RU2330164C2 - Engine valve train drive system - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: engine valve train drive system incorporates a rocking lever linked with the engine valve and furnished with a section adjoining the valve drive cam. The first connecting lever with its one end tied to the said rocking lever and its other end fitted to rotate on the engine housing.The second is connecting lever with its one end tied to the said rocking lever and its other end fitted to rotate on the offset movable support shaft. The said rocking lever is designed so that the section of linkage with the valve features a greater width along the valve drive cam rotation axis compared to that of the other section.

EFFECT: proposed design allows continuous variation of the valve travel, leave alone the smaller system overall sizes.

10 cl, 19 dwg

Description

FIELD OF THE INVENTION

The present invention relates to an engine valve drive system equipped with a variable valve lift mechanism that constantly changes a valve lift amount of an engine, namely, an intake valve or an exhaust valve,

State of the art

A valve drive system in which one end of the push rod is fixed to one end of the swing arm having a valve stop portion adjacent to the engine valve on the other end side, and a connecting mechanism is installed between the other end of the push rod and the valve actuator cam to continuously change the lift amount an engine valve, known from JP application No. 8-74534 (1).

However, in the valve drive mechanism disclosed in the patent document (1) described above, a relatively large space is required to accommodate the connecting mechanism and the push rod between the valve drive cam and the push rod, and therefore the valve drive system becomes large in size. In addition, the drive force from the cam side of the valve actuator is transmitted to the swing arm through the connecting mechanism and the pusher bar, and therefore it is difficult to say that the swing arm follows the cam of the valve actuator, namely, the ability to follow during opening and closing operations of the engine valves .

JP Application No. 2004-36560 proposes an engine valve drive system in which portions of one end of the first and second connecting arms are rotatably connected on a swing arm, and portions of the other end of the first connecting arm are rotatably mounted on the engine housing, and a portion of the other end the second connecting lever is biased by the drive means. According to the valve drive system, it is possible to make the valve drive system compact and it is also possible to provide excellent ability to follow the valve drive cam by directly transferring power from the valve drive cam to the swing arm.

Disclosure of invention

To reduce the size of the valve drive system, it is important to ensure a minimum width along the axis of rotation of the swing arm. However, if a single swing arm is used to open a pair of engine valves with the drive, the swing arm should preferably be configured such that the portion connecting to the valve provided on the swing arm for connecting to the motor valves has a maximum width to minimize swing arm width. This is due to the fact that the distance between the engine valves is essentially determined by the shape and size of the combustion chamber and, since the width of the connecting section with the valve, in turn, is determined by the distance between the engine valves.

The present invention was developed taking into account the above circumstances, and its purpose is to create a system for driving engine valves, which allows you to constantly change the amount of lift of the valve of the engine and which has a reduced size while making it possible to follow the opening / closing operations.

To achieve this, in accordance with a first aspect of the present invention, there is provided an engine valve drive system comprising a swing arm that has an abutment portion adjacent to a cam that abuts a valve actuator cam and which is interlocked and connected to an engine valve, a first connecting arm, one the end of which is rotatably connected with a swinging lever and the other end of which is rotatably connected with a fixed position of the motor housing, the second connecting a lever, one end of which is rotatably connected with a swinging lever and the other end of which is rotatably connected with a movable movable support shaft, and drive means connected to the movable support shaft, which allows shifting the position of the movable support shaft to constantly change the amount of lift of the engine valve, in which the swing arm having a connection section with a valve into which the pusher adjusting screws are screwed adjacent to a pair of engine valves so that they can be adjusted forward / backward position, and the first and second supporting sections to which the ends of the first and second connecting arms are rotatably connected, are formed so that the connection section with the valve has a greater width in the direction along the axis of rotation of the cam of the valve actuator than in the rest.

In addition to the first feature, in accordance with the second aspect of the present invention, the other end of the first connecting lever is rotatably mounted through the support shaft using the base walls provided in the motor housing, so that they are located on opposite sides of the other end of the first connecting lever. In this case, an insert is located between the other end of the first connecting lever and each of the walls of the base.

In addition to the second feature, in accordance with the third aspect of the present invention, the insert is a torsion spring provided between the engine housing and the swing arm, so that it springs the swing arm to the side where the contact portion of the cam abuts the cam of the valve actuator.

In addition to the first feature, in accordance with the fourth aspect of the present invention, the first support portion is formed to be substantially U-shaped so that a roller is inserted between its opposite sides, which is the abutment portion of the cam, and the roller is mounted with the possibility of rotation on the first supporting section.

In addition to the fourth feature, in accordance with the fifth aspect of the present invention, a pair of connecting sections is provided at one end of the first connecting lever, such that a first supporting portion of the swing arm is installed between the connecting sections. The connecting portions are rotatably connected to the first support portion via a connecting shaft. A roller is mounted on the axis of the first support section through the connecting shaft.

In addition to the first feature, in accordance with a sixth aspect of the present invention, the swing arm is formed so that the first and second support portions have the same width.

In addition to the first feature, in accordance with a seventh aspect of the present invention, the connecting holes through which the connecting shafts used to rotate one ends of the first and second connecting arms are inserted are formed in the first and second supporting positions so that they are adjacent to each other with the other in the directions of opening / closing the engine valves. The first and second supporting sections are connected together by means of a connecting wall at least partially located opposite the engine valves with respect to the tangent outer edges of the connecting holes next to the engine valves.

In addition to the seventh feature, in accordance with an eighth aspect of the present invention, a concave portion is formed in the connecting wall in a position opposite the other end of the second connecting arm when the other end of the second connecting arm is closest to the swing arm.

In addition to the seventh feature, in accordance with a ninth aspect of the present invention, a relief portion is formed on the connecting wall.

In addition to the first feature, in accordance with a tenth aspect of the present invention, the lightening portions are alternately formed on alternating molded surfaces of the swing arm.

Due to a first feature of the present invention, the lift amount of the engine valve can be continuously changed by constantly shifting the movable support shaft. Among other things, one end of each of the first and second connecting arms is rotatably connected directly to the swing arm. This reduces the size of the space in which the connecting levers are installed and the size of the valve drive system. In addition, power from the cam of the valve actuator is directly transmitted to the portion adjacent to the cam of the swing arm. This provides an exceptional ability to follow the swing arm to the cam of the valve actuator. In addition, the swing arm opens a pair of motor valves with the drive. The swinging lever has a connection section with a valve, on which the adjusting screws of the pusher are screwed adjacent to the pair of engine valves, which allows you to adjust their position forward / backward, and the first and second supporting sections, to which the first and second connecting levers are rotatably connected. The swing arm is formed so that the width of the connection section with the valve in the direction along the axis of rotation of the cam of the valve actuator is greater than the rest of it. This minimizes the width of the swing arm in the direction along the axis of rotation of the cam of the valve actuator. It also reduces the size of the valve drive system.

When using the second feature of the present invention, the insert is placed between the other end of the first connecting lever and each of the base walls provided on the motor housing, so that it is located on opposite sides of the other end of the first connecting lever. The choice of insert allows you to install the first connecting lever so that the insert allows you to absorb the size tolerance between the first connecting lever and the base wall.

Due to a third aspect of the present invention, a torsion spring that presses the swing arm in a direction in which the abutment portion of the cam abuts the cam of the valve actuator acts as an insert. This makes it possible to absorb the dimensional tolerance. It is also possible to provide emphasis on the abutment portion of the cam in the cam of the valve actuator. This improves the accuracy of valve lift control.

Due to a fourth aspect of the present invention, a first support portion formed to be substantially U-shaped holds the roller rotatably. This allows you to reduce the size of the entire swing arm, including the roller.

Due to the fifth aspect of the present invention, a common connecting shaft is used to rotatably connect one end of the first connecting lever to the first supporting portion of the base, which allows axial mounting of the roller on the first supporting portion. This allows to reduce the number of required parts and, thus, further reduce the size of the valve drive system.

Due to the sixth feature of the present invention, the first and second supporting sections have the same width. This reduces the size of the swing arm while simplifying the shape.

Due to a seventh aspect of the present invention, the first and second support portions of the swing arm are connected together by means of a connecting wall at least partially mounted opposite the engine valves with respect to the tangent outer edges of the pair of connection holes adjacent to the engine valves formed on the support portions. This allows you to improve the stiffness of the first and second supporting sections.

Due to the eighth aspect of the present invention, the other end of the second connecting arm can be offset as close as possible to the swing arm. This allows you to set the maximum valve lift for the engine, reducing the size of the valve drive system.

Due to the ninth aspect of the present invention, it becomes possible to prevent the increase in the weight of the swing arm while improving stiffness using the connecting wall.

Due to a tenth aspect of the present invention, the lightening portions are alternately formed on alternating surfaces of the swing arm. This reduces the weight of the swing arm. The lightening portions are formed simultaneously with the formation of the swing arm, and the lightening portions adjacent to each other have slope angles in opposite directions. Accordingly, the inner surfaces of adjacent lightening portions are inclined in one direction. Therefore, the wall portions formed on the rocker arm between adjacent lightening portions have substantially uniform, uniform thickness. Wall sections of substantially equal thickness maintain the rigidity of the swing arm.

Brief Description of the Drawings

Figure 1 shows a side view with a section of the engine in accordance with the first embodiment of the present invention, along the line 1-1, indicated in figure 2. (Option 1)

Figure 2 shows a sectional view along the line 2-2, indicated in figure 1. (Option 1)

Figure 3 shows a sectional view along the line 3-3, indicated in figure 2. (Option 1)

Figure 4 shows a side view of a variable lift mechanism. (Option 1)

Figure 5 shows a perspective view with an exploded view of the details of the variable lift mechanism. (Option 1)

Figure 6 shows a sectional view with an increase along the line 6-6, indicated in figure 4. (Option 1)

In Fig.7 shows a view of the part shown by arrow 7, indicated in Fig.3. (Option 1)

On figa shows an explanatory diagram representing the operation of the variable lift mechanism, performed with a high degree of valve lift. (Option 1)

On figv shows an explanatory diagram representing the operation of the variable lift mechanism, performed with a small degree of valve lift. (Option 1)

FIG. 9 is a graph showing a lift curve of an engine valve. (Option 1)

Figure 10 shows a view with an increase in the essential part of figure 3. (Option 1)

11 is a graph showing the relationship between the angle of rotation of the control lever and the angle of rotation of the sensor lever. (Option 1)

FIG. 12 is a side view of a sectional view of an engine according to a second embodiment of the present invention along line 12-12 of FIG. 13. (Option 2)

On Fig shows a view of the part indicated by arrow 13 in Fig. 12. (Option 2)

On Fig shows a sectional view along the line 14-14, indicated in Fig.13. (Option 2)

On Fig shows a view with an increase in a substantial part of Fig. (Option 2)

On Fig shows a bottom view of the intake swing arm along the direction shown by arrow 16 in Fig. 15. (Option 2)

On Fig shows a view in section along the line 17-17, indicated in Fig.15. (Option 2)

On Fig shows a perspective view of a variable lift mechanism. (Option 2)

On Fig shows a view in section along the line 19-19, indicated in Fig.15. (Option 2)

The implementation of the invention

A method of performing the present invention will be described below by way of example embodiments, with reference to the accompanying drawings.

Option 1

1-11 show a first embodiment of the present invention.

According to figure 1, the housing 10 of the engine of a linear multi-cylinder engine E contains inside the cylinder block 12 with holes 11 for the cylinders, a cylinder head 14 connected to the upper side of the cylinder block 12, and a cylinder head cover 16 fixed to the upper side of the cylinder head 14. Pistons 13 are slidably mounted in cylinder bores 11. The combustion chambers 15, facing the upper parts of the pistons 13, are formed between the cylinder block 12 and the cylinder head 14.

The cylinder head 14 is equipped with inlet channels 17 and outlet channels 18, which can be connected to the combustion chambers 15. The inlet channels 17 are opened and closed with a pair of inlet valves 19, 19, which are engine valves, while the outlet channels 18 are opened and closed with a pair of exhaust valves 20, 20. Each inlet valve 19 has a stem 19a installed with the possibility of sliding in the valve guide 21 provided in the cylinder head 14, and is spring-loaded in the closing direction of the valve by means of a valve spring 24 mounted between the spring socket 22 provided on the upper end of the stem 19a and the socket 23 Ruzyne abutting on the cylinder head 14. Each exhaust valve 20 has a stem 20a slidably mounted in the valve guide 25 provided in the cylinder head 14 and is spring loaded in the closing direction of the valve by a valve spring 28 mounted between the spring receptacle 26 provided on the upper end of the stem 20a, and socket 27 for the spring abutting against the cylinder head 14.

As also shown in FIG. 2, the cylinder head 14 integrally comprises a holder 44, the holding walls 44a of which are located on opposite sides of each cylinder. The covers 45 and 47 are firmly connected to each holding wall 44a to form the intake cam holder 46 and the exhaust cam holder 48 together. As a result, the intake camshaft 31 is rotatably mounted on the intake cam holders 46, while the exhaust camshaft 32 is rotatably mounted on the exhaust cam holders 48. The intake valve 19 is driven by an intake camshaft 31 through a variable valve lift mechanism 33. The exhaust valve 20 is driven by an exhaust camshaft 32 through a variable valve timing / lift means 34.

The variable synchronization / lift means 34 that drives the exhaust valves 20 is well known and will only be described here schematically. A pair of low speed swing levers 36, 36 and one high speed swing arm 37 are rotatably mounted at their first ends on the shaft 35 of the exhaust swing arm, which is mounted by the walls 44a of the holder of the holders of the exhaust cam 43. Two low-speed swing levers 36, 36 on the exhaust camshaft 32 abut against a roller 40 mounted axially in the intermediate part of the high-speed swing arm 37. Pusher adjusting screws 42, which abut the upper ends 20a of the exhaust valve rods 20, are screwed at the second ends of the low-speed swinging levers 36 so that it is possible to adjust their position forward / backward.

The low speed swing arms 36, 36 and the high speed swing arm 37 can be connected and can be disconnected under hydraulic control. When the engine E is operating at low speed, if the low speed swing arms 36, 36 and the high speed swing arm 37 are disconnected, the low speed swing arms 36, 36 are driven by the corresponding low speed cams 39, 39, and therefore the exhaust valves 20, 20 open and close with low valve lift and low opening angle. On the other hand, when the engine E is operating at high speed, if the low speed swing arms 36, 36 and the high speed swing arm 37 are connected, the high speed swing arm 37 is driven by the corresponding high speed cam 41, and therefore the exhaust valves 20, 20 open and close with a high valve lift and a large opening angle with the help of low-speed swing levers 36 connected to the high-speed swing lever 37. Thus, the lift of the valve and the moments of opening / closing yvaniya exhaust valves 20, 20 is controlled at two levels by using 34 alternating opening / closing / valve lift.

The low speed swing arms 36, 36 and the high speed swing arm 37 can be connected and disconnected under hydraulic control. When engine E is running at low speed, if the low speed swing arms 36, 36 and the high speed swing arm 37 are disconnected, the low speed swing arms 36.36 are driven by the corresponding low speed cams 39, 39. Therefore, the exhaust valves 20, 20 open and close with a small degree valve lift and with a small opening angle. On the other hand, when the engine E is operating at high speed, if the low speed swing arms 36, 36 and the high speed swing arm 37 are connected, the high speed swing arm 37 is driven by the corresponding high speed cam 41. Therefore, the exhaust valves 20, 20 open and close with a large the degree of valve lift and with a large opening angle by low-speed swinging levers 36, 36 connected to the high-speed swinging lever 37. Thus, the degree of valve lift and moments cf the abutment of the exhaust valves 20, 20 is controlled at two levels alternately by means of a valve opening / closing / lifting means 34.

Next, the construction of the variable lift mechanism 33 will be described with reference to FIGS. The variable-lift mechanism 33 comprises an inlet swing arm 63 having a roller 65 that functions as a cam-abutment portion that abuts against an intake valve actuator cam 69 provided on the intake camshaft 31, a first connecting arm 61, the first end of which is rotatably connected to an inlet swing arm 63 and a second end of which is rotatably connected with a fixed position on the engine housing 10, and a second connecting arm 62, the first end of which is connected to POSSIBILITY rotation with the intake rocker arm 63 and a second end which is rotatably coupled to the displaceable movable support shaft 68a.

The inlet swing arm 63 comprises, at its first end, a valve connection portion 63 a on which the pusher adjusting screws 70, 70 are screwed so that they allow for forward / backward adjustment of the screws, while the pusher adjusting screws 70, 70 abut against the upper ends the rods 19a of the pair of intake valves 19 from above. The second end of the inlet swing arm 63 is formed to give it a generally U-shape that opens in a direction opposite to the inlet valves 19. The second end of the inlet swing arm 63 comprises a first support portion 63b to which the first end of the first connecting a lever 61 and a second support portion 63c, to which the first end of the second connecting lever 61 is rotatably connected; a second support portion 63c is located below the first support portion 63b. In addition, the roller 65 is located so that it is installed between the linear sections of the generally U-shaped first support portion 63b; the roller 65 performs the function of a portion adjacent to the cam mounted in rolling contact with the cam 69 of the intake camshaft intake valve 31. The roller 65 is axially mounted on the first support portion 63b coaxially with the connecting portion of the first end of the first connecting arm 61.

In addition, the intake swing arm 63 is formed so that the valve connection portion 63 a has a width greater than the rest in the direction along the rotation axis of the intake valve actuator cam 69. The first and second support portions 63b and 63v are formed so that they have the same width.

The first connecting arm 61 is formed to be substantially U-shaped, and an inlet swing arm 63 is mounted between the pair of first connecting portions 61a, 61a, with a cylindrical fixed support portion 61b and a pair of lever portions 61c, 61c that connect the first connecting sections 61a, 61a and a fixed support section 61b.

The first connecting portions 61a, 61a and the first end of the first connecting lever 61 are rotatably connected to the first supporting portion 63b of the intake swing arm 63 through a cylindrical first connecting shaft 64 fixedly inserted into the first connecting hole 49 formed on the first supporting portion 63b of the intake swing arm 63. The roller 65 is also axially mounted on the first bearing portion 63b through the needle bearing 60 and the first connecting shaft 64. In addition, the outer flange of this part of the first bearing section 63b, which is located opposite the intake camshaft 31, overlaps the outer flanges of the first connecting portions 61a, 61a of the first connecting arm 61 in a side view; this forms an arcuate shape around the axis of the first connecting shaft 64.

The second connecting arm 62 is located below the first connecting arm 61. The second connecting arm 62 has a first connecting portion 62a at its first end and a movable supporting portion 62b at its second end. A second connecting portion 62a is mounted between the linear portions of the generally U-shaped second supporting portion 63b. The second support portion 63c comprises not only a first connection hole 49 of the first support portion 63b, but also a second connection hole 50 located adjacent to the first connection hole 49 in a direction in which both inlet valves 19 open and close, that is, in the vertical direction . The second connecting portion 62a is rotatably connected to the second supporting portion 63c via a second connecting shaft 66 fixedly inserted into the second connecting hole 50.

The first end of the intake swing arm 63 having a roller 65 located above the second end adjacent to the intake valve actuator cam 69 is interlocked and connected to the pair of intake valves 19, the first connecting portions 61a, 61a provided at the first end of the upper first connecting arm 61, and the second connecting portion 62a provided at the first end of the second connecting lever 62 located below the first connecting lever 61 is mounted vertically, in parallel and mutually connected with the possibility of ascheniya to the second arm of the intake rocker arm 63.

The inlet swing arm 63 is integrally mounted with a pair of connecting walls 63d that connect together, in general, the U-shaped first and second support portions 63b and 63c. The connecting walls 63d are formed so that they join together the first and second supporting sections 63b and 63c, while the connecting walls 63d are at least partially opposite the inlet valves 19 with respect to the tangent L, which is in contact with the outer walls of the first and second connecting holes 49 and 50 on the side of both inlet valves 19.

Concave portions 51 are formed in the connecting walls 63d opposite the movable support shaft 68a, where the movable support portion 62b at the second end of the second connecting arm 62 is closest to the inlet swing arm 63. In addition, facilitating portions 52 are formed on the connecting walls 63d with a recess from the outer surface to the inner surface of each wall.

The fixed support portion 61b at the second end of the first connecting arm 61 is rotatably mounted via the fixed support shaft 67 on the base walls 44a located on opposite sides of the fixed support portion 61b so that they constitute the lower part of the intake cam holder 46 provided on the engine housing 10 . A fixed support shaft 67 is fixedly mounted on opposite support walls 44a.

In particular, as shown in FIG. 6, a pair of support bulges 53, 53 protrude, being formed as a single piece, from the base walls 44a, extending in the axial direction to the fixed support portion 61b of the first connecting arm 61. On each of the support bulges 53, a shaft portion 53a of a smaller diameter that may come into contact with sliding with opposite ends of the fixed support portion 61b, and a stepped portion 53b located opposite and at a distance from the opposite ends s side fixed support portions 61b, so that it surrounds the proximal end portion 53a with a smaller diameter shaft. The fixed support shaft 67 is fixedly mounted using the support bulges 53, so that it coaxially extends to sections 53a of the shaft with a smaller diameter.

Both inlet valves 19 are spring-loaded with valve springs 24 in the closing direction of the valve. When the inlet swing arm 63 drives in the opening direction of the valve, both inlet valves 19 are spring-loaded in the closing direction of the valve using the valve springs 24, which ensures that the roller 65 of the inlet swing arm 63 is in contact with the inlet valve actuator cam 69. However, when the intake valves 19 are closed, the pressing force exerted by the valve spring 24 does not act on the intake swing arm 63. Consequently, the roller 65 can deviate from the intake valve actuator cam 69, which reduces the accuracy of controlling the valve lift amount when the inlet valves 19 need to be opened slightly. In addition, a torsion spring 54 is provided separately from the valve spring 24; a torsion spring 54 is located between each of the opposite surfaces of the fixed support portion 61b and the second end of the first connecting arm 61 and the support bulges 53 protruding from each of the base walls 44a located on opposite sides of the fixed support portion 61b. A torsion spring 54 springs the intake swing arm 63 in the direction in which the roller 65 is adjacent to the intake valve actuator cam 69.

The torsion spring 54 is installed so that it surrounds the fixed support shaft 67 through the shaft portion 53a of the smaller diameter of the supporting convex 53. The torsion spring 54 is installed between the engine housing 10 and the inlet swing arm 63. In other words, the first end of the torsion spring 54 surrounding the shaft portion 53a of smaller diameter, connected to a fixing pin 55 mounted on a portion 53b of the step of the support convexity 53. The second end of the torsion spring 54, inserted into the hollow first connecting shaft 64 and connected to it, works together with the inlet swing arm 63.

The fixed support portion 61b at the second end of the first connecting arm 61 is formed in the form of a cylinder so that its outer contour is placed sideways inside the outer contour of each torsion spring 54, while the spring that springs the swing arm is wound like a coil spring. Many, for example, a pair of protruding sections 56 and 57 are provided at a distance from each other in the circumferential direction, so that they protrude at opposite ends of the fixed support section 61b in its axial direction. The protruding sections 56 and 57 are designed to hold the torsion springs 54 so that they do not fall on the fixed support section 61b. The protruding sections 56 and 57 are located outside the range of operation of the second connecting lever 62.

Oil spray nozzles 58 are rigidly mounted on the engine housing 10 as an oil supply means for supplying oil to the upper one of the first and second connecting shafts 64 and 66 located on the second end of the inlet swing arm 63 in parallel so that they connect the first the connecting portions 61a and the second connecting portions 62a together, which are provided at the first ends of the first and second connecting levers 61 and 62. In the present embodiment, the oil spray nozzles 58 are TCRs are mounted on holders 45 covers the air intake cam 46 provided in the engine body 10, the oil supply to the first coupling shaft 64, one of the first and second connecting shafts 64 and 66.

In addition, a first support portion 63b is provided on an upper portion of a second end of the intake swing arm 63; moreover, the first support portion 63b is formed by giving it a generally U-shape, which allows the roller 65 to be installed between its linear sections. The first connecting portions 61a of the first connecting arm 61 are rotatably connected to the first supporting portion 63b through a first connecting shaft 64, on which the roller 65 is mounted axially. Oil spray nozzles 58 are located on the covers 45 for supplying oil to the respective surfaces of the first connecting portions 61a of the first connecting a lever 61 and a first support portion 63b.

The crank element 68 comprises a movable support shaft 68a that rotatably supports the movable support portion 62b provided at the second end of the second connecting arm 62. The crank element 68 is formed at opposite ends of the connecting plate 68b located in a plane parallel to the plane in which operates the second connecting lever 62, and at right angles so that the movable support shaft 68a and the support shaft 68c protrude in opposite directions. The support shaft 68c is rotatably mounted in the support hole 16a formed in the cover 16 of the head of the engine housing 10.

When the intake swing arm 63 is in the raised position shown in FIG. 4, that is, when the intake valves 19 are closed, the spindle 68c of the crank member 68 is mounted coaxially with the axis C of the second connecting shaft 66, which rotates lower part of the intake swing arm 63 (see FIG. 5). Therefore, when the crank element 68 swings around the axis of the spindle 68c, the movable support shaft 68a moves along the arc A (see FIG. 4), centered on the spindle 68c.

The spindle 68c of the crank element 68 projects through the support hole 16a in the cylinder head cover 16. The control lever 71 is mounted on the tip of the spindle 68c and is driven by a drive motor 72 mounted on the outer wall of the cylinder head 14 and functions as a drive means. That is, the nut member 74 is engaged with a threaded shaft 73 that rotates by the drive motor 72. The first end of the link 76 is rotatably mounted on the nut member 74 via a pin 75. Its second end is connected to the control lever 71 via the pins 77, 77. Therefore, when the drive 72 motor 72 is turned on, the nut member 74 moves along the rotary threaded shaft 73. Then, the crank element 68 swings around the spindle 68c under the action of the control lever 71 connected to the nut element 74 through the connecting link 76. After that, the movable support shaft 68a moves between the position shown in Fig. 8A, and the position shown in figv.

A rotation angle sensor 80, such as a rotation encoder, is mounted on the surface of the outer wall of the cylinder head cover 16. The first end of the sensor lever 81 is fixed to the tip of the shaft 80a of the rotation angle sensor 80. A guide groove 82 is formed on the control lever 71 so that it extends linearly along its length. A connecting shaft 83 mounted on the second end of the sensor lever 81 is slidably mounted in the guide groove 82.

The threaded shaft 73, the nut element 74, the pin 75, the connecting link 76, the pins 77, 77, the control lever 71, the rotation angle sensor 80, the sensor lever 81 and the connecting shaft 83 are mounted on wall sections 14a and 16b protruding on the flanges of the cylinder block 14 and covers 16 cylinder heads. A cover 78 that covers the end sides of the wall portions 14a and 16b is secured to the wall portions 14a and 16b with bolts 79.

In the variable valve lift mechanism 33, when the control lever 71 is rotated counterclockwise by the drive motor 72 from the position indicated by the continuous line of FIG. 3, the crank element 68 (see FIG. 5) connected to the lever 71 control, rotates counterclockwise. The movable support shaft 68a of the crank member 68 is raised as shown in FIG. 8A. When the cam of the intake valve actuator 69 mounted on the intake camshaft 31 pushes the roller 65 in this state, the four-link connecting the fixed support shaft 67, the first connection shaft 64, the second connection shaft 68 and the movable support shaft 68a are deformed. As a result, the intake swing arm 63 tilts down from the position shown by the dashed line to the position shown by the solid line. Then, the adjusting screws 70, 70 of the pusher push the inlet valve stems 19a of the inlet 19. As a result, the inlet valves 19 open with a high valve lift.

When the control lever 71 is rotated to the position shown by the solid line in FIG. 3 by the drive motor 72, the crank member 68 connected to the control lever 71 is rotated in a clockwise direction. The movable support shaft 68a of the crank member 68 is lowered, as shown in FIG. When the intake valve actuator cam 69 mounted on the intake camshaft 31 pushes the roller 65 in this position, the four link is deformed. As a result, the intake swing arm 63 tilts down from the position shown by the dashed line to the position shown by the solid line. Then, the adjusting screws 70, 70 of the pusher push the stems 19a of the intake valves 19. The intake valves 19 as a result open with a small amount of valve lift.

Fig. 9 is a diagram showing a valve lift curve for the intake valve 19. An opening angle with a high valve lift in accordance with Fig. 8A will be the same as an opening angle with a small valve lift in accordance with Fig. 8B, and only the valve lift amount is changed. Thus, the variable valve lift mechanism 33 can freely change only the valve lift amount, without changing the opening angle of the intake valves 19.

When changing the valve lift for the intake valves 19 by tilting the crank element 68 using the drive motor 72, it is necessary to detect the lift amount, i.e., the angle of rotation of the spindle 68c of the crank element 68, and transmit this data via the feedback circuit for use when driving 72 drive motor. To this end, the rotation angle sensor 80 detects the rotation angle of the spindle 68c of the crank element 68, detects the rotation angle sensor 80. To easily detect the rotation angle of the spindle 68c of the crank element 68, the rotation angle sensor 80 can be connected directly to the spindle 68c. However, since the intake efficiency varies significantly even with a small change in the valve lift in the region of small valve lift, it is necessary to accurately detect the angle of rotation of the spindle 68c of the crank element 68 and transmit this data via the feedback circuit for use in controlling the drive motor 72. On the other hand, in the region of high lift, since the intake efficiency does not change significantly, even with a slight change in the lift of the valve, high accuracy is not required for detecting the angle of rotation.

The position of the control lever 71, indicated by the solid line in FIG. 10, corresponds to a low lift region. The position of the control lever 71, indicated by the dashed line in the counterclockwise direction from the region of small rise, corresponds to the position of the high rise. In the low-lift region, since the connecting shaft 83 of the sensor lever 81 fixed to the shaft 80a of the rotation angle sensor 80 is connected to the tip side (the side further from the axis C) of the guide groove 82 of the control lever 71, even a slight tilt of the control lever 71 leads to significant tilt of the lever 81 of the sensor. This enhances the ratio of the angle of rotation of the shaft 80a of the sensor with respect to the angle of rotation of the crank element 68. Thus, the resolution of the sensor 80 of the angle of rotation is improved, which allows high-precision detection of the angle of rotation of the crank element 68.

On the other hand, in the high valve lift region in which the control lever 71 has tilted to the position indicated by the dotted line, since the connecting shaft 83 of the sensor lever 81 fixed to the shaft 80a of the rotation angle sensor 80 is connected to the base side (the side closer to axis C) of the guide groove 82 of the control lever 71, even a large inclination of the control lever 71 leads to a slight inclination of the sensor lever 81. This reduces the ratio of the angle of rotation of the sensor shaft 80a with respect to the angle of rotation of the crank element 68. As a result, the accuracy of detecting the angle of rotation of the crank element 68 is reduced compared with the case of a small valve lift.

As can be clearly seen from the graph shown in FIG. 11, when the angle of rotation of the control lever 71 increases from a state of small valve lift to a state of large valve lift, the detection accuracy will be initially high. This is due to the high rate of increase in the angle of the lever 81 of the sensor. However, the rate of increase in the angle gradually decreases, leading to a decrease in the accuracy of detection.

Thus, without the use of an expensive rotation angle sensor with high detection accuracy, by connecting the lever 81 of the rotation angle sensor 80, which is connected by the guide groove 82 of the control lever 71, it has become possible to provide high detection accuracy in a low lift state in which such detection accuracy is required. This contributes to lower costs.

In such an arrangement, since one end (an end located closer to the spindle 68c) of the control lever 71 and one end (an end located closer to the rotation angle sensor 80) of the sensor lever 81 are adjacent to each other. In addition, a guide groove 82 is formed at the end of the control lever 71. Accordingly, the sensor lever 81 may be compact with a reduced length. In particular, the formation of the guide groove 82 at the end of the control lever 71 reduces the distance from the axis C, as well as the amount of movement in the direction of the outer circumference of the guide groove 82. However, the length of the sensor lever 81 also decreases, providing a sufficient angle of rotation of the sensor lever 81. This ensures accurate detection of the angle of rotation of the sensor 80.

Next, the operation of the first embodiment will be described. In the variable lift mechanism 33, which constantly changes the lift amount of the intake valves 19, the first connecting portions 61a, 61a and the second connecting portion 62a, mounted on the first ends of the first connecting lever 61 and the second connecting lever 62, respectively, are mounted in parallel and are relative turning with the second end of the intake swing arm 63, the valve connecting portion 63a of which is locked and connected to the pair of intake valves 19 at the first end. The fixed support portion 61b and the second end of the first connecting arm 61 are rotatably mounted on the fixed support shaft 67 of the motor housing 10. The movable support portion 62b at the second end of the second connecting arm 62 is rotatably mounted on the movable movable support shaft 68a.

Thus, by constantly changing the position of the movable support shaft 68a, it is possible to continuously change the lift amount of the intake valves 19. Furthermore, since the first ends of the first and second connecting arms 61 and 62 are rotatably connected directly to the intake swing arm 63, it becomes possible to reduce the space , in which the connecting levers 61 and 62 are installed. This reduces the size of the valve drive system. In addition, since power is transmitted directly from the intake valve actuator cam 69 to the inlet swing arm roller 65, it becomes possible to correctly follow the intake valve actuator cam 69. In addition, the swing arm 63 and the first and second connecting arms 61 and 62 can be installed at approximately the same location along the axis of the intake camshaft 31. This makes it possible to reduce the size of the valve drive system along the axis of the intake camshaft 31.

In addition, on the intake swing arm 63, which has a valve connection portion 73a into which pusher adjusting screws 70 are screwed adjacent to the pair of intake valves 19 so that their forward / backward position can be adjusted and the first and second support portions 63b and 63 c, to which the first ends of the first and second connecting arms 61 and 62 are rotatably connected, the valve connecting portion 63 a has a larger width than the rest in the direction along the axis of rotation of the intake valve actuator cam 69. The width of the intake swing arm 63 can thus be reduced in the direction along the axis of rotation of the intake cam 69. It also reduces the size of the valve drive system. In addition, the intake swing arm 63 is formed so that the first and second support portions 63b and 63c have the same width. Thus, it is possible to make the intake swing arm 63 compact, while simplifying the shape of this component.

In addition, the first support portion 63b provided on the intake swing arm 63 is formed to be substantially U-shaped so that a roller 65 is mounted between its linear portions. The roller 65 is rotatably mounted on the first support portion 63b . Accordingly, the entire intake swing arm 63, including the roller 65, can be compact. In addition, the paired first connecting portions 61a between which the first supporting portions 63b are mounted are provided at the first end of the first connecting arm 61. Both first connecting portions 61a are rotatably connected to the first supporting portion 63b through the first connecting shaft 64. The roller 65 is held first the supporting portion 63b through the first connecting shaft 64. Therefore, the common first connecting shaft 64 is used to rotatably connect the first end of the first connecting lever 61 with the first support portion 63b, which provides for the first support portion 63b the ability to hold the roller 65. This allows to reduce the number of required parts and the size of the valve drive system.

The first and second connecting holes 49 and 50 are formed on the first and second support portions 63b and 63c of the intake swing arm 63, so that they are adjacent to each other in the direction in which the intake valves 19 open and close; wherein the first and second connecting shafts 64 and 66, to which the first ends of the first and second connecting levers 61 and 62 are rotatably connected, are inserted into the first and second connecting holes 49 and 50. The first and second supporting sections 63b and 63c are connected together with by connecting walls 63d at least partially opposite both inlet valves 19 with respect to a tangent L to the outer edges of the first and second connecting holes 49 and 50 on the side of both inlet valves 19. This makes it possible to improve the gesture awn first and second support portions 63b and 63c.

In addition, concave portions 51 are formed on the connecting walls 63d so that they are mounted opposite the second connecting portion 62a when the second connecting portion 62a at the second end of the second connecting arm 62 is closest to the inlet swing arm 63. Accordingly, the second the connecting portion 62a of the second connecting arm 62 can be shifted to a position where it is located as close as possible to the inlet swing arm 63. This allows you to set the maximum amount of lift intake valve 19 by decreasing the size of the drive system of valves.

In addition, facilitating portions 52 are formed on the connecting walls 63d. This makes it possible to reduce the weight of the inlet swing arm 63, while at the same time improving stiffness by using the connecting walls 63d.

Oil spray nozzles 58 are rigidly mounted on the engine housing 10 to supply oil to the first connecting shaft 64, the upper one of the first and second connecting shafts 64 and 66, which connect the first ends of the first and second connecting levers 61 and 62 with the inlet swing arm 63. Oil penetrating between the inlet swing arm 63 and the first connecting lever 61, the upper one of the first and second connecting arms 61 and 62, flows downward, penetrating between the second connecting lever 62 and the inlet swing arm 63. Therefore, a simple lubrication system with a reduced number of parts can be used to lubricate both the connecting portions of the intake swing arm 63 with the first and second connecting arms 61 and 62. This ensures a smooth operation of the valves.

In addition, a first connecting portion 63b, formed generally to be U-shaped so that the roller 65 can be mounted between its linear portions, is provided in the intake swing arm 63. The first connecting portion 61a is at the first end of the first the connecting lever 61 is rotatably connected to the first support portion 63b through the first connecting shaft 64 on which the roller 65 is mounted. Oil spray nozzles 58 are located on the motor housing 10 for supplying oil to the mating surfaces the first link arm 61 and the first support portion 63b. In this way, it is possible to lubricate even the abutting portion of the roller 65.

In addition, the oil spray nozzles 58 are located on the covers 45 of the inlet cam holders 46 provided on the engine housing 10 for rotationally mounting the intake camshaft 31, on which the valve actuator inlet cam 69 is provided. Therefore, by using an oil channel for lubrication between the inlet camshaft 31 and the inlet cam holders 46, it is possible to supply a sufficient amount of oil through the oil spray nozzles 58 at a sufficiently high pressure.

The inlet valves 19 are spring-loaded with valve springs 24 in the direction of valve opening. However, the inlet swing arm 63 is spring loaded with torsion springs 54, which differ from the valve springs 24 in the direction in which the roller 65 is pressed against the intake valve actuator cam 69. Accordingly, even when the intake valves 19 are closed, the roller 65 on the intake swing arm 63 does not deviate from the intake valve actuator cam 69. This improves the control accuracy of the valve lift when the intake valves 19 are opened slightly.

In addition, the torsion springs 54 are helical torsion springs surrounding the fixed support shaft 67. This reduces the space in which the torsion springs 58 are installed. Therefore, the size of the valve drive system can be reduced.

In addition, a pair of support bumps 53, 53 on which a fixed support shaft 67 is mounted are provided on the base walls 44a of the intake cam holders 46 on the engine housing 10, so that a second end of the first connecting arm 61 is installed between the bumps. Torsion springs 54 are located between each base wall 44a and the second end of the first connecting lever 61 on the engine housing 10, so that they surround the support bulges 53, 53. Therefore, it is possible to easily install the first connecting lever 61 so that the torsion bar The loaded springs 54 will absorb a dimensional tolerance between the first connecting arm 61 and the base walls 44a. In addition, the torsion springs 54 can be located in a smaller space, which eliminates the negative impact of compression of the torsion springs 54 on the fixed support shaft 67 when using a pair of support bulges 53, 53 to control the movement of the fixed support section 61b at the second end of the first connecting arm 61.

A cylindrical fixed support portion 61b is located at the second end of the first connecting arm 61; the outer contour of the fixed support portion 61b is located inside from the outer contour of each torsion spring 54 in a side view. The fixed support portion 61b is rotatably mounted on the fixed support shaft 67. However, a plurality of protruding portions 56, 57 are provided at the axial opposite ends of the fixed support portion 61b at intervals along the circumference so that they protrude at opposite ends with respect to the axis; however, the protruding sections 56, 57 do not allow the torsion springs 54 to fall on a fixed support section 61b. Therefore, it is possible to prevent the lowering of the torsion springs 54, as described above, while preventing an increase in the size of the fixed support portion 61b. Thus, the stiffness of the support of the fixed support portion 61b can be improved.

In addition, the protruding portions 56, 57 are located outside the operating range of the second connecting arm 62. Accordingly, even though the protruding portions 56, 57 are provided on the fixed support portion 61b, sufficient space can be provided for the second connecting arm 62 for work.

In addition, the variable lift mechanism 33 is equipped with crank elements 68, consisting of a movable support shaft 68a and a support shaft 68c, the axis of which is parallel to the movable support shaft 68a; wherein the movable support shaft 68a and the support shaft 68c protrude at opposite ends of the connecting plate 68b. The support shaft 68c is rotatably mounted using the head cover 16 on the engine housing 10. Accordingly, rotation of the crank element 68 about the axis of the support shaft 68c makes it easy to move the movable support shaft 68a. This simplifies the mechanism in which the drive motor 72 is used to bias the movable support shaft 68a.

Option 2

12-19 show a second embodiment of the present invention. In these drawings, parts corresponding to parts used in the first embodiment are denoted by the same reference numerals and symbols.

First of all, as shown in FIGS. 12-14, the upper holders 98, which function as the base walls, are fixed to the cylinder head 14 in a row on opposite sides of each cylinder. The covers 99, 100 are fixed to the upper holders 98 from above so that the inlet cam holders 101 and the exhaust cam holders 102 are jointly formed. The intake camshaft 31 is rotatably mounted between the upper holder 98 and the covers 99, which together constitute the intake cam holders 101. The exhaust cam holder 103 is rotatably mounted between the upper holders 98 and the covers 100 constituting the exhaust cam holders 102.

The exhaust swing shaft 104 mounted on the upper holders 98 holds the first ends of the exhaust swing arms 105 corresponding to the corresponding exhaust valves 20 so that its first ends can swing. A pair of pusher adjusting screws 42 are screwed at the second end of each of the exhaust swing arms 105 so that their forward / backward position can be adjusted. The pusher adjusting screws 42 abut against the upper ends of the exhaust valve rods 20a 20. The exhaust swing arm 105 comprises a shaft 108 in its intermediate portion. The shaft 108 extends parallel to the exhaust swing shaft 104. The roller 106 is mounted on the exhaust swing arm 105 using a roller bearing 109 located between the roller 106 and the shaft 108; the roller 106 is in rolling contact with the cam 107 of the exhaust valve actuator, which is mounted on the shaft 103 of the exhaust cam.

In addition, the swing portion of the exhaust swing arm holder 105, i.e., the exhaust swing shaft 104 is located outside the parts of the exhaust valves 20 that are locked and connected to the exhaust swing arm 105, that is, the pusher adjusting screws 42.

The variable-lift mechanism 110 drives the exhaust valves 19 through the intake camshaft 31. The variable-lift mechanism 110 includes an intake swing arm 111 having a roller 114 that functions as an abutment portion of the cam that abuts the intake valve actuator cam 69 provided on the intake camshaft 31, a first connecting lever 112, the first end of which is rotatably connected to the inlet swing arm 111, and the second end of which is rotatably mounted in a fixed position on the housing 10 of the engine and a second connecting arm 113 having a first end rotatably coupled to the intake rocker arm 111 and a second end which is rotatably mounted on a support displaceable movable shaft 134.

As also shown in FIGS. 15-17, the intake swing arm 111 includes a valve connection portion 111a at its first end; pusher adjusting screws 70, 70, which are adjacent to the upper ends of the stems 19a of the inlet valve pair 19, are screwed onto the valve connection portion 111a so that their forward / backward position can be adjusted. At the second end of the intake swing arm 111, a first support portion 111b and a second support portion 111c located below the first support portion 111b are contained so that they are connected to each other. The first and second support portions 111b and 111c are formed to give them a substantially U-shape that opens in a direction opposite to the direction in which the U-shape of the intake valve 19 opens.

A roller 114 is mounted on a first support portion 111b of the intake swing arm 111 through a first connecting shaft 115 and a roller bearing 116; moreover, the roller 114 is in rolling contact with the cam 69 of the intake valve of the intake camshaft 31. The roller 114 is located so that it is installed between the linear sections of the U-shaped first support section 111b.

As also shown in FIG. 18, the intake swing arm 111 is formed, for example, by light alloy casting so that the valve connecting portion 111a has a larger width in the direction along the axis of rotation of the intake valve actuator cam 69 than in the rest. The first and second connecting portions 111b and 111c are formed so that they have the same width.

For example, a substantially triangular facilitating portion 117 is formed on a central portion of the upper surface of the inlet swing arm valve connecting portion 111a. A pair of facilitating portions 118, 118 are formed on opposite sides of the lower surface of the valve connecting portion 111a that are opposite the upper surface so that facilitating sections 118, 118 are alternately arranged.

The lightening portions 117, 118, 118 are formed at the same time as the inlet swing arm 111 is molded. The upper lightening portion 117 has a slope angle corresponding to such a direction that the lightening portion 117 has a larger opening area closer to the upper surface of the valve connection portion 111a. The lower relief portions 118, 118 have a slope angle corresponding to such a direction that the relief portions 118, 118 have a larger opening area closer to the lower surface of the valve connection portion 111a. Accordingly, the inner flange of the facilitating portion 117 has the same inclination direction as the inner surfaces of the facilitating portions 118, 118. Wall portions 111d, 111d are formed on the valve connecting portion 111a between adjacent facilitating portions 117, 118; wherein sections 117, 118 have substantially the same thickness.

As also shown in FIG. 19, the first connecting lever 112 has a pair of connecting sections 112a, 112a at its first end, while a first supporting portion 111b of the intake swing arm 111 is installed between the connecting sections 112a, 112. The first connecting lever 112 is generally formed by giving it a substantially U-shape. The first connecting lever 112 is rotatably connected to the first support portion 111b through the first connecting shaft 115, which allows axial mounting of the roller 114 on the inlet swing arm 111. A fixed support shaft 119 on which the second end of the first connecting lever 112 is rotatably mounted mounted on the upper holders 98 mounted on the cylinder head 14.

The first end of the second connecting lever 113, located below the first connecting lever 112, is mounted so that it is located between the linear sections of the U-shaped second support section 111c of the inlet swing arm 111. The first end of the second connecting lever 113 is rotatably connected to the second supporting section 111c through the second connecting shaft 120.

On the opposite sides of the second end of the first connecting lever 112, the supporting protrusions 112, 112 are made as a single piece with the upper holders 98, 98, so that they protrude from them, holding the fixed support shaft 119. The supporting protrusions 121 regulate the movement of the second end of the first connecting lever 112 in the axis direction of the fixed support shaft 119.

Both inlet valves 19 are spring-loaded with valve springs 24 in the closing direction of the valves. When the intake swing lever 111 drives both intake valves 19 in the valve opening direction, the intake valves 19 being spring loaded with valve springs 24 in the closing direction of the valves, the intake swing lever roller 114 is in contact with the intake valve actuator cam 69 under the action of the valve springs 24. However, when the intake valves 19 are closed, the spring side force exerted by the valve springs 24 does not act on the intake swing arm 111. The roller 114 may deviate from the intake valve actuator cam 69. This reduces the accuracy of controlling the valve lift when the intake valves 19 need to be opened slightly. While the torsion springs 122, performing the function of the inserts, are installed separately from the valve springs 24; torsion springs 122 are inserts located between support bumps 121, 121 located on opposite sides of the second end of the first connecting arm 112. Torsion springs 122 spring the inlet swing arm 111 in the direction in which the roller 114 is adjacent to the inlet valve actuator cam 69.

Torsion springs 122 surround the support bumps 121 and are located between the engine housing 10 and the inlet swing arm 111. In particular, the first ends of the torsion springs 122 are engaged with the support bumps 121. The second ends of the torsion springs 122 are inserted and connected to the hollow first connecting shaft 115, working integrally with intake swing arm 111.

The second end of the first connecting lever 112 is formed in the form of a cylinder so that its outer contour is located inside the outer contours of the torsion springs 122 in a side view. A plurality of, for example, a pair of protruding portions 123, 124 are provided at opposite ends in the axial direction of the second end of the first connecting lever 112 and at intervals in the direction along the circumference so that they protrude from the second end; however, the protruding sections 123, 124 do not allow the torsion springs 122 to fall down in the direction of the first connecting lever 112. Therefore, the torsion springs 122 do not fall down, as described above, which improves the rigidity of the support of the second end of the first connecting lever 112, preventing an increase in the size of the second end of the first the connecting lever 112.

In addition, the protruding sections 123, 124 are located outside the operating range of the second connecting lever 113. Accordingly, even though the protruding sections 123, 124 are provided at the second end of the first connecting lever 112, for the operation of the second connecting lever 113 can be Enough space is provided.

The oil spray nozzles 125 are mounted in the covers 99 of the intake cam holders 101 provided on the engine housing 10 to supply oil to the upper part of the second end of the intake swing arm 111.

A channel 126 is formed in one of the plurality of upper holders 98 for supplying oil from an oil pump (not shown). In addition, concave sections 127 formed in the form of a circular arc are provided on the upper part of the upper holders 98 and opposite the lower half of the intake camshaft 31. The channel 126 is connected to one of the concave sections 127. On the other hand, the intake camshaft 31 is formed coaxially with the oil channel 128. The connecting holes 129 are formed in the intake camshaft 31 in positions corresponding to the inlet cam holders 101 so that their inner ends are connected to the oil channel 128, and their external their ends are open on the outer surface of the intake camshaft 31. Lubricating oil is supplied between each intake cam holder 101 and the intake camshaft 31 through the connecting hole 129.

Concave sections 130 are formed on the lower surfaces of the covers 99 constituting the inlet cam holders 101 with the upper holders 98, wherein each of the concave sections 130 forms a channel between the upper surface of the corresponding upper holder 98 and the lower surface of the corresponding cover 99, while the channel extends to the concave section 127. Oil spray nozzles 125 are mounted on covers 99 so that they are connected to channels 131 formed on covers 99 and leading to concave portions 130.

The oil spray nozzles 125 are thus mounted on the covers 99 of the intake cam holders 46 provided on the engine housing 10 so that the intake camshaft 31 is rotatably mounted thereon. As a result, a sufficient amount of oil under sufficient pressure can be supplied through the oil spray nozzles 125 using an oil channel for lubrication between the intake camshaft 31 and the intake cam holders 101.

In addition, oil from the oil spray nozzles 125 is supplied to the first connecting shaft 115, which is the upper one of the first and second connecting shafts 115, 120 connecting the first ends of the first and second connecting levers 112, 113 with the inlet swing arm 111. As a result, the oil , after lubrication between the first connecting lever 112 and the intake swing arm 111, flows down to the second connecting lever 113.

In addition, oil supply openings 132, 133 are formed on the second connecting arm 113 in a direction orthogonal to a straight line connecting together the axes of the movable support shaft 134 and the second connecting shaft 120; the oil supply openings 132, 133 ensure that the movable support shaft 134 and the second connecting shaft 120 partially face the intermediate portion. The first ends of the oil supply holes 132, 133 are open in the direction of the first connecting shaft 115. Therefore, oil flowing down from the first connecting lever 112 is guided between the second connecting lever 113 and between the movable support shaft 134 and the second connecting shaft 120. Thus, it is possible to use a simple lubrication circuit with a reduced number of parts for lubricating the connection between the intake swing arm 111 and the first and second connecting arms 112 and 113, as well as the area between the second connecting arm 113 and a movable support shaft 134. This ensures smooth operation of the valves.

The movable support shaft 134, on which the second end of the second connecting lever 113 is rotatably mounted, is mounted on one control shaft 135, which is mounted on the engine housing 10, and is used for a plurality of cylinders arranged in a line. The control shaft 135 has the shape of a crank shaft and contains cheeks 135a and 135b located on opposite sides of the inlet swing arm 111, trunnion sections 135b, 135b connected at right angles to the outer surfaces of the proximal ends of the cheeks 135a, 135a and mounted to rotate on a motor housing 10, and a connecting portion 135c that connects the cheeks 135a, 135a together.

Each of the trunnion sections 135b of the control shaft 135 is mounted so that it can rotate between a corresponding upper holder 98 connected to the cylinder head 14 of the engine housing 10 and a corresponding lower holder 136 connected to the upper holder 98 from below. The lower holders 136 are formed separately from the cylinder head 14, so that they are attracted to the upper holders 98. Concave portions 137 are formed on the upper surface of the cylinder head 14 so that the lower holders 136 can be located in the concave portions 137.

In addition, a roller bearing 139 is located between each of the upper and lower holders 98 and 136 and the corresponding trunnion portion 135b. The roller bearing 139 can be divided into two parts, so that it can be located between the spigot portion 135b of the control shaft 135 and each of the upper and lower holders 98 and 136, while the control shaft 135 has a plurality of cheeks 135a, 135a and connecting portions 135c shared for multiple cylinders.

Sections 140 of the supporting bulges of the control shaft are formed on the upper and lower holders 98 and 136, so that they penetrate into sections 135A of the pins; however, sections 140 of the supporting convexities of the control shaft protrude outward in the direction of the cheeks 135a of the control shaft 135. On the other hand, each section 141 of the supporting convexity of the camshaft penetrating the intake camshaft 111 is formed on the upper holders 98 and the covers 99 so that it protrudes in the direction of the intake swing arms 111, while the upper holders 98 and the covers 99 are connected together so that they together constitute the intake cam holders 101. The ribs 142 are made as a single part with the upper holders 98, so that they protrude from them, and each of the ribs 142 connects together the corresponding section 140 of the supporting convexity of the control shaft and the corresponding section 141 of the supporting convexity of the camshaft.

Channels 143 are formed in ribs 142 so that they lead to concave portions 127 on the upper surfaces of the upper holders 98; while the channels 143 direct the oil to the roller bearings 139.

The swing supporting portion of the exhaust swing arm 105 is located in the cylinder head 14 so that it is located outside the portion of the exhaust swing arm 105 that is locked and connected to the exhaust valves 20. In contrast, the fixed support shaft 119 and the movable support shafts 134 are located in the cylinder head 14 in a line inside the portion of the intake swing arm 111, which is interlocked and connected to the intake valves 19.

The cylinder 145 for the spark plug is installed in the cylinder head 14; the spark plug 144, mounted on the cylinder head 14, is inserted into the spark plug cylinder 145 so that it faces the combustion chamber 15. The spark plug cylinder 145 is tilted so that its upper portion is closer to the exhaust valves 20.

The control shaft 135 is thus arranged such that the outer surface of each connecting portion 135c is opposite the spark plug cylinder 145 between the corresponding intake valve 19 and the corresponding spark plug cylinder 145. Clearance grooves 146 are formed on the outer surfaces of the connecting portions 135c so as to prevent interference with the spark plug cylinders 145.

When the intake valves 19 are closed, the second connecting shaft 120 connecting the second connecting lever 113 to the inlet swing arm 111 is coaxially mounted to the trunnion portions 135b of the control shaft 135. When the control shaft 135 is tilted around the axes of the trunnion portions 135b, the movable support shaft 60 moves along a circular arc centered on each section of 135b pins.

One of the trunnion portions 135b of the control shaft 135 protrudes from a support hole 16a formed in the head cover 16. The control lever 71, mounted on the tip of this axle portion 135b, is driven by a drive motor 72, which is mounted on the outer wall of the cylinder head 14, as in the first embodiment.

According to a second embodiment, in the variable lift mechanism 110, which constantly changes the lift amount of the intake valves 19, the first ends of the first and second connecting arms 112 and 113 are rotatably connected to the intake swing arm 111, which has a valve connection portion 111 a interlocked and connected to a pair of intake valves 19. The second end of the first connecting lever 112 is rotatably mounted on a first fixed support shaft 119, which is mounted on the engine housing 10. The second end of the second connecting arm 113 is rotatably mounted on a movable movable support shaft 134.

Therefore, the lift amount of the intake valves 19 can be continuously changed by constantly shifting the movable support shaft 134. This allows the intake amount to be controlled without the need to use any butterfly valve. In addition, since the first ends of the first and second connecting arms 112, 113 are rotatably connected directly to the inlet swing arm 111, it is possible to reduce the size of the space in which both connecting arms 112, 113 are mounted, and thus the size of the valve drive system. The power from the intake valve actuator cam 69 is transmitted directly to the roller 114 of the intake swing arm 111. This allows the intake swing arm 111 to correctly follow the intake valve actuator cam 69. In addition, the intake swing arm 111 and the first and second connecting arms 112, 113 can be arranged in substantially the same position in the direction along the axis of the intake camshaft 31. This makes it possible to reduce the size of the intake valve drive system in the direction along the axis of the intake camshaft 31.

In addition, the first end of the first connecting lever 112 is rotatably connected to the inlet swinging lever 111 through the first connecting shaft 115. The roller 114 is mounted on the inlet swinging lever 111 through the first connecting shaft 115. As a result, the common first connecting shaft 115 is used to connect to the possibility of rotation of the first end of the first connecting lever 112 with the inlet swing arm 111, which allows for the installation of the roller 114 on the axis of the inlet swing arm 111. the number of parts required and thus further reduce the size of the intake valve drive system.

Among the intake and exhaust valve drive systems, the intake valve drive system comprising a variable connection mechanism 110, a fixed support shaft 119 and a movable support shaft 134 is located inside a portion of the intake swing arm 111, which is interlocked and connected to the intake valves 19. The swing support portion of the exhaust swing the lever 105 of the exhaust valve drive system is located outside the portion of the exhaust swing arm 105, interlocked and connected to the exhaust valves 20. As a result, even if Since the clamping a (see Fig. 12) of the intake valves 19 and exhaust valves 20 are set to small values, it is possible to prevent an increase in the size of the cylinder head 14 and thus prevent mutual interference between the intake valve drive system and the exhaust valve drive system.

The exhaust valve drive system comprises an exhaust camshaft 103 having an exhaust valve actuator cam 107 and an exhaust swing arm 105, interlocked and connected to an exhaust valve 20 mounted on the engine housing 10 through the exhaust swing shaft 104 in such a way that it is swingable so that he follows the cam 107 of the exhaust valve drive. A spark plug cylinder 145 located between the intake valve drive system and the exhaust valve drive system is mounted on the cylinder head 14 so that it is tilted so that its upper portion is closer to the exhaust valve drive system. As a result, the spark plug cylinder 145 can be positioned so as to prevent interference with the intake and exhaust valve drive systems. This contributes to an additional reduction in the size of the entire cylinder head 14.

The control shaft 135 of the variable connection mechanism 110 is connected to the movable support shaft 134 so that it can be offset at an angle parallel to the axis of the movable support shaft 134. The control shaft 135 is mounted on the motor housing 10 on opposite sides of the inlet swing arm 111. As a result, such a centrifugal holder type improves the reference stiffness of the control shaft. Thus, it becomes possible to accurately perform variable control of the amount of lift of the intake valves 19.

In addition, one control shaft 135 is mounted on the motor housing 10, so that it is shared by a plurality of cylinders arranged in a line. This prevents an increase in the number of parts required, thus allowing a reduction in engine size.

In addition, the control shaft 135 is in the form of a crank shaft and has cheeks 135a and 135b located on opposite sides of the intake swing arm 111, trunnion sections 135b, 135b fixed at right angles to the outer surfaces of the proximal ends of the cheeks 135a, 135a, and mounted rotatably on the engine housing 10, and a connecting portion 135c that connects the cheeks 135a, 135a together. The movable support shaft 134 is connected to the control shaft 135 so that it connects the cheeks 135a and 135b together. This allows you to increase the rigidity of the control shaft 135, which is offset in angle with the transmission of the drive force.

Each of the pivots 135b of the trunnions of the control shaft 135 is mounted so that it can be rotated between a corresponding upper holder 98 connected to the cylinder head 14 of the engine housing 10 and a corresponding lower holder 136 connected to the upper holder 98 from below. This makes it possible to more easily and efficiently assemble the control shaft 135 on the engine housing 10. In addition, the lower holders 136, which are separate from the cylinder head 14, are tightened on the upper holders 98. Thus, it becomes possible to increase the degree of freedom of the design of the cylinder head 14 in conjunction with the installation of the control shaft 135.

In addition, a roller bearing 139, each of which can be divided into two parts, is located between each of the upper and lower holders 98 and 136 and the corresponding trunnion section 135b. This makes it possible to more easily and efficiently assemble the control shaft 135, while reducing friction losses in the portion of the holder for the control shaft 135.

The interconnected upper and lower holders 98 and 136 are formed so that the sections 140 of the supporting convexity of the control shaft protrude in the direction of the cheeks 135a of the control shaft 135. The portion 135b of the axle penetrating into each of the sections 140 of the supporting convexities of the control shaft is set so that it can rotate between each of the upper holder 98 and the corresponding lower holder 136. This further improves the rigidity of the control shaft 135.

The camshaft support convex portion portions 141 protruding in the direction of the intake swing arms 111 are formed on the upper holders 98 and the covers 99 connected to the upper holders 98 from above. The intake camshaft 111 extends into the camshaft support convex portions 141 and is rotatably mounted between each of the upper holders 98 and the corresponding cover 99. This improves the rigidity of the intake camshaft 111 by minimizing the number of parts required for installing the intake camshaft 111.

In addition, the rib 142 protrudes from each of the upper holders 98, connecting together the corresponding portion 140 of the supporting convexity of the control shaft and the corresponding portion 141 of the supporting convexity of the camshaft. This further improves the mounting rigidity of the control shaft 135 and the intake camshaft 111.

The control shaft 135 is located between the intake valves 19 and the spark plug cylinder 145, which is provided in the cylinder head 14, so that the outer surface of the connecting portion 135c is opposite the spark plug cylinder 145. A gap groove 146 is formed on the outer surface of the connecting portion 135c. This allows the spark plug cylinder 145 to be positioned closer to the intake valve drive system. Therefore, the size of the engine can be reduced.

In addition, facilitating portions 117, 118, 118 on opposite sides of the valve connecting portion 111 a are alternately formed on the intake swing arm 111. As a result, the weight of the intake swing arm 111 can be reduced.

The lightening portions 117, 118, 118 are molded simultaneously with the molding of the inlet swing arm 111. Since the adjacent lightening portions 117, 118; 117, 118 have slope angles corresponding to opposite directions, inner surfaces of adjacent lightening portions 117, 118; 117, 118 are tilted in one direction. Therefore, the wall portions 111d formed on the intake swing arm 111 between adjacent facilitating portions 117, 118; 117, 118 have substantially equal thickness. The rigidity of the inlet swing arm 111 can be maintained thanks to the wall sections 111d, 111d having a substantially equal thickness.

In addition, the variable lift mechanism 110 can constantly change the lift amount of the intake valves 19. Accordingly, even in a valve drive system, which typically has a relatively large number of parts and thus increased weight, the weight of the system can be reduced by facilitating the intake swing arm 111. This allows you to increase the critical speed of rotation.

Embodiments of the present invention have been described above. However, the present invention is not limited to these embodiments. Various changes may be made with respect to the design of the embodiments without departing from the present invention presented in the claims.

Claims (10)

1. The valve drive system of an internal combustion engine, comprising a swing arm (63, 111), which is connected to an engine valve (19) and which has an abutment portion (65, 114) adjacent to the valve actuator cam (69), a first connecting lever (61, 112), one end of which is rotatably connected to a swinging lever (63, 111), and the other end of which is rotatably mounted and fixed to the motor housing (10), a second connecting lever (62, 113), one end of which is connected rotatable with rocker arm (63, 111), and the other end of which is rotatably connected to a movable movable support shaft (68a, 134), and drive means (72) connected to the movable support shaft (68a, 134), which allows shifting the position of the movable support shaft ( 68a, 134) for constantly changing the lift of the valve (19) of the engine, in which the swing arm (63, 111) having a section (63a, 111a) of connection with the valve, into which the adjusting screws (70) of the pusher are screwed adjacent to the pair of valves (19) the engine so that it is possible to adjust their position forward / backward, and first and second support portions (63b, 63c; 111b, 111c) to which the ends of the first and second connecting arms (61, 62; 112, 113) are rotatably formed so that the valve connecting portion (63a, 111a) has a large width in the direction along the axis of rotation of the actuator cam ( 69) valve than in the rest. 2. The system according to claim 1, in which the other end of the first connecting lever (61, 112) is mounted for rotation on a fixed support shaft (67, 119), fixed mounted on the base walls (44a, 98) provided on the housing (10 ) the engine so that they are located on opposite sides of the other end of the first connecting lever (61, 112), while between the other end of the first connecting lever (61, 112) and each of the walls of the base (44a, 98) is an insert (54, 122 ) 3. The system according to claim 2, in which the insert (54, 122) is a torsion spring provided between the engine housing (10) and the swing arm (63, 111), so that it springs the swing arm (63, 111) into the side on which the cam contact portion (65, 114) is adjacent to the valve actuator cam (69). 4. The system according to claim 1, in which the first support section (63b, 111b) is formed to give it a substantially U-shape, so that a roller (65, 114) is inserted between its opposite sides, which is an abutment section to the cam, and the roller (65, 114) is rotatably mounted on the first support portion (63b, 111b). 5. The system according to claim 4, in which a pair of connecting sections (61a, 112a) is provided at one end of the first connecting lever (61, 112), so that a first supporting section (63b, 111b) is installed between the connecting sections (61a, 112a) swing arm (63, 111), while the connecting sections (61a, 112a) are rotatably connected to the first supporting section (63b, 11 lb) through the connecting shaft (64, 115), and on the first supporting section (63b, 111b) a roller (65, 114) is mounted on the axis through the connecting shaft (64, 115). 6. The system according to claim 1, in which the swing arm (63, 111) is formed so that the first and second support sections (63b, 63 s; 111b, 111c) have the same width. 7. The system according to claim 1, in which the connecting holes (49, 50) through which the connecting shafts (64, 66) are inserted, used to rotatably connect one end of the first and second connecting levers (61, 62), are formed in the first and second supporting sections (63b, 63c) so that they are located next to each other in the directions of opening / closing the valve (19) of the engine, and the first and second supporting sections (63b, 63c) are connected together using a connecting wall, at least partially opposite the valves (19) of Tell with respect to a tangent (L), which is held in contact with the external walls of the connecting holes (49, 50). 8. The system according to claim 7, in which a concave portion (51) is formed in the connecting wall (63d) in a position opposite the other end of the second connecting arm (62), when the other end of the second connecting arm (62) is closest to the swing arm ( 63). 9. The system of claim 7, wherein a facilitating portion (52) is formed on the connecting wall (63d). 10. The system of claim 1, wherein the lightening portions (117, 118) are alternately formed on alternating molded surfaces of the swing arm. Priority on points: pp. 1.4-9 of 16.01.2004; paragraphs 2.3 dated 02.12.2004; Clause 10 dated January 30, 2004.

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