JP6775402B2 - Variable valve mechanism of internal combustion engine - Google Patents

Description

The present invention relates to a variable valve mechanism that drives a valve of an internal combustion engine and changes the driving state of the valve according to an operating condition of the internal combustion engine.

The variable valve mechanism 90 of the conventional example (Patent Document 1) shown in FIG. 18A has a first arm 91 driven by the first cam and swings, and a valve driven by the second cam and swings. A second arm 92 for driving the 85 and a third arm 93 driven by the third cam to swing are provided. Then, by connecting only the first arm 91 of the first and third arms 91 and 93 to the second arm 92, it is switched to the first state in which the valve 85 is driven by the first cam, and only the third arm 93 is switched. By connecting to the second arm 92, it switches to the third state in which the valve 85 is driven by the third cam, and by not connecting to the second arm 92, it switches to the second state in which the valve 85 is driven by the second cam. Switch.

FIG. 18B shows the first curve C1 showing the valve lift amount with respect to the rotation angle of the internal combustion engine in the first state, the second curve C2 showing the same value in the second state, and the same value in the third state. The third curve C3 showing the above is shown.

Japanese Unexamined Patent Publication No. 2014-101814

Recently, due to the need for higher output and lower fuel consumption, each curve C1, C2, C3 is required to have a high degree of design freedom, for example, the first, second and third curves C1, C2 and C3 can intersect each other. ing.

In that respect, in the conventional example, since the second arm 92 is separated from the third arm 93 in the first state and the first arm 91 is separated from the second arm 92 in the third state, the first curve C1 and the third curve C3 are separated. Can be crossed with. However, since the second curve C2 cannot exceed either the first curve C1 or the third curve C3, it must be designed so as to fit within the region ro indicated by the hatching of the two-point diagonal line in FIG. 18 (b). It doesn't become. Therefore, the first curve C1 can intersect the third curve C3, but cannot intersect the second curve C2.

In addition, the state at the time of starting the internal combustion engine is to be freely selected from the first, second and third states according to the properties of the internal combustion engine, but the hydraulic pressure is only low pressure (hydraulic pressure OFF) at the time of starting. In addition, due to the structure of the arm and the like, it is difficult to freely select the option.

Therefore, the first purpose is to allow the first curve to intersect with both the second and third curves, and the state at the time of starting the internal combustion engine can be freely selected from the first, second and third states. The second purpose is to be able to select.

In order to achieve the first object, the variable valve mechanism of the present invention is configured as follows. The variable valve mechanism includes a first input arm that is driven by the first cam and swings, a second input arm that is driven by the second cam and swings, and a third that is driven by the third cam and swings. An input arm, an output arm that drives a valve when swinging, an alternative device that selectively connects either the first input arm or the second input arm to the output arm, and a third to the second input arm. It includes a switching device for switching between a state in which the input arm is not connected and a state in which the input arm is connected.

The variable valve mechanism is in the first state when the first input arm is connected to the output arm, and is second unless the second input arm is connected to the output arm and the third input arm is connected to the second input arm. When the second input arm is connected to the output arm and the third input arm is connected to the second input arm, the third state is reached.

The second curve showing the valve lift amount with respect to the rotation angle of the internal combustion engine in the second state falls within the region below the third curve showing the valve lift amount with respect to the rotation angle of the internal combustion engine in the third state. The first curve, which indicates the valve lift amount with respect to the rotation angle of the internal combustion engine in the first state, intersects both the second curve and the third curve.

The state at the time of starting the internal combustion engine is not particularly limited, but in order to achieve the second object, it is preferable to be any of the following aspects [1] to [3].
[1] The alternative device is provided with an alternative hydraulic chamber, and connects the first input arm to the output arm when the hydraulic pressure in the alternative hydraulic chamber becomes a relatively low low pressure, and outputs when the hydraulic pressure becomes relatively high. It is configured to connect the second input arm to the arm. When the internal combustion engine is started, the hydraulic pressure in the alternative hydraulic chamber becomes low, which is the first state. In addition, this embodiment includes modification 2, Example 2, and Example 3 of Example 1.

[2] The alternative device is provided with an alternative hydraulic chamber, and connects the second input arm to the output arm when the hydraulic pressure in the alternative hydraulic chamber becomes a relatively low low pressure, and outputs when the hydraulic pressure becomes relatively high. It is configured to connect the first input arm to the arm. The switching device is provided with a switching hydraulic chamber. When the hydraulic pressure in the switching hydraulic chamber becomes a relatively low low pressure, the third input arm is not connected to the second input arm, and when the hydraulic pressure becomes relatively high, the second input arm It is configured to connect the third input arm to. When the internal combustion engine is started, the hydraulic pressure in the alternative hydraulic chamber becomes low and the hydraulic pressure in the switching hydraulic chamber becomes low, so that the second state is reached. In addition, this embodiment includes the first modification of the first embodiment, the first modification of the second embodiment, and the first modification of the third embodiment.

[3] The alternative device is provided with an alternative hydraulic chamber, and connects the second input arm to the output arm when the hydraulic pressure in the alternative hydraulic chamber becomes a relatively low low pressure, and outputs when the hydraulic pressure becomes relatively high. It is configured to connect the first input arm to the arm. The switching device is provided with a switching hydraulic chamber, and the third input arm is connected to the second input arm when the hydraulic pressure in the switching hydraulic chamber becomes a relatively low low pressure, and the connection is not performed when the hydraulic pressure in the switching hydraulic chamber becomes a relatively high high pressure. It is configured in. When the internal combustion engine is started, the hydraulic pressure in the alternative hydraulic chamber becomes low and the hydraulic pressure in the switching hydraulic chamber becomes low, so that the third state is reached. In addition, this aspect includes the modification 1 of the embodiment 1, the modification 2 of the embodiment 2, and the modification 2 of the embodiment 3.

According to the present invention, the second and third input arms are separated from the output arm in the first state, and the first input arm is separated from the output arm in the second and third states. It will be possible to intersect both the curve and the third curve. Therefore, the degree of freedom in designing each curve is improved, and the optimum design is possible, which contributes to reduction of fuel consumption and improvement of output. Further, by selecting the aspect [1] above, the state at the time of starting the internal combustion engine can be set to the first state, and by selecting the aspect [2] above, the state at the time of starting can be set to the second state. By selecting the aspect of [3] above, the state at the time of starting can be changed to the third state. Therefore, the state at the time of starting the internal combustion engine can be freely selected from the first, second and third states according to the properties of the internal combustion engine and the like.

It is a perspective view which shows the variable valve mechanism of Example 1. FIG. It is a side view (second state) which shows the variable valve mechanism. It is sectional drawing of the line III-III of FIG. (A) is a cross-sectional view showing the first state of the variable valve mechanism, (b) is a cross-sectional view of the IVb-IVb line of FIG. 2, and (c) is a cross-sectional view showing the third state of the variable valve mechanism. Is. It is a graph which shows the 1st, 2nd and 3rd curves of the variable valve mechanism. (a) is a cross-sectional view showing a modified example 1 of the first embodiment, and (b) is a sectional view showing a modified example 2 of the first embodiment. It is a perspective view which shows the variable valve mechanism of Example 2. FIG. It is a side view which shows the variable valve mechanism (first state). (A) is a cross-sectional view of the line IXa-IXa of FIG. 8, (b) is a cross-sectional view showing the second state of the variable valve mechanism, and (c) is a cross-sectional view showing the third state. (a) is a cross-sectional view showing a modified example 1 of the second embodiment, and (b) is a sectional view showing a modified example 2. It is a perspective view which shows the variable valve mechanism of Example 3. FIG. It is a side view which shows the variable valve mechanism (first state). (A) is a cross-sectional view of the line XIIIa-XIIIa of FIG. 12, and (b) is a cross-sectional view of the line XIIIb-XIIIb of FIG. It is sectional drawing of the XIV-XIV line of FIG. (a) is a cross-sectional view showing the second state of the variable valve mechanism, and (b) is a cross-sectional view showing the third state. (a) is a cross-sectional view showing a modified example 1 of the third embodiment, and (b) is a sectional view showing a modified example 2. (a) is a cross-sectional view showing the second state of the variable valve mechanism of Example 4, and (b) is a cross-sectional view showing the first state. (a) is a perspective view showing a conventional variable valve mechanism, and (b) is a graph showing the first, second and third curves of the variable valve mechanism.

The mode of the alternative device is not particularly limited, and may include, for example, three pins, but it is preferably configured as follows in that the output arm is compactly organized. The alternative device consists of a first alternative pin that is detachably attached to the output arm side of the first input arm and an end face of the first alternative pin that is detachably attached to the second input arm and is attached to the output arm side. The second alternative pin and the alternative pin that are in contact with each other are straddled between the output arm and the first input arm, and the contact portion between the output arm and the second alternative pin is the output arm and the second alternative pin. The first position that comes between the input arm and the second alternative pin straddle between the output arm and the second input arm, and the contact part between the two alternative pins is the output arm and the first input. It is configured to include an alternative displacement device that displaces to a second position that comes between the arm.

The mode of the switching device is not particularly limited, but the following modes will be exemplified. The switching device has a switching pin that is displaceably provided at a connecting position that straddles the second input arm and the third input arm and a non-connecting position that does not straddle the second input arm, and a switching pin as a connecting position. It is configured to include a switching displacement device that displaces the unconnected position.

Each input arm may be in sliding contact with the corresponding cam, but is preferably configured as follows in terms of reducing friction. The first input arm includes a first roller that contacts the first cam. The second input arm includes a second roller that contacts the second cam. The third input arm includes a third roller that contacts the third cam.

The position of each pin is not particularly limited, but the following aspects will be exemplified.
[A] When viewed in the state of the base circle, the alternative pin and the switching pin are provided in a straight line on the center lines of the first, second and third rollers. In addition, this embodiment includes Example 1 and Examples 1 and 2 thereof.
[B] When viewed in the state of the base circle, the alternative pin and the switching pin are provided in a straight line at a position different from the center line of the first, second or third roller. In addition, this embodiment includes Example 2 and Examples 1 and 2 thereof.
[C] When viewed in the state of the base circle, the alternative pins are provided in a straight line on the center lines of the first and second rollers, and the switching pins are provided at positions different from those on the center lines. In addition, this embodiment includes Example 3 and Examples 1 and 2 thereof.

The above aspect [A] is difficult or troublesome to carry out in the above aspect [1] because it is necessary to draw a hydraulic path to the inside of the roller, but the four arms are compactly organized. On the other hand, in the above-described aspects [B] and [C], the entire four arms are larger than those in the above-mentioned aspect [A], but any of the above-mentioned aspects [1], [2], and [3] can be easily implemented.

The specific aspects of the above [A] and [B] are not particularly limited, but the following aspects will be exemplified.
[I] The alternative displacement device has an alternative hydraulic chamber that presses both alternative pins in one direction in the length direction of the straight line with hydraulic pressure in the room and elastic in the other direction in the length direction of the straight line. It is configured to include a spring that urges the switching pin with a force and urges the switching pin in one direction in the length direction of the straight line. The switching displacement device includes the spring and a switching hydraulic chamber that presses the switching pin against the other in the length direction of the straight line by hydraulic pressure in the room. In addition, this embodiment includes Example 1, a modified example 1 thereof, and modified examples 1 and 2 of the second embodiment.

[Ii] The alternative displacement device is a spring that urges the alternative pin to one side in the length direction of the straight line by an elastic force, and the alternative pin is pressed against the other side in the length direction of the straight line by hydraulic pressure in the room. It is configured to include an alternative hydraulic chamber that presses the switching pin in one direction in the length direction of the straight line. The switching displacement device includes the alternative hydraulic chamber and the switching hydraulic chamber that presses the switching pin against the other in the length direction of the straight line by the hydraulic pressure in the chamber. In addition, this embodiment includes modification 2 and embodiment 2 of Example 1.

The specific aspect of the above [C] is not particularly limited, but the following aspects will be exemplified. The alternative displacement device includes an alternative spring that elastically urges the alternative pin in one direction in the length direction of the straight line, and the alternative pin is pressed against the other in the length direction of the straight line by hydraulic pressure in the room. It is configured to include an alternative hydraulic chamber. The switching displacement device includes a switching spring that urges the switching pin to one side in the length direction by an elastic force, and a switching hydraulic chamber that presses the switching pin to the other side in the length direction by hydraulic pressure in the room. ing. In addition, this embodiment includes Example 3 and Examples 1 and 2 thereof.

The intersection of the first curve and the second and third curves is not particularly limited, but exemplifies the following aspects.
[A] The maximum value of the valve lift amount is higher in the first curve than in either the second curve or the third curve, and the working angle is higher in the first curve than in either the second curve or the third curve. Is also narrow.
[B] The maximum value of the valve lift amount is lower in the first curve than in both the second curve and the third curve, and the working angle is lower in the first curve than in either the second curve or the third curve. Is also wide.
[C] The timing of opening the valve is earlier in the first curve than in the second curve and the third curve, and the timing of closing the valve is also earlier in the first curve than in either the second curve or the third curve. Is also early.
[D] The timing of opening the valve is later on the first curve than on either the second curve or the third curve, and the timing of closing the valve is also on the first curve than on either the second curve or the third curve. Is also slow.
The working angle refers to the angle at which the internal combustion engine rotates from the start of opening the valve to the closing of the valve.

Next, examples of the present invention will be shown. However, the present invention is not limited to the examples, and the configuration and shape of each part may be arbitrarily changed and implemented without departing from the spirit of the invention.

As shown in FIG. 1, the variable valve mechanism 1 of the first embodiment is installed with respect to two valves 85 included in the internal combustion engine. The two valves 85 may be intake valves or exhaust valves. The variable valve mechanism 1 includes a camshaft 9, three cams 9a, 9b, 9c formed on the camshaft 9, a rocker shaft 50, and four arms 10 swingably supported by the rocker shaft 50. , 40, 20, 30 and so on. In the following, for convenience, one of the camshafts 9 in the length direction is referred to as "left" and the other in the length direction is referred to as "right", but the left and right may be reversed.

The camshaft 9 rotates according to the rotation of the internal combustion engine, and specifically, the camshaft 9 rotates once every two rotations of the internal combustion engine. The three cams 9a, 9b, 9c are composed of the rightmost first cam 9a, the second cam 9b to the left of the first cam 9a, and the third cam 9c to the left of the first cam 9a. The rocker shaft 50 is a tubular shaft. An oil supply pipe 56 for supplying oil is installed inside the rocker shaft 50.

The four arms 10, 40, 20, and 30 are the rightmost first input arm 10, the output arm 40 to the left of the first input arm 10, the second input arm 20 to the left of the first input arm 10, and the third input to the left of the first input arm 10. It consists of an arm 30. The first input arm 10 is driven by the first cam 9a and swings. The first input arm 10 is provided with a first protrusion 18. The first lost motion spring 19 for urging the first input arm 10 to the first cam 9a is in contact with the first protrusion 18. The second input arm 20 is driven by the second cam 9b and swings. The second input arm 20 is provided with a second protrusion 28. A second lost motion spring 29 for urging the second input arm 20 to the second cam 9b is in contact with the second protrusion 28. The third input arm 30 is driven by the third cam 9c and swings. The third input arm 30 is provided with a third protrusion 38. A third lost motion spring 39 for urging the third input arm 30 to the third cam 9c is in contact with the third protrusion 38. The output arm 40 includes a tip portion 48 extending in the left-right directions L and R. The tip 48 is in contact with the two left and right valves 85. The output arm 40 drives the two left and right valves 85 when swinging. A valve spring (not shown) that urges the valve 85 in the closing direction is attached to each valve 85.

In the following, the base circle of the first cam 9a acts on the first input arm 10, the base circle of the second cam 9b acts on the second input arm 20, and the base circle of the third cam 9c acts on the third input. The time when it acts on the arm 30 is called "base circle time".

As shown in FIG. 2, each cam 9a, 9b, 9c has a base circle having a circular cross-sectional shape and a nose protruding from the base circle. The profiles of the cams 9a, 9b, 9c are different from each other.

As shown in FIG. 3, a first roller 11 that abuts on the first cam 9a is rotatably attached to the first input arm 10 via the first shaft 13 and the bearing 12. The first shaft 13 is a bottomed tubular shaft that opens to the left L. The output arm 40 is provided with connecting holes 46 opened in L and R on both the left and right sides. A second roller 21 that comes into contact with the second cam 9b is rotatably attached to the second input arm 20 via the second shaft 23 and the bearing 22. The second shaft 23 is a tubular shaft and is open to both left and right L and R. A third roller 31 that comes into contact with the third cam 9c is rotatably attached to the third input arm 30 via the third shaft 33 and the bearing 32. The third shaft 33 is a bottomed tubular shaft that opens to the right R. The center lines of the first, second and third shafts 33 and the connecting holes 46 are aligned in the base circle.

The variable valve mechanism 1 is further configured to include an alternative device 60 and a switching device 70.
The alternative device 60 selectively connects either the first input arm 10 or the second input arm 20 to the output arm 40. The alternative device 60 includes a first alternative pin 61, a second alternative pin 62, and an alternative displacement device 65.

The first alternative pin 61 is displaceably installed in the first shaft 13 in the left-right directions L and R. The left portion of the first-choice pin 61 can protrude into the connecting hole 46. The second alternative pin 62 is displaceably installed in the right portion of the second shaft 23 in the left-right directions L and R. The right portion of the second alternative pin 62 can protrude into the connecting hole 46. The end faces of the alternative pins 61 and 62 are in contact with each other.

The alternative displacement device 65 is a device that displaces the alternative pins 61 and 62 in the left-right directions L and R, and includes an alternative hydraulic chamber 66 and a spring S. The alternative hydraulic chamber 66 is provided in the first shaft 13 between its inner bottom and the first alternative pin 61. Oil is supplied from the alternative oil passage 67 into the alternative hydraulic chamber 66. The alternative oil passage 67 extends through the oil supply pipe 56 and the first input arm 10 to the alternative hydraulic chamber 66. The left and right intermediate portions of the oil supply pipe 56 are partitioned by a partition member 57, and the portion on the right side of the partition member 57 constitutes a part of the alternative oil passage 67. The alternative hydraulic chamber 66 presses the alternative pins 61 and 62 to the left L with the hydraulic pressure in the chamber. The spring S is installed in the second shaft 23, and urges the alternative pins 61 and 62 to the right R.

The switching device 70 switches between a state in which the third input arm 30 is not connected to the second input arm 20 and a state in which the third input arm 30 is connected. The switching device 70 includes an intervening pin 72, a switching pin 73, and a switching displacement device 75.

The intervening pin 72 is displaceably installed in the left portion of the second shaft 23 in the left-right directions L and R. The switching pin 73 is displaceably installed in the third shaft 33 in the left-right directions L and R. The right portion of the switching pin 73 can protrude into the second shaft 23. The end faces of the intervening pin 72 and the switching pin 73 are in contact with each other.

The switching displacement device 75 is a device that displaces the intervening pin 72 and the switching pin 73 in the left-right directions L and R, and includes the spring S and the switching hydraulic chamber 76. The spring S is installed between the second alternative pin 62 and the intervening pin 72, and the intervening pin 72 and the switching pin 73 are pressed by a reaction force that urges both alternative pins 61 and 62 to the right R. Elevate to the left L. The switching hydraulic chamber 76 is provided between the bottom surface of the third shaft 33 and the switching pin 73. Oil is supplied from the switching oil passage 77 into the switching hydraulic chamber 76. The switching oil passage 77 extends through the oil supply pipe 56 and the third input arm 30 to the switching hydraulic chamber 76. The portion of the oil supply pipe 56 on the left side of the partition member 57 constitutes a part of the switching oil passage 77. The switching hydraulic chamber 76 presses the switching pin 73 and the intervening pin 72 to the right R with the hydraulic pressure in the chamber.

Next, the function will be described.
As shown in FIG. 4A, when the hydraulic pressure of the alternative hydraulic chamber 66 becomes high pressure (hydraulic pressure ON) and the hydraulic pressure of the switching hydraulic chamber 76 becomes low pressure (hydraulic pressure OFF), the alternative hydraulic pressure chamber 66 becomes The alternative pins 61 and 62 and the intervening pin 72 and the switching pin 73 are hydraulically pressed to the left L. As a result, the alternative pins 61 and 62 are arranged at the first position and the switching pin 73 is arranged at the non-connected position. In the first position, the left part of the first alternative pin 61 straddles between the output arm 40 and the first input arm 10, and the contact portion between the alternative pins 61 and 62 is the output arm 40 and the second input. It is a position where it comes between the arm 20 and the arm 20. The non-connected position is a position where the switching pin 73 does not straddle between the third input arm 30 and the second input arm 20.

Then, by arranging the alternative pins 61 and 62 at the first position, the first input arm 10 is connected to the output arm 40, and the first state is set. The first state is a state in which the first cam 9a drives the valve 85 via the first input arm 10 and the output arm 40. At this time, the third input arm 30 is not connected to the second input arm 20, but even if it is connected, it will still be in the first state. At this time, both the second input arm 20 and the third input arm 30 swing idle.

As shown in FIG. 4B, when the hydraulic pressure of the alternative hydraulic chamber 66 becomes low and the hydraulic pressure of the switching hydraulic chamber 76 becomes low, the elastic force of the spring S causes the alternative pins 61 and 62 to move to the right. By being urged by the direction R and the intervening pin 72 and the switching pin 73 being urged to the left L by the reaction force, the alternative pins 61 and 62 are arranged in the second position and the switching pin 73. Is placed in the unconnected position. In the second position, the right part of the second alternative pin 62 straddles between the output arm 40 and the second input arm 20, and the contact portion between the alternative pins 61 and 62 is the output arm 40 and the first input. It is a position where it comes between the arm 10 and the arm 10. The amount of displacement when shifting from the first position to the second position is substantially the same as the width of the output arm 40 (the length of the connecting hole 46).

As a result, the second input arm 20 is connected to the output arm 40, and the third input arm 30 is not connected to the second input arm 20, resulting in a second state. The second state is a state in which the second cam 9b drives the valve 85 via the second input arm 20 and the output arm 40. At this time, the first input arm 10 and the third input arm 30 are missed.

As shown in FIG. 4C, when the hydraulic pressure of the alternative hydraulic chamber 66 becomes low pressure and the hydraulic pressure of the switching hydraulic chamber 76 becomes high pressure, the hydraulic pressure of the switching hydraulic chamber 76 becomes the alternative pins 61 and 62. Further, the intervening pin 72 and the switching pin 73 are pressed to the right R. As a result, the alternative pins 61 and 62 are arranged at the second position and the switching pin 73 is arranged at the connecting position. The connecting position is a position where the switching pin 73 straddles between the third input arm 30 and the second input arm 20.

As a result, the second input arm 20 is connected to the output arm 40, and the third input arm 30 is connected to the second input arm 20 to enter the third state. The third state is a state in which the third cam 9c drives the valve 85 via the third input arm 30, the second input arm 20, and the output arm 40. At this time, the first input arm 10 swings idle.

FIG. 5 shows a first curve C1 showing the valve lift amount with respect to the rotation angle of the internal combustion engine in the first state, a second curve C2 showing the same value in the second state, and a third curve showing the same value in the third state. The three curves C3 are shown. The second curve C2 fits in the region r below the third curve C3. The maximum value of the valve lift amount is higher in the first curve C1 than in both the second curve C2 and the third curve C3, and the working angle of the first curve C1 is higher in the second curve C2 and the third curve C3. Narrower than any of. The timing of opening the valve is substantially the same for the first, second and third curves C1, C2 and C3, and the closing timing of the first curve C1 is higher than that of the second curve C2 and the third curve C3. early. Therefore, the first curve C1 intersects both the second curve C2 and the third curve C3.

According to this embodiment, the following effects can be obtained.
[A] In the first state, the second and third input arms 20 and 30 are separated from the output arm 40, and in the second and third states, the first input arm 10 is separated from the output arm 40. Therefore, the first curve C1 Can intersect both the second and third curves C2 and C3. Therefore, the degree of freedom in design of each curve C1, C2, C3 is improved, and the optimum design becomes possible, which contributes to the reduction of fuel consumption and the improvement of output.
[B] Since the alternative device 60 is provided only with two alternative pins 61 and 62, it is more compact than the fourth embodiment in which three alternative pins are required.
[C] Since each of the input arms 10, 20, and 30 is provided with rollers 11, 21, and 31, friction is less than when the input arms 10, 20, and 30 are in sliding contact with the cams 9a, 9b, and 9c. It becomes smaller.
[D] By arranging the four pins 61, 62, 72, 73 on the center line of the three rollers 11, 21, 31, the four arms 10, 40, 20, and 30 are arranged in the second to third embodiments. It is more compact than 4.
[E] As in the variable valve mechanism 1a of the change example 1 shown in FIG. 6A, the positions of the switching pin 73 and the intervening pin 72 are exchanged from the state of this embodiment, so that both hydraulic chambers 66 and 76 It is also possible to bring the hydraulic pressure to the third state when the internal combustion engine is started. Further, as in the variable valve mechanism 1b of the second modification shown in FIG. 6B, by exchanging the positions of the spring S and the alternative hydraulic chamber 66 from the state of this embodiment, when the internal combustion engine is started. It can also be in the first state. Therefore, the state at the time of starting the internal combustion engine can be freely selected from the first, second and third states according to the properties of the internal combustion engine and the like. However, although it is not impossible to make it as in the second modification, it is necessary to bypass the alternative oil passage 67 so as to avoid the second roller 21 and pull it to the inside of the second roller 21. , Difficult or troublesome.

The second embodiment is different from the first embodiment in the following points, and is the same in other respects.
As shown in FIGS. 7 and 8, in the variable valve mechanism 2 of this embodiment, the intermediate portions in the length direction of the four arms 10, 40, 20, and 30 bulge downward. As shown in FIG. 9A, a first hole 16, a connecting hole 46, a second hole 26, and a third hole 36 are provided in a portion bulging downward. The first hole 16 is provided in the first input arm 10 and opens to the left L. An air bleeding hole E is formed in the bottom of the first hole 16. The connecting hole 46 is provided in the output arm 40 and is open to L and R on both the left and right sides. The second hole 26 is provided in the second input arm 20 and is open to L and R on both the left and right sides. The third hole 36 is provided in the third input arm 30 and opens to the right R. The center lines of the first hole 16, the connecting hole 46, the second hole 26, and the third hole 36 are aligned when the base circle is formed.

The first alternative pin 61 is installed in the first hole 16. The left portion of the first-choice pin 61 can protrude into the connecting hole 46. The second alternative pin 62 is installed in the right portion of the second hole 26. The right portion of the second alternative pin 62 can protrude into the connecting hole 46. The alternative displacement device 65 includes a spring S and an alternative hydraulic chamber 66. The spring S is installed between the inner bottom of the first hole 16 and the first alternative pin 61. The spring S urges the alternative pins 61 and 62 to the left L by its elastic force. The alternative hydraulic chamber 66 is provided in the second hole 26. The alternative oil passage 67 extends through the oil supply pipe 56 and the second input arm 20 to the alternative hydraulic chamber 66. The alternative hydraulic pressure chamber 66 presses both alternative pins 61 and 62 to the right R with the hydraulic pressure in the chamber.

The intervening pin 72 is installed in the left portion of the second hole 26. The switching pin 73 is installed in the third hole 36. The right portion of the switching pin 73 can protrude into the second hole 26. The switching displacement device 75 includes the alternative hydraulic chamber 66 and the switching hydraulic chamber 76. The alternative hydraulic chamber 66 is provided between the second alternative pin 62 and the intervening pin 72. The alternative hydraulic chamber 66 presses the intervening pin 72 and the switching pin 73 to the left L with the hydraulic pressure in the chamber. The switching hydraulic chamber 76 is provided between the inner bottom thereof and the switching pin 73 in the third hole 36.

As shown in FIG. 9A, when the hydraulic pressure of the alternative hydraulic chamber 66 becomes low and the hydraulic pressure of the switching hydraulic chamber 76 becomes low, the elastic force of the spring S causes the alternative pins 61 and 62 and the alternative pins 61 and 62. By urging the intervening pin 72 and the switching pin 73 to the left L, the alternative pins 61 and 62 are arranged at the first position, and the switching pin 73 is arranged at the non-connected position. Then, by arranging the alternative pins 61 and 62 at the first position, the first input arm 10 is connected to the output arm 40, and the first state is set. This first state is reached when the internal combustion engine is started.

As shown in FIG. 9B, when the hydraulic pressure of the alternative hydraulic chamber 66 becomes high pressure and the hydraulic pressure of the switching hydraulic chamber 76 becomes low pressure, the hydraulic pressure of the alternative hydraulic chamber 66 becomes the alternative pin 61, 62 is pressed to the right R, and the intervening pin 72 and the switching pin 73 are pressed to the left L. As a result, the alternative pins 61 and 62 are arranged at the second position and the switching pin 73 is arranged at the non-connected position. As a result, the second input arm 20 is connected to the output arm 40, and the third input arm 30 is not connected to the second input arm 20, resulting in a second state.

As shown in FIG. 9C, when the hydraulic pressure of the switching hydraulic chamber 66 becomes low pressure and the hydraulic pressure of the switching hydraulic chamber 76 becomes high pressure, the hydraulic pressure of the switching hydraulic chamber 76 becomes the alternative pins 61 and 62. Further, the intervening pin 72 and the switching pin 73 are pressed to the right R. As a result, the alternative pins 61 and 62 are arranged at the second position and the switching pin 73 is arranged at the connecting position. As a result, the second input arm 20 is connected to the output arm 40, and the third input arm 30 is connected to the second input arm 20 to enter the third state.

In this embodiment, the effects of the above [A] to [C] and the following effects of [E2] can be obtained.
[E2] In this embodiment, since the alternative hydraulic chamber 66 is provided at the lower part of the second input arm 20, unlike the second modification of the first embodiment, the alternative oil passage 67 is the second roller 21. Not blocked by. Therefore, the alternative oil passage 67 can be easily pulled to the alternative hydraulic chamber 66. Therefore, this embodiment can be carried out more easily than the modified example 2 of the first embodiment. Further, as in the variable valve mechanism 2a of the modified example 1 shown in FIG. 10 (a), by exchanging the positions of the spring S and the alternative hydraulic chamber 66 from the state of this embodiment, when the internal combustion engine is started. It can also be in the second state. Further, as in the variable valve mechanism 2b of the modified example 2 shown in FIG. 10 (b), the positions of the switching pin 73 and the intervening pin 72 are exchanged from the state of the modified example 1, so that the third position is obtained when the internal combustion engine is started. It can also be in a state. Therefore, the state at the time of starting the internal combustion engine can be freely selected from the first, second and third states according to the properties of the internal combustion engine and the like.

Example 3 differs from Example 1 in the following points and is the same in other respects.
As shown in FIGS. 11 and 12, in the variable valve mechanism 3 of the present embodiment, the intermediate portions of the second and third input arms 20 and 30 in the length direction bulge downward.

As shown in FIG. 13A, an air bleeding hole E is formed at the bottom of the first shaft 13. The second shaft 23 is a bottomed tubular shaft that opens to the right R. The third shaft 33 is a shaft that does not have a cylinder hole. The alternative displacement device 65 includes an alternative spring 69 and an alternative hydraulic chamber 66. The alternative spring 69 is installed in the first shaft 13 between its inner bottom and the first alternative pin 61. The alternative spring 69 urges the alternative pins 61 and 62 to the left L by its elastic force. The alternative hydraulic chamber 66 is provided in the second shaft 23 between its inner bottom and the second alternative pin 62. Oil is supplied to the alternative hydraulic chamber 66 from the alternative oil passage 67. The alternative oil passage 67 extends through the oil supply pipe 56 and the second input arm 20 to the alternative hydraulic chamber 66. The alternative hydraulic chamber 66 presses the alternative pins 61 and 62 to the right R with the hydraulic pressure in the chamber.

As shown in FIG. 13B, a second hole 26 and a third hole 36 are provided in a portion bulging downward of the second and third input arms 20 and 30. The second hole 26 is provided in the second input arm 20 and opens to the left L. An air bleeding hole E is formed in the bottom of the second hole 26. The third hole 36 is provided in the third input arm 30 and opens to the right R. The center lines of the second hole 26 and the third hole 36 are aligned when the base circle is formed.

The intervening pin 72 is installed in the second hole 26. The switching pin 73 is installed in the third hole 36. The switching displacement device 75 includes a switching spring 79 and a switching hydraulic chamber 76. The switching spring 79 is installed in the second hole 26 between its inner bottom and the intervening pin 72. The switching spring 79 urges the intervening pin 72 and the switching pin 73 to the left L by the elastic force thereof. The switching hydraulic chamber 76 is provided between the inner bottom thereof and the switching pin 73 in the third hole 36.

As shown in FIG. 14, when the hydraulic pressure of the alternative hydraulic pressure chamber 66 becomes low pressure and the hydraulic pressure of the switching hydraulic pressure chamber 76 becomes low pressure, the following occurs. That is, the alternative pins 61 and 62 are urged to the left L by the elastic force of the alternative spring 69, so that the alternative pins 61 and 62 are arranged at the first position. Further, the intervening pin 72 and the switching pin 73 are urged to the left L by the elastic force of the switching spring 79, so that the switching pin 73 is arranged at the non-connected position. Then, by arranging the alternative pins 61 and 62 at the first position, the first input arm 10 is connected to the output arm 40, and the first state is set. When the internal combustion engine is started, this first state is reached.

As shown in FIG. 15A, when the hydraulic pressure of the alternative hydraulic pressure chamber 66 becomes high pressure and the hydraulic pressure of the switching hydraulic pressure chamber 76 becomes low pressure, the following occurs, that is, the alternative hydraulic pressure chamber 66 By hydraulically pressing the alternative pins 61 and 62 to the right R, the alternative pins 61 and 62 are arranged at the second position. Further, the switching pin 73 is arranged at the non-connected position in the same manner as described above. As a result, the second input arm 20 is connected to the output arm 40, and the third input arm 30 is not connected to the second input arm 20, resulting in a second state.

As shown in FIG. 15B, when the hydraulic pressure of the alternative hydraulic pressure chamber 66 becomes high pressure and the hydraulic pressure of the switching hydraulic pressure chamber 76 becomes high pressure, the following occurs. That is, similarly to the above, the alternative pin 62 is arranged at the second position. Further, the intervention pin 72 and the switching pin 73 are pressed to the right R by the hydraulic pressure of the switching hydraulic chamber 76, so that the switching pin 73 is arranged at the connecting position. As a result, the second input arm 20 is connected to the output arm 40, and the third input arm 30 is connected to the second input arm 20 to enter the third state.

In this embodiment, the effects of the above [A] to [C] and the following effects of [E3] can be obtained.
[E3] In this embodiment, the alternative hydraulic chamber 66 is provided on the left L side of the inside of the second roller 21, so that the alternative oil passage 67 is different from the modification 2 of the first embodiment. It is not blocked by the second roller 21. Therefore, the alternative oil passage 67 can be easily pulled to the alternative hydraulic chamber 66. Therefore, this embodiment can be carried out more easily than the modified example 2 of the first embodiment. Further, as in the variable valve mechanism 3a of the modified example 1 shown in FIG. 16A, the positions of the alternative spring 69 and the alternative hydraulic chamber 66 are exchanged from the state of this embodiment, so that the internal combustion engine can be operated. It can also be set to the second state at startup. Further, as in the variable valve mechanism 3b of the modification 2 shown in FIG. 16B, the positions of the switching pin 73 and the intervening pin 72 are exchanged from the state of the modification 1, so that the third state is obtained when the internal combustion engine is started. It can also be. Therefore, the state at the time of starting the internal combustion engine can be freely selected from the first, second and third states according to the properties of the internal combustion engine and the like.

Example 4 differs from Example 3 in the following points and is the same in other respects.
As shown in FIG. 17, in the variable valve mechanism 4 of this embodiment, the output arm 40 is thickened in the width direction. The alternative device 60 includes three pins, a first intervening pin 63a, an alternative pin 63b, and a second intervening pin 63c. The first intervening pin 63a is displaceably installed in the first shaft 13 in the left-right directions L and R. The end face of the first intervening pin 63a is in contact with the end face of the alternative pin 63b. The alternative pin 63b is displaceably installed in the connecting hole 46 in the left-right directions L and R. The right portion of the alternative pin 63b can be projected into the first shaft 13, and the left portion can be projected into the second shaft 23. The second intervening pin 63c is displaceably installed in the second shaft 23 in the left-right directions L and R. The end face of the second intervening pin 63c is in contact with the end face of the alternative pin 63b.

As shown in FIG. 17A, when the hydraulic pressure of the alternative hydraulic chamber 66 becomes low, the three pins 63a, 63b, 63c are urged to the left L by the elastic force of the alternative spring 69. As a result, the alternative pin 63b is arranged at the second position. In the second position, the left portion of the alternative pin 63b straddles between the output arm 40 and the second input arm 20, and the contact portion between the alternative pin 63b and the first intervening pin 63a is the output arm 40 and the second position. It is a position between the input arm 10 and the input arm 10.

As shown in FIG. 17B, when the hydraulic pressure of the alternative hydraulic chamber 66 becomes high pressure, the three pins 63a, 63b, 63c are pressed to the right R by the hydraulic pressure of the alternative hydraulic chamber 66. The alternative pin 63b is arranged at the first position. In the first position, the right portion of the alternative pin 63b straddles between the output arm 40 and the first input arm 10, and the contact portion between the alternative pin 63b and the second intervening pin 63c is the output arm 40 and the first position. It is a position that comes between the two input arms 20.

In this example as well, the same effect as in Example 3 can be obtained except for the effect of [B] above.

1 Variable valve mechanism (Example 1)
1a Variable valve mechanism (Modification 1 of Example 1)
1b Variable valve mechanism (Modification 2 of Example 1)
2 Variable valve mechanism (Example 2)
2a Variable valve mechanism (Modification 1 of Example 2)
2b Variable valve mechanism (Modification 2 of Example 2)
3 Variable valve mechanism (Example 3)
3a Variable valve mechanism (Modification 1 of Example 3)
3b Variable valve mechanism (Modification 2 of Example 3)
4 Variable valve mechanism (Example 4)
9a 1st cam 9b 2nd cam 9c 3rd cam 10 1st input arm 11 1st roller 20 2nd input arm 21 2nd roller 30 3rd input arm 31 3rd roller 40 Output arm 60 Alternative device 61 1st alternative 1 pin 62 2nd alternative pin 65 Alternative displacement device 66 Alternative hydraulic chamber 69 Alternative spring 70 Switching device 73 Switching pin 75 Switching displacement device 76 Hydraulic chamber 77 Oil passage 79 Switching spring 85 Valve S spring L Left R Right C1 First curve C2 Second curve C3 Third curve

Claims (12)

The first input arm (10), which is driven by the first cam (9a) and swings,
The second input arm (20), which is driven by the second cam (9b) and swings,
The third input arm (30), which is driven by the third cam (9c) and swings,
The output arm (40) that drives the valve (85) during rocking,
An alternative device (60) that selectively connects either the first input arm (10) or the second input arm (20) to the output arm (40).
The second input arm (20) includes a switching device (70) for switching between a state in which the third input arm (30) is not connected and a state in which the third input arm (30) is connected.
When the first input arm (10) is connected to the output arm (40), it is in the first state, the second input arm (20) is connected to the output arm (40), and the second input arm (20) is connected to the first state. If the three input arms (30) are not connected, the second state is reached, the second input arm (20) is connected to the output arm (40), and the third input arm (30) is connected to the second input arm (20). When it is done, it will be in the third state,
The second curve (C2) showing the valve lift amount with respect to the rotation angle of the internal combustion engine in the second state is a region below the third curve (C3) showing the valve lift amount with respect to the rotation angle of the internal combustion engine in the third state ( Fits in r)
The first curve (C1) indicating the valve lift amount with respect to the rotation angle of the internal combustion engine in the first state is a variable valve mechanism of the internal combustion engine that intersects both the second curve (C2) and the third curve (C3). The alternative device (60) is provided with an alternative hydraulic chamber (66), and when the hydraulic pressure in the alternative hydraulic chamber (66) becomes a relatively low low pressure, the output arm (40) is connected to the first input arm (10). ), And the second input arm (20) is connected to the output arm (40) when the pressure becomes relatively high.
The variable valve mechanism for an internal combustion engine according to claim 1, wherein when the internal combustion engine is started, the hydraulic pressure in the alternative hydraulic chamber (66) becomes low pressure to be in the first state. The alternative device (60) includes an alternative hydraulic chamber (66), and when the hydraulic pressure in the alternative hydraulic chamber (66) becomes a relatively low low pressure, the output arm (40) is connected to the second input arm (20). ), And the first input arm (10) is connected to the output arm (40) when the pressure becomes relatively high.
The switching device (70) is provided with a switching hydraulic chamber (76), and when the hydraulic pressure in the switching hydraulic chamber (76) becomes a relatively low low pressure, the second input arm (20) becomes the third input arm (30). The third input arm (30) is connected to the second input arm (20) when the pressure becomes relatively high without connecting the above.
The internal combustion engine according to claim 1, wherein when the internal combustion engine is started, the hydraulic pressure in the alternative hydraulic chamber (66) becomes low and the hydraulic pressure in the switching hydraulic chamber (76) becomes low, so that the second state is reached. Variable valve mechanism. The alternative device (60) includes an alternative hydraulic chamber (66), and when the hydraulic pressure in the alternative hydraulic chamber (66) becomes a relatively low low pressure, the output arm (40) is connected to the second input arm (20). ), And the first input arm (10) is connected to the output arm (40) when the pressure becomes relatively high.
The switching device (70) is provided with a switching hydraulic chamber (76), and when the hydraulic pressure in the switching hydraulic chamber (76) becomes a relatively low low pressure, the second input arm (20) becomes the third input arm (30). Is configured so that the connection is not made when the pressure becomes relatively high.
The internal combustion engine according to claim 1, wherein when the internal combustion engine is started, the hydraulic pressure in the alternative hydraulic chamber (66) becomes low and the hydraulic pressure in the switching hydraulic chamber (76) becomes low, so that the third state is reached. Variable valve mechanism. The alternative device (60) is
A first-choice pin (61) attached to the first input arm (10) so as to project toward the output arm (40), and
The second alternative pin (62), which is attached to the second input arm (20) so as to project toward the output arm (40) and whose end face is in contact with the end face of the first alternative pin (61).
The alternative pins (61,62) straddle the output arm (40) and the first input arm (10), and the first alternative pins (61) straddle the alternative pins (61, 62). The first position where the contact portion comes between the output arm (40) and the second input arm (20), and the second alternative pin (62) is the output arm (40) and the second input arm (20). It straddles between 20) and is displaced to the second position where the contact portion between the alternative pins (61, 62) comes between the output arm (40) and the first input arm (10). It is configured to include an alternative displacement device (65).
The switching device (70) is
A switching pin (73) displaceable between a connecting position that straddles the second input arm (20) and the third input arm (30) and a non-connecting position that does not straddle the second input arm (20).
The variable valve mechanism for an internal combustion engine according to claim 1, further comprising a switching displacement device (75) that displaces a switching pin (73) between a connected position and a non-connected position. The first input arm (10) includes a first roller (11) that abuts on the first cam (9a).
The second input arm (20) includes a second roller (21) that abuts on the second cam (9b).
The variable valve mechanism for an internal combustion engine according to claim 5, wherein the third input arm (30) includes a third roller (31) that abuts on the third cam (9c). When viewed in the state of the base circle, the alternative pins (61, 62) and the switching pins (73) are provided in a straight line on the center lines of the first, second and third rollers (11, 21, 31). The variable valve mechanism of the internal combustion engine according to claim 6. When viewed in the state of the base circle, the alternative pins (61, 62) and the switching pins (73) are aligned at positions different from those on the center line of the first, second or third rollers (11, 21, 31). The variable valve mechanism of an internal combustion engine according to claim 6, which is provided on the wire. When viewed in the state of the base circle, the alternative pins (61, 62) are provided in a straight line on the center lines of the first and second rollers (11, 21), and the switching pins (73) are on the center line. The variable valve mechanism of the internal combustion engine according to claim 6, which is provided at a position different from that of the internal combustion engine. The alternative displacement device (65) is an alternative hydraulic chamber (66) that presses the alternative pins (61, 62) in one direction (L) in the length direction of the straight line with the hydraulic pressure in the room. A spring that urges the pins (61, 62) to the other (R) in the length direction of the straight line with an elastic force and urges the switching pin (73) to the other (L) in the length direction of the straight line by the reaction force. Consists of including (S)
The switching displacement device (75) includes the spring (S) and the switching hydraulic chamber (76) that presses the switching pin (73) in the other (R) in the length direction of the straight line with the hydraulic pressure in the room. The variable valve mechanism of the internal combustion engine according to claim 7 or 8. The alternative displacement device (65) includes a spring (S) that elastically urges the alternative pins (61, 62) in one direction (L) in the length direction of the straight line, and the alternative pins (61, 62). The alternative hydraulic chamber (66) that presses 62) with the hydraulic pressure in the room in the other (R) in the length direction of the straight line and presses the switching pin (73) in one direction (L) in the length direction of the straight line. Consists of
The switching displacement device (75) is a switching hydraulic chamber (76) that presses the alternative hydraulic chamber (66) and the switching pin (73) in the other (R) in the length direction of the straight line with the hydraulic pressure in the room. The variable valve mechanism of the internal combustion engine according to claim 7 or 8, which is configured to include. The alternative displacement device (65) includes an alternative spring (69) that urges the alternative pin (61, 62) in one direction in the length direction of the straight line with an elastic force, and an alternative pin (61, 62). 62) is configured to include an alternative hydraulic chamber (66) that presses the other in the length direction of the straight line with hydraulic pressure in the chamber.
The switching displacement device (75) has a switching spring (79) that urges the switching pin (73) to one side (L) in the length direction by an elastic force, and the switching pin (73) to the other side in the length direction (L). The variable valve mechanism of an internal combustion engine according to claim 9, wherein R) includes a hydraulic pressure chamber (76) for switching that is pressed by hydraulic pressure in the chamber.

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