JP2010169009A - Valve opening/closing timing control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a valve opening/closing timing control device promptly changing the relative rotational phase of a driven rotating member with respect to a driving rotating member in advancing directions even if a temperature of hydraulic fluid is low. <P>SOLUTION: When the relative rotational phase of an internal rotor 4 with respect to an external rotor 5 is changed in the advancing direction S1, the temperature of the hydraulic fluid is detected. When the temperature of the hydraulic fluid is low, an oil passage changeover valve 24 is changed over to a first position 24A. Similarly, when the temperature of the hydraulic fluid is high, the oil passage changeover valve 24 is changed over to a second position 24B. When the relative rotational phase of the internal rotor 4 with respect to the external rotor 5 is changed over in the advancing direction S2, the oil passage changeover valve 24 is changed over to a third position 24C regardless of the temperature of the hydraulic fluid. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a valve opening / closing timing control device for controlling the opening / closing timing of intake and exhaust valves of an internal combustion engine.

  Patent Document 1 discloses a hydraulic chamber (advanced chamber and retarded chamber) to which at least two or more advanced side chambers and retarded side chambers (corresponding to advanced chambers and retarded chambers) are supplied and hydraulic pressure is supplied. The phase variable mechanism (corresponding to a valve opening / closing timing control device) capable of improving the responsiveness by changing the number of the above is changed according to the operating state of the internal combustion engine.

  Specifically, of the four advance angle side compartments and the retard angle side chambers, the three advance angle side compartments and the three retard angle side compartments are operated by the first electromagnetic switching valve which is a three-position five-port switching valve. Oil supply / discharge is permitted or prohibited, and one of the four advance chambers and one of the retard chambers is a three-position four-port switching valve. The supply and discharge of hydraulic fluid is permitted or prohibited by the electromagnetic switching valve. When the amount of hydraulic oil supplied to the valve opening / closing timing control device is small, supply of hydraulic oil is permitted by the first electromagnetic switching valve, and supply of hydraulic oil is prohibited by the second electromagnetic switching valve. As a result, the number of advance side compartments and retard side compartments for supplying hydraulic oil is reduced, and the responsiveness of the valve timing control device is improved.

  In other words, Patent Document 1 discloses that responsiveness is improved by reducing the number of hydraulic chambers to be used under the same operation state.

  On the other hand, when the amount of hydraulic oil supplied to the valve opening / closing timing control device is large, by permitting the supply of hydraulic oil by the first electromagnetic switching valve and the second electromagnetic switching valve, all the advance side compartments In addition, hydraulic oil is supplied to the retard side compartment and the drive torque is relatively increased to improve the responsiveness of the valve timing control device.

JP 2007-170180 A

  The valve opening / closing timing control device disclosed in Patent Document 1 corresponds to the increase / decrease of the hydraulic chamber to which the hydraulic oil is supplied according to the operating state of all internal combustion engines, including when the hydraulic oil is at a low temperature and at a high temperature. Yes.

  Therefore, two switching valves are provided, and a plurality of hydraulic chambers are divided into two groups so that hydraulic oil can be supplied and discharged. However, since the two switching valves are provided, it is necessary to form an advance oil passage and a retard oil passage, respectively, resulting in disadvantages such as an increase in installation location of the switching valve and an increase in processing cost of each oil passage.

  Generally, in the valve opening / closing timing control device, since the fluctuation torque of the camshaft acts in the retard direction of the relative rotation phase, the retard direction is more easily moved than the advance direction.

  Further, the hydraulic oil used in the valve opening / closing timing control device has a property that the viscosity is high when the oil temperature is low, and the viscosity is low when the oil temperature is high. When the viscosity of the hydraulic oil is high, the flow path resistance is large, and the moving speed at which the hydraulic oil flows through the oil path is slow. When the viscosity of the hydraulic oil is low, the flow path resistance is small, and the moving speed at which the hydraulic oil flows through the oil path increases. However, when the hydraulic oil viscosity is high, the amount of leakage from the gaps between the members constituting the valve opening / closing timing control device is small, so that the hydraulic pressure acting on the hydraulic chamber is high and the hydraulic oil viscosity is low, Since the amount of leakage from the gaps between the members constituting the opening / closing timing control device is large, the hydraulic pressure acting on the hydraulic chamber tends to be low. Therefore, when the hydraulic oil at the time of starting the internal combustion engine is at a low temperature, the hydraulic oil has a high viscosity, and it takes time until the hydraulic oil is supplied to the hydraulic chamber as compared with a case where the hydraulic oil has a low viscosity.

  Therefore, the response speed for changing the relative rotational phase is slower in the advance direction than in the retard direction, and is slower at low temperatures than when the hydraulic oil is at high temperatures.

  The present invention has been made in view of the characteristics of the above valve opening / closing timing control device, and is limited to the advance direction of the internal combustion engine at the low temperature and the relative rotational phase when the hydraulic oil is at a low temperature. It is an object of the present invention to provide a valve timing control device with improved responsiveness with a simple oil passage configuration.

In order to solve the above technical problem, the first technical means taken in the present invention is:
A drive-side rotating member that rotates synchronously with the crankshaft of the internal combustion engine;
A driven-side rotating member that is coaxially disposed with respect to the driving-side rotating member and rotates synchronously with a camshaft for opening and closing the valve of the internal combustion engine;
A plurality of advance angles formed by the drive side rotation member and the driven side rotation member and changing the relative rotation phase of the driven side rotation member with respect to the drive side rotation member in the advance direction by supplying hydraulic oil. A plurality of retarding chambers that change the chamber and the relative rotational phase in the retarding direction;
An advance oil passage for supplying and discharging hydraulic oil to and from the plurality of advance chambers, and a retard oil passage for supplying and discharging hydraulic oil to and from the plurality of retard chambers;
An oil pump capable of supplying hydraulic oil to the advance oil passage and the retard oil passage;
An oil path switching valve that switches between permitting and prohibiting the supply and discharge of hydraulic oil supplied from the oil pump to the advance oil path and the retard oil path;
The advance oil passage is branched into two, a first advance oil passage and a second advance oil passage, by one oil passage switching valve,
The first advance oil passage supplies and discharges hydraulic oil to and from one advance chamber among the plurality of advance chambers,
The second advance oil passage is a valve opening / closing timing control device that supplies / discharges hydraulic oil to / from another advance chamber among the plurality of advance chambers.

The second technical means is the first technical means,
A lock mechanism that restrains relative rotation of the driven side rotation member with respect to the drive side rotation member by a lock body;
The hydraulic oil supplied to and discharged from the first advance oil passage is to press the lock body to release the restriction on the relative rotation of the driven side rotating member with respect to the driving side rotating member.

The third technical means is the first technical means or the second technical means,
The oil passage switching valve at least a first position that permits the supply of hydraulic oil to the first advance oil passage and prohibits the supply of hydraulic oil to the second advance oil passage; And a second position allowing the supply of hydraulic oil to the first advance oil passage and the second advance oil passage.

The fourth technical means is any one of the first technical means to the third technical means.
The oil passage switching valve is switchable between the first advance oil passage and the second advance oil passage based on the detection result of the oil temperature of the hydraulic oil.

  According to the invention of claim 1, the advance oil passage is branched into two of the first advance oil passage and the second advance oil passage by one oil passage switching valve, and the first advance oil passage is formed. Supplies and discharges hydraulic oil to one advance chamber of the plurality of advance chambers, and the second advance oil passage supplies hydraulic oil to the other advance chambers of the plurality of advance chambers. I decided to eliminate it.

  As a result, when the hydraulic oil has a high viscosity and the hydraulic pressure acting on the advance chamber is high, a plurality of advance angles can be obtained by supplying the hydraulic oil to only one advance chamber via the first advance oil passage. Compared to the case of supplying hydraulic oil to the chamber, one advance chamber is filled in a short amount of oil and in a short time. Therefore, since the hydraulic oil (hydraulic pressure) supplied to one advance chamber acts on the driven side rotation member, the relative rotation phase of the driven side rotation member with respect to the drive side rotation member can be quickly changed in the advance direction.

  According to the second aspect of the present invention, the lock oil further includes a lock mechanism that restrains the relative rotation of the driven-side rotation member with respect to the drive-side rotation member by the lock body, and the hydraulic oil supplied to and discharged from the first advance oil passage is a lock The body is pressed to release the restriction on the relative rotation of the driven side rotating member with respect to the driving side rotating member.

  As a result, when the hydraulic oil is supplied to the first advance oil passage, the lock can be reliably released before the hydraulic oil is supplied to one advance chamber or the sub advance chamber, and the driven side rotating member is driven. The relative rotation phase of the side rotation member can be changed in the advance direction.

  According to the invention of claim 3, the oil passage switching valve at least allows the supply of hydraulic oil to the first advance oil passage and prohibits the supply of hydraulic oil to the second advance oil passage. And a second position where the supply of hydraulic oil to the first advance oil passage and the second advance oil passage is permitted.

  Thereby, when the viscosity of the hydraulic oil is high, the hydraulic oil is supplied to only one advance chamber or sub-advance chamber by switching the oil passage switching valve to the first position, and the driven side rotating member Hydraulic pressure acts on the. Therefore, the relative rotation phase of the driven side rotating member with respect to the driving side rotating member can be quickly changed in the advance direction.

  According to the invention of claim 4, the oil passage switching valve is switchable between the first advance oil passage and the second advance oil passage based on the detection result of the oil temperature of the hydraulic oil. did.

  Thereby, since the viscosity of hydraulic fluid can be estimated with the oil temperature of hydraulic fluid, control of an oil path switching valve can be performed easily.

1 is a schematic diagram of a valve opening / closing timing control device according to an embodiment of the present invention. II-II sectional drawing of FIG.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 and 2.

  The valve opening / closing timing control device includes an external rotor 5 as a drive-side rotating member that can rotate around the axis of a camshaft 9 that opens and closes an engine valve in synchronization with the crankshaft 110 of the engine, and an internal portion of the external rotor 5. And an internal rotor 4 as a driven side rotating member that rotates integrally with the camshaft 9 so as to be capable of changing the phase with the external rotor 5.

  The external rotor 5 is narrowly divided into a front plate 5A attached to the side opposite to the side to which the camshaft 9 is connected, a rear plate 5B attached to the side to which the camshaft 9 is connected, and the front plate 5A and the rear plate 5B. It is comprised with the housing 5C held.

  A gear 5D is formed on the outer periphery of the housing 5C. A power transmission member 120 such as a timing chain or a timing belt is installed between the gear 5D and a gear (not shown) attached to the crankshaft of the engine.

  On the inner periphery of the housing 5C, a plurality of projecting portions 5E projecting radially inward are provided apart from each other along the rotational direction. Further, on the inner periphery of the housing 5C, there are formed a retreat groove 6B for housing the lock body 6A, and a housing hole 6D for the spring 6C that communicates with the retreat groove 6B and biases the lock body 6A in the radially inward direction. Yes.

  The internal rotor 4 is integrally assembled at the tip of the camshaft 9 that constitutes the rotation shaft of the cam that controls the opening / closing timing of the intake valve or exhaust valve of the engine, and is within a predetermined relative rotation range with respect to the external rotor 5. The interior is relatively rotatable. Further, the inner rotor 4 is formed with a lock groove 6E that is accommodated when the lock body 6A moves in the radially inward direction.

  The lock mechanism 6 includes the lock body 6A, the retracting groove 6B, the spring 6C, the receiving hole 6D, and the locking groove 6E described above. Further, the urging force of the spring 6C is such that it can overcome the centrifugal force caused by the rotation of the internal rotor 4 and the external rotor 5 and can be unlocked even if the hydraulic pressure acting on the lock body 6A is low due to the hot hydraulic oil.

  In the outer rotor 5 and the inner rotor 4, the hydraulic chamber 1 is formed between the adjacent protrusions 5 </ b> E of the outer rotor 5. In the first embodiment, an example having four hydraulic chambers 1 is illustrated.

  The hydraulic chamber 1 is divided into an advance chamber 2 and a retard chamber 3 by a vane 7.

  The relative rotatable range of the inner rotor 4 with respect to the outer rotor 5 corresponds to a range in which the vane 7 can move inside the hydraulic chamber 1, that is, a range between the most retarded angle phase and the most advanced angle phase.

  The torsion spring 8 is attached with one end locked to the front plate 5 </ b> A and the other end locked to the internal rotor 5, and biases the internal rotor 5 toward the advance direction S <b> 1 with respect to the external rotor 4. . In the present embodiment, the torsion spring 8 is locked to the front plate 5A, but may be locked to the rear plate 5B.

  Next, the oil passage will be described.

  The oil passage according to the first embodiment includes first advance oil passages 10 and 20 and a second advance oil passage 11 that change the relative rotation phase of the inner rotor 4 with respect to the outer rotor 5 in the advance angle direction S1. , 21 and retarding oil passages 12, 22 for changing the relative rotational phase of the inner rotor 4 with respect to the outer rotor 5 in the retarding direction S2.

  The hydraulic oil discharged from the oil pump 23 and supplied to the supply oil passage 27 is transferred to the first advance oil passage 20, the second advance oil passage 21, and the retard oil passage 22 by the oil passage switching valve 24. Is permitted or prohibited. A discharge oil passage 28 communicating with the oil pan 26 discharges hydraulic oil discharged from the first advance oil passage 20, the second advance oil passage 21, and the retard oil passage 22 to the oil pan 26. .

  The first advance oil passages 10 and 20 are oil passages that supply and discharge hydraulic oil to and from one advance chamber 2A adjacent to the lock mechanism 6 in the four advance chambers 2. The second advance oil passages 11 and 21 are oil passages that supply and discharge hydraulic oil to and from the other three advance chambers 2B, 2C, and 2D that the first advance oil passage 20 does not supply and discharge. The retard oil passages 12 and 22 are oil passages for supplying and discharging hydraulic oil to and from the four retard chambers 3.

  The oil passage switching valve 24 permits supply of hydraulic oil to the first advance oil passages 10 and 20, prohibits supply of hydraulic oil to the second advance oil passages 11 and 21, and retards oil. Permits the supply of hydraulic oil to the first position 24A that permits the discharge of hydraulic oil from the passages 12 and 22, the first advance oil passages 10 and 20, and the second advance oil passages 11 and 21. The second position 24B permitting the discharge of the hydraulic oil from the retard oil passages 12, 22 and the first advance oil passages 10, 20 and the second advance oil passages 11, 21 A third position 24C that permits discharge and permits the supply of hydraulic oil to the retarded oil passages 12 and 22; The oil passage switching valve 24 is a so-called 3-position 6-port switching valve. Further, the oil passage switching valve 24 operates so that the first position 24A, the second position 24B, and the third position 24C can be switched by a control signal from the ECU 25 that is a control means.

  The ECU 25 controls the oil passage switching valve 24 based on the detection result of the oil temperature of the hydraulic oil. Specifically, when the relative rotation phase of the inner rotor 4 with respect to the outer rotor 5 is changed to the advance angle direction S1, the oil temperature of the hydraulic oil is detected, and the oil path is switched when the oil temperature is low. The valve 24 is switched to the first position 24A. Similarly, when the oil temperature is high, the oil passage switching valve 24 is switched to the second position 24B. When the relative rotation phase of the inner rotor 4 with respect to the outer rotor 5 is changed in the retarding direction S2, the oil passage switching valve 24 is switched to the third position 24C regardless of the oil temperature of the hydraulic oil.

  Next, the operation of the valve timing control device will be described.

  When the engine is stopped, the oil pump 23 is stopped, and hydraulic oil (hydraulic pressure) is not supplied to the hydraulic chamber 1. At this time, the lock body 6A is immersed in the lock groove 6E of the inner rotor 4, and the relative rotation between the outer rotor 5 and the inner rotor 4 is restricted.

  When the engine starts, the oil pump 23 is driven and hydraulic oil is discharged from the oil pump 23. When changing the phase in the advance direction S1, the ECU 25 switches the oil passage switching valve 24 to the first position 24A based on the detection result of the oil temperature of the hydraulic oil. Then, since the hydraulic oil supplied to the internal rotor 4 is supplied only from the first advance oil passage 10, the hydraulic oil presses the lock body 6A against the urging force of the spring 6C in the radially outward direction. To unlock. Further, since the hydraulic oil is supplied to only one advance chamber 2A through the first advance oil passage 10, the hydraulic oil is supplied to the four advance chambers 2A, 2B, 2C, and 2D. Thus, since the advance chamber 2A is filled in a small amount of oil and in a short time and the hydraulic oil (hydraulic pressure) supplied to the advance chamber 2A acts on the internal rotor 4, the relative rotation of the internal rotor 4 with respect to the external rotor 5 The phase can be quickly changed to the advance direction S1.

  When a certain time elapses after the engine is started, the hydraulic oil temperature rises. When the hydraulic oil temperature rises, the amount of leakage from the gaps between the members increases, and the hydraulic pressure acting on one advance chamber 2A decreases. The relative rotation phase of the internal rotor 4 cannot be changed in the advance direction S1.

  At this time, the ECU 25 switches the oil passage switching valve 24 to the second position 24B based on the detection result of the oil temperature of the hydraulic oil. Then, the hydraulic oil supplied to the internal rotor 4 is supplied from the first advance oil passage 10 and the second advance oil passage 11. Relative rotation of the internal rotor 4 with respect to the external rotor 5 in order to increase the pressure receiving area by supplying hydraulic oil to the four advance chambers 2A, 2B, 2C, and 2D even when the hydraulic pressure acting on one advance chamber 2A is low The phase can be changed to the advance direction S1.

  When the relative rotation phase of the inner rotor 4 with respect to the outer rotor 5 is changed in the retarding direction S2, the oil passage switching valve 24 is switched to the third position 24C regardless of the oil temperature of the hydraulic oil.

DESCRIPTION OF SYMBOLS 1 ... Hydraulic chamber 2, 2A, 2B, 2C, 2D ... Advance angle chamber 3 ... Delay angle chamber 4 ... Internal rotor (driven side rotation member)
5 ... External rotor (drive side rotating member)
6 ... Lock mechanism 6A ... Lock body 7 ... Vane 10 ... First advance oil passage (advance oil passage)
11: Second advance oil passage (advance oil passage)
12 ... retard oil passage 23 ... oil pump 24 ... oil passage switching valve 24A ... first position 24B ... second position 24C ... third position 27 ... Supply oil passage 28 ... Discharge oil passage

Claims (4)

A drive-side rotating member that rotates synchronously with the crankshaft of the internal combustion engine;
A driven-side rotating member that is coaxially disposed with respect to the driving-side rotating member and rotates synchronously with a camshaft for opening and closing the valve of the internal combustion engine;
A plurality of advance angles formed by the drive side rotation member and the driven side rotation member and changing the relative rotation phase of the driven side rotation member with respect to the drive side rotation member in the advance direction by supplying hydraulic oil. A plurality of retarding chambers that change the chamber and the relative rotational phase in the retarding direction;
An advance oil passage for supplying and discharging hydraulic oil to and from the plurality of advance chambers, and a retard oil passage for supplying and discharging hydraulic oil to and from the plurality of retard chambers;
An oil pump capable of supplying hydraulic oil to the advance oil passage and the retard oil passage;
An oil path switching valve that switches between permitting and prohibiting the supply and discharge of hydraulic oil supplied from the oil pump to the advance oil path and the retard oil path;
The advance oil passage is branched into two, a first advance oil passage and a second advance oil passage, by one oil passage switching valve,
The first advance oil passage supplies and discharges hydraulic oil to and from one advance chamber among the plurality of advance chambers,
The valve timing control apparatus according to claim 2, wherein the second advance oil passage supplies and discharges hydraulic oil to and from another advance chamber of the plurality of advance chambers. In claim 1,
A lock mechanism that restrains relative rotation of the driven side rotation member with respect to the drive side rotation member by a lock body;
The hydraulic fluid supplied to and discharged from the first advance oil passage presses the lock body to release the restriction on the relative rotation of the driven side rotating member with respect to the driving side rotating member. Timing control device. In claim 1 or claim 2,
The oil passage switching valve at least a first position that permits the supply of hydraulic oil to the first advance oil passage and prohibits the supply of hydraulic oil to the second advance oil passage; A valve opening / closing timing control device comprising: a first advance oil passage and a second position permitting supply of hydraulic oil to the second advance oil passage. In any one of Claims 1 thru | or 3,
The oil path switching valve is switchable between the first advance oil path and the second advance oil path based on a detection result of the oil temperature of the hydraulic oil. Timing control device.

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