JP4415042B2 - Variable valve operating device for internal combustion engine - Google Patents

Description

  The present invention relates to a variable valve operating apparatus for an internal combustion engine that can control the operation timing and the amount of opening of an intake valve or an exhaust valve in accordance with the operating state of the internal combustion engine.

  In an internal combustion engine such as an automobile, in order to improve fuel efficiency at low speed rotation and output at high speed rotation, the operation timing (valve timing) of the intake valve or exhaust valve (valve timing) and the opening of the intake valve or exhaust valve may be increased depending on the operating state. A variable valve gear that can control the amount (valve lift amount) has been proposed.

  This type of variable valve operating device is swingably supported by a camshaft and can swing an intake valve or an exhaust valve, a drive cam provided on the outer periphery of the camshaft, and a drive cam. A link arm that is rotatably supported, a control cam provided on the outer periphery of the control shaft, a rocker arm that is swingably supported by the control cam, and one end side of which is linked to the link arm, and the other end of the rocker arm A link rod connecting the side and the swing cam, and transmitting the swing of the link arm accompanying the rotation of the camshaft to the swing cam via the rocker arm and the link rod to control the intake valve or the exhaust valve. It is designed to open and close.

  That is, a link mechanism is constituted by the link arm, the rocker arm, the link rod and the swing cam, and the swing cam swings by the rotation of the cam shaft by the link mechanism.

  Further, the rocking angle of the rocking cam is changed by rotating the control shaft by a predetermined angle to deviate the rocking center of the rocker arm from the axis of the camshaft. The operation timing and the opening amount of the intake valve or the exhaust valve are controlled.

  By the way, in the conventional example, a link mechanism is constituted by the link arm, the rocker arm, the link rod and the swing cam, and the swing cam swings by the rotation of the camshaft by this link mechanism. Therefore, there is a possibility that the operation timing and the amount of opening of the intake valve or the exhaust valve vary depending on the dimensional accuracy between the connection points.

  Therefore, if the operating timing and opening amount of the intake valve or exhaust valve are not within the expected range, the entire variable valve operating apparatus must be disassembled and reassembled. In order to adjust within a predetermined range, there exists a possibility that a man-hour may increase.

  The present invention has been devised in view of the above-described conventional situation, and an object of the present invention is to provide a variable valve apparatus capable of easily adjusting the operation timing and the opening amount of an intake valve or an exhaust valve.

Accordingly, the invention described in claim 1 is directed to the drive cam provided on the outer periphery of the camshaft, the swing cam that is swingably supported and can operate the intake valve or the exhaust valve, and the rotation of the drive cam. Accordingly, a transmission mechanism for swinging the swing cam, a control shaft for controlling the lift amount of the intake valve or the exhaust valve by changing the swing angle of the swing cam by controlling the position, and the control shaft After adjusting the lift amount error of the intake valve or exhaust valve by changing the transmission path of the transmission mechanism and the control device for controlling the position of the intake valve or the exhaust valve. And an adjusting means for fixing the lift amount so as not to change.

According to a second aspect of the present invention, there is provided a drive cam provided on the outer periphery of the camshaft, a swing cam that is swingably supported and can operate an intake valve or an exhaust valve, and the rotation of the drive cam. A transmission mechanism for oscillating the oscillating cam; a control shaft for changing the oscillating angle of the oscillating cam by controlling the position to control the operation timing and the opening amount of the intake valve or exhaust valve; and the control A control device that controls the position of the shaft based on the operating state of the internal combustion engine, and a state in which minute errors in the operation timing and the opening amount of the intake valve or the exhaust valve can be adjusted by changing the transmission path of the transmission mechanism And an adjusting means that can be selected in a state in which the operation timing and the opening amount of the intake valve or the exhaust valve are fixed.

  In the first aspect of the invention, a plurality of types of link rods having different dimensions between the connection point where the second connection pin is inserted and the connection point where the third connection pin is inserted are prepared in advance. When the operation timing and the opening amount of the intake valve or the exhaust valve are not within the predetermined range, the second connecting pin and the third connecting pin are removed, and the link rod is replaced with one having a predetermined size.

  As a result, the dimension between the connection point by the second connection pin and the connection point by the third connection pin is adjusted, so that the operation timing and the opening amount of the intake valve or the exhaust valve are adjusted within the expected range. Will be.

  Therefore, it is possible to obtain a variable valve operating apparatus that can easily adjust the operation timing and the opening degree of the intake valve or the exhaust valve.

  In addition, an escape portion is formed at a predetermined position of the link arm or the drive cam to prevent the third connecting pin from interfering when the third connecting pin is attached / detached. Work can be done easily.

In the invention according to claim 2, when the operation timing and the opening amount of the intake valve or the exhaust valve are not within a predetermined range, the connecting portion protruding in the radial direction from the base portion of the link arm is provided. By changing the protruding dimension, the dimension between the center of the drive cam and the connection point to the rocker arm is changed.

  As a result, the dimension between the center of the drive cam in the link arm rotatably supported by the drive cam and the connection point to the rocker arm is adjusted. It is adjusted within the expected range.

  Accordingly, it is possible to obtain a valve operating device that can easily adjust the operation timing and the opening degree of the intake valve or the exhaust valve.

  As described above in detail, according to the present invention, a valve operating device capable of easily adjusting the operation timing and the opening amount of the intake valve or the exhaust valve is obtained.

BEST MODE FOR CARRYING OUT THE INVENTION

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a front view of a variable valve operating apparatus showing an embodiment of the present invention, and FIG. 2 is a side view of FIG. In FIG. 2, except for the bearings, the overlapping of each member is ignored, and the part that is actually hidden by other members is also shown by a solid line.

  In the figure, reference numeral 1 denotes a camshaft. The camshaft 1 is attached to a cylinder head 3 while being supported by a bearing 2. On the outer periphery of the camshaft 1, a drive cam 4 having an axis that is eccentric from the axis of the camshaft 1 is provided.

  A swing cam 5 is swingably supported by the camshaft 1. The swing cam 5 can open and close an intake valve or an exhaust valve (not shown).

  A link arm 6 is rotatably supported by the drive cam 4. The link arm 6 includes a base portion 7 that is rotatably supported by the drive cam 4 and a connecting portion 8 that protrudes in the radial direction from the base portion 7.

  Reference numeral 9 denotes a control shaft arranged substantially parallel to the camshaft 1, and a control cam 10 having an axis eccentric from the axis of the control shaft 9 is provided on the outer periphery of the control shaft 9. .

  Reference numeral 11 denotes a rocker arm supported on the control cam 10 so as to be swingable. One end side of the rocker arm 11 is connected to the connecting portion 8 of the link arm 6, and the other end side is connected to the swing cam 5 via the link rod 12. That is, the link rod 12 connects the other end of the rocker arm 11 and the swing cam 5.

  The connecting portion 8 of the link arm 6 and one end side of the rocker arm 11 are connected by a first connecting pin 15, and the other end side of the rocker arm 11 and one end side of the link rod 12 are connected by a second connecting pin 16, The other end side of the link rod 12 and the swing cam 5 are connected by a third connecting pin 17.

  Specifically, the first connecting pin 15 is inserted into a through hole 18 formed in the connecting portion 8 of the link arm 6 and a through hole 19 formed on one end side of the rocker arm 11. The second connecting pin 16 is inserted into a through hole 21 formed on the other end side of the rocker arm 11 and a through hole 22 formed on one end side of the link rod 12, and retaining rings 23 provided at both ends thereof. The removal is prevented. The third connecting pin 17 is inserted into a through hole 24 formed on the other end side of the link rod 12 and a through hole 25 formed on the swing cam 5, and by retaining rings 26 provided at both ends thereof. Removal is prevented.

  Reference numeral 29 denotes an escape portion formed on the outer peripheral side of the base portion 7 of the link arm 6. The escape portion 29 is formed at a position that prevents the third connecting pin 17 from interfering with the third connecting pin 17 when the third connecting pin 17 is attached and detached at the maximum lift in a state where the variable valve device is assembled. That is, since the third connecting pin 17 is disposed at a position relatively close to the axial center of the camshaft 1, it can be attached and detached by interfering with the drive cam 4 and the link arm 6 when the variable valve gear is assembled. However, since the escape portion 29 is formed at the position of the link arm 6, the third connecting pin 17 can be easily attached and detached when the variable valve device is assembled. The force acting on the portion 29 is minimized. In addition, since the maximum lift position has the maximum influence of error, it is optimal as a measurement position, and the work life is improved by measuring at the replacement position.

  Since the second connecting pin 16 is disposed at a position relatively distant from the axis of the camshaft 1 and the axis of the control shaft 9, it can be easily attached and detached.

  The variable valve operating apparatus having such a configuration transmits the swing of the link arm 6 accompanying the rotation of the camshaft 1 to the swing cam 5 via the rocker arm 11 and the link rod 12, and an intake valve (not shown). Or open and close the exhaust valve.

  That is, a link mechanism is constituted by the link arm 6, the rocker arm 11, the link rod 12 and the swing cam 5, and the swing cam 5 swings by the rotation of the camshaft 1 by this link mechanism. Become.

  Further, by rotating the control shaft 9 by a predetermined angle to deviate the rocking center of the rocker arm 11 with respect to the axis of the camshaft 1, the rocking angle of the rocking cam 5 is changed. The operation timing and the amount of opening of the external intake valve or exhaust valve are controlled. The rotation of the control shaft 9 can be controlled by a control device (not shown) to which the operating state of the internal combustion engine is input.

  Here, in the initial stage of assembly of the variable valve operating device, etc., when the operation timing and opening degree of the intake valve or exhaust valve (not shown) are not within the predetermined range, the connection point where the second connection pin 16 is inserted. And preparing a plurality of types of link rods 12 having different dimensions (l) between the connecting point where the third connecting pin 17 is inserted and removing the second connecting pin 16 and the third connecting pin 17, Replace the link rod 12 with one of a predetermined size.

  In this case, one or both of the retaining rings 23 provided at both ends of the second connecting pin 16 are removed, and the second connecting pin 16 is removed. Further, one or both of the retaining rings 26 provided on both ends of the third connecting pin 17 are removed, and the third connecting pin 17 is removed. After the link rod 12 is replaced with one having a predetermined size, the second connecting pin 16 and the retaining ring 23 and the third connecting pin and retaining ring 26 are attached again.

  As a result, the dimension (l) between the connection point by the second connection pin 16 and the connection point by the third connection pin 17 is adjusted. It will be adjusted within the expected range.

  Therefore, it is possible to obtain a variable valve operating apparatus that can easily adjust the operation timing and the opening degree of the intake valve or the exhaust valve.

  In addition, an escape portion 29 is formed at a predetermined position of the link arm 6 to prevent the third connecting pin 17 from interfering with the third connecting pin 17 when the third connecting pin 17 is attached or detached. Can be easily attached and detached.

  3 to 9 are drawings showing other embodiments of the present invention. Hereinafter, these embodiments will be described in order. In the description, the same components as those in the above-described embodiment are denoted by the same reference numerals, and redundant description thereof is omitted.

  First, in the embodiment shown in FIG. 3, an escape portion 30 that prevents the third connecting pin 17 from interfering is formed in the drive cam 4 in place of the escape portion 29 of the above embodiment.

  That is, when the drive cam 4 provided on the outer periphery of the camshaft 1 is at the minimum lift, an escape portion 30 is formed through the drive cam 4 at a position where the third connecting pin 17 faces. The escape portion 30 is formed in an arc shape with the axis of the camshaft 1 as the center.

  In such a configuration, the escape portion 30 provided in the drive cam 4 allows the third connecting pin 17 to be easily attached and detached while being attached to the cylinder head when the variable valve device is assembled. The rod 12 can be easily replaced with a rod having a predetermined dimension, and the dimension (l) between the connection points of the second connection pin 16 and the third connection pin 17 is easily adjusted.

  Therefore, also in this embodiment, a variable valve operating apparatus capable of easily adjusting the operation timing and the opening degree of the intake valve or the exhaust valve is obtained as in the above embodiment.

  In addition, an escape portion 30 is formed at a predetermined position of the drive cam 4 so as to prevent the third linkage pin 17 from interfering when the third linkage pin 17 is attached and detached. Can be easily attached and detached.

  Next, in the embodiment shown in FIGS. 5 to 7, the second connecting pin 16 that connects the rocker arm 11 and the link rod 12 is configured to have an eccentric shaft, and the second connecting pin 16 is rotated by a predetermined angle. In addition, by changing the dimension between the connection points, it is possible to adjust the operation timing and the opening degree of the intake valve or the exhaust valve (not shown).

  In other words, the second connecting pin 16 that connects the rocker arm 11 (the other end side) and the link rod 12 (the one end side) is eccentric shaft 33 that is eccentric from the axial center on both ends at the substantially central portion in the axial direction. The eccentric shaft 33 is inserted into the through hole 22 formed in the link rod 12, and both end sides of the eccentric shaft 33 are inserted into the through hole 21 formed in the rocker arm 11.

  A radial flange 34 is formed at one end of the second connecting pin 16, and a through hole 35 is formed in the flange 34. The through hole 35 is formed in an arc shape with the axis of the second connecting pin 16 as the center. A bolt 36 can be inserted into the through hole 35 of the flange 34, and the bolt 36 is screwed into the rocker arm 6. Thereby, the flange 34 can be fixed to one member to which the connecting pin 16 is connected, that is, the rocker arm 6.

  In such a configuration, when the operation timing and opening degree of the intake valve or exhaust valve (not shown) driven by the swing cam 5 are not within the predetermined range, the second shaft having the eccentric shaft 33 is provided. The connecting pin 16 is rotated by a predetermined angle to change the dimension between the connecting points. In this case, the rotation of the second connecting pin 16 is performed within the range in which the arc-shaped through hole 35 is formed by loosening the bolt 36. After the second connecting pin 16 is rotated by a predetermined angle, the bolt 36 is tightened to fix the flange 34 to the rocker arm 11 again.

  As a result, the dimension between the connecting point by the second connecting pin 16 provided with the eccentric shaft 33 and the connecting point by another connecting pin is adjusted. The amount will be adjusted within the expected range.

  Therefore, also in this embodiment, a valve operating device capable of easily adjusting the operation timing and the opening degree of the intake valve or the exhaust valve is obtained.

  In addition, a radial flange 34 is formed on one end side of the second connecting pin 16 having the eccentric shaft 33, and this flange 34 is connected to one member to which the second connecting pin 16 is connected, that is, the rocker arm 11. Since the second connecting pin 16 is prevented from being inadvertently rotated, the dimensions between the connecting points can be stably obtained.

  Although the embodiment in which the eccentric shaft 33 is provided on the second connecting pin 16 has been described, the first connecting pin 15 and / or the third connecting pin 17 may be provided with an eccentric shaft.

  Next, in the embodiment shown in FIGS. 8 and 9, the connecting portion 8 of the link arm 6 can be expanded and contracted in the radial direction from the base portion 7, and the protruding dimension of the connecting portion 8 in the radial direction is changed. The operation timing and opening degree of the intake valve or exhaust valve (not shown) can be adjusted.

  That is, the link arm 6 includes a base portion 7 that is rotatably supported by the drive cam 4 and a connecting portion 8 that protrudes radially from the base portion 7 and is connected to the rocker arm 11. The connecting portion 8 is a base portion. 7 protrudes in a radial direction so as to be expandable and contractible.

  Specifically, the connecting portion 8 of the link arm 6 is connected to the base portion 7 via a screw portion 36. That is, the connecting portion 8 is screwed and fixed to the base portion 7, and a through hole 18 through which the first connecting pin 15 for connecting to the rocker arm 11 is inserted is formed in the connecting portion 8. Reference numeral 37 denotes a lock nut that is screwed into the screw portion 36 of the connecting portion 8 to prevent the connecting portion 8 from loosening.

  In such a configuration, when the operation timing and the opening amount of the intake valve or exhaust valve (not shown) driven by the rocking cam 5 are not within the predetermined range, radiation from the base portion 7 of the link arm 6 is performed. The projecting dimension of the connecting portion 8 projecting in the direction is changed, and the dimension (m) between the center of the drive cam 4 and the connecting point to the rocker arm 11 is changed. In this case, the connecting portion 8 is moved in the radial direction by loosening the lock nut 37 and changing the screwing amount to the base portion 7. After moving the connecting portion 8, the connecting portion 8 is fixed again by the lock nut 37.

  As a result, the dimension (m) between the center of the drive cam 4 and the connecting point to the rocker arm 11 in the link arm 6 rotatably supported by the drive cam 4 is adjusted. Alternatively, the operation timing and the opening amount of the exhaust valve are adjusted within the expected range.

  Therefore, also in this embodiment, a valve operating device capable of easily adjusting the operation timing and the opening degree of the intake valve or the exhaust valve is obtained.

  In addition, the base portion 7 and the connecting portion 8 of the link arm 6 are connected via a screw portion 36, and a lock nut 37 is attached to the screw portion 36, so the 36 pitch of the screw portion is reduced. As a result, fine adjustment is possible, and the lock nut 37 prevents inadvertent expansion and contraction of the connecting portion 8, thereby stabilizing the dimension between the center of the drive cam 4 and the connecting point to the rocker arm 11. Can be obtained.

  Although the embodiment has been described with reference to the drawings, the specific configuration is not limited to this embodiment and can be changed without departing from the gist of the invention.

It is a front view of the variable valve apparatus which shows embodiment of this invention. It is a side view of FIG. It is drawing similar to FIG. 2 which shows another embodiment of this invention. It is a front view of the variable valve apparatus which shows another embodiment of this invention. FIG. 5 is a side view of FIG. 4. It is drawing which expands and shows the principal part of FIG. It is the sectional view on the AA line of FIG. It is drawing similar to FIG. 2 which shows another embodiment of this invention. It is a front view which shows the link arm shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cam shaft 4 Drive cam 5 Oscillating cam 6 Link arm 9 Control shaft 10 Control cam 11 Rocker arm 12 Link rod 15 1st connection pin 16 2nd connection pin 17 3rd connection pin

Claims (2)

A drive cam provided on the outer periphery of the camshaft;
A swing cam that is swingably supported and can operate an intake valve or an exhaust valve;
A transmission mechanism that swings the swing cam as the drive cam rotates;
A control shaft for controlling the lift amount of the intake valve or the exhaust valve by changing the swing angle of the swing cam by controlling the position;
A control device for controlling the position of the control shaft based on the operating state of the internal combustion engine;
Adjusting means for adjusting the lift amount of the intake valve or the exhaust valve after changing the lift amount of the intake valve or the exhaust valve by changing the transmission path of the transmission mechanism; and
A variable valve operating apparatus for an internal combustion engine, comprising: A drive cam provided on the outer periphery of the camshaft;
A swing cam that is swingably supported and can operate an intake valve or an exhaust valve;
A transmission mechanism that swings the swing cam as the drive cam rotates;
A control shaft for controlling the operation timing and the opening amount of the intake valve or the exhaust valve by changing the swing angle of the swing cam by controlling the position;
A control device for controlling the position of the control shaft based on the operating state of the internal combustion engine;
A state in which minute errors in the intake valve or exhaust valve operation timing and opening amount can be adjusted by changing the transmission path of the transmission mechanism, and an operation timing and opening amount of the intake valve or exhaust valve are fixed. Adjustment means selectable to, and
A variable valve operating apparatus for an internal combustion engine, comprising:

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