JP4062224B2 - Valve timing control device - Google Patents

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.

  As a valve opening / closing timing control device, a housing member that rotates integrally with a crankshaft of an internal combustion engine, a rotor member that is assembled so as to be rotatable relative to the housing member and that rotates integrally with a camshaft, and is movable to the housing member In a device comprising a lock mechanism that controls the relative rotation by engaging and disengaging a lock member disposed on the rotor member with a receiving portion formed on the rotor member, and a hydraulic circuit that supplies and discharges hydraulic oil to and from the lock mechanism The urging force that is movably arranged in a direction perpendicular to or intersecting the axis and that urges the lock member toward the receiving portion is larger than a force that releases the lock member from the receiving portion (release hydraulic pressure), and the release hydraulic pressure In addition, when the rotational speed of the internal combustion engine is an idle rotational speed, the one that is set smaller than the centrifugal force acting on the lock member is set to control the lock mechanism. That (for example, see Patent Document 1.).

  However, according to this prior art, when the engine rotation is rapidly increased when the hydraulic pressure is not sufficiently supplied after starting the engine, the centrifugal force generated in the lock member may be larger than the urging force, and the lock member is detached from the receiving portion. This may cause the lock mechanism to be released.

Further, when a sufficient urging force is applied to the centrifugal force so as not to release the lock mechanism, a high operating hydraulic pressure is required to disengage the lock member from the receiving portion.
JP 2001-227311 A

  SUMMARY OF THE INVENTION Accordingly, it is a technical object of the present invention to reduce the influence of centrifugal force generated on a lock member in a valve opening / closing timing control device and prevent the lock mechanism from being released due to centrifugal force due to a sudden increase in engine speed.

In order to solve the above-mentioned problems, the technical means taken in the invention according to claim 1 includes a housing member that rotates integrally with one of a crankshaft or a camshaft of an internal combustion engine, and a relative rotation with respect to the housing member. A rotor member that is assembled so as to rotate integrally with the other of the camshaft or the crankshaft, and a lock member that is movably disposed on the housing member is engaged with and disengaged from a receiving portion formed on the rotor member. A valve opening / closing timing control device comprising a lock mechanism for controlling the relative rotation and a hydraulic circuit for supplying and discharging hydraulic oil to and from the lock mechanism, and applying a counter force in a direction opposite to the centrifugal force generated in the lock member. It has a centrifugal force canceling mechanism for generating the canceling mechanism includes a counter member movable, the other end one possible contact with the locking member It is that composed of the pivotally supported by a shaft member a can come into contact with the counter member.

According to the first aspect of the present invention, since the centrifugal force canceling mechanism that generates a counter force that opposes the centrifugal force generated in the lock member is provided, the lock mechanism can be easily released by the centrifugal force due to a sudden increase in the engine speed. Can be prevented with a simple structure .

  In order to solve the above-mentioned problem, the technical means taken in the invention of claim 2 is that the counter force is set smaller than the centrifugal force generated in the lock member.

  According to the second aspect of the present invention, the counter force is set to be smaller than the centrifugal force generated in the lock member, so that the hydraulic pressure for releasing the lock member from the receiving portion can be reduced.

  According to the present invention, since the influence of the centrifugal force generated on the lock member can be reduced, it is possible to prevent the lock mechanism from being released due to the centrifugal force due to the rapid increase in the engine speed.

  Embodiments of the present invention will be described below with reference to the drawings.

  A valve opening / closing timing control device 1 shown in FIGS. 1 to 4 includes a camshaft 10 that is rotatably supported by a cylinder head (not shown) of an internal combustion engine, and a rotor 20 that is integrally assembled at the tip of the camshaft 10. And a valve member 2 for opening and closing the valve. Further, the valve timing control apparatus 1 has a housing member 3 including a housing 30, a front plate 40, and a rear plate 50 that are assembled so as to be able to rotate relative to the rotor 20 within a predetermined range. A timing sprocket 31 is integrally formed on the outer periphery of the housing 30. Furthermore, a torsion spring 60 assembled between the rotor 20 and the front plate 40, four vanes 70 assembled to the rotor 20, a lock plate (lock member) 80 assembled to the housing 30, and the like are provided. Yes.

  As is well known, rotational power is transmitted to the timing sprocket 31 from a crankshaft (not shown) via a crank sprocket and a timing chain in a clockwise direction shown as a camshaft rotation direction in FIG.

  The camshaft 10 has a well-known cam (not shown) for opening and closing an intake valve or an exhaust valve (not shown), and an advance passage (hydraulic circuit) 11 extending in the axial direction of the camshaft 10 is provided inside the camshaft 10. An angular passage (hydraulic circuit) 12 and a lock passage (hydraulic circuit) 13 are provided. The advance passage 11 is connected to the first connection port 201 of the switching valve 200 through the radial passage 11a and the annular groove 11b provided in the camshaft 10 and the connection passage 15 provided in the cylinder head. The retard passage 12 is connected to the second connection port 202 of the switching valve 200 through the radial passage 12a and the annular groove 12b provided in the camshaft 10 and the connection passage 16 provided in the cylinder head. The lock passage 13 is connected to the third connection port 203 of the switching valve 200 through the radial passage 12a and the annular groove 13b provided in the camshaft 10 and the connection passage 17 provided in the cylinder head.

  The switching valve 200 is a known valve that moves a spool (not shown) against a spring by energizing and controlling the solenoid 204. As shown in FIG. 1, the control valve 200 includes a supply port 206 a and a connection port 206 b connected to an oil pump 205 driven by an internal combustion engine in communication with a first connection port 201 and a third connection port 203, respectively. The port 202 is configured to communicate with the discharge port 207. The control valve 200 is configured such that the supply port 206 a is disconnected from the first connection port 201 and the second connection port 202, and the supply port 206 b communicates with the third connection port 203. The control valve 200 is configured such that the supply ports 206a and 206b communicate with the second connection port 202 and the third connection port 203, respectively, and the first connection port 201 communicates with the discharge port 207. The control valve 200 is configured such that the first connection port 201, the second connection port 202, and the third connection port 203 communicate with the discharge port 207 when the internal combustion engine is stopped and started.

  As shown in FIG. 2, the housing 30, which is the main element of the housing member 3, is provided with a plurality of protrusions 33 that support the rotor 20 on the inner peripheral surface thereof so as to be relatively rotatable. A plurality of fluid pressure chambers R0 arranged in parallel along the relative rotation direction (arrows S1 and S2 directions) are formed by the adjacent protrusions 33 and the rotor 20.

  As shown in FIG. 2, a plurality of vane grooves 21 are radially formed on the outer peripheral portion of the rotor 20 so as to face each fluid pressure chamber R <b> 0 at a predetermined interval. A vane 70 that functions as a partition member is slidably inserted in each vane groove 21 along the radial direction. The vane 70 divides each fluid pressure chamber R0 into the advance chamber R1 and the retard chamber R2 in the relative rotation direction of the housing 30 and the rotor 20 (directions of arrows S1 and S2) and rotates integrally with the rotor 20. The advance chamber R1 communicates with the advance passage 11 through a radial oil passage 23a and an oil passage 23b formed in the axial center of the rotor 20. The retard chamber R2 communicates with the retard passage 12 via a radial oil passage 24a and an axial oil passage 24b.

  As shown in FIG. 2, a lock oil passage 22 is formed in the outer peripheral portion of the rotor 20. A lock groove 22A is formed at one end of the lock oil passage 22 to constitute a lock mechanism, which will be described later, and to prevent the relative rotation phase from moving further in the advance direction (arrow S1 direction) from the intermediate phase. Further, a lock groove 22B is formed at the other end of the lock oil passage 22 to constitute a lock mechanism, which will be described later, and to prevent the relative rotation phase from moving further in the retard direction (arrow S1 direction) from the intermediate phase. Yes.

  As shown in FIG. 2, the protrusion 33 of the housing 30 has a lock mechanism that mechanically holds the relative rotational phase of the housing 30 and the rotor 20 at an intermediate phase that is intermediate between the most advanced angle phase and the most retarded angle phase. The lock part 8A and the lock part 8B which comprise are attached. The lock portion 8A (advance angle lock portion) prevents the rotor 20 from moving in the advance angle direction (direction S1). The lock portion 8B (retarding lock portion) prevents the rotor 20 from moving in the retarding direction (S2 direction). The advance lock portion 8A includes a plate-shaped lock body 60 and a spring 81 that urges the lock plate 80 in the radially inward direction that is the lock direction. Similarly to the advance lock portion 8A, the retard lock portion 8B includes a plate-shaped lock plate 80 and a spring 81 that urges the lock plate 80 radially inward as the lock direction. The shape of the lock plate 80 is not limited to the plate shape.

  As shown in FIGS. 2 to 4, a guide groove 36 is formed in the radial direction between the lock portion 8 </ b> A and the lock portion 8 </ b> B of the protrusion 33. A counterweight 91 that is movable in the radial direction is inserted into the guide groove 36. A fulcrum hole 35 a is formed in the middle of each of the lock portions 8 </ b> A and 8 </ b> B of the protrusion 33 and the guide groove 36. A fulcrum shaft 35b integrally provided with an arm 90 is inserted into the fulcrum hole 35a in a swingable manner. A fulcrum structure 35 is constituted by the fulcrum hole 35a and the fulcrum shaft 35b. One end of the arm 90 is in contact with the lock plate 80 and the other end is in contact with the counterweight 91. When centrifugal force due to rotation is generated radially outward on the counterweight 91, the arm 90 is swung via the fulcrum structure 35 and counter force is generated radially inward on the lock plate 80. The counter force acts on the lock plate 80 so as to oppose the centrifugal force generated on the lock plate 80. Thereby, it is possible to prevent the lock mechanism from being released due to the centrifugal force due to the rapid increase in the engine speed. The guide groove 36 may be communicated with the outside. Thereby, the oil staying in the guide groove 36 can be discharged, and the operation of the counterweight 91 can be made smooth.

  As shown in FIG. 2, when the hydraulic oil in the lock oil passage 22 is discharged and the relative rotational phase of the housing 30 and the rotor 20 is an intermediate phase, the lock plate 80 of the lock portion 8 </ b> A for advancing by the urging force of the spring 81. Is urged in the radially inward direction, which is the locking direction, and the front end of the lock plate 80 is engaged with the lock groove 22A. Similarly, the lock plate 80 of the retard lock portion 8B is urged in the radially inward direction, which is the lock direction, by the urging force of the spring 81, and the lock plate 80 of the retard lock portion 8B is pushed into the lock groove 22B. The tip is engaged. Thereby, the relative rotational phase of the housing 30 and the rotor 20 is locked.

  When the relative rotational phase of the housing 30 and the rotor 20 is locked in this way, the housing 30 and the rotor 20 can rotate together. In the present embodiment, as described above, when the relative rotational phase of the housing 30 and the rotor 20 is an intermediate phase between the most advanced angle phase and the most retarded angle phase, that is, the phase of the vane 70 is in the fluid pressure chamber R0. The opening / closing timing timing of the engine valve is set so that the engine can be smoothly started when the intermediate phase is intermediate between the most advanced angle phase and the most retarded angle phase.

  The operation of the valve timing control apparatus 1 of the present embodiment configured as described above will be described.

  FIG. 2 shows a valve opening / closing timing control device at the time of starting. At the time of starting, the hydraulic oil in the advance chamber R1 and the retard chamber R2 is discharged, and the hydraulic oil in the lock oil passage 22 is also discharged. For this reason, the lock plate 80 moves radially inward, and the lock portions 8A and 8B are locked. As a result, the engine can be started when the rotational phase is in the intermediate phase, and smooth startability can be obtained.

  By the way, after the engine is started, when the engine rotation is at the idle rotation speed, as shown in FIG. 2, the lock plate 80 is locked by the urging force of the spring 81 that urges the lock plate 80 in the radially inward direction. , 22B, and the locking mechanism can be locked. Further, after starting the engine, by controlling the control valve 200, hydraulic oil is supplied from the oil pump 205 to the advance chamber R1, the retard chamber R2, and the lock oil passage 22, and the relative rotational phase is set to the intermediate phase. .

  However, immediately after the engine is started, the hydraulic oil is not sufficiently supplied to the advance chamber R1, the retard chamber R2, and the lock oil passage 22. Further, when the engine speed increases rapidly, as shown in FIG. 3, the centrifugal force generated in the lock plate 80 may be larger than the urging force of the spring 81, and the lock plate 80 is detached from the lock grooves 22A and 22B and locked. May cause release.

  However, in this embodiment, when a centrifugal force due to rotation is generated in the counterweight 91 radially outward, the arm 90 is swung via the fulcrum structure 35 and a counter force is generated in the lock plate 80 radially inward. The counter force acts on the lock plate 80 so as to oppose the centrifugal force generated on the lock plate 80, and is added to the urging force that urges the lock plate 80 of the spring 81 in the radially inward direction. The lock grooves 22A and 22B are engaged. Thereby, it is possible to prevent the lock mechanism from being released due to the centrifugal force due to the rapid increase in the engine speed.

  When the relative rotation phase of the housing 30 and the rotor 20 is changed according to the driving conditions of the engine, the advance lock section 8A and the retard lock section 8B are released. In this case, oil is supplied to the lock oil passage 22 through the lock oil passage 25, and the pressure surface of the lock plate 80 of the lock portions 8A and 8B is pressurized by the oil pressure of the lock oil passage 22, and the lock plate 80 is moved outward in the radial direction to release the lock. Thus, when the lock portions 8A and 8B are unlocked, the housing 30 and the rotor 20 can be rotated relative to each other, and the rotational phase of the camshaft 10 is retarded with respect to the rotational phase of the crankshaft according to the driving conditions of the engine. The engine output characteristics can be adjusted by adjusting the direction (arrow S1 direction) or the advance direction (arrow S2 direction) as necessary.

It is a longitudinal cross-sectional view of the valve timing control apparatus according to the embodiment of the present invention. It is AA sectional drawing of FIG. 1 which shows the state by which the locking mechanism of the valve timing control apparatus was locked. It is AA sectional drawing of FIG. 1 which shows the state by which the locking mechanism of the valve timing control apparatus was cancelled | released. It is the L section enlarged view of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Valve opening / closing timing control device 2 ... Rotor member 3 ... Housing member 10 ... Cam shaft 13 ... Lock passage (hydraulic circuit)
22A, 22B ... Lock groove (receiving part: lock mechanism)
70 ... Vane 80 ... Lock plate (Lock member: Lock mechanism)
90 ... arm (shaft member: cancellation mechanism)
91 ... Counter weight (counter member: cancel mechanism)

Claims (2)

A housing member that rotates integrally with one of the crankshaft or camshaft of the internal combustion engine;
A rotor member that is assembled to the housing member so as to be relatively rotatable, and rotates integrally with the other of the camshaft or the crankshaft;
A lock mechanism that is movably disposed on the housing member and engages / disengages with a receiving portion formed on the rotor member to control relative rotation of the two members;
In a valve opening / closing timing control device comprising a hydraulic circuit for supplying and discharging hydraulic oil to and from the lock mechanism,
Have a centrifugal force canceling mechanism for generating a counter force in a direction opposite to the centrifugal force generated in the locking member, wherein the canceling mechanism includes a counter member movable, the other end one possible contact with the locking member A valve opening / closing timing control device comprising: a shaft member that is capable of contacting the counter member and is swingably supported .   The valve opening / closing timing control device according to claim 1, wherein the counter force is set to be smaller than a centrifugal force generated in the lock member.

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