JP2009228544A - Lubricating device of valve train - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To intermittently flow oil from an oil feeding hole provided to a cam shaft without increasing rotation resistance of the camshaft in a lubricating device of a valve train. <P>SOLUTION: This lubricating device of a valve train comprises a camshaft 1 for driving a valve 14 provided to a cylinder of an internal combustion engine, a plurality of in-shaft oil paths 9A-9C which are provided along a longitudinal direction of the camshaft 1 inside the cam shaft 1 and serve as flow paths for lubricating oil, oil feeding holes 17A-17C opened on an outer periphery of the camshaft 1 and flowing the oil supplied from the in-shaft oil paths 9A-9C to a portion which needs lubrication, and an oil flowing destination switch mechanism for sequentially switching an oil destination among the in-shaft oil paths 9A-9C while the camshaft 1 rotates once. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a lubricating device for a valve operating mechanism.

  As a lubrication device for lubricating a valve operating mechanism of an internal combustion engine, a device employing a lubrication system called a cam shower is known (see, for example, Patent Document 2). In this apparatus, an oil supply pipe is disposed above the camshaft, and oil flows out from an oil supply hole formed in the oil supply pipe toward a contact portion between the cam and the rocker arm.

  The cam shower device is usually provided in a cylinder head cover. For this reason, there exists a fault that a cylinder head cover will become thick and the height of the cylinder axial direction of an engine will become high.

  In recent years, demands for improving fuel efficiency have further increased, and therefore, it is required to make the engine oil pump as small as possible. For this reason, even in a lubrication device of a valve operating mechanism, in order to reduce the flow rate of oil, it is required not to constantly flow out oil from the oil supply hole but to flow out oil only when necessary. In the cam shower device, in order to perform such intermittent oil supply, it is necessary to add a control valve or the like for controlling the flow of oil, which further increases the number of parts and complicates the structure.

  On the other hand, a lubrication device for a valve operating mechanism is known in which a hollow portion provided in a camshaft is used as an oil passage so that oil flows out from an oil supply hole formed in a cam lobe (cam crest). As a modification of this type of lubricating device, Japanese Utility Model Laid-Open No. 63-63514 discloses a device provided with a pipe member for forming an oil passage which is inserted into a hollow portion of a camshaft and fixed at one end to a cylinder head. It is disclosed. In this pipe member, an oil discharge hole is formed at a location where the longitudinal position of the camshaft coincides with the oil supply hole of the cam lobe. Since this pipe member is fixed to the cylinder head as described above, it does not rotate. Therefore, the oil supply hole of the cam lobe and the oil discharge hole of the pipe member communicate (overlap) only once while the camshaft rotates once. With such a configuration, the oil can flow out from the oil supply hole only when the oil supply hole of the cam lobe and the oil discharge hole of the pipe member communicate with each other (that is, only once during one rotation of the camshaft). And the above publication.

Japanese Utility Model Publication No. 63-63514 JP 2006-105023 A

  However, in the conventional lubrication apparatus, the inner peripheral surface of the camshaft hollow portion slides with respect to the outer peripheral surface of the fixed pipe member, and the rotational resistance of the camshaft increases due to the friction. For this reason, there exists a problem that the fuel consumption of an engine deteriorates. In addition, since the oil pumped from the oil pump is always filled inside the pipe member, it is easy for oil to leak into the gap between the outer peripheral surface of the pipe member and the inner peripheral surface of the camshaft hollow portion. It is difficult to completely prevent the oil from being discharged.

  The present invention has been made in view of the above points, and is a valve mechanism that can intermittently flow out oil from an oil supply hole provided in a camshaft without increasing rotational resistance of the camshaft. An object is to provide a lubricating device.

In order to achieve the above object, a first invention is a lubricating device for a valve operating mechanism,
A camshaft for driving a valve provided in a cylinder of the internal combustion engine;
A plurality of oil passages in the shaft that are provided along the longitudinal direction of the camshaft and serve as a flow passage for lubricating oil;
An oil supply hole that opens to the outer peripheral surface of the camshaft and allows oil supplied from the oil passage in the shaft to flow out to a location requiring lubrication,
An oil inflow destination switching mechanism that sequentially switches an oil inflow destination among the plurality of oil passages in the shaft while the camshaft makes one rotation;
It is characterized by providing.

The second invention is the first invention, wherein
Each of the oil supply holes allows oil to flow out only while the oil passage in the shaft communicating with the oil supply hole is an oil inflow destination.

The third invention is the first or second invention, wherein
The oil inflow destination switching mechanism is
An oil inflow portion in which an oil inlet for each of the plurality of oil passages in the shaft is disposed at intervals along the circumferential direction of the camshaft;
An oil supply unit having an oil discharge port provided at a position that can face any of the oil inlets according to the rotational position of the camshaft;
It is characterized by providing.

Moreover, 4th invention is set in 3rd invention,
The oil discharge port is provided on the crankshaft side of the internal combustion engine with respect to the center of the camshaft.

According to a fifth invention, in any one of the first to fourth inventions,
The oil supply hole includes a journal oil supply hole that opens to the outer peripheral surface of the journal of the camshaft,
The clearance between the journal and the bearing is narrow in the direction opposite to the driven node due to the reaction force that the camshaft receives from the driven node,
When the journal oil supply hole is directed in the opposite direction, an oil inflow destination is one of the plurality of oil passages in the shaft that communicates with the journal oil supply hole.

According to a sixth invention, in any one of the first to fifth inventions,
The oil supply hole includes a cam lobe oil supply hole that opens to the outer peripheral surface of the cam lobe of the camshaft,
When the cam lobe oil supply hole faces the direction of the follower node of the cam lobe, the oil passage in the plurality of shaft oil passages that communicates with the cam lobe oil supply hole is an oil inflow destination. To do.

According to a seventh invention, in any one of the first to sixth inventions,
It has a course change part in which the positional relationship of the oil passages in a plurality of shafts in the cross section of the camshaft changes along the longitudinal direction of the camshaft.

The eighth invention is the seventh invention, wherein
The oil supply hole includes a cam lobe oil supply hole that opens to the outer peripheral surface of the cam lobe of the camshaft, and a journal oil supply hole that opens to the outer peripheral surface of the journal of the camshaft.
The course changing portion is provided between the cam lobe oil supply hole and the journal oil supply hole.

The ninth invention is the eighth invention, wherein
The course changing unit is configured to determine a positional relationship of the plurality of oil passages in the shaft in a cross section of the cam shaft between the cam lobe oil supply hole and the journal oil supply hole by approximately 180 ° around the center of the cam shaft. It is characterized by turning.

According to a tenth invention, in any one of the first to fifth inventions,
The oil supply hole includes a journal oil supply hole that opens to the outer peripheral surface of the journal of the camshaft,
A holding unit for holding the journal;
An oil supply passage provided inside the holding portion and supplying oil flowing out from the journal oil supply hole to the cam lobe of the camshaft;
Is further provided.

Further, an eleventh aspect of the invention is any one of the first to tenth aspects of the invention,
In the cross section of the camshaft, the communication portion between the oil passage in the shaft and the oil supply hole is located on the rear end side in the camshaft rotation direction in the cross section of the oil passage in the shaft. .

In addition, a twelfth aspect of the invention is any one of the first to eleventh aspects of the invention,
The camshaft is
A shaft body having a hollow portion;
A partition member which is installed in the hollow portion and forms the plurality of oil passages in the shaft by partitioning the hollow portion into a plurality of spaces in a cross section of the camshaft;
It is characterized by having.

The thirteenth aspect of the invention is any one of the first to eleventh aspects of the invention.
The camshaft is
A shaft body having a hollow portion;
A plurality of pipes installed in the hollow portion and constituting the plurality of shaft internal oil passages;
It is characterized by having.

In addition, a fourteenth invention is according to any one of the first to thirteenth inventions,
The number of oil passages in the shaft is the same as the number of cylinders sharing the camshaft.

According to a fifteenth aspect, in any one of the first to fourteenth aspects,
In the cross section of the camshaft, the plurality of in-shaft oil passages are arranged at equiangular intervals around the center of the camshaft.

  According to the first invention, the oil inflow destination among the plurality of oil passages in the shaft provided inside the camshaft can be sequentially switched while the camshaft makes one revolution. Thereby, oil can be made to flow out intermittently from each oil supply hole. For this reason, since the amount of oil outflow can be reduced, the oil pump capacity can be reduced. Therefore, the driving force consumed by the oil pump is reduced, and the fuel efficiency of the engine can be improved. Further, the rotational resistance of the camshaft does not increase as compared with a normal valve gear.

  According to the second invention, each oil supply hole allows oil to flow out only while the oil passage in the shaft communicating with the oil supply hole is the oil inflow destination. That is, each oil supply hole allows oil to flow out only once during one rotation of the camshaft. For this reason, the amount of oil outflow can be minimized.

  According to the third invention, the oil inflow destination of the plurality of oil passages in the shaft can be switched with a simple structure and with certainty.

  According to the fourth invention, the oil discharge port is provided on the crankshaft side of the internal combustion engine with respect to the center of the camshaft. For this reason, the oil circulation path from the oil pump can be easily connected to the oil discharge port, and the oil circulation path can be simplified.

  According to the fifth aspect of the invention, oil can flow out from the journal oil supply hole only when the journal oil supply hole faces the direction in which the clearance between the journal and the bearing is narrow. For this reason, since the oil outflow amount from the journal oil supply hole is automatically reduced, the oil outflow amount can be further reduced.

  According to the sixth aspect of the invention, oil can flow out from the cam lobe oil supply hole only when the cam lobe oil supply hole faces the direction of the driven node. For this reason, the contact part of a cam lobe and a follower node, the components of a follower node, etc. can be efficiently lubricated with a small amount of oil.

  According to the seventh aspect of the present invention, by providing the course changing portion in which the positional relationship of the plurality of oil passages in the shaft in the cross section of the camshaft changes along the longitudinal direction of the camshaft, each oil supply hole flows out the oil. The direction to be made can be designed in an arbitrary direction.

  According to the eighth aspect of the invention, oil can flow out from the cam lobe oil supply hole and the journal oil supply hole in different directions. For this reason, the oil can be allowed to flow out in an optimum direction by the cam lobe and the journal.

  According to the ninth aspect, oil can flow out from the cam lobe oil supply hole and the journal oil supply hole in directions opposite to each other. Usually, it is most preferable that oil flows out from the cam lobe oil supply hole toward the driven node. On the other hand, the clearance between the journal and the bearing becomes narrower in the direction opposite to the driven node due to the reaction force that the camshaft receives from the driven node. For this reason, if the oil flows out from the journal oil supply hole in the direction opposite to the driven node, the oil outflow amount can be minimized. According to the ninth aspect, both of these two conditions can be satisfied.

  According to the tenth aspect, oil can be supplied to both the journal and the cam lobe with a simple structure.

  According to the eleventh aspect, oil can be allowed to flow out from the oil supply hole by utilizing the inertia force generated by the rotation of the camshaft. For this reason, even in a situation where the oil viscosity is high, such as at an extremely low temperature, the oil can smoothly flow out from the oil supply hole.

  According to the twelfth aspect, a plurality of oil passages in the shaft can be formed in the camshaft with a simple structure.

  According to the thirteenth invention, a plurality of oil passages in the shaft can be formed in the camshaft with a simple structure.

  According to the fourteenth aspect, since the number of oil passages in the shaft is the same as the number of cylinders sharing the camshaft, one oil passage in the shaft is assigned to each oil supply hole for each cylinder. it can. For this reason, the oil outflow direction from each oil supply hole can be optimally designed.

  According to the fifteenth aspect, in the cross section of the camshaft, a plurality of oil passages in the shaft are arranged at equiangular intervals around the center of the camshaft, so that the oil from the oil supply holes of the oil passages in each shaft The outflow amount can be made uniform with high accuracy.

  Embodiments of a lubricating device for a valve operating mechanism according to the present invention will be described below with reference to the drawings. In addition, the same code | symbol is attached | subjected to the element which is common in each figure, and the overlapping description is abbreviate | omitted.

Embodiment 1 FIG.
1 is a longitudinal sectional view of a lubricating device according to a first embodiment of the present invention, FIG. 2 is a transverse sectional view taken along the line II-II in FIG. 1, and FIG. 3 is a cam lobe of the camshaft according to the first embodiment. It is a figure which shows the follower clause. 1 and 2, the lower side is the crankshaft side of the engine.

  The camshaft 1 provided in the lubricating device of the present embodiment shown in FIG. 1 is shared by three cylinders A to C (not shown). That is, the lubrication apparatus of this embodiment is preferably used for a V-type (including a horizontally opposed type, the same applies hereinafter) 6-cylinder engine or an inline 3-cylinder engine. The camshaft 1 drives two valves (intake valves or exhaust valves) per cylinder. That is, the camshaft 1 has two cam lobes (cam crests) 2A for the cylinder A, two cam lobes 2B for the cylinder B, and two cam lobes 2C for the cylinder C. However, in FIG. 1, the cam lobe 2C for the right cylinder C is omitted.

  Although illustration is omitted, when the camshaft 1 is viewed from the axial direction, the cam lobes 2A to 2C are formed in such an orientation that their noses are arranged at equiangular intervals (ie, 120 ° intervals). The cam lobes 2A to 2C may be formed integrally with the camshaft 1, or may be fixed to another part.

  Journals 3 are formed between the cam lobes 2A and 2B and between the cam lobes 2B and 2C, respectively. These journals 3 are supported by bearings 4. A journal 5 is formed at the end of the camshaft 1 on the cam lobe 2A side. The journal 5 is supported by the bearing 6.

  The camshaft 1 includes a shaft body 7 having a cylindrical hollow portion, and a partition member 8 fixed to the shaft body 7 while being inserted into the hollow portion of the shaft body 7. The hollow portion of the shaft body 7 and the partition member 8 are provided over almost the entire length of the camshaft 1.

  As shown in FIG. 2, the cross-sectional shape of the partition member 8 is Y-shaped. This Y-shaped cross-sectional shape is maintained over the entire length of the partition member 8. By such a partition member 8, the hollow portion of the shaft body 7 is equally divided into three spaces of 120 ° with respect to the center. These three elongate spaces serve as oil (lubricating oil) passages, and are hereinafter referred to as in-shaft oil passages 9A to 9C. In the present embodiment, the in-shaft oil passages 9A to 9C are arranged at equiangular intervals around the center of the camshaft 1 in the cross section of the camshaft 1 shown in FIG.

  As shown in FIG. 2, oil inflow ports 10 </ b> A to 10 </ b> C communicating with the in-shaft oil passages 9 </ b> A to 9 </ b> C are opened on the outer peripheral surface of the journal 5. The oil inlets 10A to 10C are arranged at equiangular intervals (that is, 120 ° intervals) along the circumferential direction. An oil discharge port 11 is opened on the inner peripheral surface (sliding surface) of the bearing 6. Oil is pumped to the oil discharge port 11 from an oil pump (not shown) of the engine. The bearing 6 includes a cam carrier 6a and a cam cap 6b.

  When the camshaft 1 rotates, the oil inlets 10A to 10C sequentially face the oil discharge port 11 and communicate with each other. That is, during one rotation of the camshaft 1, the oil inflow ports 10A to 10C communicate with the oil discharge port 11 once each. The oil is pumped to the in-shaft oil passages 9A to 9C only while the oil inflow ports 10A to 10C communicate with the oil discharge port 11.

  For example, in the state shown in FIG. 2, the oil inlet 10 </ b> A communicates with the oil discharge port 11. For this reason, the oil discharged from the oil discharge port 11 flows into the in-shaft oil passage 9A. On the other hand, the oil inlets 10 </ b> B and 10 </ b> C are sealed by the inner peripheral surface (sliding surface) of the bearing 6. For this reason, the oil flow in the shaft oil passages 9B and 9C is stopped.

  Further, when none of the oil inlets 10 </ b> A to 10 </ b> C is opposed to the oil discharge port 11, the oil discharge port 11 is sealed by the outer peripheral surface of the journal 5. For this reason, in this state, the amount of oil flowing out from the oil discharge port 11 is a small amount for lubricating the clearance between the journal 5 and the bearing 6.

  In the present embodiment, the oil discharge port 11 is provided on the crankshaft side of the engine with respect to the center of the camshaft 1. The oil circulation path from the oil pump usually rises from the cylinder block side toward the cylinder head side. For this reason, by arranging the oil discharge port 11 on the crankshaft side, the oil circulation path from the oil pump can be easily connected to the oil discharge port 11.

  As shown in FIG. 3, the rocker arm 12 is installed below the cam lobe 2A (on the crankshaft side). That is, the rocker arm 12 is located on the same side as the oil discharge port 11 with respect to the center of the camshaft 1. The rocker arm 12 is installed so as to be swingable around a base end portion (right end portion in FIG. 3). A roller 13 is installed at the center of the rocker arm 12 so that it can rotate smoothly. This roller 13 is in contact with the cam lobe 2A. The tip of the rocker arm 12 is in contact with the end of a valve stem 15 provided in a valve (intake valve or exhaust valve) 14. The valve 14 is biased by the valve spring 16 in the closing direction, that is, upward in FIG. When the cam lobe 2A rotates and presses the roller 13, the rocker arm 12 rotates downward in FIG. 3, the valve stem 15 is pressed, and the valve 14 is lifted (opened). The above-described rocker arm 12, roller 13, valve 14 and the like are similarly provided for the cam lobes 2B and 2C.

  As shown in FIG. 3, the in-shaft oil passage 9 </ b> A is located on the opposite side of the nose of the cam lobe 2 </ b> A via the center of the camshaft 1. A cam lobe oil supply hole 17A communicating with the in-shaft oil passage 9A is opened in the base circle portion (the side opposite to the nose) of the cam lobe 2A. That is, the cam lobe oil supply hole 17 </ b> A is formed on the same side as the oil inlet 10 </ b> A with respect to the center of the camshaft 1.

  Although not shown, the positional relationship between the cam lobe 2B and the oil passage 9B in the shaft and the positional relationship between the cam lobe 2C and the oil passage 9C in the shaft are the same as described above. A cam lobe oil supply hole 17B communicating with the oil passage 9B is opened, and a cam lobe oil supply hole 17C communicating with the in-shaft oil passage 9C is opened at the base circle portion of the cam lobe 2C.

  As described above, only when the oil inflow port 10A communicates with the oil discharge port 11 during the one rotation of the camshaft 1 (the state shown in FIG. 2). The oil is pumped from the oil discharge port 11. At this time, the cam lobe oil supply hole 17A faces the roller 13 as shown in FIG. When oil from the oil discharge port 11 passes through the oil inlet 10A and is pumped to the oil passage 9A in the shaft, the oil flows out (spouts) from the cam lobe oil supply hole 17A toward the roller 13. This oil can lubricate the contact portion between the cam lobe 2A and the roller 13, the bearing of the roller 13, and the like.

  On the other hand, in a state other than the above, that is, when the cam lobe oil supply hole 17A does not face the roller 13, the oil inlet 10A is sealed by the inner peripheral surface (sliding surface) of the bearing 6. The oil flow in the inner oil passage 9A is stopped. Therefore, in this state, oil does not flow out from the cam lobe oil supply hole 17A.

  As described above, the oil flows out from the cam lobe oil supply hole 17A only when the cam lobe oil supply hole 17A faces the roller 13. Similarly, the oil flows out from the cam lobe oil supply hole 17B only when the cam lobe oil supply hole 17B faces the roller 13, and the cam lobe oil supply hole 17C faces the roller 13 from the cam lobe oil supply hole 17C. Oil spills only when you are. For this reason, according to the lubrication apparatus of this embodiment, when lubricating the contact part of the cam lobes 2A-2C and each roller 13, the bearing of each roller 13, etc., oil does not flow out wastefully. The amount of spillage can be minimized. For this reason, since the oil pump capacity can be reduced, the driving force consumed by the oil pump is reduced, and the fuel efficiency of the engine can be improved. Moreover, the lubrication apparatus can be reduced in size. Further, the rotational resistance of the camshaft 1 does not increase compared to a normal valve gear.

  In the present invention, the cam lobe oil supply holes 17A to 17C may be formed at locations other than the base circle portions of the cam lobes 2A to 2C. However, as in this embodiment, the cam lobe oil supply holes 17 to 17C are cam lobe 2A to 2C. It is preferably formed in a 2C base circle portion. This is because the base circle portion is not hardened and can be easily drilled, and since the stress received from the roller 13 is small, there is little influence even if there is a hole. In the present invention, the holes such as the cam lobe oil supply holes 17A to 17C may be holes formed by casting (holes formed from the beginning by casting).

  Further, in the present embodiment, the case where the number of cylinders sharing the camshaft is three has been described as an example. However, in the present invention, the number of cylinders sharing the camshaft is not particularly limited. (In-line 2-cylinder engine, V-type 4-cylinder engine, etc.) 4 (In-line 4-cylinder engine, V-type 8-cylinder engine, etc.), 5 (In-line 5-cylinder engine, V-type 10-cylinder engine, etc.), 6 (In-line 6-cylinder engine, V-type 12-cylinder engine, or the like).

  In the present invention, the number of oil passages in the shaft may not be the same as the number of cylinders sharing the camshaft, but is preferably the same as in the present embodiment. This is because one in-shaft oil passage can be assigned to each cam lobe oil supply hole for each cylinder.

  In the first embodiment described above, the journal 5 and the bearing 6 are the “oil inflow destination switching mechanism” in the first invention, the journal 5 is the “oil inflow portion” in the third invention, and the bearing 6 is the above-mentioned The roller 3 corresponds to the “oil supply section” in the third invention, and corresponds to the “follower node” in the sixth invention.

Embodiment 2. FIG.
Next, the second embodiment of the present invention will be described with reference to FIG. 4 and FIG. 5. The description will focus on the differences from the first embodiment described above, and the same matters will be described. Simplify or omit.

  4 is a longitudinal sectional view of the lubricating device according to the second embodiment of the present invention, and FIG. 5 is a transverse sectional view taken along line VV in FIG. In FIG. 4, the partition member 8 ′ is represented not by a sectional view but by a side view. The lubricating device of this embodiment is characterized in that oil can be supplied also between the journal 3 and the bearing 4. Since the configurations related to the two journals 3 in FIG. 4 are the same, only the configuration related to the left journal 3 in FIG. 4 will be described below.

  As shown in FIG. 4, journal oil supply holes 18 </ b> A to 18 </ b> C that open to the outer peripheral surface of the journal 3 are formed in the camshaft 1 ′ of the present embodiment. As shown in FIG. 5, the journal oil supply holes 18A to 18C communicate with the in-shaft passages 9A to 9C, respectively. The journal oil supply holes 18A to 18C are arranged at equiangular intervals (that is, 120 ° intervals) along the circumferential direction of the camshaft 1 '. The bearing 4 includes a cam carrier 4a and a cam cap 4b.

  As shown in FIG. 4, the partition member 8 ′ has a shape twisted 180 ° between the cam lobe oil supply hole 17A and the journal oil supply holes 18A to 18C, and the journal oil supply holes 18A to 18C and the cam lobe. It has a shape twisted 180 ° between the oil supply hole 17B. That is, the partition member 8 ′ of the present embodiment has a shape twisted 360 ° between the cam lobe 2 </ b> A and the cam lobe 2 </ b> B.

  Since the partition member 8 ′ has the shape as described above, the positions of the in-shaft oil passages 9A to 9C in the cross section of the camshaft 1 ′ between the cam lobe oil supply hole 17A and the journal oil supply holes 18A to 18C. The relationship turns 180 ° around the center of the camshaft 1. Therefore, the positional relationship between the in-shaft oil passages 9A to 9C in the journal 5 and the cam lobe 2A and the positional relationship between the in-shaft oil passages 9A to 9C in the journal oil supply holes 18A to 18C are opposite to each other by 180 °.

  For example, in the state shown in FIG. 4, the oil inlet 10A faces the crankshaft side. For this reason, in this state, oil is pumped from the oil discharge port 11 to the oil passage 9A in the shaft. On the other hand, in this state, in the cross section at the positions of the journal oil supply holes 18A to 18C, the in-shaft oil passage 9A is on the opposite side to the crankshaft, as shown in FIG. Therefore, the journal oil supply hole 18A faces the side opposite to the crankshaft. At this time, since the oil is pumped into the oil passage 9A in the shaft, the oil flows out from the journal oil supply hole 18A into the gap between the journal 3 and the bearing 4.

  That is, oil flows out from the journal oil supply hole 18A only when the journal oil supply hole 18A faces the opposite side of the crankshaft. Similarly, the oil flows out from the journal oil supply hole 18B only when the journal oil supply hole 18B faces the opposite side of the crankshaft, and from the journal oil supply hole 18C, the journal oil supply hole 18C faces the opposite side of the crankshaft. Oil spills only when facing.

  According to the lubricating device of the present embodiment, oil can be intermittently discharged from each journal oil supply hole 18A to 18C as described above. For this reason, the amount of oil outflow for lubricating between the journal 3 and the bearing 4 can be sufficiently reduced. Furthermore, according to the present embodiment, the amount of oil outflow can be further reduced by allowing oil to flow out only when each of the journal oil supply holes 18A to 18C faces the opposite side of the crankshaft. The reason will be described below.

As described in the first embodiment, the roller 13 is in contact with the camshafts 2A to 2C on the crankshaft side. The biasing force of the valve spring 16 presses the roller 13 toward the camshaft 1 ′ via the rocker arm 12. Therefore, the camshaft 1 ′ is always slightly biased in the direction opposite to the crankshaft because the camshaft 1 ′ always receives a force in the direction opposite to the crankshaft from each roller 13. For this reason, the clearance between the journal 3 and the bearing 4 is narrow in the direction opposite to the crankshaft. That is, L ₁ <L ₂ in FIG. Therefore, each of the journal oil supply holes 18A to 18C causes the oil to flow out to a place where the clearance is small, so that the oil outflow amount automatically decreases.

  In the lubrication device of the present embodiment, the oil supply from the cam lobe oil supply holes 17A to 17C to the roller 13 is performed in the same manner as in the first embodiment.

  As described above, according to the lubricating device of the present embodiment, oil can also be supplied between the journal 3 and the bearing 4 using the in-shaft oil passages 9A to 9C. For this reason, it is not necessary to separately provide an oil supply passage between the journal 3 and the bearing 4, and the lubrication apparatus can be further reduced in size and simplified. Further, since the amount of oil outflow for lubricating between the journal 3 and the bearing 4 can be minimized, the oil pump capacity can be further reduced, and the fuel consumption of the engine can be further improved. .

  In the second embodiment described above, the twisted portion of the partition member 8 ′ (inside the journal 3) corresponds to the “course changing portion” in the seventh, eighth and ninth inventions.

Embodiment 3 FIG.
Next, a third embodiment of the present invention will be described with reference to FIG. 6. The description will focus on differences from the above-described embodiments, and the description of similar matters will be simplified or omitted. To do. FIG. 6 is a longitudinal sectional view of the lubricating device according to the third embodiment of the present invention. In FIG. 6, the partition member 8 ″ is represented by a side view rather than a sectional view.

  As shown in FIG. 6, the camshaft 1 ″ in the lubricating device of the present embodiment is not provided with the cam lobe oil supply holes 17 </ b> A to 17 </ b> C in the cam lobes 2 </ b> A to 2 </ b> C, unlike the embodiment described above. On the other hand, the oil inlets 10A to 10C are formed in the journal 5 at the end portion on the cam lobe 2A side, as in the embodiment described above.

  Further, a through hole 19 that penetrates the journal 5 in the diametrical direction is formed on the end side of the camshaft 1 ″ from the oil inlets 10 </ b> A to 10 </ b> C. The opening of the through hole 19 can be opposed to the oil outlet 11 provided in the bearing 6 together with the oil inlet 10A. Thereby, the oil discharged from the oil discharge port 11 can be pumped to the through hole 19 as well. An oil supply passage 20 for supplying oil to the cam lobe 2 </ b> A adjacent to the bearing 6 is formed in the cam cap 6 b of the bearing 6. When the through hole 19 faces the oil discharge port 11, oil is pumped into the through hole 19. This oil flows through the through hole 19 to the opposite side and flows into the oil supply passage 20. As a result, the oil flows out from the oil supply passage 20 as shown by the arrow in FIG. 6, and falls on the adjacent cam lobe 2A. This oil can lubricate the contact portion between the cam lobe 2A and the roller 13, the bearing of the roller 13, and the like.

  As with the second embodiment, journal oil supply holes 18A to 18C are formed in the journal 3 of the camshaft 1 ″ other than the journal 5. An oil supply passage 21 for supplying oil to the adjacent cam lobes 2 </ b> A to 2 </ b> C is formed in the cam cap 4 b of the bearing 4 that supports the journal 3. Similar to the second embodiment described above, the journal oil supply holes 18A to 18C allow oil to flow out when facing the opposite side of the crankshaft. A part of this oil is supplied to the gap between the journal 3 and the bearing 4, and the rest flows into the oil supply passage 21. As a result, oil flows out from each oil supply passage 21 as shown by the arrows in FIG. 6 and falls on the adjacent cam lobes 2A to 2C. This oil can lubricate the contact portions between the cam lobes 2A to 2C and the roller 13, the bearings of the roller 13, and the like.

  The partition member 8 ″ has a shape twisted by 180 ° between the oil inlets 10 </ b> A to 10 </ b> C and the journal oil supply holes 18 </ b> A to 18 </ b> C adjacent to the cam lobe 2 </ b> A. This is the only twisted portion of the partition member 8 ″, and the other portions have a straight shape. As described above, in this embodiment, the cam lobes 2A to 2C are not provided with the cam lobe oil supply holes 17A to 17C. For this reason, it is not necessary for the cam lobes 2A to 2C and the journal 3 to reverse the positional relationships of the oil passages 9A to 9C in the shaft by 180 °. Therefore, the shape of the partition member 8 '' can be simplified as described above.

  As described above, according to the present embodiment, oil can be intermittently supplied to the cam lobes 2A to 2C and the journals 3 and 5 using the in-shaft oil passages 9A to 9C. Therefore, the oil outflow amount can be sufficiently reduced, and the oil pump capacity can be reduced. For this reason, the fuel consumption of the engine can be improved. Further, the lubrication apparatus can be reduced in size and simplified. Furthermore, since the partition member 8 ″ is less twisted and the cam lobe oil supply holes 17 </ b> A to 17 </ b> C are unnecessary, the manufacturing cost can be reduced.

  In the third embodiment described above, the twisted portion (inside the journal 3) of the partition member 8 ″ is the “route changing portion” in the seventh invention, and the cam cap 4b is “ The oil supply passage 21 corresponds to the “holding portion” and corresponds to the “oil supply passage” in the tenth aspect of the present invention.

  Hereafter, the modification of this invention is demonstrated sequentially. The following modifications can be applied in common to the first to third embodiments.

  In the modification shown in FIG. 7, in the cross section of the camshaft 1, the communication points between the shaft oil passages 9 </ b> A to 9 </ b> C and the journal oil supply holes 18 </ b> A to 18 </ b> C It is located on the rear end side of the shaft rotation direction. This has the following advantages. When the viscosity of the oil is high, such as at an extremely low temperature, the oil outflow resistance from the journal oil supply holes 18A to 18C may be large. On the other hand, when the camshaft 1 rotates in the direction of the arrow in FIG. 7, the inertia force in the opposite direction acts on the oil in each of the oil passages 9A to 9C in the shaft. According to the above configuration, even when the oil outflow resistance is large, the oil flows out from the journal oil supply hole 18A by utilizing the inertia force as shown by the arrow of the oil passage 9A in the shaft in FIG. It can be made easy. For this reason, oil can be reliably supplied by a lubrication part. Moreover, since the pressure in the shaft oil passages 9A to 9C can be reduced, the oil pump capacity can be further reduced. The cam lobe oil supply holes 17A to 17C may also be arranged in the same manner as described above.

  8 to 10 are views showing modified examples of the partition member. The partition member may have any configuration as long as the hollow portion of the shaft body 7 can be partitioned into a predetermined number of oil passages in the shaft. For example, when the number of the oil passages in the shaft is three, it may have a substantially equilateral triangular cross-sectional shape like the partition member 22 shown in FIG. Further, when the number of oil passages in the shaft is four, the cross-sectional shape of the partition member can be the shape shown in FIG. 9 or can be substantially square. When the number of oil passages in the shaft is 6, the cross-sectional shape of the partition member can be the shape shown in FIG.

  11 and 12 are diagrams showing a modification of the method for forming the oil passage in the shaft. In the camshaft 1 shown in FIG. 11, pipes 23 </ b> A to 23 </ b> C are installed in the hollow portion of the shaft main body 7, and the insides of these pipes 23 </ b> A to 23 </ b> C serve as in-shaft oil paths 9 </ b> A to 9 </ b> C. Further, in the camshaft 1 shown in FIG. 12, the in-shaft oil passages 9A to 9C are formed by cutting a solid base material. The camshaft 1 as shown in FIG. 12 can also be manufactured by casting.

It is a longitudinal cross-sectional view of the lubricating device of Embodiment 1 of this invention. It is a cross-sectional view in the II-II line in FIG. It is a figure which shows the cam lobe of the cam shaft in Embodiment 1, and its follower. It is a longitudinal cross-sectional view of the lubricating device of Embodiment 2 of this invention. It is a cross-sectional view in the VV line in FIG. It is a longitudinal cross-sectional view of the lubricating device of Embodiment 3 of this invention. It is a figure for demonstrating the modification of this invention. It is a figure for demonstrating the modification of this invention. It is a figure for demonstrating the modification of this invention. It is a figure for demonstrating the modification of this invention. It is a figure for demonstrating the modification of this invention. It is a figure for demonstrating the modification of this invention.

Explanation of symbols

1, 1 ′, 1 ″ Camshaft 2A, 2B, 2C Cam Rob 3, 5 Journal 4, 6 Bearing 7 Shaft body 8, 8 ′, 8 ″ Partition member 9A, 9B, 9C Shaft oil passages 10A, 10B, 10C Oil inlet 11 Oil outlet 12 Rocker arm 13 Roller 14 Valve 15 Valve stem 16 Valve springs 17A, 17B, 17C Cam lobe oil supply holes 18A, 18B, 18C Journal oil supply holes 19 Through holes 20, 21 Oil supply passages 22 Partition members 23A to 23A 23C pipe

Claims (15)

A camshaft for driving a valve provided in a cylinder of the internal combustion engine;
A plurality of oil passages in the shaft that are provided along the longitudinal direction of the camshaft and serve as a flow passage for lubricating oil;
An oil supply hole that opens to the outer peripheral surface of the camshaft and allows oil supplied from the oil passage in the shaft to flow out to a location requiring lubrication,
An oil inflow destination switching mechanism that sequentially switches an oil inflow destination among the plurality of oil passages in the shaft while the camshaft makes one rotation;
A lubrication device for a valve operating mechanism comprising:   2. The lubricating device for a valve operating mechanism according to claim 1, wherein each of the oil supply holes allows oil to flow out only while an oil passage in the shaft communicating with the oil supply hole is an oil inflow destination. The oil inflow destination switching mechanism is
An oil inflow portion in which an oil inlet for each of the plurality of oil passages in the shaft is disposed at intervals along the circumferential direction of the camshaft;
An oil supply unit having an oil discharge port provided at a position that can face any of the oil inlets according to the rotational position of the camshaft;
The lubricating device for a valve operating mechanism according to claim 1 or 2, further comprising:   4. The lubrication device for a valve operating mechanism according to claim 3, wherein the oil discharge port is provided on the crankshaft side of the internal combustion engine with respect to the center of the camshaft. The oil supply hole includes a journal oil supply hole that opens to the outer peripheral surface of the journal of the camshaft,
The clearance between the journal and the bearing is narrow in the direction opposite to the driven node due to the reaction force that the camshaft receives from the driven node,
2. The oil inflow destination of the plurality of oil passages in the shaft, which is connected to the journal oil supply hole, when the journal oil supply hole faces in the opposite direction. The lubrication device for a valve operating mechanism according to any one of claims 1 to 4. The oil supply hole includes a cam lobe oil supply hole that opens to the outer peripheral surface of the cam lobe of the camshaft,
When the cam lobe oil supply hole faces the direction of the follower node of the cam lobe, the oil passage in the plurality of shaft oil passages that communicates with the cam lobe oil supply hole is an oil inflow destination. The lubricating device for a valve operating mechanism according to any one of claims 1 to 5.   7. The route changing portion according to claim 1, further comprising: a course changing portion in which a positional relationship between the plurality of oil passages in the shaft in a cross section of the camshaft changes along a longitudinal direction of the camshaft. Lubricating device of the valve mechanism. The oil supply hole includes a cam lobe oil supply hole that opens to the outer peripheral surface of the cam lobe of the camshaft, and a journal oil supply hole that opens to the outer peripheral surface of the journal of the camshaft.
8. The lubrication device for a valve operating mechanism according to claim 7, wherein the course changing portion is provided between the cam lobe oil supply hole and the journal oil supply hole.   The course changing unit is configured to determine a positional relationship of the plurality of oil passages in the shaft in a cross section of the cam shaft between the cam lobe oil supply hole and the journal oil supply hole by approximately 180 ° around the center of the cam shaft. The lubricating device for a valve mechanism according to claim 8, wherein the lubricating device is swiveled. The oil supply hole includes a journal oil supply hole that opens to the outer peripheral surface of the journal of the camshaft,
A holding unit for holding the journal;
An oil supply passage provided inside the holding portion and supplying oil flowing out from the journal oil supply hole to the cam lobe of the camshaft;
The lubrication device for a valve mechanism according to any one of claims 1 to 5, further comprising:   In the cross section of the camshaft, the communication portion between the oil passage in the shaft and the oil supply hole is located on the rear end side in the camshaft rotation direction in the cross section of the oil passage in the shaft. The lubricating device for a valve operating mechanism according to any one of claims 1 to 10. The camshaft is
A shaft body having a hollow portion;
A partition member which is installed in the hollow portion and forms the plurality of oil passages in the shaft by partitioning the hollow portion into a plurality of spaces in a cross section of the camshaft;
The lubricating device for a valve operating mechanism according to any one of claims 1 to 11, wherein: The camshaft is
A shaft body having a hollow portion;
A plurality of pipes installed in the hollow portion and constituting the plurality of shaft internal oil passages;
The lubricating device for a valve operating mechanism according to any one of claims 1 to 11, wherein:   14. The lubricating device for a valve operating mechanism according to claim 1, wherein the number of oil passages in the shaft is the same as the number of cylinders sharing the camshaft.   The cross-section of the camshaft, wherein the plurality of in-shaft oil passages are arranged at equiangular intervals around the center of the camshaft. Lubricating device for valve mechanism.

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