JPH06159020A - Valve timing regulating device - Google Patents

Abstract

PURPOSE:To obtain a value timing regulating device to convert the opening and closing timing of the suction valve and the exhaust valve of an internal combustion engine according to the operating condition, in which a hydraulic pressure is fed to a cam journal constantly. CONSTITUTION:To a cam shaft 1, an oil passage 24 communicating to a spool valve 30 communicated to an oil pump 100, through a circular groove 110, an oil passage 23 communicating to the valve 30 through a circular groove 120, and a detour passage 6 communicating to the pump 100 without passing through the valve 30, are provided. Since the hydraulic pressure from the oil pump 100 is fed to a cam journal 200 through the passage for journal lubrication, even when the hydraulic pressure from the spool valve 30 is not fed, the lubrication of the journal 200 can be maintained in a good condition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve timing adjusting device for changing the opening / closing timing of an intake / exhaust valve of an internal combustion engine according to the operating condition.

[0002]

2. Description of the Related Art Conventionally, a "valve timing control device for an internal combustion engine" disclosed in Japanese Patent Laid-Open No. 63-131808 is known as a valve timing adjusting device of this type.

This device is provided with a gear movably provided between the cam pulley and the cam shaft, and by moving the cam pulley and the cam shaft, the gear pulley relatively rotates the cam pulley and the cam shaft to change the opening / closing timing of the valve. . Further, hydraulic chambers are formed in front of and behind the gears, and hydraulic pressure supply means for supplying hydraulic pressure to the two hydraulic chambers via a cam journal portion is provided.

By adjusting the hydraulic pressure supplied to the two hydraulic chambers by the hydraulic pressure supply means, the gear is moved in a desired direction between the cam pulley and the cam shaft, or stopped and held at a desired position. It Thereby, the valve timing is adjusted to a desired timing according to the operating state.

[0005]

In the above prior art, since the hydraulic pressure supply means is communicated with the hydraulic chamber via the cam journal portion, the hydraulic pressure supplied from the hydraulic pressure supply means lubricates the cam journal portion. ing.

However, by stopping the gear at a desired position,
When held at that position, the hydraulic pressures in the two hydraulic chambers may be equalized so that the hydraulic pressure may not be supplied from the hydraulic pressure supply means to the hydraulic chambers. Then, since the hydraulic pressure is not supplied to the cam journal portion, lubrication of the cam journal portion may be insufficient.

In view of the above problems, it is an object of the present invention to provide a valve timing adjusting device which can always supply lubricating oil to a cam journal portion.

[0008]

In order to achieve the above object, the present invention provides a cam shaft provided on a cylinder head, a hydraulic pressure source for generating hydraulic pressure, and a hydraulic pressure source provided on the cam shaft for generating the hydraulic pressure. Valve timing adjusting mechanism for changing valve timing by hydraulic pressure, a cam journal portion of the camshaft, a bearing portion for rotatably supporting the cam journal portion, an outer peripheral surface of the cam journal portion or an inner periphery of the bearing portion. A first annular groove formed on the surface and communicating with the hydraulic source; and a second annular groove formed on the outer peripheral surface of the cam journal portion or the inner peripheral surface of the bearing portion and communicating with the hydraulic source; A first passage formed in the camshaft, one end of which communicates with the advance-side hydraulic chamber of the valve timing adjusting mechanism and the other end of which communicates with the first annular groove; Formed in the camshaft, one end communicates with the retard side hydraulic chamber of the valve timing adjusting mechanism, and a second passage and the other end communicating with the second annular groove,
The hydraulic pressure is provided between the hydraulic pressure source and the first annular groove and between the hydraulic pressure source and the second annular groove to shut off hydraulic pressure supply from the hydraulic pressure source to each of the annular grooves. A valve that adjusts the hydraulic pressure supply from a hydraulic pressure source to each of the annular grooves, and communicates with the hydraulic pressure source, so that the oil leaking between the cam journal portion and the bearing portion due to the hydraulic pressure from the hydraulic pressure source causes the first annular pressure A valve provided with a journal lubrication passage opening to the outer peripheral surface of the cam journal portion or the inner peripheral surface of the bearing portion so as to supply the groove and the second annular groove substantially evenly. A technical means called a timing adjustment device is adopted.

[0009]

According to the structure of the valve timing adjusting device of the present invention described above, the first and second annular grooves formed in the cam journal portion or the bearing portion for rotatably supporting the cam journal portion respectively have the first and second annular grooves. The first and second passages communicate with each other. The first passage communicates with the advance side hydraulic chamber of the valve timing adjusting mechanism provided on the camshaft, and the second passage communicates with the retard side hydraulic chamber. Further, the journal lubrication passage communicates with the hydraulic power source. The passage has an outer peripheral surface of the cam journal portion so that oil leaking between the cam journal portion and the bearing portion due to the hydraulic pressure from the hydraulic source is supplied to the first annular groove and the second annular groove substantially evenly, Alternatively, it is opened in the inner peripheral surface of the bearing portion. Further, a valve is provided between the hydraulic source and the first annular groove and between the hydraulic source and the second annular groove.

When the hydraulic pressure is supplied from the hydraulic pressure source to the first annular groove by the valve, the valve timing adjusting mechanism is controlled to the advance side. On the other hand, the valve allows the second
When hydraulic pressure is supplied to the annular groove, the valve timing adjustment mechanism is controlled to the retard side. Further, when the hydraulic pressure supply from the hydraulic pressure source to each annular groove is cut off by the valve, the operating state of the valve timing adjusting mechanism is maintained in the state when the hydraulic pressure supply was cut off.

In the above operation, when the valve timing adjusting mechanism is controlled to the advance side or the retard side, the oil is supplied between the cam journal portion and the bearing portion by the hydraulic pressure supplied from the hydraulic source. It leaks out of the first or second annular groove. At the same time, oil leaks from the journal lubricating passage between the cam journal portion and the bearing portion. Therefore, the lubrication of the cam journal portion is maintained well. on the other hand,
When the operating state of the valve timing adjusting mechanism is maintained, the hydraulic pressure supply from the hydraulic pressure source to each annular groove is cut off, but the hydraulic pressure from the hydraulic pressure source is supplied from the journal lubrication passage. Therefore, even when the hydraulic pressure supply from the hydraulic pressure source to each annular groove is cut off, oil leaks from the journal lubrication passage between the cam journal portion and the bearing portion.
The lubrication of the cam journal part is kept good.

Further, the journal lubrication passage is provided so that the leaked oil is supplied to the first annular groove and the second annular groove substantially evenly, so that the first and second annular grooves are provided from the respective annular grooves. It is prevented that the operating state of the valve timing adjusting mechanism at this time is changed by the oil flowing into the passage, and the operating state is kept constant.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment to which the valve timing adjusting device of the present invention is applied will be described with reference to FIGS. 1, 2, 3 and 4.

FIG. 1 is a sectional view of the valve timing adjusting device of this embodiment, and FIG. 2 is a sectional view taken along line AA of FIG. Then, FIG. 3 is a view as seen from an arrow B in FIG. 1 when a cam pulley 10, a valve timing adjusting mechanism 9 and a cam shaft 1 described later are removed. Further, FIG. 4 is a view taken in the direction of arrow C in FIG. 3 when the cylinder head 2 described later is removed.

On the cylinder head 2, there is arranged a camshaft 1 having a hole formed at its center. The cam journal portion 200 of the camshaft 1 is rotatably supported between a bearing portion of the cylinder head 2 and a cam cap 3 fixed to the cylinder head 2 by a bolt (not shown).

At the end of the camshaft 1, a cam pulley 10 driven by a crankshaft (not shown) via a timing belt or a chain is rotatably arranged, and a valve timing adjusting mechanism 9 is provided. ing. This valve timing adjusting mechanism 9
Operates according to hydraulic pressure, and cam pulley 10 and cam shaft 1
The valve timing is changed by changing the relative phase with respect to.

The structure of the valve timing adjusting mechanism 9 will be described below. A camshaft sleeve 13 fixed by a pin 80 and a bolt 14 so as to rotate integrally with the camshaft 1 is provided at the end of the camshaft 1. The camshaft sleeve 13 is formed by two substantially cylindrical members 13b and 13c,
The external tooth helical spline 13a is provided on a part of the outer peripheral surface of b.
Are formed. In addition, a hole 1 is formed at the center of the bolt 14.
4a is formed and communicates with the through hole of the camshaft 1.

On the right side of the cam pulley 10 in FIG. 1, a bowl-shaped pulley sleeve 11 is fixed by a pin 82 and a bolt 83 so as to rotate integrally with the cam pulley 10. A hole is formed on the right side of the pulley sleeve 11 in the drawing, and an end plate 84 is attached to this hole. Further, internal tooth helical splines 11 a are formed on a part of the inner peripheral surface of the pulley sleeve 11. The internal tooth helical spline 11a is formed to have a twist angle in the opposite direction to the external tooth helical spline 13a. Either the external tooth helical spline 13a or the internal tooth helical spline 11a may have a twist angle of zero and may be a spline having straight teeth parallel to the axial direction.

A gap is formed in the radial direction between the pulley sleeve 11 and the camshaft sleeve 13, and a substantially cylindrical hydraulic piston 12 is provided in this gap. An inner tooth helical spline 12b that meshes with the outer tooth helical spline 13a of the camshaft sleeve 13 is formed on a part of the inner surface of the hydraulic piston 12, and an inner tooth helical spline of the pulley sleeve 11 is formed on a part of the outer surface. An external tooth helical spline 12a that meshes with 11a is formed. The rotation of the crankshaft 2, which is transmitted to the cam pulley 10 via a timing belt or a chain (not shown) due to the engagement of the splines, is transmitted to the camshaft 1 via the pulley sleeve 11, the hydraulic piston 12, and the camshaft sleeve 13. Transmitted.

A retard side hydraulic chamber 50 is formed on the left side of the hydraulic piston 12 in the drawing, and an advance side hydraulic chamber 60 is formed on the right side of the hydraulic piston 12 in the drawing. The hydraulic piston 12 is axially movable according to the hydraulic pressure supplied to the hydraulic chambers 50 and 60.

Next, a ball 7 is provided at a predetermined position in a through hole formed at the center of the camshaft 1.
The through hole is partitioned by the ball 7. The through hole on the right side of the ball 7 is the oil passage 24, which is the first passage, and the through hole on the left side of the ball 7 is the bypass passage 6. The oil passage 24 has a hole 14 a in the bolt 14.
And the space formed between the end plate 14 and the camshaft sleeve 13 communicates with the advance side hydraulic chamber 60. On the other hand, the bypass passage 6 communicates with an oil pump 100 that pumps the oil in the oil pan 101 via an oil journal (not shown). Further, a passage 24c is formed from the oil passage 24 in the radial direction of the camshaft 1. The passage 24c communicates with the annular groove 110 formed on the outer circumference of the cam journal portion 200 of the camshaft 1.

Further, the camshaft 1 is formed with an oil passage 23 communicating with the retard angle side hydraulic chamber 50.
An annular groove 120 communicating with the oil passage 23 is formed on the outer circumference of the cam journal portion 200.

Further, from the bypass passage 6, the two annular grooves 110, 120 on the outer periphery of the cam journal portion 200 are provided.
An oil passage 6a for journal lubrication is formed between the two.

The cam cap 3 has the annular groove 1
A passage 24b that communicates with 10 and a passage 23b that communicates with the annular groove 120 are formed. Further, a hydraulic pressure supply passage 21b is formed which communicates with the oil pump 100 through a passage formed in the cylinder head 2 and allows the oil pumped from the oil pump 100 to pass therethrough. Further, an oil pressure release passage 22b is formed which returns to the oil pan 101 through the inside of the engine.

A housing 20 is provided on the cam cap 3. The housing 20 is fixed to the cam cap 3 by the bolts 41 and 42 shown in FIG. As shown in FIG. 3, the lengths of the bolts 41 and 42 extend from the housing 20 through the cam cap 3 to the cylinder head 2. As a result, the housing 20 is fastened and fixed to the cam cap 3 and the cylinder head 2. Further, the lower surface of the housing 20 is provided with an escape portion 29 so as not to come into full contact with the upper surface of the cam cap 3.
Is formed. Accordingly, as shown in FIG. 4, the contact portion between the housing 20 and the cam cap 3 has the bolt 41,
42 Since it is only near the tightening portions 26 and 27, even if the lower surface of the housing 20 and the upper surface of the cam cap 3 are distorted, it is possible to prevent the cam journal portion 200 from being distorted during bolt tightening. In the space formed by the escape portion 29, a passage formed in the housing 20 and a passage formed in the cam cap 3 described later are communicated with each other by an elastic material for ensuring the sealing property of the communication portion. A packing 28 is provided.

The housing 20 has a passage 23a communicating with the passage 23b formed in the cam cap 3,
A passage 24a communicating with the passage 24b is formed. Further, the housing 23 is provided with a hydraulic pressure supply passage 21a and a hydraulic pressure release passage 22a which communicate with the hydraulic pressure supply passage 21b and the hydraulic pressure release passage 22b formed in the cam cap 3.
A space is formed in the lower surface of the housing 20 in a portion where the hydraulic pressure supply passages 21a and 21b communicate with each other, and a filter 70 is provided in this space. The filter 70 removes dust and the like contained in the oil pumped from the oil pump 100.

In the housing 20, the hydraulic pressure supply passage 21a, the hydraulic pressure release passage 22a, the passage 23a, and the passage 24a.
A space portion 20a is formed which is open. The spool valve 30 is housed in the space 20a.

Next, based on FIG. 2, this spool valve 30 will be described.
The configuration of will be described. Cylinder 30a of spool valve 30
Is the mounting stay 30b provided integrally with the bolt 4
By being fixed to the housing 20 at 3, it is housed and fixed in the space 20a. In this cylinder 30a,
An intake port 31, discharge ports 32a and 32b, a retard side port 33, and an advance side port 34 are formed. The suction port 31 communicates with the hydraulic pressure supply passage 21a, the discharge ports 32a and 32b communicate with the hydraulic pressure release passage 22a, the retard side port 33 communicates with the passage 23a, and the advance side port 3
4 communicates with the passage 24a. In addition, a spool 30c that slidably moves inside to switch communication between the ports is inserted in the cylinder 30a. A spring 30d for urging the spool 30c is provided at one end of the spool 30c, and a linear solenoid 30e is provided at the other end of the spool 30c. And the spool 30
The electromagnetic force generated in the linear solenoid 30e causes c to move against the biasing force of the spring 30d.

Further, the head cover 5 covering the cylinder head 2 is provided with the packing 4 and the flange portion 3 of the cam cap 3 interposed therebetween.
It is attached to a. The operation of the valve timing adjusting device of this embodiment will be described below.

When it is necessary to change the valve timing to the advance side in accordance with the operating condition, the spool 30c is set to the position shown in FIG.
Move it to the center and lower side, and suction port 31 and advance side port 34
And the discharge port 32a and the retard side port 33 are communicated with each other. As a result, the oil pump 10
The hydraulic pressure from 0 is supplied to the advance side hydraulic chamber 60, and the hydraulic pressure in the retard side hydraulic chamber 50 is released. Therefore, the hydraulic piston 12 moves leftward in FIG. 1, and the camshaft 5 advances relative to the crankshaft 2.

When it is necessary to change the valve timing to the retard side according to the operating state, the spool 30c
2 is moved upward in FIG. 2 so that the suction port 31 and the retard side port 33 communicate with each other and the discharge port 32b and the advance side port 34 communicate with each other. As a result, the oil pressure from the oil pump 100 is supplied to the retard side hydraulic chamber 50, and the hydraulic pressure in the advance side hydraulic chamber 60 is released. Therefore, the hydraulic piston 12 moves to the right in FIG. 1, and the camshaft 5 retards relative to the crankshaft 2.

Further, when it becomes necessary to maintain the valve timing at a desired timing according to the operating state, the spool 30c is closed at both the advance side port 34 and the retard side port 33 (hereinafter, intermediate hold). Called position). As a result, the hydraulic pressures in the hydraulic chambers 50 and 60 become equal, the hydraulic piston 12 does not move, and the rotational phases of the cam pulley 10 and the cam shaft 1 do not change.
Therefore, since the hydraulic piston 12 can be held at a desired position by controlling the spool 30c to the intermediate holding position, the valve timing can be held at a desired timing.

Here, for example, when the spool 30c of the spool valve 30 is moving to the advance side, the oil pump 1
From 00 to the hydraulic chamber 60 on the advance side,
The oil pushed out from the retard angle side hydraulic chamber 60 passes through the cam journal portion 200, so that the lubrication of the cam journal portion 200 becomes good.

Further, when the spool 30c is controlled to the intermediate holding position, the pressure-fed oil is no longer supplied to the cam journal portion 200 from the passage 22a or the passage 23a, but the journal lubricating oil passage 6a is used to feed the oil pump 100. The pumped oil is the cam journal part 20.
Supplied to zero. As a result, the cam journal unit 20
A lubrication of 0 can always be good.

Further, since the journal lubrication oil passage 6a is opened between the annular grooves 110 and 120, the passage 6
The pumped oil from a can flow into the hydraulic chambers 50 and 60 substantially evenly. Therefore, for example, when it is desired to keep the spool 30c at the intermediate holding position, the hydraulic pressure supplied to both hydraulic chambers does not become uneven. Therefore, the controllability of the valve timing does not deteriorate.

Next, a second embodiment is shown in FIG. In addition,
In the second embodiment, the same or equivalent components as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted. As shown in FIG. 4, the left side of the annular groove 110, the annular groove 12
Journal lubrication passages 21 that open to the right of 0 respectively
0b and 210c are formed. Further, when forming such lubrication passages 210b and 210c, it is difficult to process the camshaft 1 so as to communicate with the bypass passage 6 as in the first embodiment. Therefore, as shown in FIG. 4, a passage 210 is formed by branching from the hydraulic pressure supply passage 21a, and the passage 210 and the journal lubrication passage 210b,
210c is connected.

Here, the passages 210b and 210c are formed to have a diameter smaller than the diameter of the passages 24a, 24b, 23a and 23b. As a result, the oil flow rate in the passage is reduced, so that the amount of oil leaking to the cam journal portion 200 can be minimized. Also,
In the case of this embodiment, a throttle 211 is formed in the passage 210 to further reduce the oil flow rate. As a result, the lubrication of the cam journal portion 200 can be always improved, and excess oil can be prevented from flowing into the hydraulic chambers 50 and 60.

The right side of the passage 210b in the figure, 21
The space between the cam journal portion 200 and the bearing portion on the left side in the figure of 0c is open to the atmosphere. Therefore, a part of the pressure-fed oil supplied to the passages 210b and 210c is
It can escape into the engine from between the cam journal portion 200 and the bearing portion. Therefore, the annular groove 11
It is possible to reduce the amount of oil flowing into 0, 120 as much as possible. As a result, the cam journal unit 200
Even in an engine that cannot secure a sufficiently long period, the above configuration can prevent an excessive amount of oil from flowing from the journal lubrication passage into the hydraulic chambers 50 and 60.

[0039]

According to the configuration and operation of the valve timing adjusting device of the present invention described above, even when the communication between the hydraulic power source and the first and second annular grooves is cut off, the passage for journal lubrication is used. Lubrication between the cam journal portion and the bearing portion can always be kept better than the above oil.

Further, since the oil leaking from the journal lubricating passage is supplied to the first annular groove and the second annular groove substantially evenly, the operating state of the valve timing adjusting mechanism at this time should be kept constant. You can

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a valve timing adjusting device of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a view on arrow B of FIG.

FIG. 4 is a view on arrow C in FIG.

FIG. 5 is a cross-sectional view showing another embodiment of the present invention.

[Explanation of symbols]

 1 camshaft 2 cylinder head 3 cam cap 6 detour passage 6a journal lubrication passage 23 oil passage 24 oil passage 30 spool valve 100 oil pump 110 annular groove 120 annular groove 200 cam journal section

Claims (1)

[Claims] 1. A camshaft provided on a cylinder head, a hydraulic pressure source for generating hydraulic pressure, a valve timing adjusting mechanism provided on the camshaft for changing valve timing by hydraulic pressure generated by the hydraulic pressure source, A cam journal portion of the camshaft, a bearing portion that rotatably supports the cam journal portion, and a first annular ring that is formed on an outer peripheral surface of the cam journal portion or an inner peripheral surface of the bearing portion and communicates with the hydraulic power source. A groove, a second annular groove formed on the outer peripheral surface of the cam journal portion or the inner peripheral surface of the bearing portion and communicating with the hydraulic pressure source, and formed in the cam shaft, and one end of which is the valve timing adjusting mechanism. A first passage that communicates with the advance-side hydraulic chamber and has the other end communicating with the first annular groove, and is formed in the camshaft, and has one end formed with the valve. A second passage communicating with the retard angle side hydraulic chamber of the imming adjusting mechanism and having the other end communicating with the second annular groove; between the hydraulic source and the first annular groove; and the hydraulic source and the A valve provided between the hydraulic pressure source and the second annular groove, for interrupting the hydraulic pressure supply from the hydraulic pressure source to each of the annular grooves and adjusting the hydraulic pressure supply from the hydraulic pressure source to each of the annular grooves; The cam so as to supply the oil leaking between the cam journal portion and the bearing portion to the first annular groove and the second annular groove substantially evenly by the hydraulic pressure from the hydraulic source. A valve timing adjusting device comprising: a journal lubrication passage opening to an outer peripheral surface of the journal portion or an inner peripheral surface of the bearing portion.