WO2022030219A1

WO2022030219A1 - Internal combustion engine

Info

Publication number: WO2022030219A1
Application number: PCT/JP2021/026759
Authority: WO
Inventors: 真佑笠▲崎▼; 正崇内堀
Original assignee: ヤンマーホールディングス株式会社
Priority date: 2020-08-07
Filing date: 2021-07-16
Publication date: 2022-02-10
Also published as: JP2022030417A

Abstract

[Problem] To suppress the generation of fretting between an inner circumferential surface of a valve arm shaft insertion hole in a valve support and an outer circumferential surface of a valve arm shaft. [Solution] The present invention comprises a lubricating oil passage 14b and a valve arm support oil-pouring hole 14e in a valve arm shaft 14 that is penetrated by a valve arm shaft insertion hole 13a provided to a valve arm support 13. The valve arm support oil-pouring hole 14e opens toward the inner circumferential surface of the valve arm shaft insertion hole 13a in the valve arm support 13.

Description

Internal combustion engine

The present invention relates to an internal combustion engine. In particular, the present invention relates to measures for suppressing the occurrence of fretting in the valve train of an internal combustion engine.

Conventionally, as a configuration of a valve operating system of an internal combustion engine as disclosed in Patent Document 1, a configuration in which a valve arm is swingably supported by a valve arm shaft is known. An OHV (Over Head Valve) type internal combustion engine can be mentioned as an example provided with such a valve operating system. Specifically, as a configuration of this type of valve operating system, each of a plurality of valve arm supports arranged in the cylinder row direction is fixed to the upper part of the cylinder head by means such as bolting, and these valve arms are fixed. The valve arm shaft is inserted into the valve arm shaft insertion hole provided in the support. Both ends of the valve arm shaft are bolted (for example, bolted to valve arm supports located at both ends in the cylinder row direction) to prevent rotation.

Further, the valve arm (the valve arm on the intake side and the valve arm on the exhaust side) is swingably supported by the valve arm shaft at the position corresponding to each cylinder between the adjacent valve arm supports. In an OHV type internal combustion engine, one end of a valve arm is connected to the tip of a push rod that reciprocates by receiving power from a crank shaft, and a valve (intake) is connected to the other end of the valve arm. Valve or exhaust valve) is connected. Then, the valve is opened / closed (the operation of opening / closing the intake port or the exhaust port) by swinging the valve arm due to the reciprocating movement of the push rod.

Japanese Unexamined Patent Publication No. 2002-221083

In the above-mentioned valve operating system, it is necessary to insert the valve arm shaft into the valve arm shaft insertion hole provided in the valve arm support at the time of assembling. In order to facilitate this work, the inner diameter of the valve arm shaft insertion hole of the valve arm support is set slightly larger than the outer diameter of the valve arm shaft. Therefore, when the valve arm shaft is inserted into the valve arm shaft insertion hole of the valve arm support, there is a slight clearance between the inner peripheral surface of the valve arm shaft insertion hole and the outer peripheral surface of the valve arm shaft. ing.

Therefore, when the valve arm shaft bends due to the swing of the valve arm due to the reciprocating movement of the push rod, the valve arm shaft moves slightly inside the valve arm shaft insertion hole of the valve arm support (described above). (Move slightly due to the presence of the clearance), which causes reciprocating slip between the inner peripheral surface of the valve arm shaft insertion hole of these valve arm supports and the outer peripheral surface of the valve arm shaft. There is a risk that resulting fretting (surface damage) will occur. This fretting is not preferable because it causes abnormal noise and deterioration of durability.

The present invention has been made in view of this point, and an object thereof is to generate fretting between the inner peripheral surface of the valve arm shaft insertion hole of the valve arm support and the outer peripheral surface of the valve arm shaft. Is to suppress.

The solution of the present invention for achieving the above object is a valve arm support supported by a cylinder head, a valve arm shaft inserted into a valve arm shaft insertion hole provided in the valve arm support, and the valve. It is assumed that the internal combustion engine is equipped with a valve arm that is swingably supported on the arm shaft. The internal combustion engine is provided with a lubricating oil path and a lubrication hole communicating with the lubricating oil path on the valve arm shaft. The lubrication hole is provided at a position corresponding to the valve arm support.

Due to this specific matter, the lubricating oil flowing through the lubricating oil path provided on the valve arm shaft reaches the lubrication hole via this lubricating oil path. Since this lubrication hole is provided at a position corresponding to the valve arm support, the lubricating oil flowing out from this lubrication hole lubricates the inner peripheral surface of the valve arm shaft insertion hole of the valve arm support. That is, the lubricating oil flows into the clearance between the inner peripheral surface of the valve arm shaft insertion hole of the valve arm support and the outer peripheral surface of the valve arm shaft, so that the valve arm shaft is inside the valve arm shaft insertion hole of the valve arm support. Even if the arm moves slightly, the occurrence of fletting is suppressed by lubricating the space between the inner peripheral surface of the valve arm shaft insertion hole of the valve arm support and the outer peripheral surface of the valve arm shaft. become.

Further, a valve for opening and closing the intake port or the exhaust port is connected to one end of the valve arm, and the opening position of the lubrication hole is provided on the valve side.

In order to effectively suppress the occurrence of fretting, the lubricating oil should be supplied to a position on the inner peripheral surface of the valve arm shaft insertion hole of the valve arm support where fretting is particularly likely to occur. Is preferable. When the valve arm swings while being supported by the valve arm shaft, when the valve arm urges the valve to the open side, the valve arm receives a force in the direction opposite to the movement direction of the valve. This force is transmitted from the valve arm to the valve arm shaft, and this valve arm shaft is pressed against the valve side (the side closer to the valve placement position) of the inner peripheral surface of the valve arm shaft insertion hole of the valve arm support. Will be. Therefore, there is a high possibility that fretting will occur at this position. In the present solution, since the lubrication hole is provided at the position on the valve side, which is a region where this fretting is likely to occur, this region can be satisfactorily lubricated, and the occurrence of fretting is effective. Can be suppressed.

Further, the in-head lubricating oil path provided in the cylinder head, the in-support lubricating oil path provided in the valve arm support, the lubricating oil introduction hole provided in the valve arm shaft, and the lubricating oil path are provided. It is communicated.

According to this, the lubricating oil along the in-head lubricating oil path provided in the cylinder head, the in-support lubricating oil path provided in the valve arm support, the lubricating oil introduction hole provided in the valve arm shaft, and the lubricating oil path. Is flowed, and lubricating oil is supplied from this lubricating oil path to the inner peripheral surface of the valve arm shaft insertion hole of the valve arm support via the lubrication hole. Therefore, the inner peripheral surface of the valve arm shaft insertion hole does not require a special pipe (external piping) for supplying lubricating oil toward the inner peripheral surface of the valve arm shaft insertion hole of the valve arm support. It becomes possible to supply the lubricating oil satisfactorily. Therefore, it is possible to reduce the number of parts and simplify the assembly work of the internal combustion engine.

Further, a plurality of the valve arm supports are arranged over the cylinder row direction, and the lubricating oil path in the support is provided in any one of the plurality of valve arm supports.

According to this, it is possible to simplify the processing of the in-head lubricating oil path and the in-support lubricating oil path as compared with the case where the lubricating oil path in the support is provided for each of the plurality of valve arm supports, and the processing cost can be reduced. Can be planned.

Further, the valve arm support includes a plurality of fixing portions fixed to the cylinder head, and the lubricating oil path in the support is offset with respect to the center line connecting the plurality of fixing portions.

According to this, it is possible to sufficiently secure the area forming the lubricating oil path in the support.

In the present invention, the valve arm shaft inserted into the valve arm shaft insertion hole provided in the valve arm support is provided with a lubricating oil path and a lubrication hole, and the lubrication hole is provided at a position corresponding to the valve arm support. .. Therefore, lubricating oil can be supplied to the clearance between the inner peripheral surface of the valve arm shaft insertion hole of the valve arm support and the outer peripheral surface of the valve arm shaft, and inside the valve arm shaft insertion hole of the valve arm support. Even if the valve arm shaft moves slightly, the occurrence of fretting is suppressed by lubricating between the inner peripheral surface of the valve arm shaft insertion hole of these valve arm supports and the outer peripheral surface of the valve arm shaft. can do.

It is sectional drawing of the internal combustion engine which concerns on embodiment. It is a perspective view which shows a part of the valve operating system of an internal combustion engine. It is a perspective view which shows the cross section along the line III-III in FIG. FIG. 3 is a cross-sectional view taken along the line IV-IV in FIG. It is a perspective view which shows the valve arm axis. It is sectional drawing of a valve arm shaft. FIG. 3 is a cross-sectional view taken along the line VII-VII in FIG. It is a bottom view which shows the valve operating system of an internal combustion engine. FIG. 3 is a cross-sectional view taken along the line IX-IX in FIG. FIG. 3 is a cross-sectional view taken along the line XX in FIG. It is a conceptual diagram for demonstrating the supply path of lubricating oil to a valve train.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present embodiment describes a case where the present invention is applied to an in-line 4-cylinder OHV type internal combustion engine (diesel engine).

-Outline configuration of internal combustion engine-
Before explaining the lubrication structure of the valve train, which is a feature of the present embodiment, the schematic configuration of the internal combustion engine according to the present embodiment will be described.

FIG. 1 is a cross-sectional view of the internal combustion engine 1 according to the present embodiment. The internal combustion engine 1 according to the present embodiment is an OHV type engine with four in-line cylinders, but FIG. 1 shows a cross section of one cylinder. In the following, one cylinder will be described, but other cylinders have the same configuration. The internal combustion engine 1 according to the present invention is not limited to that of the present embodiment in terms of the number of cylinders, the cylinder arrangement, and the like.

As shown in FIG. 1, in the internal combustion engine 1 according to the present embodiment, the cylinder head 4 is attached to the upper side of the cylinder block 3 to form the internal combustion engine main body 2, and the lower side of the internal combustion engine main body 2. An oil pan 5 for storing lubricating oil is attached to (the lower side of the cylinder block 3).

A crank shaft 7 extending horizontally along the cylinder row direction is supported at the lower part of the cylinder block 3. A cylinder 10 is formed in the upper part (cylinder head 4 side) in the cylinder block 3, and a piston 8 is slidably fitted in the cylinder 10 in the vertical direction. The piston 8 is connected to the crank shaft 7 via a connecting rod 9, and the crank shaft 7 is rotationally driven as the piston 8 reciprocates in the vertical direction due to the combustion of the air-fuel mixture in the combustion chamber 6.

Further, a bonnet (valve arm case) 11 is attached to the upper side of the cylinder head 4, and the inside of the bonnet 11 is a valve arm chamber 12. The valve arm chamber 12 accommodates a valve operating system. The configuration of this valve train will be described later.

In the combustion chamber 6 formed by the lower surface of the cylinder head 4, the cylinder 10 and the piston 8, the tip (lower end) of the fuel injection valve 18 (shown by a virtual line in FIG. 1) penetrating the cylinder head 4 in the vertical direction ) Is facing.

Further, an intake manifold 19 and an exhaust manifold 20 are connected to the side surface of the cylinder head 4, and the air is supplied into the cylinder by opening the intake valve 15c and the exhaust valve (not shown in FIG. 1). Exhaust gas is discharged from the cylinder by opening the valve.

A fuel injection pump 22 is arranged on the side of the cylinder block 3, and the fuel stored in the fuel tank (not shown) is pressurized by the fuel injection pump 22 and supplied to the fuel injection valve 18. ..

A lubricating oil pump 23 is arranged below the fuel injection pump 22, and the lubricating oil stored in the oil pan 5 is pumped up and supplied to each part through an oil passage (not shown) in the cylinder block 3. Lubricating oil is circulated to lubricate the inside of the internal combustion engine 1.

Further, a cell motor 24 is arranged on the opposite side of the cylinder block 3.

-Structure of valve train-
Next, the configuration of the valve drive system of the internal combustion engine 1 according to the present embodiment will be described.

FIG. 2 is a perspective view showing a part of the valve operating system of the internal combustion engine 1. FIG. 3 is a perspective view showing a cross section taken along the line III-III in FIG. FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG. FIG. 5 is a perspective view showing the valve arm shaft 14.

As shown in these figures, the valve operating system includes valve arm supports 13, 13, 13 fixed to the upper part of the cylinder head 4 by bolting, a valve arm shaft 14 inserted through the valve arm support 13, and a valve arm. It is provided with

valve arms

15, 15, ... On the intake side and

valve arms

16, 16, ... On the exhaust side, which are swingably supported by the shaft 14.

As shown in FIGS. 3 and 4, rib-shaped

support support portions

4a, 4a, 4a extending upward at positions between the cylinders are provided on the upper portion of the cylinder head 4, and these support support portions 4a are provided. , 4a, 4a, valve arm supports 13, 13, 13 are bolted to the upper surface. Further, side supports 17 and 17 (see FIG. 8 which is a bottom view showing the valve operating system) are bolted to the upper surfaces of the vertical walls on both sides of the cylinder head 4 in the cylinder row direction.

As shown in FIG. 4, the valve arm support 13 includes a support main body portion 13b in which a valve arm shaft insertion hole 13a through which the valve arm shaft 14 is inserted is formed, and a cylinder direction from the support main body portion 13b (FIG. The first support leg (fixed portion in the present invention) 13c extending in the right direction in 4) and the second support leg (left direction in FIG. 4) located in the direction opposite to the cylinder direction (left direction in FIG. 4) from the support main body portion 13b. It is provided with a fixed portion) 13d referred to in the present invention.

Bolt insertion holes

13e and 13f extending in the vertical direction are formed in the first support legs 13c and the second support legs 13d, respectively, and bolts B1 and B2 are formed from above with respect to these

bolt insertion holes

13e and 13f. Is inserted, and the bolts B1 and B2 are screwed into the female screw holes 4c and 4d formed in the support support portion 4a of the cylinder head 4, so that the valve arm supports 13, 13 and 13 are supported by the

support support portions

4a and 4a. , 4a, respectively.

Further, a part of the support main body portion 13b and the first support leg 13c of the valve arm support 13 is retracted from the upper surface of the support support portion 4a of the cylinder head 4 (it is a retracted portion 13B retracted upward). In this portion, a space S1 exists between the valve arm support 13 and the cylinder head 4. The head of the head bolt B3 for fastening the cylinder head 4 to the cylinder block 3 is located in this space S1. That is, before bolting the valve arm support 13 to the cylinder head 4, the cylinder head 4 is fastened to the cylinder block 3 by the head bolt B3, and then the valve arm support 13 is attached to the support support portion 4a of the cylinder head 4. By abutting on the top and bolting the first support leg 13c and the second support leg 13d of the valve arm support 13 to the support support portion 4a, the head of the head bolt B3 is positioned in the space S1. ..

Further, as shown in FIG. 8, the side support 17 also has a valve arm shaft insertion hole (not shown), a support main body portion 17b, a first support leg 17c, and a second support leg 17d, similarly to the valve arm support 13. The first support leg 17c and the second support leg 17d are fastened to the upper surface of the vertical wall of the cylinder head 4 by bolts.

When the valve arm supports 13, 13, 13 and the side supports 17, 17 are fixed to the cylinder head 4 as described above, the valve arm shaft insertion holes 13a, of each

valve arm support

13, 13, 13 The valve arm shaft insertion holes of 13a, 13a and the side supports 17, 17 are arranged on the same axis line, and the valve arm shaft 14 is inserted through these valve arm

shaft insertion holes

13a, 13a, 13a.

As shown in FIG. 5,

bolt insertion holes

14a and 14a are formed at both ends of the valve arm shaft 14, and the

bolt insertion holes

14a and 14a of the valve arm shaft 14 are formed in the support main body portion 17b of the side support 17. By inserting the bolt in the state of being aligned with the bolt insertion hole (not shown), the valve arm shaft 14 is supported by the side supports 17 and 17 in a derotated state.

The valve arm shaft 14 is made of a cylindrical rod. Further, inside the valve arm shaft 14, a lubricating oil path 14b (see FIGS. 3 and 4) for flowing lubricating oil is provided from one end to the other end in the direction along the axis of the valve arm shaft 14. It is formed through all over. A sealing member is press-fitted into both ends of the lubricating oil path 14b, whereby both ends of the lubricating oil path 14b are sealed.

The outer diameter of the valve arm shaft 14 is set to be slightly smaller than the inner diameter of the valve arm shaft insertion hole 13a of the valve arm support 13. In other words, the inner diameter of the valve arm shaft insertion hole 13a of the valve arm support 13 is set slightly larger than the outer diameter of the valve arm shaft 14. This is to facilitate the work of inserting the valve arm shaft 14 into the valve arm shaft insertion hole 13a provided in the valve arm support 13 when assembling the valve train. In this way, since the inner diameter of the valve arm shaft insertion hole 13a of the valve arm support 13 is set slightly larger than the outer diameter of the valve arm shaft 14, the valve arm shaft insertion hole 13a of the valve arm support 13 is set. When the valve arm shaft 14 is inserted, there is a slight clearance between the inner peripheral surface of the valve arm shaft insertion hole 13a and the outer peripheral surface of the valve arm shaft 14.

As shown in FIGS. 2 and 3, the valve arm 15 on the intake side and the valve arm 16 on the exhaust side are located between the valve arm supports 13 and 13 adjacent to each other at positions corresponding to each cylinder of the internal combustion engine 1. Further, it is swingably supported by the valve arm shaft 14 between the adjacent valve arm support 13 and the side support 17. That is, one valve arm 15 on the intake side and one valve arm 16 on the exhaust side are arranged between the adjacent valve arm supports 13 and 13 and between the adjacent valve arm supports 13 and the side support 17. It is supported by the valve arm shaft 14 so as to be swingable. Specifically, each of the

valve arms

15 and 16 is also formed with a valve arm shaft insertion hole 15a (see FIG. 9) similar to the valve arm support 13, and the valve arm is formed in the valve arm shaft insertion hole 15a. By inserting the shaft 14, the

valve arms

15 and 16 are swingably supported by the valve arm shaft 14.

The upper ends of the pair of

intake valves

15c and 15c are connected to the end portion of the valve arm 15 on the intake side on the cylinder direction (right direction in FIGS. 4 and 9) via the connecting member 15b. On the other hand, the end portion of the valve arm 16 on the exhaust side on the cylinder direction (right direction in FIGS. 4 and 9) has an upper end of a pair of exhaust valves (not shown) via the connecting member 16b (see FIG. 2). It is connected. Further, the upper end of the push rod 28 is connected to the end portion of each of the

valve arms

15 and 16 on the direction opposite to the cylinder direction (left direction in FIG. 4). As shown in FIG. 1, the lower end of the push rod 28 is in contact with a cam 29a on a cam shaft 29 that rotates with the rotation of the crank shaft 7, and the rotation of the cam 29a causes the push rod 28 to reciprocate substantially up and down. Be moved. Further, valve springs 15d and 16d are arranged around the outer periphery of the valve stem of each valve 15c between the connecting

members

15b and 16b and the cylinder head 4. As a result, when the

valve arms

15 and 16 are pushed by the push rod 28, the

valve arms

15 and 16 rotate around the valve arm shaft 14 to counteract the urging force of the valve springs 15d and 16d and the intake valve 15c and the like. By pushing the exhaust valve downward, the intake port is opened (opening in the intake stroke) and the exhaust port is opened (opening in the exhaust stroke), and when the pressing force from the push rod 28 is released, the valve is opened. The intake valve 15c and the exhaust valve move upward due to the urging force of the

springs

15d and 16d, so that the intake port and the exhaust port are closed.

-Lubrication structure of valve train-
Next, the lubrication structure of the valve train, which is a feature of this embodiment, will be described. FIG. 6 is a cross-sectional view of the valve arm shaft 14. FIG. 7 is a cross-sectional view taken along the line VII-VII in FIG. FIG. 8 is a bottom view showing the valve operating system of the internal combustion engine 1. FIG. 9 is a cross-sectional view taken along the line IX-IX in FIG. Further, FIG. 10 is a cross-sectional view taken along the line XX in FIG.

As shown in FIGS. 5 and 6, the valve arm shaft 14 has a lubricating oil introduction hole 14c, a valve

arm lubrication hole

14d, 14d, ..., A valve arm support lubrication hole, as holes communicating with the above-mentioned lubricating oil path 14b. (Lubrication holes referred to in the present invention) 14e, 14e, 14e are provided. These

holes

14c, 14d, 14d, ..., 14e, 14e, 14e extend along the radial direction of the valve arm shaft 14, the inner end opens to the lubricating oil path 14b, and the outer end is the valve arm shaft 14. It is open to the outer surface. The formation positions of these

holes

14c, 14d, 14d, ..., 14e, 14e, 14e will be described later.

As shown in FIG. 7, inside the second support leg 13d of the valve arm support 13, a lubricating oil path 13g in the support extending in the vertical direction is provided. On the other hand, inside the cylinder head 4, an in-head lubricating oil path 4e communicating with the in-block lubricating oil path 3a (see FIG. 11) formed in the cylinder block 3 is formed. Specifically, in-head lubrication extending in the vertical direction to the support support portion 4a located between the first cylinder and the second cylinder among the plurality of

support support portions

4a, 4a, 4a provided in the cylinder head 4. The oil path 4e is formed. Further, as shown in FIG. 8 (bottom view showing the valve operating system), the lubricating oil path 13g in the support is located between the first cylinder and the second cylinder among the plurality of valve arm supports 13, 13, 13. It is formed on the valve arm support 13A. The second support leg 13d of the valve arm support 13A is provided with an extending portion 13h extending toward the lower side of the axis of the valve arm shaft 14, and the lubricating oil path 13g in the support is the second support. 2 It is formed so as to extend in the vertical direction inside the extending portion 13h of the supporting leg 13d. As a result, the lubricating oil path 13g in the support is arranged at a position offset from the center line L (indicated by the alternate long and short dash line in FIG. 8) connecting the first support leg 13c and the second support leg 13d. Therefore, a region forming the lubricating oil path 13g in the support is sufficiently secured. Then, as shown in FIG. 7, the upper end opening of the lubricating oil path 4e in the head and the lower end opening of the lubricating oil path 13g in the support are aligned. That is, in a state where the valve arm support 13 is fastened to the upper surface of the support support portion 4a, the upper end opening of the lubricating oil path 4e in the head and the lower end opening of the lubricating oil path 13g in the support of the valve arm support 13 communicate with each other and the head. The lubricating oil that has flowed through the inner lubricating oil path 4e flows into the supporting inner lubricating oil path 13g. Here, the structure is such that the in-head lubricating oil path 4e and the in-support lubricating oil path 13g communicate with each other between the first cylinder and the second cylinder, but the in-head lubricating oil path is configured between the other cylinders. The configuration may be such that 4e and the lubricating oil path 13g in the support communicate with each other.

Further, as shown in FIG. 7, the upper end opening of the lubricating oil path 13g in the support of the valve arm support 13 and the lower end opening of the lubricating oil introduction hole 14c of the valve arm shaft 14 are aligned. That is, when the valve arm shaft 14 is inserted into the valve arm shaft insertion hole 13a of the valve arm support 13, the upper end opening of the lubricating oil path 13g in the support of the valve arm support 13 and the lubricating oil introduction hole 14c of the valve arm shaft 14 The lubricating oil that has flowed through the lubricating oil path 13g in the support flows into the lubricating oil path 14b through the lubricating oil introduction hole 14c. In FIGS. 5 and 6, the flow of the lubricating oil flowing from the lubricating oil introduction hole 14c toward the lubricating oil path 14b is indicated by a solid arrow.

The valve arm lubrication hole 14d formed in the valve arm shaft 14 is for supplying oil toward the valve arm shaft insertion holes 15a of the

valve arms

15 and 16, and is an opening at the outer end (opening on the outer surface of the valve arm shaft 14). ) Are opened toward the valve arm shaft insertion holes 15a of the

valve arms

15 and 16, respectively. Specifically, as shown in FIGS. 5, 6 and 9, valve arm lubrication holes 14d are provided at two locations with respect to one valve arm 15 (16). That is, an upper valve arm lubrication hole 14d-1 (see FIG. 9) extending upward from the lubricating oil path 14b and a lower valve arm lubrication hole 14d-2 extending downward from the lubricating oil path 14b are provided. ing. Therefore, the lubricating oil flowing through the lubricating oil path 14b is divided into the upper valve arm lubrication hole 14d-1 and the lower valve arm lubrication hole 14d-2, and the valve arm shaft insertion hole 15a of the valve arm 15 (16). It is supplied between the inner peripheral surface of the valve arm shaft 14 and the outer peripheral surface of the valve arm shaft 14, and lubricates between them. As a result, the

valve arms

15 and 16 supported by the valve arm shaft 14 can be smoothly swung. In FIGS. 5 and 6, the flow of lubricating oil from the valve arm lubrication hole 14d toward the inner peripheral surface of the valve arm shaft insertion hole 15a is indicated by a broken line arrow.

Further, lubricating

oil paths

15e and 15f are provided inside the valve arm 15 (16). Specifically, as shown in FIG. 9, the first lubricating oil path 15e extending toward the cylinder direction (right direction in FIG. 9) in the valve arm 15 is opposite to the cylinder direction in the valve arm 15 (FIG. 9). A second lubricating oil path 15f extending to the left side in No. 9 is provided. In the first lubricating oil path 15e, the lubricating oil supplied between the inner peripheral surface of the valve arm shaft insertion hole 15a of the valve arm 15 and the outer peripheral surface of the valve arm shaft 14 is supplied to the valve arm 15 and the connecting member 15b. Supply toward the connecting part. Further, in the second lubricating oil path 15f, the lubricating oil supplied between the inner peripheral surface of the valve arm shaft insertion hole 15a of the valve arm 15 and the outer peripheral surface of the valve arm shaft 14 is supplied to the valve arm 15 and the push rod 28. Supply toward the connecting part with.

The valve arm support lubrication hole 14e formed in the valve arm shaft 14 supplies oil to the valve arm

shaft insertion holes

13a, 13a, 13a of the valve arm supports 13, 13, 13. As shown in 10, the outer end (opening on the outer surface of the valve arm shaft 14) is opened toward the valve arm shaft insertion hole 13a of the valve arm support 13 (at a position corresponding to the valve arm support 13). Therefore, the lubricating oil that has flowed through the valve arm support lubrication hole 14e through the lubricating oil path 14b is between the inner peripheral surface of the valve arm shaft insertion hole 13a of the valve arm support 13 and the outer peripheral surface of the valve arm shaft 14. It is supplied to and lubricates between them. In FIGS. 5 and 6, the flow of the lubricating oil from the valve arm support lubrication hole 14e toward the inner peripheral surface of the valve arm shaft insertion hole 13a is indicated by a dashed line arrow.

Further, as shown in FIG. 10, the opening position of the valve arm support 13 in the valve arm support lubrication hole 14e toward the inner peripheral surface of the valve arm shaft insertion hole 13a is the inner peripheral surface of the valve arm shaft insertion hole 13a. Of these, the valve 15c is set at a position closer to the arrangement position side (valve side). That is, the valve arm support lubrication hole 14e is formed as a lubricating oil passage slightly inclined upward toward the arrangement position side of the valve 15c.

FIG. 11 is a conceptual diagram for explaining the supply path of the lubricating oil to the valve train. As shown in FIG. 11, the lubricating oil that has passed from the in-block lubricating oil path (main gallery) 3a of the cylinder block 3 to the in-head lubricating oil path 4e of the cylinder head 4 and the in-support lubricating oil path 13g of the valve arm support 13 , It flows into the lubricating oil path 14b from the lubricating oil introduction hole 14c of the valve arm shaft 14. The lubricating oil that has flowed through the lubricating oil path 14b is divided into the valve arm lubrication hole 14d and the valve arm support lubrication hole 14e, and the lubricating oil that has flowed through the valve arm lubrication hole 14d is the valve arm lubrication holes 15 and 16. It is supplied between the inner peripheral surface of the valve arm shaft insertion hole 15a and the outer peripheral surface of the valve arm shaft 14, and lubricates between them. On the other hand, the lubricating oil flowing through the valve arm support lubrication hole 14e is provided on the inner peripheral surfaces of the valve arm

shaft insertion holes

13a, 13a, 13a of the valve arm supports 13, 13, 13 and the outer peripheral surface of the valve arm shaft 14. It will be supplied in between to lubricate between them.

In the prior art, when the valve arm shaft is bent due to the swing of the valve arm due to the reciprocating movement of the push rod, the valve arm shaft is slightly inside the valve arm shaft insertion hole of the valve arm support. It will move (slightly move due to the presence of the clearance mentioned above) between the inner peripheral surface of the valve arm shaft insertion hole of these valve arm supports and the outer peripheral surface of the valve arm shaft. There was a risk that fretting due to the reciprocating slip of the arm would occur.

On the other hand, in the present embodiment, as described above, between the inner peripheral surface of the valve arm

shaft insertion holes

13a, 13a, 13a of the valve arm supports 13, 13, 13 and the outer peripheral surface of the valve arm shaft 14. Lubricating oil can be supplied to the clearance, and even if the valve arm shaft 14 moves slightly inside the valve arm shaft insertion hole 13a of the valve arm support 13, the valve arm shaft insertion of these valve arm supports 13 can be performed. The occurrence of fletting can be suppressed by lubricating the space between the inner peripheral surface of the hole 13a and the outer peripheral surface of the valve arm shaft 14.

Further, as described above, the opening position of the valve arm support 13 in the valve arm support lubrication hole 14e toward the inner peripheral surface of the valve arm shaft insertion hole 13a is the valve of the inner peripheral surface of the valve arm shaft insertion hole 13a. It is set to a position closer to the arrangement position side of 15c (see FIG. 10). In order to effectively suppress the occurrence of fretting, lubricating oil is supplied to a position on the inner peripheral surface of the valve arm shaft insertion hole 13a of the valve arm support 13 where fretting is particularly likely to occur. It is preferable to do so. When the

valve arms

15 and 16 swing while being supported by the valve arm shaft 14, when the

valve arms

15 and 16 urge the valve 15c to the open side, a force in the direction opposite to the moving direction of the valve 15c. Is received by the

valve arms

15 and 16, and this force is transmitted from the

valve arms

15 and 16 to the valve arm shaft 14, and the valve arm shaft 14 is the inner circumference of the valve arm shaft insertion hole 13a of the valve arm support 13. It will be pressed against the surface of the surface closer to the arrangement position side of the valve 15c. Therefore, there is a high possibility that fretting will occur at this position. In the present embodiment, the inner peripheral surface of the valve arm shaft insertion hole 13a of the valve arm support 13, which is a region where this fretting is likely to occur, is directed toward a position closer to the arrangement position side of the valve 15c. Since the valve arm support lubrication hole 14e is opened, this region can be satisfactorily lubricated, and the occurrence of fretting can be effectively suppressed.

Further, in the present embodiment, the in-head lubricating oil path 4e provided in the cylinder head 4, the in-support lubricating oil path 13g provided in the valve arm support 13, and the lubricating oil introduction hole provided in the valve arm shaft 14 are provided. The structure is such that the 14c, the lubricating oil path 14b, and the valve arm support lubrication hole 14e are communicated with each other. Therefore, the inside of the valve arm shaft insertion hole 13a does not require a special pipe (external pipe) for supplying lubricating oil toward the inner peripheral surface of the valve arm shaft insertion hole 13a of the valve arm support 13. It is possible to supply lubricating oil well toward the peripheral surface. Therefore, it is possible to reduce the number of parts and simplify the assembly work of the internal combustion engine 1.

Further, in the present embodiment, the lubricating oil path 13g in the support is provided in the valve arm support 13A of any one of the plurality of valve arm supports 13, 13, 13. Therefore, it is possible to simplify the processing of the in-head lubricating oil path 4e and the in-support lubricating oil path 13g as compared with the case where the in-support lubricating oil path 13g is provided in each of the plurality of valve arm supports 13, 13, 13. , It is possible to reduce the processing cost.

Further, in the present embodiment, the region between the

support legs

13c and 13d of the valve arm support 13 is retracted from the cylinder head 4, and the head bolt B3 is retracted between the retracted portion 13B of the valve arm support 13 and the cylinder head 4. It is inserted from the space S1 of the above to the cylinder head 4 and the cylinder block 3. Therefore, the arrangement position of the head bolt B3 and the arrangement position of the valve arm support 13 can be overlapped in a plan view, and the configuration for fixing the cylinder head 4 to the cylinder block 3 and the lubrication in the head are provided. It is possible to compactly realize a configuration for securing a lubricating oil path extending from the oil path 4e to the lubricating oil path 13g in the support.

-Other embodiments-
It should be noted that the present invention is not limited to the above-described embodiment, and all modifications and applications included in the claims and the range equivalent to the claims are possible.

For example, in the above embodiment, the case where the present invention is applied to the push rod method of the OHV type internal combustion engine has been described, but the present invention is also applied to the finger follower method of the OHC (OverHead Camshaft) type internal combustion engine. It is possible.

This application claims priority based on Japanese Patent Application No. 2020-134452 filed in Japan on August 7, 2020. By reference to this, all its contents are incorporated into this application.

In the present invention, a valve arm support supported by a cylinder head, a valve arm shaft inserted into a valve arm shaft insertion hole of the valve arm support, and a valve arm swingably supported by the valve arm shaft are provided. It can be applied to an internal combustion engine equipped with it.

Claims

It is provided with a valve arm support supported by a cylinder head, a valve arm shaft inserted into a valve arm shaft insertion hole provided in the valve arm support, and a valve arm swingably supported by the valve arm shaft. In an internal combustion engine
The valve arm shaft is provided with a lubricating oil path and a lubrication hole communicating with the lubricating oil path.
The internal combustion engine is characterized in that the lubrication hole is provided at a position corresponding to the valve arm support.
In the internal combustion engine according to claim 1,
A valve that opens and closes the intake port or the exhaust port is connected to one end of the valve arm.
An internal combustion engine characterized in that the opening position of the lubrication hole is provided on the valve side.
In the internal combustion engine according to claim 1 or 2.
The in-head lubricating oil path provided in the cylinder head, the in-support lubricating oil path provided in the valve arm support, the lubricating oil introduction hole provided in the valve arm shaft, and the lubricating oil path are communicated with each other. An internal combustion engine characterized by being lubricated.
In the internal combustion engine according to claim 3,
A plurality of valve arm supports are arranged over the cylinder row direction.
An internal combustion engine characterized in that a lubricating oil path in the support is provided in any one of the plurality of valve arm supports.
In the internal combustion engine according to claim 3 or 4.
The valve arm support includes a plurality of fixing portions fixed to the cylinder head.
The internal combustion engine, characterized in that the lubricating oil path in the support is offset with respect to a center line connecting the plurality of fixed portions.