JP2007170180A - Variable valve gear of internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase the response rate of a variable valve gear by making variable the number of hydraulic chambers into which hydraulic pressure is supplied according to the operating conditions of an internal combustion engine. <P>SOLUTION: This variable valve gear 20 of an internal combustion engine comprises a housing 1 rotatingly driven by a crankshaft and a rotor 2 combined with the housing 1 rotatably relative to each other and driving the camshaft. A hydraulic chamber 7 is formed between the housing 1 and the rotor 2. The inside of the hydraulic chamber 7 is divided into an advance-angle side divided chamber 12 and a retard-angle side divided chamber 13 by a vane 3. The relative phase of the housing 1 to the rotor 2 is variably controlled by the pressure difference between the advance-angle side divided chamber 12 and the retard-angle side divided chamber 13 produced by the hydraulic pressure supplied into the hydraulic chamber 7. The variable valve gear comprises at least two or more hydraulic chambers 7, and the number of the hydraulic chambers 7 into which the hydraulic pressure is supplied is changed according to the operating state of the internal combustion engine. Consequently, the response rate of the variable valve gear 20 can be enhanced. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a variable valve operating apparatus for an internal combustion engine.

  Patent Document 1 discloses a configuration in which hydraulic oil can be supplied from a plurality of independently driven pumps to a hydraulic pressure supply section of a variable valve mechanism of an internal combustion engine, so that even at low rotation and low hydraulic pressure. In addition, a hydraulic pressure adjusting device that can compensate for the operation (response speed) of the variable valve mechanism is disclosed.

Japanese Patent Application Laid-Open No. 2004-228561 is intended to improve the response when the valve opening / closing timing is changed to the advance side in the valve opening / closing timing control device used for controlling the opening / closing timing of the intake valve or the exhaust valve. In addition, a technique is disclosed in which at least one of the retarding chambers is opened to the atmosphere to reduce the counter-torque during advance and improve the response during advance. The valve opening / closing timing control device disclosed in Patent Document 1 includes a rotary shaft for valve opening / closing, a rotation transmission member that is externally mounted on the rotary shaft so as to be relatively rotatable within a predetermined range, and that transmits rotational power from a crankshaft, and a rotary shaft Or a plurality of vanes attached to one of the rotation transmission members, and a plurality of fluid pressure chambers formed between the rotation shaft and the rotation transmission member and divided into an advance chamber and a retard chamber by the vanes, respectively. The first fluid passage for supplying and discharging the hydraulic oil to and from each advance angle chamber, and the second fluid passage for supplying and discharging the hydraulic oil to and from each retard angle chamber.
JP 2004-263609 A JP 11-159308 A

  However, in Patent Document 1, since a plurality of oil pumps are necessary, there is a possibility that problems such as an increase in cost and an increase in size due to an increase in the number of parts may occur.

  Further, in Patent Document 2, since the supply of oil to the advance chamber is not cut off, there is a possibility that the response when the amount of oil supplied to the valve timing control device is small cannot be improved.

  Therefore, the present invention includes a first rotating body that is rotationally driven by a crankshaft of an internal combustion engine, and a second rotating body that is combined with the first rotating body so as to be relatively rotatable and that drives a camshaft. A hydraulic chamber is formed between the first rotating body and the second rotating body, and the hydraulic chamber is divided into the advance side chamber and the retard side chamber by the vane, and the advance caused by the hydraulic pressure supplied to the hydraulic chamber is divided. In a variable valve operating apparatus for an internal combustion engine in which the relative phase between the first rotating body and the second rotating body is variably controlled by the pressure difference between the angular side chamber and the retarded side chamber, there are at least two hydraulic chambers. In addition, the number of hydraulic chambers to which hydraulic pressure is supplied is changed according to the operating state of the internal combustion engine. That is, the number of hydraulic chambers for supplying hydraulic pressure varies depending on the amount of oil that can be supplied to the variable valve operating apparatus.

  According to the present invention, since the number of hydraulic chambers for supplying hydraulic pressure is variable according to the operating state of the internal combustion engine, that is, according to the amount of oil that can be supplied to the variable valve operating device, the cost can be reduced with a simple configuration. While suppressing, the response speed of the variable valve operating apparatus can be improved.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a schematic configuration of the variable valve operating apparatus 20.

  The variable valve operating apparatus 20 includes a lift operating angle variable mechanism 21 that can change the lift / operating angle of the valve, and a phase variable mechanism 41 that continuously delays the phase of the lift center angle of the valve.

  The variable lift operating angle mechanism 21 includes a drive shaft 22 driven by a crankshaft of an internal combustion engine, an eccentric cam 23 fixed to the drive shaft 22, a control shaft 32 supported rotatably, and the control shaft. The rocker arm 26 is swingably supported by the eccentric cam portion 38 of the 32 and the swing cam 29 that presses the valve stem 30 via the lash adjuster 1. The eccentric cam 23 and the rocker arm 26 are linked. The rocker arm 26 and the swing cam 29 are linked by a link member 28.

  The rocker arm 26 is supported by an eccentric cam portion 38 so as to be able to swing at the substantially central portion, and the arm portion of the link arm 24 is linked to one end portion thereof via the connecting pin 25 and the other end portion. The upper end portion of the link member 28 is linked via the connecting pin 27. The eccentric cam portion 38 is eccentric from the axis of the control shaft 32, and accordingly, the rocking center of the rocker arm 26 changes according to the angular position of the control shaft 32.

  The swing cam 29 is rotatably supported by being fitted to the outer periphery of the drive shaft 22, and the lower end portion of the link member 28 is linked to the end portion extending laterally via the connecting pin 37. . On the lower surface of the swing cam 29, there is formed a cam surface in which a base circle portion concentric with the drive shaft 22 and a lift portion extending in a predetermined curve from the base circle surface are formed. The base circle part and the lift part come into contact with the lash adjuster 1 in accordance with the swing position of the swing cam 29.

  The control shaft 32 is configured to rotate within a predetermined angle range by a lift operation angle control actuator 33 provided at one end. The lift operating angle control actuator 33 is composed of, for example, an electric motor that drives the control shaft 32 via a worm gear 35, and is controlled by a control signal from an engine control unit (ECU) 39. The rotation angle of the control shaft 32 is detected by the control shaft sensor 34.

  According to the lift operating angle variable mechanism 21, the lift and operating angle of the valve (for example, the intake valve) are continuously expanded and reduced simultaneously according to the rotational angle position of the control shaft 32. As the magnitude of the valve changes, the valve opening timing and the valve closing timing change substantially symmetrically.

  On the other hand, the phase variable mechanism 41 is controlled based on a command from the ECU 39, and uses a hydraulic pressure to connect the drive shaft 22 and the sprocket 42 provided at the front end of the drive shaft 22 to a predetermined angle. The valve is relatively rotated within the range, and the lift center angle in the valve lift is delayed. That is, the lift characteristic curve itself does not change, and the whole advances or retards. This change can also be obtained continuously. The control state of the phase variable mechanism 41 is detected by a drive shaft sensor 36 that responds to the rotational position of the drive shaft 22. The sprocket 42 is interlocked with the crankshaft via a timing chain or timing belt (not shown), and is integrally provided on the outer periphery of the housing 1 described later.

  Therefore, by combining the two variable controls, the valve opening timing and closing timing can be variably controlled together with the lift amount. For example, when applied to the intake valve side, it flows into the cylinder without depending on the throttle valve (not shown). The intake air amount to be controlled can be controlled according to the load.

  FIG. 2 is an explanatory view schematically showing a specific configuration of the phase variable mechanism 41 that is a main part of the present invention and an oil passage configuration thereof.

  The phase variable mechanism 41 is assembled to the housing 1 as the first rotating body, the rotor 2 as the second rotating body housed in the housing 1, the four vanes 3 assembled to the rotor 2, and the housing 1. The lock key 4 is roughly constituted.

  The sprocket 42 described above is fixed to the front end surface of the housing 1. The rotor 2 is rotatable relative to the housing 1 by a predetermined angle, and is fixed to the front end of the drive shaft 22 by a bolt (not shown). That is, the housing 1 rotates in synchronization with the crankshaft, the rotor 2 rotates with the rotation of the housing 1 to drive the drive shaft 22, and the relative rotation between the housing 1 and the rotor 2 causes the drive shaft to rotate. The phase with respect to 22 crankshafts is delayed. The housing 1 and the rotor 2 are arranged coaxially with respect to the rotation center of the drive shaft 22.

  The four vanes 3 are attached to the outer periphery of the rotor 2 at substantially constant angular intervals, and extend in the radial direction of the drive shaft 22.

  Four substantially fan-shaped recesses 5 in which the four vanes 3 are accommodated are formed inside the housing 1, and a relatively protruding partition wall 6 is formed between adjacent recesses 5. ing. That is, four hydraulic chambers 7 are formed between the housing 1 and the rotor 2 by the respective recesses 5.

  One of the partition walls 6 accommodates a housing groove 8 that houses the lock key 4 and a spring 9 that continues to the housing groove 8 and biases the lock key 4 inward in the crankshaft radial direction. A spring accommodating groove 10 is formed.

  A lock key engagement groove 11 is formed on the outer peripheral surface of the rotor 2. The lock key engaging groove 11 accommodates the head of the lock key 4 when the state shown in FIG. 2, that is, when the relative position of the rotor 2 and the housing 1 is synchronized at a predetermined relative phase (most retarded angle position). . Hydraulic oil is supplied to the lock key engagement groove 11 from a first advance oil passage 15a described later.

  Each vane 3 meshes with the corresponding recess 5, and the rotor 2 and the housing 1 can rotate relative to each other within a predetermined angle range by meshing the vane 3 with the recess 5. Each hydraulic chamber 7 formed by each recess 5 is divided into an advance side compartment 12 and a retard side compartment 13 by the corresponding vanes 3. In other words, in each hydraulic chamber 7, an advance side chamber 12 is partitioned on one side and a retard side chamber 13 is partitioned on the other side with the vane 3 interposed therebetween.

  When hydraulic oil is supplied to the advance side hydraulic chamber 12, the rotor 2 relatively rotates in the direction in which the valve timing is advanced, and when hydraulic oil is supplied to the retard side hydraulic chamber 13, the valve timing is retarded. The rotor 2 rotates relative to the direction of rotation. In other words, the relative phase between the rotor 2 and the housing 1 is variably controlled by the pressure difference between the advance side chamber 12 and the retard side chamber 13 generated by the hydraulic pressure supplied to the hydraulic chamber 7.

  In the present embodiment, four hydraulic chambers 7 are formed between the rotor 2 and the housing 1, and the first hydraulic chamber 7 a, the third hydraulic chamber 7 c, and the fourth hydraulic chamber among these four hydraulic chambers 7 are formed. The hydraulic oil 7d is supplied and discharged through the first electromagnetic switching valve 14a, and the hydraulic oil is supplied and discharged from the second hydraulic chamber 7b through the second electromagnetic switching valve 14b. The first electromagnetic switching valve 14a is a so-called three-position five-port switching valve, and the second electromagnetic switching valve 14b is a so-called three-position four-port switching valve. Switching of the valve bodies of the first electromagnetic switching valve 14a and the second electromagnetic switching valve 14b is performed by the ECU 39.

  A first advance oil passage 15a is connected to the first advance side compartment 12a of the first hydraulic chamber 7a, and a first retard oil passage 16a is connected to the first retard side compartment 13a. A second advance oil passage 15b is connected to the second advance side chamber 12b of the second hydraulic chamber 7b, and a second retard oil passage 16b is connected to the second retard side compartment 13b. A third advance oil passage 15c is connected to the third advance side chamber 12c of the third hydraulic chamber 7c, and a third retard oil passage 16c is connected to the third retard side compartment 13c. A fourth advance oil passage 15d is connected to the fourth advance side chamber 12d of the fourth hydraulic chamber 7d, and a fourth retard oil passage 16d is connected to the fourth retard side compartment 13d.

  The first electromagnetic switching valve 14a causes the first, third, and fourth advance side compartments 12a, 12c from the oil pump 17 through the first, third, and fourth advance oil passages 15a, 15c, 15d. , 12d are supplied with hydraulic oil, the phase variable mechanism 41 is driven to the advance side. At this time, the hydraulic oil in the first, third, and fourth retard side compartments 13a, 13c, 13d is drained from the first, third, and fourth retard oil passages 16a, 16c, 16d, respectively.

  Further, the first electromagnetic switching valve 14a is switched, and the first, third, and fourth retarded side compartments 13a from the oil pump 17 through the first, third, and fourth retarded oil passages 16a, 16c, 16d. , 13c, 13d, the phase variable mechanism 41 is driven to the retarded angle side. At this time, hydraulic fluid is drained from the first, third, and fourth advance side chambers 12a, 12c, 12d via the first, third, and fourth advance oil passages 15a, 15c, 15d, respectively. .

  The first electromagnetic switching valve 14a has the first, third and fourth advance oil passages 15a, 15c, 15d and the first, third and fourth retard oil passages 16a, when the valve body is in the neutral position. 16c and 16d are closed, and the pressures of the first, third and fourth advance side compartments 12a, 12c and 12d and the first, third and fourth retard side compartments 13a, 13c and 13d are maintained. The

  Hydraulic pressure is supplied to and discharged from the second hydraulic chamber 7b via the second electromagnetic switching valve 14b, and the hydraulic pressure is supplied independently of the first, third and fourth hydraulic chambers 7a, 7c and 7d. Supply is possible.

  When hydraulic fluid is supplied from the oil pump 17 to the second advance angle side chamber 12b by the second electromagnetic switching valve 14b via the second advance angle oil passage 15b, the second retarded angle side chamber 13b The hydraulic oil is drained through the 2 retard oil passage 16b. When the second electromagnetic switching valve 14b is operated to supply hydraulic oil to the second advance side compartment 12b in this way, the first, third and fourth advance angles are caused by the first electromagnetic switching valve 14a. Hydraulic fluid is supplied to the side compartments 12a, 12c, 12d.

  When the second electromagnetic switching valve 14b is switched and hydraulic fluid is supplied from the oil pump 17 to the second retardation side chamber 13b via the second retardation oil passage 16b, the second advance side The hydraulic oil is drained from the compartment 12b through the second advance oil passage 15b. When the second electromagnetic switching valve 14b is operated so as to supply the hydraulic oil to the second retardation side chamber 13b in this way, the first, third and fourth retardations are caused by the first electromagnetic switching valve 14a. Hydraulic fluid is supplied to the side compartments 13a, 13c, 13d.

  The second electromagnetic switching valve 14b can be drained from both the second advance side compartment 12b and the second retard side compartment 13b when the valve body is in the neutral position.

  FIG. 3 shows a control example of the second electromagnetic switching valve 14b. In step (hereinafter simply referred to as “S”) 11, a drive instruction to change the phase of the lift center angle to the phase change mechanism 41 in either the advance side or the retard side with respect to the current phase ( If there is a control command), the process proceeds to S12, and if there is no such drive instruction, the process proceeds to S15. When there is an instruction to drive the phase variable mechanism 41, the first electromagnetic switching valve 14a described above is switched from the neutral position to either the advance side or the retard side.

  In S12, the engine speed and the oil temperature are detected.

  In S13, the amount of oil supplied to the phase variable mechanism 41 is calculated from the engine rotation and the oil temperature, and if this oil amount is equal to or greater than a preset reference oil amount value, the process proceeds to S14. Proceed to S15. The reference oil amount value may be determined based on the amount of oil discharged from the oil pump 17, the amount of oil circulating inside the engine, the amount of oil necessary for filling the hydraulic chamber 7 of the phase variable mechanism 41, and the like. In the end, it is desirable to determine by experimental fit.

  In S14, since the amount of oil supplied to the phase variable mechanism 41 is large, the second electromagnetic switching valve 14b is operated.

  When the second electromagnetic switching valve 14b is operated, the control direction of the second electromagnetic switching valve 14b is the same as the control direction of the first electromagnetic switching valve 14a. That is, when hydraulic fluid is supplied to the advance side compartment 12 of the hydraulic chamber 7 by the first electromagnetic switch valve 14a, the second electromagnetic switch valve 14b is also the second advance side compartment of the second hydraulic chamber 7b. It operates so that hydraulic oil is supplied to 12b. Similarly, when hydraulic fluid is supplied to the retarded side compartment 13 of the hydraulic chamber 7 by the first electromagnetic switching valve 14a, the second electromagnetic switching valve 14b is also connected to the second retarded side of the second hydraulic chamber 7b. It operates so that hydraulic oil is supplied to the compartment 13b.

  On the other hand, in S15, the second electromagnetic switching valve 14b is not operated because there is no instruction to drive the phase variable mechanism 41 or the amount of oil supplied to the phase variable mechanism 41 is small. That is, the valve body of the second electromagnetic switching valve 14b is in a neutral position, and as a result, the second advance side compartment 12b and the second retard side compartment 13b in the second hydraulic chamber 7b are in a drain open state. Yes.

  As described above, in this embodiment, the hydraulic pressure for driving the phase variable mechanism 41 is supplied from one oil pump 17, but the first, third, and fourth hydraulic pressures are provided by having the two electromagnetic switching valves 14a, 14b. The supply of hydraulic pressure to the chambers 7a, 7c, and 7d and the supply of hydraulic pressure to the second hydraulic chamber 7b can be performed independently. That is, the phase variable mechanism 41 can variably set the hydraulic chamber 7 used when changing the phase of the valve lift center angle in three or four two stages. In other words, the phase variable mechanism 41 can change the number of hydraulic chambers 7 to which the hydraulic pressure is supplied according to the operating conditions.

  Therefore, when the amount of oil supplied to the phase variable mechanism 41 is small, the second electromagnetic switching valve 14b is stopped, and the supply of hydraulic pressure to the second hydraulic chamber 7b is stopped, whereby the first, third, and second 4 It is possible to improve the responsiveness (response speed) of the phase variable mechanism 41 by securing the amount of hydraulic oil supplied to the hydraulic chambers 7a, 7c, 7d and preventing a transient shortage of oil. it can.

  FIG. 4 shows the response speed when there are four hydraulic chambers 7 to which hydraulic pressure is supplied under an operating condition where the valve lift amount of the variable lift operating angle mechanism 21 is medium and the engine speed is medium. It is explanatory drawing which compared typically the response speed at the time of three. The response speed here is obtained by dividing the advanced or retarded phase by the time required for the advanced or retarded angle. As is clear from FIG. 4, the response speed is improved by reducing the number of hydraulic chambers 7 to be used under the same operating condition.

  Further, when the amount of oil supplied to the phase variable mechanism 41 is large, the hydraulic pressure that drives the phase variable mechanism 11 by driving the second electromagnetic switching valve 14b and supplying hydraulic pressure to the second hydraulic chamber 7b. Responsiveness (response speed) can be improved by relatively increasing the number of chambers 7 and relatively increasing the driving torque of the phase variable mechanism 41.

  In the present embodiment, three hydraulic chambers 7a, 7c, 7d are assigned to the first electromagnetic switching valve 14a, and one hydraulic chamber 7b is assigned to the second electromagnetic switching valve 14b. The number of hydraulic chambers 7 assigned to the switching valves 14a and 14b is not limited to this. For example, two hydraulic chambers 7 are assigned to the first electromagnetic switching valve 14a and two hydraulic chambers are assigned to the second electromagnetic switching valve 14b. 7 may be assigned. Further, the number of the hydraulic chambers 7 is not limited to four in all, and may be at least two. Similarly, the number of electromagnetic switching valves 14 is not limited to two, and may be at least two.

  In the above-described embodiment, the amount of oil supplied to the phase variable mechanism 41 from the operating state is calculated, and the amount of oil is compared with a preset reference oil amount value. It is determined whether or not to supply hydraulic pressure, that is, whether the number of hydraulic chambers 7 that supply hydraulic pressure is three or four, as shown in FIG. The number of hydraulic chambers to which hydraulic pressure is uniquely supplied may be determined from the size.

  More specifically, when the valve lift amount of the lift operating angle variable mechanism 21 is small, the counter-torque to the phase variable mechanism 41 is small, so that the torque required to drive the phase variable mechanism 41 can be small, and hydraulic pressure is supplied. The number of the hydraulic chambers 7 is set to three to prevent a transient shortage of the oil amount and improve the responsiveness (response speed). When the valve lift amount of the variable lift operation angle mechanism 21 is medium to large and the engine speed is low, the counter torque from the swing cam 29 increases and the discharge pressure of the hydraulic oil from the oil pump 17 is also low. Become. Therefore, responsiveness (response speed) is improved by using all (four) hydraulic chambers 7 and ensuring a sufficient driving torque.

  As a method of changing the number of hydraulic chambers 7 for supplying hydraulic pressure according to operating conditions, as shown in FIG. 6, when the hydraulic pressure supplied to the phase variable mechanism 41 is large, the number of hydraulic chambers 7 to be used. May be reduced to prevent a transient oil shortage and improve the response speed.

  In the above-described embodiment, if the lift operation angle control actuator 33 of the lift operation angle variable mechanism 21 is hydraulically driven, the amount of oil distributed to the phase variable mechanism 41 is relatively reduced. Although the shortage of oil amount may become serious, if the number of the hydraulic chambers 7 of the phase variable mechanism 41 to which the hydraulic pressure is supplied is varied according to the operating state, the response speed due to the shortage of oil amount to the phase variable mechanism 41. Can be effectively prevented.

  The technical idea of the present invention that can be grasped from the above embodiment will be listed together with the effects thereof.

  (1) A first rotating body that is rotationally driven by a crankshaft of an internal combustion engine, and a second rotating body that is combined with the first rotating body so as to be relatively rotatable and that drives a camshaft. A concave portion is provided in one of the second rotating bodies, and a vane is provided in the other. A hydraulic chamber is formed between the first rotating body and the second rotating body by the concave portion, and the hydraulic chamber is advanced by the vane. Relative to the first rotating body and the second rotating body due to the pressure difference between the advance side compartment and the retard side compartment generated by the hydraulic pressure supplied to the hydraulic chamber, divided into the angle side compartment and the retard side compartment. In a variable valve operating apparatus for an internal combustion engine, the phase of which is variably controlled, a hydraulic chamber having at least two hydraulic chambers that are divided into an advance side chamber and a retard side chamber by a vane and to which hydraulic pressure is supplied Depends on the operating condition of the internal combustion engine. To change Te. As a result, the number of hydraulic chambers for supplying hydraulic pressure can be changed according to the operating state of the internal combustion engine, that is, according to the amount of oil that can be supplied to the variable valve gear, so that the cost can be reduced with a simple configuration. The response speed of the variable valve gear can be improved.

  (2) Specifically, the variable valve operating apparatus for an internal combustion engine described in (1) relatively increases the number of hydraulic chambers to which hydraulic pressure is supplied when the hydraulic pressure of the internal combustion engine is low.

  (3) Specifically, the variable valve operating apparatus for an internal combustion engine according to the above (1) relatively reduces the number of hydraulic chambers to which hydraulic pressure is supplied when the amount of supplied oil is small.

  (4) Specifically, the variable valve operating apparatus for an internal combustion engine according to (1) relatively increases the number of hydraulic chambers to which hydraulic pressure is supplied when the engine speed is low.

  (5) Specifically, the variable valve operating apparatus for an internal combustion engine according to (1) described above is configured such that the lift operating angle of the intake valve is continuously expanded / reduced in accordance with the engine operating state. A variable lift operating angle mechanism capable of controlling the intake air amount is provided, and when the lift amount of the intake valve is large, the number of hydraulic chambers to which hydraulic pressure is supplied is relatively increased.

  (6) The variable valve operating apparatus for an internal combustion engine according to any one of the above (1) to (5), specifically, hydraulic pressure is supplied from a single hydraulic source to a plurality of hydraulic chambers.

Explanatory drawing which shows schematic structure of a variable valve apparatus. Explanatory drawing which showed typically the specific structure of the phase variable mechanism which is the principal part of this invention, and its oil-path structure. The flowchart which shows the flow of control of a 2nd electromagnetic switching valve. Explanatory drawing which showed typically the correlation of the number of the hydraulic chambers to which the hydraulic pressure was supplied, and the response speed. The map figure which shows the other calculation method of the number of the hydraulic chambers to which hydraulic pressure is supplied. The map figure which shows the other calculation method of the number of the hydraulic chambers to which hydraulic pressure is supplied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Housing 2 ... Rotor 3 ... Vane 7 ... Hydraulic chamber 12 ... Advance angle side chamber 13 ... Delay angle side chamber 14 ... Electromagnetic switching valve 15 ... Advance angle oil path 16 ... Delay angle oil path 41 ... Phase variable mechanism

Claims (6)

A first rotating body that is rotationally driven by a crankshaft of an internal combustion engine, and a second rotating body that is combined with the first rotating body so as to be relatively rotatable and that drives a camshaft. A recess is provided in one of the bodies, and a vane is provided in the other. A hydraulic chamber is formed between the first rotating body and the second rotating body by the recess, and the hydraulic chamber is advanced by the vane. The phase difference between the first rotating body and the second rotating body is variable depending on the pressure difference between the advance side chamber and the retard side chamber generated by the hydraulic pressure supplied to the hydraulic chamber. In a variable valve system for an internal combustion engine to be controlled,
There are at least two hydraulic chambers whose interior is divided into an advance side chamber and a retard side chamber by a vane, and the number of hydraulic chambers to which hydraulic pressure is supplied is changed according to the operating state of the internal combustion engine A variable valve operating apparatus for an internal combustion engine characterized by   2. The variable valve operating system for an internal combustion engine according to claim 1, wherein when the hydraulic pressure of the internal combustion engine is low, the number of hydraulic chambers to which the hydraulic pressure is supplied is relatively increased.   2. The variable valve operating apparatus for an internal combustion engine according to claim 1, wherein when the amount of oil supplied is small, the number of hydraulic chambers to which hydraulic pressure is supplied is relatively reduced.   2. The variable valve operating apparatus for an internal combustion engine according to claim 1, wherein when the engine speed is low, the number of hydraulic chambers to which hydraulic pressure is supplied is relatively increased.   The variable valve operating system includes a variable lift operating angle mechanism that can control the intake air amount of the internal combustion engine by continuously expanding and reducing the lift operating angle of the intake valve according to the engine operating state. 2. The variable valve operating apparatus for an internal combustion engine according to claim 1, wherein when the amount is large, the number of hydraulic chambers to which hydraulic pressure is supplied is relatively increased.   The variable valve operating system for an internal combustion engine according to any one of claims 1 to 5, wherein hydraulic pressure is supplied from a single hydraulic source to a plurality of hydraulic chambers.

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