JP4239938B2 - Lubrication system for engine valve system - Google Patents

Description

  The present invention relates to an engine valve operating system in which a tappet is slidably supported on an inner wall facing a valve operating chamber accommodating chamber in a cylinder head, and a pressing force from a cam is applied to the valve via the tappet. The present invention relates to a lubricating device.

The engine valve system is configured to transmit the rotation of the crankshaft to the camshaft side and transmit the pressing force generated by the cam integral with the camshaft to the intake valve and the exhaust valve as the opening / closing driving force using the valve operating member.
Among such engine valve operating systems, for example, a direct acting valve operating apparatus shown in FIG. 5 is known.

  In this direct acting valve operating apparatus, an annular peripheral wall 130 having a guide hole 120 is formed on the inner wall of the valve operating chamber 110 in the cylinder head 100, and a reverse cup-shaped tappet 140 is slid into the guide hole 120. The stem end 151 of the valve 150 is brought into contact with the inner surface of the top wall of the tappet 140. As a result, the pressing force from the cam 160 is applied to the stem end 151 via the tappet 140, thereby opening the valve 150 that is urged to close by the spring 170. Such a direct-acting valve operating device applies a pressing force from the cam 160 to the tappet 140, so that the valve 150 can be prevented from shaking, and the number of sprung members is small, and the engine can be rotated at a high speed. The adoption is increasing.

By the way, the tappet 140 used in the direct acting valve operating device has a reverse cup shape, and there is no oil drop supply from above in the internal space of the tappet 140, and the lower wall of the valve system accommodating chamber 110 in the cylinder head 100 is provided. The scattered oil is only supplied from the upper surface of the upper deck 180 formed.
An example of a technique for improving the lubricity of the outer peripheral surface of a tappet used in a direct acting valve gear is disclosed in Japanese Patent Application Laid-Open No. 8-14021 (Patent Document 1).

JP-A-8-14021

  As described above, the scattered oil supplied to the contact portions between the valve operating members disposed in the internal space of the tappet 140 is the annular peripheral wall 130 of the guide hole 120 that supports the tappet so as to be slidable. Between the lower edge of the upper deck 180 and the upper surface of the upper deck 180 and passes through an opening 190 formed in a substantially annular shape, and the amount of scattered oil passing through the opening 190 is relatively small. There is a problem that the amount of lubricating oil tends to be insufficient. In particular, the gap between the contact portion a where the inner wall surface of the tappet top wall and the stem end 151 are in contact with each other has a small amount of scattered oil, the lubricity of the contact portion a decreases, and wear tends to proceed excessively. Improvement of lubricity is desired.

Although an oil jet device may be used separately, problems such as difficulty in securing a mounting space and an increase in cost are likely to occur. Furthermore, although the technology of Patent Document 1 can improve the lubricity of the outer peripheral wall of the tappet, it cannot improve the lubricity between valve-operating system members arranged in the internal space of the tappet.
The present invention solves the above-described problems, and does not cause problems such as securing a mounting space and increasing costs, and the amount of lubricating oil supplied to the abutting portions between the valve system members in the internal space of the tappet. It is an object of the present invention to provide an engine valve system lubrication device that can suppress wear by relatively increasing the friction.

According to the first aspect of the present invention, the lubrication of the engine valve operating system in which a guide hole for slidably supporting the tappet interposed between the cam and the valve is formed in the inner wall facing the valve operating chamber accommodating chamber of the cylinder head. In the apparatus, a guide hole extending portion is formed below the guide hole by coupling a lower end of an annular peripheral wall forming a part of the inner wall to the upper deck forming the bottom wall of the valve train accommodating chamber. Is formed in the valve system housing chamber, and a pit for allowing the lubricating oil flowing from the valve system housing chamber to flow into the guide hole extending portion through a lateral opening formed in the annular peripheral wall is formed in the upper An oil sump groove extending in the longitudinal direction of the cylinder head is formed in a portion that is formed in the deck and communicates with the lateral opening and that is below the guide hole extending portion and close to the inner side wall. Ri is formed for the bottom of the groove substantially the same height, characterized in that the other portion is formed on a relatively narrowed throttling.

  According to a second aspect of the present invention, in the lubricating system for an engine valve system according to the first aspect, the lower wall of the guide hole extending portion is formed as a spring receiving portion of a spring that applies a valve closing biasing force to the valve. The oil reservoir and the throttle-like lateral opening are disposed around the oil reservoir.

The present invention, by the tappet interposed between the cam and the valve is moved up and down along the guide hole, and increase or decrease the volume of the guide hole extending portion of the lower oil reservoir in communication with the guide hole extending portion Air enters and exits at a high speed through a throttle-shaped lateral opening that has a bottom surface that is substantially the same height as the groove and the other flow path surface is relatively narrow . At that time, the oil on the oil surface facing the lateral opening Is sucked into the guide hole extension along with the high-speed air flow, and the oil in the oil reservoir facing the lateral opening is drawn into the high-speed air flow to become scattered oil, and this is sucked into the guide hole extension along with the high-speed air flow. In addition, the lubricating oil can be easily supplied by reaching the contact parts between the valve system members in the internal space of the tappet, for example, the tappet and the stem end. Furthermore, since the pits form a step between the bottom of the oil sump groove and the sideways opening side and the main bottom side of the upper deck side, this step causes the oil in the valve system storage chamber to pass through the pits and open the sideways opening and each oil. It is possible to facilitate the flow into the pool groove.

  Further, according to the present invention, the oil scattered from the oil reservoir and the throttle-like lateral opening is further promoted by the operation of the spring, so that the valve system members in the internal space of the tappet, for example, between the tappet and the stem end Lubricating oil can be easily supplied to the contact part.

  1, 2 and 3 show an engine 1 equipped with an engine valve system lubrication device A as an embodiment of the present invention. In this engine 1, a lower wall 301 of the cylinder head 3 is overlapped on an upward surface of the cylinder block 2, and each other is integrally fastened by a plurality of head bolts 4 to form a main part of the engine body.

  The engine body is a multi-cylinder engine in which a plurality of cylinders are sequentially arranged in the longitudinal direction X of the cylinder head 3 (the direction perpendicular to the paper in FIGS. 1 and 2). The engine body is formed below the lower wall 301 of the cylinder head 3. Further, a four-valve engine in which a pair of suction and exhaust ports 5 and 6 are formed on a wall fa facing each combustion chamber C (one combustion chamber is shown in FIGS. 1, 2 and 3) is formed. . As shown in FIG. 3, the pair of exhaust ports 6 merge with each other to form a single exhaust port outlet 601. The intake port 5 side also has a single intake port inlet 501 (see FIG. 3). 2).

  The cylinder head 3 includes an upper deck 7 that functions as a plurality of port forming walls and a water jacket forming wall on the upper side of the lower wall 301, and a valve train accommodating chamber 8 is formed on the upper deck 7. The cylinder head 3 is bolted to a head cover (not shown) so that the valve system accommodating chamber 8 is held in a closed space. The valve system accommodating chamber 8 is provided with suction and exhaust valves 9 and 11 for each cylinder. The intake and exhaust valve systems VI and VE to be driven are accommodated.

  The engine 1 is a DOHC engine, and a pair of suction and exhaust camshafts 12 and 13 extending in the longitudinal direction X of the cylinder head 3 (the vertical direction in FIG. Deployed in parallel. The suction and exhaust camshafts 12 and 13 are pivotally supported on the inner wall side of the cylinder head 3 via bearing members 14 and connected to a crankshaft (not shown) via a rotation transmission system (not shown). It is driven to rotate at half the rotational speed of the crankshaft.

The suction and exhaust side valve systems VI and VE shown in FIGS. 1 and 2 are suction, the stem ends 901 and 111 of the exhaust valves 9 and 11 are sucked through the top wall 151 of the tappet 15, and face the exhaust cams 16 and 17. The direct acting valve gear configured as described above is formed.
Here, the intake valve 9 is driven to open and close by the intake side valve member, and the exhaust valve 11 is driven to open and close by the exhaust side valve member, and the same lubrication device is provided. The system VE will be mainly described.

  As shown in FIG. 1, the valve stem 112 of the exhaust valve 11 that opens and closes the exhaust port 6 of the combustion chamber C is slidably supported along the longitudinal direction of the stem on the upper deck 7 side via the valve guide 18. . The stem end 111 at the protruding end of the exhaust valve 11 is covered with an inverted cup-shaped tappet 15 and abuts against a boss portion 152 protruding from the inner wall of the top wall 151 of the tappet 15.

A state in which a pair of annular peripheral walls 21 are integrated with each other at the portions of the upper deck 7 and the inner wall 19 facing the combustion chambers C that constitute the lower wall of the valve train accommodating chamber 8 in the cylinder head 3 (see FIG. 3). ). A guide hole 22 is formed in the pair of annular peripheral walls 21, and an inverted cup-shaped tappet 15 is slidably fitted therein.
An exhaust cam 17 that rotates integrally with the exhaust cam shaft 13 abuts on the top surface of the top wall 151 of the tappet 15 so as to be slidable.

The exhaust valve 11 includes an umbrella 113 that opens and closes the exhaust port 6, and the stem end 111 on the opposite side is configured to receive a biasing force Fc in the valve closing direction of the spring 22 via the retainer 24 and the cotter 25. That is, the cotter 25 divided into two is formed so as to fit into an annular groove near the stem end 111, and the tapered hole 241 at the center of the retainer 24 engages with the tapered surface forming the outer peripheral surface of both cotters 25. As a result, the retainer 24 can be locked via the cotter 25.
The retainer 24 is formed with an annular spring receiving portion 242, and the upper end of the spring 22 that applies the biasing force Fc in the valve closing direction to the exhaust valve 11 is engaged with the annular spring receiving portion 242. The lower end of the spring 22 is in contact with a spring receiving portion 26 formed on the upper deck 7 side.

  As shown in FIGS. 2 and 3, a guide hole 20 is formed in a pair of annular peripheral walls 21 disposed in a valve system accommodating chamber 8 of the cylinder head 3 and opposed to each combustion chamber C. A guide hole extending portion 27 is formed to extend further below the guide hole 20, and a spring receiving portion 26 is formed at the center of the lower wall of each guide hole extending portion 27.

In this way, each annular peripheral wall 21 around each guide hole 20 extends downward so as to cover the guide hole extending portion 27, and is integrally connected to the upper deck 7 and is also integrated to the inner wall 19 of the cylinder head 3. Combined to form a bulging valve support B.
By the way, an oil sump groove 28 extending in the longitudinal direction X of the cylinder head 3 is formed at a portion near the inner wall 19 side of the cylinder head 3 below the guide hole extending portions 27.

The oil reservoir grooves 28 on the lower wall of each guide hole extending portion 27 communicate with each other through a communication hole 29 formed in the annular peripheral wall overlapping portion 21w (see FIG. 3), and on the opposite side to each communication hole 29. A certain outside communicates with the inside of the valve train accommodating chamber 8 via a throttle-like lateral opening 31 formed in each annular peripheral wall 21.
Here, in the vicinity of each annular peripheral wall 21 on the upper deck 7 side, a drop hole 32 opened to the valve train accommodation chamber 8 is formed, and a lateral opening 31 is formed so as to communicate with the drop hole 32. .
Each such oil sump groove 28, the communication hole 29, and the lateral opening 31 have a low surface of substantially the same height, facilitating the flow of oil between them.

  Here, a plurality of ribs 32 and boss portions 33 for fastening the head bolts 4 are formed on the side of the upper deck 7 that forms the bottom wall of the valve train storage chamber 8. The oil reaching the main bottom surface of the bottom wall of the storage chamber 8 is formed so that it can flow into the pit 32. In addition, the bottom surface of each oil sump groove 28 and the sideways opening 31 is formed to be lower by a predetermined amount than the main bottom surface of the upper deck 7 side, and this step (indicated by symbol h in FIG. 1) It is easy for oil 8 to flow into the lateral openings 31 and the oil sump grooves 28 through the pits 32.

  As shown in FIGS. 1 and 2, each lateral opening 31 is formed with a bottom surface f <b> 1 having substantially the same height as each oil sump groove 28 and communication hole 29 (see FIG. 3). The fs and the upper surface fu are formed so as to be relatively narrow, and the flow passage cross-sectional area here is formed as a narrowed portion smaller than other portions. For this reason, when the tappet 15 moves up and down along the guide hole 20 of the annular peripheral wall 21, the volume of the guide hole extending part 27 increases and decreases, and the air passes through the throttle-like lateral opening 31 communicating with the guide hole extending part 27. Will go in and out at high speed. At that time, the oil on the oil surface facing the lateral opening 31 is drawn into the high-speed air flow J to become scattered oil, and when this oil is sucked into the guide hole extending portion 27, the oil in the internal space of the tappet 15 is moved. It is possible to reach the contact portion between the valve system members, for example, the tappet 15 and the stem end 111, to easily supply the lubricating oil to the same part, to suppress wear, and to improve the durability of the valve system member. it can.

In the above description, the exhaust side valve system VE has been mainly described. However, as shown in FIG. 2, the intake side valve system VI has substantially the same configuration and performs the same operation. Then, the overlapping explanation of the valve system VI and the lubrication device on the intake side is omitted.
When the above-described engine 1 is driven, suction is performed by driving the direct-acting valve operating device, and the exhaust valves 9 and 11 are sucked in a rotational region where only the urging force Fc of each spring 22 is received, and the exhaust ports 5 and 6 are closed. Suction is performed against the urging force Fc of the spring 22, and suction and exhaust ports 5 and 6 are opened in a rotation region where the pressing force Fo of the exhaust cams 16 and 17 is received. When the intake and exhaust ports 5 and 6 are opened and closed at an appropriate rotation timing, the engine 1 executes a predetermined combustion cycle in each combustion chamber C to generate an output.

  In such an engine 1, when it is driven, oil is always supplied from the oil circulation system (not shown) to the exhaust camshafts 12 and 13, and the supplied oil sequentially falls on the upper deck 7, and oil (not shown) While flowing to the downstream side, a part flows into the pit 32 and then flows into the lateral opening 31 and the oil sump grooves 28.

  When the tappet 15 moves up and down along the guide hole 20 in such a state, air enters and exits at a high speed through the throttle-shaped lateral opening 31, and the oil on the oil surface facing the lateral opening 31 moves along with the high-speed air flow J. It is repeatedly sucked into the guide hole extending part 27 or blown out to the pit hole 32 side. In this case, the oil sucked into the guide hole extending portion 27 scatters and adheres to the valve system member in the internal space of the tappet 15. Moreover, the displacement action of the spring 22 is also added, and the scattered oil diffuses with the air flow in the internal space of the tappet 15 and sufficiently adheres to the stem end 111, both cotters 25, and the boss portion 152 of the tappet 15. Thus, lubricating oil can be easily supplied to the contact parts between the valve system members, for example, the contact portion between the tappet 15 and the valve end 111, wear can be easily suppressed, and durability of the valve system members can be improved. Can do.

  1 and 2, when the tappet 15 moves up and down along the guide hole 20, the volume of the guide hole extending portion 27 repeatedly increases and decreases so that the throttle-like lateral opening 31 is provided. Air enters and exits at a high speed, but an engine valve system lubrication device A1 as shown in FIG. 4 may be formed. The lubricating device A1 is different from the lubricating device A of the engine valve system of FIGS. 1 and 2 only in that the one valve 35 is additionally attached to the cylindrical annular peripheral wall 21, and the other structure is the same. The explanation of the overlapping part is omitted.

  The engine valve system lubrication device A1 is provided on the inner wall 19 side of the cylinder head 3 from a pair of annular peripheral walls 21 so as to protrude toward the center side of the valve system housing chamber 8 at a portion facing each combustion chamber C. A bulge-shaped valve support B is formed. As indicated by a two-dot chain line in FIG. 3, the one-way valve 35 is mounted on the center-side facing wall of the valve train accommodating chamber 8 of the annular peripheral wall 21.

  As shown in FIG. 4, a valve receiving portion 37 is formed at a portion of the annular peripheral wall 21 facing the center side of the valve train accommodating chamber 8 and facing the guide hole extending portion 27. A vent hole 38 communicating with the guide hole extending portion 27 is formed at the center of 37. The opening of the vent hole 38 in the valve receiving portion 37 is covered with a thin plate valve body 40 joined to the seating surface 39 of the valve receiving portion 37, and the thin plate valve body 40 has an upper portion thereof covered with two bolts 41. It is fastened and connected to the fastening part.

  The thin plate valve body 40 is a heat-resistant and oil-resistant resin thin plate, and is formed so as to be able to contact and separate from the seating surface 39 by elastic deformation thereof. That is, when the tappet 15 moves downward in the guide hole 20 of the annular peripheral wall 21, the guide hole extending portion 27 inside the vent hole 38 becomes positive pressure, and the air elastically deforms the thin plate valve body 40 through the vent hole 38. It is possible to prevent the pressure on the guide hole extending portion 27 side from increasing by pushing open. Conversely, when the tappet 15 moves upward in the guide hole 20, the guide hole extending portion 27 becomes negative pressure, the thin plate valve body 40 is pressed against the seat surface 39, the opening of the vent hole 38 is closed, and the guide hole extending portion The negative pressure on the 27 side can be allowed.

  4, the tappet 15 moves up and down along the guide hole 20 in the annular peripheral wall 21 when the engine is driven. At this time, when the tappet 15 moves downward along the guide hole 20 due to the pressing force of the cam 17, the air in the guide hole extending portion 27 is pressurized and pushes and opens the thin plate valve body 40 through the vent hole 38. Then, the air is discharged to the valve train accommodating chamber 8 which is outside, and a part of the air is also discharged from the lateral opening 31 to the valve train accommodating chamber 8, and at that time, a relatively small amount of oil is blown out to the pit 32.

  On the contrary, when the tappet 15 is moved upward under the pressing force of the spring 22, the air in the guide hole extending portion 27 becomes negative pressure, and the thin plate valve body 40 is sucked into the vent hole 38 side and joined to the seat surface 39. Then close the opening. As a result, the pressure in the guide hole extending portion 27 becomes negative, and air is sucked into the guide hole extending portion 27 only from the throttle-shaped lateral opening 31 at a high speed, and the oil on the oil surface together with the air becomes the guide hole extending portion 27. Splashes in. For this reason, the oil sucked into the guide hole extending portion 27 is sufficiently adhered to the boss portions of the stem end 111, the both cotters 25, and the retainer 24, which are valve operating members in the internal space of the tappet 15. To improve.

In the engine valve system lubrication device of FIG. 4, when the tappet 15 is operated downward, the pressurized air opens and discharges the thin plate valve body 40, so that the cam consumed for pressurization in the guide hole extending portion 27 The rotational energy loss on the shaft side can be reduced.
Moreover, since a relatively small amount of air is discharged from the lateral opening 31, the amount of oil scattering is relatively small, and the amount of oil in the vicinity of the lateral opening 31 can be maintained relatively sufficiently. For this reason, when the tappet 15 is operated upward, the amount of oil on the oil surface facing the sideways opening 31 is relatively sufficiently maintained, so that the amount of scattered oil drawn into the high-speed airflow can be relatively large. Lubricating oil can be easily supplied between valve system members in the internal space of the tappet 15, for example, a contact portion between the tappet 15 and the stem end, wear can be suppressed, and durability of the valve system member is further improved. be able to.

  Although the present invention has been described as being applied to a four-valve type direct acting valve gear, the present invention can be similarly applied to an engine provided with a two-valve type direct acting valve gear.

1 is a cutaway cross-sectional view of a main part of an exhaust side of a cylinder head provided with an engine valve system lubrication device as one embodiment of the present invention. FIG. 2 is a cutaway cross-sectional view of a main part of an upper part of an engine body of an engine including the engine valve system lubrication device of FIG. 1. FIG. 2 is a cutaway cross-sectional view of a main part in a valve system accommodating chamber of a cylinder head provided with the engine valve system lubrication device of FIG. 1. It is a principal part notch sectional drawing of the exhaust side of the cylinder head to which other embodiment of this invention was applied. It is a principal part notched sectional view of the cylinder head with which the conventional direct acting type valve gear apparatus was mounted | worn.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Engine 3 Cylinder head 7 Upper deck 8 Valve system accommodation chamber 11 Exhaust valve 15 Tappet 17 Exhaust cam 19 Inner wall 20 Guide hole 21 Annular peripheral wall 27 Guide hole extending part 28 Oil reservoir groove (oil reservoir)
31 Side opening A Lubricator for engine valve system C Combustion chamber

Claims (2)

In a lubrication device for an engine valve operating system in which a guide hole for slidably supporting a tappet interposed between a cam and a valve is formed on an inner wall facing the valve operating chamber storage chamber of the cylinder head,
A guide hole extending portion is formed below the guide hole by connecting the lower end of the annular peripheral wall around the guide hole to the upper deck that forms a part of the inner wall and forms the bottom wall of the valve train accommodation chamber. ,
A drop hole is formed in the upper deck that is opened to the valve system storage chamber and allows the lubricating oil flowing from the valve system storage chamber to flow into the guide hole extension through a lateral opening formed in the annular peripheral wall. ,
An oil sump groove that extends in the longitudinal direction of the cylinder head is formed at a portion that communicates with the lateral opening and that is at the lower part of the guide hole extension and close to the inner wall,
An engine valve system lubrication device characterized in that the lateral opening has a bottom surface formed substantially at the same height as the oil sump groove and is formed in a throttle shape with the other portions relatively narrow . The lubrication device for an engine valve system according to claim 1,
A low wall of the guide hole extending portion is formed as a spring receiving portion of a spring that applies a valve closing urging force to the valve, and the oil reservoir and a throttle-like lateral opening are arranged around the spring receiving portion. A lubrication system for engine valve systems.

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