JP2013155695A - Variable valve device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a variable valve device for an internal combustion engine that can quickly start to adjust opening and closing timing at the start of the internal combustion engine with a simpler configuration than in a conventional device.SOLUTION: A variable valve device for an internal combustion engine includes: a vane rotor 11 having a plurality of vanes 14; a housing 12 that stores the vane rotor 11 therein so that an advance chamber 20 and a retard chamber 21 are formed on one side and on the other side in a circumferential direction of the respective vanes 14, respectively; a lock pin 26 that is inserted into a cylinder 24 provided in the vanes and is movable to a locked position and an unlocked position; and a guide path 29 that makes the first retard chamber 21A communicate with a cylinder 24. In the variable valve device where the lock pin 26 moves to the unlocked position by oil supplied to the cylinder 24 via the guide path 29, an oil supply port 52 to which a retard oil path 50 is connected is provided on an outer radial side from one end 29a of the guide path 29.

Description

  The present invention relates to a variable valve operating apparatus capable of controlling the opening / closing timing of at least one of an intake valve and an exhaust valve of an internal combustion engine.

  2. Description of the Related Art There is known a variable valve apparatus that can control the opening / closing timing of at least one of an intake valve and an exhaust valve by advancing or retarding a phase of a camshaft with respect to a crankshaft of an internal combustion engine. For example, a vane rotor that rotates integrally with the camshaft and a housing that houses the vane rotor and rotates together with the crankshaft are provided on one side of the vane of the vane rotor and provided on the other side of the vane. There is known a device for controlling the hydraulic pressure supplied to the retarded angle chamber to change the opening / closing timing. In such a device, when the internal combustion engine is stopped, the oil passage connected to the advance angle chamber and the oil passage connected to the retard angle chamber are closed, and the oil is retained in the oil passage, thereby the internal combustion engine. There is known an apparatus that quickly adjusts the opening / closing timing at the time of starting (see Patent Document 1). In addition, Patent Documents 2 and 3 exist as prior art documents related to the present invention.

JP 2007-138744 A JP 2010-261312 A Japanese Patent Laid-Open No. 06-009815

  In the apparatus of Patent Document 1, it is necessary to newly add a valve or add control of a switching valve in order to close the oil passage in the advance chamber and the oil passage in the retard chamber when the internal combustion engine is stopped. As a result, the cost may increase.

  Therefore, an object of the present invention is to provide a variable valve operating apparatus for an internal combustion engine that can start adjustment of the opening / closing timing quickly at the time of starting the internal combustion engine with a simpler configuration than the conventional one.

  A variable valve device according to the present invention includes a first rotating body having a plurality of vanes extending in a radial direction and rotating together with any one of a crankshaft and a camshaft of an internal combustion engine, the crankshaft and the cam The shaft rotates with either one of the shafts, and an advance chamber is formed on one side of each vane of the first rotating body, and a retard chamber is formed on the other side. In this way, the first rotating body is connected to a second rotating body that accommodates the first rotating body in a relatively rotatable manner, and a plurality of retarding chambers formed on the other side of each vane, respectively, and driven by the internal combustion engine. Inserted into a cylinder provided in at least one vane of the plurality of vanes and an oil supply passage for guiding oil sent from a supply source to each retardation chamber, A lock pin that can move between a lock position where a part of the recess is fitted and an unlock position where the entire cylinder is retracted, and one end that opens into a retard chamber adjacent to the vane provided with the cylinder. In the variable valve operating apparatus, the lock pin is moved to the unlock position by the oil supplied to the cylinder through the introduction passage. The oil supply port that opens to a retarded angle chamber that communicates with the introduction passage and is connected to the oil supply passage is provided to be positioned radially outward from one end of the introduction passage. Item 1).

  As is well known, when the supply of oil from the supply source is stopped, the oil in the retarded angle chamber is discharged to the outside through the oil supply passage. Therefore, even when the internal combustion engine is stopped, oil can be stored in a portion of the retarded chamber located below the oil supply port. According to the variable valve operating apparatus of the present invention, since the oil supply port is provided radially outside the one end of the introduction passage, the internal combustion engine is stopped in a state where the oil supply port is located above the one end of the introduction passage. In some cases, oil can be stored in the retarded angle chamber and the introduction passage. Therefore, the hydraulic pressure in the retarded angle chamber and the introduction passage can be quickly increased when the internal combustion engine is started. Therefore, the lock pin can be quickly moved to the unlock position when the internal combustion engine is started. Further, according to the variable valve operating apparatus of the present invention, it is not necessary to newly provide a valve or add control. Therefore, the adjustment of the opening / closing timing can be quickly started at the time of start-up with a simpler configuration than before.

  In one form of the variable valve operating apparatus of the present invention, the oil supply port may be provided so as to be located at the outermost radial direction in the retarded angle chamber communicating with the introduction passage (Claim 2). By providing the oil supply port at such a position, the amount of oil that accumulates in the retarded chamber when the internal combustion engine is stopped can be increased. Therefore, the hydraulic pressure in the retarded angle chamber and the introduction passage can be increased more quickly when the internal combustion engine is started.

  As described above, according to the variable valve operating apparatus of the present invention, the oil supply port is provided radially outward from one end of the introduction passage, so that oil can be stored in the retarding chamber and the introduction passage, respectively. it can. Therefore, the lock pin can be quickly moved to the unlock position when the internal combustion engine is started. Further, according to the variable valve operating apparatus of the present invention, it is not necessary to newly provide a valve or add control. Therefore, the adjustment of the opening / closing timing can be quickly started at the time of start-up with a simpler configuration than before.

The figure which shows the principal part of the internal combustion engine in which the intake side variable valve apparatus which concerns on one form of this invention was integrated. The figure which shows the cross section of the phase change mechanism in the II-II line | wire of FIG. The figure which shows the time change of the rotation speed of an internal combustion engine at the time of start-up of an internal combustion engine, the hydraulic pressure of a 1st retarded angle chamber, the hydraulic pressure of a hydraulic chamber, and the phase of an intake valve.

  FIG. 1 shows a main part of an internal combustion engine in which an intake side variable valve device according to an embodiment of the present invention is incorporated. The internal combustion engine 1 is a well-known internal combustion engine that has a plurality of cylinders and is mounted on a vehicle or the like as a driving power source. The internal combustion engine 1 is a series internal combustion engine in which a plurality of cylinders are arranged in series. Although not shown, the internal combustion engine 1 includes a crankshaft and a camshaft. The crankshaft is connected to a piston inserted into each cylinder via a connecting rod. The camshaft is formed with a plurality of cams for opening and closing intake valves provided in each cylinder. The camshaft is disposed in the cylinder head.

  Hereinafter, an intake side variable valve operating apparatus will be described as an example. A phase changing mechanism 10 is provided at one end of the camshaft. FIG. 2 shows a cross section of the phase changing mechanism 10 taken along the line II-II in FIG. As shown in FIG. 1, the phase changing mechanism 10 includes a vane rotor 11 as a first rotating body, and a housing 12 as a second rotating body in which the vane rotor 11 is accommodated coaxially. The vane rotor 11 is accommodated in the housing 12 so as to be rotatable relative to the housing 12. The vane rotor 11 includes a cylindrical rotor body 13 and four vanes 14 that extend radially outward from the rotor body 13. As shown in FIG. 2, the rotor body 13 is fixed to the camshaft by a center bolt 15.

  The housing 12 includes a sprocket 16 that is rotatably supported by the camshaft, a housing body 17, and a lid 18. A timing chain (not shown) is wound around the sprocket 16 so that the housing 12 rotates together with the crankshaft. As shown in FIG. 1, the housing body 17 includes a cylindrical outer wall portion 17a and four partition portions 17b extending radially inward from the outer wall portion 17a. As a result, four housing chambers 19 are formed inside the housing body 17. The vane rotor 11 is combined with the housing body 17 so that the vane 14 is disposed in the accommodation chamber 19. As shown in FIG. 2, the vane rotor 11 is accommodated in the housing 12 by closing one side of the housing body 17 in the direction of the rotation axis Ax with the sprocket 16 and the other side with the lid portion 18.

  As shown in FIG. 1, the interior of each storage chamber 19 is divided into an advance chamber 20 and a retard chamber 21 by the vane 14. Seal members 22 are respectively provided at the outer peripheral end portions of the vanes 14. The seal member 22 closes the gap between the vane 14 and the outer wall portion 17a. Moreover, the sealing member 23 is also provided in the edge part of the inner peripheral side of each partition part 17b, respectively. The seal member 23 closes a gap between the partition portion 17b and the rotor body 13.

  As shown in FIG. 1, one of the four vanes 14 is provided with a cylinder 24. Hereinafter, the vane 14 provided with the cylinder 24 may be referred to as the first vane 14A, and the other vanes 14 may be referred to as the second vane 14B. In addition, when it is not necessary to distinguish, it is only called the vane 14. As shown in FIG. 2, the cylinder 24 penetrates in the direction of the rotation axis Ax. The sprocket 16 is provided with a recess 25 that faces the cylinder 24 when the vane rotor 11 is in the position shown in FIG. A lock pin 26 is inserted into the cylinder 24 so as to be movable in the direction of the rotation axis Ax. The lock pin 26 includes a cylindrical main body 26a and a tip end portion 26b provided coaxially with the main body 26a. The diameter of the tip portion 26b is smaller than the diameter of the main body 26a. Therefore, a step 26c is formed between the main body 26a and the distal end portion 26b. The lock pin 26 is inserted into the cylinder 24 so that the tip end portion 26b is on the sprocket 16 side.

  The lock pin 26 moves to a lock position where the tip 26 b on the sprocket 16 side fits into the recess 25 and an unlock position where the entire lock pin 26 moves backward into the cylinder 24. FIG. 2 shows the lock pin 26 moved to the lock position. As shown in this figure, a hydraulic chamber 27 is formed between the main body 26a of the lock pin 26 and the vane 14 at the lock position. The recess 25 is provided with a restraining member 28 so that the hydraulic chamber 27 is formed in this way when the lock pin 26 is in the locked position. The hydraulic chamber 27 is formed such that oil supplied to the inside thereof pushes the lock pin 26 toward the unlock position. The retard chamber 21 and the hydraulic chamber 27 adjacent to the first vane 14 </ b> A communicate with each other through an introduction passage 29. Hereinafter, the retard chamber that communicates with the hydraulic chamber 27 may be referred to as the first retard chamber 21A, and the other retard chamber may be referred to as the second retard chamber 21B. In addition, when it is not necessary to distinguish, it is simply called the retarding chamber 21. A spring 30 that urges the lock pin 26 toward the sprocket 16 is provided in the cylinder 24.

  Oil is supplied to each advance chamber 20 and each retard chamber 21 by an oil supply device 40. As shown in FIG. 1, the oil supply device 40 includes an oil pump 42 as a supply source that pumps oil from an oil pan 2 of the internal combustion engine 1 through a strainer 41. The oil pump 42 is a known pump that is driven by the internal combustion engine 1. A supply passage 43 is connected to the discharge side of the oil pump 42. The supply passage 43 is provided with a filter 44 for removing foreign substances in the oil. The supply passage 43 branches into a main oil passage 45 and a valve operating oil passage 46 at a branch point 43a. The main oil passage 45 guides oil to an oil jet mechanism or the like for cooling the bearing and the piston that support the crankshaft. The valve operating oil passage 46 guides oil to the oil control valve 47. The valve operating oil passage 46 is provided with a check valve 48 that allows oil flow from the supply passage 43 to the oil control valve 47 and blocks oil flow from the oil control valve 47 to the supply passage 43. Yes. The oil control valve 47 is connected to each advance chamber 20 via an advance oil passage 49. The oil control valve 47 is connected to each retard chamber 21 through a retard oil passage 50 as an oil supply passage. The oil control valve 47 is configured such that the valve operating oil passage 46 is selectively connected to one of the advance oil passage 49 and the retard oil passage 50.

  The retarding oil passage 50 is branched into four branch passages 51 from the middle. In this figure, only two of the four are shown. Each retardation chamber 21 is provided with an oil supply port 52. The branch passage 51 is connected to the oil supply port 52. As shown in this figure, the oil supply port 52 is provided so as to be positioned at the outermost radial direction in the retard chamber 21. Therefore, the oil supply port 52 is located on the radially outer side of the end portion of the introduction passage 29 with respect to the one end 29 a that opens to the first retardation chamber 21 </ b> A.

  In the phase change mechanism 10, when the internal combustion engine 1 is stopped and the oil pump 42 is stopped, the oil in the retard chamber 21 is discharged from the oil supply port 52. Although not shown, a cam journal is provided at the lower part of the camshaft, and a cam cover is provided at the upper part of the camshaft. The oil discharged from the oil supply port 52 leaks from the joint between the cam journal and the cam cover and returns to the oil pan 2. In this figure, the position of the seam is indicated by a two-dot chain line OL. The retarding oil passage 50 (branch passage 51) connected to the oil supply port 52 has a U-shaped structure from the oil supply port 52 toward the engine head. Therefore, even if the oil gradually leaks from the joint and the oil level drops to the position of the joint, the oil is accumulated in the U-shaped branch passage 51. In this way, oil remains in the cylinder head even when the internal combustion engine 1 is stopped. Therefore, even if the internal combustion engine 1 is stopped, the oil level does not drop below the level indicated by the two-dot chain line OL. Further, since the oil is discharged from the oil supply port 52, the oil accumulates in a portion of the retard chamber 21 below the oil supply port 52. Therefore, the oil level does not become lower than the two-dot chain line OL in the right angle chamber 21 and the lower angle chamber 21 among the four retard chambers 21 shown in FIG. Further, in the retard chamber 21 at the left position and the upper position, the oil level does not become lower than the lower end of the oil supply port 52. As described above, in the variable valve operating apparatus of the present invention, oil is accumulated in the hatched portion of the retard chamber 21 even when the internal combustion engine 1 is stopped. Therefore, as shown in FIG. 1, even when the internal combustion engine 1 is stopped in a state where the first retarding chamber 21A is positioned above the camshaft, oil accumulates up to the oil level A in the first retarding chamber 21A. ing. In addition, since one end 29 a of the introduction passage 29 is located on the radially inner side with respect to the oil supply port 52, the oil is also accumulated in the introduction passage 29 and the hydraulic chamber 27.

  Next, the operation of the variable valve operating device will be described. The operation of the oil control valve 47 is controlled by an engine control unit (ECU) 60. The ECU 60 is a computer unit including a microprocessor and peripheral devices such as RAM and ROM necessary for its operation. The ECU 60 controls various control objects provided in the internal combustion engine 1 according to a predetermined control program, thereby controlling the internal combustion engine 1. The ECU 60 is connected to various sensors for acquiring the operating state of the internal combustion engine 1.

  The ECU 60 controls the oil control valve 47 so that the phase of the intake valve is most retarded for a certain time immediately after the internal combustion engine 1 is started. In this case, the ECU 60 controls the oil control valve 47 so that the valve operating oil passage 46 and the retarding oil passage 50 are connected. Then, the oil control valve 47 is controlled so that the intake valve is advanced after a predetermined time has elapsed. FIG. 3 shows temporal changes in the rotational speed of the internal combustion engine 1, the hydraulic pressure in the first retarding chamber 21A, the hydraulic pressure in the hydraulic chamber 27, and the phase of the intake valve when the internal combustion engine 1 is started. In this figure, as a comparative example, the oil pressure of the first retarding chamber 21A, the hydraulic pressure of the hydraulic chamber 27, and the phase of the intake valve when the oil supply port 52 is provided at the innermost radial direction in the retarding chamber 21 are shown. The change with time is shown by a broken line.

  In the present invention, as described above, oil remains in the first retardation chamber 21A, the introduction passage 29, and the hydraulic chamber 27 even when the internal combustion engine 1 is stopped. Therefore, as shown by the solid line in this figure, in the present invention, when cranking of the internal combustion engine 1 is started at time t1, the hydraulic pressure in the first retarding chamber 21A starts to increase from time t2. Accordingly, the hydraulic pressure in the hydraulic chamber 27 starts to increase from time t3. As a result, the lock pin 26 can be quickly moved to the unlock position. At time t5, the vane rotor 11 can be moved to change the phase of the intake valve to the advance side. At the time t5, the rotational speed of the internal combustion engine 1 is increasing. For this reason, the shearing force acting on the lock pin 26 is smaller than after the rotational speed has increased to the predetermined rotational speed N1. Accordingly, it is possible to suppress the lock pin 26 from biting into the recess 25 and to move the lock pin 26 to the unlock position with low hydraulic pressure.

  On the other hand, in the comparative example, the oil supply port 52 is provided at the innermost radial direction in the retard chamber 21. Therefore, when the internal combustion engine 1 stops at the position where the first retarding chamber 21A is shown in FIG. 1, almost all of the oil in the first retarding chamber 21A is discharged. Therefore, in the comparative example, the hydraulic pressure in the first hydraulic chamber 21A starts to increase from time t4. Therefore, in the case of the comparative example, the hydraulic pressure in the hydraulic chamber 27 starts to increase from time t6. At this time, since the rotational speed of the internal combustion engine 1 has increased to the predetermined rotational speed N1, the shearing force acting on the lock pin 26 increases. In this case, the lock pin 26 bites into the recess 25. Therefore, the hydraulic pressure required to move the lock pin 26 is increased. Therefore, the vane rotor 11 cannot be moved until time t7.

  As described above, according to the present invention, since the oil supply port 52 is provided at the outermost radial direction in the retarding chamber 21, the first retarding chamber 21A is located above the camshaft as shown in FIG. Even if the internal combustion engine 1 is stopped in the positioned state, the oil can be stored in the first retardation chamber 21A. Further, since the one end 29 a of the introduction passage 29 is located on the radially inner side with respect to the oil supply port 52, oil can be stored in the introduction passage 29 and the hydraulic chamber 27. Therefore, when the internal combustion engine 1 is started, the hydraulic pressure in the hydraulic chamber 27 can be quickly increased to move the lock pin 26 to the unlock position quickly. As a result, the phase of the intake valve can be rapidly advanced, so that the internal combustion engine 1 can be started quickly. Further, according to the present invention, it is not necessary to provide a new valve or add control. Therefore, the adjustment of the opening / closing timing of the intake valve can be quickly started at the start of the internal combustion engine 1 with a simpler configuration than the conventional one.

  In addition, the position where the oil supply port 52 is provided is not limited to the position shown in the above-described form, that is, the most radially outer position in the retard chamber 21. The oil supply port 52 may be provided so as to be positioned on the radially outer side than the one end 29 a of the introduction passage 29. Even in this case, when the internal combustion engine 1 is stopped, the oil can be stored in a portion of the first retardation chamber 21A below the oil supply port 52. The oil supply port 52 is located radially outside the one end 29 a of the introduction passage 29. Therefore, oil can be stored in the introduction passage 29 when the internal combustion engine 1 is stopped. Therefore, when the internal combustion engine 1 is started, the hydraulic pressure in the hydraulic chamber 27 can be quickly raised to move the lock pin 26 to the unlock position quickly.

  The present invention is not limited to the above-described form and can be implemented in various forms. For example, the internal combustion engine to which the present invention is applied is not limited to an in-line internal combustion engine. The present invention may be applied to a V-type internal combustion engine in which cylinders are arranged in a V-type and a horizontally opposed internal combustion engine in which cylinders are arranged horizontally.

  The number of lock pins in the present invention is not limited to one and may be two or more. In the present invention, the vane rotor may rotate with the crankshaft, and the housing may rotate with the camshaft. In addition, the present invention is not limited to the intake side variable valve device, but may be applied to the exhaust side variable valve device. For example, in the case of an exhaust-side variable valve device and a device in which the vane rotor is fixed on the advance side by a lock pin, the retard chamber in the above-described embodiment is an advance chamber, and the advance chamber is retarded. The present invention can be applied by replacing the chamber.

1 Internal combustion engine 11 Vane rotor (first rotating body)
12 Housing (second rotating body)
14 vane 20 advance chamber 21 retard chamber 24 cylinder 25 recess 26 lock pin 29 introduction passage 29a one end of introduction passage 42 oil pump (supply source)
50 Delay oil passage (oil supply passage)
52 Oil supply port

Claims (2)

A first rotating body having a plurality of vanes extending in the radial direction and rotating together with any one of a crankshaft and a camshaft of the internal combustion engine;
The crankshaft and the camshaft rotate together with the other, and an advance chamber is formed on one side of each vane in the circumferential direction of the first rotating body, and a retard angle is formed on the other side. A second rotator for accommodating the first rotator in a relatively rotatable manner so that the chambers are respectively formed;
An oil supply passage connected to each of the plurality of retard chambers formed on the other side of each vane, and guiding oil sent from a supply source driven by the internal combustion engine to each retard chamber;
A lock position that is inserted into a cylinder provided in at least one vane of the plurality of vanes, and partially fits into a recess provided in the second rotating body, and an unlock that is entirely retracted into the cylinder. A lock pin movable to the position,
An inlet passage having one end opened to a retarded angle chamber adjacent to the vane provided with the cylinder and passing through the retarded angle chamber and the cylinder; and
In the variable valve operating apparatus, the lock pin moves to the unlock position by the oil supplied to the cylinder through the introduction passage.
An oil supply port that opens to a retarded angle chamber that communicates with the introduction passage and is connected to the oil supply passage is provided so as to be positioned radially outward from one end of the introduction passage. apparatus.   2. The variable valve operating apparatus according to claim 1, wherein the oil supply port is provided so as to be located radially outward in a retarded angle chamber communicating with the introduction passage.

Images