JP4813399B2 - Variable valve mechanism - Google Patents

Description

  The present invention relates to a variable valve mechanism that changes the opening / closing amount of a valve stepwise in accordance with the operating condition of an internal combustion engine.

  Among this type of variable valve mechanism, an inner arm 113 having an input roller 114 that abuts against the rotating cam 111, as in the variable valve mechanism 110 of the first prior art shown in FIGS. A rocker arm 112 comprising an outer arm 115 arranged on both sides and abutting the valve 7 is provided, and a connection state in which the inner arm 113 and the outer arm 115 are connected to each other so as not to be relatively displaceable by the switching mechanism 116 and a connection in which the connection is released There is one that changes the opening / closing amount of the valve 7 by switching between the released states (Patent Document 1).

  The switching will be described in more detail. The switching mechanism 116 includes two connecting pins 117 arranged side by side inside the hollow shaft 114x that pivotally supports the input roller 114 and inside the outer arm 115 located on the extension line thereof. Is pushed by the pin driving mechanism 118 provided outside the rocker arm 112 via the intermediate pin 119, and is displaced between a position straddling between the inner arm 113 and the outer arm 115 and a position not straddling. Thus, switching between the connected state and the disconnected state is performed.

In addition, like the variable valve mechanism 120 of the second conventional example shown in FIG. 10, a rocker arm 122 including an inner arm 123 having an input roller 124 at an intermediate portion in the longitudinal direction and outer arms 125 arranged on both sides thereof. The connecting pin 127 provided at the base end portion of the inner arm 123 and the outer arm 125 is moved over the position and straddling between the inner arm 123 and the outer arm 125 by a hydraulic mechanism 128 provided inside the inner arm 123. There is also one that switches between a connected state and a disconnected state by displacing between positions where there is no valve and changes the opening / closing amount of the valve 7 by the switching (Patent Document 2).
US Patent Application Publication No. 2005/132990 US Patent Application Publication No. 2004/74459

  However, in the conventional example 1, the pin driving mechanism 118 that drives the connecting pin 117 is required outside the rocker arm 112, so that the number of parts increases and the structure of the switching mechanism becomes complicated. In addition, since the shaft has a double shaft structure in which the connecting pin 117 is arranged inside the hollow shaft 114x that pivotally supports the input roller 114, the number of parts increases, and the structure of the inner arm 113 including the input roller 114 is complicated. turn into.

  In the second conventional example, since the hydraulic mechanism 128 that drives the connecting pin 127 is provided inside the inner arm 123, no pin driving mechanism is required outside the rocker arm 122. This structure is simpler than that of the first embodiment, but here, the connection between the inner arm 123 and the outer arm 125 and the release of the inner arm 123 and the outer arm 125 are separated from the input roller 124 to which the power source is input. Therefore, the change of the movement of the rocker arm 122 between the connected state and the disconnected state becomes complicated, and accordingly, the structure of the rocker arm 122 becomes complicated.

  Therefore, the first object is to simplify the structure of the switching mechanism without complicating the change or structure of the movement of the rocker arm, and the second object is to simplify the structure of the input member including the input roller. To do.

  In order to achieve the first object, a variable valve mechanism according to the present invention includes a rocker arm including an input member having an input roller that rotatably contacts a rotating cam, and an output member that contacts the valve, and the input member. And a switching mechanism for switching between a connected state in which the output member and the output member are connected to each other so as not to be relatively displaceable and a released state in which the connection is released, and the opening / closing amount of the valve is changed by the switching. In the variable valve mechanism, the switching mechanism is provided to be displaceable between a position straddling between the input member and the output member and a position not straddling in the axial direction on the axis of the input roller. And a hydraulic chamber provided inside the rocker arm for hydraulically driving the coupling pin, and an oil passage for supplying the hydraulic pressure to the hydraulic chamber.

To achieve the above second object, the connecting pin is inserted into the shaft holes formed through the axis of the input roller, characterized in that axially supports the input roller. This is because the hollow shaft as shown in the conventional example 1 can be omitted by pivotally supporting the input roller with the connecting pin itself.

  The change in the opening / closing amount of the valve here is not particularly limited, but switching is performed between a driving state in which the valve is driven according to the rotation of the rotating cam and a driving stop state in which the driving is completely stopped. Another example is a case of switching between a high lift state in which the valve is opened and closed with a relatively large lift amount and a low lift state in which the valve is opened and closed with a relatively small lift amount according to the rotation of the rotating cam.

  The rocker arm is not particularly limited, but includes a rocking center portion at the rear end portion (base end portion), the input roller at the middle portion in the length direction, and the valve abutting on the front end portion, For example, the input roller may be provided in the part, the swinging central part may be provided in the middle in the length direction, and the valve may be in contact with the tip part.

Further, the rocker arm is not particularly limited, but the following forms (i) and (ii) can be given as examples.
(I) One rocker arm drives the two valves.
(Ii) One rocker arm drives one valve.

In addition, the input member and the output member of the rocker arm are not particularly limited, but examples include the following (1) to (3).
(1) In the case where the input member is an inner arm provided to be relatively swingable inward, and the output member is an outer arm provided to be swingable relatively outward.
(2) When the input member and the output member are one and the other of a left arm and a right arm provided side by side, respectively.
(3) The output member is an arm main body provided to be swingable, and the input member is a displacement member attached to the arm main body so as to be capable of relative displacement.

  The arrangement of each component of the variable valve mechanism is not particularly limited, but the rocker arm is attached to the tip of a lash adjuster, and the oil passage is routed through the inside of the lash adjuster and the rocker arm. Take as an example.

  Further, the hydraulic chamber is not particularly limited, but the output member has an opening recessed toward the input member, and one end of the connection pin is inserted in the connected state, and in the disconnected state. In the hole of the bottomed hole from which the one end is removed, the opening is closed by the inserted connecting pin in the connected state, and in the disconnected state, the removed connecting pin and the input member And the opening is closed, and between the hydraulic chamber and the connecting pin, without being pulled out from the bottomed hole in both the connected state and the disconnected state. It is preferable that a closing pin for closing the opening is not interposed. This is because by not providing the closing pin, the number of parts can be reduced and the structure of the switching mechanism can be simplified.

  The switching mechanism is not particularly limited, and includes a spring that biases the connecting pin in a direction against the hydraulic pressure, and the spring extends in a length direction of the rocker arm attached to a side surface of the rocker arm. A leaf spring is preferred. This is because, if the spring is made of such a leaf spring, the spring is less bulky than the case of using a coil spring, and space saving can be realized.

  Further, the structure for supporting the rocker arm so as to be swingable is not particularly limited, but a lash adjuster in which a fulcrum pin that pivotally supports the rocker arm is disposed on a length direction side of the fulcrum pin of the pivotally supported portion. It is preferable that the rocker arm is supported so as to be swingable. With such a structure, it is difficult for the rocker arm to be separated from the lash adjuster, and the rocker arm is difficult to tilt in the width direction. Further, at this time, the lash adjuster is not particularly limited, but it is preferable that one lash adjuster is arranged on each side of the rocker arm, and the fulcrum pins are supported by the pair of lash adjusters from both sides. This is because such a structure makes it more difficult to disperse and more difficult to tilt.

  According to the present invention, since the switching mechanism includes the hydraulic chamber inside the rocker arm, there is no need to separately provide a pin driving mechanism for driving the connecting pin outside the rocker arm as in Conventional Example 1. Therefore, the structure of the switching mechanism is simplified. Further, since the connecting pin of the switching mechanism is on the axis of the input roller, the change in the movement of the rocker arm between the connected state and the disconnected state is complicated as in the conventional example 2, and accordingly, The structure of the arm is not complicated.

  Further, if the input roller is pivotally supported by the connecting pin, a double shaft structure comprising a hollow shaft for pivotally supporting the input roller and a connecting pin arranged in the interior as shown in the conventional example 1 is achieved. In addition, the structure of the input member can be simplified.

  The variable valve mechanism 9 according to the present invention includes a rocker arm 20 including an input member 21 having an input roller 23 that rotatably contacts the rotating cam 10, and an output member 26 that contacts the valve 7, and the input member 21 and the output member. 26 is configured to include a switching mechanism 40 that switches between a connected state in which the two are connected to each other so as not to be relatively displaceable and a disconnected state in which the connection is released, and the opening / closing amount of the valve 7 is changed by the switching.

  The switching mechanism 40 includes a connecting pin 45 provided so as to be displaceable between a position straddling between the input member 21 and the output member 26 and a position not straddling in the axial direction on the axis of the input roller 23. A hydraulic chamber 53 provided inside the rocker arm 20 that drives the connecting pin 45 with hydraulic pressure, and an oil passage 54 that supplies the hydraulic pressure to the hydraulic chamber 53 are configured. The connecting pin 45 is inserted into the shaft hole 24 penetrating the shaft center of the input roller 23 and pivotally supports the input roller 23.

  The variable valve mechanism 9 shown in FIGS. 1 to 3 according to the first embodiment is a mechanism that changes the opening / closing amount of the valve stepwise in accordance with the operating state of the internal combustion engine. In the first embodiment, the variable valve mechanism 9 is provided only for half of the cylinders 5 (not shown), and each variable valve mechanism 9 is connected to each cylinder 5. The two intake valves 7 are respectively driven. The variable valve mechanism 9 is interposed between a rotary cam 10 that rotates in accordance with the rotation of the internal combustion engine, a valve spring 15 that biases the valve 7 in a closing direction, and a rotary cam 10 and the valve 7 that can swing. The rocker arm 20 and a switching mechanism 40 for switching the state of the rocker arm 20 are configured to switch between a driving state in which the valve 7 is driven according to the rotation of the rotary cam 10 and a driving stop state in which the driving is stopped. Switch with.

  The rotary cam 10 is formed on a camshaft 10x that is rotationally driven as the internal combustion engine operates, and includes a base circle portion 11 that is a basic portion and a cam nose 12 that protrudes from the base circle portion 11. Has been. The rotating cam 10 is disposed above the rocker arm 20, and a cam surface 10 s that presses the input roller 23 of the rocker arm 20 is formed on the outer peripheral surface of the rotating cam 10. In FIG. 1, for the sake of convenience, the rotating cam 10 and the camshaft 10x are indicated by a two-point difference line.

  The rocker arm 20 is a two-valve integrated arm that drives the two valves 7 simultaneously, and includes an input member 21 that contacts the rotating cam 10 and an output member 26 that contacts the valve 7.

  Specifically, the input member 21 is an inner arm provided on the inner side of the output member 26, and includes a fulcrum hole 22 in the form of a through-hole to be supported by the lash adjuster 30 at the base end portion. In addition, an input roller 23 that rotatably contacts the rotary cam 10 is provided at the tip. A lost motion spring 35 is attached between the input member 21 and the cylinder head 6 to urge the input member 21 toward the rotary cam 10.

  The output member 26 is an outer arm that is provided on both outer sides of the input member 21 and is longer on the distal end side than the input member 21, and is supported at the base end portion so as to be swingable by the lash adjuster 30. A through-hole-shaped fulcrum hole 27 is provided, and a curved output surface 28 that contacts the stem end 7e of the valve 7 is provided at the tip.

  The input member 21 and the output member 26 are supported above the cylinder head 6 as follows. That is, the base end portions of the input member 21 and the output member 26 are pivotally supported by fulcrum pins 32, and the fulcrum pins 32 are separated from both sides by a pair of lash adjusters 30 arranged on both sides in the length direction. It is supported. Specifically, each lash adjuster 30 has an upper ring shape with a support hole 31 in the form of a through hole in the upper part, and the support hole 31 of the lash adjuster 30, the fulcrum hole 22 of the input member 21, and the output By inserting a single fulcrum pin 32 into the fulcrum hole 27 of the member 26 across the holes, the base end of the input member 21 and the output member 26 is connected to the cylinder head 6. Is swingably supported above. Therefore, in the first embodiment, the rocker arm 20 is not easily separated from the lash adjuster 30 and the rocker arm 20 is not easily tilted in the width direction as compared with the case where the upper hemispherical lash adjuster that only mounts the rocker arm is used. It has become.

  The switching mechanism 40 is a mechanism that switches between a connection state in which the input member 21 and the output member 26 are connected to each other so that they cannot be displaced relative to each other, and a connection release state in which the connection is released. Switches between the above-described driving state and driving stop state by the switching. The switching mechanism 40 includes a connecting pin 45 provided so as to be displaceable between a position straddling between the input member 21 and the output member 26 and a position not straddling in the axial direction on the axis of the input roller 23. The hydraulic mechanism 51 presses the connecting pin 45 in one direction with hydraulic pressure, and the spring 56 presses the connecting pin 45 in the other direction opposite to the one direction. Specifically, the switching mechanism 40 is configured to release the connection by driving the connecting pin 45 in one direction with the hydraulic pressure of the hydraulic mechanism 51, and to drive in the other direction with the pressing force of the spring 56 by releasing the hydraulic pressure. Connected.

  The connecting pin 45 is attached to a pin hole 41 provided in the rocker arm 20 so as to be displaceable in the length direction of the hole. Specifically, the pin hole 41 includes a bottomed hole-shaped first hole 42 that is recessed in the lengthwise intermediate portion of one output member 26 with the opening directed toward the input member 21, and the distal end portion of the input member 21. A through-hole-shaped second hole 43 penetrating into the second output member 26, and a bottomed-hole-shaped third hole 44 recessed in the lengthwise intermediate portion of the other output member 26 toward the input member 21. It is comprised including. The second hole 43 penetrates the axis of the input roller 23 in the axial direction. Therefore, the second hole 43 includes the shaft hole 24 penetrating the axis of the input roller 23 as a constituent element. It is out. The connection pin 45 is housed in the second hole 43 when in the disconnected state, the first pin 46 straddling between the first hole 42 and the second hole 43 when in the connected state, and the third pin when in the disconnected state. It includes a second pin 47 that is accommodated in the hole 44 and straddles between the second hole 43 and the third hole 44 when connected. The first pin 46 is hollow as shown in the conventional example 1 without being removed from the shaft hole 24 of the input roller 23 in either the connected state or the disconnected state. The shaft is also inserted alone without any interposition, and the connecting roller 45 supports the input roller 23 via the bearing 25.

  The spring 56 is a coil spring that presses the connecting pin 45 toward the first hole 42, and is interposed between the bottom surface of the third hole 44 and the second pin 47.

  The hydraulic mechanism 51 is a mechanism that presses the connecting pin 45 toward the third hole 44. The hydraulic mechanism 51 includes a hydraulic chamber 53 provided inside the output member 26 that drives the connecting pin 45 with hydraulic pressure, and an oil passage 54 that supplies hydraulic pressure to the hydraulic chamber 53. Specifically, the hydraulic mechanism 51 includes a closing pin 52 that closes the first hole 42 between the bottom surface of the first hole 42 and the first pin 46. The aforementioned hydraulic chamber 53 is formed therebetween. The oil passage 54 communicates with the hydraulic chamber 53, and the oil passage 54 passes through the cylinder head 6, one lash adjuster 30, the fulcrum pin 32, and the one output member 26. . The hydraulic mechanism 51 changes the hydraulic pressure supplied from the oil passage 54 to the hydraulic chamber 53, and changes the hydraulic pressure in the hydraulic chamber 53 to cooperate the spring 56 with the connecting pin 45 in one direction and the above. Drive in the other direction.

  The state of the variable valve mechanism 9 described above will be described below separately for (1) when the internal combustion engine is rotating at a low speed and (2) when the internal combustion engine is rotating at a high speed.

(1) During low-speed rotation of the internal combustion engine At this time, as shown in FIG. 2A, when the hydraulic pressure in the hydraulic chamber 53 increases, the two pins 46, 47 are connected by the hydraulic pressure via the closing pin 52. The connecting pin 45 including is driven toward the third hole 44 against the pressing force of the spring 56. At this time, the closing pin 52 is accommodated in the first hole 42, the first pin 46 is accommodated in the second hole 43, and the second pin 47 is accommodated in the third hole 44. Therefore, neither the first pin 46 nor the second pin 47 crosses between the holes 42, 43, 44, so that the connection state is released, and the input member 21 and the output member 26 are connected to their respective base ends. Relative rotation is possible about the part. Therefore, at this time, as shown in FIGS. 3A and 3B, the input member 21 swings independently from the output member 26 according to the rotation of the rotary cam 10. For this reason, when in this disconnected state, the valve 7 is in a drive stop state, and therefore, half of the cylinders 5 in which the variable valve mechanism 9 is installed are not inhaled, and only the remaining half of the cylinders. The internal combustion engine is operated by the output from.

(2) During high-speed rotation of the internal combustion engine At this time, as shown in FIG. 2 (b), the hydraulic pressure in the hydraulic chamber 53 decreases, so that the connecting pin 45 including the two pins 46 and 47 is pushed by the spring 56. The pressure is pushed back to the first hole 42 side. At this time, the first pin 46 is arranged at a position straddling between the first hole 42 and the second hole 43, and the second pin 47 is at a position straddling between the second hole 43 and the third hole 44. It will be arranged and will be in a connection state by these. Therefore, at this time, as shown in FIGS. 3C and 3D, the rocker arm 20 is integrated with the input member 21 and the output member 26 in accordance with the rotation of the rotary cam 10 around the respective base ends. The valve 7 is swung, and the valve 7 is pressed downward and driven by the output surface 28 at the tip of the output member 26. For this reason, in this connected state, intake is also performed to the cylinder 5 in which the variable valve mechanism 9 is installed, and the internal combustion engine is operated by the output from all the cylinders.

  According to the first embodiment, since the switching mechanism 40 includes the hydraulic chamber 53 inside the output member 26, a pin driving mechanism that drives the connecting pin 45 outside the rocker arm 20 is provided as in the first conventional example. In addition, there is no need to provide it separately, and thus the structure of the switching mechanism 40 is simplified. Further, since the connecting pin 45 of the switching mechanism is on the axis of the input roller 23, the change in the movement of the rocker arm 20 between the connected state and the disconnected state becomes complicated as in the conventional example 2. In addition, the structure of the arm is not complicated.

  Further, since the input roller 23 is pivotally supported by the first pin 46 itself, it is not necessary to separately provide a hollow shaft for pivotally supporting the input roller 23 as in the conventional example 1, and therefore, as in the conventional example 1. The structure of the input member 21 is simplified without the need for a double shaft structure.

  Further, since the oil passage 54 of the switching mechanism 40 passes through the hydraulic lash adjuster 30, the oil passage 54 for the switching mechanism 40 and the oil passage for the lash adjuster 30 are provided. As much as possible within the range in which the oil passage can be shared, the structure of the variable valve mechanism 9 is also simplified.

  A variable valve mechanism 59 shown in FIG. 4 of the second embodiment is substantially the same as that of the first embodiment, but only the switching mechanism 60 is different from the switching mechanism 40 of the first embodiment. That is, contrary to the first embodiment, the switching mechanism 60 is connected by driving the connecting pin 65 in one direction with the hydraulic pressure of the hydraulic mechanism 51, loosening the hydraulic pressure and pressing in the other direction with the pressing force of the spring 56. To the disconnected state. Only differences from the first embodiment will be described below.

  The connecting pin 65 of the switching mechanism 60 is housed in the first hole 42 when in the disconnected state, and the first pin 66 straddling between the first hole 42 and the second hole 43 when in the connected state, and the disconnected state. Is contained in the second hole 43, and in the connected state, a second pin 67 straddling between the second hole 43 and the third hole 44 is included. The hydraulic chamber 53 of the hydraulic mechanism 51 is formed between the bottom surface of the first hole 42 and the first pin 66 that also serves as a closing pin that closes the first hole 42. The switching mechanism 60 includes an intermediate pin 68 that transmits the pressing force from the spring 56 to the connection pin 65 on the third hole 44 side of the second pin 67. The spring 56 is connected to the intermediate pin 68 and the third pin 68. It is interposed between the bottom surface of the hole 44.

  The state of the variable valve mechanism 9 described above will be described below separately for (1) when the internal combustion engine is rotating at a low speed and (2) when the internal combustion engine is rotating at a high speed.

(1) When the internal combustion engine rotates at a low speed At this time, as shown in FIG. 4A, the hydraulic pressure in the hydraulic chamber 53 decreases, so that the connecting pin 65 including the two pins 66 and 67 is pushed by the spring 56. The pressure is pushed back to the first hole 42 side via the intermediate pin 68. At this time, the first pin 66 is accommodated in the first hole 42, the second pin 67 is accommodated in the second hole 43, and the intermediate pin 68 is accommodated in the third hole 44. Therefore, neither the first pin 66 nor the second pin 67 crosses between the holes 42, 43, 44, so that the connection is released.

(2) During high-speed rotation of the internal combustion engine At this time, as shown in FIG. 4B, when the hydraulic pressure in the hydraulic chamber 53 increases, the connection pin 65 including the two pins 66 and 67 is generated by the hydraulic pressure. It is driven to the third hole 44 side against the pressing force of the spring 56. At this time, the first pin 66 is arranged at a position straddling between the first hole 42 and the second hole 43, and the second pin 67 is at a position straddling between the second hole 43 and the third hole 44. It will be arranged and will be in a connection state by these.

  According to the second embodiment, contrary to the first embodiment, the connected state can be set when the hydraulic pressure is increased, and the disconnected state can be set when the hydraulic pressure is decreased.

  The variable valve mechanism 69 shown in FIGS. 5 and 6 of the third embodiment is different from the first embodiment in that a rotating cam 10 and a rocker arm 70 are provided for each intake valve 7. This is different from the two variable valve mechanisms 9 and 59. Only differences from the first embodiment will be described below.

  The rocker arm 70 is an arm that drives one valve 7, and includes an input member 71 that contacts the rotating cam 10 and an output member 76 that contacts the valve 7. The rocker arm 70 is configured based on four plates 70a, 70b, 70c, and 70d.

  Specifically, the input member 71 is an inner arm configured based on a pair of plates 70a and 70b disposed on the inner side of the output member 76. The input member 71 is connected to the lash adjuster 30 at the base end portion of both the plates 70a and 70b. A fulcrum hole 72 in the form of a through hole to be supported so as to be swingable is provided, and an input roller 73 that rotatably contacts the rotating cam 10 is provided between the tip portions of both plates 70a and 70b. . Further, a protruding portion 71p for closing an opening of a first hole 82 described later is provided on the upper portion of the input member 71. A lost motion spring 35 is attached between the input member 71 and the cylinder head 6 to urge the input member 71 toward the rotary cam 10.

  The output member 76 is an outer arm provided on the outer side of the input member 71 and having a pair of plates 70c and 70d that are longer than the input member 71 on the front end side. A fulcrum hole 77 in the form of a through-hole is provided at the base end portion so as to be swingably supported by the lash adjuster 30, and both the plates 70 c and 70 d are connected to the distal end portion. An output shaft 78 in contact therewith is provided.

  The input member 21 and the output member 26 are supported above the cylinder head 6 as follows. That is, the base end portions of the input member 21 and the output member 26 are pivotally supported by a fulcrum pin 79, and the fulcrum pin 79 is arranged between the two plates 70 a and 70 b constituting the input member 71. The same lash adjuster 30 as that of the first embodiment is supported. Specifically, a single fulcrum pin 79 is inserted into the support hole 31 of the lash adjuster 30, the fulcrum hole 22 of the input member 21, and the fulcrum hole 27 of the output member 26 across the holes. Thus, the base end portions of the input member 21 and the output member 26 are supported above the cylinder head 6 so as to be swingable. Therefore, in the third embodiment, similarly to the first embodiment, the rocker arm 70 is not easily separated from the lash adjuster 30 as compared with the case where the upper hemispherical lash adjuster that only mounts the rocker arm is used. 70 hardly tilts in the width direction.

  The switching mechanism 80 includes, in the axial direction on the axis of the input roller 73, a connecting pin 85 provided so as to be displaceable between a position straddling between the input member 71 and the output member 76 and a position not straddling. A hydraulic mechanism 91 that presses the connecting pin 85 in one direction with hydraulic pressure and a spring 96 that presses the connecting pin 85 in the other direction opposite to the one direction are configured. Specifically, the switching mechanism 80 is configured to release the connection by driving the connecting pin 85 in one direction with the hydraulic pressure of the hydraulic mechanism 91, and to drive in the other direction with the pressing force of the spring 96 by releasing the hydraulic pressure. Connected.

  The connecting pin 85 is attached to a pin hole 81 provided in the rocker arm 70 so as to be displaceable in the length direction of the hole. Specifically, the pin hole 81 includes a bottomed hole-shaped first hole 82 that is recessed in the lengthwise intermediate portion of the one plate 70 c of the output member 76 toward the input member 71, and the input member 71. A through hole-shaped second hole 83 penetrating at the tip of the output member 76 and a through-hole-shaped third hole 84 penetrating the intermediate portion in the longitudinal direction of the other plate 70d of the output member 76. ing. The second hole 83 penetrates the axis of the input roller 73 in the axial direction. Therefore, the second hole 83 includes a shaft hole 74 that penetrates the axis of the input roller 73 as a constituent element. It is out. The connection pin 85 is housed in the second hole 83 when the connection is released, the first pin 86 straddling between the first hole 82 and the second hole 83 when the connection is established, and the third pin when the connection is released. The second pin 87 is accommodated in the hole 84 and straddles between the second hole 83 and the third hole 84 when in the connected state. The first pin 86 is inserted into the shaft hole 74 of the input roller 73 alone as in the first embodiment, and the input roller 73 is pivotally supported via the bearing 75 by the connecting pin 85 itself.

  The spring 96 is a leaf spring that presses the connecting pin 85 toward the first hole 82, and extends outside the third hole 84 along the side surface of the output member 76 in the length direction of the output member 76. It is attached to the side surface.

  The hydraulic mechanism 91 is a mechanism that presses the connecting pin 85 toward the third hole 84. The hydraulic mechanism 91 includes a hydraulic chamber 93 provided inside the output member 76 that drives the connecting pin 85 with hydraulic pressure, and an oil passage 94 that supplies hydraulic pressure to the hydraulic chamber 93.

  Specifically, when the hydraulic chamber 93 is in a connected state in the hole of the first hole 82, the opening of the hole is closed by the end surface of the connecting pin 85 inserted into the first hole 82, and when the connected state is released, The opening is closed by the end face of the connecting pin 85 removed from the first hole 82 and the side face of the input member 71. Therefore, between the hydraulic chamber 93 and the connecting pin 85, the opening of the hole is not pulled out from the first hole in any of the connected state and the disconnected state as shown in the first embodiment. There is no intervening pin that closes. The oil passage 94 communicates with the hydraulic chamber 93, and the oil passage 94 passes through the cylinder head 6, the lash adjuster 30, the fulcrum pin 79, and the inside of one plate 70 c of the output member 76. Yes. The hydraulic mechanism 51 changes the hydraulic pressure supplied from the oil passage 94 to the hydraulic chamber 93, and changes the hydraulic pressure in the hydraulic chamber 93 to cooperate the spring 96 with the connecting pin 85 in one direction and Drive in the other direction.

  The state of the variable valve mechanism 9 described above will be described below separately for (1) when the internal combustion engine is rotating at a low speed and (2) when the internal combustion engine is rotating at a high speed.

(1) At the time of low speed rotation of the internal combustion engine At this time, as shown in FIG. It is driven to the third hole 84 side against the pressing force of 96. At this time, the first pin 86 is accommodated in the second hole 83, and the second pin 87 is accommodated in the third hole 84. Therefore, the first pin 86 and the second pin 87 do not straddle each other of the holes 82, 83, and 84, so that the connection state is released, and the input member 71 and the output member 76 are connected to their respective base ends. Relative rotation is possible about the part. Therefore, at this time, as shown in FIGS. 6A and 6B, the input member 71 swings independently from the output member 76 in accordance with the rotation of the rotary cam 10. For this reason, in this disconnected state, the valve 7 is in a drive stop state, and therefore, half of the cylinders 5 in which the variable valve mechanism 69 is installed are not inhaled, and only the remaining half of the cylinders. The internal combustion engine is operated by the output from.

  At this time, as shown in FIGS. 6C and 6D, the opening of the first hole 82 includes the end surface of the connecting pin 85 housed in the second hole 83 and the side surface of the input member 71. It is blocked by. In particular, as shown in FIG. 6 (d), when the valve 7 is displaced to near the bottom of its stroke, the opening of the first hole 82 is blocked by the protrusion 71 p of the input member 71. Is done.

(2) During high-speed rotation of the internal combustion engine At this time, as shown in FIG. 5 (b), the hydraulic pressure in the hydraulic chamber 53 decreases, so that the connecting pin 85 including the two pins 86 and 87 is pushed by the spring 96. The pressure is pushed back to the first hole 82 side. At this time, the first pin 86 is disposed at a position straddling between the first hole 82 and the second hole 83, and the second pin 87 is at a position straddling between the second hole 83 and the third hole 84. It will be arranged and will be in a connection state by these. Therefore, at this time, in the rocker arm 70, the input member 71 and the output member 76 swing integrally with the rotation of the rotary cam 10 around the respective base end portions, and the output shaft 78 at the distal end portion of the output member 76. Then, the valve 7 is pressed downward and driven. For this reason, in this connected state, intake is also performed to the cylinder 5 in which the variable valve mechanism 69 is installed, and the internal combustion engine is operated by the output from all the cylinders. At this time, the opening of the first hole 82 is closed by the end face of the first pin 86 having one end inserted into the first hole 82.

  According to the third embodiment, in addition to the same effects as the first embodiment, the following effects can be obtained. That is, since there is a variable valve mechanism 69 independently for each valve 7, the timing of changing the opening / closing amount of both valves 7 is shifted as needed, or the opening / closing amount of only one valve 7 is changed. It is also possible to change the design so that it changes.

  Further, since the rocker arm 70 is configured based on the four plates 70a, 70b, 70c, and 70d, the structure is simple.

  In the third embodiment, the following problems are also solved. That is, in the first embodiment, in addition to the connecting pin 45 composed of two pins, there is a closing pin 52 for closing the opening of the first hole 42 provided with the hydraulic chamber 53 in the hole, so that the number of parts increases. The rocker arm 20 becomes thicker in the width direction by the amount of the closing pin 52. Furthermore, since a coil spring-like spring 56 that is bulky in the width direction is interposed between the bottom surface of the third hole 44 and the second pin 47, this also causes the spring 56 and the third pin 47 to be interposed. The rocker arm 20 becomes thicker in the width direction by the thickness of the bottom surface of the hole 44. Then, thickening in the width direction is not particularly problematic as long as it is of the two-valve integrated type as in the first embodiment, but for each one valve 7 as in the third embodiment. When the rocker arms 70 are provided one by one, there is a problem because there is not enough space.

  In that respect, in the third embodiment, the closing pin is eliminated by closing the opening of the first hole 82 having the hydraulic chamber 93 in the hole with the connecting pin 85 and the input member 71 instead of the closing pin. The number of parts is reduced and space saving in the width direction is realized.

  Furthermore, space saving in the width direction can also be realized by making the third hole 84 a through-hole having no bottom surface portion and the spring 96 as a leaf spring extending in the length direction of the rocker arm 70 instead of a coil spring. Is realized.

  In addition, this invention is not limited to the structure of the said Examples 1-3, It can also change and actualize in the range which does not deviate from the meaning of invention, For example, like the following Modifications 1-3 It may be changed.

[Modification 1]
In the first embodiment, by providing a stopper or the like that limits the stroke at which the input member 21 and the output member 26 can be relatively displaced, as shown in FIGS. 7A and 7B, even in the disconnected state, The driving of the valve 7 may not be stopped completely, but the valve 7 may be driven with a lift amount smaller than that in the connected state.

[Modification 2]
As shown in FIG. 7 (c), an output member 99 having a swing center in the middle in the length direction, and an input member 98 extending from the swing center side of the output member 99 to the rear end side. The rocker arm 97 is provided, the input roller 23 and a switching mechanism (not shown) are provided at the rear end of the rocker arm 97, and the input roller 23 is pressed by the rotary cam 10 from below to be driven. .

[Modification 3]
In the third embodiment, instead of providing the variable valve mechanism 69 only for half of the plurality of cylinders 5, the two valves 7 of all the cylinders each having two intake valves 7 are provided. You may provide only for one each. In this case, when the connection is released, intake is performed into each cylinder only from the other valve 7 different from the valve 7 provided with the variable valve mechanism 69. Intake from 7 into each cylinder.

It is a perspective view which shows the variable valve mechanism of Example 1. FIG. In the first embodiment, (a) is a plan sectional view showing a state when an input member and an output member are in a disconnected state, and (b) is a plan sectional view showing a state in a connected state. In the first embodiment, (a) and (b) are side views showing the state when the input member and the output member are in the disconnected state, and (c) and (d) are side views showing the state when in the connected state. FIG. In Example 2, (a) is a plane sectional view which shows a mode when an input member and an output member are a connection cancellation | release state, (b) is a plane sectional view which shows a mode at the time of a connection state. In Example 3, (a) is a plane sectional view showing a state when an input member and an output member are in a disconnected state, and (b) is a plan sectional view showing a state in a connected state. In the third embodiment, (a) and (b) are side views showing the state when the input member and the output member are in the disconnected state, and (c) and (d) are the states when in the disconnected state. It is front sectional drawing shown. (A) And (b) is a side view which shows the variable valve mechanism of the modification 1, (c) is a side view which shows the variable valve mechanism of the modification 2. It is a perspective view which shows the variable valve mechanism of the prior art example 1. FIG. In the conventional example 1, (a) is a front sectional view showing a state when an inner arm and an outer arm are in a disconnected state, and (b) is a front sectional view showing a state in a connected state. It is a perspective view which shows the variable valve mechanism of the prior art example 2.

Explanation of symbols

7 Valve 9 Variable valve mechanism 10 Rotating cam 20 Rocker arm 21 Input member 23 Input roller 24 Shaft hole 26 Output member 40 Switching mechanism 45 Connection pin 53 Hydraulic chamber 54 Oil path 59 Variable valve mechanism 60 Switching mechanism 65 Connection pin 69 Variable operation Valve mechanism 70 Rocker arm 71 Input member 73 Input roller 74 Shaft hole 76 Output member 80 Switching mechanism 82 First hole (bottomed hole)
85 Connecting pin 93 Hydraulic chamber 94 Oil passage 96 Spring 97 Rocker arm 98 Input member 99 Output member

Claims (3)

A rocker arm including an input member having an input roller that rotatably contacts the rotating cam and an output member that contacts the valve; a connection state in which the input member and the output member are connected to each other so as not to be relatively displaceable; In a variable valve mechanism that includes a switching mechanism that switches between a connection release state that has been released, and changes the opening and closing amount of the valve by the switching,
The switching mechanism includes a connecting pin provided to be displaceable between a position straddling between the input member and the output member and a position not straddling in the axial direction on the axis of the input roller, and the connecting pin A hydraulic chamber provided inside the rocker arm that is hydraulically driven, and an oil passage that supplies the hydraulic pressure to the hydraulic chamber .
The variable valve mechanism according to claim 1, wherein the connecting pin is inserted into a shaft hole penetrating the shaft center of the input roller and pivotally supports the input roller . The hydraulic chamber has an opening formed in the output member so that the opening is recessed toward the input member. One end of the connection pin is inserted in the connected state, and one end is removed in the disconnected state. In the hole of the bottomed hole, the opening is closed by the inserted connecting pin in the connected state, and the opening is closed by the removed connecting pin and the input member in the disconnected state. Formed by
A closing pin that closes the opening without being removed from the bottomed hole is not interposed between the hydraulic chamber and the connecting pin in any of the connected state and the disconnected state. Item 1. The variable valve mechanism according to Item 1. 2. The switching mechanism includes a spring that urges the connecting pin in a direction against the hydraulic pressure, and the spring is a leaf spring that is attached to a side surface of the rocker arm and extends in the length direction of the rocker arm. Or the variable valve mechanism of 2.

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