JPH11159308A - Valve opening/closing timing controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve responsiveness in changing a phase to an advancing direction in a simple structure. SOLUTION: A valve opening/closing timing controller, which has a fluid pressure chamber R0 formed between a rotation transmitting member (an external rotor 30) and a shaft (an internal rotor 20) and divided into an advancing oil chamber R1 and a lagging oil chamber R2 with a vane 60, and first and second fluid passages 12, 13 to supply and discharge fluid into/from the advancing chamber R1 and the lagging chamber R2, is used to control the opening/ closing timing of an intake valve or an exhaust valve for an internal combustion engine. At least one of the lagging chamber is shut off the second fluid passage to be open to the atmosphere.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve timing control device for controlling the timing of opening or closing an intake valve or an exhaust valve in a valve train of an internal combustion engine.

[0002]

2. Description of the Related Art As one type of a valve opening / closing timing control device, a rotary shaft for valve opening / closing is provided so as to be relatively rotatable within a predetermined range, and a rotary power from a crank sprocket or pulley of a crankshaft is transmitted. A transmission member, six vanes attached to the rotation shaft, and an advancing chamber and a retarding chamber formed by the vane formed between the projection provided on the rotation transmission member and the rotation shaft. A fluid passage provided with six fluid pressure chambers, a first fluid passage for supplying and discharging the fluid to the advance chamber, and a second fluid passage for supplying and discharging the fluid to the retard chamber. For example, it is disclosed in JP-A-1-92504 and JP-A-2-50105.

In the valve timing control devices disclosed in the above publications, the working fluid is supplied to the advance chamber through the first fluid passage, and the working fluid is supplied from the retard chamber through the second fluid passage. By discharging the hydraulic oil, the rotation shaft rotates in the advance direction with respect to the rotation transmitting member, the valve opening / closing timing is advanced, and the hydraulic fluid is supplied to the retarding chamber through the second fluid passage and By discharging the hydraulic oil from the advance chamber through one fluid passage, the rotation shaft rotates in the retard direction with respect to the rotation transmitting member, and the valve opening / closing timing is delayed.

[0004]

By the way, during normal operation of the internal combustion engine, a fluctuating torque acts on the rotating shaft, and a torque on the retarding side always acts on the rotating shaft. For this reason, at the time of the above-mentioned phase conversion of the advance and the retard, the rotational force in the advance direction (the pressing force by the advance hydraulic pressure in the advance chamber).
Is smaller than the rotational force in the retard direction (the force obtained by adding the torque generated on the rotating shaft to the pressing force of the retard chamber for the retard hydraulic pressure).

However, in the valve opening / closing timing control device disclosed in the above-mentioned publication, since the same number of advance chambers and retard chambers are provided, only the torque generated on the rotating shaft is required.
There is a possibility that the responsiveness at the time of movement in the advance direction may be lower than that in the retard direction.

Therefore, an object of the present invention is to improve responsiveness at the time of phase conversion in the advance angle direction with a simple configuration.

[0007]

Means for Solving the Problems The technical means of the present invention taken to solve the above problems is a rotating shaft for opening and closing a valve rotatably mounted on a cylinder head of an internal combustion engine, and a rotating shaft for the valve. A rotation transmission member which is provided so as to be relatively rotatable in a predetermined range and transmits rotation power from a crankshaft, a plurality of vanes attached to one of the rotation shaft or the rotation transmission member, and the rotation transmission shaft and the rotation. A plurality of fluid pressure chambers formed between the transmission member and divided into an advancing chamber and a retarding chamber by the vane, and a first fluid passage for supplying and discharging fluid to each of the advancing chambers; A second fluid passage that supplies and discharges fluid to each of the retard chambers, the valve being used to control the opening and closing timing of an intake valve or an exhaust valve of the internal combustion engine. At least one of the corner chambers is connected to the second fluid passage. And al interrupted, it is that was open to the atmosphere.

According to the above-described means, since at least one of the retard chambers is cut off from the second fluid passage and opened to the atmosphere, the rotational force in the advance direction (the advance force in each advance chamber) is increased. Rotational force in the retard direction (the force obtained by adding the torque generated on the rotating shaft to the retarding hydraulic pressure of each retarding chamber) that opposes the angular hydraulic pressure) is reduced, and Responsiveness at the time of phase conversion is improved.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a valve timing control apparatus according to the present invention will be described below with reference to the drawings.

One embodiment of the valve timing control apparatus shown in FIGS. 1 and 2 is a camshaft 10 rotatably supported by a cylinder head 70 of the internal combustion engine and a tip end thereof (right end in FIG. 1). A rotary shaft for opening and closing a valve comprising an internal rotor 20 integrally mounted on the camshaft 10, an external rotor 30, a front plate 40, and a rear plate 50 which are externally rotatable relative to the camshaft 10 and the internal rotor 20 within a predetermined range.
A rotation transmission member including a timing sprocket 51 integrally provided on the outer periphery of the rear plate 50; five vanes 60 mounted on the inner rotor 20;
, And the like. As is well known, the timing sprocket 51 is configured to transmit rotational power clockwise in FIG. 2 from a crankshaft (not shown) via a crank sprocket and a timing chain.

The camshaft 10 has a well-known cam 11 for opening and closing an intake valve.
An advancing passage 12 and a retarding passage 13 extending in the axial direction are provided. The advance passage 12 is connected to a connection port 91 a of a housing 91 of the switching valve 90 through a radial passage provided in the camshaft 10, an annular groove, and a connection passage 71 provided in the cylinder head 70. Also, the retard passage 13
Is connected to a connection port 91b of the housing 91 of the switching valve 100 via a radial passage and an annular groove provided in the camshaft 10 and a connection passage 72 provided in the cylinder head 70.

The switching valve 90 includes a spring 9 together with a movable core 94 and a spool 92 inserted movably in the axial direction in a housing 91 by energizing a solenoid 95.
1 can be moved to the left in FIG. 1. When the power is turned off, the supply port 91c of the housing 91 connected to an oil pump (not shown) driven by the internal combustion engine is connected to the annular groove 92d of the spool 92. So that the connection port 91a communicates with the discharge port 92c via the communication passage 92a of the spool 92, and the supply port 91c is connected to the connection port 91a via the annular groove 92d when power is supplied. In addition to the communication, the connection port 91b is configured to communicate with the discharge port 92c via the communication passage 92b of the spool 92. Therefore, when the solenoid 95 is not energized, hydraulic oil is supplied to the retard passage 13, and when energized, hydraulic oil is supplied to the advance passage 12. Note that the discharge port 92c is connected to the cylinder head 7
0 and communicates with the inside of the cylinder head 70 through a discharge passage 73.

The inner rotor 20 has a single mounting bolt 81
And is integrally fixed to the camshaft 10 by
Each of the five vanes 60 has a vane groove 21 for mounting the vanes 60 so as to be movable in the radial direction.
0 and when the relative phases of the inner rotor 20 and the outer rotor 30 are synchronized at a predetermined phase (the most retarded position).
A receiving hole 26 into which a predetermined amount of the head 1 is inserted, a passage 27 for supplying and discharging hydraulic oil from the advance passage 12 to the receiving hole 26,
A passage for supplying and discharging hydraulic oil from the advance passage 12 to the advance oil chamber R1 partitioned by each vane 60 (an annular groove communicating with the advance passage 12 and five annular grooves extending radially outward from the annular groove). And a retarding oil chamber R2 defined by each vane 60 (three retarding oil chambers R2 excluding the retarding oil chambers R2 on both sides of the upper retarding oil chamber R2 in FIG. 2). Oil chamber R2)
A passage 25 for supplying and discharging hydraulic oil from the retard passage 13. The receiving hole 26 is formed on the outer periphery of the internal rotor 20 in the radial direction. Each vane 60 is urged radially outward by a vane spring 61 (see FIG. 1) housed in the bottom of the vane groove 21.

The outer rotor 30 is mounted on the outer periphery of the inner rotor 20 so as to be relatively rotatable within a predetermined range. A front plate 40 and a rear plate 50 are joined to both sides thereof, and are integrally formed by three connecting bolts 82. Are linked together. In addition, five protrusions 31 are formed on the inner periphery of the outer rotor 30 at predetermined intervals in the circumferential direction so as to protrude inward in the radial direction.
The outer rotor 30 is rotatably supported by the inner rotor 20 in a configuration in which the outer rotor 30 is in sliding contact with the outer peripheral surface of the outer rotor 30. It is formed in the direction.

In the present embodiment, the advancing direction end face of each projection 31 partitioning the retarding oil chamber R2 adjacent to the upper retarding oil chamber R2 in FIG. Each of the communication ports 31a extends radially outward along the (direction side end surface) and opens the retarding oil chamber R2 to the atmosphere.

Each vane 60 has an arc-shaped cross section at its tip (see FIG. 2), and is mounted between the plates 40 and 50 in the vane groove 21 of the internal rotor 20 so as to be movable in the radial direction. The fluid pressure chamber R0 formed between each protrusion 31 of the outer rotor 30 and the inner rotor 20 is divided into an advance oil chamber R1 and a retard oil chamber R2.
The phase (relative rotation amount) adjusted by the valve opening / closing timing control device is limited by abutting on the rotation direction end face of each projection 31 formed at zero.

The lock pin 101 is slidably mounted in the evacuation hole 32 in the axial direction.
Urged toward the internal rotor 20. The spring 102 is interposed between the lock pin 101 and the retainer 103, and the retainer 103 is fixed in the evacuation hole 32 by a snap ring 104 so as not to come off.

In the valve opening / closing timing control apparatus of the present embodiment configured as described above, the state shown in FIG. 2, that is, the balance state in the intermediate phase (the pushing of the advance oil pressure in each advance oil chamber R1 by the advance oil pressure) is performed. The solenoid 95 of the switching valve 90 is energized in a state where the pressure is balanced with the sum of the pressing force due to the retard hydraulic pressure in each retard oil chamber R2 and the torque applied to the camshaft 10). Hydraulic oil is supplied to each advance oil chamber R1 through the advance passage 12 and the passage 24, and each passage 25 and the retard passage 1 from each retard oil chamber R2.
When the hydraulic oil is discharged through the valve 3 and the switching valve 90, the internal rotor 20 and each vane 60 rotate relative to the external rotor 30, the plates 40, 50, and the like, in the advance angle (clockwise direction in FIG. 2). The relative rotation amount (maximum advance amount) is determined for each vane 6
0 is restricted by contacting one end surface of the protrusion 31. Further, by setting the solenoid 95 of the switching valve 90 to a non-energized state, each of the retard oil chambers R2 (the retard valves on both sides of the upper retard oil chamber R2 in FIG. Hydraulic oil is supplied to the three retard oil chambers R2) except for the oil chamber R2, and each of the advance oil chambers R1 is connected to each of the passages 24.
When the operating oil is discharged through the advance passage 12 and the switching valve 90, the internal rotor 20 and each vane 60
0, relative rotation with respect to both plates 40, 50, etc. in the retard side (counterclockwise direction in FIG. 2), and the relative rotation amount (maximum retard amount) is such that each vane 60 hits the other end surface of the protruding member 31. Limited by contact.

By the way, during normal operation of the internal combustion engine, a fluctuating torque acts on the camshaft 10, and the camshaft 10 always exerts a torque on the retard side. For this reason, as described above, at the time of phase conversion of the advance angle,
As a force that hinders rotation of the internal rotor 20 and the like in the advance direction, the cam is pressed by the retarding oil pressure of the retarding oil chamber R2 (a force for pushing hydraulic oil from the retarding oil chamber R2 to the passage 25). A force obtained by applying a torque generated on the shaft 10 acts on a rotating shaft such as the internal rotor 20. Thus, in the present embodiment, of the five retarding oil chambers R2, two retarding oil chambers R2 (the retarding oil chambers on both sides of the upper retarding oil chamber R2 in FIG. 2). Is not communicated with the retard passage 13 through the passage 25, and is opened to the atmosphere through the communication port 31a. As a result, the force that hinders rotation of the internal rotor 20 and the like in the advance direction during phase conversion of the advance angle is reduced by the absence of the pressing force of the two retard oil chambers R2 due to the retard hydraulic pressure. Therefore, particularly when the viscosity of the hydraulic oil is high due to a low oil temperature, the responsiveness during the phase conversion of the advance angle can be improved. Although the pressing force of the retarding oil chamber R2 due to the retarding hydraulic pressure decreases, the above-described torque always acts in the retarding direction. Absent.

In the above embodiment, two of the five retarding oil chambers are shut off from the retard passage and opened to the atmosphere. However, the retarding oil chamber ( And the number of advance oil chambers) can be increased or decreased.

In the above-described embodiment, the head of the lock pin 70 assembled to the outer rotor 29 has the receiving hole of the inner rotor 20 when the advance oil chamber R1 has the minimum volume (most retarded state). 22, the head of the lock pin assembled to the external rotor is inserted into the receiving hole of the internal rotor in a state where the retarding oil chamber R2 has the minimum volume (the most advanced state). It is also possible to configure and implement such. Also. In the above embodiment, the present invention is applied to the valve opening / closing timing control device mounted on the intake camshaft 10, but the present invention is similarly applied to the valve opening / closing timing control device mounted on the exhaust camshaft. It can be implemented.

[0022]

As described above, according to the present invention, at least one of the retarding chambers is cut off from the second fluid passage and opened to the atmosphere. The force that inhibits the rotation of the rotating shaft is reduced due to the elimination of the pressing force of the retard hydraulic pressure in the retard chamber released to the atmosphere, especially when the viscosity of the hydraulic oil due to low oil temperature is high. , The response at the time of phase conversion of the advance angle can be improved.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view showing an embodiment of a valve timing control apparatus according to the present invention.

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

[Explanation of symbols]

 Reference Signs List 10 camshaft (rotary shaft) 12 advance passage (first fluid passage) 13 retard passage (second fluid passage) 20 internal rotor (rotation shaft) 30 external rotor (rotation transmission member) 31 protrusion 31a communication port 40 front Plate 50 Rear plate 51 Timing sprocket 60 Vane 70 Cylinder head 90 Switching valve R0 Fluid pressure chamber R1 Advance oil chamber (advance chamber) R2 Delay oil chamber (retard chamber)

Claims (1)

[Claims] 1. A rotation shaft for opening and closing a valve rotatably mounted on a cylinder head of an internal combustion engine, and a rotation transmission for transmitting rotation power from a crankshaft, which is rotatably mounted on the rotation shaft in a predetermined range. A member, a plurality of vanes attached to one of the rotating shaft or the rotation transmitting member, and an advancing chamber and a retarding chamber respectively formed between the rotation transmitting shaft and the rotation transmitting member by the vane. A plurality of fluid pressure chambers, a first fluid passage for supplying and discharging fluid to each of the advance chambers, and a second fluid passage for supplying and discharging fluid to each of the retard chambers. A valve opening / closing timing control device used to control the opening / closing timing of an intake valve or an exhaust valve of an internal combustion engine, wherein at least one of the retard chambers is disconnected from the second fluid passage and opened to the atmosphere. A valve timing control device.