JPH0240010A - Lubricating device for camshaft bearing of dohc engine - Google Patents

Abstract

PURPOSE:To deaerate communicating passages and oil passages by communicatedly opening the communicating passages to thrust regulating grooves formed on bearings provided on both sides of camshaft gears, and supplying lubricating oil to the bearings and the thrust regulating grooves. CONSTITUTION:Communicating passages 24, 25, 29-35 are communicatedly opened to thrust regulating grooves 17a, 18a, 21a, 23a formed at least on one side of bearings 17, 18, 21, 23 provided on both sides of gears 14 of camshafts 9a-9d. Lubricating oil supplied to oil passages 26, 27 are supplied to the bearings 17, 18, 21, 23 and the thrust regulating grooves 17a, 18a, 21a, 23a through the communicating passages 24, 25, 29-35. Hereby, lubrication of the bearings on both sides of the gears can be performed, and simultaneously deaeration of the communicating passages and the oil passages can be performed at the part of the thrust regulating grooves.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a cam bearing lubrication device for a DOHC engine in which two camshafts are disposed at the head of a cylinder head.

(Prior Art) Conventionally, in DOHC engines, two camshafts are provided on each shaft, and the gears are engaged to drive the gears, and the axial movement of the camshafts is restricted. It has a structure in which a flange is provided, this flange engages with a thrust regulating groove formed in the bearing part of the cylinder head, and oil is supplied to this engagement groove so that the thrust force is absorbed by the hydraulic pressure. , is well known as seen in Japanese Utility Model Application Publication No. 62-76205.

(Problem to be Solved by the Invention) However, in order to lubricate the cam bearings that support the camshafts on both sides in a DOHC engine, the camshafts have a pulley to which a timing belt from the crankshaft is engaged.
The cylinder head part that supports the camshaft is equipped with the drive gear between the camshafts, the valve train cam part, the flange, etc., and the intake and exhaust valves, spark plugs, and head bolts are arranged in relation to the combustion chamber. It forms the bearing part of the camshaft in relation to the camshaft, and its structure is complex. moreover,
In addition to the above structure, it is necessary to provide an oil passage that supplies lubricating oil from the cylinder block to each cam bearing, and an air passage that exhausts the air in the passage when lubricating oil is supplied when the engine starts. It is necessary to provide it in the punched structure,
It is desired to be able to easily configure these structures.

Further, in particular, in a portion where bearings are disposed before and after the drive gear between the camshafts, it may be difficult to form an oil passage due to the shape of the gear, and it is desired to provide bearing lubrication with a simple structure. On the other hand, in an engine such as a V-type engine in which the cylinder axis, that is, the sliding direction of the piston is inclined, it is desirable to form a structure that reduces oil leakage when the engine is stopped.

In view of the above-mentioned circumstances, the present invention provides a cam bearing lubrication device for a DOHC engine, which is capable of lubricating the cam bearings before and after the gears in an engine in which gears are driven between the camshafts, and can obtain the desired effect with a simple structure. The purpose is to

(Means for Solving the Problems) In order to achieve the above object, a cam bearing lubrication device for a DOHC engine according to the present invention has a camshaft provided with a gear for driving between the camshafts, and a gear on both sides in the camshaft direction. A thrust regulating groove is formed in at least one of the bearings, and a small oil passage extending in the camshaft direction is formed in the lower part of the bearing outside the rotation locus of the gear, and this oil passage and the bearings on both sides of the gear are A communication path is provided to communicate between the two parts, and in at least one of the bearings, this communication path is configured to open in communication with the thrust regulating groove.

In addition, in an engine where the cylinder shaft is inclined, a communication passage communicating with the oil passage is formed approximately vertically downward from the cam bearing, and the communication passage of the bearing on the lower side of the slope is set longer than that on the upper side of the slope. The oil passage is formed only on the lower side of the inclination and outside the gear rotation locus.

(Function) In the cam bearing lubricating device as described above, a communication passage is provided between the bearings provided on both sides of the gear of the camshaft from an oil passage formed in the lower part of the bearing outside the rotation locus of the gear. The communication passage is opened to communicate with the thrust regulation groove formed in at least one of the oil passages, and the lubricating oil sent to the oil passage is supplied to the bearing and the thrust regulation groove through the communication passage, thereby lubricating the bearing before and after the gear. The air in the communication passage and oil passage is vented from the thrust regulating groove.

In addition, in a gear drive system between two camshafts disposed at the head of the cylinder head in response to an engine with an inclined cylinder axis, a communication path formed approximately vertically downward from each bearing is The communication passage of the side bearing is set long so that it communicates with the oil passage formed outside the gear rotation locus, and the lubricating oil sent to the oil passage is supplied to the bearing via the vertical communication passage, and the oil passage This ensures that the bearings before and after the gear are lubricated, and the approximately vertical communication path prevents oil from leaking.

(Example) The present invention will be described in detail below with reference to the drawings.

Figure 1 shows a schematic plan view of the cylinder head of a V-type DOHC engine developed in a horizontal state i, '1. ji, FIG. 2 shows its front structure.

A V-type 6-cylinder engine 1 has a right cylinder head 3 and a left cylinder head 4 arranged at an angle on a cylinder block 2 at the lower center, and has three cylinders each with pistons (not shown) sliding at an angle to each other. Right bank R with
and a left bank L are formed. And left bank L
The cylinder row is offset to the front side (downward in FIG. 1) with respect to the cylinder row of the right bank R.

On the upper surface of the cylinder head 3.4, a plug hole 5 is formed approximately at the center corresponding to each cylinder, and each cylinder has an intake valve hole 6.6, into which two intake valves are installed.
Exhaust valve holes 7.7 into which two exhaust valves are installed are respectively opened, and bolt holes 8 into which head bolts for fastening the cylinder heads 3 and 4 to the cylinder block 2 are inserted are arranged at equal intervals. has been done.

The valve operating mechanism disposed above the right and left cylinder heads 3 and 4 for opening and closing the intake and exhaust valves has two camshafts 98 to 9d (second
(see figure) are installed side by side.

It is configured in HC type. Each of the above camshafts 9a to 9d is
It is supported by fastening caps (not shown) to main cam bearings 11 disposed on both left and right sides of the plug hole 5, and the front or rear portion is supported by a front end bearing or a thrust bearing, which will be described later. It is something.

A cam shaft 9a disposed on the right side of the right cylinder head 3 and a cam I+t+9c disposed on the fabric portion of the left cylinder head 3.
A cam pulley 1.2.12 is installed at each front end of the cylinder heads 3, 4 to protrude in front of the cylinder heads 3, 4, and a timing belt 13 is engaged with the cam pulley 1, 2, 12.
, 9c.

Also, both camshafts 9a of each cylinder head 3, 4.

Gears 14 and 14 are fixed to the front end portions of the cylinder heads 3 and 4, and the gears 9b, 9c, and 9d mesh with each other to drive gears between the two camshafts. Gear 1 above
The cylinder heads 3 and 4 at positions corresponding to 4 have gear storage portions 3a and 4 formed larger than the head width of other parts.
A is provided.

Then, the right camshaft 9a in the right cylinder head 3
The front portion is supported by a front end bearing 16 and a thrust bearing 17 provided on both front and rear sides of the gear storage portion 3a in the camshaft direction. On the other hand, the left camshaft 9b in the right cylinder head 3
The front portion is supported by a thrust bearing 18 provided on the rear side of the gear storage portion 3a. Thrust regulation grooves 17a, 1.8a are formed in the thrust bearings 17.18, and flanges 15 (Fig. 4) formed at the rear of the gears 14 of the camshafts 9a, 9b are fitted into these thrust regulation grooves 17a, 18a. axial movement is restricted. In addition, the right camshaft 9
A distributor (not shown) installation portion 3b is formed in the cylinder head 3 at the rear end portion a.

Further, the front part of the right camshaft 9c in the left cylinder head 4 is supported by a front end bearing 20 provided on the front side of the gear storage part 4a.
A thrust bearing 21 is disposed at the rear end of the camshaft. Similarly, the front portion of the left camshaft 9d in the left cylinder head 4 is supported by a front end bearing 22 provided on the front side of the gear storage portion 4a, and a thrust bearing 23 is provided at the rear end of the camshaft. Thrust regulation grooves 21a and 23a are formed in the thrust bearings 21 and 23, and flanges (not shown) formed at the rear ends of the camshafts 9c and 9d are fitted into these thrust regulation grooves 21a and 23a. , axial movement is restricted.

Corresponding to the above cylinder head structure, an oil supply system is formed to lubricate each cam bearing. From each main cam bearing 11 in the right and left cylinder heads 3, 4, outer and inner communication passages 24, 25 are formed, respectively, extending substantially vertically downward (see FIG. 2).
．． The lower end of 25 is connected to outer and inner oil passages 26, 27 extending in the camshaft direction (see FIG. 5).

Camshaft 9a located on the outside of the right and left cylinder heads 3 and 4
, 9d.
is the front end bearing 1 from the rear end to the front end of the cylinder heads 3 and 4.
6.22, and is formed at a position away from the center of the bearing so as to be outside the rotation locus of the gear 14. On the other hand, the right and left cylinder heads 3,
The inner oil passages 27, 27 formed for the camshafts 9b, 9c located inside the cylinder heads 3,
4 extends to the rear of the front gear storage parts 3a, 4a, and is formed at a position close to the center of the bearing so as to be inside the rotation locus of the gear 14.

Note that a machined hole 27a is formed in the front wall on the front extension of the inner oil passage 27, and the front and rear ends of the machined hole 27a and the oil passages 26, 27 are closed by plugs.

At the front end of the outer oil passage 26 in the right cylinder head 3, a front end bearing 1 is provided in front of the gear storage section 3a.
6, a front end communication passage 29 is formed in the same manner as the communication passage 24 to the main cam bearing 11 for each cylinder at the rear, and a front end communication passage 29 is formed for the thrust bearing 17 at the rear of the gear storage section 3a. A communication path 3° is formed in a direction substantially perpendicular to the upper surface of the cylinder head. Furthermore, right cylinder head 3
A communication passage 3] is formed at the front end of the inner oil passage 27 in a direction substantially perpendicular to the upper surface of the cylinder head, with respect to the thrust bearing 18 at the rear of the gear storage portion 3a. On the other hand, at the front end of the outer oil passage 26 in the left cylinder head 4, a communication passage 24 is formed between the front end bearing 22 at the front of the gear storage section 4a and the main cam bearing 11 for each rear cylinder. A long front end communication path 32 is formed, and a long front end communication path 33 is further formed with respect to the front end bearing 20 of the inner bearing portion. Further, at the rear end of the inner and outer oil passages 27.26 of the left cylinder head 4, a communication passage 34.35 is formed in a direction substantially perpendicular to the upper surface of the cylinder head with respect to the rear both thrust bearings 21.23. ing.

As shown in FIGS. 3 and 4, the structure of the communication passages 30, 3 for the thrust bearings 17, 18 (the same applies to 21, 23) is a connection formed on the upper surface of the cylinder head from the oil passages 26, 27. The end of the passage 30.31 opens near the thrust regulating grooves 17a, 18a on the upper surface of the thrust bearing 17.18 of the cylinder head 3, and
7.38, the communicating path 30°31 connects to the recesses 17b and 18b formed continuously with the thrust regulating grooves 17a' and 18a' of the cap 37.38, and the thrust regulating groove 17a , 18a and] 2 communication passages 30.31 are configured to communicate with each other.

Further, the thrust regulating groove is formed on the flange 15 of the camshaft 9a.
A portion 17a on the lower cylinder head 3 side with respect to the width of
18a has a narrow width and is fitted so as to restrict movement in the axial direction, while parts 17a', 1 in the cap 37.38
8a' is formed wider than the flange width so that lubricating oil can flow therethrough, and air can be vented.

In the above structure, as shown in FIG. 2, the upper surfaces of the right and left cylinder heads 3, 4 are formed to be inclined downward from the center toward the outside, and the communication passages 24, 25
, 29.32 are the outer bearings 11, 16.22 on the lower side of the slope.
The outer communication passage 24, 29, 32 for the inner bearing 11 is longer than the inner communication passage 25 for the inner bearing 11 on the inclined upper side. In other words, as shown in Figure 5,
If the inner communication path 25 is formed long, it will interfere with the plug hole 5, and from the viewpoint of securing the plug hole 5, the inner communication path 25 is formed short. And gear 1
The outer oil passage 26 formed on the outer side of the rotation locus of the gear 14 is also formed on the front side of the gear storage portion 3a (4a), and the outer oil passage 26 is A communication passage 29 (32, 33) is provided from the oil passage 26 to lubricate the passage.

In addition, for the above-mentioned inner and outer oil passages 27.26, a sixth
As shown in the figure, an oil introduction passage 4] is formed diagonally upward from an oil introduction port 40 opened at the bottom of the cylinder head 3 (4), and the upper end of this oil introduction passage 41 is connected to the oil introduction port 40 formed at the top of the cylinder head. It opens into chamber 42 . A feed passage 43 communicates with the inner oil passage 27 located directly below the oil chamber 42, and another feed passage 44 communicates with the outer oil passage 26 downward from the oil chamber 42. It is formed.

Then, the lubricating oil pumped from the cylinder block 2
It flows into the oil chamber 42 from the introduction port 40 via the introduction passage 41, is supplied to each of the inner and outer oil passages 27, 26, and is passed through the communication passages 24, 25, 29-35 to each bearing 1.1. ．． 16
~18.20~23 is supplied to perform lubrication. Furthermore, when the engine is stopped, the supply of lubricating oil from the cylinder block 2 is stopped, and the lubricating oil in the introduction passage 41 flows out to the cylinder block 2 side. Oil passage 26.
Lubricating oil remains in the portion 27 to prevent oil from leaking, and the next time the engine is started, lubricating oil can be quickly supplied to the bearing.

In addition, in FIG. 1, 45 is the cylinder head 3, 4
An intake manifold is shown that is disposed between the two and supplies intake air to the cylinders of each cylinder head 3, 4.

According to the embodiment described above, when the front end bearing] 6 and the thrust bearing 17 are arranged before and after the gear 14, the communication passage 29, 30 from the oil passage 26 is opened in the bearing 16, and the thrust regulating groove By having a communication opening in 17a, it is possible to lubricate the front and rear bearings of the gear with a simple structure and to bleed air by using the thrust regulating groove. In addition, in an engine with an inclined cylinder axis such as a V-type engine, communication passages 24 and 25 are formed in a substantially vertical direction to prevent oil leakage, while one communication passage 24 is lengthened to provide a gear rotation trajectory. By communicating with the oil passage 26 on the outside of the gear, it is possible to secure a space for the plug hole 5 and to lubricate the bearing in front of the gear.

In the above embodiment, an example of a V-type 6-cylinder engine was shown, but the same structure as above can also be applied to a DOHC mechanism of a slant engine that is an inline 4-cylinder engine and has an inclined cylinder axis. It is.

(Effects of the Invention) According to the present invention as described above, the communication passage is opened in communication with the thrust regulating groove formed in at least one of the bearings provided on both sides of the gear of the camshaft, and the lubricant is supplied to the oil passage. By supplying oil to the bearing and the thrust regulation groove through the communication passage, it is possible to lubricate the bearings before and after the gear, and to bleed air from the communication passage and the oil passage at the thrust regulation groove. In addition, in an engine with an inclined cylinder axis, the communication passage formed approximately vertically below each bearing is set longer in the bearing on the lower side of the inclination to communicate with the oil passage formed outside the gear rotation trajectory. As a result, an oil passage is secured to lubricate the bearings before and after the gear, and oil leakage can be prevented by the substantially vertical communication passage.

[Brief explanation of the drawing]

Fig. 1 is a schematic plan view showing each cylinder head of a V-type DOHC engine according to an embodiment of the present invention in a horizontally expanded state, Fig. 2 is a front view of the same, and Fig. 3 shows the cylinder head with a bearing cap attached. m-m in Figure 1
4 is a sectional view of the main part taken along the line IV--IV of Fig. 3, which also shows the camshaft. Fig. 5 is a sectional view of the main part taken along the line v-■ of Fig. 1. Figure 6 is the same ■
It is a cross-sectional view along the -■ line. 1...Engine, 3,4...Cylinder head, 3a 4a...Gear storage section, 5...Plug hole, 9a-9d...Camshaft, ]1・・・・・・
・Main cam bearing, 14...Gear, 15...
・Flange, 1.6. 20. 22... Front end bearing, 1.7, 1.8, 2], 2B... Thrust bearing, 17a, 18a, 21a, 23a...
Thrust regulation groove, 1, 7b, 18b... recess,
24.25.29-35...Communication path, 26.2
7...Oil passage, 40...Oil inlet, 41...Oil introduction passage, 42...
・Oil chamber, 43.44...Feeding passage. Diagram

Claims (2)

[Claims] (1) Two camshafts are installed in parallel on the head of the cylinder head,
In a DOHC engine in which gears that mesh with each other are installed on each camshaft to drive gears between both camshafts,
Bearings that support the camshaft on both sides of the gear in the camshaft direction are provided in the cylinder head, and a thrust regulating groove is formed in at least one of the bearings, and a thrust regulating groove is formed in the lower part of the bearing outside the rotational trajectory of the gear in the camshaft direction. A DO characterized in that an oil passage extending from the oil passage to the bearings on both sides of the gear is provided, and in at least one of the bearings, the communication passage is opened to communicate with the thrust regulating groove.
Cam bearing lubrication device for HC engine. (2) The cylinder shaft is inclined, and two camshafts are installed parallel to each other at an angle on the head of the cylinder head corresponding to this cylinder axis, and gears that mesh with each other are installed on each camshaft to provide both cams. In a DOHC engine in which gears are driven between shafts, a bearing for supporting the camshaft is provided in the cylinder head,
A communication passage is formed approximately vertically downward from each bearing, the communication passage of the bearing on the lower side of the slope is set longer than the communication passage on the upper side of the slope, and the oil passage with which the communication passage communicates is connected to the lower part of the bearing. A cam bearing lubrication device for a DOHC engine, characterized in that an oil passage is formed in the axial direction and an oil passage for a camshaft on an inclined downward side is formed outside a gear rotation locus.