KR20020071490A - Valve driving device for internal combustion engine - Google Patents

Abstract

PURPOSE: A valve-driving device for an internal combustion engine is provided to reduce the space for valve-related parts around a cylinder head, to increase the efficiency of an engine and to make a valve lift smaller and lighter. CONSTITUTION: A valve driving device using a direct driving type valve lifter(101) which is disposed between a cam(102) formed at a cam shaft and a poppet valve(105) provided in a path formed at a cylinder head(111) of an internal combustion engine, and moves to the axial direction of the valve to open and close the path. The valve driving device includes a guide hole(123) formed at the cylinder head(111), the direct driving type valve lifter(101) having a tappet portion(103) which is brought in contact with the cam(102) and pressed by the cam(102), a guide portion(104) having one end portion coupled to the tappet portion(103) and housed within the guide hole(123) to slide freely in the axial direction of the poppet valve(105) in an interlocked manner as the pushing operation of the tappet portion(103) by the cam(102), and the diameter of the guide portion(104) is smaller than the diameter of the tappet portion(103).

Description

Valve Driving Device for Internal Combustion Engine

The present invention relates to a valve drive device for driving a valve for opening and closing an intake port or an exhaust port of an internal combustion engine. In particular, the present invention realizes a valve driving apparatus using a direct drive valve lifter in which the valve is small in size and light in weight while ensuring a sufficient lift amount to improve operation performance.

A valve driving apparatus using a direct drive valve lifter is known from, for example, Japanese Patent Laid-Open No. 10-331709. The direct drive valve lifter has a tappet part in contact with a cam provided on the upper side of the cylinder head of the internal combustion engine, and a guide part slidably received in the cylinder head. The valve lifter is provided between the cam and the valve so that the tappet portion is pressed against the cam convex portion by the rotation of the cam so that the guide portion slides in the cylinder head. As a result, the valve moves integrally with the valve lifter in its axial direction, and the intake port or exhaust port provided with the valve is opened and closed.

The tappet portion in contact with the cam convex portion is circular and almost planar, and is in linear contact with the cam convex portion. The cam profile is designed so that this contact position with the cam convex portion does not deviate within the diameter of the tappet portion and at the same time an acceptable contact weight is obtained.

For example, it is necessary to increase the open valve area of the valve in order to increase the amount of intake air and improve the output of the internal combustion engine. It is necessary to increase the lift amount of the valve in order to increase the open valve area of the valve, and the diameter of the tappet portion is set so that the lift amount of the valve can be sufficiently secured.

In order to secure the lift amount required for the valve, the diameter of the tappet part must be set according to the lift amount. Increasing the diameter of the tappet portion increases the diameter of the guide portion, thereby increasing the valve lifter. On the other hand, since various mechanisms and structures exist around the cylinder head of the internal combustion engine, the valve lifter also places restrictions on its installation location. For this reason, there is a limit to the enlargement of the valve lifter, and the problem is how the valve lifter is provided in the restricted space and how to secure the lift amount of the valve. This problem is particularly noticeable in small internal combustion engines.

In addition, simply increasing the size of the valve lifter may increase the inertia weight of the valve operating system and may make it difficult to secure necessary performance of the internal combustion engine. In addition, when the inertial weight of the valve operating system increases, it is necessary to increase the spring force of the spring system for pressurizing the valve in the closing direction, and the contact pressure between the tappet part and the cam increases, which causes problems such as wear.

The conventional valve drive device also has a problem with respect to lubrication performance. This problem will be described with reference to FIGS. 25 and 26. 25 and 26 show a schematic configuration of a valve drive device using a conventional direct drive valve lifter. 25 illustrates a state in which the valve lifter is not pressurized, and in FIG. 26, the valve lifter is pressurized.

As shown in these figures, a cam 902 is provided above the cylinder head 901 of the internal combustion engine, and a guide hole 903 is provided in the cylinder head 901. The guide hole 903 is provided. The cylindrical part (guide part) of the cylindrical valve lifter 904 is slidably accommodated, and the cam 902 is in contact with the upper surface (head part) of the valve lifter 904. The valve 905 (intake valve, exhaust valve) is provided on the opposite side to the cam 902 with the valve lifter 904 attached.

The valve lifter 904 is pressurized by the rotation of the cam 902 to reciprocate in the guide hole 903 to open and close the valve 905. An oil reservoir 906 is formed around the upper portion of the guide hole 903 so that the lubricating oil 907 is collected. When the valve lifter 904 is pressurized, the tap convex portion and the cam convex portion of the cam 902 are oil reservoir 906. Is immersed in the lubricating oil 907 inside.

In many internal combustion engines, a predetermined clearance is set between the guide hole 903 and the valve lifter 904 so that the valve lifter 904 can be operated even at cryogenic temperatures. The lubricating oil 907 in the oil reservoir 906 is supplied by the rotation of the cam 902, the vertical movement of the valve lifter 904, and the own weight of the lubricating oil 907, thereby lubricating each part.

As described above, the cam convex portion of the cam 902 is in line contact with the tappet portion of the valve lifter 904. Then, the contact position is in a state of moving within the diameter of the tappet part, the position of the load point of the tappet part changes, and the valve lifter 904 receives the opposite moment when reciprocating.

For this reason, when the lubricating oil 907 is a high temperature, the clearance between the guide hole 903 and the valve lifter 904 becomes large, and since the oil viscosity of lubricating oil is low, the noise by an oil film burst occurs and friction increases. In addition, the clearance between the guide hole 903 and the valve lifter 904 becomes small at low temperature, and the lubricating oil 907 hardly flows in the side part of a guide part, and friction increases. Therefore, there is a possibility that the output of the internal combustion engine and the fuel economy may be deteriorated, and the wear of the valve lifter 904 or the like may be caused.

In addition, in many internal combustion engines, the cylinder head is made of aluminum, while the valve lifter is made of steel. For this reason, as described above, a predetermined clearance is set between the guide hole and the valve lifter so that the valve lifter can operate even at an extremely low temperature. At high temperatures, the clearance between the guide hole and the valve lifter becomes larger, and the inclination also becomes larger when the above-mentioned moment acts on the valve lifter. On the other hand, since the tappet portion of the valve lifter has a plate shape, the rigidity of the outer peripheral portion is high and it is difficult to deform.

Therefore, a large posture change occurs in the valve lifter at the time of maximum lift, and when the guide portion strikes the inner surface of the guide hole, the oil film of the clearance is pushed out and a large metal blow sound is generated. In addition, there was a fear that the frictional performance and wear increased, resulting in a decrease in the output performance and fuel economy of the internal combustion engine.

The present invention has been made to solve the above problems as a valve drive device for an internal combustion engine using a direct drive valve lifter, while ensuring a sufficient lift amount of the valve in a confined space, while reducing the size and weight of the valve drive improved operation performance To realize the device.

The valve drive device of the present invention is installed in a passage formed in the cylinder head of the internal combustion engine and is installed between the poppet valve for opening and closing the passage by moving in the valve axial direction and the cam formed in the cam shaft. A guide hole is formed in the cylinder head, and a tappet portion that is in contact with the cam and is pressed by the cam, and an end portion thereof is coupled to the tappet portion, interlocked with the pressing operation of the tappet portion by the cam. A direct drive valve lifter having a guide portion accommodated in the guide hole so as to slide in the axial direction of the poppet valve, the diameter of the guide portion being smaller than the diameter of the tappet portion.

The valve lifter can realize small size and light weight by securing the diameter that can realize the required lift amount by the valve driving device and by reducing the guide part. As a result, it is possible to ensure high engine performance while reducing the occupied area of the valve related parts around the cylinder head. In addition, the valve-related components can be compactly accommodated, which is advantageous in terms of space, and the degree of freedom is increased in the layout of other components. In addition, the small size and light weight of the valve lift can cope with the high speed of the internal combustion engine.

By providing the poppet valve driven by the valve drive device of the present invention in the intake passage of the internal combustion engine, it is possible to increase the amount of intake air as a light weight miniaturized valve lifter, and improve the driving performance of the internal combustion engine.

In the case of an internal combustion engine in which a cam shaft is provided above the cylinder head and one end of the intake passage is opened to the combustion chamber of the internal combustion engine, and the other end is opened to the upper surface of the cylinder head. The installation of the valve lifter is restricted. The valve drive device of the present invention can ensure a sufficient lift amount even in such a constraint.

Even when two or more poppet valves installed in each cylinder of the internal combustion engine are opened and closed by the valve lifter, the number of the valve lifters causes a limitation in the installation of the valve lifter. The valve drive device of the present invention can ensure a sufficient lift amount even in such a constraint.

By using the valve drive device of the present invention, a space is also provided in the installation space of the cylinder head bolt. More preferably, even when the cylinder head bolt is to be installed close to the valve lifter, the cylinder head bolt can be inclined with respect to the cylinder axis of the internal combustion engine, so that the cylinder head bolt can be tightened without interfering with the valve lifter.

Further, in the valve drive device of the present invention, an oil storage portion in which lubricating oil is accumulated is provided at an opening edge of the guide hole, and the tappet portion has a diameter that is at least partially larger than the diameter of the guide portion, and protrudes from the outer peripheral surface of the guide portion. The guide portion projects outward in the radial direction. In such a configuration, in addition to the above-described effect of compact weight, the valve lifter allows the protrusion to move into the oil reservoir when the valve is lifted. It is pressurized and it becomes possible to actively supply lubricating oil to each part of a valve lifter. As a result, friction decreases, the blow noise at the time of the posture change of a valve lifter can be reduced, abrasion is reduced, the output performance and fuel economy of an internal combustion engine are improved, and durability reliability is improved.

In the valve drive device of the present invention, by providing a gap in which the lubricant oil can be scattered between the outer circumferential portion of the oil storage portion and the edge of the tappet portion, the lubricant is guided by the lower surface of the tappet portion when the valve lift is pressurized. At the same time, the lubricant is splashed between the guide holes and the lubricant flows from the gap, so that the lubricant flows into the upper surface of the tappet portion.

Further, by expanding the width of the gap in the direction orthogonal to the rotational center axis line of the cam and the vicinity thereof, the lubricant can be actively scattered on the cam side.

This effect is similarly obtained by providing the gap only in the direction orthogonal to the rotational center axis of the cam.

If the valve lifter is inclined in a direction perpendicular to the rotational center axis of the cam with respect to the vertical direction, the clearance may be provided only in a direction downward and in the vicinity of two directions orthogonal to the rotational center axis of the cam. Effect is obtained.

In the valve drive apparatus provided with the said oil storage part, if the diameter of the said tappet part is made smaller than the diameter of the base circle of the said cam, the lubricating oil which scatters can be guide | induced directly to a cam.

In the direct drive valve lifter used in the valve drive device of the present invention, when the guide portion is accommodated in the guide hole, an elastic deformation promoting portion for promoting the elastic deformation of the guide portion is provided. When a change occurs, the elastic deformation of the guide portion is promoted. For this reason, it is possible to reduce the impact noise caused by the posture change, to prevent the increase of friction, to improve the durability, and to improve the output performance and fuel economy of the internal combustion engine.

By providing the elastic deformation promoting portion in the guide portion near the boundary between the tappet portion and the guide portion, the guide portion can be easily elastically deformed along the guide hole at the time of the posture change.

In addition, when the elastic deformation promoting portion provided near the boundary between the tappet portion and the guide portion is a groove formed in the circumferential direction of the guide portion, the groove can be used as a gap portion in the rear surface of the tappet portion or in the abrasive machining of the guide portion outer circumference. Also, valve lifter processing can be facilitated.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 shows a schematic configuration of a valve drive device according to a first embodiment of the present invention.

FIG. 2 is a view illustrating a main configuration of an internal combustion engine to which the valve driving device of FIG. 1 is applied. FIG.

FIG. 3 is a view showing the main structure of FIG. 2 in the cylinder axial direction of the internal combustion engine; FIG.

4 and 5 are front views showing a schematic configuration of a valve drive device according to a second embodiment of the present invention.

6 is a front view showing a schematic configuration of a valve drive device according to a third embodiment of the present invention.

7 and 9 are front views showing a schematic configuration of a valve drive device according to a fourth embodiment of the present invention.

8 and 10 are side views showing a schematic configuration of a valve drive device according to a fourth embodiment of the present invention.

Fig. 11 is a diagram taken along the line VII-VII in Figs. 7 and 9;

12 and 13 are front views showing a schematic configuration of a valve drive device according to a fifth embodiment of the present invention.

14 is a view taken along the line XI-XI in FIG. 12;

15 and 16 are front views showing a schematic configuration of a valve drive device according to a sixth embodiment of the present invention.

FIG. 17 is a view taken along line XIV-XIV in FIG. 15; FIG.

18 is a front view showing a schematic configuration of a valve drive device according to a seventh embodiment of the present invention.

FIG. 19 is a view taken along line XVI-XVI in FIG. 18;

20, 21 and 23 show a schematic configuration of a valve drive device according to an eighth embodiment of the present invention.

FIG. 22 is a view taken along line III-III in FIG. 21;

FIG. 24 is a view taken along line V-V in FIG. 23;

25 and 26 show a schematic configuration of a conventional valve drive device.

<Description of the symbols for the main parts of the drawings>

101: valve lifter 102: cam

103: tappet portion 104: guide portion

105: valve 111: cylinder head

114: piston 115: valve seat

117: intake valve 118: exhaust valve

Fig. 1 shows a schematic configuration of a valve drive device according to the first embodiment of the present invention. In addition, Fig. 2 shows the main part configuration of the internal combustion engine to which the valve drive device of Fig. 1 is applied, and Fig. 3 shows the main part configuration of the Fig. 2 as seen from the cylinder axial direction of the internal combustion engine.

Based on FIG. 1, the structure of the valve drive apparatus of 1st Example is demonstrated. As shown in FIG. 1, the valve lifter 101 has a tappet portion 103 which is in contact with a cam 102 provided above the cylinder head 111 of the internal combustion engine, and the tappet portion 103 has a cam ( The part of 102 which contacts the cam convex part is substantially circular in a circular shape. The tap convex portion 103 and the cam convex portion of the cam 102 are in line contact. In addition, the valve lifter 101 has a hollow cylindrical guide portion 104 continuously below the tappet portion 103, which guide portion 104 is provided in the guide hole 123 of the cylinder head 111. It is slidably accommodated. The diameter r of the guide portion 104 is formed to a diameter smaller than the diameter R of the tappet portion 103.

By this structure, it becomes the tappet part 103 of diameter R which can ensure the required valve lift amount, ie, the tumble ratio more than a predetermined value, or the valve lift amount from which a desired flow volume is obtained, and the guide part 104 is carried out. By miniaturization of), the size and weight of the valve lifter 101 can be reduced. That is, the tappet part 103 of the diameter R obtained by obtaining the lift amount which secured high engine performance, while making the occupying area of the valve related parts around the cylinder head 111 small can be obtained. In addition, the valve-related components can be compactly accommodated, which is advantageous in terms of space, and also increases the degree of freedom in the layout of other components. In addition, by reducing the size and weight of the valve lifter 101, it becomes possible to cope with the high speed of the internal combustion engine.

In the guide part 104 of the valve lifter 101, the government part of the shaft part of the valve 105 contacts and is installed, and the valve 105 is pressurized upward by the spring which is not shown in figure. . That is, the valve lifter 101 is provided between the cam 102 and the valve 105. Rotation of the cam 102 causes the cam convex portion to contact the tappet portion 103 to pressurize the valve lifter 101, and the valve 105 is pressurized together with the valve lifter 101 to resist the pressing force of the spring, thereby actuating the valve. Will open. Due to the small size and light weight of the valve lifter 101, the inertial load of the valve operating system is reduced, so that it is not necessary to increase the spring force of the spring, and wear of the cam 102 and the tappet portion 103 is less likely to occur.

The internal combustion engine provided with the valve drive device of the first embodiment will be described with reference to Figs. 2 and 3. As shown in FIG. 2, a cylinder 113 is provided in the cylinder block 112 of the internal combustion engine, and a piston 114 is provided in the cylinder 113 so as to reciprocate. The concave cavity 114a is formed in the top surface of the piston 114, and the cavity 114a forms the inverted tumble which the intake air in the cylinder 113 turns to just above. An intake valve seat 115 and an exhaust valve seat 116 are installed in the combustion chamber 110 of the cylinder 113. The intake valve seat 115 can be opened and closed by the intake valve 117 (valve 105), and the exhaust valve seat 116 can be opened and closed by the exhaust valve 118 (valve 105). have.

The cylinder block 112 and the cylinder head 111 are coupled by the head bolt 109. The valve lifter 101 is inclined along the axis of the intake valve 117 (or the exhaust valve 118) in the cylinder head 111, and the guide portion 104 is slidably supported by the cylinder head 111. have. The intake valve 117 (or the exhaust valve 118) is installed in the valve lifter 101 in a state in which it is pressurized in the open valve direction via the retainer 119 and the spring 120. The intake valve 117 and the exhaust valve 118 are provided in the cylinder head 111 at a predetermined narrow angle θ. Incidentally, the narrow angle θ of the intake valve 117 and the exhaust valve 118 may be the same or different.

The valve lifter 101 is formed so that the diameter r (see FIG. 1) of the guide portion 104 is smaller than the diameter R (see FIG. 1) of the tappet portion 103, and is inclined so as to be flat. This makes it possible to secure a space arbitrarily, and the design freedom of the narrow angle θ of the intake valve 117 and the exhaust valve 118 increases. Also, as shown in, for example, the exhaust valve 118 in FIG. 2, the shim 131 is interposed between the valve lifter 101 and the exhaust valve 118 (or the intake valve 117). It is possible.

The cylinder head 111 is provided with an intake port 121 leading to the intake valve seat 115 upright and at the same time an exhaust port 122 leading to the exhaust valve seat 116. Since the intake port 121 is installed upright and the intake valve 117 is provided with a predetermined narrow angle θ, the intake air from the intake port 121 can flow into the cylinder 113 almost immediately downward. As a result, a cavity 114a of the piston 114 generates an inverted tumble flow almost immediately upward in the cylinder 113. Fuel is injected directly to the combustion chamber 110, and layer-shaped combustion is enabled by the reverse tumble of intake air.

As shown in FIG. 3, the diameter R of the tappet portion 103 of the valve lifter 101 extends in the axial direction of the intake valve 117 (or the exhaust valve 118), and the head bolt ( The bolt seat surface working diameter d of 109 is provided in the state which overlapped in plan view. When the head bolt 109 is seen from the axis line, the head bolt 109 is a tappet part (without a valve lift). It does not overlap with 103. That is, when the pitch of the head bolt 109 is p and the pitch of the tappet part 103 is P,

P + R> p-d.

Since the valve lifter 101 is inclined, the head bolt 109 does not interfere with the valve lifter 101 even when the virtual circumference and the bolt seat surface diameter d overlap in plan view. Can be tightened. By overlapping the virtual circumference and the bolt seat surface working diameter d in a plan view, the pitch p of the head bolt 109 can be reduced, and the valve ensures high engine performance even in an internal combustion engine with a small displacement. Lift amount (high lift amount) can be realized.

In addition, in the above-described first embodiment, the valve lifter 101 is inclined and the present invention is applied to an internal combustion engine of the type in which fuel is injected directly into the combustion chamber 110. It is not limited to the thing of a 1st Example. That is, if the tappet part of the valve lifter 101 is pressurized by the cam 102, the present invention also applies to an internal combustion engine or the like in which the valve lifter 101 is installed in an upright state or a mixer is introduced into the combustion chamber 110. It is possible to apply. In addition, the relationship between the pitch P of the valve lifter 101 and the pitch p of the head bolt 109 is not limited to the above-mentioned example, The virtual circumference and bolt seat surface processing diameter d do not overlap in plan view. You can do that.

The above-described valve lifter 101 is installed in the intake port 121 (or exhaust port 122) formed in the cylinder head 111 of the internal combustion engine, and moves in the valve axis direction so that the intake port 121 (or exhaust port) It is provided between the intake valve 117 (or the exhaust valve 118) which opens and closes the 122, and the cam 102 formed in the cam shaft. The valve driving device using the valve lifter 101 is provided with a guide hole 123 provided in the cylinder head, and at the same time the tappet part 103 pressed against the cam 102 by being pressed against the cam 102. And an end portion is coupled to the tappet part 103, and in conjunction with the pressurization operation of the tappet part 103 by the cam 102, the axial direction of the intake valve 117 (or the exhaust valve 118). A direct drive valve lifter having a guide portion 104 accommodated in the guide hole 123 so as to slide therein, and the diameter r of the guide portion 104 is smaller than the diameter R of the tappet portion. Is formed. With such a configuration, the diameter of the tappet portion 103 is set to a diameter capable of securing a valve lift amount necessary for obtaining a tumble ratio or a desired flow rate of a predetermined value or more, and at the same time, the valve lifter ( 101 can be reduced in size and weight.

For this reason, high engine performance can be ensured, while the occupation area of the valve related parts around the cylinder head 111 is reduced. In addition, the valve-related components can be compactly accommodated, which is advantageous in terms of space, and increases the degree of freedom in the layout of other components. In addition, the small size and light weight of the valve lifter 101 can cope with the high speed of the internal combustion engine.

By inclining the valve lifter 101, even if the distance p between the seat surfaces of the head bolt 109 is shorter than the width P + D of the tappet portion 103, the tap lifter 103 does not interfere. The tightening operation of the head bolt 109 can be performed without. In addition, since the intake valve 117 can have a narrow angle θ, it is provided with a vertical intake port that generates reverse tumbles almost immediately in the combustion chamber 110, and directly injects fuel into the combustion chamber 110. It is also applicable to an internal combustion engine. It goes without saying that in an internal combustion engine that does not require a high lift, it is possible to achieve small size and light weight without changing the lift amount.

4 and 5 are front views showing the schematic configuration of the valve drive device according to the second embodiment of the present invention. 4 illustrates a state in which the valve lifter is not pressurized, and in FIG. 5, the valve lifter is pressurized.

As shown in these figures, a cam 212 is provided above the cylinder head 211 of the internal combustion engine, and a guide hole 213 is provided in the cylinder head 211. An ordinary guide portion 215 of the valve lifter 214 is slidably accommodated in the guide hole 213, and a tappet portion 216 is provided above the guide portion 215. The tappet portion 216 protrudes in the outer circumference of the guide portion 215 in the outer circumferential direction to form a protrusion 230, and the tappet portion 216 has a continuous umbrella shape on the upper portion of the guide portion 215. In the tappet portion 216, a portion of the tappet portion 216 contacting the cam convex portion of the cam 212 is substantially flat in a circular shape, and the tappet portion 216 and the cam 212 are in line contact with each other. In addition, all the periphery of the outer edge of the tappet part 216 may not protrude from the guide part 215, and the diameter may be changed and only a part of it may protrude from the guide part 215.

In the guide part 215 of the valve lifter 214, the top part of the axial part of the valve 217 (intake valve or exhaust valve) is installed so that the valve part 217 may contact upward, and the valve 217 is upwards by the spring which is not shown in figure. Is pressurized. That is, the valve lifter 214 is provided between the cam 212 and the valve 217. Rotation of the cam 212 causes the cam convex portion to contact the tappet portion 216 to pressurize the valve lifter 214, and the valve 217 is pressurized together with the valve lifter 214 in response to the pressing force of the spring to press the valve. Open operation.

An oil storage portion 218 is formed around the upper portion of the guide hole 213 (the tappet portion 216 side) as an oil storage portion where the lubricating oil 219 accumulates. The oil reservoir 218 has a tappet portion 216 having a slight gap. That is, the tappet part 216 moves the oil storage part 218 when the valve lifter 214 lifts. As shown in FIG. 4, the depth d of the oil reservoir 218 is from the upper surface of the tappet portion 216 to the bottom of the oil reservoir 218 when the valve lifter 214 is not pressurized. If the dimension is D and the valve lift amount is S, d≥DS is set.

In addition, as in the valve driving apparatus of the third embodiment shown in FIG. 6, when the valve 317 is installed at an oblique angle, even if the rear side of the tappet portion 316 is partially raised when the valve lifter 314 is lifted, it is oil level. It is laid out so that it may become lower than a surface.

In the valve drive device having the above-described configuration, the valve lifter 214 is loaded from the lift start of the valve lifters 214 and 314 to the maximum lift from the surface of the tappet sections 216 and 316 on the right side in FIG. 5 (FIG. 6). , 314 acts on the same direction as the rotational direction of the cam (212, 312). As a result, the valve lifters 214 and 314 are inclined to the right in the drawing, and the clearance between the guide parts 215 and 315 on the opposite side and the guide holes 213 and 313 increases from the upper side. When the upper clearance becomes large, the lubricating oils 219 and 319 of the oil reservoirs 218 and 318 are press-fitted by the rear surfaces of the tappet portions 216 and 316 immediately above (arrows A in Figs. 5 and 6), The clearance is filled with lubricants 219 and 319.

At the same time, lubricating oils 219 and 319 are extruded from the gaps between the outer edges of the tappets 216 and 316 and the oil reservoirs 218 and 318 (arrow B in FIGS. 5 and 6) and the cams 212 and 312. Lubricants 219 and 319 are delivered to the side. In addition, the lubricating oils 219 and 319 in the oil reservoirs 218 and 318 are agitated by the umbrella tappets 216 and 316, and the sludge and the like are discharged by the lift of the valve lifters 214 and 314.

After the maximum lift, the opposite moments act on the valve lifters 214 and 314, and the valve lifters 214 and 314 tilt to the left in FIG. 5 (FIG. 6). At this time, the above-mentioned clearance of the guide parts 215 and 315 and the guide holes 213 and 313 becomes small, but the lubricating oil 219 and 319 filled in the clearance produces a squeeze effect, and the valve lifters 214 and 314 The posture does not change suddenly.

In the above-described valve drive device, when the valve lifters 214 and 314 are lifted, the lubricating oils 219 and 319 of the oil reservoirs 218 and 318 are guided by the rear surfaces of the tappet parts 216 and 316. 315 is pressed between the guide holes 213 and 313. For this reason, lubricating oil 219 and 319 is lubricated between the guide parts 215 and 315 and the guide holes 213 and 313 irrespective of the viscosity of the lubricating oils 219 and 319. In addition, the lubricating oils 219 and 319 are extruded from the gap between the outer edges of the tappet portions 216 and 316 and the oil storage portions 218 and 318, and the lubricating oils 219 and 319 are delivered to the cams 212 and 312. Therefore, lubricating oils 219 and 319 are supplied to the contact surfaces between the cams 212 and 312 and the tappets 216 and 316.

For this reason, friction decreases, the impact noise at the time of the posture change of the valve lifters 214 and 314 can be reduced, abrasion is reduced, the output performance and fuel economy of an internal combustion engine are improved, and durability reliability is improved.

Next, with reference to Figs. 7 to 11, a fourth embodiment of the present invention will be described. 7 to 10 show a front view and a side view showing a schematic configuration of a valve drive device according to a fourth embodiment of the present invention. 7 and 8 illustrate a state in which the valve lifter is not pressurized, and FIGS. 9 and 10 illustrate a state in which the valve lifter is pressurized. 11 is a view taken along the line VII-VII in FIGS. 7 and 9.

As shown in these figures, the tappet portion 416 protrudes on the outer circumference of the guide portion 415 to form a protruding portion 430, and a lubricant 419 around the upper portion of the guide hole 413. An oil reservoir 421 is formed as an oil reservoir. 7, 9, and 11, the oil reservoir 421 has a notch portion 422 cut in a concave shape in a direction orthogonal to the rotation center axis of the cam 412 (left and right in the figure). Are installed respectively. 8 and 10, the oil storage part 421 in a part other than the notch part 422 (mainly in the direction along the rotational center axis of the cam 412) has a slight gap. The pit 416 is provided.

In the above-described valve drive device, when the valve lifter 414 is lifted, the lubricating oil 419 of the oil storage part 421 is press-fitted between the guide part 415 and the guide hole 413 by the back surface of the tappet part 416. Thus, lubricating oil 419 is lubricated between the guide portion 415 and the guide hole 413. Further, in the gap between the outer edge of the tappet portion 416 and the oil storage portion 421 mainly in the direction along the rotational center axis of the cam 212, the lubricant oil 419 is extruded and the lubricant oil 419 toward the cam 412 side. ) Is delivered. In addition, the lubricating oil 419 in the oil storage part 421 is stirred by the umbrella-shaped tappet part 416, and sludge etc. are discharged by the lift of the valve lifter 414. When the valve lifter 414 is lifted, the lubricant oil 419 is extruded from the notch portion 422 to the upper surface of the tappet portion 416, and a large amount of lubricant oil 419 is applied to the contact surface between the cam 412 and the tappet portion 416. ) Is guided and lubrication of the contact portion between the cam 412 and the tappet portion 416 is sufficiently performed.

For this reason, friction decreases, hitting noise at the time of the posture change of the valve lifter 414 can be reduced, abrasion is reduced, output performance and fuel economy of an internal combustion engine improve, and durability reliability is improved.

12 to 14, a fifth embodiment of the present invention will be described. 12 and 13 are front views showing a schematic configuration of a valve drive device according to a fifth embodiment of the present invention. 12 illustrates a state in which the valve lifter is not pressurized, and FIG. 13 illustrates a state in which the valve lifter is pressurized. 14, the arrow of the XI-XI line in FIG. 12 is shown.

As shown in these drawings, the valve 517 is inclined and provided in a narrow angle. The tappet portion 516 protrudes in the outer circumference of the guide portion 515 to form a protruding portion 530, and the oil storage portion as the oil storage portion in which the lubricating oil 519 accumulates around the upper portion of the guide hole 513. The part 526 is formed. The notch part 527 cut | disconnected in the concave shape is provided in the oil storage part 526 in the inclined inner side (left side of the figure) orthogonal to the rotation center axis line of the cam 512. As shown in FIG. The oil storage part 526 in parts other than the notch part 527 has a small gap, and the tappet part 516 is provided.

In the above-described valve drive device, when the valve lifter 514 is lifted, the lubricating oil 519 is extruded from the notch portion 527 to the upper surface of the tappet portion 516, and the contact surface between the cam 512 and the tappet portion 516. Lubricant 519 is delivered. In addition, the lubricating oil 519 in the notch portion 527 is pressurized by the tappet portion 516 at a high pressure, particularly in the high speed rotational speed region, so that the lubricating oil 519 splashes toward the wall surface of the cylinder head 511 or the like. Then, the lubricating oil 519 scattered in this way is returned to the wall surface or the like, and the base circle is led to the cam convex portion of the cam 512 having a diameter smaller than that of the tappet portion 516, and the cam 512 and the state Lubrication of the contact portion with the pit 516 is sufficiently performed.

For this reason, high friction and abrasion do not occur, the output performance and fuel economy of an internal combustion engine are improved, and durability reliability is improved.

15 to 17, a sixth embodiment of the present invention will be described. 15 and 16 are front views showing a schematic configuration of a valve drive device according to a sixth embodiment of the present invention. 15 illustrates a state in which the valve lifter is not pressurized, and FIG. 16 illustrates a state in which the valve lifter is pressurized. FIG. 17 is a view taken along line XIV-XIV in FIG. 15.

15 and 16, a cam 631 is provided above the cylinder head 611 of the internal combustion engine, and the diameter r of the tappet portion 616 is the diameter of the base circle of the cam 631. It is formed smaller than (R). The tappet portion 616 protrudes in the circumferential direction of the guide portion 615 in the outer circumference to form the protrusion portion 630, and stores oil as an oil storage portion where lubricant oil 619 accumulates around the upper portion of the guide hole 613. The part 632 is formed. As shown in FIG. 17, the oil storage part 632 is an enlarged diameter part so that the oil storage part 632 may have an ellipse shape in which the long part exists in the direction orthogonal to the rotation center axis line of the cam 631 (left-right direction in drawing). 633 are provided respectively. The oil storage part 632 in parts other than the enlarged diameter part 633 is in the state in which the tappet part 616 was provided with the slight clearance.

In the valve driving apparatus described above, the lubricating oil 619 is extruded from the enlarged diameter portion 633 to the upper surface of the tappet portion 616 when the valve lifter 614 is lifted, and the contact surface between the cam 631 and the tappet portion 616 is raised. Lubricant 619 is delivered. In addition, the lubricating oil 619 in the enlarged diameter portion 633 is pressurized and scattered by the tappet portion 616 particularly in the high speed rotational speed region. At this time, since the diameter r of the tappet portion 616 is smaller than the diameter R of the base circle of the cam 631, the lubricated oil 619 scattered directly into the cam convex portion of the cam 631. Guided by the cam 631 and the tappet portion 616 is sufficiently lubricated.

For this reason, high friction and abrasion do not occur, the output performance and fuel economy of an internal combustion engine are improved, and durability reliability is improved.

18 and 19, a seventh embodiment of the present invention will be described. 18 is a front view showing a schematic configuration of a valve drive device according to a seventh embodiment of the present invention. FIG. 19 is a view taken along line XVI-XVI in FIG. 18.

As shown in these drawings, the valve 717 is inclined and provided in a narrow angle. The tappet portion 716 protrudes in the outer circumference of the guide portion 715 in the circumferential direction to form a protrusion portion 730, and an oil storage portion as an oil storage portion in which lubricating oil 719 accumulates around the upper portion of the guide hole 713. 736 is formed. The oil storage part 736 is provided with an enlarged diameter part 737 so as to have a semi-ellipse shape in which an oblong portion exists in the inclined inner side (left side in the figure) in the direction orthogonal to the rotation center axis line of the cam 731. The oil storage part 736 in parts other than the enlarged diameter part 737 has a slight clearance, and the tappet part 716 is provided.

In the above-described valve drive device, the lubricating oil 719 is extruded from the enlarged diameter portion 737 to the upper surface of the tappet portion 716 when the valve lifter 714 is lifted, and the cam 731 and the tappet portion 716 are in contact with each other. Lubricant 719 is delivered. In addition, the lubricating oil 719 in the enlarged diameter portion 737 is pressurized and scattered by the tappet portion 716 in the high speed rotational speed region. At this time, since the diameter r of the tappet portion 716 is smaller than the diameter R of the base circle of the cam 731, the scattered lubricant oil 719 is directly led to the cam convex portion of the cam 731. Thus, lubrication of the contact portion between the cam 731 and the tappet portion 716 is sufficiently performed.

For this reason, high friction and abrasion do not occur, the output performance and fuel economy of an internal combustion engine improve, and durability reliability is improved.

20 to 24, an eighth embodiment of the present invention will be described. Fig. 20 shows a schematic configuration of a valve drive device according to the eighth embodiment of the present invention. 21 shows a schematic configuration of the valve lifter before the maximum lift, FIG. 22 shows a view taken along line III-III in FIG. 21, FIG. 23 shows a schematic configuration of the valve lifter after the maximum lift, and FIG. 23 is a view taken along the line VV of FIG.

As shown in these figures, the guide hole 806 of the cylinder head 802 is slidably accommodated in the normal guide portion 812 of the valve lifter 811, and the disc is located above the guide portion 812. The upper tappet portion 813 is provided integrally. The diameter R of the tappet portion 813 is larger than the diameter r of the guide portion 812, and the tappet portion 813 is formed to have an umbrella shape on the guide portion 812.

In the tappet portion 813, a portion of the cam 803 in contact with the cam convex portion forms a substantially circular plane, and the tappet portion 813 and the cam convex portion of the cam 803 are in line contact. The position where the valve 807 is fully pressurized, that is, the position at the time of maximum lift of the valve lifter 811 is the state where only the guide portion 812 is accommodated in the guide hole 806 (the tappet portion 816 is a guide hole ( 806) is not accommodated).

Peripheral grooves 814 as elastic deformation promoting portions are formed around the guide portion 812 at the attachment portion of the tappet portion 813, and the guide portion 812 is a guide hole 806. ), The elastic deformation of the guide portion 812 is promoted by the peripheral grooves 814.

In the valve lifter 811 having the above configuration, as shown in FIGS. 21 and 22, the valve lifter is loaded from the start of the lift of the valve lifter 811 to the maximum lift on the tappet part 816 surface on the right side in FIG. 21. The moment acting on 811 is generated in the same direction as the rotational direction of the cam 803. For this reason, the valve lifter 811 inclines to the right side in drawing, and the clearance of the upper right side of the guide part 812 and the guide hole 806 becomes small.

When the posture of the valve lifter 811 is changed by the moment acting in the same direction as the rotation direction of the cam 803, the guide portion 812 is elastic by the peripheral groove 814 provided on the outer periphery of the guide portion 812. It deform | transforms and will be in the state according to the shape of the guide hole 806. For this reason, the lubricating oil between the guide part 812 and the guide hole 806 is not pushed out, oil film formation is maintained, a hitting sound does not generate | occur | produce, the occurrence of abrasion is also suppressed, and it becomes low friction.

As shown in Figs. 23 and 24, after the maximum lift of the valve lifter 811, the moment acting on the valve lifter 811 is loaded because the load is applied on the tappet portion 813 surface on the left side in Fig. 23. It occurs in the opposite direction to the rotation direction of 803. For this reason, the valve lifter 811 is inclined to the left side in the figure, and the clearance at the upper left of the guide portion 812 and the guide hole 806 becomes small.

When the posture of the valve lifter 811 is changed by a moment acting in a direction opposite to the rotational direction of the cam 803, the guide part 812 is moved by the peripheral groove 814 provided on the outer periphery of the guide part 812. It is elastically deformed in the reverse direction as in the case of FIG. 21, and is in the state which follows the shape of the guide hole 806. As shown in FIG. For this reason, the lubricating oil between the guide part 812 and the guide hole 806 is not pushed out, oil film formation is maintained, a hitting sound does not generate | occur | produce, the occurrence of abrasion is also suppressed, and it becomes low friction.

In addition, the peripheral groove 814 constitutes an unprocessed portion of the back surface of the tappet portion 813 and the outer circumferential surface of the guide hole 812 to facilitate the processing of the valve lifter 811. have.

Claims (7)

Poppet valves 105 and 117 installed in the passages 121 and 122 formed in the cylinder heads 111, 211, 311, 411, 511, 611, 711, and 802 of the internal combustion engine and moving in the valve axis direction. , 118, 217, 317, 417, 517, 617, 717, 807 and direct drive valve lifters mounted between cams 102, 212, 312, 412, 512, 631, 731, 803 formed on the camshaft As a valve drive, Guide holes 123, 213, 313, 413, 513, 613, 713 and 806 formed in the cylinder head, An end is coupled to the tappet portion 103, 216, 316, 416, 5 l6, 616, 716, 813 and the tappet portion that are in contact with the cam and are pressed by the cam, and an end portion is attached to the tappet portion by the cam. Is coupled to the guide part 104, 215, 315, 415, 515, 615, 715, 812 that are received in the guide hole so as to slide in the axial direction of the poppet valve in conjunction with the tappet part by the cam. In the valve drive device comprising a direct drive valve lifter (101, 214, 314, 414, 514, 614, 714, 811) with The diameter (r) of the guide portion is formed smaller than the direct hit (R) of the tappet portion, The valve lifter is installed to be inclined in a direction crossing the rotational center axis of the cam with respect to the vertical direction, a virtual circumference extending the diameter of the tappet portion in the axial direction of the tappet valve, and a head bolt for fixing the cylinder head. The valve driving device, characterized in that the bolt seat surface of the installed diameter and superimposed in a plan view. The method of claim 1, And the passage includes at least an intake passage (121) of the internal combustion engine. The method of claim 2, And the camshaft is installed above the cylinder head, one end of the intake passage is opened into the combustion chamber of the internal combustion engine and the other end is opened to the upper surface of the cylinder head. The method of claim 2, And said intake passage has two or more intake passages in each cylinder of said internal combustion engine in a direction orthogonal to the rotational center axis of said cam, and a poppet valve in each of said intake passages. The method of claim 1, And a diameter of the tappet portion is smaller than a diameter of the base circle of the cam. The method of claim 1, An elastic deformation promoting portion 814 is provided to promote the elastic deformation of the guide portion when accommodated in the guide hole of the guide portion. And the elastic deformation promoting part is a groove provided in the circumferential direction of the guide part. The method of claim 6, And the elastic deformation promoting part is provided in the guide part near the boundary between the tappet part and the guide part.