracy.

  FIG. 6 shows a state in which the operating angle of the intake valve 12 is large (maximum) (hereinafter referred to as “large operating angle state”) and a small (minimum) operating angle (hereinafter referred to as “minimum”). FIG. As shown in the upper diagram in FIG. 6, in the large working angle state, the working angle adjusting mechanism 37 is positioned to face the lost motion spring 30. In this state, the direction in which the adjustment shim 60 is attached / detached (hereinafter referred to as “the shim attaching / detaching direction”) is directed toward the lost motion spring 30. For this reason, the lost motion spring 30 becomes an obstacle, and the work of detaching the adjustment shim 60 cannot be performed. That is, in the large working angle state, the adjustment work by the working angle adjusting mechanism 37 cannot be performed.

  When the control shaft 16 is rotated clockwise in FIG. 6 from the large operating angle state, the small operating angle state is obtained. As shown in the lower diagram in FIG. 6, in the small working angle state, the working angle adjusting mechanism 37 faces an external space where no components such as the lost motion spring 30 exist. That is, the shim attachment / detachment direction faces the external space. For this reason, the lost motion spring 30 or the like does not become an obstacle, and the tool or the like can easily reach the working angle adjusting mechanism 37, so that the operation of removing the adjustment shim 60 can be easily performed. Thus, the variable valve apparatus 10 can perform the adjustment work by the working angle adjusting mechanism 37 in the small working angle state.

  Incidentally, as described above, the swing arm 18 is urged clockwise in FIG. 6 by the lost motion spring 30. The urging force is transmitted to the control member 26 as follows, and urges the control member 26 in the direction of turning clockwise or counterclockwise in FIG.

  For example, in a certain state, the slider roller 22 is biased so as to move toward the distal end of the swing arm 18 by the biasing force of the lost motion spring 30. This is because the distance between the drive cam 14 and the slider surface 20 becomes wider toward the distal end side of the swing arm 18 and the slider roller 22 tends to escape in that direction. When the slider roller 22 is urged toward the tip of the swing arm 18 in this way, the urging force is transmitted through the intermediate arm 24, and the control member 26 urges clockwise in FIG. Is done.

  Further, in another state where the position of the slider roller 22 (that is, the working angle of the intake valve 12) and the rotational position of the drive cam 14 are different, the control member 26 rotates counterclockwise in FIG. May be energized. Thus, the control member 26 is urged in the clockwise or counterclockwise direction in FIG. 6 by the urging force of the lost motion spring 30.

  When the urging force of the lost motion spring 30 is compared between the large operating angle state and the small operating angle state, the urging force of the lost motion spring 30 is smaller in the small operating angle state for the following reason. Since the distance between the drive cam 14 and the slider surface 20 increases toward the distal end side of the swing arm 18, a large action is obtained in the small operating angle state where the slider roller 22 is positioned on the distal end side of the swing arm 18. Compared with the angular state, the rotational position of the swing arm 18 is a position displaced clockwise in FIG. Therefore, as shown in the lower diagram of FIG. 6, in the small working angle state, the displacement of the arm 31 of the lost motion spring 30 is smaller than the displacement in the large working angle state indicated by the broken line, and the large working angle state. The urging force is smaller than Therefore, the biasing force acting on the control member 26 is also smaller in the small operating angle state than in the large operating angle state.

  When the adjustment operation of the working angle adjustment mechanism 37 is performed, it is preferable that the biasing force acting on the control member 26 is small for the following reason. In the adjustment work, the bolt 62 is loosened and the adjustment shim 60 is replaced. When a clockwise urging force is acting on the control member 26, the urging force acts in a direction to move the adjustment pin 50 away from the control pin 48. Therefore, the pulling force acting on the bolt 62 is a fraction of the urging force. It becomes the state that became larger only. For this reason, since a strong force is required when loosening the bolt 62, it is difficult to work and wear of the bolt 62 also proceeds.

  On the other hand, when a counterclockwise urging force is applied to the control member 26, the urging force is applied in a direction to bring the adjustment pin 50 closer to the control pin 48. Therefore, even after the bolt 62 is loosened, the adjustment shim 60 Is sandwiched between the adjustment pin 50 and the control pin 48 by the biasing force. For this reason, it is difficult to remove and attach the adjustment shim 60. For this reason, if the urging force acting on the control member 26 is strong, the adjustment operation of the working angle adjustment mechanism 37 becomes difficult even if the direction is either clockwise or counterclockwise.

  As described above, the variable valve operating apparatus 10 of the present embodiment is configured to perform the adjustment operation of the operating angle adjusting mechanism 37 in the small operating angle state. In the small operating angle state, as described above, since the urging force of the lost motion spring 30 is relatively small, the urging force acting on the control member 26 is also relatively small. For this reason, the adjustment operation of the working angle adjustment mechanism 37 can be performed relatively easily, and excellent workability can be obtained.

  By the way, in the small working angle state, since the flow rate of the air passing through the intake valve 12 is absolutely small, the in-cylinder air amount changes greatly even if the working angle is slightly different. On the other hand, in the large working angle state, since the flow rate of air passing through the intake valve 12 is absolutely large, the in-cylinder air amount does not change much even if the working angle is slightly different. For this reason, in an internal combustion engine in which the working angle of the intake valve 12 is variable, in order to equalize the air amount of each cylinder, the working angle of the intake valve 12 in the small working angle state is accurately between cylinders. It is important that they are aligned. According to the present embodiment, the adjustment operation of the operating angle adjusting mechanism 37 of each cylinder is performed in the small operating angle state, so that the operating angle of the intake valve 12 of each cylinder accurately matches in the small operating angle state. Will be adjusted. For this reason, the air amount of each cylinder can be made uniform not only in a region where the operating angle of the intake valve 12 is large but also in a region where the operating angle of the intake valve 12 is small. As a result, since the generated torque for each cylinder, the air-fuel ratio for each cylinder, and the like can be accurately aligned, torque fluctuations of the internal combustion engine can be reduced, and emission performance can be improved.

  Further, in the present embodiment, the lost motion spring 30 is constituted by a torsion coil spring and is arranged in a posture in which the central axis thereof is parallel to the control axis 16. When the torsion coil spring is deformed, only the angle of the arm 31 changes, and since there is no expansion / contraction like the compression coil spring, it is not necessary to secure a space for expansion / contraction, and the size of the spring itself is also large. It can be made smaller than the compression coil spring. In the present embodiment, by using such a torsion coil spring as the lost motion spring 30 and arranging it in parallel with the control shaft 16, the variable valve apparatus 10 can be configured more compactly.

  Furthermore, in the present embodiment, as can be seen from FIG. 6, in the large working angle state (first state), the working angle adjusting mechanism 37 enters between the control shaft 16 and the lost motion spring 30 and the small working angle state. In the (second state), the operating angle adjusting mechanism 37 is configured to come out between the control shaft 16 and the lost motion spring 30. As a result, the lost motion spring 30 can be arranged so that the space between the control shaft 16 and the lost motion spring 30 can be effectively utilized, so that the variable valve operating apparatus 10 can be configured extremely compactly. it can. Further, in the small working angle state, the working angle adjusting mechanism 37 comes out between the control shaft 16 and the lost motion spring 30, so that the working operation of the working angle adjusting mechanism 37 can be easily performed.

It is a cross-sectional side view which shows the variable valve apparatus of Embodiment 1 of this invention. It is a perspective view of the variable valve apparatus shown in FIG. It is a perspective view of the variable valve apparatus shown in FIG. It is a perspective view which shows the decomposition | disassembly state of the working angle adjustment mechanism with which the variable valve apparatus shown in FIG. 1 is provided. It is a perspective view which shows the assembly state of the working angle adjustment mechanism with which the variable valve apparatus shown in FIG. 1 is provided. It is the figure which compared the large working angle state and the small working angle state in the variable valve apparatus shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Variable valve apparatus 12 Intake valve 14 Drive cam 16 Control shaft 18 Swing arm 19 Spring receiving part 20 Slider surface 22 Slider roller 24 Intermediate arm 26 Control member 28 Swing cam surface 30 Lost motion spring 31 Arm 32 Rocker arm 34 Rocker Roller 36 Hydraulic lash adjuster 38 Pin insertion hole 40 Control shaft insertion hole 42 Pin insertion hole 44 Bearing hole 46 Bearing hole 48 Control pin 50 Adjustment pin 60 Shim 62 Bolt 64 Nut 66 Bolt insertion hole 68 Screw hole

Claims (7)

A variable valve operating device that varies a working angle of a valve of an internal combustion engine,
A swinging member interposed between the drive cam of the internal combustion engine and the valve, and swinging with the rotation of the drive cam;
A variable mechanism that has a control shaft and changes the swing range of the swing member by rotating the control shaft;
An operating angle adjusting mechanism for finely adjusting the operating angle, which is installed to rotate integrally with the control shaft;
A lost motion spring that biases the swing member toward the drive cam;
With
In the first state where the rotational position of the control shaft is at a position where the urging force of the lost motion spring is maximized, the operating angle adjustment mechanism is opposed to the lost motion spring,
In the second state where the rotational position of the control shaft is at a position where the urging force of the lost motion spring is minimized, the working angle adjustment mechanism can be adjusted to face the external space. A variable valve operating apparatus characterized by being configured.   The variable valve operating apparatus according to claim 1, wherein the lost motion spring is a torsion coil spring. The lost motion spring is composed of a torsion coil spring, and its central axis is arranged in a posture parallel to the control axis,
In the first state, the working angle adjustment mechanism enters between the control shaft and the lost motion spring, and in the second state, the working angle adjustment mechanism moves between the control shaft and the lost motion spring. 2. The variable valve operating apparatus according to claim 1, wherein the variable valve operating apparatus is configured to exit from the space.   4. The variable valve operating apparatus according to claim 1, wherein the first state is a large working angle state, and the second state is a small working angle state. 5. The internal combustion engine has a plurality of cylinders,
The first state is a large working angle state, the second state is a small working angle state,
4. The adjustment according to any one of claims 1 to 3, wherein the working angle adjustment mechanism is adjusted so that the working angles of the valves of the cylinders are aligned in the small working angle state. Variable valve device. The variable mechanism is
A control member that rotates integrally with the control shaft;
An intermediate arm rotatably connected to the control member;
An intermediate member supported at the tip of the intermediate arm and disposed between the drive cam and the swing member;
Including
The working angle adjusting mechanism includes a shim that adjusts the mounting angle of the control member with respect to the control shaft, and finely adjusts the working angle by exchanging the shim with a different thickness. The variable valve operating apparatus according to any one of claims 1 to 5.   7. The acceptable state according to claim 6, wherein in the first state, the attaching / detaching direction of the shim faces the lost motion spring side, and in the second state, the attaching / detaching direction of the shim faces the external space side. Variable valve device.

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